[PATCH v3 12/47] mfd: ab8500-sysctrl: Register with kernel power-off handler

Lee Jones
2014-11-03T17:55:46Z

On Mon, 27 Oct 2014, Guenter Roeck wrote:

> Register with kernel power-off handler instead of setting pm_power_off
> directly. Register with low priority to reflect that the original code
> only sets pm_power_off if it was not already set.
>
> sysctrl_dev is set prior to power-off handler registration, and the
> power-off handler is unregistered prior to clearing sysrctrl_dev.
> It is therefore not necessary to check if sysctrl_dev is NULL in the
> power-off handler, and the check was removed. Setting sysctrl_dev to NULL
> in the remove function was also removed as unnecessary. With those changes,
> devm_register_power_off_handler can be used to register the poeroff handler.
> The now empty remove function was retained since the ab8500_restart function,
> which is currently unused, would likely need some cleanup if it was ever used.
>
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Cc: Lee Jones <lee.jones@linaro.org>
> Cc: Samuel Ortiz <sameo@linux.intel.com>
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---
> v3:
> - Replace poweroff in all newly introduced variables and in text
> with power_off or power-off as appropriate
> - Replace POWEROFF_PRIORITY_xxx with POWER_OFF_PRIORITY_xxx
> v2:
> - Use define to specify poweroff handler priority
> - Use devm_register_power_off_handler
> - Use dev_warn instead of dev_err
> - Since we use devm_register_power_off_handler,
> we need to check if sysctrl_dev in the poweroff handler to avoid
> a race condition on unload, so this check is no longer removed
>
> drivers/mfd/ab8500-sysctrl.c | 23 ++++++++++++++++-------
> 1 file changed, 16 insertions(+), 7 deletions(-)

Acked-by: Lee Jones <lee.jones@linaro.org>

> diff --git a/drivers/mfd/ab8500-sysctrl.c b/drivers/mfd/ab8500-sysctrl.c
> index 8e0dae5..c49ecaf 100644
> --- a/drivers/mfd/ab8500-sysctrl.c
> +++ b/drivers/mfd/ab8500-sysctrl.c
> @@ -6,6 +6,7 @@
>
> #include <linux/err.h>
> #include <linux/module.h>
> +#include <linux/notifier.h>
> #include <linux/platform_device.h>
> #include <linux/pm.h>
> #include <linux/reboot.h>
> @@ -23,7 +24,8 @@
>
> static struct device *sysctrl_dev;
>
> -static void ab8500_power_off(void)
> +static int ab8500_power_off(struct notifier_block *this, unsigned long unused1,
> + void *unused2)
> {
> sigset_t old;
> sigset_t all;
> @@ -36,7 +38,7 @@ static void ab8500_power_off(void)
>
> if (sysctrl_dev == NULL) {
> pr_err("%s: sysctrl not initialized\n", __func__);
> - return;
> + return NOTIFY_DONE;
> }
>
> /*
> @@ -83,8 +85,15 @@ shutdown:
> AB8500_STW4500CTRL1_SWRESET4500N);
> (void)sigprocmask(SIG_SETMASK, &old, NULL);
> }
> +
> + return NOTIFY_DONE;
> }
>
> +static struct notifier_block ab8500_power_off_nb = {
> + .notifier_call = ab8500_power_off,
> + .priority = POWER_OFF_PRIORITY_LOW,
> +};
> +
> /*
> * Use the AB WD to reset the platform. It will perform a hard
> * reset instead of a soft reset. Write the reset reason to
> @@ -185,6 +194,7 @@ static int ab8500_sysctrl_probe(struct platform_device *pdev)
> struct ab8500 *ab8500 = dev_get_drvdata(pdev->dev.parent);
> struct ab8500_platform_data *plat;
> struct ab8500_sysctrl_platform_data *pdata;
> + int err;
>
> plat = dev_get_platdata(pdev->dev.parent);
>
> @@ -193,8 +203,10 @@ static int ab8500_sysctrl_probe(struct platform_device *pdev)
>
> sysctrl_dev = &pdev->dev;
>
> - if (!pm_power_off)
> - pm_power_off = ab8500_power_off;
> + err = devm_register_power_off_handler(sysctrl_dev,
> + &ab8500_power_off_nb);
> + if (err)
> + dev_warn(&pdev->dev, "Failed to register power-off handler\n");
>
> pdata = plat->sysctrl;
> if (pdata) {
> @@ -228,9 +240,6 @@ static int ab8500_sysctrl_remove(struct platform_device *pdev)
> {
> sysctrl_dev = NULL;
>
> - if (pm_power_off == ab8500_power_off)
> - pm_power_off = NULL;
> -
> return 0;
> }
>

--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org ? Open source software for ARM SoCs
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