From mboxrd@z Thu Jan 1 00:00:00 1970 From: amelie.delaunay@st.com (Amelie DELAUNAY) Date: Mon, 9 Jan 2017 17:46:52 +0100 Subject: [PATCHv3 3/8] rtc: add STM32 RTC driver In-Reply-To: <20170105173301.GA27341@linaro.org> References: <1483623809-29937-1-git-send-email-amelie.delaunay@st.com> <1483623809-29937-4-git-send-email-amelie.delaunay@st.com> <20170105173301.GA27341@linaro.org> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, Thanks for reviewing! Alexandre, could you please review this v3 and say when you plan to take this driver in the cycle ? Thanks, Amelie On 01/05/2017 06:33 PM, Mathieu Poirier wrote: > On Thu, Jan 05, 2017 at 02:43:24PM +0100, Amelie Delaunay wrote: >> This patch adds support for the STM32 RTC. >> >> Signed-off-by: Amelie Delaunay >> --- >> drivers/rtc/Kconfig | 11 + >> drivers/rtc/Makefile | 1 + >> drivers/rtc/rtc-stm32.c | 776 ++++++++++++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 788 insertions(+) >> create mode 100644 drivers/rtc/rtc-stm32.c >> >> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig >> index e859d14..11eb28a 100644 >> --- a/drivers/rtc/Kconfig >> +++ b/drivers/rtc/Kconfig >> @@ -1706,6 +1706,17 @@ config RTC_DRV_PIC32 >> This driver can also be built as a module. If so, the module >> will be called rtc-pic32 >> >> +config RTC_DRV_STM32 >> + tristate "STM32 RTC" >> + select REGMAP_MMIO >> + depends on ARCH_STM32 || COMPILE_TEST >> + help >> + If you say yes here you get support for the STM32 On-Chip >> + Real Time Clock. >> + >> + This driver can also be built as a module, if so, the module >> + will be called "rtc-stm32". >> + >> comment "HID Sensor RTC drivers" >> >> config RTC_DRV_HID_SENSOR_TIME >> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile >> index 1ac694a..87bd9cc 100644 >> --- a/drivers/rtc/Makefile >> +++ b/drivers/rtc/Makefile >> @@ -144,6 +144,7 @@ obj-$(CONFIG_RTC_DRV_SNVS) += rtc-snvs.o >> obj-$(CONFIG_RTC_DRV_SPEAR) += rtc-spear.o >> obj-$(CONFIG_RTC_DRV_STARFIRE) += rtc-starfire.o >> obj-$(CONFIG_RTC_DRV_STK17TA8) += rtc-stk17ta8.o >> +obj-$(CONFIG_RTC_DRV_STM32) += rtc-stm32.o >> obj-$(CONFIG_RTC_DRV_STMP) += rtc-stmp3xxx.o >> obj-$(CONFIG_RTC_DRV_ST_LPC) += rtc-st-lpc.o >> obj-$(CONFIG_RTC_DRV_SUN4V) += rtc-sun4v.o >> diff --git a/drivers/rtc/rtc-stm32.c b/drivers/rtc/rtc-stm32.c >> new file mode 100644 >> index 0000000..fdd3a31 >> --- /dev/null >> +++ b/drivers/rtc/rtc-stm32.c >> @@ -0,0 +1,776 @@ >> +/* >> + * Copyright (C) Amelie Delaunay 2016 >> + * Author: Amelie Delaunay >> + * License terms: GNU General Public License (GPL), version 2 >> + */ >> + >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> + >> +#define DRIVER_NAME "stm32_rtc" >> + >> +/* STM32 RTC registers */ >> +#define STM32_RTC_TR 0x00 >> +#define STM32_RTC_DR 0x04 >> +#define STM32_RTC_CR 0x08 >> +#define STM32_RTC_ISR 0x0C >> +#define STM32_RTC_PRER 0x10 >> +#define STM32_RTC_ALRMAR 0x1C >> +#define STM32_RTC_WPR 0x24 >> + >> +/* STM32_RTC_TR bit fields */ >> +#define STM32_RTC_TR_SEC_SHIFT 0 >> +#define