Merge branch 'for-linus/i2c-2636' of git://git.fluff.org/bjdooks/linux

* 'for-linus/i2c-2636' of git://git.fluff.org/bjdooks/linux:
  i2c/nuc900: add i2c driver support for nuc900
  i2c: Enable NXP LPC support in Kconfig
  i2c-pxa: fix compiler warning, due to missing const
  i2c: davinci: bus recovery procedure to clear the bus
  i2c: davinci: Add cpufreq support
  i2c: davinci: Add suspend/resume support
  i2c: davinci: Add helper functions for power management
  i2c: davinci: misc. cleanups: remove MOD_REG_BIT and IO_ADDRESS usage
  i2c: davinci: Fix smbus Oops with AIC33 usage

arch/arm/mach-w90x900/include/mach/i2c.h

+#ifndef __ASM_ARCH_NUC900_I2C_H
+#define __ASM_ARCH_NUC900_I2C_H
+
+struct nuc900_platform_i2c {
+	int		bus_num;
+	unsigned long   bus_freq;
+};
+
+#endif /* __ASM_ARCH_NUC900_I2C_H */

drivers/i2c/busses/Kconfig

@@ -448,6 +448,13 @@ config I2C_NOMADIK
 	  If you say yes to this option, support will be included for the
 	  I2C interface from ST-Ericsson's Nomadik and Ux500 architectures.
 
+config I2C_NUC900
+	tristate "NUC900 I2C Driver"
+	depends on ARCH_W90X900
+	help
+	  Say Y here to include support for I2C controller in the
+	  Winbond/Nuvoton NUC900 based System-on-Chip devices.
+
 config I2C_OCORES
 	tristate "OpenCores I2C Controller"
 	depends on EXPERIMENTAL
@@ -496,8 +503,8 @@ config I2C_PMCMSP
 	  will be called i2c-pmcmsp.
 
 config I2C_PNX
-	tristate "I2C bus support for Philips PNX targets"
-	depends on ARCH_PNX4008
+	tristate "I2C bus support for Philips PNX and NXP LPC targets"
+	depends on ARCH_PNX4008 || ARCH_LPC32XX
 	help
 	  This driver supports the Philips IP3204 I2C IP block master and/or
 	  slave controller

drivers/i2c/busses/Makefile

@@ -43,6 +43,7 @@ obj-$(CONFIG_I2C_IXP2000)	+= i2c-ixp2000.o
 obj-$(CONFIG_I2C_MPC)		+= i2c-mpc.o
 obj-$(CONFIG_I2C_MV64XXX)	+= i2c-mv64xxx.o
 obj-$(CONFIG_I2C_NOMADIK)	+= i2c-nomadik.o
+obj-$(CONFIG_I2C_NUC900)	+= i2c-nuc900.o
 obj-$(CONFIG_I2C_OCORES)	+= i2c-ocores.o
 obj-$(CONFIG_I2C_OMAP)		+= i2c-omap.o
 obj-$(CONFIG_I2C_PASEMI)	+= i2c-pasemi.o

drivers/i2c/busses/i2c-davinci.c

@@ -36,14 +36,16 @@
 #include <linux/platform_device.h>
 #include <linux/io.h>
 #include <linux/slab.h>
+#include <linux/cpufreq.h>
+#include <linux/gpio.h>
 
 #include <mach/hardware.h>
-
 #include <mach/i2c.h>
 
 /* ----- global defines ----------------------------------------------- */
 
 #define DAVINCI_I2C_TIMEOUT	(1*HZ)
+#define DAVINCI_I2C_MAX_TRIES	2
 #define I2C_DAVINCI_INTR_ALL    (DAVINCI_I2C_IMR_AAS | \
 				 DAVINCI_I2C_IMR_SCD | \
 				 DAVINCI_I2C_IMR_ARDY | \
@@ -72,37 +74,29 @@
 #define DAVINCI_I2C_IVR_NACK	0x02
 #define DAVINCI_I2C_IVR_AL	0x01
 
