diff options
Diffstat (limited to 'drivers/rtc/rtc-stm32.c')
-rw-r--r-- | drivers/rtc/rtc-stm32.c | 143 |
1 files changed, 87 insertions, 56 deletions
diff --git a/drivers/rtc/rtc-stm32.c b/drivers/rtc/rtc-stm32.c index 3d36e11cff80..76753c71d92e 100644 --- a/drivers/rtc/rtc-stm32.c +++ b/drivers/rtc/rtc-stm32.c @@ -6,11 +6,13 @@ #include <linux/bcd.h> #include <linux/clk.h> +#include <linux/errno.h> #include <linux/iopoll.h> #include <linux/ioport.h> #include <linux/mfd/syscon.h> #include <linux/module.h> -#include <linux/of_device.h> +#include <linux/of.h> +#include <linux/platform_device.h> #include <linux/pm_wakeirq.h> #include <linux/regmap.h> #include <linux/rtc.h> @@ -89,6 +91,9 @@ /* Max STM32 RTC register offset is 0x3FC */ #define UNDEF_REG 0xFFFF +/* STM32 RTC driver time helpers */ +#define SEC_PER_DAY (24 * 60 * 60) + struct stm32_rtc; struct stm32_rtc_registers { @@ -114,6 +119,7 @@ struct stm32_rtc_data { void (*clear_events)(struct stm32_rtc *rtc, unsigned int flags); bool has_pclk; bool need_dbp; + bool need_accuracy; }; struct stm32_rtc { @@ -158,10 +164,9 @@ static int stm32_rtc_enter_init_mode(struct stm32_rtc *rtc) * slowest rtc_ck frequency may be 32kHz and highest should be * 1MHz, we poll every 10 us with a timeout of 100ms. */ - return readl_relaxed_poll_timeout_atomic( - rtc->base + regs->isr, - isr, (isr & STM32_RTC_ISR_INITF), - 10, 100000); + return readl_relaxed_poll_timeout_atomic(rtc->base + regs->isr, isr, + (isr & STM32_RTC_ISR_INITF), + 10, 100000); } return 0; @@ -425,40 +430,42 @@ static int stm32_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) return 0; } -static int stm32_rtc_valid_alrm(struct stm32_rtc *rtc, struct rtc_time *tm) +static int stm32_rtc_valid_alrm(struct device *dev, 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); - - cur_day = (dr & STM32_RTC_DR_DATE) >> STM32_RTC_DR_DATE_SHIFT; - cur_mon = (dr & STM32_RTC_DR_MONTH) >> STM32_RTC_DR_MONTH_SHIFT; - cur_year = (dr & STM32_RTC_DR_YEAR) >> STM32_RTC_DR_YEAR_SHIFT; - cur_sec = (tr & STM32_RTC_TR_SEC) >> STM32_RTC_TR_SEC_SHIFT; - cur_min = (tr & STM32_RTC_TR_MIN) >> STM32_RTC_TR_MIN_SHIFT; - cur_hour = (tr & STM32_RTC_TR_HOUR) >> STM32_RTC_TR_HOUR_SHIFT; + static struct rtc_time now; + time64_t max_alarm_time64; + int max_day_forward; + int next_month; + int next_year; /* * Assuming current date is M-D-Y H:M:S. * RTC alarm can't be set on a specific month and year. * So the valid alarm range is: * M-D-Y H:M:S < alarm <= (M+1)-D-Y H:M:S - * with a specific case for December... */ - if ((((tm->tm_year > cur_year) && - (tm->tm_mon == 0x1) && (cur_mon == 0x12)) || - ((tm->tm_year == cur_year) && - (tm->tm_mon <= cur_mon + 1))) && - ((tm->tm_mday > cur_day) || - ((tm->tm_mday == cur_day) && - ((tm->tm_hour > cur_hour) || - ((tm->tm_hour == cur_hour) && (tm->tm_min > cur_min)) || - ((tm->tm_hour == cur_hour) && (tm->tm_min == cur_min) && - (tm->tm_sec >= cur_sec)))))) - return 0; + stm32_rtc_read_time(dev, &now); + + /* + * Find the next month and the year of the next month. + * Note: tm_mon and next_month are from 0 to 11 + */ + next_month = now.tm_mon + 1; + if (next_month == 12) { + next_month = 0; + next_year = now.tm_year + 1; + } else { + next_year = now.tm_year; + } - return -EINVAL; + /* Find the maximum limit of alarm in days. */ + max_day_forward = rtc_month_days(now.tm_mon, now.tm_year) + - now.tm_mday + + min(rtc_month_days(next_month, next_year), now.tm_mday); + + /* Convert to timestamp and compare the alarm time and its upper limit */ + max_alarm_time64 = rtc_tm_to_time64(&now) + max_day_forward * SEC_PER_DAY; + return rtc_tm_to_time64(tm) <= max_alarm_time64 ? 