Re: [PATCH v2 4/6] power: reset: Add poweroff driver for ATC260x PMICs

[Cristian Ciocaltea <cristian.ciocaltea@gmail.com>]

Hi Sebastian,

Thanks for the review!

On Mon, Aug 24, 2020 at 04:41:13PM +0200, Sebastian Reichel wrote:
> Hi,
> 
> On Sat, Aug 22, 2020 at 01:19:50AM +0300, Cristian Ciocaltea wrote:
> > This driver provides poweroff and reboot support for a system through
> > the ATC2603C and ATC2609A chip variants of the Actions Semi ATC260x
> > family of PMICs.
> > 
> > Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
> > ---
> >  drivers/power/reset/Kconfig            |   8 +-
> >  drivers/power/reset/Makefile           |   1 +
> >  drivers/power/reset/atc260x-poweroff.c | 274 +++++++++++++++++++++++++
> >  3 files changed, 282 insertions(+), 1 deletion(-)
> >  create mode 100644 drivers/power/reset/atc260x-poweroff.c
> > 
> > diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
> > index 0a1fb5c74f83..df6c3676b892 100644
> > --- a/drivers/power/reset/Kconfig
> > +++ b/drivers/power/reset/Kconfig
> > @@ -39,6 +39,13 @@ config POWER_RESET_AT91_SAMA5D2_SHDWC
> >  	  This driver supports the alternate shutdown controller for some Atmel
> >  	  SAMA5 SoCs. It is present for example on SAMA5D2 SoC.
> >  
> > +config POWER_RESET_ATC260X
> > +	tristate "Actions Semi ATC260x PMIC power-off driver"
> > +	depends on MFD_ATC260X
> > +	help
> > +	  This driver provides power-off and restart support for a system
> > +	  through Actions Semi ATC260x series PMICs.
> > +
> >  config POWER_RESET_AXXIA
> >  	bool "LSI Axxia reset driver"
> >  	depends on ARCH_AXXIA
> > @@ -285,4 +292,3 @@ config NVMEM_REBOOT_MODE
> >  	  action according to the mode.
> >  
> >  endif
> > -
> > diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
> > index c51eceba9ea3..829df1157540 100644
> > --- a/drivers/power/reset/Makefile
> > +++ b/drivers/power/reset/Makefile
> > @@ -3,6 +3,7 @@ obj-$(CONFIG_POWER_RESET_AS3722) += as3722-poweroff.o
> >  obj-$(CONFIG_POWER_RESET_AT91_POWEROFF) += at91-poweroff.o
> >  obj-$(CONFIG_POWER_RESET_AT91_RESET) += at91-reset.o
> >  obj-$(CONFIG_POWER_RESET_AT91_SAMA5D2_SHDWC) += at91-sama5d2_shdwc.o
> > +obj-$(CONFIG_POWER_RESET_ATC260X) += atc260x-poweroff.o
> >  obj-$(CONFIG_POWER_RESET_AXXIA) += axxia-reset.o
> >  obj-$(CONFIG_POWER_RESET_BRCMKONA) += brcm-kona-reset.o
> >  obj-$(CONFIG_POWER_RESET_BRCMSTB) += brcmstb-reboot.o
> > diff --git a/drivers/power/reset/atc260x-poweroff.c b/drivers/power/reset/atc260x-poweroff.c
> > new file mode 100644
> > index 000000000000..81a99e7e4a91
> > --- /dev/null
> > +++ b/drivers/power/reset/atc260x-poweroff.c
> > @@ -0,0 +1,274 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Poweroff & reset driver for Actions Semi ATC260x PMICs
> > + *
> > + * Copyright (c) 2020 Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
> > + */
> > +
