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Subject[PATCH v3 2/2] rtc: sprd: Add Spreadtrum RTC driver
Date
This patch adds the Spreadtrum RTC driver, which embedded in the
Spreadtrum SC27xx series PMICs.

Signed-off-by: Baolin Wang <baolin.wang@spreadtrum.com>
---
Changes since v2:
- Add checking if RTC values are valid.

Changes since v1:
- Change file name.
- Should depend on the MFD parent.
- Add more help documentation.
- Remove regmap wrapper functions.
- Modify the mothod of setting alarm.
- Remove set_mmss64() method.
- Remove checking RTC power-down.
- Optimize lock/unlock alarm.
---
drivers/rtc/Kconfig | 11 +
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc-sc27xx.c | 662 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 674 insertions(+)
create mode 100644 drivers/rtc/rtc-sc27xx.c

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index e0e58f3..8c240e7 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1174,6 +1174,17 @@ config RTC_DRV_WM8350
This driver can also be built as a module. If so, the module
will be called "rtc-wm8350".

+config RTC_DRV_SC27XX
+ tristate "Spreadtrum SC27xx RTC"
+ depends on MFD_SC27XX_PMIC || COMPILE_TEST
+ help
+ If you say Y here you will get support for the RTC subsystem
+ of the Spreadtrum SC27xx series PMICs. The SC27xx series PMICs
+ includes the SC2720, SC2721, SC2723, SC2730 and SC2731 chips.
+
+ This driver can also be built as a module. If so, the module
+ will be called rtc-sc27xx.
+
config RTC_DRV_SPEAR
tristate "SPEAR ST RTC"
depends on PLAT_SPEAR || COMPILE_TEST
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 7230014..f9b857f 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -143,6 +143,7 @@ obj-$(CONFIG_RTC_DRV_S35390A) += rtc-s35390a.o
obj-$(CONFIG_RTC_DRV_S3C) += rtc-s3c.o
obj-$(CONFIG_RTC_DRV_S5M) += rtc-s5m.o
obj-$(CONFIG_RTC_DRV_SA1100) += rtc-sa1100.o
+obj-$(CONFIG_RTC_DRV_SC27XX) += rtc-sc27xx.o
obj-$(CONFIG_RTC_DRV_SH) += rtc-sh.o
obj-$(CONFIG_RTC_DRV_SIRFSOC) += rtc-sirfsoc.o
obj-$(CONFIG_RTC_DRV_SNVS) += rtc-snvs.o
diff --git a/drivers/rtc/rtc-sc27xx.c b/drivers/rtc/rtc-sc27xx.c
new file mode 100644
index 0000000..d544d52
--- /dev/null
+++ b/drivers/rtc/rtc-sc27xx.c
@@ -0,0 +1,662 @@
+/*
+ * Copyright (C) 2017 Spreadtrum Communications Inc.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+
+#define SPRD_RTC_SEC_CNT_VALUE 0x0
+#define SPRD_RTC_MIN_CNT_VALUE 0x4
+#define SPRD_RTC_HOUR_CNT_VALUE 0x8
+#define SPRD_RTC_DAY_CNT_VALUE 0xc
+#define SPRD_RTC_SEC_CNT_UPD 0x10
+#define SPRD_RTC_MIN_CNT_UPD 0x14
+#define SPRD_RTC_HOUR_CNT_UPD 0x18
+#define SPRD_RTC_DAY_CNT_UPD 0x1c
+#define SPRD_RTC_SEC_ALM_UPD 0x20
+#define SPRD_RTC_MIN_ALM_UPD 0x24
+#define SPRD_RTC_HOUR_ALM_UPD 0x28
+#define SPRD_RTC_DAY_ALM_UPD 0x2c
+#define SPRD_RTC_INT_EN 0x30
+#define SPRD_RTC_INT_RAW_STS 0x34
+#define SPRD_RTC_INT_CLR 0x38
