1 files changed, 201 insertions, 101 deletions

diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c
index 73de8ade10b1..0c731ca69f15 100644
--- a/drivers/i2c/busses/i2c-nomadik.c
+++ b/drivers/i2c/busses/i2c-nomadik.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2009 ST-Ericsson
+ * Copyright (C) 2009 ST-Ericsson SA
  * Copyright (C) 2009 STMicroelectronics
  *
  * I2C master mode controller driver, used in Nomadik 8815
@@ -15,13 +15,14 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
-#include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/interrupt.h>
 #include <linux/i2c.h>
 #include <linux/err.h>
 #include <linux/clk.h>
 #include <linux/io.h>
+#include <linux/regulator/consumer.h>
+#include <linux/pm_runtime.h>
 
 #include <plat/i2c.h>
 
@@ -117,15 +118,12 @@ enum i2c_operation {
         I2C_READ = 0x01
 };
 
-/* controller response timeout in ms */
-#define I2C_TIMEOUT_MS  500
-
 /**
  * struct i2c_nmk_client - client specific data
  * @slave_adr: 7-bit slave address
- * @count: no. bytes to be transfered
+ * @count: no. bytes to be transferred
  * @buffer: client data buffer
- * @xfer_bytes: bytes transfered till now
+ * @xfer_bytes: bytes transferred till now
  * @operation: current I2C operation
  */
 struct i2c_nmk_client {
@@ -148,6 +146,7 @@ struct i2c_nmk_client {
  * @stop: stop condition
  * @xfer_complete: acknowledge completion for a I2C message
  * @result: controller propogated result
+ * @busy: Busy doing transfer
  */
 struct nmk_i2c_dev {
         struct platform_device          *pdev;
@@ -160,6 +159,8 @@ struct nmk_i2c_dev {
         int                             stop;
         struct completion               xfer_complete;
         int                             result;
+        struct regulator                *regulator;
+        bool                            busy;
 };
 
 /* controller's abort causes */
@@ -206,7 +207,7 @@ static int flush_i2c_fifo(struct nmk_i2c_dev *dev)
         writel((I2C_CR_FTX | I2C_CR_FRX), dev->virtbase + I2C_CR);
 
         for (i = 0; i < LOOP_ATTEMPTS; i++) {
-                timeout = jiffies + msecs_to_jiffies(I2C_TIMEOUT_MS);
+                timeout = jiffies + dev->adap.timeout;
 
                 while (!time_after(jiffies, timeout)) {
                         if ((readl(dev->virtbase + I2C_CR) &
@@ -252,7 +253,7 @@ static int init_hw(struct nmk_i2c_dev *dev)
 
         stat = flush_i2c_fifo(dev);
         if (stat)
-                return stat;
+                goto exit;
 
         /* disable the controller */
         i2c_clr_bit(dev->virtbase + I2C_CR , I2C_CR_PE);
@@ -263,7 +264,8 @@ static int init_hw(struct nmk_i2c_dev *dev)
 
         dev->cli.operation = I2C_NO_OPERATION;
 
-        return 0;
+exit:
+        return stat;
 }
 
 /* enable peripheral, master mode operation */
@@ -322,7 +324,7 @@ static void setup_i2c_controller(struct nmk_i2c_dev *dev)
          * slsu defines the data setup time after SCL clock
          * stretching in terms of i2c clk cycles. The
          * needed setup time for the three modes are 250ns,
-         * 100ns, 10ns repectively thus leading to the values
+         * 100ns, 10ns respectively thus leading to the values
          * of 14, 6, 2 for a 48 MHz i2c clk.
          */
         writel(dev->cfg.slsu << 16, dev->virtbase + I2C_SCR);
@@ -356,7 +358,7 @@ static void setup_i2c_controller(struct nmk_i2c_dev *dev)
         /*
          * set the speed mode. Currently we support
          * only standard and fast mode of operation
-         * TODO - support for fast mode plus (upto 1Mb/s)
+         * TODO - support for fast mode plus (up to 1Mb/s)
          * and high speed (up to 3.4 Mb/s)
          */
         if (dev->cfg.sm > I2C_FREQ_MODE_FAST) {
@@ -416,7 +418,7 @@ static int read_i2c(struct nmk_i2c_dev *dev)
                         dev->virtbase + I2C_IMSCR);
 
