[PATCH] imx_keypad: add PM support

[Dmitry Torokhov]

Hi Eric,

On Sun, May 30, 2010 at 10:51:06AM +0200, Eric Bénard wrote:
> * add suspend/resume support
> * use keypad_data to enable wakeup from platform data
> * suspend/resume tested when keypad is not in use and when it's
> is use (in which case we immediatly get the key pressed for
> wakeup)
> 
> Signed-off-by: Eric Bénard <eric at eukrea.com>
> ---
>  drivers/input/keyboard/imx_keypad.c |   56 +++++++++++++++++++++++++++++++++-
>  1 files changed, 54 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/input/keyboard/imx_keypad.c b/drivers/input/keyboard/imx_keypad.c
> index d92c15c..b303cc9 100644
> --- a/drivers/input/keyboard/imx_keypad.c
> +++ b/drivers/input/keyboard/imx_keypad.c
> @@ -364,6 +364,55 @@ static void imx_keypad_inhibit(struct imx_keypad *keypad)
>  	writew(0xff00, keypad->mmio_base + KPCR);
>  }
>  
> +static int mxc_kpp_suspend(struct platform_device *pdev, pm_message_t state)
> +{
> +	struct imx_keypad *keypad = platform_get_drvdata(pdev);
> +	unsigned short reg_val;
> +
> +	clk_disable(keypad->clk);
> +
> +	if (device_may_wakeup(&pdev->dev)) {
> +		reg_val = readw(keypad->mmio_base + KPSR);
> +		if ((reg_val & KBD_STAT_KDIE) == 0) {
> +			/* If no depress interrupt enable the release interrupt */
> +			reg_val |= KBD_STAT_KRIE;
> +			writew(reg_val, keypad->mmio_base + KPSR);
> +		}
> +		enable_irq_wake(keypad->irq);
> +	} else {
> +		keypad->enabled = false;
> +		synchronize_irq(keypad->irq);
> +		disable_irq(keypad->irq);

I'd factor it out as it is used in both suspend and close.

Does everythig (clk_disable, eit) work well in case when device is still
closed when it get ssuspended?

Also, do you really need such an elaborate setup when device is/is not
wakeup source? Do you really loose keypress if you always dosable IRQ in
suspend and enable it in resume?

> +	}
> +
> +	return 0;
> +}
> +
> +/*!
> + * This function brings the Keypad controller back from low-power state.
> + * If Keypad is enabled as a wake source(i.e. it can resume the system
> + * from suspend mode), the Keypad controller doesn't enter low-power state.
> + *
> + * @param   pdev  the device structure used to give information on Keypad
> + *                to resume
> + *
> + * @return  The function always returns 0.
> + */

This is not the standard kerneldoc markup.

> +static int mxc_kpp_resume(struct platform_device *pdev)
> +{
> +	struct imx_keypad *keypad = platform_get_drvdata(pdev);
> +
> +	clk_enable(keypad->clk);
> +	if (device_may_wakeup(&pdev->dev)) {
> +		/* The irq routine already cleared KRIE if it was set */
> +	} else {
> +		keypad->enabled = true;
> +		enable_irq(keypad->irq);
> +	}
> +
> +	return 0;
> +}
> +
>  static void imx_keypad_close(struct input_dev *dev)
>  {
>  	struct imx_keypad *keypad = input_get_drvdata(dev);
> @@ -410,7 +459,8 @@ open_err:
>  
>  static int __devinit imx_keypad_probe(struct platform_device *pdev)
>  {
> -	const struct matrix_keymap_data *keymap_data = pdev->dev.platform_data;
> +	const struct matrix_keypad_platform_data *keypad_data = pdev->dev.platform_data;
> +	const struct matrix_keymap_data *keymap_data = keypad_data->keymap_data;
>  	struct imx_keypad *keypad;
>  	struct input_dev *input_dev;
>  	struct resource *res;
> @@ -525,7 +575,7 @@ static int __devinit imx_keypad_probe(struct platform_device *pdev)
>  	}
>  
>  	platform_set_drvdata(pdev, keypad);
> -	device_init_wakeup(&pdev->dev, 1);
> +	device_init_wakeup(&pdev->dev, keypad_data->wakeup);
>  
>  	return 0;
>  
> @@ -574,6 +624,8 @@ static struct platform_driver imx_keypad_driver = {
>  	},
>  	.probe		= imx_keypad_probe,
>  	.remove		= __devexit_p(imx_keypad_remove),
> +	.suspend = mxc_kpp_suspend,
> +	.resume = mxc_kpp_resume,

Please use pm_ops.

Thanks.

-- 
Dmitry