-#define DAVINCI_I2C_STR_BB	(1 << 12)
-#define DAVINCI_I2C_STR_RSFULL	(1 << 11)
-#define DAVINCI_I2C_STR_SCD	(1 << 5)
-#define DAVINCI_I2C_STR_ARDY	(1 << 2)
-#define DAVINCI_I2C_STR_NACK	(1 << 1)
-#define DAVINCI_I2C_STR_AL	(1 << 0)
-
-#define DAVINCI_I2C_MDR_NACK	(1 << 15)
-#define DAVINCI_I2C_MDR_STT	(1 << 13)
-#define DAVINCI_I2C_MDR_STP	(1 << 11)
-#define DAVINCI_I2C_MDR_MST	(1 << 10)
-#define DAVINCI_I2C_MDR_TRX	(1 << 9)
-#define DAVINCI_I2C_MDR_XA	(1 << 8)
-#define DAVINCI_I2C_MDR_RM	(1 << 7)
-#define DAVINCI_I2C_MDR_IRS	(1 << 5)
-
-#define DAVINCI_I2C_IMR_AAS	(1 << 6)
-#define DAVINCI_I2C_IMR_SCD	(1 << 5)
-#define DAVINCI_I2C_IMR_XRDY	(1 << 4)
-#define DAVINCI_I2C_IMR_RRDY	(1 << 3)
-#define DAVINCI_I2C_IMR_ARDY	(1 << 2)
-#define DAVINCI_I2C_IMR_NACK	(1 << 1)
-#define DAVINCI_I2C_IMR_AL	(1 << 0)
-
-#define MOD_REG_BIT(val, mask, set) do { \
-	if (set) { \
-		val |= mask; \
-	} else { \
-		val &= ~mask; \
-	} \
-} while (0)
+#define DAVINCI_I2C_STR_BB	BIT(12)
+#define DAVINCI_I2C_STR_RSFULL	BIT(11)
+#define DAVINCI_I2C_STR_SCD	BIT(5)
+#define DAVINCI_I2C_STR_ARDY	BIT(2)
+#define DAVINCI_I2C_STR_NACK	BIT(1)
+#define DAVINCI_I2C_STR_AL	BIT(0)
+
+#define DAVINCI_I2C_MDR_NACK	BIT(15)
+#define DAVINCI_I2C_MDR_STT	BIT(13)
+#define DAVINCI_I2C_MDR_STP	BIT(11)
+#define DAVINCI_I2C_MDR_MST	BIT(10)
+#define DAVINCI_I2C_MDR_TRX	BIT(9)
+#define DAVINCI_I2C_MDR_XA	BIT(8)
+#define DAVINCI_I2C_MDR_RM	BIT(7)
+#define DAVINCI_I2C_MDR_IRS	BIT(5)
+
+#define DAVINCI_I2C_IMR_AAS	BIT(6)
+#define DAVINCI_I2C_IMR_SCD	BIT(5)
+#define DAVINCI_I2C_IMR_XRDY	BIT(4)
+#define DAVINCI_I2C_IMR_RRDY	BIT(3)
+#define DAVINCI_I2C_IMR_ARDY	BIT(2)
+#define DAVINCI_I2C_IMR_NACK	BIT(1)
+#define DAVINCI_I2C_IMR_AL	BIT(0)
 
 struct davinci_i2c_dev {
 	struct device           *dev;
@@ -113,8 +107,13 @@ struct davinci_i2c_dev {
 	u8			*buf;
 	size_t			buf_len;
 	int			irq;
+	int			stop;
 	u8			terminate;
 	struct i2c_adapter	adapter;
+#ifdef CONFIG_CPU_FREQ
+	struct completion	xfr_complete;
+	struct notifier_block	freq_transition;
+#endif
 };
 
 /* default platform data to use if not supplied in the platform_device */
@@ -134,12 +133,59 @@ static inline u16 davinci_i2c_read_reg(struct davinci_i2c_dev *i2c_dev, int reg)
 	return __raw_readw(i2c_dev->base + reg);
 }
 
-/*
- * This functions configures I2C and brings I2C out of reset.
- * This function is called during I2C init function. This function
- * also gets called if I2C encounters any errors.
+/* Generate a pulse on the i2c clock pin. */
+static void generic_i2c_clock_pulse(unsigned int scl_pin)
+{
+	u16 i;
+
+	if (scl_pin) {
+		/* Send high and low on the SCL line */
+		for (i = 0; i < 9; i++) {
+			gpio_set_value(scl_pin, 0);
+			udelay(20);
+			gpio_set_value(scl_pin, 1);
+			udelay(20);
+		}
+	}
+}
+
+/* This routine does i2c bus recovery as specified in the
+ * i2c protocol Rev. 03 section 3.16 titled "Bus clear"
  */
-static int i2c_davinci_init(struct davinci_i2c_dev *dev)
+static void i2c_recover_bus(struct davinci_i2c_dev *dev)
+{
+	u32 flag = 0;
+	struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
+
+	dev_err(dev->dev, "initiating i2c bus recovery\n");
+	/* Send NACK to the slave */
+	flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
+	flag |=  DAVINCI_I2C_MDR_NACK;
+	/* write the data into mode register */
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
+	if (pdata)
+		generic_i2c_clock_pulse(pdata->scl_pin);
+	/* Send STOP */
+	flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
+	flag |= DAVINCI_I2C_MDR_STP;
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
+}
+
+static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev,
+								int val)
+{
+	u16 w;
+
+	w = davinci_i2c_read_reg(i2c_dev, DAVINCI_I2C_MDR_REG);
+	if (!val)	/* put I2C into reset */
+		w &= ~DAVINCI_I2C_MDR_IRS;
+	else		/* take I2C out of reset */
+		w |= DAVINCI_I2C_MDR_IRS;
+
+	davinci_i2c_write_reg(i2c_dev, DAVINCI_I2C_MDR_REG, w);
+}
+
+static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
 {
 	struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
 	u16 psc;
@@ -148,15 +194,6 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
 	u32 clkh;
 	u32 clkl;
 	u32 input_clock = clk_get_rate(dev->clk);
-	u16 w;
-
-	if (!pdata)
-		pdata = &davinci_i2c_platform_data_default;
-
-	/* put I2C into reset */
-	w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
-	MOD_REG_BIT(w, DAVINCI_I2C_MDR_IRS, 0);
-	davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
 
 	/* NOTE: I2C Clock divider programming info
 	 * As per I2C specs the following formulas provide prescaler
@@ -188,12 +225,32 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
 	davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKH_REG, clkh);
 	davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKL_REG, clkl);
 
+	dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk);
+}
+
+/*
+ * This function configures I2C and brings I2C out of reset.
+ * This function is called during I2C init function. This function
+ * also gets called if I2C encounters any errors.
+ */
+static int i2c_davinci_init(struct davinci_i2c_dev *dev)
+{
+	struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
+
+	if (!pdata)
+		pdata = &davinci_i2c_platform_data_default;
+
+	/* put I2C into reset */
+	davinci_i2c_reset_ctrl(dev, 0);
+
+	/* compute clock dividers */
+	i2c_davinci_calc_clk_dividers(dev);
+
 	/* Respond at reserved "SMBus Host" slave address" (and zero);
 	 * we seem to have no option to not respond...
 	 */
 	davinci_i2c_write_reg(dev, DAVINCI_I2C_OAR_REG, 0x08);
 
