diff options
Diffstat (limited to 'drivers/rtc/rtc-sunxi.c')
| -rw-r--r-- | drivers/rtc/rtc-sunxi.c | 488 |
1 files changed, 488 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-sunxi.c b/drivers/rtc/rtc-sunxi.c new file mode 100644 index 000000000..5d019e3a8 --- /dev/null +++ b/drivers/rtc/rtc-sunxi.c @@ -0,0 +1,488 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * An RTC driver for Allwinner A10/A20 + * + * Copyright (c) 2013, Carlo Caione <carlo.caione@gmail.com> + */ + +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/rtc.h> +#include <linux/types.h> + +#define SUNXI_LOSC_CTRL 0x0000 +#define SUNXI_LOSC_CTRL_RTC_HMS_ACC BIT(8) +#define SUNXI_LOSC_CTRL_RTC_YMD_ACC BIT(7) + +#define SUNXI_RTC_YMD 0x0004 + +#define SUNXI_RTC_HMS 0x0008 + +#define SUNXI_ALRM_DHMS 0x000c + +#define SUNXI_ALRM_EN 0x0014 +#define SUNXI_ALRM_EN_CNT_EN BIT(8) + +#define SUNXI_ALRM_IRQ_EN 0x0018 +#define SUNXI_ALRM_IRQ_EN_CNT_IRQ_EN BIT(0) + +#define SUNXI_ALRM_IRQ_STA 0x001c +#define SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND BIT(0) + +#define SUNXI_MASK_DH 0x0000001f +#define SUNXI_MASK_SM 0x0000003f +#define SUNXI_MASK_M 0x0000000f +#define SUNXI_MASK_LY 0x00000001 +#define SUNXI_MASK_D 0x00000ffe +#define SUNXI_MASK_M 0x0000000f + +#define SUNXI_GET(x, mask, shift) (((x) & ((mask) << (shift))) \ + >> (shift)) + +#define SUNXI_SET(x, mask, shift) (((x) & (mask)) << (shift)) + +/* + * Get date values + */ +#define SUNXI_DATE_GET_DAY_VALUE(x) SUNXI_GET(x, SUNXI_MASK_DH, 0) +#define SUNXI_DATE_GET_MON_VALUE(x) SUNXI_GET(x, SUNXI_MASK_M, 8) +#define SUNXI_DATE_GET_YEAR_VALUE(x, mask) SUNXI_GET(x, mask, 16) + +/* + * Get time values + */ +#define SUNXI_TIME_GET_SEC_VALUE(x) SUNXI_GET(x, SUNXI_MASK_SM, 0) +#define SUNXI_TIME_GET_MIN_VALUE(x) SUNXI_GET(x, SUNXI_MASK_SM, 8) +#define SUNXI_TIME_GET_HOUR_VALUE(x) SUNXI_GET(x, SUNXI_MASK_DH, 16) + +/* + * Get alarm values + */ +#define SUNXI_ALRM_GET_SEC_VALUE(x) SUNXI_GET(x, SUNXI_MASK_SM, 0) +#define SUNXI_ALRM_GET_MIN_VALUE(x) SUNXI_GET(x, SUNXI_MASK_SM, 8) +#define SUNXI_ALRM_GET_HOUR_VALUE(x) SUNXI_GET(x, SUNXI_MASK_DH, 16) + +/* + * Set date values + */ +#define SUNXI_DATE_SET_DAY_VALUE(x) SUNXI_DATE_GET_DAY_VALUE(x) +#define SUNXI_DATE_SET_MON_VALUE(x) SUNXI_SET(x, SUNXI_MASK_M, 8) +#define SUNXI_DATE_SET_YEAR_VALUE(x, mask) SUNXI_SET(x, mask, 16) +#define SUNXI_LEAP_SET_VALUE(x, shift) SUNXI_SET(x, SUNXI_MASK_LY, shift) + +/* + * Set time values + */ +#define SUNXI_TIME_SET_SEC_VALUE(x) SUNXI_TIME_GET_SEC_VALUE(x) +#define SUNXI_TIME_SET_MIN_VALUE(x) SUNXI_SET(x, SUNXI_MASK_SM, 8) +#define SUNXI_TIME_SET_HOUR_VALUE(x) SUNXI_SET(x, SUNXI_MASK_DH, 16) + +/* + * Set alarm values + */ +#define SUNXI_ALRM_SET_SEC_VALUE(x) SUNXI_ALRM_GET_SEC_VALUE(x) +#define SUNXI_ALRM_SET_MIN_VALUE(x) SUNXI_SET(x, SUNXI_MASK_SM, 8) +#define SUNXI_ALRM_SET_HOUR_VALUE(x) SUNXI_SET(x, SUNXI_MASK_DH, 16) +#define SUNXI_ALRM_SET_DAY_VALUE(x) SUNXI_SET(x, SUNXI_MASK_D, 21) + +/* + * Time unit conversions + */ +#define SEC_IN_MIN 60 +#define SEC_IN_HOUR (60 * SEC_IN_MIN) +#define SEC_IN_DAY (24 * SEC_IN_HOUR) + +/* + * The year parameter passed to the driver is usually an offset relative to + * the year 1900. This macro is used to convert this offset to another one + * relative to the minimum year allowed by the hardware. + */ +#define SUNXI_YEAR_OFF(x) ((x)->min - 1900) + +/* + * min and max year are arbitrary set considering the limited range of the + * hardware register field + */ +struct sunxi_rtc_data_year { + unsigned int min; /* min year allowed */ + unsigned int max; /* max year allowed */ + unsigned int mask; /* mask for the year field */ + unsigned char leap_shift; /* bit shift to get the leap year */ +}; + +static const struct sunxi_rtc_data_year data_year_param[] = { + [0] = { + .min = 2010, + .max = 2073, + .mask = 0x3f, + .leap_shift = 22, + }, + [1] = { + .min = 1970, + .max = 2225, + .mask = 0xff, + .leap_shift = 24, + }, +}; + +struct sunxi_rtc_dev { + struct rtc_device *rtc; + struct device *dev; + const struct sunxi_rtc_data_year *data_year; + void __iomem *base; + int irq; +}; + +static irqreturn_t sunxi_rtc_alarmirq(int irq, void *id) +{ + struct sunxi_rtc_dev *chip = (struct sunxi_rtc_dev *) id; + u32 val; + + val = readl(chip->base + SUNXI_ALRM_IRQ_STA); + + if (val & SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND) { + val |= SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND; + writel(val, chip->base + SUNXI_ALRM_IRQ_STA); + + rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF); + + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + +static void sunxi_rtc_setaie(unsigned int to, struct sunxi_rtc_dev *chip) +{ + u32 alrm_val = 0; + u32 alrm_irq_val = 0; + + if (to) { + alrm_val = readl(chip->base + SUNXI_ALRM_EN); + alrm_val |= SUNXI_ALRM_EN_CNT_EN; + + alrm_irq_val = readl(chip->base + SUNXI_ALRM_IRQ_EN); + alrm_irq_val |= SUNXI_ALRM_IRQ_EN_CNT_IRQ_EN; + } else { + writel(SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND, + chip->base + SUNXI_ALRM_IRQ_STA); + } + + writel(alrm_val, chip->base + SUNXI_ALRM_EN); + writel(alrm_irq_val, chip->base + SUNXI_ALRM_IRQ_EN); +} + +static int sunxi_rtc_getalarm(struct device *dev, struct rtc_wkalrm *wkalrm) +{ + struct sunxi_rtc_dev *chip = dev_get_drvdata(dev); + struct rtc_time *alrm_tm = &wkalrm->time; + u32 alrm; + u32 alrm_en; + u32 date; + + alrm = readl(chip->base + SUNXI_ALRM_DHMS); + date = readl(chip->base + SUNXI_RTC_YMD); + + alrm_tm->tm_sec = SUNXI_ALRM_GET_SEC_VALUE(alrm); + alrm_tm->tm_min = SUNXI_ALRM_GET_MIN_VALUE(alrm); + alrm_tm->tm_hour = SUNXI_ALRM_GET_HOUR_VALUE(alrm); + + alrm_tm->tm_mday = SUNXI_DATE_GET_DAY_VALUE(date); + alrm_tm->tm_mon = SUNXI_DATE_GET_MON_VALUE(date); + alrm_tm->tm_year = SUNXI_DATE_GET_YEAR_VALUE(date, + chip->data_year->mask); + + alrm_tm->tm_mon -= 1; + + /* + * switch from (data_year->min)-relative offset to + * a (1900)-relative one + */ + alrm_tm->tm_year += SUNXI_YEAR_OFF(chip->data_year); + + alrm_en = readl(chip->base + SUNXI_ALRM_IRQ_EN); + if (alrm_en & SUNXI_ALRM_EN_CNT_EN) + wkalrm->enabled = 1; + + return 0; +} + +static int sunxi_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) +{ + struct sunxi_rtc_dev *chip = dev_get_drvdata(dev); + u32 date, time; + + /* + * read again in case it changes + */ + do { + date = readl(chip->base + SUNXI_RTC_YMD); + time = readl(chip->base + SUNXI_RTC_HMS); + } while ((date != readl(chip->base + SUNXI_RTC_YMD)) || + (time != readl(chip->base + SUNXI_RTC_HMS))); + + rtc_tm->tm_sec = SUNXI_TIME_GET_SEC_VALUE(time); + rtc_tm->tm_min = SUNXI_TIME_GET_MIN_VALUE(time); + rtc_tm->tm_hour = SUNXI_TIME_GET_HOUR_VALUE(time); + + rtc_tm->tm_mday = SUNXI_DATE_GET_DAY_VALUE(date); + rtc_tm->tm_mon = SUNXI_DATE_GET_MON_VALUE(date); + rtc_tm->tm_year = SUNXI_DATE_GET_YEAR_VALUE(date, + chip->data_year->mask); + + rtc_tm->tm_mon -= 1; + + /* + * switch from (data_year->min)-relative offset to + * a (1900)-relative one + */ + rtc_tm->tm_year += SUNXI_YEAR_OFF(chip->data_year); + + return 0; +} + +static int sunxi_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm) +{ + struct sunxi_rtc_dev *chip = dev_get_drvdata(dev); + struct rtc_time *alrm_tm = &wkalrm->time; + struct rtc_time tm_now; + u32 alrm; + time64_t diff; + unsigned long time_gap; + unsigned long time_gap_day; + unsigned long time_gap_hour; + unsigned long time_gap_min; + int ret; + + ret = sunxi_rtc_gettime(dev, &tm_now); + if (ret < 0) { + dev_err(dev, "Error in getting time\n"); + return -EINVAL; + } + + diff = rtc_tm_sub(alrm_tm, &tm_now); + if (diff <= 0) { + dev_err(dev, "Date to set in the past\n"); + return -EINVAL; + } + + if (diff > 255 * SEC_IN_DAY) { + dev_err(dev, "Day must be in the range 0 - 255\n"); + return -EINVAL; + } + + time_gap = diff; + time_gap_day = time_gap / SEC_IN_DAY; + time_gap -= time_gap_day * SEC_IN_DAY; + time_gap_hour = time_gap / SEC_IN_HOUR; + time_gap -= time_gap_hour * SEC_IN_HOUR; + time_gap_min = time_gap / SEC_IN_MIN; + time_gap -= time_gap_min * SEC_IN_MIN; + + sunxi_rtc_setaie(0, chip); + writel(0, chip->base + SUNXI_ALRM_DHMS); + usleep_range(100, 300); + + alrm = SUNXI_ALRM_SET_SEC_VALUE(time_gap) | + SUNXI_ALRM_SET_MIN_VALUE(time_gap_min) | + SUNXI_ALRM_SET_HOUR_VALUE(time_gap_hour) | + SUNXI_ALRM_SET_DAY_VALUE(time_gap_day); + writel(alrm, chip->base + SUNXI_ALRM_DHMS); + + writel(0, chip->base + SUNXI_ALRM_IRQ_EN); + writel(SUNXI_ALRM_IRQ_EN_CNT_IRQ_EN, chip->base + SUNXI_ALRM_IRQ_EN); + + sunxi_rtc_setaie(wkalrm->enabled, chip); + + return 0; +} + +static int sunxi_rtc_wait(struct sunxi_rtc_dev *chip, int offset, + unsigned int mask, unsigned int ms_timeout) +{ + const unsigned long timeout = jiffies + msecs_to_jiffies(ms_timeout); + u32 reg; + + do { + reg = readl(chip->base + offset); + reg &= mask; + + if (reg == mask) + return 0; + + } while (time_before(jiffies, timeout)); + + return -ETIMEDOUT; +} + +static int sunxi_rtc_settime(struct device *dev, struct rtc_time *rtc_tm) +{ + struct sunxi_rtc_dev *chip = dev_get_drvdata(dev); + u32 date = 0; + u32 time = 0; + unsigned int year; + + /* + * the input rtc_tm->tm_year is the offset relative to 1900. We use + * the SUNXI_YEAR_OFF macro to rebase it with respect to the min year + * allowed by the hardware + */ + + year = rtc_tm->tm_year + 1900; + if (year < chip->data_year->min || year > chip->data_year->max) { + dev_err(dev, "rtc only supports year in range %u - %u\n", + chip->data_year->min, chip->data_year->max); + return -EINVAL; + } + + rtc_tm->tm_year -= SUNXI_YEAR_OFF(chip->data_year); + rtc_tm->tm_mon += 1; + + date = SUNXI_DATE_SET_DAY_VALUE(rtc_tm->tm_mday) | + SUNXI_DATE_SET_MON_VALUE(rtc_tm->tm_mon) | + SUNXI_DATE_SET_YEAR_VALUE(rtc_tm->tm_year, + chip->data_year->mask); + + if (is_leap_year(year)) + date |= SUNXI_LEAP_SET_VALUE(1, chip->data_year->leap_shift); + + time = SUNXI_TIME_SET_SEC_VALUE(rtc_tm->tm_sec) | + SUNXI_TIME_SET_MIN_VALUE(rtc_tm->tm_min) | + SUNXI_TIME_SET_HOUR_VALUE(rtc_tm->tm_hour); + + writel(0, chip->base + SUNXI_RTC_HMS); + writel(0, chip->base + SUNXI_RTC_YMD); + + writel(time, chip->base + SUNXI_RTC_HMS); + + /* + * After writing the RTC HH-MM-SS register, the + * SUNXI_LOSC_CTRL_RTC_HMS_ACC bit is set and it will not + * be cleared until the real writing operation is finished + */ + + if (sunxi_rtc_wait(chip, SUNXI_LOSC_CTRL, + SUNXI_LOSC_CTRL_RTC_HMS_ACC, 50)) { + dev_err(dev, "Failed to set rtc time.