         timeout = wait_for_completion_interruptible_timeout(
-                &dev->xfer_complete, msecs_to_jiffies(I2C_TIMEOUT_MS));
+                &dev->xfer_complete, dev->adap.timeout);
 
         if (timeout < 0) {
                 dev_err(&dev->pdev->dev,
@@ -426,15 +428,32 @@ static int read_i2c(struct nmk_i2c_dev *dev)
         }
 
         if (timeout == 0) {
-                /* controler has timedout, re-init the h/w */
-                dev_err(&dev->pdev->dev, "controller timed out, re-init h/w\n");
-                (void) init_hw(dev);
+                /* Controller timed out */
+                dev_err(&dev->pdev->dev, "read from slave 0x%x timed out\n",
+                                dev->cli.slave_adr);
                 status = -ETIMEDOUT;
         }
-
         return status;
 }
 
+static void fill_tx_fifo(struct nmk_i2c_dev *dev, int no_bytes)
+{
+        int count;
+
+        for (count = (no_bytes - 2);
+                        (count > 0) &&
+                        (dev->cli.count != 0);
+                        count--) {
+                /* write to the Tx FIFO */
+                writeb(*dev->cli.buffer,
+                        dev->virtbase + I2C_TFR);
+                dev->cli.buffer++;
+                dev->cli.count--;
+                dev->cli.xfer_bytes++;
+        }
+
+}
+
 /**
  * write_i2c() - Write data to I2C client.
  * @dev: private data of I2C Driver
@@ -462,8 +481,13 @@ static int write_i2c(struct nmk_i2c_dev *dev)
         init_completion(&dev->xfer_complete);
 
         /* enable interrupts by settings the masks */
-        irq_mask = (I2C_IT_TXFNE | I2C_IT_TXFOVR |
-                        I2C_IT_MAL | I2C_IT_BERR);
+        irq_mask = (I2C_IT_TXFOVR | I2C_IT_MAL | I2C_IT_BERR);
+
+        /* Fill the TX FIFO with transmit data */
+        fill_tx_fifo(dev, MAX_I2C_FIFO_THRESHOLD);
+
+        if (dev->cli.count != 0)
+                irq_mask |= I2C_IT_TXFNE;
 
         /*
          * check if we want to transfer a single or multiple bytes, if so
@@ -481,7 +505,7 @@ static int write_i2c(struct nmk_i2c_dev *dev)
                         dev->virtbase + I2C_IMSCR);
 
         timeout = wait_for_completion_interruptible_timeout(
-                &dev->xfer_complete, msecs_to_jiffies(I2C_TIMEOUT_MS));
+                &dev->xfer_complete, dev->adap.timeout);
 
         if (timeout < 0) {
                 dev_err(&dev->pdev->dev,
@@ -491,9 +515,9 @@ static int write_i2c(struct nmk_i2c_dev *dev)
         }
 
         if (timeout == 0) {
-                /* controler has timedout, re-init the h/w */
-                dev_err(&dev->pdev->dev, "controller timed out, re-init h/w\n");
-                (void) init_hw(dev);
+                /* Controller timed out */
+                dev_err(&dev->pdev->dev, "write to slave 0x%x timed out\n",
+                                dev->cli.slave_adr);
                 status = -ETIMEDOUT;
         }
 