STM32_RTC_TR_SEC GENMASK(6, 0) >> +#define STM32_RTC_TR_MIN_SHIFT 8 >> +#define STM32_RTC_TR_MIN GENMASK(14, 8) >> +#define STM32_RTC_TR_HOUR_SHIFT 16 >> +#define STM32_RTC_TR_HOUR GENMASK(21, 16) >> + >> +/* STM32_RTC_DR bit fields */ >> +#define STM32_RTC_DR_DATE_SHIFT 0 >> +#define STM32_RTC_DR_DATE GENMASK(5, 0) >> +#define STM32_RTC_DR_MONTH_SHIFT 8 >> +#define STM32_RTC_DR_MONTH GENMASK(12, 8) >> +#define STM32_RTC_DR_WDAY_SHIFT 13 >> +#define STM32_RTC_DR_WDAY GENMASK(15, 13) >> +#define STM32_RTC_DR_YEAR_SHIFT 16 >> +#define STM32_RTC_DR_YEAR GENMASK(23, 16) >> + >> +/* STM32_RTC_CR bit fields */ >> +#define STM32_RTC_CR_FMT BIT(6) >> +#define STM32_RTC_CR_ALRAE BIT(8) >> +#define STM32_RTC_CR_ALRAIE BIT(12) >> + >> +/* STM32_RTC_ISR bit fields */ >> +#define STM32_RTC_ISR_ALRAWF BIT(0) >> +#define STM32_RTC_ISR_INITS BIT(4) >> +#define STM32_RTC_ISR_RSF BIT(5) >> +#define STM32_RTC_ISR_INITF BIT(6) >> +#define STM32_RTC_ISR_INIT BIT(7) >> +#define STM32_RTC_ISR_ALRAF BIT(8) >> + >> +/* STM32_RTC_PRER bit fields */ >> +#define STM32_RTC_PRER_PRED_S_SHIFT 0 >> +#define STM32_RTC_PRER_PRED_S GENMASK(14, 0) >> +#define STM32_RTC_PRER_PRED_A_SHIFT 16 >> +#define STM32_RTC_PRER_PRED_A GENMASK(22, 16) >> + >> +/* STM32_RTC_ALRMAR and STM32_RTC_ALRMBR bit fields */ >> +#define STM32_RTC_ALRMXR_SEC_SHIFT 0 >> +#define STM32_RTC_ALRMXR_SEC GENMASK(6, 0) >> +#define STM32_RTC_ALRMXR_SEC_MASK BIT(7) >> +#define STM32_RTC_ALRMXR_MIN_SHIFT 8 >> +#define STM32_RTC_ALRMXR_MIN GENMASK(14, 8) >> +#define STM32_RTC_ALRMXR_MIN_MASK BIT(15) >> +#define STM32_RTC_ALRMXR_HOUR_SHIFT 16 >> +#define STM32_RTC_ALRMXR_HOUR GENMASK(21, 16) >> +#define STM32_RTC_ALRMXR_PM BIT(22) >> +#define STM32_RTC_ALRMXR_HOUR_MASK BIT(23) >> +#define STM32_RTC_ALRMXR_DATE_SHIFT 24 >> +#define STM32_RTC_ALRMXR_DATE GENMASK(29, 24) >> +#define STM32_RTC_ALRMXR_WDSEL BIT(30) >> +#define STM32_RTC_ALRMXR_WDAY_SHIFT 24 >> +#define STM32_RTC_ALRMXR_WDAY GENMASK(27, 24) >> +#define STM32_RTC_ALRMXR_DATE_MASK BIT(31) >> + >> +/* STM32_RTC_WPR key constants */ >> +#define RTC_WPR_1ST_KEY 0xCA >> +#define RTC_WPR_2ND_KEY 0x53 >> +#define RTC_WPR_WRONG_KEY 0xFF >> + >> +/* >> + * RTC registers are protected agains parasitic write access. >> + * PWR_CR_DBP bit must be set to enable write access to RTC registers. >> + */ >> +/* STM32_PWR_CR */ >> +#define PWR_CR 0x00 >> +/* STM32_PWR_CR bit field */ >> +#define PWR_CR_DBP BIT(8) >> + >> +static struct regmap *dbp; >> + >> +struct stm32_rtc { >> + struct rtc_device *rtc_dev; >> + void __iomem *base; >> + struct clk *ck_rtc; >> + spinlock_t lock; /* Protects registers accesses */ >> + int irq_alarm; >> +}; >> + >> +static void stm32_rtc_wpr_unlock(struct stm32_rtc *rtc) >> +{ >> + writel_relaxed(RTC_WPR_1ST_KEY, rtc->base + STM32_RTC_WPR); >> + writel_relaxed(RTC_WPR_2ND_KEY, rtc->base + STM32_RTC_WPR); >> +} >> + >> +static void stm32_rtc_wpr_lock(struct stm32_rtc *rtc) >> +{ >> + writel_relaxed(RTC_WPR_WRONG_KEY, rtc->base + STM32_RTC_WPR); >> +} >> + >> +static int stm32_rtc_enter_init_mode(struct stm32_rtc *rtc) >> +{ >> + unsigned int isr = readl_relaxed(rtc->base + STM32_RTC_ISR); >> + >> + if (!