\n"); + return -1; + } + + writel(date, chip->base + SUNXI_RTC_YMD); + + /* + * After writing the RTC YY-MM-DD register, the + * SUNXI_LOSC_CTRL_RTC_YMD_ACC bit is set and it will not + * be cleared until the real writing operation is finished + */ + + if (sunxi_rtc_wait(chip, SUNXI_LOSC_CTRL, + SUNXI_LOSC_CTRL_RTC_YMD_ACC, 50)) { + dev_err(dev, "Failed to set rtc time.\n"); + return -1; + } + + return 0; +} + +static int sunxi_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct sunxi_rtc_dev *chip = dev_get_drvdata(dev); + + if (!enabled) + sunxi_rtc_setaie(enabled, chip); + + return 0; +} + +static const struct rtc_class_ops sunxi_rtc_ops = { + .read_time = sunxi_rtc_gettime, + .set_time = sunxi_rtc_settime, + .read_alarm = sunxi_rtc_getalarm, + .set_alarm = sunxi_rtc_setalarm, + .alarm_irq_enable = sunxi_rtc_alarm_irq_enable +}; + +static const struct of_device_id sunxi_rtc_dt_ids[] = { + { .compatible = "allwinner,sun4i-a10-rtc", .data = &data_year_param[0] }, + { .compatible = "allwinner,sun7i-a20-rtc", .data = &data_year_param[1] }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, sunxi_rtc_dt_ids); + +static int sunxi_rtc_probe(struct platform_device *pdev) +{ + struct sunxi_rtc_dev *chip; + int ret; + + chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL); + if (!chip) + return -ENOMEM; + + platform_set_drvdata(pdev, chip); + chip->dev = &pdev->dev; + + chip->rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(chip->rtc)) + return PTR_ERR(chip->rtc); + + chip->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(chip->base)) + return PTR_ERR(chip->base); + + chip->irq = platform_get_irq(pdev, 0); + if (chip->irq < 0) + return chip->irq; + ret = devm_request_irq(&pdev->dev, chip->irq, sunxi_rtc_alarmirq, + 0, dev_name(&pdev->dev), chip); + if (ret) { + dev_err(&pdev->dev, "Could not request IRQ\n"); + return ret; + } + + chip->data_year = of_device_get_match_data(&pdev->dev); + if (!chip->data_year) { + dev_err(&pdev->dev, "Unable to setup RTC data\n"); + return -ENODEV; + } + + /* clear the alarm count value */ + writel(0, chip->base + SUNXI_ALRM_DHMS); + + /* disable alarm, not generate irq pending */ + writel(0, chip->base + SUNXI_ALRM_EN); + + /* disable alarm week/cnt irq, unset to cpu */ + writel(0, chip->base + SUNXI_ALRM_IRQ_EN); + + /* clear alarm week/cnt irq pending */ + writel(SUNXI_ALRM_IRQ_STA_CNT_IRQ_PEND, chip->base + + SUNXI_ALRM_IRQ_STA); + + chip->rtc->ops = &sunxi_rtc_ops; + + return devm_rtc_register_device(chip->rtc); +} + +static struct platform_driver sunxi_rtc_driver = { + .probe = sunxi_rtc_probe, + .driver = { + .name = "sunxi-rtc", + .of_match_table = sunxi_rtc_dt_ids, + }, +}; + +module_platform_driver(sunxi_rtc_driver); + +MODULE_DESCRIPTION("sunxi RTC driver"); +MODULE_AUTHOR("Carlo Caione <carlo.caione@gmail.com>"); +MODULE_LICENSE("GPL"); |