From b0a7e39e8a53f474342e727e1edbdb4bd0952f4f Mon Sep 17 00:00:00 2001 From: Mohit Aggarwal Date: Tue, 21 Apr 2020 13:40:07 +0100 Subject: rtc: pm8xxx: Fix issue in RTC write path [ 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 Signed-off-by: Alexandre Belloni Signed-off-by: Lee Jones Signed-off-by: Greg Kroah-Hartman --- drivers/rtc/rtc-pm8xxx.c | 49 +++++++++++++++++++++++++++++++++++++----------- 1 file changed, 38 insertions(+), 11 deletions(-) diff --git a/drivers/rtc/rtc-pm8xxx.c b/drivers/rtc/rtc-pm8xxx.c index a1b4b0ed1f19..3b619b7b2c53 100644 --- a/drivers/rtc/rtc-pm8xxx.c +++ b/drivers/rtc/rtc-pm8xxx.c @@ -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; @@ -137,11 +154,21 @@ static int pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm) goto rtc_rw_fail; } + /* 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->ctrl, 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; } } -- cgit v1.2.3