+#define SPRD_RTC_INT_MASK_STS 0x3C
+#define SPRD_RTC_SEC_ALM_VALUE 0x40
+#define SPRD_RTC_MIN_ALM_VALUE 0x44
+#define SPRD_RTC_HOUR_ALM_VALUE 0x48
+#define SPRD_RTC_DAY_ALM_VALUE 0x4c
+#define SPRD_RTC_SPG_VALUE 0x50
+#define SPRD_RTC_SPG_UPD 0x54
+#define SPRD_RTC_SEC_AUXALM_UPD 0x60
+#define SPRD_RTC_MIN_AUXALM_UPD 0x64
+#define SPRD_RTC_HOUR_AUXALM_UPD 0x68
+#define SPRD_RTC_DAY_AUXALM_UPD 0x6c
+
+/* BIT & MASK definition for SPRD_RTC_INT_* registers */
+#define SPRD_RTC_SEC_EN BIT(0)
+#define SPRD_RTC_MIN_EN BIT(1)
+#define SPRD_RTC_HOUR_EN BIT(2)
+#define SPRD_RTC_DAY_EN BIT(3)
+#define SPRD_RTC_ALARM_EN BIT(4)
+#define SPRD_RTC_HRS_FORMAT_EN BIT(5)
+#define SPRD_RTC_AUXALM_EN BIT(6)
+#define SPRD_RTC_SPG_UPD_EN BIT(7)
+#define SPRD_RTC_SEC_UPD_EN BIT(8)
+#define SPRD_RTC_MIN_UPD_EN BIT(9)
+#define SPRD_RTC_HOUR_UPD_EN BIT(10)
+#define SPRD_RTC_DAY_UPD_EN BIT(11)
+#define SPRD_RTC_ALMSEC_UPD_EN BIT(12)
+#define SPRD_RTC_ALMMIN_UPD_EN BIT(13)
+#define SPRD_RTC_ALMHOUR_UPD_EN BIT(14)
+#define SPRD_RTC_ALMDAY_UPD_EN BIT(15)
+#define SPRD_RTC_INT_MASK GENMASK(15, 0)
+
+#define SPRD_RTC_TIME_INT_MASK \
+ (SPRD_RTC_SEC_UPD_EN | SPRD_RTC_MIN_UPD_EN | \
+ SPRD_RTC_HOUR_UPD_EN | SPRD_RTC_DAY_UPD_EN)
+
+#define SPRD_RTC_ALMTIME_INT_MASK \
+ (SPRD_RTC_ALMSEC_UPD_EN | SPRD_RTC_ALMMIN_UPD_EN | \
+ SPRD_RTC_ALMHOUR_UPD_EN | SPRD_RTC_ALMDAY_UPD_EN)
+
+#define SPRD_RTC_ALM_INT_MASK \
+ (SPRD_RTC_SEC_EN | SPRD_RTC_MIN_EN | \
+ SPRD_RTC_HOUR_EN | SPRD_RTC_DAY_EN | \
+ SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN)
+
+/* second/minute/hour/day values mask definition */
+#define SPRD_RTC_SEC_MASK GENMASK(5, 0)
+#define SPRD_RTC_MIN_MASK GENMASK(5, 0)
+#define SPRD_RTC_HOUR_MASK GENMASK(4, 0)
+#define SPRD_RTC_DAY_MASK GENMASK(15, 0)
+
+/* alarm lock definition for SPRD_RTC_SPG_UPD register */
+#define SPRD_RTC_ALMLOCK_MASK GENMASK(7, 0)
+#define SPRD_RTC_ALM_UNLOCK 0xa5
+#define SPRD_RTC_ALM_LOCK (~SPRD_RTC_ALM_UNLOCK & \
+ SPRD_RTC_ALMLOCK_MASK)
+
+/* SPG values definition for SPRD_RTC_SPG_UPD register */
+#define SPRD_RTC_POWEROFF_ALM_FLAG BIT(8)
+#define SPRD_RTC_POWER_RESET_FLAG BIT(9)
+
+/* timeout of synchronizing time and alarm registers (us) */
+#define SPRD_RTC_POLL_TIMEOUT 200000
+#define SPRD_RTC_POLL_DELAY_US 20000
+
+struct sprd_rtc {
+ struct rtc_device *rtc;
+ struct regmap *regmap;
+ struct device *dev;
+ u32 base;
+ int irq;
+ bool valid;
+};
+
+/*
+ * The Spreadtrum RTC controller has 3 groups registers, including time, normal
+ * alarm and auxiliary alarm. The time group registers are used to set RTC time,
+ * the normal alarm registers are used to set normal alarm, and the auxiliary
+ * alarm registers are used to set auxiliary alarm. Both alarm event and
+ * auxiliary alarm event can wake up system from deep sleep, but only alarm
+ * event can power up system from power down status.
