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Commit b72252b6 authored by Amelie Delaunay's avatar Amelie Delaunay Committed by Alexandre Belloni
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rtc: stm32: add stm32mp1 rtc support 



This patch adds support for stm32mp1 RTC.
Some common registers with previous RTC version have a different offset.
It is the case for Control Register (CR) and ALaRMA Register (ALRMAR).
There are also new registers regarding event flags: now, Alarm event flag
is in Status Register (SR) and write 1 in Status Clear Register (SCR) is
required to clear the event.

Signed-off-by: default avatarAmelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent 5c4554d6

drivers/rtc/rtc-stm32.c

+89 −14
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include <linux/mfd/syscon.h>

#include <linux/module.h>

#include <linux/of_device.h>

#include <linux/pm_wakeirq.h>

#include <linux/regmap.h>

#include <linux/rtc.h>
@@ -39,7 +40,7 @@ 
#define STM32_RTC_CR_ALRAE		BIT(8)

#define STM32_RTC_CR_ALRAIE		BIT(12)



/* STM32_RTC_ISR bit fields */

/* STM32_RTC_ISR/STM32_RTC_ICSR bit fields */

#define STM32_RTC_ISR_ALRAWF		BIT(0)

#define STM32_RTC_ISR_INITS		BIT(4)

#define STM32_RTC_ISR_RSF		BIT(5)
@@ -71,21 +72,36 @@ 
#define STM32_RTC_ALRMXR_WDAY		GENMASK(27, 24)

#define STM32_RTC_ALRMXR_DATE_MASK	BIT(31)



/* STM32_RTC_SR/_SCR bit fields */

#define STM32_RTC_SR_ALRA		BIT(0)



/* STM32_RTC_VERR bit fields */

#define STM32_RTC_VERR_MINREV_SHIFT	0

#define STM32_RTC_VERR_MINREV		GENMASK(3, 0)

#define STM32_RTC_VERR_MAJREV_SHIFT	4

#define STM32_RTC_VERR_MAJREV		GENMASK(7, 4)



/* STM32_RTC_WPR key constants */

#define RTC_WPR_1ST_KEY			0xCA

#define RTC_WPR_2ND_KEY			0x53

#define RTC_WPR_WRONG_KEY		0xFF



/* Max STM32 RTC register offset is 0x3FC */

#define UNDEF_REG			0xFFFF



struct stm32_rtc;



struct stm32_rtc_registers {

	u8 tr;

	u8 dr;

	u8 cr;

	u8 isr;

	u8 prer;

	u8 alrmar;

	u8 wpr;

	u16 tr;

	u16 dr;

	u16 cr;

	u16 isr;

	u16 prer;

	u16 alrmar;

	u16 wpr;

	u16 sr;

	u16 scr;

	u16 verr;

};



struct stm32_rtc_events {
@@ -98,6 +114,7 @@ struct stm32_rtc_data { 
	void (*clear_events)(struct stm32_rtc *rtc, unsigned int flags);

	bool has_pclk;

	bool need_dbp;

	bool has_wakeirq;

};



struct stm32_rtc {
@@ -110,6 +127,7 @@ struct stm32_rtc { 
	struct clk *rtc_ck;

	const struct stm32_rtc_data *data;

	int irq_alarm;

	int wakeirq_alarm;

};



static void stm32_rtc_wpr_unlock(struct stm32_rtc *rtc)
@@ -193,7 +211,7 @@ static irqreturn_t stm32_rtc_alarm_irq(int irq, void *dev_id) 


	mutex_lock(&rtc->rtc_dev->ops_lock);



	status = readl_relaxed(rtc->base + regs->isr);

	status = readl_relaxed(rtc->base + regs->sr);

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



	if ((status & evts->alra) &&
@@ -325,7 +343,7 @@ static int stm32_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 


	alrmar = readl_relaxed(rtc->base + regs->alrmar);

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

	status = readl_relaxed(rtc->base + regs->isr);

	status = readl_relaxed(rtc->base + regs->sr);



	if (alrmar & STM32_RTC_ALRMXR_DATE_MASK) {

		/*
@@ -533,6 +551,7 @@ static void stm32_rtc_clear_events(struct stm32_rtc *rtc, 
static const struct stm32_rtc_data stm32_rtc_data = {

	.has_pclk = false,

	.need_dbp = true,

	.has_wakeirq = false,

	.regs = {

		.tr = 0x00,

		.dr = 0x04,
@@ -541,6 +560,9 @@ static const struct stm32_rtc_data stm32_rtc_data = { 
		.prer = 0x10,

