Re: [PATCH v2] rtc: omap: Support ext_wakeup configuration

[Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>]

* Marcin Niestroj <m.niestroj-z3quKL4iOrmQ6ZAhV5LmOA@public.gmane.org> [160406 09:34]:
> Support configuration of ext_wakeup sources. This patch makes it
> possible to enable ext_wakeup (and set it's polarity), depending on
> board configuration. AM335x's dedicated PMIC (tps65217) uses ext_wakeup
> in SLEEP mode (RTC-only) to notify about power-button presses. Handling
> power-button presses enables to recover from RTC-only power states
> correctly.
> 
> Implementation uses gpiochip to utilize standard bindings. However,
> configuration is possible only using device-tree (no runtime changes).

Hey looks good to me, adding linux-omap list to Cc.

Can you please check that the "depends on GPIOLIB" does not disable
the RTC driver for omap1?

Regards,

Tony

> Signed-off-by: Marcin Niestroj <m.niestroj-z3quKL4iOrmQ6ZAhV5LmOA@public.gmane.org>
> ---
>  Documentation/devicetree/bindings/rtc/rtc-omap.txt |  18 ++-
>  drivers/rtc/Kconfig                                |   2 +-
>  drivers/rtc/rtc-omap.c                             | 137 ++++++++++++++++++++-
>  3 files changed, 154 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/rtc/rtc-omap.txt b/Documentation/devicetree/bindings/rtc/rtc-omap.txt
> index bf7d11a..4a7738e 100644
> --- a/Documentation/devicetree/bindings/rtc/rtc-omap.txt
> +++ b/Documentation/devicetree/bindings/rtc/rtc-omap.txt
> @@ -18,8 +18,12 @@ Optional properties:
>    through pmic_power_en
>  - clocks: Any internal or external clocks feeding in to rtc
>  - clock-names: Corresponding names of the clocks
> +- gpio-controller: Mark as gpio controller when using ext_wakeup
> +- #gpio-cells: Should be set to 2
> +- ngpios: Number of ext_wakeup sources supported by processor (board)
> +- ext-wakeup-gpios: List of ext_wakeup sources to configure
>  
> -Example:
> +Examples:
>  
>  rtc@1c23000 {
>  	compatible = "ti,da830-rtc";
> @@ -31,3 +35,15 @@ rtc@1c23000 {
>  	clocks = <&clk_32k_rtc>, <&clk_32768_ck>;
>  	clock-names = "ext-clk", "int-clk";
>  };
> +
> +rtc: rtc@44e3e000 {
> +	compatible = "ti,am3352-rtc", "ti,da830-rtc";
> +	reg = <0x44e3e000 0x1000>;
> +	interrupts = <75
> +		      76>;
> +	system-power-controller;
> +	gpio-controller;
> +	#gpio-cells = <2>;
> +	ngpios = <1>;
> +	ext-wakeup-gpios = <&rtc 0 GPIO_ACTIVE_LOW>;
> +};
> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> index 3e84315..f013346 100644
> --- a/drivers/rtc/Kconfig
> +++ b/drivers/rtc/Kconfig
> @@ -1208,7 +1208,7 @@ config RTC_DRV_IMXDI
>  
>  config RTC_DRV_OMAP
>  	tristate "TI OMAP Real Time Clock"
> -	depends on ARCH_OMAP || ARCH_DAVINCI || COMPILE_TEST
> +	depends on (ARCH_OMAP || ARCH_DAVINCI || COMPILE_TEST) && GPIOLIB
>  	help
>  	  Say "yes" here to support the on chip real time clock
>  	  present on TI OMAP1, AM33xx, DA8xx/OMAP-L13x, AM43xx and DRA7xx.
> diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
> index ec2e9c5..56c7155 100644
> --- a/drivers/rtc/rtc-omap.c
> +++ b/drivers/rtc/rtc-omap.c
> @@ -26,6 +26,8 @@
>  #include <linux/pm_runtime.h>
>  #include <linux/io.h>
>  #include <linux/clk.h>
> +#include <linux/gpio/driver.h>
> +#include <linux/gpio/consumer.h>
>  
>  /*
>   * The OMAP RTC is a year/month/day/hours/minutes/seconds BCD clock
> @@ -114,7 +116,11 @@
>  #define OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN	BIT(1)
>  
>  /* OMAP_RTC_PMIC bit fields: */
> -#define OMAP_RTC_PMIC_POWER_EN_EN	BIT(16)
> +#define OMAP_RTC_PMIC_POWER_EN_EN		BIT(16)
> +#define OMAP_RTC_PMIC_EXT_WAKEUP_EN(x)		(BIT(x))
> +#define OMAP_RTC_PMIC_EXT_WAKEUP_POL(x)		(BIT(x) << 4)
> +#define OMAP_RTC_PMIC_EXT_WAKEUP_EN_MASK	(0x0F)
> +#define OMAP_RTC_PMIC_EXT_WAKEUP_POL_MASK	(0x0F << 4)
>  
>  /* OMAP_RTC_KICKER values */
>  #define	KICK0_VALUE			0x83e70b13
> @@ -141,6 +147,7 @@ struct omap_rtc {
>  	bool is_pmic_controller;
>  	bool has_ext_clk;
>  	const struct omap_rtc_device_type *type;
> +	struct gpio_chip gpio_chip;
>  };
>  
>  static inline u8 rtc_read(struct omap_rtc *rtc, unsigned int reg)
> @@ -183,6 +190,104 @@ static void default_rtc_lock(struct omap_rtc *rtc)
>  {
>  }
>  
> +static int omap_rtc_gpio_request(struct gpio_chip *chip,