+ */
+enum sprd_rtc_reg_types {
+ SPRD_RTC_TIME,
+ SPRD_RTC_ALARM,
+ SPRD_RTC_AUX_ALARM,
+};
+
+static int sprd_rtc_clear_alarm_ints(struct sprd_rtc *rtc)
+{
+ return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
+ SPRD_RTC_ALM_INT_MASK);
+}
+
+static int sprd_rtc_disable_ints(struct sprd_rtc *rtc)
+{
+ int ret;
+
+ ret = regmap_update_bits(rtc->regmap, rtc->base + SPRD_RTC_INT_EN,
+ SPRD_RTC_INT_MASK, 0);
+ if (ret)
+ return ret;
+
+ return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
+ SPRD_RTC_INT_MASK);
+}
+
+static int sprd_rtc_lock_alarm(struct sprd_rtc *rtc, bool lock)
+{
+ int ret;
+ u32 val;
+
+ ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_SPG_VALUE, &val);
+ if (ret)
+ return ret;
+
+ val &= ~(SPRD_RTC_ALMLOCK_MASK | SPRD_RTC_POWEROFF_ALM_FLAG);
+ if (lock)
+ val |= SPRD_RTC_ALM_LOCK;
+ else
+ val |= SPRD_RTC_ALM_UNLOCK | SPRD_RTC_POWEROFF_ALM_FLAG;
+
+ ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_SPG_UPD, val);
+ if (ret)
+ return ret;
+
+ /* wait until the SPG value is updated successfully */
+ ret = regmap_read_poll_timeout(rtc->regmap,
+ rtc->base + SPRD_RTC_INT_RAW_STS, val,
+ (val & SPRD_RTC_SPG_UPD_EN),
+ SPRD_RTC_POLL_DELAY_US,
+ SPRD_RTC_POLL_TIMEOUT);
+ if (ret) {
+ dev_err(rtc->dev, "failed to update SPG value:%d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int sprd_rtc_get_secs(struct sprd_rtc *rtc, enum sprd_rtc_reg_types type,
+ time64_t *secs)
+{
+ u32 sec_reg, min_reg, hour_reg, day_reg;
+ u32 val, sec, min, hour, day;
+ int ret;
+
+ switch (type) {
+ case SPRD_RTC_TIME:
+ sec_reg = SPRD_RTC_SEC_CNT_VALUE;
+ min_reg = SPRD_RTC_MIN_CNT_VALUE;
+ hour_reg = SPRD_RTC_HOUR_CNT_VALUE;
+ day_reg = SPRD_RTC_DAY_CNT_VALUE;
+ break;
+ case SPRD_RTC_ALARM:
+ sec_reg = SPRD_RTC_SEC_ALM_VALUE;
+ min_reg = SPRD_RTC_MIN_ALM_VALUE;
+ hour_reg = SPRD_RTC_HOUR_ALM_VALUE;
+ day_reg = SPRD_RTC_DAY_ALM_VALUE;
+ break;
+ case SPRD_RTC_AUX_ALARM:
+ sec_reg = SPRD_RTC_SEC_AUXALM_UPD;
+ min_reg = SPRD_RTC_MIN_AUXALM_UPD;
+ hour_reg = SPRD_RTC_HOUR_AUXALM_UPD;
+ day_reg = SPRD_RTC_DAY_AUXALM_UPD;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ret = regmap_read(rtc->regmap, rtc->base + sec_reg, &val);
+ if (ret)
+ return ret;
+