@@ -501,10 +525,55 @@ static int write_i2c(struct nmk_i2c_dev *dev)
 }
 
 /**
+ * nmk_i2c_xfer_one() - transmit a single I2C message
+ * @dev: device with a message encoded into it
+ * @flags: message flags
+ */
+static int nmk_i2c_xfer_one(struct nmk_i2c_dev *dev, u16 flags)
+{
+        int status;
+
+        if (flags & I2C_M_RD) {
+                /* read operation */
+                dev->cli.operation = I2C_READ;
+                status = read_i2c(dev);
+        } else {
+                /* write operation */
+                dev->cli.operation = I2C_WRITE;
+                status = write_i2c(dev);
+        }
+
+        if (status || (dev->result)) {
+                u32 i2c_sr;
+                u32 cause;
+
+                i2c_sr = readl(dev->virtbase + I2C_SR);
+                /*
+                 * Check if the controller I2C operation status
+                 * is set to ABORT(11b).
+                 */
+                if (((i2c_sr >> 2) & 0x3) == 0x3) {
+                        /* get the abort cause */
+                        cause = (i2c_sr >> 4) & 0x7;
+                        dev_err(&dev->pdev->dev, "%s\n", cause
+                                >= ARRAY_SIZE(abort_causes) ?
+                                "unknown reason" :
+                                abort_causes[cause]);
+                }
+
+                (void) init_hw(dev);
+
+                status = status ? status : dev->result;
+        }
+
+        return status;
+}
+
+/**
  * nmk_i2c_xfer() - I2C transfer function used by kernel framework
- * @i2c_adap    - Adapter pointer to the controller
- * @msgs[] - Pointer to data to be written.
- * @num_msgs - Number of messages to be executed
+ * @i2c_adap: Adapter pointer to the controller
+ * @msgs: Pointer to data to be written.
+ * @num_msgs: Number of messages to be executed
  *
  * This is the function called by the generic kernel i2c_transfer()
  * or i2c_smbus...() API calls. Note that this code is protected by the
@@ -552,49 +621,56 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap,
 {
         int status;
         int i;
-        u32 cause;
         struct nmk_i2c_dev *dev = i2c_get_adapdata(i2c_adap);
+        int j;
+
+        dev->busy = true;
+
+        if (dev->regulator)
+                regulator_enable(dev->regulator);
+        pm_runtime_get_sync(&dev->pdev->dev);
+
+        clk_enable(dev->clk);
 
         status = init_hw(dev);
         if (status)
-                return status;
+                goto out;
 
-        /* setup the i2c controller */
-        setup_i2c_controller(dev);
+        /* Attempt three times to send the message queue */
+        for (j = 0; j < 3; j++) {
+                /* setup the i2c controller */
+                setup_i2c_controller(dev);
 
-        for (i = 0; i < num_msgs; i++) {
-                if (unlikely(msgs[i].flags & I2C_M_TEN)) {
-                        dev_err(&dev->pdev->dev, "10 bit addressing"
-                                        "not supported\n");
-                        return -EINVAL;
-                }
-                dev->cli.slave_adr      = msgs[i].addr;
-                dev->cli.buffer         = msgs[i].buf;
-                dev->cli.count          = msgs[i].len;
-                dev->stop = (i < (num_msgs - 1)) ? 0 : 1;
-                dev->result = 0;
-
-                if (msgs[i].flags & I2C_M_RD) {
-                        /* it is a read operation */
-                        dev->cli.operation = I2C_READ;
-                        status = read_i2c(dev);
-                } else {
-                        /* write operation */
-                        dev->cli.operation = I2C_WRITE;
-                        status = write_i2c(dev);
-                }
-                if (status || (dev->result)) {
-                        /* get the abort cause */
-                        cause = (readl(dev->virtbase + I2C_SR) >> 4) & 0x7;
-                        dev_err(&dev->pdev->dev, "error during I2C"
-                                        "message xfer: %d\n", cause);
-                        dev_err(&dev->pdev->dev, "%s\n",
-                                cause >= ARRAY_SIZE(abort_causes)
-                                ? "unknown reason" : abort_causes[cause]);
-                        return status;
+                for (i = 0; i < num_msgs; i++) {
+                        if (unlikely(msgs[i].flags & I2C_M_TEN)) {
+                                dev_err(&dev->pdev->dev, "10 bit addressing"
+                                                "not supported\n");
+
+                                status = -EINVAL;
+                                goto out;
+                        }
+                        dev->cli.slave_adr      = msgs[i].addr;
+                        dev->cli.buffer         = msgs[i].buf;
+                        dev->cli.count          = msgs[i].len;
+                        dev->stop = (i < (num_msgs - 1)) ? 0 : 1;
+                        dev->result = 0;
+
+                        status = nmk_i2c_xfer_one(dev, msgs[i].flags);
+                        if (status != 0)
+                                break;
                 }
-                mdelay(1);
+                if (status == 0)
+                        break;
         }
+
+out:
+        clk_disable(dev->clk);
+        pm_runtime_put_sync(&dev->pdev->dev);
+        if (dev->regulator)
+                regulator_disable(dev->regulator);
+
+        dev->busy = false;
+
         /* return the no. messages processed */
         if (status)
                 return status;
@@ -605,6 +681,7 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap,
 /**
  * disable_interrupts() - disable the interrupts
  * @dev: private data of controller
+ * @irq: interrupt number
  */
 static int disable_interrupts(struct nmk_i2c_dev *dev, u32 irq)
 {
@@ -653,17 +730,7 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg)
                          */
                         disable_interrupts(dev, I2C_IT_TXFNE);
                 } else {
-                        for (count = (MAX_I2C_FIFO_THRESHOLD - tft - 2);
-                                        (count > 0) &&
-                                        (dev->cli.count != 0);
-                                        count--) {
-                                /* write to the Tx FIFO */
-                                writeb(*dev->cli.buffer,
-                                        dev->virtbase + I2C_TFR);
-                                dev->cli.buffer++;
-                                dev->cli.count--;
-                                dev->cli.xfer_bytes++;
-                        }
+                        fill_tx_fifo(dev, (MAX_I2C_FIFO_THRESHOLD - tft));
                         /*
                          * if done, close the transfer by disabling the
                          * corresponding TXFNE interrupt
@@ -716,16 +783,11 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg)
                         }
                 }
 
