[PATCH 0/3] I2C: OMAP: PM related cleanup

[PATCH 0/3] I2C: OMAP: PM related cleanup

[Kevin Hilman]

Here's a small series of PM-related cleanups for the OMAP I2C driver.

Series applies on top of the other cleanup series from Andy Green:

  [PATCH v4 00/18] I2C: OMAP: I2C fixes, removal of cpu_is... from driver

and is available from git here:

  git://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-omap-pm.git wip/i2c

Kevin Hilman (3):
  I2C: OMAP: remove unneccesary use of pdev
  I2C: OMAP: remove dev->idle, use usage counting provided by runtime
    PM
  I2C: OMAP: remove racy suspend/resume callbacks

 drivers/i2c/busses/i2c-omap.c |   70 +++++++++++++++-------------------------
 1 files changed, 26 insertions(+), 44 deletions(-)

-- 
1.7.4

[PATCH 1/3] I2C: OMAP: remove unneccesary use of pdev

[Kevin Hilman]

A pointer to the struct device associated with the i2c device is
already kept in the struct omap_i2c_dev, so use omap_i2c_device to
find the pointer to struct device.

Signed-off-by: Kevin Hilman <khilman@ti.com>
---
 drivers/i2c/busses/i2c-omap.c |   22 +++++++---------------
 1 files changed, 7 insertions(+), 15 deletions(-)

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index d53cd61..8633488 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -267,15 +267,13 @@ static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
 
 static void omap_i2c_unidle(struct omap_i2c_dev *dev)
 {
-	struct platform_device *pdev;
 	struct omap_i2c_bus_platform_data *pdata;
 
 	WARN_ON(!dev->idle);
 
-	pdev = to_platform_device(dev->dev);
-	pdata = pdev->dev.platform_data;
+	pdata = dev->dev->platform_data;
 
-	pm_runtime_get_sync(&pdev->dev);
+	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);
@@ -299,14 +297,12 @@ static void omap_i2c_unidle(struct omap_i2c_dev *dev)
 
 static void omap_i2c_idle(struct omap_i2c_dev *dev)
 {
-	struct platform_device *pdev;
 	struct omap_i2c_bus_platform_data *pdata;
 	u16 iv;
 
 	WARN_ON(dev->idle);
 
-	pdev = to_platform_device(dev->dev);
-	pdata = pdev->dev.platform_data;
+	pdata = dev->dev->platform_data;
 
 	dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
 	if (pdata->rev == OMAP_I2C_IP_VERSION_2)
@@ -324,7 +320,7 @@ static void omap_i2c_idle(struct omap_i2c_dev *dev)
 	}
 	dev->idle = 1;
 
-	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_put_sync(dev->dev);
 }
 
 static int omap_i2c_init(struct omap_i2c_dev *dev)
@@ -335,11 +331,9 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
 	unsigned long timeout;
 	unsigned long internal_clk = 0;
 	struct clk *fclk;
-	struct platform_device *pdev;
 	struct omap_i2c_bus_platform_data *pdata;
 
-	pdev = to_platform_device(dev->dev);
-	pdata = pdev->dev.platform_data;
+	pdata = dev->dev->platform_data;
 
 	if (dev->rev >= OMAP_I2C_OMAP1_REV_2) {
 		/* Disable I2C controller before soft reset */
@@ -822,11 +816,9 @@ omap_i2c_isr(int this_irq, void *dev_id)
 	u16 bits;
 	u16 stat, w;
 	int err, count = 0;
-	struct platform_device *pdev;
 	struct omap_i2c_bus_platform_data *pdata;
 
-	pdev = to_platform_device(dev->dev);
-	pdata = pdev->dev.platform_data;
+	pdata = dev->dev->platform_data;
 
 	if (dev->idle)
 		return IRQ_NONE;
@@ -1048,7 +1040,7 @@ omap_i2c_probe(struct platform_device *pdev)
 	else
 		dev->regs = (u8 *)reg_map_ip_v1;
 
-	pm_runtime_enable(&pdev->dev);
+	pm_runtime_enable(dev->dev);
 	omap_i2c_unidle(dev);
 
 	dev->rev = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) & 0xff;
-- 
1.7.4

[PATCH 2/3] I2C: OMAP: remove dev->idle, use usage counting provided by runtime PM

[Kevin Hilman]

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>
---
 drivers/i2c/busses/i2c-omap.c |   52 ++++++++++++++++++++++++----------------
 1 files changed, 31 insertions(+), 21 deletions(-)

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 8633488..4e3256f 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)
@@ -645,7 +634,7 @@ 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)
@@ -668,7 +657,7 @@ 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_sync(dev->dev);
 	return r;
 }
 
@@ -728,7 +717,7 @@ 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);
@@ -820,7 +809,7 @@ 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);
@@ -1022,7 +1011,6 @@ 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));
@@ -1041,7 +1029,7 @@ 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;
 
@@ -1088,7 +1076,7 @@ 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_sync(dev->dev);
 
 	adap = &dev->adapter;
 	i2c_set_adapdata(adap, dev);
@@ -1112,7 +1100,7 @@ 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_sync(dev->dev);
 	iounmap(dev->base);
 err_free_mem:
 	platform_set_drvdata(pdev, NULL);
@@ -1141,7 +1129,27 @@ omap_i2c_remove(struct platform_device *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_SUSPEND
+#ifdef CONFIG_PM
+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 int omap_i2c_suspend(struct device *dev)
 {
 	if (!pm_runtime_suspended(dev))
@@ -1163,6 +1171,8 @@ static int omap_i2c_resume(struct device *dev)
 static struct dev_pm_ops omap_i2c_pm_ops = {
 	.suspend = omap_i2c_suspend,
 	.resume = omap_i2c_resume,
+	.runtime_suspend = omap_i2c_runtime_suspend,
+	.runtime_resume = omap_i2c_runtime_resume,
 };
 #define OMAP_I2C_PM_OPS (&omap_i2c_pm_ops)
 #else
-- 
1.7.4

[PATCH 3/3] I2C: OMAP: remove racy suspend/resume callbacks

[Kevin Hilman]

Current system PM methods for this driver race with the runtime PM
methods when an i2c xfer is in progress when the system suspend path
is excuted.

These callbacks are only needed when runtime PM is disabled from
userspace, so for now we accept that this device will not hit
retention, even in suspend, if runtime PM disabled.

The correct fix (forthcoming) for v3.0+ is to use device power domain
callbacks at the system PM level to handle this, but for now, this
avoids the race.

Signed-off-by: Kevin Hilman <khilman@ti.com>
---
 drivers/i2c/busses/i2c-omap.c |   20 --------------------
 1 files changed, 0 insertions(+), 20 deletions(-)

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 4e3256f..77ed95f 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -1150,27 +1150,7 @@ static int omap_i2c_runtime_resume(struct device *dev)
 	return 0;
 }
 
-static int omap_i2c_suspend(struct device *dev)
-{
-	if (!pm_runtime_suspended(dev))
-		if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend)
-			dev->bus->pm->runtime_suspend(dev);
-
-	return 0;
-}
-
-static int omap_i2c_resume(struct device *dev)
-{
-	if (!pm_runtime_suspended(dev))
-		if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume)
-			dev->bus->pm->runtime_resume(dev);
-
-	return 0;
-}
-
 static struct dev_pm_ops omap_i2c_pm_ops = {
-	.suspend = omap_i2c_suspend,
-	.resume = omap_i2c_resume,
 	.runtime_suspend = omap_i2c_runtime_suspend,
 	.runtime_resume = omap_i2c_runtime_resume,
 };
-- 
1.7.4