+ sec = val & SPRD_RTC_SEC_MASK;
+
+ ret = regmap_read(rtc->regmap, rtc->base + min_reg, &val);
+ if (ret)
+ return ret;
+
+ min = val & SPRD_RTC_MIN_MASK;
+
+ ret = regmap_read(rtc->regmap, rtc->base + hour_reg, &val);
+ if (ret)
+ return ret;
+
+ hour = val & SPRD_RTC_HOUR_MASK;
+
+ ret = regmap_read(rtc->regmap, rtc->base + day_reg, &val);
+ if (ret)
+ return ret;
+
+ day = val & SPRD_RTC_DAY_MASK;
+ *secs = (((time64_t)(day * 24) + hour) * 60 + min) * 60 + sec;
+ return 0;
+}
+
+static int sprd_rtc_set_secs(struct sprd_rtc *rtc, enum sprd_rtc_reg_types type,
+ time64_t secs)
+{
+ u32 sec_reg, min_reg, hour_reg, day_reg, sts_mask;
+ u32 sec, min, hour, day, val;
+ int ret, rem;
+
+ /* convert seconds to RTC time format */
+ day = div_s64_rem(secs, 86400, &rem);
+ hour = rem / 3600;
+ rem -= hour * 3600;
+ min = rem / 60;
+ sec = rem - min * 60;
+
+ switch (type) {
+ case SPRD_RTC_TIME:
+ sec_reg = SPRD_RTC_SEC_CNT_UPD;
+ min_reg = SPRD_RTC_MIN_CNT_UPD;
+ hour_reg = SPRD_RTC_HOUR_CNT_UPD;
+ day_reg = SPRD_RTC_DAY_CNT_UPD;
+ sts_mask = SPRD_RTC_TIME_INT_MASK;
+ break;
+ case SPRD_RTC_ALARM:
+ sec_reg = SPRD_RTC_SEC_ALM_UPD;
+ min_reg = SPRD_RTC_MIN_ALM_UPD;
+ hour_reg = SPRD_RTC_HOUR_ALM_UPD;
+ day_reg = SPRD_RTC_DAY_ALM_UPD;
+ sts_mask = SPRD_RTC_ALMTIME_INT_MASK;
+ break;
+ case SPRD_RTC_AUX_ALARM:
+ sec_reg = SPRD_RTC_SEC_AUXALM_UPD;
+ min_reg = SPRD_RTC_MIN_AUXALM_UPD;
+ hour_reg = SPRD_RTC_HOUR_AUXALM_UPD;
+ day_reg = SPRD_RTC_DAY_AUXALM_UPD;
+ sts_mask = 0;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ ret = regmap_write(rtc->regmap, rtc->base + sec_reg, sec);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(rtc->regmap, rtc->base + min_reg, min);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(rtc->regmap, rtc->base + hour_reg, hour);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(rtc->regmap, rtc->base + day_reg, day);
+ if (ret)
+ return ret;
+
+ if (type == SPRD_RTC_AUX_ALARM)
+ return 0;
+
+ /*
+ * Since the time and normal alarm registers are put in always-power-on
+ * region supplied by VDDRTC, then these registers changing time will
+ * be very long, about 125ms. Thus here we should wait until all
+ * values are updated successfully.