(isr & STM32_RTC_ISR_INITF)) { >> + isr |= STM32_RTC_ISR_INIT; >> + writel_relaxed(isr, rtc->base + STM32_RTC_ISR); >> + >> + /* >> + * It takes around 2 ck_rtc 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 >> + * 1MHz, we poll every 10 us with a timeout of 100ms. >> + */ >> + return readl_relaxed_poll_timeout_atomic( >> + rtc->base + STM32_RTC_ISR, >> + isr, (isr & STM32_RTC_ISR_INITF), >> + 10, 100000); >> + } >> + >> + return 0; >> +} >> + >> +static void stm32_rtc_exit_init_mode(struct stm32_rtc *rtc) >> +{ >> + unsigned int isr = readl_relaxed(rtc->base + STM32_RTC_ISR); >> + >> + isr &= ~STM32_RTC_ISR_INIT; >> + writel_relaxed(isr, rtc->base + STM32_RTC_ISR); >> +} >> + >> +static int stm32_rtc_wait_sync(struct stm32_rtc *rtc) >> +{ >> + unsigned int isr = readl_relaxed(rtc->base + STM32_RTC_ISR); >> + >> + isr &= ~STM32_RTC_ISR_RSF; >> + writel_relaxed(isr, rtc->base + STM32_RTC_ISR); >> + >> + /* >> + * Wait for RSF to be set to ensure the calendar registers are >> + * synchronised, it takes around 2 ck_rtc clock cycles >> + */ >> + return readl_relaxed_poll_timeout_atomic(rtc->base + STM32_RTC_ISR, >> + isr, >> + (isr & STM32_RTC_ISR_RSF), >> + 10, 100000); >> +} >> + >> +static irqreturn_t stm32_rtc_alarm_irq(int irq, void *dev_id) >> +{ >> + struct stm32_rtc *rtc = (struct stm32_rtc *)dev_id; >> + unsigned int isr, cr; >> + >> + mutex_lock(&rtc->rtc_dev->ops_lock); >> + >> + isr = readl_relaxed(rtc->base + STM32_RTC_ISR); >> + cr = readl_relaxed(rtc->base + STM32_RTC_CR); >> + >> + if ((isr & STM32_RTC_ISR_ALRAF) && >> + (cr & STM32_RTC_CR_ALRAIE)) { >> + /* Alarm A flag - Alarm interrupt */ >> + dev_dbg(&rtc->rtc_dev->dev, "Alarm occurred\n"); >> + >> + /* Pass event to the kernel */ >> + rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF); >> + >> + /* Clear event flag, otherwise new events won't be received */ >> + writel_relaxed(isr & ~STM32_RTC_ISR_ALRAF, >> + rtc->base + STM32_RTC_ISR); >> + } >> + >> + mutex_unlock(&rtc->rtc_dev->ops_lock); >> + >> + return IRQ_HANDLED; >> +} >> + >> +/* Convert rtc_time structure from bin to bcd format */ >> +static void tm2bcd(struct rtc_time *tm) >> +{ >> + tm->tm_sec = bin2bcd(tm->tm_sec); >> + tm->tm_min = bin2bcd(tm->tm_min); >> + tm->tm_hour = bin2bcd(tm->tm_hour); >> + >> + tm->tm_mday = bin2bcd(tm->tm_mday); >> + tm->tm_mon = bin2bcd(tm->tm_mon + 1); >> + tm->tm_year = bin2bcd(tm->tm_year - 100); >> + /* >> + * Number of days since Sunday >> + * - on kernel side, 0=Sunday...6=Saturday >> + * - on rtc side, 0=invalid,1=Monday...7=Sunday >> + */ >> + tm->tm_wday = (!tm->tm_wday) ? 