-                i2c_set_bit(dev->virtbase + I2C_ICR, I2C_IT_MTD);
-                i2c_set_bit(dev->virtbase + I2C_ICR, I2C_IT_MTDWS);
-
-                disable_interrupts(dev,
-                                (I2C_IT_TXFNE | I2C_IT_TXFE | I2C_IT_TXFF
-                                        | I2C_IT_TXFOVR | I2C_IT_RXFNF
-                                        | I2C_IT_RXFF | I2C_IT_RXFE));
+                disable_all_interrupts(dev);
+                clear_all_interrupts(dev);
 
                 if (dev->cli.count) {
-                        dev->result = -1;
+                        dev->result = -EIO;
                         dev_err(&dev->pdev->dev, "%lu bytes still remain to be"
                                         "xfered\n", dev->cli.count);
                         (void) init_hw(dev);
@@ -736,7 +798,7 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg)
 
         /* Master Arbitration lost interrupt */
         case I2C_IT_MAL:
-                dev->result = -1;
+                dev->result = -EIO;
                 (void) init_hw(dev);
 
                 i2c_set_bit(dev->virtbase + I2C_ICR, I2C_IT_MAL);
@@ -750,7 +812,7 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg)
          * during the transaction.
          */
         case I2C_IT_BERR:
-                dev->result = -1;
+                dev->result = -EIO;
                 /* get the status */
                 if (((readl(dev->virtbase + I2C_SR) >> 2) & 0x3) == I2C_ABORT)
                         (void) init_hw(dev);
@@ -766,7 +828,7 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg)
          * the Tx FIFO is full.
          */
         case I2C_IT_TXFOVR:
-                dev->result = -1;
+                dev->result = -EIO;
                 (void) init_hw(dev);
 
                 dev_err(&dev->pdev->dev, "Tx Fifo Over run\n");
@@ -792,12 +854,41 @@ static irqreturn_t i2c_irq_handler(int irq, void *arg)
         return IRQ_HANDLED;
 }
 
+
+#ifdef CONFIG_PM
+static int nmk_i2c_suspend(struct device *dev)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct nmk_i2c_dev *nmk_i2c = platform_get_drvdata(pdev);
+
+        if (nmk_i2c->busy)
+                return -EBUSY;
+
+        return 0;
+}
+
+static int nmk_i2c_resume(struct device *dev)
+{
+        return 0;
+}
+#else
+#define nmk_i2c_suspend NULL
+#define nmk_i2c_resume  NULL
+#endif
+
+/*
+ * We use noirq so that we suspend late and resume before the wakeup interrupt
+ * to ensure that we do the !pm_runtime_suspended() check in resume before
+ * there has been a regular pm runtime resume (via pm_runtime_get_sync()).
+ */
+static const struct dev_pm_ops nmk_i2c_pm = {
+        .suspend_noirq  = nmk_i2c_suspend,
+        .resume_noirq   = nmk_i2c_resume,
+};
+
 static unsigned int nmk_i2c_functionality(struct i2c_adapter *adap)
 {
-        return I2C_FUNC_I2C
-                | I2C_FUNC_SMBUS_BYTE_DATA
-                | I2C_FUNC_SMBUS_WORD_DATA
-                | I2C_FUNC_SMBUS_I2C_BLOCK;
+        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 }
 