-	dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk);
 	dev_dbg(dev->dev, "PSC  = %d\n",
 		davinci_i2c_read_reg(dev, DAVINCI_I2C_PSC_REG));
 	dev_dbg(dev->dev, "CLKL = %d\n",
@@ -204,9 +261,7 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
 		pdata->bus_freq, pdata->bus_delay);
 
 	/* Take the I2C module out of reset: */
-	w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
-	MOD_REG_BIT(w, DAVINCI_I2C_MDR_IRS, 1);
-	davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
+	davinci_i2c_reset_ctrl(dev, 1);
 
 	/* Enable interrupts */
 	davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, I2C_DAVINCI_INTR_ALL);
@@ -221,14 +276,22 @@ static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev,
 					 char allow_sleep)
 {
 	unsigned long timeout;
+	static u16 to_cnt;
 
 	timeout = jiffies + dev->adapter.timeout;
 	while (davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG)
 	       & DAVINCI_I2C_STR_BB) {
-		if (time_after(jiffies, timeout)) {
-			dev_warn(dev->dev,
-				 "timeout waiting for bus ready\n");
-			return -ETIMEDOUT;
+		if (to_cnt <= DAVINCI_I2C_MAX_TRIES) {
+			if (time_after(jiffies, timeout)) {
+				dev_warn(dev->dev,
+				"timeout waiting for bus ready\n");
+				to_cnt++;
+				return -ETIMEDOUT;
+			} else {
+				to_cnt = 0;
+				i2c_recover_bus(dev);
+				i2c_davinci_init(dev);
+			}
 		}
 		if (allow_sleep)
 			schedule_timeout(1);
@@ -250,9 +313,6 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
 	u16 w;
 	int r;
 
-	if (msg->len == 0)
-		return -EINVAL;
-
 	if (!pdata)
 		pdata = &davinci_i2c_platform_data_default;
 	/* Introduce a delay, required for some boards (e.g Davinci EVM) */
@@ -264,6 +324,7 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
 
 	dev->buf = msg->buf;
 	dev->buf_len = msg->len;
+	dev->stop = stop;
 
 	davinci_i2c_write_reg(dev, DAVINCI_I2C_CNT_REG, dev->buf_len);
 
@@ -281,23 +342,40 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
 		flag |= DAVINCI_I2C_MDR_TRX;
 	if (stop)
 		flag |= DAVINCI_I2C_MDR_STP;
+	if (msg->len == 0) {
+		flag |= DAVINCI_I2C_MDR_RM;
+		flag &= ~DAVINCI_I2C_MDR_STP;
+	}
 
 	/* Enable receive or transmit interrupts */
 	w = davinci_i2c_read_reg(dev, DAVINCI_I2C_IMR_REG);
 	if (msg->flags & I2C_M_RD)
-		MOD_REG_BIT(w, DAVINCI_I2C_IMR_RRDY, 1);
+		w |= DAVINCI_I2C_IMR_RRDY;
 	else
-		MOD_REG_BIT(w, DAVINCI_I2C_IMR_XRDY, 1);
+		w |= DAVINCI_I2C_IMR_XRDY;
 	davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, w);
 
 	dev->terminate = 0;
+
 	/* write the data into mode register */
 	davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
 
+	/*
+	 * First byte should be set here, not after interrupt,
+	 * because transmit-data-ready interrupt can come before
+	 * NACK-interrupt during sending of previous message and
+	 * ICDXR may have wrong data
+	 */
+	if ((!(msg->flags & I2C_M_RD)) && dev->buf_len) {
+		davinci_i2c_write_reg(dev, DAVINCI_I2C_DXR_REG, *dev->buf++);
+		dev->buf_len--;
+	}
+
 	r = wait_for_completion_interruptible_timeout(&dev->cmd_complete,
 						      dev->adapter.timeout);
 	if (r == 0) {
 		dev_err(dev->dev, "controller timed out\n");
+		i2c_recover_bus(dev);
 		i2c_davinci_init(dev);
 		dev->buf_len = 0;
 		return -ETIMEDOUT;
@@ -334,7 +412,7 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
 			return msg->len;
 		if (stop) {
 			w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
-			MOD_REG_BIT(w, DAVINCI_I2C_MDR_STP, 1);
+			w |= DAVINCI_I2C_MDR_STP;
 			davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
 		}
 		return -EREMOTEIO;
@@ -367,12 +445,17 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 		if (ret < 0)
 			return ret;
 	}
+
+#ifdef CONFIG_CPU_FREQ
+	complete(&dev->xfr_complete);
+#endif
+
 	return num;
 }
 
 static u32 i2c_davinci_func(struct i2c_adapter *adap)
 {
-	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 }
 
 static void terminate_read(struct davinci_i2c_dev *dev)
@@ -431,6 +514,14 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
 		case DAVINCI_I2C_IVR_ARDY:
 			davinci_i2c_write_reg(dev,
 				DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_ARDY);
+			if (((dev->buf_len == 0) && (dev->stop != 0)) ||
+			    (dev->cmd_err & DAVINCI_I2C_STR_NACK)) {
+				w = davinci_i2c_read_reg(dev,
+							 DAVINCI_I2C_MDR_REG);
+				w |= DAVINCI_I2C_MDR_STP;
+				davinci_i2c_write_reg(dev,
+						      DAVINCI_I2C_MDR_REG, w);
+			}
 			complete(&dev->cmd_complete);
 			break;
 
