This series implements some bug fixes for theses issues:
- typo issues
- register read sequence issue
- irq during pm callbacks issue
This series implements also some improvements:
- don't switch to INIT mode uselessly
- improve error printing during probe
- improve rtc precision on stm32mp1
Antonio Borneo (2):
rtc: stm32: use the proper register sequence to read date/time
rtc: stm32: don't stop time counter if not needed
Christophe Guibout (1):
rtc: stm32: improve rtc precision
Gabriel Fernandez (1):
rtc: stm32: change PM callbacks to "_noirq()"
Valentin Caron (3):
rtc: stm32: don't print an error on probe deferral
rtc: stm32: fix unnecessary parentheses
rtc: stm32: fix issues of stm32_rtc_valid_alrm function
drivers/rtc/rtc-stm32.c | 138 +++++++++++++++++++++++++---------------
1 file changed, 85 insertions(+), 53 deletions(-)
--
2.25.1
From: Antonio Borneo <[email protected]>
RTC counters are stopped when INIT bit in ISR register is set and
start counting from the (eventual) new value when INIT is reset.
In stm32_rtc_init(), called during probe, the INIT bit is set to
program the prescaler and the 24h mode. This halts the RTC counter
at each probe tentative causing the RTC time to loose from 0.3s to
0.8s at each kernel boot.
If the RTC is battery powered, both prescaler value and 24h mode
are kept during power cycle and there is no need to program them
again.
Check if the desired prescaler value and the 24h mode are already
programmed, then skip reprogramming them to avoid halting the time
counter.
Signed-off-by: Antonio Borneo <[email protected]>
Signed-off-by: Valentin Caron <[email protected]>
---
drivers/rtc/rtc-stm32.c | 23 +++++++++++++++++------
1 file changed, 17 insertions(+), 6 deletions(-)
diff --git a/drivers/rtc/rtc-stm32.c b/drivers/rtc/rtc-stm32.c
index abb77ad774a1..bd7a59a07537 100644
--- a/drivers/rtc/rtc-stm32.c
+++ b/drivers/rtc/rtc-stm32.c
@@ -628,7 +628,7 @@ static int stm32_rtc_init(struct platform_device *pdev,
const struct stm32_rtc_registers *regs = &rtc->data->regs;
unsigned int prer, pred_a, pred_s, pred_a_max, pred_s_max, cr;
unsigned int rate;
- int ret = 0;
+ int ret;
rate = clk_get_rate(rtc->rtc_ck);
@@ -656,6 +656,20 @@ static int stm32_rtc_init(struct platform_device *pdev,
"fast" : "slow");
}
+ cr = readl_relaxed(rtc->base + regs->cr);
+
+ prer = readl_relaxed(rtc->base + regs->prer);
+ prer &= STM32_RTC_PRER_PRED_S | STM32_RTC_PRER_PRED_A;
+
+ pred_s = (pred_s << STM32_RTC_PRER_PRED_S_SHIFT) &
+ STM32_RTC_PRER_PRED_S;
+ pred_a = (pred_a << STM32_RTC_PRER_PRED_A_SHIFT) &
+ STM32_RTC_PRER_PRED_A;
+
+ /* quit if there is nothing to initialize */
+ if ((cr & STM32_RTC_CR_FMT) == 0 && prer == (pred_s | pred_a))
+ return 0;
+
stm32_rtc_wpr_unlock(rtc);
ret = stm32_rtc_enter_init_mode(rtc);
@@ -665,13 +679,10 @@ static int stm32_rtc_init(struct platform_device *pdev,
goto end;
}
- prer = (pred_s << STM32_RTC_PRER_PRED_S_SHIFT) & STM32_RTC_PRER_PRED_S;
- writel_relaxed(prer, rtc->base + regs->prer);
- prer |= (pred_a << STM32_RTC_PRER_PRED_A_SHIFT) & STM32_RTC_PRER_PRED_A;
- writel_relaxed(prer, rtc->base + regs->prer);
+ writel_relaxed(pred_s, rtc->base + regs->prer);
+ writel_relaxed(pred_a | pred_s, rtc->base + regs->prer);
/* Force 24h time format */
- cr = readl_relaxed(rtc->base + regs->cr);
cr &= ~STM32_RTC_CR_FMT;
writel_relaxed(cr, rtc->base + regs->cr);
--
2.25.1
From: Antonio Borneo <[email protected]>
Date and time are read from two separate RTC registers.
To ensure consistency between the two registers, reading the time
register locks the values in the shadow date register until the
date register is read.
Thus, the whole date/time read requires reading the time register
first, followed by reading the date register.
If the reads are done in reversed order, the shadow date register
will remain locked until a future read operation. The future read
will read the former date value that could be already invalid.
Fix the read order of date/time registers in stm32_rtc_valid_alrm()
Signed-off-by: Antonio Borneo <[email protected]>
Signed-off-by: Valentin Caron <[email protected]>
---
drivers/rtc/rtc-stm32.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/rtc/rtc-stm32.c b/drivers/rtc/rtc-stm32.c
index 3d36e11cff80..abb77ad774a1 100644
--- a/drivers/rtc/rtc-stm32.c
+++ b/drivers/rtc/rtc-stm32.c
@@ -429,8 +429,8 @@ static int stm32_rtc_valid_alrm(struct stm32_rtc *rtc, struct rtc_time *tm)
{
const struct stm32_rtc_registers *regs = &rtc->data->regs;
int cur_day, cur_mon, cur_year, cur_hour, cur_min, cur_sec;
- unsigned int dr = readl_relaxed(rtc->base + regs->dr);
unsigned int tr = readl_relaxed(rtc->base + regs->tr);
+ unsigned int dr = readl_relaxed(rtc->base + regs->dr);
cur_day = (dr & STM32_RTC_DR_DATE) >> STM32_RTC_DR_DATE_SHIFT;
cur_mon = (dr & STM32_RTC_DR_MONTH) >> STM32_RTC_DR_MONTH_SHIFT;
--
2.25.1