7 : tm->tm_wday; >> +} >> + >> +/* Convert rtc_time structure from bcd to bin format */ >> +static void bcd2tm(struct rtc_time *tm) >> +{ >> + tm->tm_sec = bcd2bin(tm->tm_sec); >> + tm->tm_min = bcd2bin(tm->tm_min); >> + tm->tm_hour = bcd2bin(tm->tm_hour); >> + >> + tm->tm_mday = bcd2bin(tm->tm_mday); >> + tm->tm_mon = bcd2bin(tm->tm_mon) - 1; >> + tm->tm_year = bcd2bin(tm->tm_year) + 100; >> + /* >> + * Number of days since Sunday >> + * - on kernel side, 0=Sunday...6=Saturday >> + * - on rtc side, 0=invalid,1=Monday...7=Sunday >> + */ >> + tm->tm_wday %= 7; >> +} >> + >> +static int stm32_rtc_read_time(struct device *dev, struct rtc_time *tm) >> +{ >> + struct stm32_rtc *rtc = dev_get_drvdata(dev); >> + unsigned int tr, dr; >> + unsigned long irqflags; >> + >> + spin_lock_irqsave(&rtc->lock, irqflags); >> + >> + /* Time and Date in BCD format */ >> + tr = readl_relaxed(rtc->base + STM32_RTC_TR); >> + dr = readl_relaxed(rtc->base + STM32_RTC_DR); >> + >> + spin_unlock_irqrestore(&rtc->lock, irqflags); >> + >> + tm->tm_sec = (tr & STM32_RTC_TR_SEC) >> STM32_RTC_TR_SEC_SHIFT; >> + tm->tm_min = (tr & STM32_RTC_TR_MIN) >> STM32_RTC_TR_MIN_SHIFT; >> + tm->tm_hour = (tr & STM32_RTC_TR_HOUR) >> STM32_RTC_TR_HOUR_SHIFT; >> + >> + tm->tm_mday = (dr & STM32_RTC_DR_DATE) >> STM32_RTC_DR_DATE_SHIFT; >> + tm->tm_mon = (dr & STM32_RTC_DR_MONTH) >> STM32_RTC_DR_MONTH_SHIFT; >> + tm->tm_year = (dr & STM32_RTC_DR_YEAR) >> STM32_RTC_DR_YEAR_SHIFT; >> + tm->tm_wday = (dr & STM32_RTC_DR_WDAY) >> STM32_RTC_DR_WDAY_SHIFT; >> + >> + /* We don't report tm_yday and tm_isdst */ >> + >> + bcd2tm(tm); >> + >> + if (rtc_valid_tm(tm) < 0) { >> + dev_err(dev, "%s: rtc_time is not valid.\n", __func__); >> + return -EINVAL; >> + } >> + >> + return 0; >> +} >> + >> +static int stm32_rtc_set_time(struct device *dev, struct rtc_time *tm) >> +{ >> + struct stm32_rtc *rtc = dev_get_drvdata(dev); >> + unsigned int tr, dr; >> + unsigned long irqflags; >> + int ret = 0; >> + >> + if (rtc_valid_tm(tm) < 0) { >> + dev_err(dev, "%s: rtc_time is not valid.\n", __func__); >> + return -EINVAL; >> + } >> + >> + tm2bcd(tm); >> + >> + /* Time in BCD format */ >> + tr = ((tm->tm_sec << STM32_RTC_TR_SEC_SHIFT) & STM32_RTC_TR_SEC) | >> + ((tm->tm_min << STM32_RTC_TR_MIN_SHIFT) & STM32_RTC_TR_MIN) | >> + ((tm->tm_hour << STM32_RTC_TR_HOUR_SHIFT) & STM32_RTC_TR_HOUR); >> + >> + /* Date in BCD format */ >> + dr = ((tm->tm_mday << STM32_RTC_DR_DATE_SHIFT) & STM32_RTC_DR_DATE) | >> + ((tm->tm_mon << STM32_RTC_DR_MONTH_SHIFT) & STM32_RTC_DR_MONTH) | >> + ((tm->tm_year << STM32_RTC_DR_YEAR_SHIFT) & STM32_RTC_DR_YEAR) | >> + ((tm->tm_wday << STM32_RTC_DR_WDAY_SHIFT) & STM32_RTC_DR_WDAY); >> + >> + spin_lock_irqsave(&rtc->lock, irqflags); >> + >> + stm32_rtc_wpr_unlock(rtc); >> + >> + ret = stm32_rtc_enter_init_mode(rtc); >> + if (ret) { >> + dev_err(dev, "Can't enter in init mode. Set time aborted.