diff options
author | Amelie Delaunay <amelie.delaunay@st.com> | 2017-07-06 11:47:45 +0300 |
---|---|---|
committer | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2017-07-06 23:52:54 +0300 |
commit | 9a6757eadc14f01385fd41fe3906dc22dcdb919e (patch) | |
tree | d9ba70e5ab396257a7d339c4feb2c7ad54183018 /drivers/rtc | |
parent | d2be279bcd8055ddfd92cc5f5d305eb3651e059b (diff) | |
download | linux-9a6757eadc14f01385fd41fe3906dc22dcdb919e.tar.xz |
rtc: stm32: add STM32H7 RTC support
This patch adds support for STM32H7 RTC. On STM32H7, the RTC bus interface
clock (APB clock) needs to be enabled.
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Diffstat (limited to 'drivers/rtc')
-rw-r--r-- | drivers/rtc/rtc-stm32.c | 82 |
1 files changed, 65 insertions, 17 deletions
diff --git a/drivers/rtc/rtc-stm32.c b/drivers/rtc/rtc-stm32.c index bd57eb1029e1..3a5c3d7d0c77 100644 --- a/drivers/rtc/rtc-stm32.c +++ b/drivers/rtc/rtc-stm32.c @@ -94,11 +94,17 @@ /* STM32_PWR_CR bit field */ #define PWR_CR_DBP BIT(8) +struct stm32_rtc_data { + bool has_pclk; +}; + struct stm32_rtc { struct rtc_device *rtc_dev; void __iomem *base; struct regmap *dbp; - struct clk *ck_rtc; + struct stm32_rtc_data *data; + struct clk *pclk; + struct clk *rtc_ck; int irq_alarm; }; @@ -122,9 +128,9 @@ static int stm32_rtc_enter_init_mode(struct stm32_rtc *rtc) writel_relaxed(isr, rtc->base + STM32_RTC_ISR); /* - * It takes around 2 ck_rtc clock cycles to enter in + * It takes around 2 rtc_ck clock cycles to enter in * initialization phase mode (and have INITF flag set). As - * slowest ck_rtc frequency may be 32kHz and highest should be + * 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( @@ -153,7 +159,7 @@ static int stm32_rtc_wait_sync(struct stm32_rtc *rtc) /* * Wait for RSF to be set to ensure the calendar registers are - * synchronised, it takes around 2 ck_rtc clock cycles + * synchronised, it takes around 2 rtc_ck clock cycles */ return readl_relaxed_poll_timeout_atomic(rtc->base + STM32_RTC_ISR, isr, @@ -456,7 +462,7 @@ static int stm32_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) /* * Poll Alarm write flag to be sure that Alarm update is allowed: it - * takes around 2 ck_rtc clock cycles + * takes around 2 rtc_ck clock cycles */ ret = readl_relaxed_poll_timeout_atomic(rtc->base + STM32_RTC_ISR, isr, @@ -490,8 +496,17 @@ static const struct rtc_class_ops stm32_rtc_ops = { .alarm_irq_enable = stm32_rtc_alarm_irq_enable, }; +static const struct stm32_rtc_data stm32_rtc_data = { + .has_pclk = false, +}; + +static const struct stm32_rtc_data stm32h7_rtc_data = { + .has_pclk = true, +}; + static const struct of_device_id stm32_rtc_of_match[] = { - { .compatible = "st,stm32-rtc" }, + { .compatible = "st,stm32-rtc", .data = &stm32_rtc_data }, + { .compatible = "st,stm32h7-rtc", .data = &stm32h7_rtc_data }, {} }; MODULE_DEVICE_TABLE(of, stm32_rtc_of_match); @@ -503,7 +518,7 @@ static int stm32_rtc_init(struct platform_device *pdev, unsigned int rate; int ret = 0; - rate = clk_get_rate(rtc->ck_rtc); + rate = clk_get_rate(rtc->rtc_ck); /* Find prediv_a and prediv_s to obtain