> +				unsigned int offset)
> +{
> +	struct omap_rtc *rtc = gpiochip_get_data(chip);
> +	u32 val;
> +
> +	rtc->type->unlock(rtc);
> +
> +	val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
> +	val |= OMAP_RTC_PMIC_EXT_WAKEUP_EN(offset);
> +	rtc_writel(rtc, OMAP_RTC_PMIC_REG, val);
> +
> +	rtc->type->lock(rtc);
> +
> +	return 0;
> +}
> +
> +static void omap_rtc_gpio_free(struct gpio_chip *chip,
> +			unsigned int offset)
> +{
> +	struct omap_rtc *rtc = gpiochip_get_data(chip);
> +	u32 val;
> +
> +	rtc->type->unlock(rtc);
> +
> +	val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
> +	val &= ~OMAP_RTC_PMIC_EXT_WAKEUP_EN(offset);
> +	rtc_writel(rtc, OMAP_RTC_PMIC_REG, val);
> +
> +	rtc->type->lock(rtc);
> +}
> +
> +static int omap_rtc_gpio_get_direction(struct gpio_chip *chip,
> +				unsigned int offset)
> +{
> +	return 1; /* Always in */
> +}
> +
> +
> +static int omap_rtc_gpio_direction_input(struct gpio_chip *chip,
> +					unsigned int offset)
> +{
> +	return 0;
> +}
> +
> +static int omap_rtc_gpio_get(struct gpio_chip *chip, unsigned int offset)
> +{
> +	return 0;
> +}
> +
> +/*
> + * Note: This function is called only when setting ext_wakeup polarity
> + * with omap_rtc_gpio_set_polarity
> + */
> +static void omap_rtc_gpio_set(struct gpio_chip *chip, unsigned int offset,
> +			int value)
> +{
> +	struct omap_rtc *rtc = gpiochip_get_data(chip);
> +	u32 val;
> +
> +	rtc->type->unlock(rtc);
> +
> +	val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
> +	if (value)
> +		val |= OMAP_RTC_PMIC_EXT_WAKEUP_POL(offset);
> +	else
> +		val &= ~OMAP_RTC_PMIC_EXT_WAKEUP_POL(offset);
> +	rtc_writel(rtc, OMAP_RTC_PMIC_REG, val);
> +
> +	rtc->type->lock(rtc);
> +}
> +
> +static void omap_rtc_gpio_set_polarity(struct gpio_descs *ext_wakeup)
> +{
> +	struct gpio_desc *desc;
> +	int i;
> +
> +	for (i = 0; i < ext_wakeup->ndescs; i++) {
> +		desc = ext_wakeup->desc[i];
> +		gpiod_set_raw_value_cansleep(desc,
> +					gpiod_is_active_low(desc));
> +	}
> +}
> +
> +static struct gpio_chip template_chip = {
> +	.label			= "omap-rtc-gpio",
> +	.owner			= THIS_MODULE,
> +	.request		= omap_rtc_gpio_request,
> +	.free			= omap_rtc_gpio_free,
> +	.get_direction		= omap_rtc_gpio_get_direction,
> +	.direction_input	= omap_rtc_gpio_direction_input,
> +	.get			= omap_rtc_gpio_get,
> +	.set			= omap_rtc_gpio_set,
> +	.base			= -1,
> +	.ngpio			= 4,
> +	.can_sleep		= true,
> +};
> +
>  /*
>   * We rely on the rtc framework to handle locking (rtc->ops_lock),
>   * so the only other requirement is that register accesses which
> @@ -533,6 +638,8 @@ static int omap_rtc_probe(struct platform_device *pdev)
>  	const struct platform_device_id *id_entry;
>  	const struct of_device_id *of_id;
>  	int ret;
> +	struct gpio_descs *ext_wakeup;
> +	u32 ngpios = 0;
>  
>  	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
>  	if (!rtc)
> @@ -544,6 +651,10 @@ static int omap_rtc_probe(struct platform_device *pdev)
>  		rtc->is_pmic_controller = rtc->type->has_pmic_mode &&
>  				of_property_read_bool(pdev->dev.of_node,
>  						"system-power-controller");
> +		ret = of_property_read_u32(pdev->dev.of_node, "ngpios",
> +					&ngpios);
> +		if (ret)
> +			ngpios = 0;
>  	} else {
>  		id_entry = platform_get_device_id(pdev);
>  		rtc->type = (void *)id_entry->driver_data;
> @@ -577,6 +688,30 @@ static int omap_rtc_probe(struct platform_device *pdev)
>  	pm_runtime_enable(&pdev->dev);
>  	pm_runtime_get_sync(&pdev->dev);
>  
> +	if (ngpios > 0) {
> +		rtc->gpio_chip = template_chip;
> +		rtc->gpio_chip.parent = &pdev->dev;
> +		rtc->gpio_chip.ngpio = ngpios;
> +		ret = devm_gpiochip_add_data(&pdev->dev, &rtc->gpio_chip,
> +					rtc);
> +		if (ret < 0) {
> +			dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
> +				ret);
> +			return ret;
> +		}
> +
> +		ext_wakeup = devm_gpiod_get_array_optional(&pdev->dev,
> +						"ext-wakeup", GPIOD_IN);
> +		if (IS_ERR(ext_wakeup)) {
> +			ret = PTR_ERR(ext_wakeup);
> +			dev_err(&pdev->dev,
> +				"ext-wakeup request failed, ret %d\n", ret);
> +			return ret;
> +		}
> +		if (ext_wakeup)
> +			omap_rtc_gpio_set_polarity(ext_wakeup);
> +	}
> +
>  	rtc->type->unlock(rtc);
>  
>  	/*
> -- 
> 2.8.0
> 
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