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Subject[PATCH v3 4/4] rtc: stm32: add stm32mp1 rtc support
Date
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: Amelie Delaunay <amelie.delaunay@st.com>
---
drivers/rtc/rtc-stm32.c | 103 +++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 89 insertions(+), 14 deletions(-)

diff --git a/drivers/rtc/rtc-stm32.c b/drivers/rtc/rtc-stm32.c
index 8254e38..c5908cf 100644
--- a/drivers/rtc/rtc-stm32.c
+++ b/drivers/rtc/rtc-stm32.c
@@ -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;
--
2.7.4
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