From 8d273f33fd090a2c270c67b6ac7fa03f5a7eee3f Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Thu, 2 Feb 2023 16:54:30 +0100 Subject: rtc: pm8xxx: drop bogus locking Since commit c8d523a4b053 ("drivers/rtc/rtc-pm8xxx.c: rework to support pm8941 rtc") which removed the shadow control register there is no need for a driver lock. Specifically, the rtc ops are serialised by rtc core and the interrupt handler only unconditionally disables the alarm using the alarm_ctrl register. Note that since only the alarm enable bit of alarm_ctrl is used after enabling the RTC at probe, the locking was not needed when doing open coded read-modify-write cycles either. Signed-off-by: Johan Hovold Reviewed-by: David Collins Link: https://lore.kernel.org/r/20230202155448.6715-5-johan+linaro@kernel.org Signed-off-by: Alexandre Belloni --- drivers/rtc/rtc-pm8xxx.c | 67 +++++++++++++++--------------------------------- 1 file changed, 21 insertions(+), 46 deletions(-) (limited to 'drivers/rtc') diff --git a/drivers/rtc/rtc-pm8xxx.c b/drivers/rtc/rtc-pm8xxx.c index 8c2847ac64f4..053a04f74a91 100644 --- a/drivers/rtc/rtc-pm8xxx.c +++ b/drivers/rtc/rtc-pm8xxx.c @@ -53,7 +53,6 @@ struct pm8xxx_rtc_regs { * @rtc_alarm_irq: rtc alarm irq number. * @regs: rtc registers description. * @rtc_dev: device structure. - * @ctrl_reg_lock: spinlock protecting access to ctrl_reg. */ struct pm8xxx_rtc { struct rtc_device *rtc; @@ -62,7 +61,6 @@ struct pm8xxx_rtc { int rtc_alarm_irq; const struct pm8xxx_rtc_regs *regs; struct device *rtc_dev; - spinlock_t ctrl_reg_lock; }; /* @@ -77,11 +75,11 @@ struct pm8xxx_rtc { static int pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm) { int rc, i; - unsigned long secs, irq_flags; struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; u8 value[NUM_8_BIT_RTC_REGS]; bool alarm_enabled; + unsigned long secs; if (!rtc_dd->allow_set_time) return -ENODEV; @@ -95,51 +93,46 @@ static int pm8xxx_rtc_set_time(struct device *dev, struct rtc_time *tm) secs >>= 8; } - spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags); - rc = regmap_update_bits_check(rtc_dd->regmap, regs->alarm_ctrl, regs->alarm_en, 0, &alarm_enabled); if (rc) - goto rtc_rw_fail; + return rc; /* Disable RTC H/w before writing on RTC register */ rc = regmap_update_bits(rtc_dd->regmap, regs->ctrl, PM8xxx_RTC_ENABLE, 0); if (rc) - goto rtc_rw_fail; + return rc; /* Write 0 to Byte[0] */ rc = regmap_write(rtc_dd->regmap, regs->write, 0); if (rc) - goto rtc_rw_fail; + return rc; /* Write Byte[1], Byte[2], Byte[3] */ rc = regmap_bulk_write(rtc_dd->regmap, regs->write + 1, &value[1], sizeof(value) - 1); if (rc) - goto rtc_rw_fail; + return rc; /* Write Byte[0] */ rc = regmap_write(rtc_dd->regmap, regs->write, value[0]); if (rc) - goto rtc_rw_fail; + return rc; /* Enable RTC H/w after writing on RTC register */ rc = regmap_update_bits(rtc_dd->regmap, regs->ctrl, PM8xxx_RTC_ENABLE, PM8xxx_RTC_ENABLE); if (rc) - goto rtc_rw_fail; + return rc; if (alarm_enabled) { rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl, regs->alarm_en, regs->alarm_en); if (rc) - goto rtc_rw_fail; + return rc; } -rtc_rw_fail: - spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags); - - return rc; + return 0; } static int pm8xxx_rtc_read_time(struct device *dev, struct rtc_time *tm) @@ -184,9 +177,9 @@ static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) { int rc, i; u8 value[NUM_8_BIT_RTC_REGS]; - unsigned long secs, irq_flags; struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev); const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; + unsigned long secs; secs = rtc_tm_to_time64(&alarm->time); @@ -200,25 +193,22 @@ static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) if (rc) return rc; - spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags); - rc = regmap_bulk_write(rtc_dd->regmap, regs->alarm_rw, value, sizeof(value)); if (rc) - goto rtc_rw_fail; + return rc; if (alarm->enabled) { rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl, regs->alarm_en, regs->alarm_en); if (rc) - goto rtc_rw_fail; + return rc; } dev_dbg(dev, "Alarm Set for h:m:s=%ptRt, y-m-d=%ptRdr\n", &alarm->time, &alarm->time); -rtc_rw_fail: - spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags); - return rc; + + return 0; } static int pm8xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) @@ -255,14 +245,11 @@ static int pm8xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 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); const struct pm8xxx_rtc_regs *regs = rtc_dd->regs; u8 value[NUM_8_BIT_RTC_REGS] = {0}; unsigned int val; - spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags); - if (enable) val = regs->alarm_en; else @@ -271,19 +258,17 @@ static int pm8xxx_rtc_alarm_irq_enable(struct device *dev, unsigned int enable) rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl, regs->alarm_en, val); if (rc) - goto rtc_rw_fail; + return rc; /* Clear Alarm register */ if (!enable) { rc = regmap_bulk_write(rtc_dd->regmap, regs->alarm_rw, value, sizeof(value)); if (rc) - goto rtc_rw_fail; + return rc; } -rtc_rw_fail: - spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags); - return rc; + return 0; } static const struct rtc_class_ops pm8xxx_rtc_ops = { @@ -302,25 +287,18 @@ static irqreturn_t pm8xxx_alarm_trigger(int irq, void *dev_id) rtc_update_irq(rtc_dd->rtc, 1, RTC_IRQF | RTC_AF); - spin_lock(&rtc_dd->ctrl_reg_lock); - /* Clear the alarm enable bit */ rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl, regs->alarm_en, 0); - if (rc) { - spin_unlock(&rtc_dd->ctrl_reg_lock); - goto rtc_alarm_handled; - } - - spin_unlock(&rtc_dd->ctrl_reg_lock); + if (rc) + goto out; /* Clear RTC alarm register */ rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl2, PM8xxx_RTC_ALARM_CLEAR, 0); if (rc) - goto rtc_alarm_handled; - -rtc_alarm_handled: + goto out; +out: return IRQ_HANDLED; } @@ -398,9 +376,6 @@ static int pm8xxx_rtc_probe(struct platform_device *pdev) if (rtc_dd == NULL) return -ENOMEM; - /* Initialise spinlock to protect RTC control register */ - spin_lock_init(&rtc_dd->ctrl_reg_lock); - rtc_dd->regmap = dev_get_regmap(pdev->dev.parent, NULL); if (!rtc_dd->regmap) { dev_err(&pdev->dev, "Parent regmap unavailable.\n"); -- cgit v1.2.3