the 1Hz calendar clock */ pred_a_max = STM32_RTC_PRER_PRED_A >> STM32_RTC_PRER_PRED_A_SHIFT; @@ -524,7 +539,7 @@ static int stm32_rtc_init(struct platform_device *pdev, pred_a = pred_a_max; pred_s = (rate / (pred_a + 1)) - 1; - dev_warn(&pdev->dev, "ck_rtc is %s\n", + dev_warn(&pdev->dev, "rtc_ck is %s\n", (rate < ((pred_a + 1) * (pred_s + 1))) ? "fast" : "slow"); } @@ -561,6 +576,7 @@ static int stm32_rtc_probe(struct platform_device *pdev) { struct stm32_rtc *rtc; struct resource *res; + const struct of_device_id *match; int ret; rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); @@ -579,15 +595,34 @@ static int stm32_rtc_probe(struct platform_device *pdev) return PTR_ERR(rtc->dbp); } - rtc->ck_rtc = devm_clk_get(&pdev->dev, NULL); - if (IS_ERR(rtc->ck_rtc)) { - dev_err(&pdev->dev, "no ck_rtc clock"); - return PTR_ERR(rtc->ck_rtc); + match = of_match_device(stm32_rtc_of_match, &pdev->dev); + rtc->data = (struct stm32_rtc_data *)match->data; + + if (!rtc->data->has_pclk) { + rtc->pclk = NULL; + 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); + } + 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 (rtc->data->has_pclk) { + ret = clk_prepare_enable(rtc->pclk); + if (ret) + return ret; } - ret = clk_prepare_enable(rtc->ck_rtc); + ret = clk_prepare_enable(rtc->rtc_ck); if (ret) - return ret; + goto err; regmap_update_bits(rtc->dbp, PWR_CR, PWR_CR_DBP, PWR_CR_DBP); @@ -595,7 +630,7 @@ static int stm32_rtc_probe(struct platform_device *pdev) * After a system reset, RTC_ISR.INITS flag can be read to check if * the calendar has been initalized or not. INITS flag is reset by a * power-on reset (no vbat, no power-supply). It is not reset if - * ck_rtc parent clock has changed (so RTC prescalers need to be + * rtc_ck parent clock has changed (so RTC prescalers need to be * changed). That's why we cannot rely on this flag to know if RTC * init has to be done. */ @@ -646,7 +681,9 @@ static int stm32_rtc_probe(struct platform_device *pdev) return 0; err: - clk_disable_unprepare(rtc->ck_rtc); + if (rtc->data->has_pclk) + clk_disable_unprepare(rtc->pclk); + clk_disable_unprepare(rtc->rtc_ck); regmap_update_bits(rtc->dbp, PWR_CR, PWR_CR_DBP, 0); @@ -667,7 +704,9 @@ static int stm32_rtc_remove(struct platform_device *pdev) writel_relaxed(cr, rtc->base + STM32_RTC_CR); stm32_rtc_wpr_lock(rtc); - clk_disable_unprepare(rtc->ck_rtc); + clk_disable_unprepare(rtc->rtc_ck); + if (rtc->data->has_pclk) + clk_disable_unprepare(rtc->pclk); /* Enable backup domain write protection */ regmap_update_bits(rtc->dbp, PWR_CR, PWR_CR_DBP, 0); @@ -682,6 +721,9 @@ static int stm32_rtc_suspend(struct device *dev) { struct stm32_rtc *rtc = dev_get_drvdata(dev); + if (rtc->data->has_pclk) + clk_disable_unprepare(rtc->pclk); + if (device_may_wakeup(dev)) return enable_irq_wake(rtc->irq_alarm); @@ -693,6 +735,12 @@ static int stm32_rtc_resume(struct device *dev) struct stm32_rtc *rtc = dev_get_drvdata(dev); int ret = 0; + if (rtc->data->has_pclk) { + ret = clk_prepare_enable(rtc->pclk); + if (ret) + return ret; + } + ret = stm32_rtc_wait_sync(rtc); if (ret < 0) return ret; |