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

[Marcin Niestroj <m.niestroj-z3quKL4iOrmQ6ZAhV5LmOA@public.gmane.org>]

Hi,

On 06.04.2016 21:11, Tony Lindgren wrote:
> * 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?

Looks ok for omap1. ARCH_OMAP1 selects ARCH_REQUIRE_GPIOLIB, which
selects GPIOLIB.

Best regards,
Marcin

>
> 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
>>

-- 
Marcin Niestroj
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