Re: [PATCH v2 3/4] i2c: davinci: Add suspend/resume support

[Kevin Hilman <khilman-1D3HCaltpLuhEniVeURVKkEOCMrvLtNR@public.gmane.org>]

Chaithrika U S <chaithrika-l0cyMroinI0@public.gmane.org> writes:

> Add suspend and resume callbacks to DaVinci I2C driver.
> This has been tested on DA850/OMAP-L138 EVM. The SoC specific
> suspend-to-RAM support patch series [1] is needed to test this feature.
>
> [1] http://linux.davincidsp.com/pipermail/davinci-linux-open-source/
> 2009-November/016958.html
>
> Signed-off-by: Chaithrika U S <chaithrika-l0cyMroinI0@public.gmane.org>
> ---
>  drivers/i2c/busses/i2c-davinci.c |   32 ++++++++++++++++++++++++++++++++
>  1 files changed, 32 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
> index 81c1049..c1c2909 100644
> --- a/drivers/i2c/busses/i2c-davinci.c
> +++ b/drivers/i2c/busses/i2c-davinci.c
> @@ -622,6 +622,36 @@ static int davinci_i2c_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> +#ifdef CONFIG_PM
> +static int davinci_i2c_suspend(struct platform_device *pdev, pm_message_t state)
> +{
> +	struct davinci_i2c_dev *dev = platform_get_drvdata(pdev);
> +
> +	/* put I2C into reset */
> +	davinci_i2c_reset_ctrl(dev, 0);
> +
> +	clk_disable(dev->clk);
> +
> +	return 0;
> +}
> +
> +static int davinci_i2c_resume(struct platform_device *pdev)
> +{
> +	struct davinci_i2c_dev *dev = platform_get_drvdata(pdev);
> +
> +	clk_enable(dev->clk);
> +
> +	/* take I2C out of reset */
> +	davinci_i2c_reset_ctrl(dev, 1);
> +
> +	return 0;
> +}
> +
> +#else
> +#define davinci_i2c_suspend NULL
> +#define davinci_i2c_resume NULL
> +#endif
> +
>  /* work with hotplug and coldplug */
>  MODULE_ALIAS("platform:i2c_davinci");
>  
> @@ -632,6 +662,8 @@ static struct platform_driver davinci_i2c_driver = {
>  		.name	= "i2c_davinci",
>  		.owner	= THIS_MODULE,
>  	},
> +	.suspend	= davinci_i2c_suspend,
> +	.resume		= davinci_i2c_resume,

Rather than adding these to the platform_driver, you should use dev_pm_ops.

Something like the patch below on top of your PATCH 3/4 should work.

Other than this, I'm OK with this series, feel free to add my signoff
and resend to linux-i2c and LKML.  linux-i2c has had very slow
response to embedded patches lately.

Kevin