@@ -462,7 +553,7 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
 
 				w = davinci_i2c_read_reg(dev,
 							 DAVINCI_I2C_IMR_REG);
-				MOD_REG_BIT(w, DAVINCI_I2C_IMR_XRDY, 0);
+				w &= ~DAVINCI_I2C_IMR_XRDY;
 				davinci_i2c_write_reg(dev,
 						      DAVINCI_I2C_IMR_REG,
 						      w);
@@ -491,6 +582,48 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
 	return count ? IRQ_HANDLED : IRQ_NONE;
 }
 
+#ifdef CONFIG_CPU_FREQ
+static int i2c_davinci_cpufreq_transition(struct notifier_block *nb,
+				     unsigned long val, void *data)
+{
+	struct davinci_i2c_dev *dev;
+
+	dev = container_of(nb, struct davinci_i2c_dev, freq_transition);
+	if (val == CPUFREQ_PRECHANGE) {
+		wait_for_completion(&dev->xfr_complete);
+		davinci_i2c_reset_ctrl(dev, 0);
+	} else if (val == CPUFREQ_POSTCHANGE) {
+		i2c_davinci_calc_clk_dividers(dev);
+		davinci_i2c_reset_ctrl(dev, 1);
+	}
+
+	return 0;
+}
+
+static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev)
+{
+	dev->freq_transition.notifier_call = i2c_davinci_cpufreq_transition;
+
+	return cpufreq_register_notifier(&dev->freq_transition,
+					 CPUFREQ_TRANSITION_NOTIFIER);
+}
+
+static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev)
+{
+	cpufreq_unregister_notifier(&dev->freq_transition,
+				    CPUFREQ_TRANSITION_NOTIFIER);
+}
+#else
+static inline int i2c_davinci_cpufreq_register(struct davinci_i2c_dev *dev)
+{
+	return 0;
+}
+
+static inline void i2c_davinci_cpufreq_deregister(struct davinci_i2c_dev *dev)
+{
+}
+#endif
+
 static struct i2c_algorithm i2c_davinci_algo = {
 	.master_xfer	= i2c_davinci_xfer,
 	.functionality	= i2c_davinci_func,
@@ -530,6 +663,9 @@ static int davinci_i2c_probe(struct platform_device *pdev)
 	}
 
 	init_completion(&dev->cmd_complete);
+#ifdef CONFIG_CPU_FREQ
+	init_completion(&dev->xfr_complete);
+#endif
 	dev->dev = get_device(&pdev->dev);
 	dev->irq = irq->start;
 	platform_set_drvdata(pdev, dev);
@@ -541,7 +677,12 @@ static int davinci_i2c_probe(struct platform_device *pdev)
 	}
 	clk_enable(dev->clk);
 
-	dev->base = (void __iomem *)IO_ADDRESS(mem->start);
+	dev->base = ioremap(mem->start, resource_size(mem));
+	if (!dev->base) {
+		r = -EBUSY;
+		goto err_mem_ioremap;
+	}
+
 	i2c_davinci_init(dev);
 
 	r = request_irq(dev->irq, i2c_davinci_isr, 0, pdev->name, dev);
@@ -550,6 +691,12 @@ static int davinci_i2c_probe(struct platform_device *pdev)
 		goto err_unuse_clocks;
 	}
 
+	r = i2c_davinci_cpufreq_register(dev);
+	if (r) {
+		dev_err(&pdev->dev, "failed to register cpufreq\n");
+		goto err_free_irq;
+	}
+
 	adap = &dev->adapter;
 	i2c_set_adapdata(adap, dev);
 	adap->owner = THIS_MODULE;
@@ -571,6 +718,8 @@ static int davinci_i2c_probe(struct platform_device *pdev)
 err_free_irq:
 	free_irq(dev->irq, dev);
 err_unuse_clocks:
+	iounmap(dev->base);
+err_mem_ioremap:
 	clk_disable(dev->clk);
 	clk_put(dev->clk);
 	dev->clk = NULL;
@@ -589,6 +738,8 @@ static int davinci_i2c_remove(struct platform_device *pdev)
 	struct davinci_i2c_dev *dev = platform_get_drvdata(pdev);
 	struct resource *mem;
 
+	i2c_davinci_cpufreq_deregister(dev);
+
 	platform_set_drvdata(pdev, NULL);
 	i2c_del_adapter(&dev->adapter);
 	put_device(&pdev->dev);
@@ -599,6 +750,7 @@ static int davinci_i2c_remove(struct platform_device *pdev)
 
 	davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, 0);
 	free_irq(IRQ_I2C, dev);
+	iounmap(dev->base);
 	kfree(dev);
 
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -606,6 +758,41 @@ static int davinci_i2c_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_PM
+static int davinci_i2c_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct davinci_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
+
+	/* put I2C into reset */
+	davinci_i2c_reset_ctrl(i2c_dev, 0);
+	clk_disable(i2c_dev->clk);
+
+	return 0;
+}
+
+static int davinci_i2c_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct davinci_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
+
+	clk_enable(i2c_dev->clk);
+	/* take I2C out of reset */
+	davinci_i2c_reset_ctrl(i2c_dev, 1);
+
+	return 0;
+}
+
+static const struct dev_pm_ops davinci_i2c_pm = {
+	.suspend        = davinci_i2c_suspend,
+	.resume         = davinci_i2c_resume,
+};
+
+#define davinci_i2c_pm_ops (&davinci_i2c_pm)
+#else
+#define davinci_i2c_pm_ops NULL
+#endif
+
 /* work with hotplug and coldplug */
 MODULE_ALIAS("platform:i2c_davinci");
 
