Re: [PATCH v7 5/7] power: reset: add driver for mt6323 poweroff

[Sean Wang]

Hi, Frank

On Tue, 2019-09-10 at 09:04 +0200, Frank Wunderlich wrote:
> From: Josef Friedl <josef.friedl@xxxxxxxx>
> 
> add poweroff driver for mt6323 and make Makefile and Kconfig-Entries
> 
> Suggested-by: Frank Wunderlich <frank-w@xxxxxxxxxxxxxxx>
> Signed-off-by: Josef Friedl <josef.friedl@xxxxxxxx>
> Signed-off-by: Frank Wunderlich <frank-w@xxxxxxxxxxxxxxx>
> Acked-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>


Thanks for your help keep the unfinished driver to upstream

Acked-by: Sean Wang <sean.wang@xxxxxxxxxxxx>

> ---
> changes since v6: none
> changes since v5: split out mfd/mt6397/core.h
> changes since v4: none
> changes since v3: none
> changes since v2: none (=v2 part 5)
> ---
>  drivers/power/reset/Kconfig           | 10 +++
>  drivers/power/reset/Makefile          |  1 +
>  drivers/power/reset/mt6323-poweroff.c | 97 +++++++++++++++++++++++++++
>  3 files changed, 108 insertions(+)
>  create mode 100644 drivers/power/reset/mt6323-poweroff.c
> 
> diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
> index a564237278ff..c721939767eb 100644
> --- a/drivers/power/reset/Kconfig
> +++ b/drivers/power/reset/Kconfig
> @@ -140,6 +140,16 @@ config POWER_RESET_LTC2952
>  	  This driver supports an external powerdown trigger and board power
>  	  down via the LTC2952. Bindings are made in the device tree.
>  
> +config POWER_RESET_MT6323
> +       bool "MediaTek MT6323 power-off driver"
> +       depends on MFD_MT6397
> +       help
> +         The power-off driver is responsible for externally shutdown down
> +         the power of a remote MediaTek SoC MT6323 is connected to through
> +         controlling a tiny circuit BBPU inside MT6323 RTC.
> +
> +         Say Y if you have a board where MT6323 could be found.
> +
>  config POWER_RESET_QNAP
>  	bool "QNAP power-off driver"
>  	depends on OF_GPIO && PLAT_ORION
> diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
> index 85da3198e4e0..da37f8b851dc 100644
> --- a/drivers/power/reset/Makefile
> +++ b/drivers/power/reset/Makefile
> @@ -11,6 +11,7 @@ obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o
>  obj-$(CONFIG_POWER_RESET_GPIO_RESTART) += gpio-restart.o
>  obj-$(CONFIG_POWER_RESET_HISI) += hisi-reboot.o
>  obj-$(CONFIG_POWER_RESET_MSM) += msm-poweroff.o
> +obj-$(CONFIG_POWER_RESET_MT6323) += mt6323-poweroff.o
>  obj-$(CONFIG_POWER_RESET_QCOM_PON) += qcom-pon.o
>  obj-$(CONFIG_POWER_RESET_OCELOT_RESET) += ocelot-reset.o
>  obj-$(CONFIG_POWER_RESET_PIIX4_POWEROFF) += piix4-poweroff.o
> diff --git a/drivers/power/reset/mt6323-poweroff.c b/drivers/power/reset/mt6323-poweroff.c
> new file mode 100644
> index 000000000000..1caf43d9e46d
> --- /dev/null
> +++ b/drivers/power/reset/mt6323-poweroff.c
> @@ -0,0 +1,97 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Power off through MediaTek PMIC
> + *
> + * Copyright (C) 2018 MediaTek Inc.
> + *
> + * Author: Sean Wang <sean.wang@xxxxxxxxxxxx>
> + *
> + */
> +
> +#include <linux/err.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/mfd/mt6397/core.h>
> +#include <linux/mfd/mt6397/rtc.h>
> +
> +struct mt6323_pwrc {
> +	struct device *dev;
> +	struct regmap *regmap;
> +	u32 base;
> +};
> +
> +static struct mt6323_pwrc *mt_pwrc;
> +
> +static void mt6323_do_pwroff(void)
> +{
> +	struct mt6323_pwrc *pwrc = mt_pwrc;
> +	unsigned int val;
> +	int ret;
> +
> +	regmap_write(pwrc->regmap, pwrc->base + RTC_BBPU, RTC_BBPU_KEY);
> +	regmap_write(pwrc->regmap, pwrc->base + RTC_WRTGR, 1);
> +
> +	ret = regmap_read_poll_timeout(pwrc->regmap,
> +					pwrc->base + RTC_BBPU, val,
> +					!(val & RTC_BBPU_CBUSY),
> +					MTK_RTC_POLL_DELAY_US,
> +					MTK_RTC_POLL_TIMEOUT);
> +	if (ret)
> +		dev_err(pwrc->dev, "failed to write BBPU: %d\n", ret);
> +
> +	/* Wait some time until system down, otherwise, notice with a warn */
> +	mdelay(1000);
> +
> +	WARN_ONCE(1, "Unable to power off system\n");
> +}
> +
> +static int mt6323_pwrc_probe(struct platform_device *pdev)
> +{
> +	struct mt6397_chip *mt6397_chip = dev_get_drvdata(pdev->dev.parent);
> +	struct mt6323_pwrc *pwrc;
> +	struct resource *res;
> +
> +	pwrc = devm_kzalloc(&pdev->dev, sizeof(*pwrc), GFP_KERNEL);
> +	if (!pwrc)
> +		return -ENOMEM;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	pwrc->base = res->start;
> +	pwrc->regmap = mt6397_chip->regmap;
> +	pwrc->dev = &pdev->dev;
> +	mt_pwrc = pwrc;
> +
> +	pm_power_off = &mt6323_do_pwroff;
> +
> +	return 0;
> +}
> +
> +static int mt6323_pwrc_remove(struct platform_device *pdev)
> +{
> +	if (pm_power_off == &mt6323_do_pwroff)
> +		pm_power_off = NULL;
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id mt6323_pwrc_dt_match[] = {
> +	{ .compatible = "mediatek,mt6323-pwrc" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, mt6323_pwrc_dt_match);
> +
> +static struct platform_driver mt6323_pwrc_driver = {
> +	.probe          = mt6323_pwrc_probe,
> +	.remove         = mt6323_pwrc_remove,
> +	.driver         = {
> +		.name   = "mt6323-pwrc",
> +		.of_match_table = mt6323_pwrc_dt_match,
> +	},
> +};
> +
> +module_platform_driver(mt6323_pwrc_driver);
> +
> +MODULE_DESCRIPTION("Poweroff driver for MT6323 PMIC");
> +MODULE_AUTHOR("Sean Wang <sean.wang@xxxxxxxxxxxx>");
> +MODULE_LICENSE("GPL v2");