> > +#include <linux/delay.h>
> > +#include <linux/mfd/atc260x/core.h>
> > +#include <linux/module.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/power_supply.h>
> > +#include <linux/reboot.h>
> > +#include <linux/regmap.h>
> > +
> > +struct atc260x_pwrc {
> > +	struct device *dev;
> > +	struct regmap *regmap;
> > +	struct notifier_block restart_nb;
> > +	int (*do_poweroff)(const struct atc260x_pwrc *pwrc, bool restart);
> > +};
> > +
> > +/* Global variable needed only for pm_power_off */
> > +static struct atc260x_pwrc *atc260x_pwrc_data;
> > +
> > +static int atc2603c_do_poweroff(const struct atc260x_pwrc *pwrc, bool restart)
> > +{
> > +	int ret, deep_sleep = 0;
> > +	uint reg_mask, reg_val;
> > +
> > +	/* S4-Deep Sleep Mode is NOT available for WALL/USB power */
> > +	if (!restart && !power_supply_is_system_supplied()) {
> > +		deep_sleep = 1;
> > +		dev_info(pwrc->dev, "Enabling S4-Deep Sleep Mode");
> > +	}
> > +
> > +	/* Update wakeup sources */
> > +	reg_val = ATC2603C_PMU_SYS_CTL0_ONOFF_LONG_WK_EN |
> > +		  (restart ? ATC2603C_PMU_SYS_CTL0_RESET_WK_EN
> > +			   : ATC2603C_PMU_SYS_CTL0_ONOFF_SHORT_WK_EN);
> > +
> > +	ret = regmap_update_bits(pwrc->regmap, ATC2603C_PMU_SYS_CTL0,
> > +				 ATC2603C_PMU_SYS_CTL0_WK_ALL, reg_val);
> > +	if (ret)
> > +		dev_warn(pwrc->dev, "failed to write SYS_CTL0: %d\n", ret);
> > +
> > +	/* Update power mode */
> > +	reg_mask = ATC2603C_PMU_SYS_CTL3_EN_S2 | ATC2603C_PMU_SYS_CTL3_EN_S3;
> > +
> > +	ret = regmap_update_bits(pwrc->regmap, ATC2603C_PMU_SYS_CTL3, reg_mask,
> > +				 deep_sleep ? 0 : ATC2603C_PMU_SYS_CTL3_EN_S3);
> > +	if (ret) {
> > +		dev_err(pwrc->dev, "failed to write SYS_CTL3: %d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	/* Trigger poweroff / restart sequence */
> > +	reg_mask = restart ? ATC2603C_PMU_SYS_CTL0_RESTART_EN
> > +			   : ATC2603C_PMU_SYS_CTL1_EN_S1;
> > +	reg_val = restart ? ATC2603C_PMU_SYS_CTL0_RESTART_EN : 0;
> > +
> > +	ret = regmap_update_bits(pwrc->regmap,
> > +				 restart ? ATC2603C_PMU_SYS_CTL0 : ATC2603C_PMU_SYS_CTL1,
> > +				 reg_mask, reg_val);
> > +	if (ret) {
> > +		dev_err(pwrc->dev, "failed to write SYS_CTL%d: %d\n",
> > +			restart ? 0 : 1, ret);
> > +		return ret;
> > +	}
> > +
> > +	/* Wait for trigger completion */
> > +	mdelay(200);
> > +
> > +	return 0;
> > +}
> > +
> > +static int atc2609a_do_poweroff(const struct atc260x_pwrc *pwrc, bool restart)
> > +{
> > +	int ret, deep_sleep = 0;
> > +	uint reg_mask, reg_val;
> > +
> > +	/* S4-Deep Sleep Mode is NOT available for WALL/USB power */
> > +	if (!restart && !power_supply_is_system_supplied()) {
> > +		deep_sleep = 1;
> > +		dev_info(pwrc->dev, "Enabling S4-Deep Sleep Mode");
> > +	}
> > +
> > +	/* Update wakeup sources */
> > +	reg_val = ATC2609A_PMU_SYS_CTL0_ONOFF_LONG_WK_EN |
> > +		  (restart ? ATC2609A_PMU_SYS_CTL0_RESET_WK_EN
> > +			   : ATC2609A_PMU_SYS_CTL0_ONOFF_SHORT_WK_EN);
