I2C: OMAP: remove dev->idle, use usage counting provided by runtime PM

Current usage of runtime PM is not quite correct.  The actual
idle/unidle of the I2C hardware should not happen until the runtime PM
callbacks are called.  Therefore, change omap_i2c_[un]idle() functions
to only be called from the runtime PM callbacks (when usage count
transitions to/from zero.)

Also, the runtime PM core does usage counting and replaces
functionality currently managed by the dev->idle flag.  Remove usage
of dev->idle in favor of using runtime PM, and checking status using
pm_runtime_suspended().

Signed-off-by: Kevin Hilman <khilman@ti.com>

1 files changed, 39 insertions, 20 deletions

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index cddb29c15314..a43d0023446a 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -194,7 +194,6 @@ struct omap_i2c_dev {
                                                  */
         u8                      rev;
         unsigned                b_hw:1;         /* bad h/w fixes */
-        unsigned                idle:1;
         u16                     iestate;        /* Saved interrupt register */
         u16                     pscstate;
         u16                     scllstate;
@@ -269,12 +268,8 @@ static void omap_i2c_unidle(struct omap_i2c_dev *dev)
 {
         struct omap_i2c_bus_platform_data *pdata;
 
-        WARN_ON(!dev->idle);
-
         pdata = dev->dev->platform_data;
 
-        pm_runtime_get_sync(dev->dev);
-
         if (pdata->flags & OMAP_I2C_FLAG_RESET_REGS_POSTIDLE) {
                 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
                 omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, dev->pscstate);
@@ -285,7 +280,6 @@ static void omap_i2c_unidle(struct omap_i2c_dev *dev)
                 omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, dev->westate);
                 omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
         }
-        dev->idle = 0;
 
         /*
          * Don't write to this register if the IE state is 0 as it can
@@ -300,8 +294,6 @@ static void omap_i2c_idle(struct omap_i2c_dev *dev)
         struct omap_i2c_bus_platform_data *pdata;
         u16 iv;
 
-        WARN_ON(dev->idle);
-
         pdata = dev->dev->platform_data;
 
         dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
@@ -315,12 +307,9 @@ static void omap_i2c_idle(struct omap_i2c_dev *dev)
         } else {
                 omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, dev->iestate);
 
-                /* Flush posted write before the dev->idle store occurs */
+                /* Flush posted write */
                 omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
         }
-        dev->idle = 1;
-
-        pm_runtime_put_sync(dev->dev);
 }
 
 static int omap_i2c_init(struct omap_i2c_dev *dev)
@@ -644,7 +633,7 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
         int i;
         int r;
 
-        omap_i2c_unidle(dev);
+        pm_runtime_get_sync(dev->dev);
 
         r = omap_i2c_wait_for_bb(dev);
         if (r < 0)
@@ -667,7 +656,7 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 
         omap_i2c_wait_for_bb(dev);
 out:
-        omap_i2c_idle(dev);
+        pm_runtime_put(dev->dev);
         return r;
 }
 
@@ -727,7 +716,7 @@ omap_i2c_omap1_isr(int this_irq, void *dev_id)
         struct omap_i2c_dev *dev = dev_id;
         u16 iv, w;
 
-        if (dev->idle)
+        if (pm_runtime_suspended(dev->dev))
                 return IRQ_NONE;
 
         iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG);
@@ -819,7 +808,7 @@ omap_i2c_isr(int this_irq, void *dev_id)
 
         pdata = dev->dev->platform_data;
 
-        if (dev->idle)
+        if (pm_runtime_suspended(dev->dev))
                 return IRQ_NONE;
 
         bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
@@ -1021,7 +1010,6 @@ omap_i2c_probe(struct platform_device *pdev)
         }
 
         dev->speed = speed;
-        dev->idle = 1;
         dev->dev = &pdev->dev;
         dev->irq = irq->start;
         dev->base = ioremap(mem->start, resource_size(mem));
@@ -1040,7 +1028,7 @@ omap_i2c_probe(struct platform_device *pdev)
                 dev->regs = (u8 *)reg_map_ip_v1;
 
         pm_runtime_enable(dev->dev);
-        omap_i2c_unidle(dev);
+        pm_runtime_get_sync(dev->dev);
 
         dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;
 
@@ -1087,7 +1075,7 @@ omap_i2c_probe(struct platform_device *pdev)
         dev_info(dev->dev, "bus %d rev%d.%d.%d at %d kHz\n", pdev->id,
                  pdata->rev, dev->rev >> 4, dev->rev & 0xf, dev->speed);
 
-        omap_i2c_idle(dev);
+        pm_runtime_put(dev->dev);
 
         adap = &dev->adapter;
         i2c_set_adapdata(adap, dev);
@@ -1111,7 +1099,7 @@ err_free_irq:
         free_irq(dev->irq, dev);
 err_unuse_clocks:
         omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
-        omap_i2c_idle(dev);
+        pm_runtime_put(dev->dev);
         iounmap(dev->base);
 err_free_mem:
         platform_set_drvdata(pdev, NULL);
@@ -1140,12 +1128,43 @@ omap_i2c_remove(struct platform_device *pdev)
         return 0;
 }
 
+#ifdef CONFIG_PM_RUNTIME
+static int omap_i2c_runtime_suspend(struct device *dev)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
+
+        omap_i2c_idle(_dev);
+
+        return 0;
+}
+
+static int omap_i2c_runtime_resume(struct device *dev)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
+
+        omap_i2c_unidle(_dev);
+
+        return 0;
+}
+
+static struct dev_pm_ops omap_i2c_pm_ops = {
+        .runtime_suspend = omap_i2c_runtime_suspend,
+        .runtime_resume = omap_i2c_runtime_resume,
+};
+#define OMAP_I2C_PM_OPS (&omap_i2c_pm_ops)
+#else
+#define OMAP_I2C_PM_OPS NULL
+#endif
+
 static struct platform_driver omap_i2c_driver = {
         .probe          = omap_i2c_probe,
         .remove         = omap_i2c_remove,
         .driver         = {
                 .name   = "omap_i2c",
                 .owner  = THIS_MODULE,
+                .pm     = OMAP_I2C_PM_OPS,
         },
 };