Merge branch 'pm-devfreq'

* pm-devfreq:
  PM / devfreq: style/typo fixes
  PM / devfreq: exynos: Add the detailed correlation for Exynos5422 bus
  PM / devfreq: event: Find the instance of devfreq-event device by using phandle
  PM / devfreq: event: Add new Exynos NoC probe driver
  MAINTAINERS: Add samsung bus frequency driver entry
  PM / devfreq: exynos: Remove unused exynos4/5 busfreq driver
  PM / devfreq: exynos: Add the detailed correlation between sub-blocks and power line
  PM / devfreq: exynos: Update documentation for bus devices using passive governor
  PM / devfreq: exynos: Add support of bus frequency of sub-blocks using passive governor
  PM / devfreq: Add new passive governor
  PM / devfreq: Add new DEVFREQ_TRANSITION_NOTIFIER notifier
  PM / devfreq: Add devfreq_get_devfreq_by_phandle()
  PM / devfreq: exynos: Add documentation for generic exynos bus frequency driver
  PM / devfreq: exynos: Add generic exynos bus frequency driver

Documentation/devicetree/bindings/devfreq/event/exynos-nocp.txt

+
+* Samsung Exynos NoC (Network on Chip) Probe device
+
+The Samsung Exynos542x SoC has NoC (Network on Chip) Probe for NoC bus.
+NoC provides the primitive values to get the performance data. The packets
+that the Network on Chip (NoC) probes detects are transported over
+the network infrastructure to observer units. You can configure probes to
+capture packets with header or data on the data request response network,
+or as traffic debug or statistic collectors. Exynos542x bus has multiple
+NoC probes to provide bandwidth information about behavior of the SoC
+that you can use while analyzing system performance.
+
+Required properties:
+- compatible: Should be "samsung,exynos5420-nocp"
+- reg: physical base address of each NoC Probe and length of memory mapped region.
+
+Optional properties:
+- clock-names : the name of clock used by the NoC Probe, "nocp"
+- clocks : phandles for clock specified in "clock-names" property
+
+Example : NoC Probe nodes in Device Tree are listed below.
+
+	nocp_mem0_0: nocp@10CA1000 {
+		compatible = "samsung,exynos5420-nocp";
+		reg = <0x10CA1000 0x200>;
+	};

Documentation/devicetree/bindings/devfreq/exynos-bus.txt

+* Generic Exynos Bus frequency device
+
+The Samsung Exynos SoC has many buses for data transfer between DRAM
+and sub-blocks in SoC. Most Exynos SoCs share the common architecture
+for buses. Generally, each bus of Exynos SoC includes a source clock
+and a power line, which are able to change the clock frequency
+of the bus in runtime. To monitor the usage of each bus in runtime,
+the driver uses the PPMU (Platform Performance Monitoring Unit), which
+is able to measure the current load of sub-blocks.
+
+The Exynos SoC includes the various sub-blocks which have the each AXI bus.
+The each AXI bus has the owned source clock but, has not the only owned
+power line. The power line might be shared among one more sub-blocks.
+So, we can divide into two type of device as the role of each sub-block.
+There are two type of bus devices as following:
+- parent bus device
+- passive bus device
+
+Basically, parent and passive bus device share the same power line.
+The parent bus device can only change the voltage of shared power line
+and the rest bus devices (passive bus device) depend on the decision of
+the parent bus device. If there are three blocks which share the VDD_xxx
+power line, Only one block should be parent device and then the rest blocks
+should depend on the parent device as passive device.
+
+	VDD_xxx |--- A block (parent)
+		|--- B block (passive)
+		|--- C block (passive)
+
+There are a little different composition among Exynos SoC because each Exynos
+SoC has different sub-blocks. Therefore, such difference should be specified
+in devicetree file instead of each device driver. In result, this driver
+is able to support the bus frequency for all Exynos SoCs.
+
+Required properties for all bus devices:
+- compatible: Should be "samsung,exynos-bus".
+- clock-names : the name of clock used by the bus, "bus".
+- clocks : phandles for clock specified in "clock-names" property.
+- operating-points-v2: the OPP table including frequency/voltage information
+  to support DVFS (Dynamic Voltage/Frequency Scaling) feature.
+
+Required properties only for parent bus device:
+- vdd-supply: the regulator to provide the buses with the voltage.
+- devfreq-events: the devfreq-event device to monitor the current utilization
+  of buses.
+
+Required properties only for passive bus device:
+- devfreq: the parent bus device.
+
+Optional properties only for parent bus device:
+- exynos,saturation-ratio: the percentage value which is used to calibrate
+			the performance count against total cycle count.
+- exynos,voltage-tolerance: the percentage value for bus voltage tolerance
+			which is used to calculate the max voltage.
+
+Detailed correlation between sub-blocks and power line according to Exynos SoC:
+- In case of Exynos3250, there are two power line as following:
+	VDD_MIF |--- DMC
+
+	VDD_INT |--- LEFTBUS (parent device)
+		|--- PERIL
+		|--- MFC
+		|--- G3D
+		|--- RIGHTBUS
+		|--- PERIR
+		|--- FSYS
+		|--- LCD0
+		|--- PERIR
+		|--- ISP
+		|--- CAM
+
+- In case of Exynos4210, there is one power line as following:
+	VDD_INT |--- DMC (parent device)
+		|--- LEFTBUS
+		|--- PERIL
+		|--- MFC(L)
+		|--- G3D
+		|--- TV
+		|--- LCD0
+		|--- RIGHTBUS
+		|--- PERIR
+		|--- MFC(R)
+		|--- CAM
+		|--- FSYS
+		|--- GPS
+		|--- LCD0
+		|--- LCD1
+
+- In case of Exynos4x12, there are two power line as following:
+	VDD_MIF |--- DMC
+
+	VDD_INT |--- LEFTBUS (parent device)
+		|--- PERIL
+		|--- MFC(L)
+		|--- G3D
+		|--- TV
+		|--- IMAGE
+		|--- RIGHTBUS
+		|--- PERIR
+		|--- MFC(R)
+		|--- CAM
+		|--- FSYS
+		|--- GPS
+		|--- LCD0
+		|--- ISP
+
+- In case of Exynos5422, there are two power line as following:
+	VDD_MIF |--- DREX 0 (parent device, DRAM EXpress controller)
+	        |--- DREX 1
+
+	VDD_INT |--- NoC_Core (parent device)
+		|--- G2D
+		|--- G3D
+		|--- DISP1
+		|--- NoC_WCORE
+		|--- GSCL
+		|--- MSCL
+		|--- ISP
+		|--- MFC
+		|--- GEN
+		|--- PERIS
+		|--- PERIC
+		|--- FSYS
+		|--- FSYS2
+
+Example1:
+	Show the AXI buses of Exynos3250 SoC. Exynos3250 divides the buses to
+	power line (regulator). The MIF (Memory Interface) AXI bus is used to
+	transfer data between DRAM and CPU and uses the VDD_MIF regulator.
+
+	- MIF (Memory Interface) block
+	: VDD_MIF |--- DMC (Dynamic Memory Controller)
+
+	- INT (Internal) block
+	: VDD_INT |--- LEFTBUS (parent device)
+		  |--- PERIL
+		  |--- MFC
+		  |--- G3D
+		  |--- RIGHTBUS
+		  |--- FSYS
+		  |--- LCD0
+		  |--- PERIR
+		  |--- ISP
+		  |--- CAM
+
+	- MIF bus's frequency/voltage table
+	-----------------------
+	|Lv| Freq   | Voltage |
+	-----------------------
+	|L1| 50000  |800000   |
+	|L2| 100000 |800000   |
+	|L3| 134000 |800000   |
+	|L4| 200000 |825000   |
+	|L5| 400000 |875000   |
+	-----------------------
+
+	- INT bus's frequency/voltage table
+	----------------------------------------------------------
+	|Block|LEFTBUS|RIGHTBUS|MCUISP |ISP    |PERIL  ||VDD_INT |
+	| name|       |LCD0    |       |       |       ||        |
+	|     |       |FSYS    |       |       |       ||        |
+	|     |       |MFC     |       |       |       ||        |
+	----------------------------------------------------------
+	|Mode |*parent|passive |passive|passive|passive||        |
+	----------------------------------------------------------
+	|Lv   |Frequency                               ||Voltage |
+	----------------------------------------------------------
+	|L1   |50000  |50000   |50000  |50000  |50000  ||900000  |
+	|L2   |80000  |80000   |80000  |80000  |80000  ||900000  |
+	|L3   |100000 |100000  |100000 |100000 |100000 ||1000000 |
+	|L4   |134000 |134000  |200000 |200000 |       ||1000000 |
+	|L5   |200000 |200000  |400000 |300000 |       ||1000000 |
+	----------------------------------------------------------
+
+Example2 :
+	The bus of DMC (Dynamic Memory Controller) block in exynos3250.dtsi
+	is listed below:
+
+	bus_dmc: bus_dmc {
+		compatible = "samsung,exynos-bus";
+		clocks = <&cmu_dmc CLK_DIV_DMC>;
+		clock-names = "bus";
+		operating-points-v2 = <&bus_dmc_opp_table>;
+		status = "disabled";
+	};
+
+	bus_dmc_opp_table: opp_table1 {
+		compatible = "operating-points-v2";
+		opp-shared;
+
+		opp@50000000 {
+			opp-hz = /bits/ 64 <50000000>;
+			opp-microvolt = <800000>;
+		};
+		opp@100000000 {
+			opp-hz = /bits/ 64 <100000000>;
+			opp-microvolt = <800000>;
+		};
+		opp@134000000 {
+			opp-hz = /bits/ 64 <134000000>;
+			opp-microvolt = <800000>;
+		};
+		opp@200000000 {
+			opp-hz = /bits/ 64 <200000000>;
+			opp-microvolt = <825000>;
+		};
+		opp@400000000 {
+			opp-hz = /bits/ 64 <400000000>;
+			opp-microvolt = <875000>;
+		};
+	};
+
+	bus_leftbus: bus_leftbus {
+		compatible = "samsung,exynos-bus";
+		clocks = <&cmu CLK_DIV_GDL>;
+		clock-names = "bus";
+		operating-points-v2 = <&bus_leftbus_opp_table>;
+		status = "disabled";
+	};
+
+	bus_rightbus: bus_rightbus {
+		compatible = "samsung,exynos-bus";
+		clocks = <&cmu CLK_DIV_GDR>;
+		clock-names = "bus";
+		operating-points-v2 = <&bus_leftbus_opp_table>;
+		status = "disabled";
+	};
+
+	bus_lcd0: bus_lcd0 {
+		compatible = "samsung,exynos-bus";
+		clocks = <&cmu CLK_DIV_ACLK_160>;
+		clock-names = "bus";
+		operating-points-v2 = <&bus_leftbus_opp_table>;
+		status = "disabled";
+	};
+
+	bus_fsys: bus_fsys {
+		compatible = "samsung,exynos-bus";
+		clocks = <&cmu CLK_DIV_ACLK_200>;
+		clock-names = "bus";
+		operating-points-v2 = <&bus_leftbus_opp_table>;
+		status = "disabled";
+	};
+
+	bus_mcuisp: bus_mcuisp {
+		compatible = "samsung,exynos-bus";
+		clocks = <&cmu CLK_DIV_ACLK_400_MCUISP>;
+		clock-names = "bus";
+		operating-points-v2 = <&bus_mcuisp_opp_table>;
+		status = "disabled";
+	};
+
+	bus_isp: bus_isp {
+		compatible = "samsung,exynos-bus";
+		clocks = <&cmu CLK_DIV_ACLK_266>;
+		clock-names = "bus";
+		operating-points-v2 = <&bus_isp_opp_table>;
+		status = "disabled";
+	};
+
+	bus_peril: bus_peril {
+		compatible = "samsung,exynos-bus";
+		clocks = <&cmu CLK_DIV_ACLK_100>;
+		clock-names = "bus";
+		operating-points-v2 = <&bus_peril_opp_table>;
+		status = "disabled";
+	};
+
+	bus_mfc: bus_mfc {
+		compatible = "samsung,exynos-bus";
+		clocks = <&cmu CLK_SCLK_MFC>;
+		clock-names = "bus";
+		operating-points-v2 = <&bus_leftbus_opp_table>;
+		status = "disabled";
+	};
+
+	bus_leftbus_opp_table: opp_table1 {
+		compatible = "operating-points-v2";
+		opp-shared;
+
+		opp@50000000 {
+			opp-hz = /bits/ 64 <50000000>;
+			opp-microvolt = <900000>;
+		};
+		opp@80000000 {
+			opp-hz = /bits/ 64 <80000000>;
+			opp-microvolt = <900000>;
+		};
+		opp@100000000 {
+			opp-hz = /bits/ 64 <100000000>;
+			opp-microvolt = <1000000>;
+		};
+		opp@134000000 {
+			opp-hz = /bits/ 64 <134000000>;
+			opp-microvolt = <1000000>;
+		};
+		opp@200000000 {
+			opp-hz = /bits/ 64 <200000000>;
+			opp-microvolt = <1000000>;
+		};
+	};
+
+	bus_mcuisp_opp_table: opp_table2 {
+		compatible = "operating-points-v2";
+		opp-shared;
+
+		opp@50000000 {
+			opp-hz = /bits/ 64 <50000000>;
+		};
+		opp@80000000 {
+			opp-hz = /bits/ 64 <80000000>;
+		};
+		opp@100000000 {
+			opp-hz = /bits/ 64 <100000000>;
+		};
+		opp@200000000 {
+			opp-hz = /bits/ 64 <200000000>;
+		};
+		opp@400000000 {
+			opp-hz = /bits/ 64 <400000000>;
+		};
+	};
+
+	bus_isp_opp_table: opp_table3 {
+		compatible = "operating-points-v2";
+		opp-shared;
+
+		opp@50000000 {
+			opp-hz = /bits/ 64 <50000000>;
+		};
+		opp@80000000 {
+			opp-hz = /bits/ 64 <80000000>;
+		};
+		opp@100000000 {
+			opp-hz = /bits/ 64 <100000000>;
+		};
+		opp@200000000 {
+			opp-hz = /bits/ 64 <200000000>;
+		};
+		opp@300000000 {
+			opp-hz = /bits/ 64 <300000000>;
+		};
+	};
+
+	bus_peril_opp_table: opp_table4 {
+		compatible = "operating-points-v2";
+		opp-shared;
+
+		opp@50000000 {
+			opp-hz = /bits/ 64 <50000000>;
+		};
+		opp@80000000 {
+			opp-hz = /bits/ 64 <80000000>;
+		};
+		opp@100000000 {
+			opp-hz = /bits/ 64 <100000000>;
+		};
+	};
+
+
+	Usage case to handle the frequency and voltage of bus on runtime
+	in exynos3250-rinato.dts is listed below:
+
+	&bus_dmc {
+		devfreq-events = <&ppmu_dmc0_3>, <&ppmu_dmc1_3>;
+		vdd-supply = <&buck1_reg>;	/* VDD_MIF */
+		status = "okay";
+	};
+
+	&bus_leftbus {
+		devfreq-events = <&ppmu_leftbus_3>, <&ppmu_rightbus_3>;
+		vdd-supply = <&buck3_reg>;
+		status = "okay";
+	};
+
+	&bus_rightbus {
+		devfreq = <&bus_leftbus>;
+		status = "okay";
+	};
+
+	&bus_lcd0 {
+		devfreq = <&bus_leftbus>;
+		status = "okay";
+	};
+
+	&bus_fsys {
+		devfreq = <&bus_leftbus>;
+		status = "okay";
+	};
+
+	&bus_mcuisp {
+		devfreq = <&bus_leftbus>;
+		status = "okay";
+	};
+
+	&bus_isp {
+		devfreq = <&bus_leftbus>;
+		status = "okay";
+	};
+
+	&bus_peril {
+		devfreq = <&bus_leftbus>;
+		status = "okay";
+	};
+
+	&bus_mfc {
+		devfreq = <&bus_leftbus>;
+		status = "okay";
+	};