> > +
> > +	ret = regmap_update_bits(pwrc->regmap, ATC2609A_PMU_SYS_CTL0,
> > +				 ATC2609A_PMU_SYS_CTL0_WK_ALL, reg_val);
> > +	if (ret)
> > +		dev_warn(pwrc->dev, "failed to write SYS_CTL0: %d\n", ret);
> > +
> > +	/* Update power mode */
> > +	reg_mask = ATC2609A_PMU_SYS_CTL3_EN_S2 | ATC2609A_PMU_SYS_CTL3_EN_S3;
> > +
> > +	ret = regmap_update_bits(pwrc->regmap, ATC2609A_PMU_SYS_CTL3, reg_mask,
> > +				 deep_sleep ? 0 : ATC2609A_PMU_SYS_CTL3_EN_S3);
> > +	if (ret) {
> > +		dev_err(pwrc->dev, "failed to write SYS_CTL3: %d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	/* Trigger poweroff / restart sequence */
> > +	reg_mask = restart ? ATC2609A_PMU_SYS_CTL0_RESTART_EN
> > +			   : ATC2609A_PMU_SYS_CTL1_EN_S1;
> > +	reg_val = restart ? ATC2609A_PMU_SYS_CTL0_RESTART_EN : 0;
> > +
> > +	ret = regmap_update_bits(pwrc->regmap,
> > +				 restart ? ATC2609A_PMU_SYS_CTL0 : ATC2609A_PMU_SYS_CTL1,
> > +				 reg_mask, reg_val);
> > +	if (ret) {
> > +		dev_err(pwrc->dev, "failed to write SYS_CTL%d: %d\n",
> > +			restart ? 0 : 1, ret);
> > +		return ret;
> > +	}
> > +
> > +	/* Wait for trigger completion */
> > +	mdelay(200);
> > +
> > +	return 0;
> > +}
> > +
> > +static int atc2603c_init(const struct atc260x_pwrc *pwrc)
> > +{
> > +	int ret;
> > +
> > +	/*
> > +	 * Delay transition from S2/S3 to S1 in order to avoid
> > +	 * DDR init failure in Bootloader.
> > +	 */
> > +	ret = regmap_update_bits(pwrc->regmap, ATC2603C_PMU_SYS_CTL3,
> > +				 ATC2603C_PMU_SYS_CTL3_S2S3TOS1_TIMER_EN,
> > +				 ATC2603C_PMU_SYS_CTL3_S2S3TOS1_TIMER_EN);
> > +	if (ret)
> > +		dev_warn(pwrc->dev, "failed to write SYS_CTL3: %d\n", ret);
> > +
> > +	/* Set wakeup sources */
> > +	ret = regmap_update_bits(pwrc->regmap, ATC2603C_PMU_SYS_CTL0,
> > +				 ATC2603C_PMU_SYS_CTL0_WK_ALL,
> > +				 ATC2603C_PMU_SYS_CTL0_HDSW_WK_EN |
> > +				 ATC2603C_PMU_SYS_CTL0_ONOFF_LONG_WK_EN);
> > +	if (ret)
> > +		dev_warn(pwrc->dev, "failed to write SYS_CTL0: %d\n", ret);
> > +
> > +	return ret;
> > +}
> > +
> > +static int atc2609a_init(const struct atc260x_pwrc *pwrc)
> > +{
> > +	int ret;
> > +
> > +	/* Set wakeup sources */
> > +	ret = regmap_update_bits(pwrc->regmap, ATC2609A_PMU_SYS_CTL0,
> > +				 ATC2609A_PMU_SYS_CTL0_WK_ALL,
> > +				 ATC2609A_PMU_SYS_CTL0_HDSW_WK_EN |
> > +				 ATC2609A_PMU_SYS_CTL0_ONOFF_LONG_WK_EN);
> > +	if (ret)
> > +		dev_warn(pwrc->dev, "failed to write SYS_CTL0: %d\n", ret);
> > +
> > +	return ret;
> > +}
> > +
> > +static void atc260x_pwrc_pm_handler(void)
> > +{
> > +	atc260x_pwrc_data->do_poweroff(atc260x_pwrc_data, false);
> > +
> > +	WARN_ONCE(1, "Unable to power off system\n");
> > +}
> > +
> > +static int atc260x_pwrc_restart_handler(struct notifier_block *nb,
> > +					unsigned long mode, void *cmd)
> > +{
> > +	struct atc260x_pwrc *pwrc = container_of(nb, struct atc260x_pwrc,
