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rtc: pm8xxx: Fix issue in RTC write path

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[ Upstream commit 83220bf38b77a830f8e62ab1a0d0408304f9b966 ]

In order to set time in rtc, need to disable
rtc hw before writing into rtc registers.

Also fixes disabling of alarm while setting
rtc time.

Signed-off-by: Mohit Aggarwal <maggarwa@codeaurora.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mohit Aggarwal 2020-04-21 13:40:07 +01:00 committed by Greg Kroah-Hartman
parent d131045273
commit b0a7e39e8a
1 changed files with 39 additions and 12 deletions
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51
drivers/rtc/rtc-pm8xxx.c
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@ -74,16 +74,18 @@ struct pm8xxx_rtc {
/*
* Steps to write the RTC registers.
* 1. Disable alarm if enabled.
* 2. Write 0x00 to LSB.
* 3. Write Byte[1], Byte[2], Byte[3] then Byte[0].
* 4. Enable alarm if disabled in step 1.
* 2. Disable rtc if enabled.
* 3. Write 0x00 to LSB.
* 4. Write Byte[1], Byte[2], Byte[3] then Byte[0].
* 5. Enable rtc if disabled in step 2.
* 6. Enable alarm if disabled in step 1.
*/
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;
unsigned int ctrl_reg;
u8 value[NUM_8_BIT_RTC_REGS], alarm_enabled = 0, rtc_disabled = 0;
unsigned int ctrl_reg, rtc_ctrl_reg;
struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
@ -92,23 +94,38 @@ static int pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm)
rtc_tm_to_time(tm, &secs);
dev_dbg(dev, "Seconds value to be written to RTC = %lu\n", secs);
for (i = 0; i < NUM_8_BIT_RTC_REGS; i++) {
value[i] = secs & 0xFF;
secs >>= 8;
}
dev_dbg(dev, "Seconds value to be written to RTC = %lu\n", secs);
spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
rc = regmap_read(rtc_dd->regmap, regs->ctrl, &ctrl_reg);
rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg);
if (rc)
goto rtc_rw_fail;
if (ctrl_reg & regs->alarm_en) {
alarm_enabled = 1;
ctrl_reg &= ~regs->alarm_en;
rc = regmap_write(rtc_dd->regmap, regs->ctrl, ctrl_reg);
rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg);
if (rc) {
dev_err(dev, "Write to RTC Alarm control register failed\n");
goto rtc_rw_fail;
}
}
/* Disable RTC H/w before writing on RTC register */
rc = regmap_read(rtc_dd->regmap, regs->ctrl, &rtc_ctrl_reg);
if (rc)
goto rtc_rw_fail;
if (rtc_ctrl_reg & PM8xxx_RTC_ENABLE) {
rtc_disabled = 1;
rtc_ctrl_reg &= ~PM8xxx_RTC_ENABLE;
rc = regmap_write(rtc_dd->regmap, regs->ctrl, rtc_ctrl_reg);
if (rc) {
dev_err(dev, "Write to RTC control register failed\n");
goto rtc_rw_fail;
@ -137,15 +154,25 @@ static int pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm)
goto rtc_rw_fail;
}
if (alarm_enabled) {
ctrl_reg |= regs->alarm_en;
rc = regmap_write(rtc_dd->regmap, regs->ctrl, ctrl_reg);
/* Enable RTC H/w after writing on RTC register */
if (rtc_disabled) {
rtc_ctrl_reg |= PM8xxx_RTC_ENABLE;
rc = regmap_write(rtc_dd->regmap, regs->ctrl, rtc_ctrl_reg);
if (rc) {
dev_err(dev, "Write to RTC control register failed\n");
goto rtc_rw_fail;
}
}
if (alarm_enabled) {
ctrl_reg |= regs->alarm_en;
rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg);
if (rc) {
dev_err(dev, "Write to RTC Alarm control register failed\n");
goto rtc_rw_fail;
}
}
rtc_rw_fail:
spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);