MAINTAINERS

@@ -3540,6 +3540,15 @@ F:	drivers/devfreq/devfreq-event.c
 F:	include/linux/devfreq-event.h
 F:	Documentation/devicetree/bindings/devfreq/event/
 
+BUS FREQUENCY DRIVER FOR SAMSUNG EXYNOS
+M:	Chanwoo Choi <cw00.choi@samsung.com>
+L:	linux-pm@vger.kernel.org
+L:	linux-samsung-soc@vger.kernel.org
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq.git
+S:	Maintained
+F:	drivers/devfreq/exynos-bus.c
+F:	Documentation/devicetree/bindings/devfreq/exynos-bus.txt
+
 DEVICE NUMBER REGISTRY
 M:	Torben Mathiasen <device@lanana.org>
 W:	http://lanana.org/docs/device-list/index.html

drivers/devfreq/Kconfig

@@ -64,30 +64,32 @@ config DEVFREQ_GOV_USERSPACE
 	  Otherwise, the governor does not change the frequency
 	  given at the initialization.
 
+config DEVFREQ_GOV_PASSIVE
+	tristate "Passive"
+	help
+	  Sets the frequency based on the frequency of its parent devfreq
+	  device. This governor does not change the frequency by itself
+	  through sysfs entries. The passive governor recommends that
+	  devfreq device uses the OPP table to get the frequency/voltage.
+
 comment "DEVFREQ Drivers"
 
-config ARM_EXYNOS4_BUS_DEVFREQ
-	bool "ARM Exynos4210/4212/4412 Memory Bus DEVFREQ Driver"
-	depends on (CPU_EXYNOS4210 || SOC_EXYNOS4212 || SOC_EXYNOS4412) && !ARCH_MULTIPLATFORM
+config ARM_EXYNOS_BUS_DEVFREQ
+	bool "ARM EXYNOS Generic Memory Bus DEVFREQ Driver"
+	depends on ARCH_EXYNOS
 	select DEVFREQ_GOV_SIMPLE_ONDEMAND
+	select DEVFREQ_GOV_PASSIVE
+	select DEVFREQ_EVENT_EXYNOS_PPMU
+	select PM_DEVFREQ_EVENT
 	select PM_OPP
 	help
-	  This adds the DEVFREQ driver for Exynos4210 memory bus (vdd_int)
-	  and Exynos4212/4412 memory interface and bus (vdd_mif + vdd_int).
-	  It reads PPMU counters of memory controllers and adjusts
-	  the operating frequencies and voltages with OPP support.
+	  This adds the common DEVFREQ driver for Exynos Memory bus. Exynos
+	  Memory bus has one more group of memory bus (e.g, MIF and INT block).
+	  Each memory bus group could contain many memoby bus block. It reads
+	  PPMU counters of memory controllers by using DEVFREQ-event device
+	  and adjusts the operating frequencies and voltages with OPP support.
 	  This does not yet operate with optimal voltages.
 
-config ARM_EXYNOS5_BUS_DEVFREQ
-	tristate "ARM Exynos5250 Bus DEVFREQ Driver"
-	depends on SOC_EXYNOS5250
-	select DEVFREQ_GOV_SIMPLE_ONDEMAND
-	select PM_OPP
-	help
-	  This adds the DEVFREQ driver for Exynos5250 bus interface (vdd_int).
-	  It reads PPMU counters of memory controllers and adjusts the
-	  operating frequencies and voltages with OPP support.
-
 config ARM_TEGRA_DEVFREQ
        tristate "Tegra DEVFREQ Driver"
        depends on ARCH_TEGRA_124_SOC

drivers/devfreq/Makefile

@@ -4,10 +4,10 @@ obj-$(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND)	+= governor_simpleondemand.o
 obj-$(CONFIG_DEVFREQ_GOV_PERFORMANCE)	+= governor_performance.o
 obj-$(CONFIG_DEVFREQ_GOV_POWERSAVE)	+= governor_powersave.o
 obj-$(CONFIG_DEVFREQ_GOV_USERSPACE)	+= governor_userspace.o
+obj-$(CONFIG_DEVFREQ_GOV_PASSIVE)	+= governor_passive.o
 
 # DEVFREQ Drivers
-obj-$(CONFIG_ARM_EXYNOS4_BUS_DEVFREQ)	+= exynos/
-obj-$(CONFIG_ARM_EXYNOS5_BUS_DEVFREQ)	+= exynos/
+obj-$(CONFIG_ARM_EXYNOS_BUS_DEVFREQ)	+= exynos-bus.o
 obj-$(CONFIG_ARM_TEGRA_DEVFREQ)		+= tegra-devfreq.o
 
 # DEVFREQ Event Drivers

drivers/devfreq/devfreq-event.c

@@ -234,6 +234,11 @@ struct devfreq_event_dev *devfreq_event_get_edev_by_phandle(struct device *dev,
 		return ERR_PTR(-ENODEV);
 
 	mutex_lock(&devfreq_event_list_lock);
+	list_for_each_entry(edev, &devfreq_event_list, node) {
+		if (edev->dev.parent && edev->dev.parent->of_node == node)
+			goto out;
+	}
+
 	list_for_each_entry(edev, &devfreq_event_list, node) {
 		if (!strcmp(edev->desc->name, node->name))
 			goto out;

drivers/devfreq/devfreq.c

@@ -25,6 +25,7 @@
 #include <linux/list.h>
 #include <linux/printk.h>
 #include <linux/hrtimer.h>
+#include <linux/of.h>
 #include "governor.h"
 
 static struct class *devfreq_class;
@@ -188,6 +189,29 @@ static struct devfreq_governor *find_devfreq_governor(const char *name)
 	return ERR_PTR(-ENODEV);
 }
 
+static int devfreq_notify_transition(struct devfreq *devfreq,
+		struct devfreq_freqs *freqs, unsigned int state)
+{
+	if (!devfreq)
+		return -EINVAL;
+
+	switch (state) {
+	case DEVFREQ_PRECHANGE:
+		srcu_notifier_call_chain(&devfreq->transition_notifier_list,
+				DEVFREQ_PRECHANGE, freqs);
+		break;
+
+	case DEVFREQ_POSTCHANGE:
+		srcu_notifier_call_chain(&devfreq->transition_notifier_list,
+				DEVFREQ_POSTCHANGE, freqs);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 /* Load monitoring helper functions for governors use */
 
 /**
@@ -199,7 +223,8 @@ static struct devfreq_governor *find_devfreq_governor(const char *name)
  */
 int update_devfreq(struct devfreq *devfreq)
 {
-	unsigned long freq;
+	struct devfreq_freqs freqs;
+	unsigned long freq, cur_freq;
 	int err = 0;
 	u32 flags = 0;
 
@@ -233,10 +258,22 @@ int update_devfreq(struct devfreq *devfreq)
 		flags |= DEVFREQ_FLAG_LEAST_UPPER_BOUND; /* Use LUB */
 	}
 
+	if (devfreq->profile->get_cur_freq)
+		devfreq->profile->get_cur_freq(devfreq->dev.parent, &cur_freq);
+	else
+		cur_freq = devfreq->previous_freq;
+
+	freqs.old = cur_freq;
+	freqs.new = freq;
+	devfreq_notify_transition(devfreq, &freqs, DEVFREQ_PRECHANGE);
+
 	err = devfreq->profile->target(devfreq->dev.parent, &freq, flags);
 	if (err)
 		return err;
 
+	freqs.new = freq;
+	devfreq_notify_transition(devfreq, &freqs, DEVFREQ_POSTCHANGE);
+
 	if (devfreq->profile->freq_table)
 		if (devfreq_update_status(devfreq, freq))
 			dev_err(&devfreq->dev,
@@ -541,6 +578,8 @@ struct devfreq *devfreq_add_device(struct device *dev,
 		goto err_out;
 	}
 
+	srcu_init_notifier_head(&devfreq->transition_notifier_list);
+
 	mutex_unlock(&devfreq->lock);
 
 	mutex_lock(&devfreq_list_lock);
@@ -639,6 +678,49 @@ struct devfreq *devm_devfreq_add_device(struct device *dev,
 }
 EXPORT_SYMBOL(devm_devfreq_add_device);
 
+#ifdef CONFIG_OF
+/*
+ * devfreq_get_devfreq_by_phandle - Get the devfreq device from devicetree
+ * @dev - instance to the given device
+ * @index - index into list of devfreq
+ *
+ * return the instance of devfreq device
+ */
+struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev, int index)
+{
+	struct device_node *node;
+	struct devfreq *devfreq;
+
+	if (!dev)
+		return ERR_PTR(-EINVAL);
+
+	if (!dev->of_node)
+		return ERR_PTR(-EINVAL);
+
+	node = of_parse_phandle(dev->of_node, "devfreq", index);
+	if (!node)
+		return ERR_PTR(-ENODEV);
+
+	mutex_lock(&devfreq_list_lock);
+	list_for_each_entry(devfreq, &devfreq_list, node) {
+		if (devfreq->dev.parent
+			&& devfreq->dev.parent->of_node == node) {
+			mutex_unlock(&devfreq_list_lock);
+			return devfreq;
+		}
+	}
+	mutex_unlock(&devfreq_list_lock);
+
+	return ERR_PTR(-EPROBE_DEFER);
+}
+#else
+struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev, int index)
+{
+	return ERR_PTR(-ENODEV);
+}
+#endif /* CONFIG_OF */
+EXPORT_SYMBOL_GPL(devfreq_get_devfreq_by_phandle);
+
 /**
  * devm_devfreq_remove_device() - Resource-managed devfreq_remove_device()
  * @dev:	the device to add devfreq feature.
@@ -1266,6 +1348,129 @@ void devm_devfreq_unregister_opp_notifier(struct device *dev,
 }
 EXPORT_SYMBOL(devm_devfreq_unregister_opp_notifier);
 