> > +						 restart_nb);
> > +	pwrc->do_poweroff(pwrc, true);
> > +
> > +	return NOTIFY_DONE;
> > +}
> > +
> > +static int atc260x_pwrc_probe(struct platform_device *pdev)
> > +{
> > +	struct atc260x *atc260x = dev_get_drvdata(pdev->dev.parent);
> > +	struct atc260x_pwrc *priv;
> > +	int ret;
> > +
> > +	if (!pdev->dev.of_node)
> > +		return -ENXIO;
> > +
> > +	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> > +	if (!priv)
> > +		return -ENOMEM;
> > +
> > +	priv->dev = &pdev->dev;
> > +	priv->regmap = atc260x->regmap;
> > +	priv->restart_nb.notifier_call = atc260x_pwrc_restart_handler;
> > +	priv->restart_nb.priority = 192;
> > +
> > +	switch (atc260x->ic_type) {
> > +	case ATC2603C:
> > +		priv->do_poweroff = atc2603c_do_poweroff;
> > +		ret = atc2603c_init(priv);
> > +		break;
> > +	case ATC2609A:
> > +		priv->do_poweroff = atc2609a_do_poweroff;
> > +		ret = atc2609a_init(priv);
> > +		break;
> > +	default:
> > +		dev_err(priv->dev,
> > +			"Poweroff not supported for ATC260x PMIC type: %u\n",
> > +			atc260x->ic_type);
> > +		return -EINVAL;
> > +	}
> > +
> > +	if (ret)
> > +		return ret;
> > +
> > +	platform_set_drvdata(pdev, priv);
> > +
> > +	if (!pm_power_off) {
> > +		atc260x_pwrc_data = priv;
> > +		pm_power_off = atc260x_pwrc_pm_handler;
> > +	} else {
> > +		dev_warn(priv->dev, "Poweroff callback already assigned\n");
> > +	}
> > +
> > +	ret = register_restart_handler(&priv->restart_nb);
> > +	if (ret)
> > +		dev_err(priv->dev, "failed to register restart handler: %d\n",
> > +			ret);
> > +
> > +	return ret;
> > +}
> > +
> > +static int atc260x_pwrc_remove(struct platform_device *pdev)
> > +{
> > +	struct atc260x_pwrc *priv = platform_get_drvdata(pdev);
> > +
> > +	if (atc260x_pwrc_data == priv) {
> > +		pm_power_off = NULL;
> > +		atc260x_pwrc_data = NULL;
> > +	}
> > +
> > +	unregister_restart_handler(&priv->restart_nb);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct of_device_id atc260x_pwrc_of_match[] = {
> > +	{ .compatible = "actions,atc2603c-pwrc" },
> > +	{ .compatible = "actions,atc2609a-pwrc" },
> > +	{ /* sentinel */ }
> > +};
> > +MODULE_DEVICE_TABLE(of, atc260x_pwrc_of_match);
> > +
> > +static struct platform_driver atc260x_pwrc_driver = {
> > +	.probe = atc260x_pwrc_probe,
> > +	.remove = atc260x_pwrc_remove,
> > +	.driver = {
> > +		.name = "atc260x-pwrc",
> > +		.of_match_table = of_match_ptr(atc260x_pwrc_of_match),
> 
> drop of_match_ptr() and directly use atc260x_pwrc_of_match. Current
> code would throw unused warning for atc260x_pwrc_of_match when OF is
> disabled.

Done.

> > +	},
> > +};
> > +
> > +module_platform_driver(atc260x_pwrc_driver);
> > +
> > +MODULE_DESCRIPTION("Poweroff & reset driver for ATC260x PMICs");
> > +MODULE_AUTHOR("Cristian Ciocaltea <cristian.ciocaltea@gmail.com>");
> > +MODULE_LICENSE("GPL");
> 
> Otherwise LGTM,
> 
> -- Sebastian

Regards,
Cristi