CLK: Add binding document for Pistachio clock controllers

Add a device-tree binding document describing the four clock
controllers present on the IMG Pistachio SoC.
Signed-off-by: NDamien Horsley <Damien.Horsley@imgtec.com>
Signed-off-by: NAndrew Bresticker <abrestic@chromium.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: devicetree@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Ezequiel Garcia <ezequiel.garcia@imgtec.com>
Cc: James Hartley <james.hartley@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Damien Horsley <Damien.Horsley@imgtec.com>
Acked-by: NStephen Boyd <sboyd@codeaurora.org>
Patchwork: https://patchwork.linux-mips.org/patch/9319/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Documentation/devicetree/bindings/clock/pistachio-clock.txt

+Imagination Technologies Pistachio SoC clock controllers
+========================================================
+
+Pistachio has four clock controllers (core clock, peripheral clock, peripheral
+general control, and top general control) which are instantiated individually
+from the device-tree.
+
+External clocks:
+----------------
+
+There are three external inputs to the clock controllers which should be
+defined with the following clock-output-names:
+- "xtal": External 52Mhz oscillator (required)
+- "audio_clk_in": Alternate audio reference clock (optional)
+- "enet_clk_in": Alternate ethernet PHY clock (optional)
+
+Core clock controller:
+----------------------
+
+The core clock controller generates clocks for the CPU, RPU (WiFi + BT
+co-processor), audio, and several peripherals.
+
+Required properties:
+- compatible: Must be "img,pistachio-clk".
+- reg: Must contain the base address and length of the core clock controller.
+- #clock-cells: Must be 1.  The single cell is the clock identifier.
+  See dt-bindings/clock/pistachio-clk.h for the list of valid identifiers.
+- clocks: Must contain an entry for each clock in clock-names.
+- clock-names: Must include "xtal" (see "External clocks") and
+  "audio_clk_in_gate", "enet_clk_in_gate" which are generated by the
+  top-level general control.
+
+Example:
+	clk_core: clock-controller@18144000 {
+		compatible = "img,pistachio-clk";
+		reg = <0x18144000 0x800>;
+		clocks = <&xtal>, <&cr_top EXT_CLK_AUDIO_IN>,
+			 <&cr_top EXT_CLK_ENET_IN>;
+		clock-names = "xtal", "audio_clk_in_gate", "enet_clk_in_gate";
+
+		#clock-cells = <1>;
+	};
+
+Peripheral clock controller:
+----------------------------
+
+The peripheral clock controller generates clocks for the DDR, ROM, and other
+peripherals.  The peripheral system clock ("periph_sys") generated by the core
+clock controller is the input clock to the peripheral clock controller.
+
+Required properties:
+- compatible: Must be "img,pistachio-periph-clk".
+- reg: Must contain the base address and length of the peripheral clock
+  controller.
+- #clock-cells: Must be 1.  The single cell is the clock identifier.
+  See dt-bindings/clock/pistachio-clk.h for the list of valid identifiers.
+- clocks: Must contain an entry for each clock in clock-names.
+- clock-names: Must include "periph_sys", the peripheral system clock generated
+  by the core clock controller.
+
+Example:
+	clk_periph: clock-controller@18144800 {
+		compatible = "img,pistachio-clk-periph";
+		reg = <0x18144800 0x800>;
+		clocks = <&clk_core CLK_PERIPH_SYS>;
+		clock-names = "periph_sys";
+
+		#clock-cells = <1>;
+	};
+
+Peripheral general control:
+---------------------------
+
+The peripheral general control block generates system interface clocks and
+resets for various peripherals.  It also contains miscellaneous peripheral
+control registers.  The system clock ("sys") generated by the peripheral clock
+controller is the input clock to the system clock controller.
+
+Required properties:
+- compatible: Must include "img,pistachio-periph-cr" and "syscon".
+- reg: Must contain the base address and length of the peripheral general
+  control registers.
+- #clock-cells: Must be 1.  The single cell is the clock identifier.
+  See dt-bindings/clock/pistachio-clk.h for the list of valid identifiers.
+- clocks: Must contain an entry for each clock in clock-names.
+- clock-names: Must include "sys", the system clock generated by the peripheral
+  clock controller.
+
+Example:
+	cr_periph: syscon@18144800 {
+		compatible = "img,pistachio-cr-periph", "syscon";
+		reg = <0x18148000 0x1000>;
+		clocks = <&clock_periph PERIPH_CLK_PERIPH_SYS>;
+		clock-names = "sys";
+
+		#clock-cells = <1>;
+	};
+
+Top-level general control:
+--------------------------
+
+The top-level general control block contains miscellaneous control registers and
+gates for the external clocks "audio_clk_in" and "enet_clk_in".
