drivers/rtc/rtc-pm8xxx.c: rework to support pm8941 rtc

Adds support for RTC device inside PM8941 PMIC.  The RTC in this PMIC
have two register spaces.  Thus the rtc-pm8xxx is slightly reworked to
reflect these differences.

The register set for different PMIC chips are selected on DT compatible
string base.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: simplify and fix locking in pm8xxx_rtc_set_time()]
Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Josh Cartwright <joshc@codeaurora.org>
Cc: Stanimir Varbanov <svarbanov@mm-sol.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 135 insertions, 89 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 94ae1798d48a..6dd12ddbabc6 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1320,7 +1320,7 @@ config RTC_DRV_LPC32XX
 
 config RTC_DRV_PM8XXX
         tristate "Qualcomm PMIC8XXX RTC"
-        depends on MFD_PM8XXX
+        depends on MFD_PM8XXX || MFD_SPMI_PMIC
         help
           If you say yes here you get support for the
           Qualcomm PMIC8XXX RTC.
diff --git a/drivers/rtc/rtc-pm8xxx.c b/drivers/rtc/rtc-pm8xxx.c
index 197699f358c7..5adcf111fc14 100644
--- a/drivers/rtc/rtc-pm8xxx.c
+++ b/drivers/rtc/rtc-pm8xxx.c
@@ -27,21 +27,36 @@
 
 /* RTC_CTRL register bit fields */
 #define PM8xxx_RTC_ENABLE               BIT(7)
-#define PM8xxx_RTC_ALARM_ENABLE         BIT(1)
 #define PM8xxx_RTC_ALARM_CLEAR          BIT(0)
 
 #define NUM_8_BIT_RTC_REGS              0x4
 
 /**
+ * struct pm8xxx_rtc_regs - describe RTC registers per PMIC versions
+ * @ctrl: base address of control register
+ * @write: base address of write register
+ * @read: base address of read register
+ * @alarm_ctrl: base address of alarm control register
+ * @alarm_ctrl2: base address of alarm control2 register
+ * @alarm_rw: base address of alarm read-write register
+ * @alarm_en: alarm enable mask
+ */
+struct pm8xxx_rtc_regs {
+        unsigned int ctrl;
+        unsigned int write;
+        unsigned int read;
+        unsigned int alarm_ctrl;
+        unsigned int alarm_ctrl2;
+        unsigned int alarm_rw;
+        unsigned int alarm_en;
+};
+
+/**
  * struct pm8xxx_rtc -  rtc driver internal structure
  * @rtc:                rtc device for this driver.
  * @regmap:             regmap used to access RTC registers
  * @allow_set_time:     indicates whether writing to the RTC is allowed
  * @rtc_alarm_irq:      rtc alarm irq number.
- * @rtc_base:           address of rtc control register.
- * @rtc_read_base:      base address of read registers.
- * @rtc_write_base:     base address of write registers.
- * @alarm_rw_base:      base address of alarm registers.
  * @ctrl_reg:           rtc control register.
  * @rtc_dev:            device structure.
  * @ctrl_reg_lock:      spinlock protecting access to ctrl_reg.
@@ -51,11 +66,7 @@ struct pm8xxx_rtc {
         struct regmap *regmap;
         bool allow_set_time;
         int rtc_alarm_irq;
-        int rtc_base;
-        int rtc_read_base;
-        int rtc_write_base;
-        int alarm_rw_base;
-        u8 ctrl_reg;
+        const struct pm8xxx_rtc_regs *regs;
         struct device *rtc_dev;
         spinlock_t ctrl_reg_lock;
 };
@@ -71,8 +82,10 @@ static int pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
         int rc, i;
         unsigned long secs, irq_flags;
-        u8 value[NUM_8_BIT_RTC_REGS], alarm_enabled = 0, ctrl_reg;
+        u8 value[NUM_8_BIT_RTC_REGS], alarm_enabled = 0;
+        unsigned int ctrl_reg;
         struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+        const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
 
         if (!rtc_dd->allow_set_time)
                 return -EACCES;
@@ -87,30 +100,30 @@ static int pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm)
         dev_dbg(dev, "Seconds value to be written to RTC = %lu\n", secs);
 
         spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
-        ctrl_reg = rtc_dd->ctrl_reg;
 
-        if (ctrl_reg & PM8xxx_RTC_ALARM_ENABLE) {
+        rc = regmap_read(rtc_dd->regmap, regs->ctrl, &ctrl_reg);
+        if (rc)
+                goto rtc_rw_fail;
+
+        if (ctrl_reg & regs->alarm_en) {
                 alarm_enabled = 1;
-                ctrl_reg &= ~PM8xxx_RTC_ALARM_ENABLE;
-                rc = regmap_write(rtc_dd->regmap, rtc_dd->rtc_base, ctrl_reg);
+                ctrl_reg &= ~regs->alarm_en;
+                rc = regmap_write(rtc_dd->regmap, regs->ctrl, ctrl_reg);
                 if (rc) {
                         dev_err(dev, "Write to RTC control register failed\n");
                         goto rtc_rw_fail;
                 }
-                rtc_dd->ctrl_reg = ctrl_reg;
-        } else {
-                spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
         }
 
         /* Write 0 to Byte[0] */
-        rc = regmap_write(rtc_dd->regmap, rtc_dd->rtc_write_base, 0);
+        rc = regmap_write(rtc_dd->regmap, regs->write, 0);
         if (rc) {
                 dev_err(dev, "Write to RTC write data register failed\n");
                 goto rtc_rw_fail;
         }
 
         /* Write Byte[1], Byte[2], Byte[3] */
-        rc = regmap_bulk_write(rtc_dd->regmap, rtc_dd->rtc_write_base + 1,
+        rc = regmap_bulk_write(rtc_dd->regmap, regs->write + 1,
                                &value[1], sizeof(value) - 1);
         if (rc) {
                 dev_err(dev, "Write to RTC write data register failed\n");
@@ -118,25 +131,23 @@ static int pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm)
         }
 
         /* Write Byte[0] */
-        rc = regmap_write(rtc_dd->regmap, rtc_dd->rtc_write_base, value[0]);
+        rc = regmap_write(rtc_dd->regmap, regs->write, value[0]);
         if (rc) {
                 dev_err(dev, "Write to RTC write data register failed\n");
                 goto rtc_rw_fail;
         }
 
         if (alarm_enabled) {
-                ctrl_reg |= PM8xxx_RTC_ALARM_ENABLE;
-                rc = regmap_write(rtc_dd->regmap, rtc_dd->rtc_base, ctrl_reg);
+                ctrl_reg |= regs->alarm_en;
+                rc = regmap_write(rtc_dd->regmap, regs->ctrl, ctrl_reg);
                 if (rc) {
                         dev_err(dev, "Write to RTC control register failed\n");
                         goto rtc_rw_fail;
                 }
-                rtc_dd->ctrl_reg = ctrl_reg;
         }
 
 rtc_rw_fail:
-        if (alarm_enabled)
-                spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+        spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
 
         return rc;
 }
@@ -148,9 +159,9 @@ static int pm8xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
         unsigned long secs;
         unsigned int reg;
         struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+        const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
 
-        rc = regmap_bulk_read(rtc_dd->regmap, rtc_dd->rtc_read_base,
-                              value, sizeof(value));
+        rc = regmap_bulk_read(rtc_dd->regmap, regs->read, value, sizeof(value));
         if (rc) {
                 dev_err(dev, "RTC read data register failed\n");
                 return rc;
@@ -160,14 +171,14 @@ static int pm8xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
          * Read the LSB again and check if there has been a carry over.
          * If there is, redo the read operation.
          */
-        rc = regmap_read(rtc_dd->regmap, rtc_dd->rtc_read_base, &reg);
+        rc = regmap_read(rtc_dd->regmap, regs->read, &reg);
         if (rc < 0) {
                 dev_err(dev, "RTC read data register failed\n");
                 return rc;
         }
 
         if (unlikely(reg < value[0])) {
-                rc = regmap_bulk_read(rtc_dd->regmap, rtc_dd->rtc_read_base,
+                rc = regmap_bulk_read(rtc_dd->regmap, regs->read,
                                       value, sizeof(value));
                 if (rc) {
                         dev_err(dev, "RTC read data register failed\n");
@@ -195,9 +206,11 @@ static int pm8xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
 static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 {
         int rc, i;
-        u8 value[NUM_8_BIT_RTC_REGS], ctrl_reg;
+        u8 value[NUM_8_BIT_RTC_REGS];
+        unsigned int ctrl_reg;
         unsigned long secs, irq_flags;
         struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+        const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
 
         rtc_tm_to_time(&alarm->time, &secs);
 
@@ -208,28 +221,28 @@ static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 
         spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
 
-        rc = regmap_bulk_write(rtc_dd->regmap, rtc_dd->alarm_rw_base, value,
+        rc = regmap_bulk_write(rtc_dd->regmap, regs->alarm_rw, value,
                                sizeof(value));
         if (rc) {
                 dev_err(dev, "Write to RTC ALARM register failed\n");
                 goto rtc_rw_fail;
         }
 
-        ctrl_reg = rtc_dd->ctrl_reg;
+        rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg);
+        if (rc)
+                goto rtc_rw_fail;
 
         if (alarm->enabled)
-                ctrl_reg |= PM8xxx_RTC_ALARM_ENABLE;
+                ctrl_reg |= regs->alarm_en;
         else
-                ctrl_reg &= ~PM8xxx_RTC_ALARM_ENABLE;
+                ctrl_reg &= ~regs->alarm_en;
 
-        rc = regmap_write(rtc_dd->regmap, rtc_dd->rtc_base, ctrl_reg);
+        rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg);
         if (rc) {
-                dev_err(dev, "Write to RTC control register failed\n");
+                dev_err(dev, "Write to RTC alarm control register failed\n");
                 goto rtc_rw_fail;
         }
 
-        rtc_dd->ctrl_reg = ctrl_reg;
-
         dev_dbg(dev, "Alarm Set for h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
                 alarm->time.tm_hour, alarm->time.tm_min,
                 alarm->time.tm_sec, alarm->time.tm_mday,
@@ -245,8 +258,9 @@ static int pm8xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
         u8 value[NUM_8_BIT_RTC_REGS];
         unsigned long secs;
         struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
+        const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
 
-        rc = regmap_bulk_read(rtc_dd->regmap, rtc_dd->alarm_rw_base, value,
+        rc = regmap_bulk_read(rtc_dd->regmap, regs->alarm_rw, value,
                               sizeof(value));
         if (rc) {
                 dev_err(dev, "RTC alarm time read failed\n");
@@ -276,25 +290,26 @@ static int pm8xxx_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
         int rc;
         unsigned long irq_flags;
         struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
-        u8 ctrl_reg;
+        const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
+        unsigned int ctrl_reg;
 
         spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
 
-        ctrl_reg = rtc_dd->ctrl_reg;
+        rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg);
+        if (rc)
+                goto rtc_rw_fail;
 
         if (enable)
-                ctrl_reg |= PM8xxx_RTC_ALARM_ENABLE;
+                ctrl_reg |= regs->alarm_en;
         else
-                ctrl_reg &= ~PM8xxx_RTC_ALARM_ENABLE;
+                ctrl_reg &= ~regs->alarm_en;
 
-        rc = regmap_write(rtc_dd->regmap, rtc_dd->rtc_base, ctrl_reg);
+        rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg);
         if (rc) {
                 dev_err(dev, "Write to RTC control register failed\n");
                 goto rtc_rw_fail;
         }
 
-        rtc_dd->ctrl_reg = ctrl_reg;
-
 rtc_rw_fail:
         spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
         return rc;
@@ -311,6 +326,7 @@ static const struct rtc_class_ops pm8xxx_rtc_ops = {
 static irqreturn_t pm8xxx_alarm_trigger(int irq, void *dev_id)
 {
         struct pm8xxx_rtc *rtc_dd = dev_id;
+        const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
         unsigned int ctrl_reg;
         int rc;
         unsigned long irq_flags;
@@ -320,48 +336,100 @@ static irqreturn_t pm8xxx_alarm_trigger(int irq, void *dev_id)
         spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
 
         /* Clear the alarm enable bit */
-        ctrl_reg = rtc_dd->ctrl_reg;
-        ctrl_reg &= ~PM8xxx_RTC_ALARM_ENABLE;
+        rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg);
+        if (rc) {
+                spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+                goto rtc_alarm_handled;
+        }
+
+        ctrl_reg &= ~regs->alarm_en;
 
-        rc = regmap_write(rtc_dd->regmap, rtc_dd->rtc_base, ctrl_reg);
+        rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg);
         if (rc) {
                 spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
                 dev_err(rtc_dd->rtc_dev,
-                        "Write to RTC control register failed\n");
+                        "Write to alarm control register failed\n");
                 goto rtc_alarm_handled;
         }
 
-        rtc_dd->ctrl_reg = ctrl_reg;
         spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
 
         /* Clear RTC alarm register */
-        rc = regmap_read(rtc_dd->regmap,
-                         rtc_dd->rtc_base + PM8XXX_ALARM_CTRL_OFFSET,
-                         &ctrl_reg);
+        rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl2, &ctrl_reg);
         if (rc) {
                 dev_err(rtc_dd->rtc_dev,
-                        "RTC Alarm control register read failed\n");
+                        "RTC Alarm control2 register read failed\n");
                 goto rtc_alarm_handled;
         }
 