\n"); >> + goto end; >> + } >> + >> + writel_relaxed(tr, rtc->base + STM32_RTC_TR); >> + writel_relaxed(dr, rtc->base + STM32_RTC_DR); >> + >> + stm32_rtc_exit_init_mode(rtc); >> + >> + ret = stm32_rtc_wait_sync(rtc); >> +end: >> + stm32_rtc_wpr_lock(rtc); >> + >> + spin_unlock_irqrestore(&rtc->lock, irqflags); >> + >> + return ret; >> +} >> + >> +static int stm32_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) >> +{ >> + struct stm32_rtc *rtc = dev_get_drvdata(dev); >> + struct rtc_time *tm = &alrm->time; >> + unsigned int alrmar, cr, isr; >> + unsigned long irqflags; >> + >> + spin_lock_irqsave(&rtc->lock, irqflags); >> + >> + alrmar = readl_relaxed(rtc->base + STM32_RTC_ALRMAR); >> + cr = readl_relaxed(rtc->base + STM32_RTC_CR); >> + isr = readl_relaxed(rtc->base + STM32_RTC_ISR); >> + >> + spin_unlock_irqrestore(&rtc->lock, irqflags); >> + >> + if (alrmar & STM32_RTC_ALRMXR_DATE_MASK) { >> + /* >> + * Date/day doesn't matter in Alarm comparison so alarm >> + * triggers every day >> + */ >> + tm->tm_mday = -1; >> + tm->tm_wday = -1; >> + } else { >> + if (alrmar & STM32_RTC_ALRMXR_WDSEL) { >> + /* Alarm is set to a day of week */ >> + tm->tm_mday = -1; >> + tm->tm_wday = (alrmar & STM32_RTC_ALRMXR_WDAY) >> >> + STM32_RTC_ALRMXR_WDAY_SHIFT; >> + tm->tm_wday %= 7; >> + } else { >> + /* Alarm is set to a day of month */ >> + tm->tm_wday = -1; >> + tm->tm_mday = (alrmar & STM32_RTC_ALRMXR_DATE) >> >> + STM32_RTC_ALRMXR_DATE_SHIFT; >> + } >> + } >> + >> + if (alrmar & STM32_RTC_ALRMXR_HOUR_MASK) { >> + /* Hours don't matter in Alarm comparison */ >> + tm->tm_hour = -1; >> + } else { >> + tm->tm_hour = (alrmar & STM32_RTC_ALRMXR_HOUR) >> >> + STM32_RTC_ALRMXR_HOUR_SHIFT; >> + if (alrmar & STM32_RTC_ALRMXR_PM) >> + tm->tm_hour += 12; >> + } >> + >> + if (alrmar & STM32_RTC_ALRMXR_MIN_MASK) { >> + /* Minutes don't matter in Alarm comparison */ >> + tm->tm_min = -1; >> + } else { >> + tm->tm_min = (alrmar & STM32_RTC_ALRMXR_MIN) >> >> + STM32_RTC_ALRMXR_MIN_SHIFT; >> + } >> + >> + if (alrmar & STM32_RTC_ALRMXR_SEC_MASK) { >> + /* Seconds don't matter in Alarm comparison */ >> + tm->tm_sec = -1; >> + } else { >> + tm->tm_sec = (alrmar & STM32_RTC_ALRMXR_SEC) >> >> + STM32_RTC_ALRMXR_SEC_SHIFT; >> + } >> + >> + bcd2tm(tm); >> + >> + alrm->enabled = (cr & STM32_RTC_CR_ALRAE) ? 1 : 0; >> + alrm->pending = (isr & STM32_RTC_ISR_ALRAF) ? 1 : 0; >> + >> + return 0; >> +} >> + >> +static int stm32_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) >> +{ >> + struct stm32_rtc *rtc = dev_get_drvdata(dev); >> + unsigned long irqflags; >> + unsigned int isr, cr; >> + >> + spin_lock_irqsave(&rtc->lock, irqflags); >> + >> + cr = readl_relaxed(rtc->base + STM32_RTC_CR); >> + >> + stm32_rtc_wpr_unlock(rtc); >> + >> + /* We expose Alarm A to the kernel */ >> + if (enabled) >> + cr |= (STM32_RTC_CR_ALRAIE | STM32_RTC_CR_ALRAE); >> + else >> + cr &= ~(STM32_RTC_CR_ALRAIE | STM32_RTC_CR_ALRAE); >> + writel_relaxed(cr, rtc->base + STM32_RTC_CR); >> + >> + /* Clear event irqflags, otherwise new events won't be received */ >> + isr = readl_relaxed(rtc->base + STM32_RTC_ISR); >> + isr &= ~STM32_RTC_ISR_ALRAF; >> + writel_relaxed(isr, rtc->base + STM32_RTC_ISR); >> + >> + stm32_rtc_wpr_lock(rtc); >> + >> + spin_unlock_irqrestore(&rtc->lock, irqflags); >> + >> + return 0; >> +} >> + >> +static int stm32_rtc_valid_alrm(struct stm32_rtc *rtc, struct rtc_time *tm) >> +{ >> + unsigned int cur_day, cur_mon, cur_year, cur_hour, cur_min, cur_sec; >> + unsigned