+/**
+ * devfreq_register_notifier() - Register a driver with devfreq
+ * @devfreq:	The devfreq object.
+ * @nb:		The notifier block to register.
+ * @list:	DEVFREQ_TRANSITION_NOTIFIER.
+ */
+int devfreq_register_notifier(struct devfreq *devfreq,
+				struct notifier_block *nb,
+				unsigned int list)
+{
+	int ret = 0;
+
+	if (!devfreq)
+		return -EINVAL;
+
+	switch (list) {
+	case DEVFREQ_TRANSITION_NOTIFIER:
+		ret = srcu_notifier_chain_register(
+				&devfreq->transition_notifier_list, nb);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(devfreq_register_notifier);
+
+/*
+ * devfreq_unregister_notifier() - Unregister a driver with devfreq
+ * @devfreq:	The devfreq object.
+ * @nb:		The notifier block to be unregistered.
+ * @list:	DEVFREQ_TRANSITION_NOTIFIER.
+ */
+int devfreq_unregister_notifier(struct devfreq *devfreq,
+				struct notifier_block *nb,
+				unsigned int list)
+{
+	int ret = 0;
+
+	if (!devfreq)
+		return -EINVAL;
+
+	switch (list) {
+	case DEVFREQ_TRANSITION_NOTIFIER:
+		ret = srcu_notifier_chain_unregister(
+				&devfreq->transition_notifier_list, nb);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(devfreq_unregister_notifier);
+
+struct devfreq_notifier_devres {
+	struct devfreq *devfreq;
+	struct notifier_block *nb;
+	unsigned int list;
+};
+
+static void devm_devfreq_notifier_release(struct device *dev, void *res)
+{
+	struct devfreq_notifier_devres *this = res;
+
+	devfreq_unregister_notifier(this->devfreq, this->nb, this->list);
+}
+
+/**
+ * devm_devfreq_register_notifier()
+	- Resource-managed devfreq_register_notifier()
+ * @dev:	The devfreq user device. (parent of devfreq)
+ * @devfreq:	The devfreq object.
+ * @nb:		The notifier block to be unregistered.
+ * @list:	DEVFREQ_TRANSITION_NOTIFIER.
+ */
+int devm_devfreq_register_notifier(struct device *dev,
+				struct devfreq *devfreq,
+				struct notifier_block *nb,
+				unsigned int list)
+{
+	struct devfreq_notifier_devres *ptr;
+	int ret;
+
+	ptr = devres_alloc(devm_devfreq_notifier_release, sizeof(*ptr),
+				GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	ret = devfreq_register_notifier(devfreq, nb, list);
+	if (ret) {
+		devres_free(ptr);
+		return ret;
+	}
+
+	ptr->devfreq = devfreq;
+	ptr->nb = nb;
+	ptr->list = list;
+	devres_add(dev, ptr);
+
+	return 0;
+}
+EXPORT_SYMBOL(devm_devfreq_register_notifier);
+
+/**
+ * devm_devfreq_unregister_notifier()
+	- Resource-managed devfreq_unregister_notifier()
+ * @dev:	The devfreq user device. (parent of devfreq)
+ * @devfreq:	The devfreq object.
+ * @nb:		The notifier block to be unregistered.
+ * @list:	DEVFREQ_TRANSITION_NOTIFIER.
+ */
+void devm_devfreq_unregister_notifier(struct device *dev,
+				struct devfreq *devfreq,
+				struct notifier_block *nb,
+				unsigned int list)
+{
+	WARN_ON(devres_release(dev, devm_devfreq_notifier_release,
+			       devm_devfreq_dev_match, devfreq));
+}
+EXPORT_SYMBOL(devm_devfreq_unregister_notifier);
+
 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 MODULE_DESCRIPTION("devfreq class support");
 MODULE_LICENSE("GPL");

drivers/devfreq/event/Kconfig

@@ -13,6 +13,14 @@ menuconfig PM_DEVFREQ_EVENT
 
 if PM_DEVFREQ_EVENT
 
+config DEVFREQ_EVENT_EXYNOS_NOCP
+	bool "EXYNOS NoC (Network On Chip) Probe DEVFREQ event Driver"
+	depends on ARCH_EXYNOS
+	select PM_OPP
+	help
+	  This add the devfreq-event driver for Exynos SoC. It provides NoC
+	  (Network on Chip) Probe counters to measure the bandwidth of AXI bus.
+
 config DEVFREQ_EVENT_EXYNOS_PPMU
 	bool "EXYNOS PPMU (Platform Performance Monitoring Unit) DEVFREQ event Driver"
 	depends on ARCH_EXYNOS

drivers/devfreq/event/Makefile

 # Exynos DEVFREQ Event Drivers
+
+obj-$(CONFIG_DEVFREQ_EVENT_EXYNOS_NOCP) += exynos-nocp.o
 obj-$(CONFIG_DEVFREQ_EVENT_EXYNOS_PPMU) += exynos-ppmu.o

drivers/devfreq/event/exynos-nocp.c

+/*
+ * exynos-nocp.c - EXYNOS NoC (Network On Chip) Probe support
+ *
+ * Copyright (c) 2016 Samsung Electronics Co., Ltd.
+ * Author : Chanwoo Choi <cw00.choi@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/devfreq-event.h>
+#include <linux/kernel.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "exynos-nocp.h"
+
+struct exynos_nocp {
+	struct devfreq_event_dev *edev;
+	struct devfreq_event_desc desc;
+
+	struct device *dev;
+
+	struct regmap *regmap;
+	struct clk *clk;
+};
+
+/*
+ * The devfreq-event ops structure for nocp probe.
+ */
+static int exynos_nocp_set_event(struct devfreq_event_dev *edev)
+{
+	struct exynos_nocp *nocp = devfreq_event_get_drvdata(edev);
+	int ret;
+
+	/* Disable NoC probe */
+	ret = regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
+				NOCP_MAIN_CTL_STATEN_MASK, 0);
+	if (ret < 0) {
+		dev_err(nocp->dev, "failed to disable the NoC probe device\n");
+		return ret;
+	}
+
+	/* Set a statistics dump period to 0 */
+	ret = regmap_write(nocp->regmap, NOCP_STAT_PERIOD, 0x0);
+	if (ret < 0)
+		goto out;
+
+	/* Set the IntEvent fields of *_SRC */
+	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_0_SRC,
+				NOCP_CNT_SRC_INTEVENT_MASK,
+				NOCP_CNT_SRC_INTEVENT_BYTE_MASK);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_1_SRC,
+				NOCP_CNT_SRC_INTEVENT_MASK,
+				NOCP_CNT_SRC_INTEVENT_CHAIN_MASK);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_2_SRC,
+				NOCP_CNT_SRC_INTEVENT_MASK,
+				NOCP_CNT_SRC_INTEVENT_CYCLE_MASK);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_3_SRC,
+				NOCP_CNT_SRC_INTEVENT_MASK,
+				NOCP_CNT_SRC_INTEVENT_CHAIN_MASK);
+	if (ret < 0)
+		goto out;
+
+
+	/* Set an alarm with a max/min value of 0 to generate StatALARM */
+	ret = regmap_write(nocp->regmap, NOCP_STAT_ALARM_MIN, 0x0);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_write(nocp->regmap, NOCP_STAT_ALARM_MAX, 0x0);
+	if (ret < 0)
+		goto out;
+
+	/* Set AlarmMode */
+	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_0_ALARM_MODE,
+				NOCP_CNT_ALARM_MODE_MASK,
+				NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_1_ALARM_MODE,
+				NOCP_CNT_ALARM_MODE_MASK,
+				NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_2_ALARM_MODE,
+				NOCP_CNT_ALARM_MODE_MASK,
+				NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_update_bits(nocp->regmap, NOCP_COUNTERS_3_ALARM_MODE,
+				NOCP_CNT_ALARM_MODE_MASK,
+				NOCP_CNT_ALARM_MODE_MIN_MAX_MASK);
+	if (ret < 0)
+		goto out;
+
+	/* Enable the measurements by setting AlarmEn and StatEn */
+	ret = regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
+			NOCP_MAIN_CTL_STATEN_MASK | NOCP_MAIN_CTL_ALARMEN_MASK,
+			NOCP_MAIN_CTL_STATEN_MASK | NOCP_MAIN_CTL_ALARMEN_MASK);
+	if (ret < 0)
+		goto out;
+
+	/* Set GlobalEN */
+	ret = regmap_update_bits(nocp->regmap, NOCP_CFG_CTL,
+				NOCP_CFG_CTL_GLOBALEN_MASK,
+				NOCP_CFG_CTL_GLOBALEN_MASK);
+	if (ret < 0)
+		goto out;
+
+	/* Enable NoC probe */
+	ret = regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
+				NOCP_MAIN_CTL_STATEN_MASK,
+				NOCP_MAIN_CTL_STATEN_MASK);
+	if (ret < 0)
+		goto out;
+
+	return 0;
+
+out:
+	/* Reset NoC probe */
+	if (regmap_update_bits(nocp->regmap, NOCP_MAIN_CTL,
+				NOCP_MAIN_CTL_STATEN_MASK, 0)) {
+		dev_err(nocp->dev, "Failed to reset NoC probe device\n");
+	}
+
+	return ret;
+}
+
+static int exynos_nocp_get_event(struct devfreq_event_dev *edev,
+				struct devfreq_event_data *edata)
+{
+	struct exynos_nocp *nocp = devfreq_event_get_drvdata(edev);
+	unsigned int counter[4];
+	int ret;
+
+	/* Read cycle count */
+	ret = regmap_read(nocp->regmap, NOCP_COUNTERS_0_VAL, &counter[0]);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_read(nocp->regmap, NOCP_COUNTERS_1_VAL, &counter[1]);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_read(nocp->regmap, NOCP_COUNTERS_2_VAL, &counter[2]);
+	if (ret < 0)
+		goto out;
+
+	ret = regmap_read(nocp->regmap, NOCP_COUNTERS_3_VAL, &counter[3]);
+	if (ret < 0)
+		goto out;
+
+	edata->load_count = ((counter[1] << 16) | counter[0]);
+	edata->total_count = ((counter[3] << 16) | counter[2]);
+
+	dev_dbg(&edev->dev, "%s (event: %ld/%ld)\n", edev->desc->name,
+					edata->load_count, edata->total_count);
+
+	return 0;
+
+out:
+	edata->load_count = 0;
+	edata->total_count = 0;
+
+	dev_err(nocp->dev, "Failed to read the counter of NoC probe device\n");
+
+	return ret;
+}
+
+static const struct devfreq_event_ops exynos_nocp_ops = {
+	.set_event = exynos_nocp_set_event,
+	.get_event = exynos_nocp_get_event,
+};
+
+static const struct of_device_id exynos_nocp_id_match[] = {
+	{ .compatible = "samsung,exynos5420-nocp", },
+	{ /* sentinel */ },
+};
+
+static struct regmap_config exynos_nocp_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = NOCP_COUNTERS_3_VAL,
+};
+
+static int exynos_nocp_parse_dt(struct platform_device *pdev,
+				struct exynos_nocp *nocp)
+{
+	struct device *dev = nocp->dev;
+	struct device_node *np = dev->of_node;
+	struct resource *res;
+	void __iomem *base;
+
+	if (!np) {
+		dev_err(dev, "failed to find devicetree node\n");
+		return -EINVAL;
+	}
+
+	nocp->clk = devm_clk_get(dev, "nocp");
+	if (IS_ERR(nocp->clk))
+		nocp->clk = NULL;
+
+	/* Maps the memory mapped IO to control nocp register */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (IS_ERR(res))
+		return PTR_ERR(res);
+
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	exynos_nocp_regmap_config.max_register = resource_size(res) - 4;
+
+	nocp->regmap = devm_regmap_init_mmio(dev, base,
+					&exynos_nocp_regmap_config);
+	if (IS_ERR(nocp->regmap)) {
+		dev_err(dev, "failed to initialize regmap\n");
+		return PTR_ERR(nocp->regmap);
+	}
+
+	return 0;
+}
+
+static int exynos_nocp_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct exynos_nocp *nocp;
+	int ret;
+
+	nocp = devm_kzalloc(&pdev->dev, sizeof(*nocp), GFP_KERNEL);
+	if (!nocp)
+		return -ENOMEM;
+
+	nocp->dev = &pdev->dev;
+
+	/* Parse dt data to get resource */
+	ret = exynos_nocp_parse_dt(pdev, nocp);
+	if (ret < 0) {
+		dev_err(&pdev->dev,
+			"failed to parse devicetree for resource\n");
+		return ret;
+	}
+
+	/* Add devfreq-event device to measure the bandwidth of NoC */
+	nocp->desc.ops = &exynos_nocp_ops;
+	nocp->desc.driver_data = nocp;
+	nocp->desc.name = np->full_name;
+	nocp->edev = devm_devfreq_event_add_edev(&pdev->dev, &nocp->desc);
+	if (IS_ERR(nocp->edev)) {
+		dev_err(&pdev->dev,
+			"failed to add devfreq-event device\n");
+		return PTR_ERR(nocp->edev);
+	}
+	platform_set_drvdata(pdev, nocp);
+
+	clk_prepare_enable(nocp->clk);
+
+	pr_info("exynos-nocp: new NoC Probe device registered: %s\n",
+			dev_name(dev));
+
+	return 0;
+}
+
+static int exynos_nocp_remove(struct platform_device *pdev)
+{
+	struct exynos_nocp *nocp = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(nocp->clk);
+
+	return 0;
+}
+
+static struct platform_driver exynos_nocp_driver = {
+	.probe	= exynos_nocp_probe,
+	.remove	= exynos_nocp_remove,
+	.driver = {
+		.name	= "exynos-nocp",
+		.of_match_table = exynos_nocp_id_match,
+	},
+};
+module_platform_driver(exynos_nocp_driver);
+
+MODULE_DESCRIPTION("Exynos NoC (Network on Chip) Probe driver");
+MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
+MODULE_LICENSE("GPL");