@@ -615,6 +802,7 @@ static struct platform_driver davinci_i2c_driver = {
 	.driver		= {
 		.name	= "i2c_davinci",
 		.owner	= THIS_MODULE,
+		.pm	= davinci_i2c_pm_ops,
 	},
 };
 

drivers/i2c/busses/i2c-nuc900.c

+/*
+ * linux/drivers/i2c/busses/i2c-nuc900.c
+ *
+ * Copyright (c) 2010 Nuvoton technology corporation.
+ *
+ * This driver based on S3C2410 I2C driver of Ben Dooks <ben-Y5A6D6n0/KfQXOPxS62xeg@public.gmane.org>.
+ * Written by Wan ZongShun <mcuos.com-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation;version 2 of the License.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <linux/i2c.h>
+#include <linux/i2c-id.h>
+#include <linux/init.h>
+#include <linux/time.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/cpufreq.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+
+#include <mach/mfp.h>
+#include <mach/i2c.h>
+
+/* nuc900 i2c registers offset */
+
+#define CSR		0x00
+#define DIVIDER		0x04
+#define CMDR		0x08
+#define SWR		0x0C
+#define RXR		0x10
+#define TXR		0x14
+
+/* nuc900 i2c CSR register bits */
+
+#define IRQEN		0x003
+#define I2CBUSY		0x400
+#define I2CSTART	0x018
+#define IRQFLAG		0x004
+#define ARBIT_LOST	0x200
+#define SLAVE_ACK	0x800
+
+/* nuc900 i2c CMDR register bits */
+
+#define I2C_CMD_START	0x10
+#define I2C_CMD_STOP	0x08
+#define I2C_CMD_READ	0x04
+#define I2C_CMD_WRITE	0x02
+#define I2C_CMD_NACK	0x01
+
+/* i2c controller state */
+
+enum nuc900_i2c_state {
+	STATE_IDLE,
+	STATE_START,
+	STATE_READ,
+	STATE_WRITE,
+	STATE_STOP
+};
+
+/* i2c controller private data */
+
+struct nuc900_i2c {
+	spinlock_t		lock;
+	wait_queue_head_t	wait;
+
+	struct i2c_msg		*msg;
+	unsigned int		msg_num;
+	unsigned int		msg_idx;
+	unsigned int		msg_ptr;
+	unsigned int		irq;
+
+	enum nuc900_i2c_state	state;
+
+	void __iomem		*regs;
+	struct clk		*clk;
+	struct device		*dev;
+	struct resource		*ioarea;
+	struct i2c_adapter	adap;
+};
+
+/* nuc900_i2c_master_complete
+ *
+ * complete the message and wake up the caller, using the given return code,
+ * or zero to mean ok.
+*/
+
+static inline void nuc900_i2c_master_complete(struct nuc900_i2c *i2c, int ret)
+{
+	dev_dbg(i2c->dev, "master_complete %d\n", ret);
+
+	i2c->msg_ptr = 0;
+	i2c->msg = NULL;
+	i2c->msg_idx++;
+	i2c->msg_num = 0;
+	if (ret)
+		i2c->msg_idx = ret;
+
+	wake_up(&i2c->wait);
+}
+
+/* irq enable/disable functions */
+
+static inline void nuc900_i2c_disable_irq(struct nuc900_i2c *i2c)
+{
+	unsigned long tmp;
+
+	tmp = readl(i2c->regs + CSR);
+	writel(tmp & ~IRQEN, i2c->regs + CSR);
+}
+
+static inline void nuc900_i2c_enable_irq(struct nuc900_i2c *i2c)
+{
+	unsigned long tmp;
+
+	tmp = readl(i2c->regs + CSR);
+	writel(tmp | IRQEN, i2c->regs + CSR);
+}
+
+
+/* nuc900_i2c_message_start
+ *
+ * put the start of a message onto the bus
+*/
+
+static void nuc900_i2c_message_start(struct nuc900_i2c *i2c,
+				      struct i2c_msg *msg)
+{
+	unsigned int addr = (msg->addr & 0x7f) << 1;
+
+	if (msg->flags & I2C_M_RD)
+		addr |= 0x1;
+	writel(addr & 0xff, i2c->regs + TXR);
+	writel(I2C_CMD_START | I2C_CMD_WRITE, i2c->regs + CMDR);
+}
+
+static inline void nuc900_i2c_stop(struct nuc900_i2c *i2c, int ret)
+{
+
+	dev_dbg(i2c->dev, "STOP\n");
+
+	/* stop the transfer */
+	i2c->state = STATE_STOP;
+	writel(I2C_CMD_STOP, i2c->regs + CMDR);
+
+	nuc900_i2c_master_complete(i2c, ret);
+	nuc900_i2c_disable_irq(i2c);
+}
+
+/* helper functions to determine the current state in the set of
+ * messages we are sending
+*/
+
+/* is_lastmsg()
+ *
+ * returns TRUE if the current message is the last in the set
+*/
+
+static inline int is_lastmsg(struct nuc900_i2c *i2c)
+{
+	return i2c->msg_idx >= (i2c->msg_num - 1);
+}
+
+/* is_msglast
+ *
+ * returns TRUE if we this is the last byte in the current message
+*/
+
+static inline int is_msglast(struct nuc900_i2c *i2c)
+{
+	return i2c->msg_ptr == i2c->msg->len-1;
+}
+
+/* is_msgend
+ *
+ * returns TRUE if we reached the end of the current message
