On 01/21/2012 02:28 PM, Mark Brown wrote:
> Add stub runtime_pm calls which go through the flow of enabling and
> disabling but don't actually do anything with the device itself as
> there's nothing useful we can do. This provides the core PM framework
> with information about when the device is idle, enabling chip wide
> power savings.
>
> Signed-off-by: Mark Brown<broonie-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@xxxxxxxxxxxxxxxx>
> Acked-by: Heiko Stuebner<heiko-4mtYJXux2i+zQB+pC5nmwQ@xxxxxxxxxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-s3c2410.c | 10 ++++++++++
> 1 files changed, 10 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
> index e6f982b..737f721 100644
> --- a/drivers/i2c/busses/i2c-s3c2410.c
> +++ b/drivers/i2c/busses/i2c-s3c2410.c
> @@ -31,6 +31,7 @@
> #include<linux/errno.h>
> #include<linux/err.h>
> #include<linux/platform_device.h>
> +#include<linux/pm_runtime.h>
> #include<linux/clk.h>
> #include<linux/cpufreq.h>
> #include<linux/slab.h>
> @@ -564,6 +565,7 @@ static int s3c24xx_i2c_xfer(struct i2c_adapter *adap,
> int retry;
> int ret;
>
> + pm_runtime_get_sync(&adap->dev);
> clk_enable(i2c->clk);
It looks a bit strange to have pm_runtime* and manual clock control side
by side. How about implementing proper runtime_suspend/resume calls and
moving clk_enable/disable to these handlers ?
It might also make sense to check return value of pm_runtime_get_sync().
> for (retry = 0; retry< adap->retries; retry++) {
> @@ -572,6 +574,7 @@ static int s3c24xx_i2c_xfer(struct i2c_adapter *adap,
>
> if (ret != -EAGAIN) {
> clk_disable(i2c->clk);
> + pm_runtime_put_sync(&adap->dev);
I would go for just pm_runtime_put() here...
> return ret;
> }
>
> @@ -581,6 +584,7 @@ static int s3c24xx_i2c_xfer(struct i2c_adapter *adap,
> }
>
> clk_disable(i2c->clk);
> + pm_runtime_put_sync(&adap->dev);
.. and here as well.
> return -EREMOTEIO;
> }
>
> @@ -1013,6 +1017,9 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
> of_i2c_register_devices(&i2c->adap);
> platform_set_drvdata(pdev, i2c);
>
> + pm_runtime_enable(&pdev->dev);
> + pm_runtime_enable(&i2c->adap.dev);
Why do we need pm_runtime_enable() on i2c->adap.dev ?
AFAIK enabling runtime PM on the platform device only should do.
> +
> dev_info(&pdev->dev, "%s: S3C I2C adapter\n", dev_name(&i2c->adap.dev));
> clk_disable(i2c->clk);
> return 0;
> @@ -1047,6 +1054,9 @@ static int s3c24xx_i2c_remove(struct platform_device *pdev)
> {
> struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);
>
> + pm_runtime_disable(&i2c->adap.dev);
> + pm_runtime_disable(&pdev->dev);
Ditto.
> +
> s3c24xx_i2c_deregister_cpufreq(i2c);
>
> i2c_del_adapter(&i2c->adap);
--
Thanks,
Sylwester
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