+
+Required properties:
+- compatible: Must include "img,pistachio-cr-top" and "syscon".
+- reg: Must contain the base address and length of the top-level
+  control registers.
+- clocks: Must contain an entry for each clock in clock-names.
+- clock-names: Two optional clocks, "audio_clk_in" and "enet_clk_in" (see
+  "External clocks").
+- #clock-cells: Must be 1.  The single cell is the clock identifier.
+  See dt-bindings/clock/pistachio-clk.h for the list of valid identifiers.
+
+Example:
+	cr_top: syscon@18144800 {
+		compatible = "img,pistachio-cr-top", "syscon";
+		reg = <0x18149000 0x200>;
+		clocks = <&audio_refclk>, <&ext_enet_in>;
+		clock-names = "audio_clk_in", "enet_clk_in";
+
+		#clock-cells = <1>;
+	};

include/dt-bindings/clock/pistachio-clk.h

+/*
+ * Copyright (C) 2014 Google, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ */
+
+#ifndef _DT_BINDINGS_CLOCK_PISTACHIO_H
+#define _DT_BINDINGS_CLOCK_PISTACHIO_H
+
+/* PLLs */
+#define CLK_MIPS_PLL			0
+#define CLK_AUDIO_PLL			1
+#define CLK_RPU_V_PLL			2
+#define CLK_RPU_L_PLL			3
+#define CLK_SYS_PLL			4
+#define CLK_WIFI_PLL			5
+#define CLK_BT_PLL			6
+
+/* Fixed-factor clocks */
+#define CLK_WIFI_DIV4			16
+#define CLK_WIFI_DIV8			17
+
+/* Gate clocks */
+#define CLK_MIPS			32
+#define CLK_AUDIO_IN			33
+#define CLK_AUDIO			34
+#define CLK_I2S				35
+#define CLK_SPDIF			36
+#define CLK_AUDIO_DAC			37
+#define CLK_RPU_V			38
+#define CLK_RPU_L			39
+#define CLK_RPU_SLEEP			40
+#define CLK_WIFI_PLL_GATE		41
+#define CLK_RPU_CORE			42
+#define CLK_WIFI_ADC			43
+#define CLK_WIFI_DAC			44
+#define CLK_USB_PHY			45
+#define CLK_ENET_IN			46
+#define CLK_ENET			47
+#define CLK_UART0			48
+#define CLK_UART1			49
+#define CLK_PERIPH_SYS			50
+#define CLK_SPI0			51
+#define CLK_SPI1			52
+#define CLK_EVENT_TIMER			53
+#define CLK_AUX_ADC_INTERNAL		54
+#define CLK_AUX_ADC			55
+#define CLK_SD_HOST			56
+#define CLK_BT				57
+#define CLK_BT_DIV4			58
+#define CLK_BT_DIV8			59
+#define CLK_BT_1MHZ			60
+
+/* Divider clocks */
+#define CLK_MIPS_INTERNAL_DIV		64
+#define CLK_MIPS_DIV			65
+#define CLK_AUDIO_DIV			66
+#define CLK_I2S_DIV			67
+#define CLK_SPDIF_DIV			68
+#define CLK_AUDIO_DAC_DIV		69
+#define CLK_RPU_V_DIV			70
+#define CLK_RPU_L_DIV			71
+#define CLK_RPU_SLEEP_DIV		72
+#define CLK_RPU_CORE_DIV		73
+#define CLK_USB_PHY_DIV			74
+#define CLK_ENET_DIV			75
+#define CLK_UART0_INTERNAL_DIV		76
+#define CLK_UART0_DIV			77
+#define CLK_UART1_INTERNAL_DIV		78
+#define CLK_UART1_DIV			79
+#define CLK_SYS_INTERNAL_DIV		80
+#define CLK_SPI0_INTERNAL_DIV		81
+#define CLK_SPI0_DIV			82
+#define CLK_SPI1_INTERNAL_DIV		83
+#define CLK_SPI1_DIV			84
+#define CLK_EVENT_TIMER_INTERNAL_DIV	85
+#define CLK_EVENT_TIMER_DIV		86
+#define CLK_AUX_ADC_INTERNAL_DIV	87
+#define CLK_AUX_ADC_DIV			88
+#define CLK_SD_HOST_DIV			89