-        ctrl_reg &= ~PM8xxx_RTC_ALARM_CLEAR;
-        rc = regmap_write(rtc_dd->regmap,
-                          rtc_dd->rtc_base + PM8XXX_ALARM_CTRL_OFFSET,
-                          ctrl_reg);
+        ctrl_reg |= PM8xxx_RTC_ALARM_CLEAR;
+        rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl2, ctrl_reg);
         if (rc)
                 dev_err(rtc_dd->rtc_dev,
-                        "Write to RTC Alarm control register failed\n");
+                        "Write to RTC Alarm control2 register failed\n");
 
 rtc_alarm_handled:
         return IRQ_HANDLED;
 }
 
+static int pm8xxx_rtc_enable(struct pm8xxx_rtc *rtc_dd)
+{
+        const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
+        unsigned int ctrl_reg;
+        int rc;
+
+        /* Check if the RTC is on, else turn it on */
+        rc = regmap_read(rtc_dd->regmap, regs->ctrl, &ctrl_reg);
+        if (rc)
+                return rc;
+
+        if (!(ctrl_reg & PM8xxx_RTC_ENABLE)) {
+                ctrl_reg |= PM8xxx_RTC_ENABLE;
+                rc = regmap_write(rtc_dd->regmap, regs->ctrl, ctrl_reg);
+                if (rc)
+                        return rc;
+        }
+
+        return 0;
+}
+
+static const struct pm8xxx_rtc_regs pm8921_regs = {
+        .ctrl           = 0x11d,
+        .write          = 0x11f,
+        .read           = 0x123,
+        .alarm_rw       = 0x127,
+        .alarm_ctrl     = 0x11d,
+        .alarm_ctrl2    = 0x11e,
+        .alarm_en       = BIT(1),
+};
+
+static const struct pm8xxx_rtc_regs pm8058_regs = {
+        .ctrl           = 0x1e8,
+        .write          = 0x1ea,
+        .read           = 0x1ee,
+        .alarm_rw       = 0x1f2,
+        .alarm_ctrl     = 0x1e8,
+        .alarm_ctrl2    = 0x1e9,
+        .alarm_en       = BIT(1),
+};
+
+static const struct pm8xxx_rtc_regs pm8941_regs = {
+        .ctrl           = 0x6046,
+        .write          = 0x6040,
+        .read           = 0x6048,
+        .alarm_rw       = 0x6140,
+        .alarm_ctrl     = 0x6146,
+        .alarm_ctrl2    = 0x6148,
+        .alarm_en       = BIT(7),
+};
+
 /*
  * Hardcoded RTC bases until IORESOURCE_REG mapping is figured out
  */
 static const struct of_device_id pm8xxx_id_table[] = {
-        { .compatible = "qcom,pm8921-rtc", .data = (void *) 0x11D },
-        { .compatible = "qcom,pm8058-rtc", .data = (void *) 0x1E8 },
+        { .compatible = "qcom,pm8921-rtc", .data = &pm8921_regs },
+        { .compatible = "qcom,pm8058-rtc", .data = &pm8058_regs },
+        { .compatible = "qcom,pm8941-rtc", .data = &pm8941_regs },
         { },
 };
 MODULE_DEVICE_TABLE(of, pm8xxx_id_table);
@@ -369,7 +437,6 @@ MODULE_DEVICE_TABLE(of, pm8xxx_id_table);
 static int pm8xxx_rtc_probe(struct platform_device *pdev)
 {
         int rc;
-        unsigned int ctrl_reg;
         struct pm8xxx_rtc *rtc_dd;
         const struct of_device_id *match;
 
@@ -399,33 +466,12 @@ static int pm8xxx_rtc_probe(struct platform_device *pdev)
         rtc_dd->allow_set_time = of_property_read_bool(pdev->dev.of_node,
                                                       "allow-set-time");
 
-        rtc_dd->rtc_base = (long) match->data;
-
-        /* Setup RTC register addresses */
-        rtc_dd->rtc_write_base = rtc_dd->rtc_base + PM8XXX_RTC_WRITE_OFFSET;
-        rtc_dd->rtc_read_base = rtc_dd->rtc_base + PM8XXX_RTC_READ_OFFSET;
-        rtc_dd->alarm_rw_base = rtc_dd->rtc_base + PM8XXX_ALARM_RW_OFFSET;
-
+        rtc_dd->regs = match->data;
         rtc_dd->rtc_dev = &pdev->dev;
 
-        /* Check if the RTC is on, else turn it on */
-        rc = regmap_read(rtc_dd->regmap, rtc_dd->rtc_base, &ctrl_reg);
-        if (rc) {
-                dev_err(&pdev->dev, "RTC control register read failed!\n");
+        rc = pm8xxx_rtc_enable(rtc_dd);
+        if (rc)
                 return rc;
-        }
-
-        if (!(ctrl_reg & PM8xxx_RTC_ENABLE)) {
-                ctrl_reg |= PM8xxx_RTC_ENABLE;
-                rc = regmap_write(rtc_dd->regmap, rtc_dd->rtc_base, ctrl_reg);
-                if (rc) {
-                        dev_err(&pdev->dev,
-                                "Write to RTC control register failed\n");
-                        return rc;
-                }
-        }
-
-        rtc_dd->ctrl_reg = ctrl_reg;
 
         platform_set_drvdata(pdev, rtc_dd);