 static const struct i2c_algorithm nmk_i2c_algo = {
@@ -820,7 +911,7 @@ static int __devinit nmk_i2c_probe(struct platform_device *pdev)
                 ret = -ENOMEM;
                 goto err_no_mem;
         }
-
+        dev->busy = false;
         dev->pdev = pdev;
         platform_set_drvdata(pdev, dev);
 
@@ -850,6 +941,15 @@ static int __devinit nmk_i2c_probe(struct platform_device *pdev)
                 goto err_irq;
         }
 
+        dev->regulator = regulator_get(&pdev->dev, "v-i2c");
+        if (IS_ERR(dev->regulator)) {
+                dev_warn(&pdev->dev, "could not get i2c regulator\n");
+                dev->regulator = NULL;
+        }
+
+        pm_suspend_ignore_children(&pdev->dev, true);
+        pm_runtime_enable(&pdev->dev);
+
         dev->clk = clk_get(&pdev->dev, NULL);
         if (IS_ERR(dev->clk)) {
                 dev_err(&pdev->dev, "could not get i2c clock\n");
@@ -857,13 +957,15 @@ static int __devinit nmk_i2c_probe(struct platform_device *pdev)
                 goto err_no_clk;
         }
 
-        clk_enable(dev->clk);
-
         adap = &dev->adap;
         adap->dev.parent = &pdev->dev;
         adap->owner     = THIS_MODULE;
         adap->class     = I2C_CLASS_HWMON | I2C_CLASS_SPD;
         adap->algo      = &nmk_i2c_algo;
+        adap->timeout   = pdata->timeout ? msecs_to_jiffies(pdata->timeout) :
+                msecs_to_jiffies(20000);
+        snprintf(adap->name, sizeof(adap->name),
+                 "Nomadik I2C%d at %lx", pdev->id, (unsigned long)res->start);
 
         /* fetch the controller id */
         adap->nr        = pdev->id;
@@ -877,14 +979,8 @@ static int __devinit nmk_i2c_probe(struct platform_device *pdev)
 
         i2c_set_adapdata(adap, dev);
 
-        ret = init_hw(dev);
-        if (ret != 0) {
-                dev_err(&pdev->dev, "error in initializing i2c hardware\n");
-                goto err_init_hw;
-        }
-
-        dev_dbg(&pdev->dev, "initialize I2C%d bus on virtual "
-                "base %p\n", pdev->id, dev->virtbase);
+        dev_info(&pdev->dev, "initialize %s on virtual "
+                "base %p\n", adap->name, dev->virtbase);
 
         ret = i2c_add_numbered_adapter(adap);
         if (ret) {
@@ -894,11 +990,12 @@ static int __devinit nmk_i2c_probe(struct platform_device *pdev)
 
         return 0;
 
- err_init_hw:
-        clk_disable(dev->clk);
  err_add_adap:
         clk_put(dev->clk);
  err_no_clk:
+        if (dev->regulator)
+                regulator_put(dev->regulator);
+        pm_runtime_disable(&pdev->dev);
         free_irq(dev->irq, dev);
  err_irq:
         iounmap(dev->virtbase);
@@ -928,8 +1025,10 @@ static int __devexit nmk_i2c_remove(struct platform_device *pdev)
         iounmap(dev->virtbase);
         if (res)
                 release_mem_region(res->start, resource_size(res));
-        clk_disable(dev->clk);
         clk_put(dev->clk);
+        if (dev->regulator)
+                regulator_put(dev->regulator);
+        pm_runtime_disable(&pdev->dev);
         platform_set_drvdata(pdev, NULL);
         kfree(dev);
 
@@ -940,6 +1039,7 @@ static struct platform_driver nmk_i2c_driver = {
         .driver = {
                 .owner = THIS_MODULE,
                 .name = DRIVER_NAME,
+                .pm = &nmk_i2c_pm,
         },
         .probe = nmk_i2c_probe,
         .remove = __devexit_p(nmk_i2c_remove),