6 files changed, 980 insertions, 66 deletions

diff --git a/arch/arm/mach-w90x900/include/mach/i2c.h b/arch/arm/mach-w90x900/include/mach/i2c.h
new file mode 100644
index 000000000000..9ffb12d06e91
--- /dev/null
+++ b/arch/arm/mach-w90x900/include/mach/i2c.h
@@ -0,0 +1,9 @@
+#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 */
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 15a9702e2941..6539ac2907e9 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/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
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 936880bd1dc5..c3ef49230cba 100644
--- a/drivers/i2c/busses/Makefile
+++ b/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
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index 4523364e6722..2222c87876b9 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/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,
         },
 };
 
diff --git a/drivers/i2c/busses/i2c-nuc900.c b/drivers/i2c/busses/i2c-nuc900.c
new file mode 100644
index 000000000000..92d770d7bbc2
--- /dev/null
+++ b/drivers/i2c/busses/i2c-nuc900.c
@@ -0,0 +1,709 @@
+/*
+ * 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");
diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index 020ff23d762f..c94e51b2651e 100644
--- a/drivers/i2c/busses/i2c-pxa.c
+++ b/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;