0 : -EINVAL; } static int stm32_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) @@ -469,17 +476,17 @@ static int stm32_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) unsigned int cr, isr, alrmar; int ret = 0; - tm2bcd(tm); - /* * RTC alarm can't be set on a specific date, unless this date is * up to the same day of month next month. */ - if (stm32_rtc_valid_alrm(rtc, tm) < 0) { + if (stm32_rtc_valid_alrm(dev, tm) < 0) { dev_err(dev, "Alarm can be set only on upcoming month.\n"); return -EINVAL; } + tm2bcd(tm); + alrmar = 0; /* tm_year and tm_mon are not used because not supported by RTC */ alrmar |= (tm->tm_mday << STM32_RTC_ALRMXR_DATE_SHIFT) & @@ -545,6 +552,7 @@ static void stm32_rtc_clear_events(struct stm32_rtc *rtc, static const struct stm32_rtc_data stm32_rtc_data = { .has_pclk = false, .need_dbp = true, + .need_accuracy = false, .regs = { .tr = 0x00, .dr = 0x04, @@ -566,6 +574,7 @@ static const struct stm32_rtc_data stm32_rtc_data = { static const struct stm32_rtc_data stm32h7_rtc_data = { .has_pclk = true, .need_dbp = true, + .need_accuracy = false, .regs = { .tr = 0x00, .dr = 0x04, @@ -596,6 +605,7 @@ static void stm32mp1_rtc_clear_events(struct stm32_rtc *rtc, static const struct stm32_rtc_data stm32mp1_data = { .has_pclk = true, .need_dbp = false, + .need_accuracy = true, .regs = { .tr = 0x00, .dr = 0x04, @@ -628,7 +638,7 @@ 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); @@ -636,18 +646,32 @@ static int stm32_rtc_init(struct platform_device *pdev, pred_a_max = STM32_RTC_PRER_PRED_A >> STM32_RTC_PRER_PRED_A_SHIFT; pred_s_max = STM32_RTC_PRER_PRED_S >> STM32_RTC_PRER_PRED_S_SHIFT; - for (pred_a = pred_a_max; pred_a + 1 > 0; pred_a--) { - pred_s = (rate / (pred_a + 1)) - 1; + if (rate > (pred_a_max + 1) * (pred_s_max + 1)) { + dev_err(&pdev->dev, "rtc_ck rate is too high: %dHz\n", rate); + return -EINVAL; + } + + if (rtc->data->need_accuracy) { + for (pred_a = 0; pred_a <= pred_a_max; pred_a++) { + pred_s = (rate / (pred_a + 1)) - 1; + + if (pred_s <= pred_s_max && ((pred_s + 1) * (pred_a + 1)) == rate) + break; + } + } else { + for (pred_a = pred_a_max; pred_a + 1 > 0; pred_a--) { + pred_s = (rate / (pred_a + 1)) - 1; - if (((pred_s + 1) * (pred_a + 1)) == rate) - break; + if (((pred_s + 1) * (pred_a + 1)) == rate) + break; + } } /* * Can't find a 1Hz, so give priority to RTC power consumption * by choosing the higher possible value for prediv_a */ - if ((pred_s > pred_s_max) || (pred_a > pred_a_max)) { + if (pred_s > pred_s_max || pred_a > pred_a_max) { pred_a = pred_a_max; pred_s = (rate / (pred_a + 1)) - 1; @@ -656,6 +680,20 @@ 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 +703,10 @@ 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); @@ -730,16 +765,13 @@ static int stm32_rtc_probe(struct platform_device *pdev) rtc->rtc_ck = devm_clk_get(&pdev->dev, NULL); } else { rtc->pclk = devm_clk_get(&pdev->dev, "pclk"); - if (IS_ERR(rtc->pclk)) { - dev_err(&pdev->dev, "no pclk clock"); - return PTR_ERR(rtc->pclk); - } + if (IS_ERR(rtc->pclk)) + return dev_err_probe(&pdev->dev, PTR_ERR(rtc->pclk), "no pclk clock"); + rtc->rtc_ck = devm_clk_get(&pdev->dev, "rtc_ck"); } - if (IS_ERR(rtc->rtc_ck)) { - dev_err(&pdev->dev, "no rtc_ck clock"); - return PTR_ERR(rtc->rtc_ck); - } + if (IS_ERR(rtc->rtc_ck)) + return dev_err_probe(&pdev->dev, PTR_ERR(rtc->rtc_ck), "no rtc_ck clock"); if (rtc->data->has_pclk) { ret = clk_prepare_enable(rtc->pclk); @@ -859,7 +891,6 @@ static void stm32_rtc_remove(struct platform_device *pdev) device_init_wakeup(&pdev->dev, false); } -#ifdef CONFIG_PM_SLEEP static int stm32_rtc_suspend(struct device *dev) { struct stm32_rtc *rtc = dev_get_drvdata(dev); @@ -890,10 +921,10 @@ static int stm32_rtc_resume(struct device *dev) return ret; } -#endif -static SIMPLE_DEV_PM_OPS(stm32_rtc_pm_ops, - stm32_rtc_suspend, stm32_rtc_resume); +static const struct dev_pm_ops stm32_rtc_pm_ops = { + NOIRQ_SYSTEM_SLEEP_PM_OPS(stm32_rtc_suspend, stm32_rtc_resume) +}; static struct platform_driver stm32_rtc_driver = { .probe = stm32_rtc_probe, |