		.alrmar = 0x1C,

		.wpr = 0x24,

		.sr = 0x0C, /* set to ISR offset to ease alarm management */

		.scr = UNDEF_REG,

		.verr = UNDEF_REG,

	},

	.events = {

		.alra = STM32_RTC_ISR_ALRAF,
@@ -551,6 +573,7 @@ static const struct stm32_rtc_data stm32_rtc_data = { 
static const struct stm32_rtc_data stm32h7_rtc_data = {

	.has_pclk = true,

	.need_dbp = true,

	.has_wakeirq = false,

	.regs = {

		.tr = 0x00,

		.dr = 0x04,
@@ -559,6 +582,9 @@ static const struct stm32_rtc_data stm32h7_rtc_data = { 
		.prer = 0x10,

		.alrmar = 0x1C,

		.wpr = 0x24,

		.sr = 0x0C, /* set to ISR offset to ease alarm management */

		.scr = UNDEF_REG,

		.verr = UNDEF_REG,

	},

	.events = {

		.alra = STM32_RTC_ISR_ALRAF,
@@ -566,9 +592,41 @@ static const struct stm32_rtc_data stm32h7_rtc_data = { 
	.clear_events = stm32_rtc_clear_events,

};



static void stm32mp1_rtc_clear_events(struct stm32_rtc *rtc,

				      unsigned int flags)

{

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



	/* Flags are cleared by writing 1 in RTC_SCR */

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

}



static const struct stm32_rtc_data stm32mp1_data = {

	.has_pclk = true,

	.need_dbp = false,

	.has_wakeirq = true,

	.regs = {

		.tr = 0x00,

		.dr = 0x04,

		.cr = 0x18,

		.isr = 0x0C, /* named RTC_ICSR on stm32mp1 */

		.prer = 0x10,

		.alrmar = 0x40,

		.wpr = 0x24,

		.sr = 0x50,

		.scr = 0x5C,

		.verr = 0x3F4,

	},

	.events = {

		.alra = STM32_RTC_SR_ALRA,

	},

	.clear_events = stm32mp1_rtc_clear_events,

};



static const struct of_device_id stm32_rtc_of_match[] = {

	{ .compatible = "st,stm32-rtc", .data = &stm32_rtc_data },

	{ .compatible = "st,stm32h7-rtc", .data = &stm32h7_rtc_data },

	{ .compatible = "st,stm32mp1-rtc", .data = &stm32mp1_data },

	{}

};

MODULE_DEVICE_TABLE(of, stm32_rtc_of_match);
@@ -727,12 +785,19 @@ static int stm32_rtc_probe(struct platform_device *pdev) 
		goto err;

	}



	platform_set_drvdata(pdev, rtc);



	ret = device_init_wakeup(&pdev->dev, true);

	if (rtc->data->has_wakeirq) {

		rtc->wakeirq_alarm = platform_get_irq(pdev, 1);

		if (rtc->wakeirq_alarm <= 0)

			ret = rtc->wakeirq_alarm;

		else

			ret = dev_pm_set_dedicated_wake_irq(&pdev->dev,

							    rtc->wakeirq_alarm);

	}

	if (ret)

		dev_warn(&pdev->dev,

			 "alarm won't be able to wake up the system");

		dev_warn(&pdev->dev, "alarm can't wake up the system: %d", ret);



	platform_set_drvdata(pdev, rtc);



	rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, pdev->name,

						&stm32_rtc_ops, THIS_MODULE);
@@ -760,6 +825,14 @@ static int stm32_rtc_probe(struct platform_device *pdev) 
	if (!(readl_relaxed(rtc->base + regs->isr) & STM32_RTC_ISR_INITS))

		dev_warn(&pdev->dev, "Date/Time must be initialized\n");



	if (regs->verr != UNDEF_REG) {

		u32 ver = readl_relaxed(rtc->base + regs->verr);



		dev_info(&pdev->dev, "registered rev:%d.%d\n",

			 (ver >> STM32_RTC_VERR_MAJREV_SHIFT) & 0xF,

			 (ver >> STM32_RTC_VERR_MINREV_SHIFT) & 0xF);

	}



	return 0;

err:

	if (rtc->data->has_pclk)
@@ -769,6 +842,7 @@ static int stm32_rtc_probe(struct platform_device *pdev) 
	if (rtc->data->need_dbp)

		regmap_update_bits(rtc->dbp, rtc->dbp_reg, rtc->dbp_mask, 0);



	dev_pm_clear_wake_irq(&pdev->dev);

	device_init_wakeup(&pdev->dev, false);



	return ret;
@@ -795,6 +869,7 @@ static int stm32_rtc_remove(struct platform_device *pdev) 
	if (rtc->data->need_dbp)

		regmap_update_bits(rtc->dbp, rtc->dbp_reg, rtc->dbp_mask, 0);



	dev_pm_clear_wake_irq(&pdev->dev);

	device_init_wakeup(&pdev->dev, false);



	return 0;