+ */
+ ret = regmap_read_poll_timeout(rtc->regmap,
+ rtc->base + SPRD_RTC_INT_RAW_STS, val,
+ ((val & sts_mask) == sts_mask),
+ SPRD_RTC_POLL_DELAY_US,
+ SPRD_RTC_POLL_TIMEOUT);
+ if (ret < 0) {
+ dev_err(rtc->dev, "set time/alarm values timeout\n");
+ return ret;
+ }
+
+ return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
+ sts_mask);
+}
+
+static int sprd_rtc_read_aux_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct sprd_rtc *rtc = dev_get_drvdata(dev);
+ time64_t secs;
+ u32 val;
+ int ret;
+
+ ret = sprd_rtc_get_secs(rtc, SPRD_RTC_AUX_ALARM, &secs);
+ if (ret)
+ return ret;
+
+ rtc_time64_to_tm(secs, &alrm->time);
+
+ ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_EN, &val);
+ if (ret)
+ return ret;
+
+ alrm->enabled = !!(val & SPRD_RTC_AUXALM_EN);
+
+ ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_RAW_STS, &val);
+ if (ret)
+ return ret;
+
+ alrm->pending = !!(val & SPRD_RTC_AUXALM_EN);
+ return 0;
+}
+
+static int sprd_rtc_set_aux_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct sprd_rtc *rtc = dev_get_drvdata(dev);
+ time64_t secs = rtc_tm_to_time64(&alrm->time);
+ int ret;
+
+ /* clear the auxiliary alarm interrupt status */
+ ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
+ SPRD_RTC_AUXALM_EN);
+ if (ret)
+ return ret;
+
+ ret = sprd_rtc_set_secs(rtc, SPRD_RTC_AUX_ALARM, secs);
+ if (ret)
+ return ret;
+
+ if (alrm->enabled) {
+ ret = regmap_update_bits(rtc->regmap,
+ rtc->base + SPRD_RTC_INT_EN,
+ SPRD_RTC_AUXALM_EN,
+ SPRD_RTC_AUXALM_EN);
+ } else {
+ ret = regmap_update_bits(rtc->regmap,
+ rtc->base + SPRD_RTC_INT_EN,
+ SPRD_RTC_AUXALM_EN, 0);
+ }
+
+ return ret;
+}
+
+static int sprd_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct sprd_rtc *rtc = dev_get_drvdata(dev);
+ time64_t secs;
+ int ret;
+
+ if (!rtc->valid) {
+ dev_warn(dev, "RTC values are invalid\n");
+ return -EINVAL;
+ }
+
+ ret = sprd_rtc_get_secs(rtc, SPRD_RTC_TIME, &secs);
+ if (ret)
+ return ret;
+
+ rtc_time64_to_tm(secs, tm);
+ return rtc_valid_tm(tm);
+}
+
+static int sprd_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct sprd_rtc *rtc = dev_get_drvdata(dev);
+ time64_t secs = rtc_tm_to_time64(tm);
+ u32 val;
+ int ret;
+
+ ret = sprd_rtc_set_secs(rtc, SPRD_RTC_TIME, secs);
+ if (ret)
+ return ret;
+
+ if (!rtc->valid) {
+ /*
+ * Set SPRD_RTC_POWER_RESET_FLAG to indicate now RTC has valid
+ * time values.
+ */
+ ret = regmap_update_bits(rtc->regmap,
+ rtc->base + SPRD_RTC_SPG_UPD,
+ SPRD_RTC_POWER_RESET_FLAG,
+ SPRD_RTC_POWER_RESET_FLAG);
+ if (ret)
+ return ret;
+
+ ret = regmap_read_poll_timeout(rtc->regmap,
+ rtc->base + SPRD_RTC_INT_RAW_STS,
+ val, (val & SPRD_RTC_SPG_UPD_EN),
+ SPRD_RTC_POLL_DELAY_US,
+ SPRD_RTC_POLL_TIMEOUT);
+ if (ret) {
+ dev_err(rtc->dev, "failed to update SPG value:%d\n",
+ ret);
+ return ret;
+ }
+
+ rtc->valid = true;
+ }
+
+ return 0;
+}
+
+static int sprd_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct sprd_rtc *rtc = dev_get_drvdata(dev);
+ time64_t secs;
+ int ret;
+ u32 val;
+
+ /*
+ * If aie_timer is enabled, we should get the normal alarm time.
