linux-kernel - Re: [PATCH 2/2] Input: pm8941-pwrkey: Introduce reboot mode support

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Date:   Mon, 29 May 2017 19:53:24 -0700
From:   Dmitry Torokhov <dmitry.torokhov@...il.com>
To:     Bjorn Andersson <bjorn.andersson@...aro.org>
Cc:     Rob Herring <robh@...nel.org>,
        John Stultz <john.stultz@...aro.org>,
        linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-arm-msm@...r.kernel.org, Sebastian Reichel <sre@...nel.org>,
        linux-pm@...r.kernel.org
Subject: Re: [PATCH 2/2] Input: pm8941-pwrkey: Introduce reboot mode support

On Fri, May 26, 2017 at 11:51:30PM -0700, Bjorn Andersson wrote:
> In some Qualcomm platforms the magic for informing LK which mode to
> reboot into is stored in the PON_SOFT_RB_SPARE register. Register with
> the reboot mode helpers to expose this to the user.

Hmm, is the power key driver the best place to have this? WHy isn't this
a driver in its own right?

> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@...aro.org>
> ---
>  drivers/input/misc/Kconfig         |  1 +
>  drivers/input/misc/pm8941-pwrkey.c | 28 ++++++++++++++++++++++++++++
>  2 files changed, 29 insertions(+)
> 
> diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
> index 3872488c3fd7..56552e16fab1 100644
> --- a/drivers/input/misc/Kconfig
> +++ b/drivers/input/misc/Kconfig
> @@ -132,6 +132,7 @@ config INPUT_PCSPKR
>  config INPUT_PM8941_PWRKEY
>  	tristate "Qualcomm PM8941 power key support"
>  	depends on MFD_SPMI_PMIC
> +	select REBOOT_MODE
>  	help
>  	  Say Y here if you want support for the power key usually found
>  	  on boards using a Qualcomm PM8941 compatible PMIC.
> diff --git a/drivers/input/misc/pm8941-pwrkey.c b/drivers/input/misc/pm8941-pwrkey.c
> index 18ad956454f1..c48be6dbaa78 100644
> --- a/drivers/input/misc/pm8941-pwrkey.c
> +++ b/drivers/input/misc/pm8941-pwrkey.c
> @@ -22,6 +22,7 @@
>  #include <linux/of.h>
>  #include <linux/platform_device.h>
>  #include <linux/reboot.h>
> +#include <linux/reboot-mode.h>
>  #include <linux/regmap.h>
>  
>  #define PON_REV2			0x01
> @@ -42,6 +43,7 @@
>  #define PON_DBC_CTL			0x71
>  #define  PON_DBC_DELAY_MASK		0x7
>  
> +#define PON_SOFT_RB_SPARE		0x8f
>  
>  struct pm8941_pwrkey {
>  	struct device *dev;
> @@ -52,8 +54,26 @@ struct pm8941_pwrkey {
>  
>  	unsigned int revision;
>  	struct notifier_block reboot_notifier;
> +
> +	struct reboot_mode_driver reboot_mode;
>  };
>  
> +static int pm8941_reboot_mode_write(struct reboot_mode_driver *reboot,
> +				    unsigned int magic)
> +{
> +	struct pm8941_pwrkey *pwrkey = container_of(reboot, struct pm8941_pwrkey,
> +						    reboot_mode);
> +	int ret;
> +
> +	ret = regmap_update_bits(pwrkey->regmap,
> +				 pwrkey->baseaddr + PON_SOFT_RB_SPARE,
> +				 0xfc, magic << 2);
> +	if (ret < 0)
> +		dev_err(pwrkey->dev, "update reboot mode bits failed\n");
> +
> +	return ret;
> +}
> +
>  static int pm8941_reboot_notify(struct notifier_block *nb,
>  				unsigned long code, void *unused)
>  {
> @@ -256,6 +276,14 @@ static int pm8941_pwrkey_probe(struct platform_device *pdev)
>  		return error;
>  	}
>  
> +	pwrkey->reboot_mode.dev = &pdev->dev;
> +	pwrkey->reboot_mode.write = pm8941_reboot_mode_write;
> +	error = devm_reboot_mode_register(&pdev->dev, &pwrkey->reboot_mode);
> +	if (error) {
> +		dev_err(&pdev->dev, "can't register reboot mode\n");
> +		return error;
> +	}
> +
>  	platform_set_drvdata(pdev, pwrkey);
>  	device_init_wakeup(&pdev->dev, 1);
>  
> -- 
> 2.12.0
> 

Thanks.

-- 
Dmitry