drivers/devfreq/event/exynos-nocp.h

+/*
+ * exynos-nocp.h - EXYNOS NoC (Network on Chip) Probe header file
+ *
+ * Copyright (c) 2016 Samsung Electronics Co., Ltd.
+ * Author : Chanwoo Choi <cw00.choi@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __EXYNOS_NOCP_H__
+#define __EXYNOS_NOCP_H__
+
+enum nocp_reg {
+	NOCP_ID_REVISION_ID		= 0x04,
+	NOCP_MAIN_CTL			= 0x08,
+	NOCP_CFG_CTL			= 0x0C,
+
+	NOCP_STAT_PERIOD		= 0x24,
+	NOCP_STAT_GO			= 0x28,
+	NOCP_STAT_ALARM_MIN		= 0x2C,
+	NOCP_STAT_ALARM_MAX		= 0x30,
+	NOCP_STAT_ALARM_STATUS		= 0x34,
+	NOCP_STAT_ALARM_CLR		= 0x38,
+
+	NOCP_COUNTERS_0_SRC		= 0x138,
+	NOCP_COUNTERS_0_ALARM_MODE	= 0x13C,
+	NOCP_COUNTERS_0_VAL		= 0x140,
+
+	NOCP_COUNTERS_1_SRC		= 0x14C,
+	NOCP_COUNTERS_1_ALARM_MODE	= 0x150,
+	NOCP_COUNTERS_1_VAL		= 0x154,
+
+	NOCP_COUNTERS_2_SRC		= 0x160,
+	NOCP_COUNTERS_2_ALARM_MODE	= 0x164,
+	NOCP_COUNTERS_2_VAL		= 0x168,
+
+	NOCP_COUNTERS_3_SRC		= 0x174,
+	NOCP_COUNTERS_3_ALARM_MODE	= 0x178,
+	NOCP_COUNTERS_3_VAL		= 0x17C,
+};
+
+/* NOCP_MAIN_CTL register */
+#define NOCP_MAIN_CTL_ERREN_MASK		BIT(0)
+#define NOCP_MAIN_CTL_TRACEEN_MASK		BIT(1)
+#define NOCP_MAIN_CTL_PAYLOADEN_MASK		BIT(2)
+#define NOCP_MAIN_CTL_STATEN_MASK		BIT(3)
+#define NOCP_MAIN_CTL_ALARMEN_MASK		BIT(4)
+#define NOCP_MAIN_CTL_STATCONDDUMP_MASK	BIT(5)
+#define NOCP_MAIN_CTL_INTRUSIVEMODE_MASK	BIT(6)
+
+/* NOCP_CFG_CTL register */
+#define NOCP_CFG_CTL_GLOBALEN_MASK		BIT(0)
+#define NOCP_CFG_CTL_ACTIVE_MASK		BIT(1)
+
+/* NOCP_COUNTERS_x_SRC register */
+#define NOCP_CNT_SRC_INTEVENT_SHIFT		0
+#define NOCP_CNT_SRC_INTEVENT_MASK		(0x1F << NOCP_CNT_SRC_INTEVENT_SHIFT)
+#define NOCP_CNT_SRC_INTEVENT_OFF_MASK		(0x0 << NOCP_CNT_SRC_INTEVENT_SHIFT)
+#define NOCP_CNT_SRC_INTEVENT_CYCLE_MASK	(0x1 << NOCP_CNT_SRC_INTEVENT_SHIFT)
+#define NOCP_CNT_SRC_INTEVENT_IDLE_MASK		(0x2 << NOCP_CNT_SRC_INTEVENT_SHIFT)
+#define NOCP_CNT_SRC_INTEVENT_XFER_MASK		(0x3 << NOCP_CNT_SRC_INTEVENT_SHIFT)
+#define NOCP_CNT_SRC_INTEVENT_BUSY_MASK		(0x4 << NOCP_CNT_SRC_INTEVENT_SHIFT)
+#define NOCP_CNT_SRC_INTEVENT_WAIT_MASK		(0x5 << NOCP_CNT_SRC_INTEVENT_SHIFT)
+#define NOCP_CNT_SRC_INTEVENT_PKT_MASK		(0x6 << NOCP_CNT_SRC_INTEVENT_SHIFT)
+#define NOCP_CNT_SRC_INTEVENT_BYTE_MASK		(0x8 << NOCP_CNT_SRC_INTEVENT_SHIFT)
+#define NOCP_CNT_SRC_INTEVENT_CHAIN_MASK	(0x10 << NOCP_CNT_SRC_INTEVENT_SHIFT)
+
+/* NOCP_COUNTERS_x_ALARM_MODE register */
+#define NOCP_CNT_ALARM_MODE_SHIFT		0
+#define NOCP_CNT_ALARM_MODE_MASK		(0x3 << NOCP_CNT_ALARM_MODE_SHIFT)
+#define NOCP_CNT_ALARM_MODE_OFF_MASK		(0x0 << NOCP_CNT_ALARM_MODE_SHIFT)
+#define NOCP_CNT_ALARM_MODE_MIN_MASK		(0x1 << NOCP_CNT_ALARM_MODE_SHIFT)
+#define NOCP_CNT_ALARM_MODE_MAX_MASK		(0x2 << NOCP_CNT_ALARM_MODE_SHIFT)
+#define NOCP_CNT_ALARM_MODE_MIN_MAX_MASK	(0x3 << NOCP_CNT_ALARM_MODE_SHIFT)
+
+#endif /* __EXYNOS_NOCP_H__ */