+#define CLK_BT_DIV			90
+#define CLK_BT_DIV4_DIV			91
+#define CLK_BT_DIV8_DIV			92
+#define CLK_BT_1MHZ_INTERNAL_DIV	93
+#define CLK_BT_1MHZ_DIV			94
+
+/* Mux clocks */
+#define CLK_AUDIO_REF_MUX		96
+#define CLK_MIPS_PLL_MUX		97
+#define CLK_AUDIO_PLL_MUX		98
+#define CLK_AUDIO_MUX			99
+#define CLK_RPU_V_PLL_MUX		100
+#define CLK_RPU_L_PLL_MUX		101
+#define CLK_RPU_L_MUX			102
+#define CLK_WIFI_PLL_MUX		103
+#define CLK_WIFI_DIV4_MUX		104
+#define CLK_WIFI_DIV8_MUX		105
+#define CLK_RPU_CORE_MUX		106
+#define CLK_SYS_PLL_MUX			107
+#define CLK_ENET_MUX			108
+#define CLK_EVENT_TIMER_MUX		109
+#define CLK_SD_HOST_MUX			110
+#define CLK_BT_PLL_MUX			111
+#define CLK_DEBUG_MUX			112
+
+#define CLK_NR_CLKS			113
+
+/* Peripheral gate clocks */
+#define PERIPH_CLK_SYS			0
+#define PERIPH_CLK_SYS_BUS		1
+#define PERIPH_CLK_DDR			2
+#define PERIPH_CLK_ROM			3
+#define PERIPH_CLK_COUNTER_FAST		4
+#define PERIPH_CLK_COUNTER_SLOW		5
+#define PERIPH_CLK_IR			6
+#define PERIPH_CLK_WD			7
+#define PERIPH_CLK_PDM			8
+#define PERIPH_CLK_PWM			9
+#define PERIPH_CLK_I2C0			10
+#define PERIPH_CLK_I2C1			11
+#define PERIPH_CLK_I2C2			12
+#define PERIPH_CLK_I2C3			13
+
+/* Peripheral divider clocks */
+#define PERIPH_CLK_ROM_DIV		32
+#define PERIPH_CLK_COUNTER_FAST_DIV	33
+#define PERIPH_CLK_COUNTER_SLOW_PRE_DIV	34
+#define PERIPH_CLK_COUNTER_SLOW_DIV	35
+#define PERIPH_CLK_IR_PRE_DIV		36
+#define PERIPH_CLK_IR_DIV		37
+#define PERIPH_CLK_WD_PRE_DIV		38
+#define PERIPH_CLK_WD_DIV		39
+#define PERIPH_CLK_PDM_PRE_DIV		40
+#define PERIPH_CLK_PDM_DIV		41
+#define PERIPH_CLK_PWM_PRE_DIV		42
+#define PERIPH_CLK_PWM_DIV		43
+#define PERIPH_CLK_I2C0_PRE_DIV		44
+#define PERIPH_CLK_I2C0_DIV		45
+#define PERIPH_CLK_I2C1_PRE_DIV		46
+#define PERIPH_CLK_I2C1_DIV		47
+#define PERIPH_CLK_I2C2_PRE_DIV		48
+#define PERIPH_CLK_I2C2_DIV		49
+#define PERIPH_CLK_I2C3_PRE_DIV		50
+#define PERIPH_CLK_I2C3_DIV		51
+
+#define PERIPH_CLK_NR_CLKS		52
+
+/* System gate clocks */
+#define SYS_CLK_I2C0			0
+#define SYS_CLK_I2C1			1
+#define SYS_CLK_I2C2			2
+#define SYS_CLK_I2C3			3
+#define SYS_CLK_I2S_IN			4
+#define SYS_CLK_PAUD_OUT		5
+#define SYS_CLK_SPDIF_OUT		6
+#define SYS_CLK_SPI0_MASTER		7
+#define SYS_CLK_SPI0_SLAVE		8
+#define SYS_CLK_PWM			9
+#define SYS_CLK_UART0			10
+#define SYS_CLK_UART1			11
+#define SYS_CLK_SPI1			12
+#define SYS_CLK_MDC			13
+#define SYS_CLK_SD_HOST			14
+#define SYS_CLK_ENET			15
+#define SYS_CLK_IR			16
+#define SYS_CLK_WD			17
+#define SYS_CLK_TIMER			18
+#define SYS_CLK_I2S_OUT			24
+#define SYS_CLK_SPDIF_IN		25
+#define SYS_CLK_EVENT_TIMER		26
+#define SYS_CLK_HASH			27
+
+#define SYS_CLK_NR_CLKS			28
+
+/* Gates for external input clocks */
+#define EXT_CLK_AUDIO_IN		0
+#define EXT_CLK_ENET_IN			1
+
+#define EXT_CLK_NR_CLKS			2
+
+#endif /* _DT_BINDINGS_CLOCK_PISTACHIO_H */