int dr = readl_relaxed(rtc->base + STM32_RTC_DR); >> + unsigned int tr = readl_relaxed(rtc->base + STM32_RTC_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; >> + >> + /* >> + * 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; >> + >> + return -EINVAL; >> +} >> + >> +static int stm32_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) >> +{ >> + struct stm32_rtc *rtc = dev_get_drvdata(dev); >> + struct rtc_time *tm = &alrm->time; >> + unsigned long irqflags; >> + unsigned int cr, isr, alrmar; >> + int ret = 0; >> + >> + if (rtc_valid_tm(tm)) { >> + dev_err(dev, "Alarm time not valid.\n"); >> + return -EINVAL; >> + } >> + >> + 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) { >> + dev_err(dev, "Alarm can be set only on upcoming month.\n"); >> + return -EINVAL; >> + } >> + >> + alrmar = 0; >> + /* tm_year and tm_mon are not used because not supported by RTC */ >> + alrmar |= (tm->tm_mday << STM32_RTC_ALRMXR_DATE_SHIFT) & >> + STM32_RTC_ALRMXR_DATE; >> + /* 24-hour format */ >> + alrmar &= ~STM32_RTC_ALRMXR_PM; >> + alrmar |= (tm->tm_hour << STM32_RTC_ALRMXR_HOUR_SHIFT) & >> + STM32_RTC_ALRMXR_HOUR; >> + alrmar |= (tm->tm_min << STM32_RTC_ALRMXR_MIN_SHIFT) & >> + STM32_RTC_ALRMXR_MIN; >> + alrmar |= (tm->tm_sec << STM32_RTC_ALRMXR_SEC_SHIFT) & >> + STM32_RTC_ALRMXR_SEC; >> + >> + spin_lock_irqsave(&rtc->lock, irqflags); >> + >> + stm32_rtc_wpr_unlock(rtc); >> + >> + /* Disable Alarm */ >> + cr = readl_relaxed(rtc->base + STM32_RTC_CR); >> + cr &= ~STM32_RTC_CR_ALRAE; >> + writel_relaxed(cr, rtc->base + STM32_RTC_CR); >> + >> + /* >> + * Poll Alarm write flag to be sure that Alarm update is allowed: it >> + * takes around 2 ck_rtc clock cycles >> + */ >> + ret = readl_relaxed_poll_timeout_atomic(rtc->base + STM32_RTC_ISR, >> + isr, >> + (isr & STM32_RTC_ISR_ALRAWF), >> + 10, 100000); >> + >> + if (ret) { >> + dev_err(dev, "Alarm update not allowed\n"); >> + goto end; >> + } >> + >> + /* Write to Alarm register */ >> + writel_relaxed(alrmar, rtc->base + STM32_RTC_ALRMAR); >> + >> + if (alrm->enabled) >> + stm32_rtc_alarm_irq_enable(dev, 1); >> + else >> + stm32_rtc_alarm_irq_enable(dev, 0); >> + >> +end: >> + stm32_rtc_wpr_lock(rtc); >> + >> + spin_unlock_irqrestore(&rtc->lock, irqflags); >> + >> + return ret; >> +} >> + >> +static const struct rtc_class_ops stm32_rtc_ops = { >> + .read_time = stm32_rtc_read_time, >> + .set_time = stm32_rtc_set_time, >> + .read_alarm = stm32_rtc_read_alarm, >> + .set_alarm = stm32_rtc_set_alarm, >> + .alarm_irq_enable = stm32_rtc_alarm_irq_enable, >> +}; >> + >> +#ifdef CONFIG_OF >> +static const struct of_device_id stm32_rtc_of_match[] = { >> + { .compatible = "st,stm32-rtc" }, >> + {} >> +}; >> +MODULE_DEVICE_TABLE(of, stm32_rtc_of_match); >> +#endif >> + >> +static int stm32_rtc_init(struct platform_device *pdev, >> + struct stm32_rtc *rtc) >> +{ >> + unsigned int prer, pred_a, pred_s, pred_a_max, pred_s_max, cr; >> + unsigned int rate; >> + unsigned long irqflags; >> + int ret = 0; >> + >> + rate = clk_get_rate(rtc->ck_rtc); >> + >> + /* 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; >> + pred_s_max = STM32_RTC_PRER_PRED_S >> STM32_RTC_PRER_PRED_S_SHIFT; >> + >> + for (pred_a = pred_a_max; pred_a >= 0; pred_a--) { >> + pred_s = (rate / (pred_a + 1)) - 1; >> + >> + 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)) { >> + pred_a = pred_a_max; >> + pred_s = (rate / (pred_a + 1)) - 1; >> + >> + dev_warn(&pdev->dev, "ck_rtc is %s\n", >> + (rate - ((pred_a + 1) * (pred_s + 1)) < 0) ? >> + "fast" : "slow"); >> + } >> + >> + spin_lock_irqsave(&rtc->lock, irqflags); >> + >> + stm32_rtc_wpr_unlock(rtc); >> + >> + ret = stm32_rtc_enter_init_mode(rtc); >> + if (ret) { >> + dev_err(&pdev->dev, >> + "Can't enter in init mode. Prescaler config failed.\n"); >> + goto end; >> + } >> + >> + prer = (pred_s << STM32_RTC_PRER_PRED_S_SHIFT) & STM32_RTC_PRER_PRED_S; >> + writel_relaxed(prer, rtc->base + STM32_RTC_PRER); >> + prer |= (pred_a << STM32_RTC_PRER_PRED_A_SHIFT) & STM32_RTC_PRER_PRED_A; >> + writel_relaxed(prer, rtc->base + STM32_RTC_PRER); >> + >> + /* Force 24h time format */ >> + cr = readl_relaxed(rtc->base + STM32_RTC_CR); >> + cr &= ~STM32_RTC_CR_FMT; >> + writel_relaxed(cr, rtc->base + STM32_RTC_CR); >> + >> + stm32_rtc_exit_init_mode(rtc); >> + >> + ret = stm32_rtc_wait_sync(rtc); >> +end: >> + stm32_rtc_wpr_lock(rtc); >> + >> + spin_unlock_irqrestore(&rtc->lock, irqflags); >> + >> + return ret; >> +} >> + >> +static int stm32_rtc_probe(struct platform_device *pdev) >> +{ >> + struct stm32_rtc *rtc; >> + struct resource *res; >> + int ret; >> + >> + rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); >> + if (!rtc) >> + return -ENOMEM; >> + >> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); >> + rtc->base = devm_ioremap_resource(&pdev->dev, res); >> + if (IS_ERR(rtc->base)) >> + return PTR_ERR(rtc->base); >> + >> + dbp = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "st,syscfg"); >> + if (IS_ERR(dbp)) { >> + dev_err(&pdev->dev, "no st,syscfg\n"); >> + return PTR_ERR(dbp); >> + } >> + >> + spin_lock_init(&rtc->lock); >> + >> + 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); >> + } >> + >> + ret = clk_prepare_enable(rtc->ck_rtc); >> + if (ret) >> + return ret; >> + >> + regmap_update_bits(dbp, PWR_CR, PWR_CR_DBP, PWR_CR_DBP); >> + >> + /* >> + * 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 >> + * changed). That's why we cannot rely on this flag to know if RTC >> + * init has to be done. >> + */ >> + ret = stm32_rtc_init(pdev, rtc); >> + if (ret) >> + goto err; >> + >> + rtc->irq_alarm = platform_get_irq(pdev, 0); >> + if (rtc->irq_alarm <= 0) { >> + dev_err(&pdev->dev, "no alarm irq\n"); >> + ret = rtc->irq_alarm; >> + goto err; >> + } >> + >> + platform_set_drvdata(pdev, rtc); >> + >> + ret = device_init_wakeup(&pdev->dev, true); >> + if (ret) >> + dev_warn(&pdev->dev, >> + "alarm won't be able to wake up the system"); >> + >> + rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, pdev->name, >> + &stm32_rtc_ops, THIS_MODULE); >> + if (IS_ERR(rtc->rtc_dev)) { >> + ret = PTR_ERR(rtc->rtc_dev); >> + dev_err(&pdev->dev, "rtc device registration failed, err=%d\n", >> + ret); >> + goto err; >> + } >> + >> + /* Handle RTC alarm interrupts */ >> + ret = devm_request_threaded_irq(&pdev->dev, rtc->irq_alarm, NULL, >> + stm32_rtc_alarm_irq, >> + IRQF_TRIGGER_RISING | IRQF_ONESHOT, >> + pdev->name, rtc); >> + if (ret) { >> + dev_err(&pdev->dev, "IRQ%d (alarm interrupt) already claimed\n", >> + rtc->irq_alarm); >> + goto err; >> + } >> + >> + /* >> + * If INITS flag is reset (calendar year field set to 0x00), calendar >> + * must be initialized >> + */ >> + if (!(readl_relaxed(rtc->base + STM32_RTC_ISR) & STM32_RTC_ISR_INITS)) >> + dev_warn(&pdev->dev, "Date/Time must be initialized\n"); >> + >> + return 0; >> +err: >> + clk_disable_unprepare(rtc->ck_rtc); >> + >> + regmap_update_bits(dbp, PWR_CR, PWR_CR_DBP, ~PWR_CR_DBP); >> + >> + device_init_wakeup(&pdev->dev, false); >> + >> + return ret; >> +} >> + >> +static int __exit stm32_rtc_remove(struct platform_device *pdev) >> +{ >> + struct stm32_rtc *rtc = platform_get_drvdata(pdev); >> + unsigned int cr; >> + >> + /* Disable interrupts */ >> + stm32_rtc_wpr_unlock(rtc); >> + cr = readl_relaxed(rtc->base + STM32_RTC_CR); >> + cr &= ~STM32_RTC_CR_ALRAIE; >> + writel_relaxed(cr, rtc->base + STM32_RTC_CR); >> + stm32_rtc_wpr_lock(rtc); >> + >> + clk_disable_unprepare(rtc->ck_rtc); >> + >> + /* Enable backup domain write protection */ >> + regmap_update_bits(dbp, PWR_CR, PWR_CR_DBP, ~PWR_CR_DBP); >> + >> + device_init_wakeup(&pdev->dev, false); >> + >> + return 0; >> +} >> + >> +#ifdef CONFIG_PM_SLEEP >> +static int stm32_rtc_suspend(struct device *dev) >> +{ >> + struct stm32_rtc *rtc = dev_get_drvdata(dev); >> + >> + if (device_may_wakeup(dev)) >> + return enable_irq_wake(rtc->irq_alarm); >> + >> + return 0; >> +} >> + >> +static int stm32_rtc_resume(struct device *dev) >> +{ >> + struct stm32_rtc *rtc = dev_get_drvdata(dev); >> + int ret = 0; >> + >> + ret = stm32_rtc_wait_sync(rtc); >> + if (ret < 0) >> + return ret; >> + >> + if (device_may_wakeup(dev)) >> + return disable_irq_wake(rtc->irq_alarm); >> + >> + return ret; >> +} >> +#endif >> + >> +static SIMPLE_DEV_PM_OPS(stm32_rtc_pm_ops, >> + stm32_rtc_suspend, stm32_rtc_resume); >> + >> +static struct platform_driver stm32_rtc_driver = { >> + .probe = stm32_rtc_probe, >> + .remove = stm32_rtc_remove, >> + .driver = { >> + .name = DRIVER_NAME, >> + .pm = &stm32_rtc_pm_ops, >> + .of_match_table = stm32_rtc_of_match, >> + }, >> +}; >> + >> +module_platform_driver(stm32_rtc_driver); >> + >> +MODULE_ALIAS("platform:" DRIVER_NAME); >> +MODULE_AUTHOR("Amelie Delaunay "); >> +MODULE_DESCRIPTION("STMicroelectronics STM32 Real Time Clock driver"); >> +MODULE_LICENSE("GPL v2"); > > Looks much better now. > > Reviewed-by: Mathieu Poirier > >> -- >> 1.9.1 >> >> >> _______________________________________________ >> linux-arm-kernel mailing list >> linux-arm-kernel at lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel