On Thu, 07 Oct 2021, Dmitry Osipenko wrote:
> Use new power off call chain API which allows multiple power off handlers
> to coexist. Nexus 7 Android tablet can be powered off using MAX77663 PMIC
> and using a special bootloader command. At first the bootloader option
> should be tried, it will have a higher priority than the PMIC.
>
> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
> ---
> drivers/mfd/max77620.c | 22 +++++++++++++++-------
> include/linux/mfd/max77620.h | 2 ++
> 2 files changed, 17 insertions(+), 7 deletions(-)
I don't have a problem with the approach in general.
I guess it's up to the relevant maintainers to decide.
> diff --git a/drivers/mfd/max77620.c b/drivers/mfd/max77620.c
> index fec2096474ad..ad40eed1f0c6 100644
> --- a/drivers/mfd/max77620.c
> +++ b/drivers/mfd/max77620.c
> @@ -31,11 +31,10 @@
> #include <linux/init.h>
> #include <linux/of.h>
> #include <linux/of_device.h>
> +#include <linux/reboot.h>
> #include <linux/regmap.h>
> #include <linux/slab.h>
>
> -static struct max77620_chip *max77620_scratch;
> -
> static const struct resource gpio_resources[] = {
> DEFINE_RES_IRQ(MAX77620_IRQ_TOP_GPIO),
> };
> @@ -483,13 +482,17 @@ static int max77620_read_es_version(struct max77620_chip *chip)
> return ret;
> }
>
> -static void max77620_pm_power_off(void)
> +static int max77620_pm_power_off(struct notifier_block *nb,
> + unsigned long reboot_mode, void *data)
> {
> - struct max77620_chip *chip = max77620_scratch;
> + struct max77620_chip *chip = container_of(nb, struct max77620_chip,
> + pm_off_nb);
>
> regmap_update_bits(chip->rmap, MAX77620_REG_ONOFFCNFG1,
> MAX77620_ONOFFCNFG1_SFT_RST,
> MAX77620_ONOFFCNFG1_SFT_RST);
> +
> + return NOTIFY_DONE;
> }
>
> static int max77620_probe(struct i2c_client *client,
> @@ -566,9 +569,14 @@ static int max77620_probe(struct i2c_client *client,
> }
>
> pm_off = of_device_is_system_power_controller(client->dev.of_node);
> - if (pm_off && !pm_power_off) {
> - max77620_scratch = chip;
> - pm_power_off = max77620_pm_power_off;
> + if (pm_off) {
> + chip->pm_off_nb.notifier_call = max77620_pm_power_off;
> + chip->pm_off_nb.priority = 128;
> +
> + ret = devm_register_poweroff_handler(chip->dev, &chip->pm_off_nb);
> + if (ret < 0)
> + dev_err(chip->dev,
> + "Failed to register poweroff handler: %d\n", ret);
> }
>
> return 0;
> diff --git a/include/linux/mfd/max77620.h b/include/linux/mfd/max77620.h
> index f552ef5b1100..99de4f8c9cbf 100644
> --- a/include/linux/mfd/max77620.h
> +++ b/include/linux/mfd/max77620.h
> @@ -8,6 +8,7 @@
> #ifndef _MFD_MAX77620_H_
> #define _MFD_MAX77620_H_
>
> +#include <linux/notifier.h>
> #include <linux/types.h>
>
> /* GLOBAL, PMIC, GPIO, FPS, ONOFFC, CID Registers */
> @@ -327,6 +328,7 @@ enum max77620_chip_id {
> struct max77620_chip {
> struct device *dev;
> struct regmap *rmap;
> + struct notifier_block pm_off_nb;
>
> int chip_irq;
>
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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