+*/
+
+static inline int is_msgend(struct nuc900_i2c *i2c)
+{
+	return i2c->msg_ptr >= i2c->msg->len;
+}
+
+/* i2c_nuc900_irq_nextbyte
+ *
+ * process an interrupt and work out what to do
+ */
+
+static void i2c_nuc900_irq_nextbyte(struct nuc900_i2c *i2c,
+							unsigned long iicstat)
+{
+	unsigned char byte;
+
+	switch (i2c->state) {
+
+	case STATE_IDLE:
+		dev_err(i2c->dev, "%s: called in STATE_IDLE\n", __func__);
+		break;
+
+	case STATE_STOP:
+		dev_err(i2c->dev, "%s: called in STATE_STOP\n", __func__);
+		nuc900_i2c_disable_irq(i2c);
+		break;
+
+	case STATE_START:
+		/* last thing we did was send a start condition on the
+		 * bus, or started a new i2c message
+		 */
+
+		if (iicstat & SLAVE_ACK &&
+		    !(i2c->msg->flags & I2C_M_IGNORE_NAK)) {
+			/* ack was not received... */
+
+			dev_dbg(i2c->dev, "ack was not received\n");
+			nuc900_i2c_stop(i2c, -ENXIO);
+			break;
+		}
+
+		if (i2c->msg->flags & I2C_M_RD)
+			i2c->state = STATE_READ;
+		else
+			i2c->state = STATE_WRITE;
+
+		/* terminate the transfer if there is nothing to do
+		 * as this is used by the i2c probe to find devices.
+		*/
+
+		if (is_lastmsg(i2c) && i2c->msg->len == 0) {
+			nuc900_i2c_stop(i2c, 0);
+			break;
+		}
+
+		if (i2c->state == STATE_READ)
+			goto prepare_read;
+
+		/* fall through to the write state, as we will need to
+		 * send a byte as well
+		*/
+
+	case STATE_WRITE:
+		/* we are writing data to the device... check for the
+		 * end of the message, and if so, work out what to do
+		 */
+
+		if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) {
+			if (iicstat & SLAVE_ACK) {
+				dev_dbg(i2c->dev, "WRITE: No Ack\n");
+
+				nuc900_i2c_stop(i2c, -ECONNREFUSED);
+				break;
+			}
+		}
+
+retry_write:
+
+		if (!is_msgend(i2c)) {
+			byte = i2c->msg->buf[i2c->msg_ptr++];
+			writeb(byte, i2c->regs + TXR);
+			writel(I2C_CMD_WRITE, i2c->regs + CMDR);
+
+		} else if (!is_lastmsg(i2c)) {
+			/* we need to go to the next i2c message */
+
+			dev_dbg(i2c->dev, "WRITE: Next Message\n");
+
+			i2c->msg_ptr = 0;
+			i2c->msg_idx++;
+			i2c->msg++;
+
+			/* check to see if we need to do another message */
+			if (i2c->msg->flags & I2C_M_NOSTART) {
+
+				if (i2c->msg->flags & I2C_M_RD) {
+					/* cannot do this, the controller
+					 * forces us to send a new START
+					 * when we change direction
+					*/
+
+					nuc900_i2c_stop(i2c, -EINVAL);
+				}
+
+				goto retry_write;
+			} else {
+				/* send the new start */
+				nuc900_i2c_message_start(i2c, i2c->msg);
+				i2c->state = STATE_START;
+			}
+
+		} else {
+			/* send stop */
+
+			nuc900_i2c_stop(i2c, 0);
+		}
+		break;
+
+	case STATE_READ:
+		/* we have a byte of data in the data register, do
+		 * something with it, and then work out wether we are
+		 * going to do any more read/write
+		 */
+
+		byte = readb(i2c->regs + RXR);
+		i2c->msg->buf[i2c->msg_ptr++] = byte;
+
+prepare_read:
+		if (is_msglast(i2c)) {
+			/* last byte of buffer */
+
+			if (is_lastmsg(i2c))
+				writel(I2C_CMD_READ | I2C_CMD_NACK,
+							i2c->regs + CMDR);
+
+		} else if (is_msgend(i2c)) {
+			/* ok, we've read the entire buffer, see if there
+			 * is anything else we need to do
+			*/
+
+			if (is_lastmsg(i2c)) {
+				/* last message, send stop and complete */
+				dev_dbg(i2c->dev, "READ: Send Stop\n");
+
+				nuc900_i2c_stop(i2c, 0);
+			} else {
+				/* go to the next transfer */
+				dev_dbg(i2c->dev, "READ: Next Transfer\n");
+
+				i2c->msg_ptr = 0;
+				i2c->msg_idx++;
+				i2c->msg++;
+
+				writel(I2C_CMD_READ, i2c->regs + CMDR);
+			}
+
+		} else {
+			writel(I2C_CMD_READ, i2c->regs + CMDR);
+		}
+
+		break;
+	}
+}
+
+/* nuc900_i2c_irq
+ *
+ * top level IRQ servicing routine
+*/
+
+static irqreturn_t nuc900_i2c_irq(int irqno, void *dev_id)
+{
+	struct nuc900_i2c *i2c = dev_id;
+	unsigned long status;
+
+	status = readl(i2c->regs + CSR);
+	writel(status | IRQFLAG, i2c->regs + CSR);
+