+ * Otherwise we should get auxiliary alarm time.
+ */
+ if (rtc->rtc && rtc->rtc->aie_timer.enabled == 0)
+ return sprd_rtc_read_aux_alarm(dev, alrm);
+
+ ret = sprd_rtc_get_secs(rtc, SPRD_RTC_ALARM, &secs);
+ if (ret)
+ return ret;
+
+ rtc_time64_to_tm(secs, &alrm->time);
+
+ ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_EN, &val);
+ if (ret)
+ return ret;
+
+ alrm->enabled = !!(val & SPRD_RTC_ALARM_EN);
+
+ ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_RAW_STS, &val);
+ if (ret)
+ return ret;
+
+ alrm->pending = !!(val & SPRD_RTC_ALARM_EN);
+ return 0;
+}
+
+static int sprd_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+ struct sprd_rtc *rtc = dev_get_drvdata(dev);
+ time64_t secs = rtc_tm_to_time64(&alrm->time);
+ struct rtc_time aie_time =
+ rtc_ktime_to_tm(rtc->rtc->aie_timer.node.expires);
+ int ret;
+
+ /*
+ * We have 2 groups alarms: normal alarm and auxiliary alarm. Since
+ * both normal alarm event and auxiliary alarm event can wake up system
+ * from deep sleep, but only alarm event can power up system from power
+ * down status. Moreover we do not need to poll about 125ms when
+ * updating auxiliary alarm registers. Thus we usually set auxiliary
+ * alarm when wake up system from deep sleep, and for other scenarios,
+ * we should set normal alarm with polling status.
+ *
+ * So here we check if the alarm time is set by aie_timer, if yes, we
+ * should set normal alarm, if not, we should set auxiliary alarm which
+ * means it is just a wake event.
+ */
+ if (!rtc->rtc->aie_timer.enabled || rtc_tm_sub(&aie_time, &alrm->time))
+ return sprd_rtc_set_aux_alarm(dev, alrm);
+
+ /* clear the alarm interrupt status firstly */
+ ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR,
+ SPRD_RTC_ALARM_EN);
+ if (ret)
+ return ret;
+
+ ret = sprd_rtc_set_secs(rtc, SPRD_RTC_ALARM, secs);
+ if (ret)
+ return ret;
+
+ if (alrm->enabled) {
+ ret = regmap_update_bits(rtc->regmap,
+ rtc->base + SPRD_RTC_INT_EN,
+ SPRD_RTC_ALARM_EN,
+ SPRD_RTC_ALARM_EN);
+ if (ret)
+ return ret;
+
+ /* unlock the alarm to enable the alarm function. */
+ ret = sprd_rtc_lock_alarm(rtc, false);
+ } else {
+ regmap_update_bits(rtc->regmap,
+ rtc->base + SPRD_RTC_INT_EN,
+ SPRD_RTC_ALARM_EN, 0);
+
+ /*
+ * Lock the alarm function in case fake alarm event will power
+ * up systems.