drivers/devfreq/exynos-bus.c

+/*
+ * Generic Exynos Bus frequency driver with DEVFREQ Framework
+ *
+ * Copyright (c) 2016 Samsung Electronics Co., Ltd.
+ * Author : Chanwoo Choi <cw00.choi@samsung.com>
+ *
+ * This driver support Exynos Bus frequency feature by using
+ * DEVFREQ framework and is based on drivers/devfreq/exynos/exynos4_bus.c.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/devfreq.h>
+#include <linux/devfreq-event.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/pm_opp.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+#define DEFAULT_SATURATION_RATIO	40
+#define DEFAULT_VOLTAGE_TOLERANCE	2
+
+struct exynos_bus {
+	struct device *dev;
+
+	struct devfreq *devfreq;
+	struct devfreq_event_dev **edev;
+	unsigned int edev_count;
+	struct mutex lock;
+
+	struct dev_pm_opp *curr_opp;
+
+	struct regulator *regulator;
+	struct clk *clk;
+	unsigned int voltage_tolerance;
+	unsigned int ratio;
+};
+
+/*
+ * Control the devfreq-event device to get the current state of bus
+ */
+#define exynos_bus_ops_edev(ops)				\
+static int exynos_bus_##ops(struct exynos_bus *bus)		\
+{								\
+	int i, ret;						\
+								\
+	for (i = 0; i < bus->edev_count; i++) {			\
+		if (!bus->edev[i])				\
+			continue;				\
+		ret = devfreq_event_##ops(bus->edev[i]);	\
+		if (ret < 0)					\
+			return ret;				\
+	}							\
+								\
+	return 0;						\
+}
+exynos_bus_ops_edev(enable_edev);
+exynos_bus_ops_edev(disable_edev);
+exynos_bus_ops_edev(set_event);
+
+static int exynos_bus_get_event(struct exynos_bus *bus,
+				struct devfreq_event_data *edata)
+{
+	struct devfreq_event_data event_data;
+	unsigned long load_count = 0, total_count = 0;
+	int i, ret = 0;
+
+	for (i = 0; i < bus->edev_count; i++) {
+		if (!bus->edev[i])
+			continue;
+
+		ret = devfreq_event_get_event(bus->edev[i], &event_data);
+		if (ret < 0)
+			return ret;
+
+		if (i == 0 || event_data.load_count > load_count) {
+			load_count = event_data.load_count;
+			total_count = event_data.total_count;
+		}
+	}
+
+	edata->load_count = load_count;
+	edata->total_count = total_count;
+
+	return ret;
+}
+
+/*
+ * Must necessary function for devfreq simple-ondemand governor
+ */
+static int exynos_bus_target(struct device *dev, unsigned long *freq, u32 flags)
+{
+	struct exynos_bus *bus = dev_get_drvdata(dev);
+	struct dev_pm_opp *new_opp;
+	unsigned long old_freq, new_freq, old_volt, new_volt, tol;
+	int ret = 0;
+
+	/* Get new opp-bus instance according to new bus clock */
+	rcu_read_lock();
+	new_opp = devfreq_recommended_opp(dev, freq, flags);
+	if (IS_ERR(new_opp)) {
+		dev_err(dev, "failed to get recommended opp instance\n");
+		rcu_read_unlock();
+		return PTR_ERR(new_opp);
+	}
+
+	new_freq = dev_pm_opp_get_freq(new_opp);
+	new_volt = dev_pm_opp_get_voltage(new_opp);
+	old_freq = dev_pm_opp_get_freq(bus->curr_opp);
+	old_volt = dev_pm_opp_get_voltage(bus->curr_opp);
+	rcu_read_unlock();
+
+	if (old_freq == new_freq)
+		return 0;
+	tol = new_volt * bus->voltage_tolerance / 100;
+
+	/* Change voltage and frequency according to new OPP level */
+	mutex_lock(&bus->lock);
+
+	if (old_freq < new_freq) {
+		ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol);
+		if (ret < 0) {
+			dev_err(bus->dev, "failed to set voltage\n");
+			goto out;
+		}
+	}
+
+	ret = clk_set_rate(bus->clk, new_freq);
+	if (ret < 0) {
+		dev_err(dev, "failed to change clock of bus\n");
+		clk_set_rate(bus->clk, old_freq);
+		goto out;
+	}
+
+	if (old_freq > new_freq) {
+		ret = regulator_set_voltage_tol(bus->regulator, new_volt, tol);
+		if (ret < 0) {
+			dev_err(bus->dev, "failed to set voltage\n");
+			goto out;
+		}
+	}
+	bus->curr_opp = new_opp;
+
+	dev_dbg(dev, "Set the frequency of bus (%lukHz -> %lukHz)\n",
+			old_freq/1000, new_freq/1000);
+out:
+	mutex_unlock(&bus->lock);
+
+	return ret;
+}
+
+static int exynos_bus_get_dev_status(struct device *dev,
+				     struct devfreq_dev_status *stat)
+{
+	struct exynos_bus *bus = dev_get_drvdata(dev);
+	struct devfreq_event_data edata;
+	int ret;
+
+	rcu_read_lock();
+	stat->current_frequency = dev_pm_opp_get_freq(bus->curr_opp);
+	rcu_read_unlock();
+
+	ret = exynos_bus_get_event(bus, &edata);
+	if (ret < 0) {
+		stat->total_time = stat->busy_time = 0;
+		goto err;
+	}
+
+	stat->busy_time = (edata.load_count * 100) / bus->ratio;
+	stat->total_time = edata.total_count;
+
+	dev_dbg(dev, "Usage of devfreq-event : %lu/%lu\n", stat->busy_time,
+							stat->total_time);
+
+err:
+	ret = exynos_bus_set_event(bus);
+	if (ret < 0) {
+		dev_err(dev, "failed to set event to devfreq-event devices\n");
+		return ret;
+	}
+
+	return ret;
+}
+
+static void exynos_bus_exit(struct device *dev)
+{
+	struct exynos_bus *bus = dev_get_drvdata(dev);
+	int ret;
+
+	ret = exynos_bus_disable_edev(bus);
+	if (ret < 0)
+		dev_warn(dev, "failed to disable the devfreq-event devices\n");
+
+	if (bus->regulator)
+		regulator_disable(bus->regulator);
+
+	dev_pm_opp_of_remove_table(dev);
+	clk_disable_unprepare(bus->clk);
+}
+
+/*
+ * Must necessary function for devfreq passive governor
+ */
+static int exynos_bus_passive_target(struct device *dev, unsigned long *freq,
+					u32 flags)
+{
+	struct exynos_bus *bus = dev_get_drvdata(dev);
+	struct dev_pm_opp *new_opp;
+	unsigned long old_freq, new_freq;
+	int ret = 0;
+
+	/* Get new opp-bus instance according to new bus clock */
+	rcu_read_lock();
+	new_opp = devfreq_recommended_opp(dev, freq, flags);
+	if (IS_ERR(new_opp)) {
+		dev_err(dev, "failed to get recommended opp instance\n");
+		rcu_read_unlock();
+		return PTR_ERR(new_opp);
+	}
+
+	new_freq = dev_pm_opp_get_freq(new_opp);
+	old_freq = dev_pm_opp_get_freq(bus->curr_opp);
+	rcu_read_unlock();
+
+	if (old_freq == new_freq)
+		return 0;
+
+	/* Change the frequency according to new OPP level */
+	mutex_lock(&bus->lock);
+
+	ret = clk_set_rate(bus->clk, new_freq);
+	if (ret < 0) {
+		dev_err(dev, "failed to set the clock of bus\n");
+		goto out;
+	}
+
+	*freq = new_freq;
+	bus->curr_opp = new_opp;
+
+	dev_dbg(dev, "Set the frequency of bus (%lukHz -> %lukHz)\n",
+			old_freq/1000, new_freq/1000);
+out:
+	mutex_unlock(&bus->lock);
+
+	return ret;
+}
+
+static void exynos_bus_passive_exit(struct device *dev)
+{
+	struct exynos_bus *bus = dev_get_drvdata(dev);
+
+	dev_pm_opp_of_remove_table(dev);
+	clk_disable_unprepare(bus->clk);
+}
+
+static int exynos_bus_parent_parse_of(struct device_node *np,
+					struct exynos_bus *bus)
+{
+	struct device *dev = bus->dev;
+	int i, ret, count, size;
+
+	/* Get the regulator to provide each bus with the power */
+	bus->regulator = devm_regulator_get(dev, "vdd");
+	if (IS_ERR(bus->regulator)) {
+		dev_err(dev, "failed to get VDD regulator\n");
+		return PTR_ERR(bus->regulator);
+	}
+
+	ret = regulator_enable(bus->regulator);
+	if (ret < 0) {
+		dev_err(dev, "failed to enable VDD regulator\n");
+		return ret;
+	}
+
+	/*
+	 * Get the devfreq-event devices to get the current utilization of
+	 * buses. This raw data will be used in devfreq ondemand governor.
+	 */
+	count = devfreq_event_get_edev_count(dev);
+	if (count < 0) {
+		dev_err(dev, "failed to get the count of devfreq-event dev\n");
+		ret = count;
+		goto err_regulator;
+	}
+	bus->edev_count = count;
+
+	size = sizeof(*bus->edev) * count;
+	bus->edev = devm_kzalloc(dev, size, GFP_KERNEL);
+	if (!bus->edev) {
+		ret = -ENOMEM;
+		goto err_regulator;
+	}
+
+	for (i = 0; i < count; i++) {
+		bus->edev[i] = devfreq_event_get_edev_by_phandle(dev, i);
+		if (IS_ERR(bus->edev[i])) {
+			ret = -EPROBE_DEFER;
+			goto err_regulator;
+		}
+	}
+
+	/*
+	 * Optionally, Get the saturation ratio according to Exynos SoC
+	 * When measuring the utilization of each AXI bus with devfreq-event
+	 * devices, the measured real cycle might be much lower than the
+	 * total cycle of bus during sampling rate. In result, the devfreq
+	 * simple-ondemand governor might not decide to change the current
+	 * frequency due to too utilization (= real cycle/total cycle).
+	 * So, this property is used to adjust the utilization when calculating
+	 * the busy_time in exynos_bus_get_dev_status().
+	 */
+	if (of_property_read_u32(np, "exynos,saturation-ratio", &bus->ratio))
+		bus->ratio = DEFAULT_SATURATION_RATIO;
+
+	if (of_property_read_u32(np, "exynos,voltage-tolerance",
+					&bus->voltage_tolerance))
+		bus->voltage_tolerance = DEFAULT_VOLTAGE_TOLERANCE;
+
+	return 0;
+
+err_regulator:
+	regulator_disable(bus->regulator);
+
+	return ret;
+}
+
+static int exynos_bus_parse_of(struct device_node *np,
+			      struct exynos_bus *bus)
+{
+	struct device *dev = bus->dev;
+	unsigned long rate;
+	int ret;
+
+	/* Get the clock to provide each bus with source clock */
+	bus->clk = devm_clk_get(dev, "bus");
+	if (IS_ERR(bus->clk)) {
+		dev_err(dev, "failed to get bus clock\n");
+		return PTR_ERR(bus->clk);
+	}
+
+	ret = clk_prepare_enable(bus->clk);
+	if (ret < 0) {
+		dev_err(dev, "failed to get enable clock\n");
+		return ret;
+	}
+
+	/* Get the freq and voltage from OPP table to scale the bus freq */
+	rcu_read_lock();
+	ret = dev_pm_opp_of_add_table(dev);
+	if (ret < 0) {
+		dev_err(dev, "failed to get OPP table\n");
+		rcu_read_unlock();
+		goto err_clk;
+	}
+
+	rate = clk_get_rate(bus->clk);
+	bus->curr_opp = devfreq_recommended_opp(dev, &rate, 0);
+	if (IS_ERR(bus->curr_opp)) {
+		dev_err(dev, "failed to find dev_pm_opp\n");
+		rcu_read_unlock();
+		ret = PTR_ERR(bus->curr_opp);
+		goto err_opp;
+	}
+	rcu_read_unlock();
+
+	return 0;
+
+err_opp:
+	dev_pm_opp_of_remove_table(dev);
+err_clk:
+	clk_disable_unprepare(bus->clk);
+
+	return ret;
+}
+
+static int exynos_bus_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct devfreq_dev_profile *profile;
+	struct devfreq_simple_ondemand_data *ondemand_data;
+	struct devfreq_passive_data *passive_data;
+	struct devfreq *parent_devfreq;
+	struct exynos_bus *bus;
+	int ret, max_state;
+	unsigned long min_freq, max_freq;
+
+	if (!np) {
+		dev_err(dev, "failed to find devicetree node\n");
+		return -EINVAL;
+	}
+
+	bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
+	if (!bus)
+		return -ENOMEM;
+	mutex_init(&bus->lock);
+	bus->dev = &pdev->dev;
+	platform_set_drvdata(pdev, bus);
+
+	/* Parse the device-tree to get the resource information */
+	ret = exynos_bus_parse_of(np, bus);
+	if (ret < 0)
+		goto err;
+
+	profile = devm_kzalloc(dev, sizeof(*profile), GFP_KERNEL);
+	if (!profile) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	if (of_parse_phandle(dev->of_node, "devfreq", 0))
+		goto passive;
+	else
+		ret = exynos_bus_parent_parse_of(np, bus);
+
+	if (ret < 0)
+		goto err;
+
+	/* Initialize the struct profile and governor data for parent device */
+	profile->polling_ms = 50;
+	profile->target = exynos_bus_target;
+	profile->get_dev_status = exynos_bus_get_dev_status;
+	profile->exit = exynos_bus_exit;
+
+	ondemand_data = devm_kzalloc(dev, sizeof(*ondemand_data), GFP_KERNEL);
+	if (!ondemand_data) {
+		ret = -ENOMEM;
+		goto err;
+	}
+	ondemand_data->upthreshold = 40;
+	ondemand_data->downdifferential = 5;
+
+	/* Add devfreq device to monitor and handle the exynos bus */
+	bus->devfreq = devm_devfreq_add_device(dev, profile, "simple_ondemand",
+						ondemand_data);
+	if (IS_ERR(bus->devfreq)) {
+		dev_err(dev, "failed to add devfreq device\n");
+		ret = PTR_ERR(bus->devfreq);
+		goto err;
+	}
+
+	/* Register opp_notifier to catch the change of OPP  */
+	ret = devm_devfreq_register_opp_notifier(dev, bus->devfreq);
+	if (ret < 0) {
+		dev_err(dev, "failed to register opp notifier\n");
+		goto err;
+	}
+
+	/*
+	 * Enable devfreq-event to get raw data which is used to determine
+	 * current bus load.
+	 */
+	ret = exynos_bus_enable_edev(bus);
+	if (ret < 0) {
+		dev_err(dev, "failed to enable devfreq-event devices\n");
+		goto err;
+	}
+
+	ret = exynos_bus_set_event(bus);
+	if (ret < 0) {
+		dev_err(dev, "failed to set event to devfreq-event devices\n");
+		goto err;
+	}
+
+	goto out;
+passive:
+	/* Initialize the struct profile and governor data for passive device */
+	profile->target = exynos_bus_passive_target;
+	profile->exit = exynos_bus_passive_exit;
+
+	/* Get the instance of parent devfreq device */
+	parent_devfreq = devfreq_get_devfreq_by_phandle(dev, 0);
+	if (IS_ERR(parent_devfreq)) {
+		ret = -EPROBE_DEFER;
+		goto err;
+	}
+
+	passive_data = devm_kzalloc(dev, sizeof(*passive_data), GFP_KERNEL);
+	if (!passive_data) {
+		ret = -ENOMEM;
+		goto err;
+	}
+	passive_data->parent = parent_devfreq;
+
+	/* Add devfreq device for exynos bus with passive governor */
+	bus->devfreq = devm_devfreq_add_device(dev, profile, "passive",
+						passive_data);
+	if (IS_ERR(bus->devfreq)) {
+		dev_err(dev,
+			"failed to add devfreq dev with passive governor\n");
+		ret = -EPROBE_DEFER;
+		goto err;
+	}
+
+out:
+	max_state = bus->devfreq->profile->max_state;
+	min_freq = (bus->devfreq->profile->freq_table[0] / 1000);
+	max_freq = (bus->devfreq->profile->freq_table[max_state - 1] / 1000);
+	pr_info("exynos-bus: new bus device registered: %s (%6ld KHz ~ %6ld KHz)\n",
+			dev_name(dev), min_freq, max_freq);
+
+	return 0;
+
+err:
+	dev_pm_opp_of_remove_table(dev);
+	clk_disable_unprepare(bus->clk);
+
+	return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int exynos_bus_resume(struct device *dev)
+{
+	struct exynos_bus *bus = dev_get_drvdata(dev);
+	int ret;
+
+	ret = exynos_bus_enable_edev(bus);
+	if (ret < 0) {
+		dev_err(dev, "failed to enable the devfreq-event devices\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int exynos_bus_suspend(struct device *dev)
+{
+	struct exynos_bus *bus = dev_get_drvdata(dev);
+	int ret;
+
+	ret = exynos_bus_disable_edev(bus);
+	if (ret < 0) {
+		dev_err(dev, "failed to disable the devfreq-event devices\n");
+		return ret;
+	}
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops exynos_bus_pm = {
+	SET_SYSTEM_SLEEP_PM_OPS(exynos_bus_suspend, exynos_bus_resume)
+};
+
+static const struct of_device_id exynos_bus_of_match[] = {
+	{ .compatible = "samsung,exynos-bus", },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, exynos_bus_of_match);
+
+static struct platform_driver exynos_bus_platdrv = {
+	.probe		= exynos_bus_probe,
+	.driver = {
+		.name	= "exynos-bus",
+		.pm	= &exynos_bus_pm,
+		.of_match_table = of_match_ptr(exynos_bus_of_match),
+	},
+};
+module_platform_driver(exynos_bus_platdrv);
+
+MODULE_DESCRIPTION("Generic Exynos Bus frequency driver");
+MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
+MODULE_LICENSE("GPL v2");

drivers/devfreq/exynos/Makefile

-# Exynos DEVFREQ Drivers
-obj-$(CONFIG_ARM_EXYNOS4_BUS_DEVFREQ)	+= exynos_ppmu.o exynos4_bus.o
-obj-$(CONFIG_ARM_EXYNOS5_BUS_DEVFREQ)	+= exynos_ppmu.o exynos5_bus.o

drivers/devfreq/exynos/exynos4_bus.h

-/*
- * Copyright (c) 2013 Samsung Electronics Co., Ltd.
- *		http://www.samsung.com/
- *
- * EXYNOS4 BUS header
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
-*/
-
-#ifndef __DEVFREQ_EXYNOS4_BUS_H
-#define __DEVFREQ_EXYNOS4_BUS_H __FILE__
-
-#include <mach/map.h>
-
-#define EXYNOS4_CLKDIV_LEFTBUS			(S5P_VA_CMU + 0x04500)
-#define EXYNOS4_CLKDIV_STAT_LEFTBUS		(S5P_VA_CMU + 0x04600)
-
-#define EXYNOS4_CLKDIV_RIGHTBUS			(S5P_VA_CMU + 0x08500)
-#define EXYNOS4_CLKDIV_STAT_RIGHTBUS		(S5P_VA_CMU + 0x08600)
-
-#define EXYNOS4_CLKDIV_TOP			(S5P_VA_CMU + 0x0C510)
-#define EXYNOS4_CLKDIV_CAM			(S5P_VA_CMU + 0x0C520)
-#define EXYNOS4_CLKDIV_MFC			(S5P_VA_CMU + 0x0C528)
-
-#define EXYNOS4_CLKDIV_STAT_TOP			(S5P_VA_CMU + 0x0C610)
-#define EXYNOS4_CLKDIV_STAT_MFC			(S5P_VA_CMU + 0x0C628)
-
-#define EXYNOS4210_CLKGATE_IP_IMAGE		(S5P_VA_CMU + 0x0C930)
-#define EXYNOS4212_CLKGATE_IP_IMAGE		(S5P_VA_CMU + 0x04930)
-
-#define EXYNOS4_CLKDIV_DMC0			(S5P_VA_CMU + 0x10500)
-#define EXYNOS4_CLKDIV_DMC1			(S5P_VA_CMU + 0x10504)
-#define EXYNOS4_CLKDIV_STAT_DMC0		(S5P_VA_CMU + 0x10600)
-#define EXYNOS4_CLKDIV_STAT_DMC1		(S5P_VA_CMU + 0x10604)
-
-#define EXYNOS4_DMC_PAUSE_CTRL			(S5P_VA_CMU + 0x11094)
-#define EXYNOS4_DMC_PAUSE_ENABLE		(1 << 0)
-
-#define EXYNOS4_CLKDIV_DMC0_ACP_SHIFT		(0)
-#define EXYNOS4_CLKDIV_DMC0_ACP_MASK		(0x7 << EXYNOS4_CLKDIV_DMC0_ACP_SHIFT)
-#define EXYNOS4_CLKDIV_DMC0_ACPPCLK_SHIFT	(4)
-#define EXYNOS4_CLKDIV_DMC0_ACPPCLK_MASK	(0x7 << EXYNOS4_CLKDIV_DMC0_ACPPCLK_SHIFT)
-#define EXYNOS4_CLKDIV_DMC0_DPHY_SHIFT		(8)
-#define EXYNOS4_CLKDIV_DMC0_DPHY_MASK		(0x7 << EXYNOS4_CLKDIV_DMC0_DPHY_SHIFT)
-#define EXYNOS4_CLKDIV_DMC0_DMC_SHIFT		(12)
-#define EXYNOS4_CLKDIV_DMC0_DMC_MASK		(0x7 << EXYNOS4_CLKDIV_DMC0_DMC_SHIFT)
-#define EXYNOS4_CLKDIV_DMC0_DMCD_SHIFT		(16)
-#define EXYNOS4_CLKDIV_DMC0_DMCD_MASK		(0x7 << EXYNOS4_CLKDIV_DMC0_DMCD_SHIFT)
-#define EXYNOS4_CLKDIV_DMC0_DMCP_SHIFT		(20)
-#define EXYNOS4_CLKDIV_DMC0_DMCP_MASK		(0x7 << EXYNOS4_CLKDIV_DMC0_DMCP_SHIFT)
-#define EXYNOS4_CLKDIV_DMC0_COPY2_SHIFT		(24)
-#define EXYNOS4_CLKDIV_DMC0_COPY2_MASK		(0x7 << EXYNOS4_CLKDIV_DMC0_COPY2_SHIFT)
-#define EXYNOS4_CLKDIV_DMC0_CORETI_SHIFT	(28)
-#define EXYNOS4_CLKDIV_DMC0_CORETI_MASK		(0x7 << EXYNOS4_CLKDIV_DMC0_CORETI_SHIFT)
-
-#define EXYNOS4_CLKDIV_DMC1_G2D_ACP_SHIFT	(0)
-#define EXYNOS4_CLKDIV_DMC1_G2D_ACP_MASK	(0xf << EXYNOS4_CLKDIV_DMC1_G2D_ACP_SHIFT)
-#define EXYNOS4_CLKDIV_DMC1_C2C_SHIFT		(4)
-#define EXYNOS4_CLKDIV_DMC1_C2C_MASK		(0x7 << EXYNOS4_CLKDIV_DMC1_C2C_SHIFT)
-#define EXYNOS4_CLKDIV_DMC1_PWI_SHIFT		(8)
-#define EXYNOS4_CLKDIV_DMC1_PWI_MASK		(0xf << EXYNOS4_CLKDIV_DMC1_PWI_SHIFT)
-#define EXYNOS4_CLKDIV_DMC1_C2CACLK_SHIFT	(12)
-#define EXYNOS4_CLKDIV_DMC1_C2CACLK_MASK	(0x7 << EXYNOS4_CLKDIV_DMC1_C2CACLK_SHIFT)
-#define EXYNOS4_CLKDIV_DMC1_DVSEM_SHIFT		(16)
-#define EXYNOS4_CLKDIV_DMC1_DVSEM_MASK		(0x7f << EXYNOS4_CLKDIV_DMC1_DVSEM_SHIFT)
-#define EXYNOS4_CLKDIV_DMC1_DPM_SHIFT		(24)
-#define EXYNOS4_CLKDIV_DMC1_DPM_MASK		(0x7f << EXYNOS4_CLKDIV_DMC1_DPM_SHIFT)
-
-#define EXYNOS4_CLKDIV_MFC_SHIFT		(0)
-#define EXYNOS4_CLKDIV_MFC_MASK			(0x7 << EXYNOS4_CLKDIV_MFC_SHIFT)
-
-#define EXYNOS4_CLKDIV_TOP_ACLK200_SHIFT	(0)
-#define EXYNOS4_CLKDIV_TOP_ACLK200_MASK		(0x7 << EXYNOS4_CLKDIV_TOP_ACLK200_SHIFT)
-#define EXYNOS4_CLKDIV_TOP_ACLK100_SHIFT	(4)
-#define EXYNOS4_CLKDIV_TOP_ACLK100_MASK		(0xF << EXYNOS4_CLKDIV_TOP_ACLK100_SHIFT)
-#define EXYNOS4_CLKDIV_TOP_ACLK160_SHIFT	(8)
-#define EXYNOS4_CLKDIV_TOP_ACLK160_MASK		(0x7 << EXYNOS4_CLKDIV_TOP_ACLK160_SHIFT)
-#define EXYNOS4_CLKDIV_TOP_ACLK133_SHIFT	(12)
-#define EXYNOS4_CLKDIV_TOP_ACLK133_MASK		(0x7 << EXYNOS4_CLKDIV_TOP_ACLK133_SHIFT)
-#define EXYNOS4_CLKDIV_TOP_ONENAND_SHIFT	(16)
-#define EXYNOS4_CLKDIV_TOP_ONENAND_MASK		(0x7 << EXYNOS4_CLKDIV_TOP_ONENAND_SHIFT)
-#define EXYNOS4_CLKDIV_TOP_ACLK266_GPS_SHIFT	(20)
-#define EXYNOS4_CLKDIV_TOP_ACLK266_GPS_MASK	(0x7 << EXYNOS4_CLKDIV_TOP_ACLK266_GPS_SHIFT)
-#define EXYNOS4_CLKDIV_TOP_ACLK400_MCUISP_SHIFT	(24)
-#define EXYNOS4_CLKDIV_TOP_ACLK400_MCUISP_MASK	(0x7 << EXYNOS4_CLKDIV_TOP_ACLK400_MCUISP_SHIFT)
-
-#define EXYNOS4_CLKDIV_BUS_GDLR_SHIFT		(0)
-#define EXYNOS4_CLKDIV_BUS_GDLR_MASK		(0x7 << EXYNOS4_CLKDIV_BUS_GDLR_SHIFT)
-#define EXYNOS4_CLKDIV_BUS_GPLR_SHIFT		(4)
-#define EXYNOS4_CLKDIV_BUS_GPLR_MASK		(0x7 << EXYNOS4_CLKDIV_BUS_GPLR_SHIFT)
-
-#define EXYNOS4_CLKDIV_CAM_FIMC0_SHIFT		(0)
-#define EXYNOS4_CLKDIV_CAM_FIMC0_MASK		(0xf << EXYNOS4_CLKDIV_CAM_FIMC0_SHIFT)
-#define EXYNOS4_CLKDIV_CAM_FIMC1_SHIFT		(4)
-#define EXYNOS4_CLKDIV_CAM_FIMC1_MASK		(0xf << EXYNOS4_CLKDIV_CAM_FIMC1_SHIFT)
-#define EXYNOS4_CLKDIV_CAM_FIMC2_SHIFT		(8)
-#define EXYNOS4_CLKDIV_CAM_FIMC2_MASK		(0xf << EXYNOS4_CLKDIV_CAM_FIMC2_SHIFT)
-#define EXYNOS4_CLKDIV_CAM_FIMC3_SHIFT		(12)
-#define EXYNOS4_CLKDIV_CAM_FIMC3_MASK		(0xf << EXYNOS4_CLKDIV_CAM_FIMC3_SHIFT)
-
-#define EXYNOS4_CLKDIV_CAM1			(S5P_VA_CMU + 0x0C568)
-
-#define EXYNOS4_CLKDIV_STAT_CAM1		(S5P_VA_CMU + 0x0C668)
-
-#define EXYNOS4_CLKDIV_CAM1_JPEG_SHIFT		(0)
-#define EXYNOS4_CLKDIV_CAM1_JPEG_MASK		(0xf << EXYNOS4_CLKDIV_CAM1_JPEG_SHIFT)
-
-#endif /* __DEVFREQ_EXYNOS4_BUS_H */