+	if (status & ARBIT_LOST) {
+		/* deal with arbitration loss */
+		dev_err(i2c->dev, "deal with arbitration loss\n");
+		goto out;
+	}
+
+	if (i2c->state == STATE_IDLE) {
+		dev_dbg(i2c->dev, "IRQ: error i2c->state == IDLE\n");
+		goto out;
+	}
+
+	/* pretty much this leaves us with the fact that we've
+	 * transmitted or received whatever byte we last sent
+	*/
+
+	i2c_nuc900_irq_nextbyte(i2c, status);
+
+ out:
+	return IRQ_HANDLED;
+}
+
+
+/* nuc900_i2c_set_master
+ *
+ * get the i2c bus for a master transaction
+*/
+
+static int nuc900_i2c_set_master(struct nuc900_i2c *i2c)
+{
+	int timeout = 400;
+
+	while (timeout-- > 0) {
+		if (((readl(i2c->regs + SWR) & I2CSTART) == I2CSTART) &&
+				((readl(i2c->regs + CSR) & I2CBUSY) == 0)) {
+			return 0;
+		}
+
+		msleep(1);
+	}
+
+	return -ETIMEDOUT;
+}
+
+/* nuc900_i2c_doxfer
+ *
+ * this starts an i2c transfer
+*/
+
+static int nuc900_i2c_doxfer(struct nuc900_i2c *i2c,
+			      struct i2c_msg *msgs, int num)
+{
+	unsigned long iicstat, timeout;
+	int spins = 20;
+	int ret;
+
+	ret = nuc900_i2c_set_master(i2c);
+	if (ret != 0) {
+		dev_err(i2c->dev, "cannot get bus (error %d)\n", ret);
+		ret = -EAGAIN;
+		goto out;
+	}
+
+	spin_lock_irq(&i2c->lock);
+
+	i2c->msg     = msgs;
+	i2c->msg_num = num;
+	i2c->msg_ptr = 0;
+	i2c->msg_idx = 0;
+	i2c->state   = STATE_START;
+
+	nuc900_i2c_message_start(i2c, msgs);
+	spin_unlock_irq(&i2c->lock);
+
+	timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
+
+	ret = i2c->msg_idx;
+
+	/* having these next two as dev_err() makes life very
+	 * noisy when doing an i2cdetect
+	*/
+
+	if (timeout == 0)
+		dev_dbg(i2c->dev, "timeout\n");
+	else if (ret != num)
+		dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret);
+
+	/* ensure the stop has been through the bus */
+
+	dev_dbg(i2c->dev, "waiting for bus idle\n");
+
+	/* first, try busy waiting briefly */
+	do {
+		iicstat = readl(i2c->regs + CSR);
+	} while ((iicstat & I2CBUSY) && --spins);
+
+	/* if that timed out sleep */
+	if (!spins) {
+		msleep(1);
+		iicstat = readl(i2c->regs + CSR);
+	}
+
+	if (iicstat & I2CBUSY)
+		dev_warn(i2c->dev, "timeout waiting for bus idle\n");
+
+ out:
+	return ret;
+}
+
+/* nuc900_i2c_xfer
+ *
+ * first port of call from the i2c bus code when an message needs
+ * transferring across the i2c bus.
+*/
+
+static int nuc900_i2c_xfer(struct i2c_adapter *adap,
+			struct i2c_msg *msgs, int num)
+{
+	struct nuc900_i2c *i2c = (struct nuc900_i2c *)adap->algo_data;
+	int retry;
+	int ret;
+
+	nuc900_i2c_enable_irq(i2c);
+
+	for (retry = 0; retry < adap->retries; retry++) {
+
+		ret = nuc900_i2c_doxfer(i2c, msgs, num);
+
+		if (ret != -EAGAIN)
+			return ret;
+
+		dev_dbg(i2c->dev, "Retrying transmission (%d)\n", retry);
+
+		udelay(100);
+	}
+
+	return -EREMOTEIO;
+}
+
+/* declare our i2c functionality */
+static u32 nuc900_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING;
+}
+
+/* i2c bus registration info */
+
+static const struct i2c_algorithm nuc900_i2c_algorithm = {
+	.master_xfer		= nuc900_i2c_xfer,
+	.functionality		= nuc900_i2c_func,
+};
+
+/* nuc900_i2c_probe
+ *
+ * called by the bus driver when a suitable device is found
+*/
+
+static int __devinit nuc900_i2c_probe(struct platform_device *pdev)
+{
+	struct nuc900_i2c *i2c;
+	struct nuc900_platform_i2c *pdata;
+	struct resource *res;
+	int ret;
+
+	pdata = pdev->dev.platform_data;
+	if (!pdata) {
+		dev_err(&pdev->dev, "no platform data\n");
+		return -EINVAL;
+	}
+
+	i2c = kzalloc(sizeof(struct nuc900_i2c), GFP_KERNEL);
+	if (!i2c) {
+		dev_err(&pdev->dev, "no memory for state\n");
+		return -ENOMEM;
+	}
+
+	strlcpy(i2c->adap.name, "nuc900-i2c0", sizeof(i2c->adap.name));
+	i2c->adap.owner   = THIS_MODULE;
+	i2c->adap.algo    = &nuc900_i2c_algorithm;
+	i2c->adap.retries = 2;
+	i2c->adap.class   = I2C_CLASS_HWMON | I2C_CLASS_SPD;
+
+	spin_lock_init(&i2c->lock);
+	init_waitqueue_head(&i2c->wait);
+
+	/* find the clock and enable it */
