Commit 04dcadb8 authored by Valentin Caron's avatar Valentin Caron Committed by Alexandre Belloni
Browse files

rtc: stm32: add alarm A out feature 



STM32 RTC can pulse some SOC pins when an RTC alarm expires.
This patch adds this functionality for alarm A. The pulse can out on three
pins RTC_OUT1, RTC_OUT2, RTC_OUT2_RMP (PC13, PB2, PI8 on stm32mp15)
(PC13, PB2, PI1 on stm32mp13) (PC13, PF4/PF6, PI8 on stm32mp25).

This patch only adds the functionality for devices which are using
st,stm32mp1-rtc and st,stm32mp25-rtc compatible.

Add "alarm-a" in pinmux functions.

Signed-off-by: default avatarValentin Caron <valentin.caron@foss.st.com>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240722160022.454226-5-valentin.caron@foss.st.com


Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent bb7b0df2

drivers/rtc/rtc-stm32.c

+60 −0
Original line number Diff line number Diff line
@@ -47,8 +47,10 @@ 
#define STM32_RTC_CR_ALRAE		BIT(8)

#define STM32_RTC_CR_ALRAIE		BIT(12)

#define STM32_RTC_CR_OSEL		GENMASK(22, 21)

#define STM32_RTC_CR_OSEL_ALARM_A	FIELD_PREP(STM32_RTC_CR_OSEL, 0x01)

#define STM32_RTC_CR_COE		BIT(23)

#define STM32_RTC_CR_TAMPOE		BIT(26)

#define STM32_RTC_CR_TAMPALRM_TYPE	BIT(30)

#define STM32_RTC_CR_OUT2EN		BIT(31)



/* STM32_RTC_ISR/STM32_RTC_ICSR bit fields */
@@ -158,6 +160,7 @@ struct stm32_rtc_data { 
	bool need_accuracy;

	bool rif_protected;

	bool has_lsco;

	bool has_alarm_out;

};



struct stm32_rtc {
@@ -245,6 +248,47 @@ struct stm32_rtc_pinmux_func { 
	int (*action)(struct pinctrl_dev *pctl_dev, unsigned int pin);

};



static int stm32_rtc_pinmux_action_alarm(struct pinctrl_dev *pctldev, unsigned int pin)

{

	struct stm32_rtc *rtc = pinctrl_dev_get_drvdata(pctldev);

	struct stm32_rtc_registers regs = rtc->data->regs;

	unsigned int cr = readl_relaxed(rtc->base + regs.cr);

	unsigned int cfgr = readl_relaxed(rtc->base + regs.cfgr);



	if (!rtc->data->has_alarm_out)

		return -EPERM;



	cr &= ~STM32_RTC_CR_OSEL;

	cr |= STM32_RTC_CR_OSEL_ALARM_A;

	cr &= ~STM32_RTC_CR_TAMPOE;

	cr &= ~STM32_RTC_CR_COE;

	cr &= ~STM32_RTC_CR_TAMPALRM_TYPE;



	switch (pin) {

	case OUT1:

		cr &= ~STM32_RTC_CR_OUT2EN;

		cfgr &= ~STM32_RTC_CFGR_OUT2_RMP;

		break;

	case OUT2:

		cr |= STM32_RTC_CR_OUT2EN;

		cfgr &= ~STM32_RTC_CFGR_OUT2_RMP;

		break;

	case OUT2_RMP:

		cr |= STM32_RTC_CR_OUT2EN;

		cfgr |= STM32_RTC_CFGR_OUT2_RMP;

		break;

	default:

		return -EINVAL;

	}



	stm32_rtc_wpr_unlock(rtc);

	writel_relaxed(cr, rtc->base + regs.cr);

	writel_relaxed(cfgr, rtc->base + regs.cfgr);

	stm32_rtc_wpr_lock(rtc);



	return 0;

}



static int stm32_rtc_pinmux_lsco_available(struct pinctrl_dev *pctldev, unsigned int pin)

{

	struct stm32_rtc *rtc = pinctrl_dev_get_drvdata(pctldev);
@@ -307,6 +351,7 @@ static int stm32_rtc_pinmux_action_lsco(struct pinctrl_dev *pctldev, unsigned in 


static const struct stm32_rtc_pinmux_func stm32_rtc_pinmux_functions[] = {

	STM32_RTC_PINMUX("lsco", &stm32_rtc_pinmux_action_lsco, "out1", "out2_rmp"),

	STM32_RTC_PINMUX("alarm-a", &stm32_rtc_pinmux_action_alarm, "out1", "out2", "out2_rmp"),

};



static int stm32_rtc_pinmux_get_functions_count(struct pinctrl_dev *pctldev)
@@ -763,6 +808,7 @@ static const struct stm32_rtc_data stm32_rtc_data = { 
	.need_accuracy = false,

	.rif_protected = false,

	.has_lsco = false,

	.has_alarm_out = false,

	.regs = {

		.tr = 0x00,

		.dr = 0x04,
@@ -788,6 +834,7 @@ static const struct stm32_rtc_data stm32h7_rtc_data = { 
	.need_accuracy = false,

	.rif_protected = false,

	.has_lsco = false,

	.has_alarm_out = false,

	.regs = {

		.tr = 0x00,

		.dr = 0x04,
@@ -822,6 +869,7 @@ static const struct stm32_rtc_data stm32mp1_data = { 
	.need_accuracy = true,

	.rif_protected = false,

	.has_lsco = true,

	.has_alarm_out = true,

	.regs = {

		.tr = 0x00,

		.dr = 0x04,
@@ -847,6 +895,7 @@ static const struct stm32_rtc_data stm32mp25_data = { 
	.need_accuracy = true,

	.rif_protected = true,

	.has_lsco = true,

	.has_alarm_out = true,

	.regs = {

		.tr = 0x00,

		.dr = 0x04,
@@ -878,6 +927,17 @@ MODULE_DEVICE_TABLE(of, stm32_rtc_of_match); 
static void stm32_rtc_clean_outs(struct stm32_rtc *rtc)

{

	struct stm32_rtc_registers regs = rtc->data->regs;

	unsigned int cr = readl_relaxed(rtc->base + regs.cr);



	cr &= ~STM32_RTC_CR_OSEL;

	cr &= ~STM32_RTC_CR_TAMPOE;

	cr &= ~STM32_RTC_CR_COE;

	cr &= ~STM32_RTC_CR_TAMPALRM_TYPE;

	cr &= ~STM32_RTC_CR_OUT2EN;



	stm32_rtc_wpr_unlock(rtc);

	writel_relaxed(cr, rtc->base + regs.cr);

	stm32_rtc_wpr_lock(rtc);



	if (regs.cfgr != UNDEF_REG) {

		unsigned int cfgr = readl_relaxed(rtc->base + regs.cfgr);