+ */
+ ret = sprd_rtc_lock_alarm(rtc, true);
+ }
+
+ return ret;
+}
+
+static int sprd_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+ struct sprd_rtc *rtc = dev_get_drvdata(dev);
+ int ret;
+
+ if (enabled) {
+ ret = regmap_update_bits(rtc->regmap,
+ rtc->base + SPRD_RTC_INT_EN,
+ SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN,
+ SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN);
+ if (ret)
+ return ret;
+
+ ret = sprd_rtc_lock_alarm(rtc, false);
+ } else {
+ regmap_update_bits(rtc->regmap, rtc->base + SPRD_RTC_INT_EN,
+ SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN, 0);
+
+ ret = sprd_rtc_lock_alarm(rtc, true);
+ }
+
+ return ret;
+}
+
+static const struct rtc_class_ops sprd_rtc_ops = {
+ .read_time = sprd_rtc_read_time,
+ .set_time = sprd_rtc_set_time,
+ .read_alarm = sprd_rtc_read_alarm,
+ .set_alarm = sprd_rtc_set_alarm,
+ .alarm_irq_enable = sprd_rtc_alarm_irq_enable,
+};
+
+static irqreturn_t sprd_rtc_handler(int irq, void *dev_id)
+{
+ struct sprd_rtc *rtc = dev_id;
+ int ret;
+
+ ret = sprd_rtc_clear_alarm_ints(rtc);
+ if (ret)
+ return IRQ_RETVAL(ret);
+
+ rtc_update_irq(rtc->rtc, 1, RTC_AF | RTC_IRQF);
+ return IRQ_HANDLED;
+}
+
+static int sprd_rtc_check_power_down(struct sprd_rtc *rtc)
+{
+ u32 val;
+ int ret;
+
+ ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_SPG_VALUE, &val);
+ if (ret)
+ return ret;
+
+ /*
+ * If the SPRD_RTC_POWER_RESET_FLAG was not set, which means the RTC has
+ * been powered down, so the RTC time values are invalid.
+ */
+ rtc->valid = (val & SPRD_RTC_POWER_RESET_FLAG) ? true : false;
+ return 0;
+}
+
+static int sprd_rtc_probe(struct platform_device *pdev)
+{
+ struct device_node *node = pdev->dev.of_node;
+ struct sprd_rtc *rtc;
+ int ret;
+
+ rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
+ if (!rtc)
+ return -ENOMEM;
+
+ rtc->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+ if (!rtc->regmap)
+ return -ENODEV;
+
+ ret = of_property_read_u32(node, "reg", &rtc->base);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to get RTC base address\n");
+ return ret;
+ }
+
+ rtc->irq = platform_get_irq(pdev, 0);
+ if (rtc->irq < 0) {
+ dev_err(&pdev->dev, "failed to get RTC irq number\n");
+ return rtc->irq;
+ }
+
+ rtc->dev = &pdev->dev;
+ platform_set_drvdata(pdev, rtc);
+
+ /* clear all RTC interrupts and disable all RTC interrupts */
+ ret = sprd_rtc_disable_ints(rtc);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to disable RTC interrupts\n");
+ return ret;
+ }
+
+ /* check if RTC time values are valid */
+ ret = sprd_rtc_check_power_down(rtc);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to check RTC time values\n");
+ return ret;
+ }
+
+ ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
+ sprd_rtc_handler,
+ IRQF_ONESHOT | IRQF_EARLY_RESUME,
+ pdev->name, rtc);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to request RTC irq\n");
+ return ret;
+ }
+
+ rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
+ &sprd_rtc_ops, THIS_MODULE);
+ if (IS_ERR(rtc->rtc))
+ return PTR_ERR(rtc->rtc);
+
+ device_init_wakeup(&pdev->dev, 1);
+ return 0;
+}
+
+static int sprd_rtc_remove(struct platform_device *pdev)
+{
+ device_init_wakeup(&pdev->dev, 0);
+ return 0;
+}
+
+static const struct of_device_id sprd_rtc_of_match[] = {
+ { .compatible = "sprd,sc2731-rtc", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, sprd_rtc_of_match);
+
+static struct platform_driver sprd_rtc_driver = {
+ .driver = {
+ .name = "sprd-rtc",
+ .of_match_table = sprd_rtc_of_match,
+ },
+ .probe = sprd_rtc_probe,
+ .remove = sprd_rtc_remove,
+};
+module_platform_driver(sprd_rtc_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Spreadtrum RTC Device Driver");
+MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");
--
1.7.9.5
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  Last update: 2017-11-09 04:40    [W:0.081 / U:2.664 seconds]
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