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

Kevin Hilman
2011-08-03T18:08:52Z

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 | 58 ++++++++++++++++++++++++++--------------
1 files changed, 38 insertions(+), 20 deletions(-)

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 12d0cbc..1b5325b 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_sync(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_sync(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_sync(dev->dev);
iounmap(dev->base);
err_free_mem:
platform_set_drvdata(pdev, NULL);
@@ -1140,6 +1128,36 @@ 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,
--
1.7.6