+
+	i2c->dev = &pdev->dev;
+	i2c->clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(i2c->clk)) {
+		dev_err(&pdev->dev, "cannot get clock\n");
+		ret = -ENOENT;
+		goto err_noclk;
+	}
+
+	dev_dbg(&pdev->dev, "clock source %p\n", i2c->clk);
+
+	clk_enable(i2c->clk);
+
+	/* map the registers */
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (res == NULL) {
+		dev_err(&pdev->dev, "cannot find IO resource\n");
+		ret = -ENOENT;
+		goto err_clk;
+	}
+
+	i2c->ioarea = request_mem_region(res->start, resource_size(res),
+					 pdev->name);
+
+	if (i2c->ioarea == NULL) {
+		dev_err(&pdev->dev, "cannot request IO\n");
+		ret = -ENXIO;
+		goto err_clk;
+	}
+
+	i2c->regs = ioremap(res->start, resource_size(res));
+
+	if (i2c->regs == NULL) {
+		dev_err(&pdev->dev, "cannot map IO\n");
+		ret = -ENXIO;
+		goto err_ioarea;
+	}
+
+	dev_dbg(&pdev->dev, "registers %p (%p, %p)\n",
+		i2c->regs, i2c->ioarea, res);
+
+	/* setup info block for the i2c core */
+
+	i2c->adap.algo_data = i2c;
+	i2c->adap.dev.parent = &pdev->dev;
+
+	mfp_set_groupg(&pdev->dev);
+
+	clk_get_rate(i2c->clk);
+
+	ret = (i2c->clk.apbfreq)/(pdata->bus_freq * 5) - 1;
+	writel(ret & 0xffff, i2c->regs + DIVIDER);
+
+	/* find the IRQ for this unit (note, this relies on the init call to
+	 * ensure no current IRQs pending
+	 */
+
+	i2c->irq = ret = platform_get_irq(pdev, 0);
+	if (ret <= 0) {
+		dev_err(&pdev->dev, "cannot find IRQ\n");
+		goto err_iomap;
+	}
+
+	ret = request_irq(i2c->irq, nuc900_i2c_irq, IRQF_DISABLED | IRQF_SHARED,
+			  dev_name(&pdev->dev), i2c);
+
+	if (ret != 0) {
+		dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq);
+		goto err_iomap;
+	}
+
+	/* Note, previous versions of the driver used i2c_add_adapter()
+	 * to add the bus at any number. We now pass the bus number via
+	 * the platform data, so if unset it will now default to always
+	 * being bus 0.
+	 */
+
+	i2c->adap.nr = pdata->bus_num;
+
+	ret = i2c_add_numbered_adapter(&i2c->adap);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to add bus to i2c core\n");
+		goto err_irq;
+	}
+
+	platform_set_drvdata(pdev, i2c);
+
+	dev_info(&pdev->dev, "%s: NUC900 I2C adapter\n",
+						dev_name(&i2c->adap.dev));
+	return 0;
+
+ err_irq:
+	free_irq(i2c->irq, i2c);
+
+ err_iomap:
+	iounmap(i2c->regs);
+
+ err_ioarea:
+	release_resource(i2c->ioarea);
+	kfree(i2c->ioarea);
+
+ err_clk:
+	clk_disable(i2c->clk);
+	clk_put(i2c->clk);
+
+ err_noclk:
+	kfree(i2c);
+	return ret;
+}
+
+/* nuc900_i2c_remove
+ *
+ * called when device is removed from the bus
+*/
+
+static int __devexit nuc900_i2c_remove(struct platform_device *pdev)
+{
+	struct nuc900_i2c *i2c = platform_get_drvdata(pdev);
+
+	i2c_del_adapter(&i2c->adap);
+	free_irq(i2c->irq, i2c);
+
+	clk_disable(i2c->clk);
+	clk_put(i2c->clk);
+
+	iounmap(i2c->regs);
+
+	release_resource(i2c->ioarea);
+	kfree(i2c->ioarea);
+	kfree(i2c);
+
+	return 0;
+}
+
+static struct platform_driver nuc900_i2c_driver = {
+	.probe		= nuc900_i2c_probe,
+	.remove		= __devexit_p(nuc900_i2c_remove),
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= "nuc900-i2c0",
+	},
+};
+
+static int __init i2c_adap_nuc900_init(void)
+{
+	return platform_driver_register(&nuc900_i2c_driver);
+}
+
+static void __exit i2c_adap_nuc900_exit(void)
+{
+	platform_driver_unregister(&nuc900_i2c_driver);
+}
+subsys_initcall(i2c_adap_nuc900_init);
+module_exit(i2c_adap_nuc900_exit);
+
+MODULE_DESCRIPTION("NUC900 I2C Bus driver");
+MODULE_AUTHOR("Wan ZongShun, <mcuos.com-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:nuc900-i2c0");

drivers/i2c/busses/i2c-pxa.c

@@ -1001,7 +1001,7 @@ static int i2c_pxa_probe(struct platform_device *dev)
 	struct pxa_i2c *i2c;
 	struct resource *res;
 	struct i2c_pxa_platform_data *plat = dev->dev.platform_data;
-	struct platform_device_id *id = platform_get_device_id(dev);
+	const struct platform_device_id *id = platform_get_device_id(dev);
 	int ret;
 	int irq;