drivers/devfreq/exynos/exynos5_bus.c

-/*
- * Copyright (c) 2012 Samsung Electronics Co., Ltd.
- *		http://www.samsung.com/
- *
- * EXYNOS5 INT clock frequency scaling support using DEVFREQ framework
- * Based on work done by Jonghwan Choi <jhbird.choi@samsung.com>
- * Support for only EXYNOS5250 is present.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- */
-
-#include <linux/module.h>
-#include <linux/devfreq.h>
-#include <linux/io.h>
-#include <linux/pm_opp.h>
-#include <linux/slab.h>
-#include <linux/suspend.h>
-#include <linux/clk.h>
-#include <linux/delay.h>
-#include <linux/platform_device.h>
-#include <linux/pm_qos.h>
-#include <linux/regulator/consumer.h>
-#include <linux/of_address.h>
-#include <linux/of_platform.h>
-
-#include "exynos_ppmu.h"
-
-#define MAX_SAFEVOLT			1100000 /* 1.10V */
-/* Assume that the bus is saturated if the utilization is 25% */
-#define INT_BUS_SATURATION_RATIO	25
-
-enum int_level_idx {
-	LV_0,
-	LV_1,
-	LV_2,
-	LV_3,
-	LV_4,
-	_LV_END
-};
-
-enum exynos_ppmu_list {
-	PPMU_RIGHT,
-	PPMU_END,
-};
-
-struct busfreq_data_int {
-	struct device *dev;
-	struct devfreq *devfreq;
-	struct regulator *vdd_int;
-	struct busfreq_ppmu_data ppmu_data;
-	unsigned long curr_freq;
-	bool disabled;
-
-	struct notifier_block pm_notifier;
-	struct mutex lock;
-	struct pm_qos_request int_req;
-	struct clk *int_clk;
-};
-
-struct int_bus_opp_table {
-	unsigned int idx;
-	unsigned long clk;
-	unsigned long volt;
-};
-
-static struct int_bus_opp_table exynos5_int_opp_table[] = {
-	{LV_0, 266000, 1025000},
-	{LV_1, 200000, 1025000},
-	{LV_2, 160000, 1025000},
-	{LV_3, 133000, 1025000},
-	{LV_4, 100000, 1025000},
-	{0, 0, 0},
-};
-
-static int exynos5_int_setvolt(struct busfreq_data_int *data,
-				unsigned long volt)
-{
-	return regulator_set_voltage(data->vdd_int, volt, MAX_SAFEVOLT);
-}
-
-static int exynos5_busfreq_int_target(struct device *dev, unsigned long *_freq,
-			      u32 flags)
-{
-	int err = 0;
-	struct platform_device *pdev = container_of(dev, struct platform_device,
-						    dev);
-	struct busfreq_data_int *data = platform_get_drvdata(pdev);
-	struct dev_pm_opp *opp;
-	unsigned long old_freq, freq;
-	unsigned long volt;
-
-	rcu_read_lock();
-	opp = devfreq_recommended_opp(dev, _freq, flags);
-	if (IS_ERR(opp)) {
-		rcu_read_unlock();
-		dev_err(dev, "%s: Invalid OPP.\n", __func__);
-		return PTR_ERR(opp);
-	}
-
-	freq = dev_pm_opp_get_freq(opp);
-	volt = dev_pm_opp_get_voltage(opp);
-	rcu_read_unlock();
-
-	old_freq = data->curr_freq;
-
-	if (old_freq == freq)
-		return 0;
-
-	dev_dbg(dev, "targeting %lukHz %luuV\n", freq, volt);
-
-	mutex_lock(&data->lock);
-
-	if (data->disabled)
-		goto out;
-
-	if (freq > exynos5_int_opp_table[0].clk)
-		pm_qos_update_request(&data->int_req, freq * 16 / 1000);
-	else
-		pm_qos_update_request(&data->int_req, -1);
-
-	if (old_freq < freq)
-		err = exynos5_int_setvolt(data, volt);
-	if (err)
-		goto out;
-
-	err = clk_set_rate(data->int_clk, freq * 1000);
-
-	if (err)
-		goto out;
-
-	if (old_freq > freq)
-		err = exynos5_int_setvolt(data, volt);
-	if (err)
-		goto out;
-
-	data->curr_freq = freq;
-out:
-	mutex_unlock(&data->lock);
-	return err;
-}
-
-static int exynos5_int_get_dev_status(struct device *dev,
-				      struct devfreq_dev_status *stat)
-{
-	struct platform_device *pdev = container_of(dev, struct platform_device,
-						    dev);
-	struct busfreq_data_int *data = platform_get_drvdata(pdev);
-	struct busfreq_ppmu_data *ppmu_data = &data->ppmu_data;
-	int busier_dmc;
-
-	exynos_read_ppmu(ppmu_data);
-	busier_dmc = exynos_get_busier_ppmu(ppmu_data);
-
-	stat->current_frequency = data->curr_freq;
-
-	/* Number of cycles spent on memory access */
-	stat->busy_time = ppmu_data->ppmu[busier_dmc].count[PPMU_PMNCNT3];
-	stat->busy_time *= 100 / INT_BUS_SATURATION_RATIO;
-	stat->total_time = ppmu_data->ppmu[busier_dmc].ccnt;
-
-	return 0;
-}
-
-static struct devfreq_dev_profile exynos5_devfreq_int_profile = {
-	.initial_freq		= 160000,
-	.polling_ms		= 100,
-	.target			= exynos5_busfreq_int_target,
-	.get_dev_status		= exynos5_int_get_dev_status,
-};
-
-static int exynos5250_init_int_tables(struct busfreq_data_int *data)
-{
-	int i, err = 0;
-
-	for (i = LV_0; i < _LV_END; i++) {
-		err = dev_pm_opp_add(data->dev, exynos5_int_opp_table[i].clk,
-				exynos5_int_opp_table[i].volt);
-		if (err) {
-			dev_err(data->dev, "Cannot add opp entries.\n");
-			return err;
-		}
-	}
-
-	return 0;
-}
-
-static int exynos5_busfreq_int_pm_notifier_event(struct notifier_block *this,
-		unsigned long event, void *ptr)
-{
-	struct busfreq_data_int *data = container_of(this,
-					struct busfreq_data_int, pm_notifier);
-	struct dev_pm_opp *opp;
-	unsigned long maxfreq = ULONG_MAX;
-	unsigned long freq;
-	unsigned long volt;
-	int err = 0;
-
-	switch (event) {
-	case PM_SUSPEND_PREPARE:
-		/* Set Fastest and Deactivate DVFS */
-		mutex_lock(&data->lock);
-
-		data->disabled = true;
-
-		rcu_read_lock();
-		opp = dev_pm_opp_find_freq_floor(data->dev, &maxfreq);
-		if (IS_ERR(opp)) {
-			rcu_read_unlock();
-			err = PTR_ERR(opp);
-			goto unlock;
-		}
-		freq = dev_pm_opp_get_freq(opp);
-		volt = dev_pm_opp_get_voltage(opp);
-		rcu_read_unlock();
-
-		err = exynos5_int_setvolt(data, volt);
-		if (err)
-			goto unlock;
-
-		err = clk_set_rate(data->int_clk, freq * 1000);
-
-		if (err)
-			goto unlock;
-
-		data->curr_freq = freq;
-unlock:
-		mutex_unlock(&data->lock);
-		if (err)
-			return NOTIFY_BAD;
-		return NOTIFY_OK;
-	case PM_POST_RESTORE:
-	case PM_POST_SUSPEND:
-		/* Reactivate */
-		mutex_lock(&data->lock);
-		data->disabled = false;
-		mutex_unlock(&data->lock);
-		return NOTIFY_OK;
-	}
-
-	return NOTIFY_DONE;
-}
-
-static int exynos5_busfreq_int_probe(struct platform_device *pdev)
-{
-	struct busfreq_data_int *data;
-	struct busfreq_ppmu_data *ppmu_data;
-	struct dev_pm_opp *opp;
-	struct device *dev = &pdev->dev;
-	struct device_node *np;
-	unsigned long initial_freq;
-	unsigned long initial_volt;
-	int err = 0;
-	int i;
-
-	data = devm_kzalloc(&pdev->dev, sizeof(struct busfreq_data_int),
-				GFP_KERNEL);
-	if (data == NULL) {
-		dev_err(dev, "Cannot allocate memory.\n");
-		return -ENOMEM;
-	}
-
-	ppmu_data = &data->ppmu_data;
-	ppmu_data->ppmu_end = PPMU_END;
-	ppmu_data->ppmu = devm_kzalloc(dev,
-				       sizeof(struct exynos_ppmu) * PPMU_END,
-				       GFP_KERNEL);
-	if (!ppmu_data->ppmu) {
-		dev_err(dev, "Failed to allocate memory for exynos_ppmu\n");
-		return -ENOMEM;
-	}
-
-	np = of_find_compatible_node(NULL, NULL, "samsung,exynos5250-ppmu");
-	if (np == NULL) {
-		pr_err("Unable to find PPMU node\n");
-		return -ENOENT;
-	}
-
-	for (i = 0; i < ppmu_data->ppmu_end; i++) {
-		/* map PPMU memory region */
-		ppmu_data->ppmu[i].hw_base = of_iomap(np, i);
-		if (ppmu_data->ppmu[i].hw_base == NULL) {
-			dev_err(&pdev->dev, "failed to map memory region\n");
-			return -ENOMEM;
-		}
-	}
-	data->pm_notifier.notifier_call = exynos5_busfreq_int_pm_notifier_event;
-	data->dev = dev;
-	mutex_init(&data->lock);
-
-	err = exynos5250_init_int_tables(data);
-	if (err)
-		return err;
-
-	data->vdd_int = devm_regulator_get(dev, "vdd_int");
-	if (IS_ERR(data->vdd_int)) {
-		dev_err(dev, "Cannot get the regulator \"vdd_int\"\n");
-		return PTR_ERR(data->vdd_int);
-	}
-
-	data->int_clk = devm_clk_get(dev, "int_clk");
-	if (IS_ERR(data->int_clk)) {
-		dev_err(dev, "Cannot get clock \"int_clk\"\n");
-		return PTR_ERR(data->int_clk);
-	}
-
-	rcu_read_lock();
-	opp = dev_pm_opp_find_freq_floor(dev,
-			&exynos5_devfreq_int_profile.initial_freq);
-	if (IS_ERR(opp)) {
-		rcu_read_unlock();
-		dev_err(dev, "Invalid initial frequency %lu kHz.\n",
-		       exynos5_devfreq_int_profile.initial_freq);
-		return PTR_ERR(opp);
-	}
-	initial_freq = dev_pm_opp_get_freq(opp);
-	initial_volt = dev_pm_opp_get_voltage(opp);
-	rcu_read_unlock();
-	data->curr_freq = initial_freq;
-
-	err = clk_set_rate(data->int_clk, initial_freq * 1000);
-	if (err) {
-		dev_err(dev, "Failed to set initial frequency\n");
-		return err;
-	}
-
-	err = exynos5_int_setvolt(data, initial_volt);
-	if (err)
-		return err;
-
-	platform_set_drvdata(pdev, data);
-
-	busfreq_mon_reset(ppmu_data);
-
-	data->devfreq = devm_devfreq_add_device(dev, &exynos5_devfreq_int_profile,
-					   "simple_ondemand", NULL);
-	if (IS_ERR(data->devfreq))
-		return PTR_ERR(data->devfreq);
-
-	err = devm_devfreq_register_opp_notifier(dev, data->devfreq);
-	if (err < 0) {
-		dev_err(dev, "Failed to register opp notifier\n");
-		return err;
-	}
-
-	err = register_pm_notifier(&data->pm_notifier);
-	if (err) {
-		dev_err(dev, "Failed to setup pm notifier\n");
-		return err;
-	}
-
-	/* TODO: Add a new QOS class for int/mif bus */
-	pm_qos_add_request(&data->int_req, PM_QOS_NETWORK_THROUGHPUT, -1);
-
-	return 0;
-}
-
-static int exynos5_busfreq_int_remove(struct platform_device *pdev)
-{
-	struct busfreq_data_int *data = platform_get_drvdata(pdev);
-
-	pm_qos_remove_request(&data->int_req);
-	unregister_pm_notifier(&data->pm_notifier);
-
-	return 0;
-}
-
-#ifdef CONFIG_PM_SLEEP
-static int exynos5_busfreq_int_resume(struct device *dev)
-{
-	struct platform_device *pdev = container_of(dev, struct platform_device,
-						    dev);
-	struct busfreq_data_int *data = platform_get_drvdata(pdev);
-	struct busfreq_ppmu_data *ppmu_data = &data->ppmu_data;
-
-	busfreq_mon_reset(ppmu_data);
-	return 0;
-}
-static const struct dev_pm_ops exynos5_busfreq_int_pm = {
-	.resume	= exynos5_busfreq_int_resume,
-};
-#endif
-static SIMPLE_DEV_PM_OPS(exynos5_busfreq_int_pm_ops, NULL,
-			 exynos5_busfreq_int_resume);
-
-/* platform device pointer for exynos5 devfreq device. */
-static struct platform_device *exynos5_devfreq_pdev;
-
-static struct platform_driver exynos5_busfreq_int_driver = {
-	.probe		= exynos5_busfreq_int_probe,
-	.remove		= exynos5_busfreq_int_remove,
-	.driver		= {
-		.name		= "exynos5-bus-int",
-		.pm		= &exynos5_busfreq_int_pm_ops,
-	},
-};
-
-static int __init exynos5_busfreq_int_init(void)
-{
-	int ret;
-
-	ret = platform_driver_register(&exynos5_busfreq_int_driver);
-	if (ret < 0)
-		goto out;
-
-	exynos5_devfreq_pdev =
-		platform_device_register_simple("exynos5-bus-int", -1, NULL, 0);
-	if (IS_ERR(exynos5_devfreq_pdev)) {
-		ret = PTR_ERR(exynos5_devfreq_pdev);
-		goto out1;
-	}
-
-	return 0;
-out1:
-	platform_driver_unregister(&exynos5_busfreq_int_driver);
-out:
-	return ret;
-}
-late_initcall(exynos5_busfreq_int_init);
-
-static void __exit exynos5_busfreq_int_exit(void)
-{
-	platform_device_unregister(exynos5_devfreq_pdev);
-	platform_driver_unregister(&exynos5_busfreq_int_driver);
-}
-module_exit(exynos5_busfreq_int_exit);
-
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("EXYNOS5 busfreq driver with devfreq framework");

drivers/devfreq/exynos/exynos_ppmu.c

-/*
- * Copyright (c) 2012 Samsung Electronics Co., Ltd.
- *		http://www.samsung.com/
- *
- * EXYNOS - PPMU support
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-
-#include <linux/kernel.h>
-#include <linux/types.h>
-#include <linux/io.h>
-
-#include "exynos_ppmu.h"
-
-void exynos_ppmu_reset(void __iomem *ppmu_base)
-{
-	__raw_writel(PPMU_CYCLE_RESET | PPMU_COUNTER_RESET, ppmu_base);
-	__raw_writel(PPMU_ENABLE_CYCLE  |
-		     PPMU_ENABLE_COUNT0 |
-		     PPMU_ENABLE_COUNT1 |
-		     PPMU_ENABLE_COUNT2 |
-		     PPMU_ENABLE_COUNT3,
-		     ppmu_base + PPMU_CNTENS);
-}
-
-void exynos_ppmu_setevent(void __iomem *ppmu_base, unsigned int ch,
-			unsigned int evt)
-{
-	__raw_writel(evt, ppmu_base + PPMU_BEVTSEL(ch));
-}
-
-void exynos_ppmu_start(void __iomem *ppmu_base)
-{
-	__raw_writel(PPMU_ENABLE, ppmu_base);
-}
-
-void exynos_ppmu_stop(void __iomem *ppmu_base)
-{
-	__raw_writel(PPMU_DISABLE, ppmu_base);
-}
-
-unsigned int exynos_ppmu_read(void __iomem *ppmu_base, unsigned int ch)
-{
-	unsigned int total;
-
-	if (ch == PPMU_PMNCNT3)
-		total = ((__raw_readl(ppmu_base + PMCNT_OFFSET(ch)) << 8) |
-			  __raw_readl(ppmu_base + PMCNT_OFFSET(ch + 1)));
-	else
-		total = __raw_readl(ppmu_base + PMCNT_OFFSET(ch));
-
-	return total;
-}
-
-void busfreq_mon_reset(struct busfreq_ppmu_data *ppmu_data)
-{
-	unsigned int i;
-
-	for (i = 0; i < ppmu_data->ppmu_end; i++) {
-		void __iomem *ppmu_base = ppmu_data->ppmu[i].hw_base;
-
-		/* Reset the performance and cycle counters */
-		exynos_ppmu_reset(ppmu_base);
-
-		/* Setup count registers to monitor read/write transactions */
-		ppmu_data->ppmu[i].event[PPMU_PMNCNT3] = RDWR_DATA_COUNT;
-		exynos_ppmu_setevent(ppmu_base, PPMU_PMNCNT3,
-					ppmu_data->ppmu[i].event[PPMU_PMNCNT3]);
-
-		exynos_ppmu_start(ppmu_base);
-	}
-}
-EXPORT_SYMBOL(busfreq_mon_reset);
-
-void exynos_read_ppmu(struct busfreq_ppmu_data *ppmu_data)
-{
-	int i, j;
-
-	for (i = 0; i < ppmu_data->ppmu_end; i++) {
-		void __iomem *ppmu_base = ppmu_data->ppmu[i].hw_base;
-
-		exynos_ppmu_stop(ppmu_base);
-
-		/* Update local data from PPMU */
-		ppmu_data->ppmu[i].ccnt = __raw_readl(ppmu_base + PPMU_CCNT);
-
-		for (j = PPMU_PMNCNT0; j < PPMU_PMNCNT_MAX; j++) {
-			if (ppmu_data->ppmu[i].event[j] == 0)
-				ppmu_data->ppmu[i].count[j] = 0;
-			else
-				ppmu_data->ppmu[i].count[j] =
-					exynos_ppmu_read(ppmu_base, j);
-		}
-	}
-
-	busfreq_mon_reset(ppmu_data);
-}
-EXPORT_SYMBOL(exynos_read_ppmu);
-
-int exynos_get_busier_ppmu(struct busfreq_ppmu_data *ppmu_data)
-{
-	unsigned int count = 0;
-	int i, j, busy = 0;
-
-	for (i = 0; i < ppmu_data->ppmu_end; i++) {
-		for (j = PPMU_PMNCNT0; j < PPMU_PMNCNT_MAX; j++) {
-			if (ppmu_data->ppmu[i].count[j] > count) {
-				count = ppmu_data->ppmu[i].count[j];
-				busy = i;
-			}
-		}
-	}
-
-	return busy;
-}
-EXPORT_SYMBOL(exynos_get_busier_ppmu);

drivers/devfreq/exynos/exynos_ppmu.h

-/*
- * Copyright (c) 2012 Samsung Electronics Co., Ltd.
- *		http://www.samsung.com/
- *
- * EXYNOS PPMU header
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
-*/
-
-#ifndef __DEVFREQ_EXYNOS_PPMU_H
-#define __DEVFREQ_EXYNOS_PPMU_H __FILE__
-
-#include <linux/ktime.h>
-
-/* For PPMU Control */
-#define PPMU_ENABLE             BIT(0)
-#define PPMU_DISABLE            0x0
-#define PPMU_CYCLE_RESET        BIT(1)
-#define PPMU_COUNTER_RESET      BIT(2)
-
-#define PPMU_ENABLE_COUNT0      BIT(0)
-#define PPMU_ENABLE_COUNT1      BIT(1)
-#define PPMU_ENABLE_COUNT2      BIT(2)
-#define PPMU_ENABLE_COUNT3      BIT(3)
-#define PPMU_ENABLE_CYCLE       BIT(31)
-
-#define PPMU_CNTENS		0x10
-#define PPMU_FLAG		0x50
-#define PPMU_CCNT_OVERFLOW	BIT(31)
-#define PPMU_CCNT		0x100
-
-#define PPMU_PMCNT0		0x110
-#define PPMU_PMCNT_OFFSET	0x10
-#define PMCNT_OFFSET(x)		(PPMU_PMCNT0 + (PPMU_PMCNT_OFFSET * x))
-
-#define PPMU_BEVT0SEL		0x1000
-#define PPMU_BEVTSEL_OFFSET	0x100
-#define PPMU_BEVTSEL(x)		(PPMU_BEVT0SEL + (ch * PPMU_BEVTSEL_OFFSET))
-
-/* For Event Selection */
-#define RD_DATA_COUNT		0x5
-#define WR_DATA_COUNT		0x6
-#define RDWR_DATA_COUNT		0x7
-
-enum ppmu_counter {
-	PPMU_PMNCNT0,
-	PPMU_PMCCNT1,
-	PPMU_PMNCNT2,
-	PPMU_PMNCNT3,
-	PPMU_PMNCNT_MAX,
-};
-
-struct bus_opp_table {
-	unsigned int idx;
-	unsigned long clk;
-	unsigned long volt;
-};
-
-struct exynos_ppmu {
-	void __iomem *hw_base;
-	unsigned int ccnt;
-	unsigned int event[PPMU_PMNCNT_MAX];
-	unsigned int count[PPMU_PMNCNT_MAX];
-	unsigned long long ns;
-	ktime_t reset_time;
-	bool ccnt_overflow;
-	bool count_overflow[PPMU_PMNCNT_MAX];
-};
-
-struct busfreq_ppmu_data {
-	struct exynos_ppmu *ppmu;
-	int ppmu_end;
-};
-
-void exynos_ppmu_reset(void __iomem *ppmu_base);
-void exynos_ppmu_setevent(void __iomem *ppmu_base, unsigned int ch,
-			unsigned int evt);
-void exynos_ppmu_start(void __iomem *ppmu_base);
-void exynos_ppmu_stop(void __iomem *ppmu_base);
-unsigned int exynos_ppmu_read(void __iomem *ppmu_base, unsigned int ch);
-void busfreq_mon_reset(struct busfreq_ppmu_data *ppmu_data);
-void exynos_read_ppmu(struct busfreq_ppmu_data *ppmu_data);
-int exynos_get_busier_ppmu(struct busfreq_ppmu_data *ppmu_data);
-#endif /* __DEVFREQ_EXYNOS_PPMU_H */

drivers/devfreq/governor_passive.c

+/*
+ * linux/drivers/devfreq/governor_passive.c
+ *
+ * Copyright (C) 2016 Samsung Electronics
+ * Author: Chanwoo Choi <cw00.choi@samsung.com>
+ * Author: MyungJoo Ham <myungjoo.ham@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/devfreq.h>
+#include "governor.h"
+
+static int devfreq_passive_get_target_freq(struct devfreq *devfreq,
+					unsigned long *freq)
+{
+	struct devfreq_passive_data *p_data
+			= (struct devfreq_passive_data *)devfreq->data;
+	struct devfreq *parent_devfreq = (struct devfreq *)p_data->parent;
+	unsigned long child_freq = ULONG_MAX;
+	struct dev_pm_opp *opp;
+	int i, count, ret = 0;
+
+	/*
+	 * If the devfreq device with passive governor has the specific method
+	 * to determine the next frequency, should use the get_target_freq()
+	 * of struct devfreq_passive_data.
+	 */
+	if (p_data->get_target_freq) {
+		ret = p_data->get_target_freq(devfreq, freq);
+		goto out;
+	}
+
+	/*
+	 * If the parent and passive devfreq device uses the OPP table,
+	 * get the next frequency by using the OPP table.
+	 */
+
+	/*
+	 * - parent devfreq device uses the governors except for passive.
+	 * - passive devfreq device uses the passive governor.
+	 *
+	 * Each devfreq has the OPP table. After deciding the new frequency
+	 * from the governor of parent devfreq device, the passive governor
+	 * need to get the index of new frequency on OPP table of parent
+	 * device. And then the index is used for getting the suitable
+	 * new frequency for passive devfreq device.
+	 */
+	if (!devfreq->profile || !devfreq->profile->freq_table
+		|| devfreq->profile->max_state <= 0)
+		return -EINVAL;
+
+	/*
+	 * The passive governor have to get the correct frequency from OPP
+	 * list of parent device. Because in this case, *freq is temporary
+	 * value which is decided by ondemand governor.
+	 */
+	rcu_read_lock();
+	opp = devfreq_recommended_opp(parent_devfreq->dev.parent, freq, 0);
+	rcu_read_unlock();
+	if (IS_ERR(opp)) {
+		ret = PTR_ERR(opp);
+		goto out;
+	}
+
+	/*
+	 * Get the OPP table's index of decided freqeuncy by governor
+	 * of parent device.
+	 */
+	for (i = 0; i < parent_devfreq->profile->max_state; i++)
+		if (parent_devfreq->profile->freq_table[i] == *freq)
+			break;
+
+	if (i == parent_devfreq->profile->max_state) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* Get the suitable frequency by using index of parent device. */
+	if (i < devfreq->profile->max_state) {
+		child_freq = devfreq->profile->freq_table[i];
+	} else {
+		count = devfreq->profile->max_state;
+		child_freq = devfreq->profile->freq_table[count - 1];
+	}
+
+	/* Return the suitable frequency for passive device. */
+	*freq = child_freq;
+
+out:
+	return ret;
+}
+
+static int update_devfreq_passive(struct devfreq *devfreq, unsigned long freq)
+{
+	int ret;
+
+	if (!devfreq->governor)
+		return -EINVAL;
+
+	mutex_lock_nested(&devfreq->lock, SINGLE_DEPTH_NESTING);
+
+	ret = devfreq->governor->get_target_freq(devfreq, &freq);
+	if (ret < 0)
+		goto out;
+
+	ret = devfreq->profile->target(devfreq->dev.parent, &freq, 0);
+	if (ret < 0)
+		goto out;
+
+	devfreq->previous_freq = freq;
+
+out:
+	mutex_unlock(&devfreq->lock);
+
+	return 0;
+}
+
+static int devfreq_passive_notifier_call(struct notifier_block *nb,
+				unsigned long event, void *ptr)
+{
+	struct devfreq_passive_data *data
+			= container_of(nb, struct devfreq_passive_data, nb);
+	struct devfreq *devfreq = (struct devfreq *)data->this;
+	struct devfreq *parent = (struct devfreq *)data->parent;
+	struct devfreq_freqs *freqs = (struct devfreq_freqs *)ptr;
+	unsigned long freq = freqs->new;
+
+	switch (event) {
+	case DEVFREQ_PRECHANGE:
+		if (parent->previous_freq > freq)
+			update_devfreq_passive(devfreq, freq);
+		break;
+	case DEVFREQ_POSTCHANGE:
+		if (parent->previous_freq < freq)
+			update_devfreq_passive(devfreq, freq);
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+static int devfreq_passive_event_handler(struct devfreq *devfreq,
+				unsigned int event, void *data)
+{
+	struct device *dev = devfreq->dev.parent;
+	struct devfreq_passive_data *p_data
+			= (struct devfreq_passive_data *)devfreq->data;
+	struct devfreq *parent = (struct devfreq *)p_data->parent;
+	struct notifier_block *nb = &p_data->nb;
+	int ret = 0;
+
+	if (!parent)
+		return -EPROBE_DEFER;
+
+	switch (event) {
+	case DEVFREQ_GOV_START:
+		if (!p_data->this)
+			p_data->this = devfreq;
+
+		nb->notifier_call = devfreq_passive_notifier_call;
+		ret = devm_devfreq_register_notifier(dev, parent, nb,
+					DEVFREQ_TRANSITION_NOTIFIER);
+		break;
+	case DEVFREQ_GOV_STOP:
+		devm_devfreq_unregister_notifier(dev, parent, nb,
+					DEVFREQ_TRANSITION_NOTIFIER);
+		break;
+	default:
+		break;
+	}
+
+	return ret;
+}
+
+static struct devfreq_governor devfreq_passive = {
+	.name = "passive",
+	.get_target_freq = devfreq_passive_get_target_freq,
+	.event_handler = devfreq_passive_event_handler,
+};
+
+static int __init devfreq_passive_init(void)
+{
+	return devfreq_add_governor(&devfreq_passive);
+}
+subsys_initcall(devfreq_passive_init);
+
+static void __exit devfreq_passive_exit(void)
+{
+	int ret;
+
+	ret = devfreq_remove_governor(&devfreq_passive);
+	if (ret)
+		pr_err("%s: failed remove governor %d\n", __func__, ret);
+}
+module_exit(devfreq_passive_exit);
+
+MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
+MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
+MODULE_DESCRIPTION("DEVFREQ Passive governor");
+MODULE_LICENSE("GPL v2");

include/linux/devfreq.h

@@ -19,6 +19,13 @@
 
 #define DEVFREQ_NAME_LEN 16
 
+/* DEVFREQ notifier interface */
+#define DEVFREQ_TRANSITION_NOTIFIER	(0)
+
+/* Transition notifiers of DEVFREQ_TRANSITION_NOTIFIER */
+#define	DEVFREQ_PRECHANGE		(0)
+#define DEVFREQ_POSTCHANGE		(1)
+
 struct devfreq;
 
 /**
@@ -143,6 +150,7 @@ struct devfreq_governor {
  * @trans_table:	Statistics of devfreq transitions
  * @time_in_state:	Statistics of devfreq states
  * @last_stat_updated:	The last time stat updated
+ * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier
  *
  * This structure stores the devfreq information for a give device.
  *
@@ -177,6 +185,13 @@ struct devfreq {
 	unsigned int *trans_table;
 	unsigned long *time_in_state;
 	unsigned long last_stat_updated;
+
+	struct srcu_notifier_head transition_notifier_list;
+};
+
+struct devfreq_freqs {
+	unsigned long old;
+	unsigned long new;
 };
 
 #if defined(CONFIG_PM_DEVFREQ)
@@ -207,6 +222,22 @@ extern int devm_devfreq_register_opp_notifier(struct device *dev,
 					      struct devfreq *devfreq);
 extern void devm_devfreq_unregister_opp_notifier(struct device *dev,
 						struct devfreq *devfreq);
+extern int devfreq_register_notifier(struct devfreq *devfreq,
+					struct notifier_block *nb,
+					unsigned int list);
+extern int devfreq_unregister_notifier(struct devfreq *devfreq,
+					struct notifier_block *nb,
+					unsigned int list);
+extern int devm_devfreq_register_notifier(struct device *dev,
+				struct devfreq *devfreq,
+				struct notifier_block *nb,
+				unsigned int list);
+extern void devm_devfreq_unregister_notifier(struct device *dev,
+				struct devfreq *devfreq,
+				struct notifier_block *nb,
+				unsigned int list);
+extern struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
+						int index);
 
 /**
  * devfreq_update_stats() - update the last_status pointer in struct devfreq
@@ -241,6 +272,39 @@ struct devfreq_simple_ondemand_data {
 };
 #endif
 
+#if IS_ENABLED(CONFIG_DEVFREQ_GOV_PASSIVE)
+/**
+ * struct devfreq_passive_data - void *data fed to struct devfreq
+ *	and devfreq_add_device
+ * @parent:	the devfreq instance of parent device.
+ * @get_target_freq:	Optional callback, Returns desired operating frequency
+ *			for the device using passive governor. That is called
+ *			when passive governor should decide the next frequency
+ *			by using the new frequency of parent devfreq device
+ *			using governors except for passive governor.
+ *			If the devfreq device has the specific method to decide
+ *			the next frequency, should use this callback.
+ * @this:	the devfreq instance of own device.
+ * @nb:		the notifier block for DEVFREQ_TRANSITION_NOTIFIER list
+ *
+ * The devfreq_passive_data have to set the devfreq instance of parent
+ * device with governors except for the passive governor. But, don't need to
+ * initialize the 'this' and 'nb' field because the devfreq core will handle
+ * them.
+ */
+struct devfreq_passive_data {
+	/* Should set the devfreq instance of parent device */
+	struct devfreq *parent;
+
+	/* Optional callback to decide the next frequency of passvice device */
+	int (*get_target_freq)(struct devfreq *this, unsigned long *freq);
+
+	/* For passive governor's internal use. Don't need to set them */
+	struct devfreq *this;
+	struct notifier_block nb;
+};
+#endif
+
 #else /* !CONFIG_PM_DEVFREQ */
 static inline struct devfreq *devfreq_add_device(struct device *dev,
 					  struct devfreq_dev_profile *profile,
@@ -307,6 +371,41 @@ static inline void devm_devfreq_unregister_opp_notifier(struct device *dev,
 {
 }
 
+static inline int devfreq_register_notifier(struct devfreq *devfreq,
+					struct notifier_block *nb,
+					unsigned int list)
+{
+	return 0;
+}
+
+static inline int devfreq_unregister_notifier(struct devfreq *devfreq,
+					struct notifier_block *nb,
+					unsigned int list)
+{
+	return 0;
+}
+
+static inline int devm_devfreq_register_notifier(struct device *dev,
+				struct devfreq *devfreq,
+				struct notifier_block *nb,
+				unsigned int list)
+{
+	return 0;
+}
+
+static inline void devm_devfreq_unregister_notifier(struct device *dev,
+				struct devfreq *devfreq,
+				struct notifier_block *nb,
+				unsigned int list)
+{
+}
+
+static inline struct devfreq *devfreq_get_devfreq_by_phandle(struct device *dev,
+							int index)
+{
+	return ERR_PTR(-ENODEV);
+}
+
 static inline int devfreq_update_stats(struct devfreq *df)
 {
 	return -EINVAL;