diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/rtc/rtc-sc27xx.c | 647 |
1 files changed, 647 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-sc27xx.c b/drivers/rtc/rtc-sc27xx.c new file mode 100644 index 000000000..ce7a2ddbb --- /dev/null +++ b/drivers/rtc/rtc-sc27xx.c @@ -0,0 +1,647 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2017 Spreadtrum Communications Inc. + * + */ + +#include <linux/bitops.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/rtc.h> + +#define SPRD_RTC_SEC_CNT_VALUE 0x0 +#define SPRD_RTC_MIN_CNT_VALUE 0x4 +#define SPRD_RTC_HOUR_CNT_VALUE 0x8 +#define SPRD_RTC_DAY_CNT_VALUE 0xc +#define SPRD_RTC_SEC_CNT_UPD 0x10 +#define SPRD_RTC_MIN_CNT_UPD 0x14 +#define SPRD_RTC_HOUR_CNT_UPD 0x18 +#define SPRD_RTC_DAY_CNT_UPD 0x1c +#define SPRD_RTC_SEC_ALM_UPD 0x20 +#define SPRD_RTC_MIN_ALM_UPD 0x24 +#define SPRD_RTC_HOUR_ALM_UPD 0x28 +#define SPRD_RTC_DAY_ALM_UPD 0x2c +#define SPRD_RTC_INT_EN 0x30 +#define SPRD_RTC_INT_RAW_STS 0x34 +#define SPRD_RTC_INT_CLR 0x38 +#define SPRD_RTC_INT_MASK_STS 0x3C +#define SPRD_RTC_SEC_ALM_VALUE 0x40 +#define SPRD_RTC_MIN_ALM_VALUE 0x44 +#define SPRD_RTC_HOUR_ALM_VALUE 0x48 +#define SPRD_RTC_DAY_ALM_VALUE 0x4c +#define SPRD_RTC_SPG_VALUE 0x50 +#define SPRD_RTC_SPG_UPD 0x54 +#define SPRD_RTC_PWR_CTRL 0x58 +#define SPRD_RTC_PWR_STS 0x5c +#define SPRD_RTC_SEC_AUXALM_UPD 0x60 +#define SPRD_RTC_MIN_AUXALM_UPD 0x64 +#define SPRD_RTC_HOUR_AUXALM_UPD 0x68 +#define SPRD_RTC_DAY_AUXALM_UPD 0x6c + +/* BIT & MASK definition for SPRD_RTC_INT_* registers */ +#define SPRD_RTC_SEC_EN BIT(0) +#define SPRD_RTC_MIN_EN BIT(1) +#define SPRD_RTC_HOUR_EN BIT(2) +#define SPRD_RTC_DAY_EN BIT(3) +#define SPRD_RTC_ALARM_EN BIT(4) +#define SPRD_RTC_HRS_FORMAT_EN BIT(5) +#define SPRD_RTC_AUXALM_EN BIT(6) +#define SPRD_RTC_SPG_UPD_EN BIT(7) +#define SPRD_RTC_SEC_UPD_EN BIT(8) +#define SPRD_RTC_MIN_UPD_EN BIT(9) +#define SPRD_RTC_HOUR_UPD_EN BIT(10) +#define SPRD_RTC_DAY_UPD_EN BIT(11) +#define SPRD_RTC_ALMSEC_UPD_EN BIT(12) +#define SPRD_RTC_ALMMIN_UPD_EN BIT(13) +#define SPRD_RTC_ALMHOUR_UPD_EN BIT(14) +#define SPRD_RTC_ALMDAY_UPD_EN BIT(15) +#define SPRD_RTC_INT_MASK GENMASK(15, 0) + +#define SPRD_RTC_TIME_INT_MASK \ + (SPRD_RTC_SEC_UPD_EN | SPRD_RTC_MIN_UPD_EN | \ + SPRD_RTC_HOUR_UPD_EN | SPRD_RTC_DAY_UPD_EN) + +#define SPRD_RTC_ALMTIME_INT_MASK \ + (SPRD_RTC_ALMSEC_UPD_EN | SPRD_RTC_ALMMIN_UPD_EN | \ + SPRD_RTC_ALMHOUR_UPD_EN | SPRD_RTC_ALMDAY_UPD_EN) + +#define SPRD_RTC_ALM_INT_MASK \ + (SPRD_RTC_SEC_EN | SPRD_RTC_MIN_EN | \ + SPRD_RTC_HOUR_EN | SPRD_RTC_DAY_EN | \ + SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN) + +/* second/minute/hour/day values mask definition */ +#define SPRD_RTC_SEC_MASK GENMASK(5, 0) +#define SPRD_RTC_MIN_MASK GENMASK(5, 0) +#define SPRD_RTC_HOUR_MASK GENMASK(4, 0) +#define SPRD_RTC_DAY_MASK GENMASK(15, 0) + +/* alarm lock definition for SPRD_RTC_SPG_UPD register */ +#define SPRD_RTC_ALMLOCK_MASK GENMASK(7, 0) +#define SPRD_RTC_ALM_UNLOCK 0xa5 +#define SPRD_RTC_ALM_LOCK (~SPRD_RTC_ALM_UNLOCK & \ + SPRD_RTC_ALMLOCK_MASK) + +/* SPG values definition for SPRD_RTC_SPG_UPD register */ +#define SPRD_RTC_POWEROFF_ALM_FLAG BIT(8) + +/* power control/status definition */ +#define SPRD_RTC_POWER_RESET_VALUE 0x96 +#define SPRD_RTC_POWER_STS_CLEAR GENMASK(7, 0) +#define SPRD_RTC_POWER_STS_SHIFT 8 +#define SPRD_RTC_POWER_STS_VALID \ + (~SPRD_RTC_POWER_RESET_VALUE << SPRD_RTC_POWER_STS_SHIFT) + +/* timeout of synchronizing time and alarm registers (us) */ +#define SPRD_RTC_POLL_TIMEOUT 200000 +#define SPRD_RTC_POLL_DELAY_US 20000 + +struct sprd_rtc { + struct rtc_device *rtc; + struct regmap *regmap; + struct device *dev; + u32 base; + int irq; + bool valid; +}; + +/* + * The Spreadtrum RTC controller has 3 groups registers, including time, normal + * alarm and auxiliary alarm. The time group registers are used to set RTC time, + * the normal alarm registers are used to set normal alarm, and the auxiliary + * alarm registers are used to set auxiliary alarm. Both alarm event and + * auxiliary alarm event can wake up system from deep sleep, but only alarm + * event can power up system from power down status. + */ +enum sprd_rtc_reg_types { + SPRD_RTC_TIME, + SPRD_RTC_ALARM, + SPRD_RTC_AUX_ALARM, +}; + +static int sprd_rtc_clear_alarm_ints(struct sprd_rtc *rtc) +{ + return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR, + SPRD_RTC_ALM_INT_MASK); +} + +static int sprd_rtc_lock_alarm(struct sprd_rtc *rtc, bool lock) +{ + int ret; + u32 val; + + ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_SPG_VALUE, &val); + if (ret) + return ret; + + val &= ~SPRD_RTC_ALMLOCK_MASK; + if (lock) + val |= SPRD_RTC_ALM_LOCK; + else + val |= SPRD_RTC_ALM_UNLOCK | SPRD_RTC_POWEROFF_ALM_FLAG; + + ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_SPG_UPD, val); + if (ret) + return ret; + + /* wait until the SPG value is updated successfully */ + ret = regmap_read_poll_timeout(rtc->regmap, + rtc->base + SPRD_RTC_INT_RAW_STS, val, + (val & SPRD_RTC_SPG_UPD_EN), + SPRD_RTC_POLL_DELAY_US, + SPRD_RTC_POLL_TIMEOUT); + if (ret) { + dev_err(rtc->dev, "failed to update SPG value:%d\n", ret); + return ret; + } + + return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR, + SPRD_RTC_SPG_UPD_EN); +} + +static int sprd_rtc_get_secs(struct sprd_rtc *rtc, enum sprd_rtc_reg_types type, + time64_t *secs) +{ + u32 sec_reg, min_reg, hour_reg, day_reg; + u32 val, sec, min, hour, day; + int ret; + + switch (type) { + case SPRD_RTC_TIME: + sec_reg = SPRD_RTC_SEC_CNT_VALUE; + min_reg = SPRD_RTC_MIN_CNT_VALUE; + hour_reg = SPRD_RTC_HOUR_CNT_VALUE; + day_reg = SPRD_RTC_DAY_CNT_VALUE; + break; + case SPRD_RTC_ALARM: + sec_reg = SPRD_RTC_SEC_ALM_VALUE; + min_reg = SPRD_RTC_MIN_ALM_VALUE; + hour_reg = SPRD_RTC_HOUR_ALM_VALUE; + day_reg = SPRD_RTC_DAY_ALM_VALUE; + break; + case SPRD_RTC_AUX_ALARM: + sec_reg = SPRD_RTC_SEC_AUXALM_UPD; + min_reg = SPRD_RTC_MIN_AUXALM_UPD; + hour_reg = SPRD_RTC_HOUR_AUXALM_UPD; + day_reg = SPRD_RTC_DAY_AUXALM_UPD; + break; + default: + return -EINVAL; + } + + ret = regmap_read(rtc->regmap, rtc->base + sec_reg, &val); + if (ret) + return ret; + + sec = val & SPRD_RTC_SEC_MASK; + + ret = regmap_read(rtc->regmap, rtc->base + min_reg, &val); + if (ret) + return ret; + + min = val & SPRD_RTC_MIN_MASK; + + ret = regmap_read(rtc->regmap, rtc->base + hour_reg, &val); + if (ret) + return ret; + + hour = val & SPRD_RTC_HOUR_MASK; + + ret = regmap_read(rtc->regmap, rtc->base + day_reg, &val); + if (ret) + return ret; + + day = val & SPRD_RTC_DAY_MASK; + *secs = (((time64_t)(day * 24) + hour) * 60 + min) * 60 + sec; + return 0; +} + +static int sprd_rtc_set_secs(struct sprd_rtc *rtc, enum sprd_rtc_reg_types type, + time64_t secs) +{ + u32 sec_reg, min_reg, hour_reg, day_reg, sts_mask; + u32 sec, min, hour, day, val; + int ret, rem; + + /* convert seconds to RTC time format */ + day = div_s64_rem(secs, 86400, &rem); + hour = rem / 3600; + rem -= hour * 3600; + min = rem / 60; + sec = rem - min * 60; + + switch (type) { + case SPRD_RTC_TIME: + sec_reg = SPRD_RTC_SEC_CNT_UPD; + min_reg = SPRD_RTC_MIN_CNT_UPD; + hour_reg = SPRD_RTC_HOUR_CNT_UPD; + day_reg = SPRD_RTC_DAY_CNT_UPD; + sts_mask = SPRD_RTC_TIME_INT_MASK; + break; + case SPRD_RTC_ALARM: + sec_reg = SPRD_RTC_SEC_ALM_UPD; + min_reg = SPRD_RTC_MIN_ALM_UPD; + hour_reg = SPRD_RTC_HOUR_ALM_UPD; + day_reg = SPRD_RTC_DAY_ALM_UPD; + sts_mask = SPRD_RTC_ALMTIME_INT_MASK; + break; + case SPRD_RTC_AUX_ALARM: + sec_reg = SPRD_RTC_SEC_AUXALM_UPD; + min_reg = SPRD_RTC_MIN_AUXALM_UPD; + hour_reg = SPRD_RTC_HOUR_AUXALM_UPD; + day_reg = SPRD_RTC_DAY_AUXALM_UPD; + sts_mask = 0; + break; + default: + return -EINVAL; + } + + ret = regmap_write(rtc->regmap, rtc->base + sec_reg, sec); + if (ret) + return ret; + + ret = regmap_write(rtc->regmap, rtc->base + min_reg, min); + if (ret) + return ret; + + ret = regmap_write(rtc->regmap, rtc->base + hour_reg, hour); + if (ret) + return ret; + + ret = regmap_write(rtc->regmap, rtc->base + day_reg, day); + if (ret) + return ret; + + if (type == SPRD_RTC_AUX_ALARM) + return 0; + + /* + * Since the time and normal alarm registers are put in always-power-on + * region supplied by VDDRTC, then these registers changing time will + * be very long, about 125ms. Thus here we should wait until all + * values are updated successfully. + */ + ret = regmap_read_poll_timeout(rtc->regmap, + rtc->base + SPRD_RTC_INT_RAW_STS, val, + ((val & sts_mask) == sts_mask), + SPRD_RTC_POLL_DELAY_US, + SPRD_RTC_POLL_TIMEOUT); + if (ret < 0) { + dev_err(rtc->dev, "set time/alarm values timeout\n"); + return ret; + } + + return regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR, + sts_mask); +} + +static int sprd_rtc_set_aux_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct sprd_rtc *rtc = dev_get_drvdata(dev); + time64_t secs = rtc_tm_to_time64(&alrm->time); + int ret; + + /* clear the auxiliary alarm interrupt status */ + ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR, + SPRD_RTC_AUXALM_EN); + if (ret) + return ret; + + ret = sprd_rtc_set_secs(rtc, SPRD_RTC_AUX_ALARM, secs); + if (ret) + return ret; + + if (alrm->enabled) { + ret = regmap_update_bits(rtc->regmap, + rtc->base + SPRD_RTC_INT_EN, + SPRD_RTC_AUXALM_EN, + SPRD_RTC_AUXALM_EN); + } else { + ret = regmap_update_bits(rtc->regmap, + rtc->base + SPRD_RTC_INT_EN, + SPRD_RTC_AUXALM_EN, 0); + } + + return ret; +} + +static int sprd_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct sprd_rtc *rtc = dev_get_drvdata(dev); + time64_t secs; + int ret; + + if (!rtc->valid) { + dev_warn(dev, "RTC values are invalid\n"); + return -EINVAL; + } + + ret = sprd_rtc_get_secs(rtc, SPRD_RTC_TIME, &secs); + if (ret) + return ret; + + rtc_time64_to_tm(secs, tm); + return 0; +} + +static int sprd_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct sprd_rtc *rtc = dev_get_drvdata(dev); + time64_t secs = rtc_tm_to_time64(tm); + int ret; + + ret = sprd_rtc_set_secs(rtc, SPRD_RTC_TIME, secs); + if (ret) + return ret; + + if (!rtc->valid) { + /* Clear RTC power status firstly */ + ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_PWR_CTRL, + SPRD_RTC_POWER_STS_CLEAR); + if (ret) + return ret; + + /* + * Set RTC power status to indicate now RTC has valid time + * values. + */ + ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_PWR_CTRL, + SPRD_RTC_POWER_STS_VALID); + if (ret) + return ret; + + rtc->valid = true; + } + + return 0; +} + +static int sprd_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct sprd_rtc *rtc = dev_get_drvdata(dev); + time64_t secs; + int ret; + u32 val; + + /* + * The RTC core checks to see if there is an alarm already set in RTC + * hardware, and we always read the normal alarm at this time. + */ + ret = sprd_rtc_get_secs(rtc, SPRD_RTC_ALARM, &secs); + if (ret) + return ret; + + rtc_time64_to_tm(secs, &alrm->time); + + ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_EN, &val); + if (ret) + return ret; + + alrm->enabled = !!(val & SPRD_RTC_ALARM_EN); + + ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_INT_RAW_STS, &val); + if (ret) + return ret; + + alrm->pending = !!(val & SPRD_RTC_ALARM_EN); + return 0; +} + +static int sprd_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct sprd_rtc *rtc = dev_get_drvdata(dev); + time64_t secs = rtc_tm_to_time64(&alrm->time); + struct rtc_time aie_time = + rtc_ktime_to_tm(rtc->rtc->aie_timer.node.expires); + int ret; + + /* + * We have 2 groups alarms: normal alarm and auxiliary alarm. Since + * both normal alarm event and auxiliary alarm event can wake up system + * from deep sleep, but only alarm event can power up system from power + * down status. Moreover we do not need to poll about 125ms when + * updating auxiliary alarm registers. Thus we usually set auxiliary + * alarm when wake up system from deep sleep, and for other scenarios, + * we should set normal alarm with polling status. + * + * So here we check if the alarm time is set by aie_timer, if yes, we + * should set normal alarm, if not, we should set auxiliary alarm which + * means it is just a wake event. + */ + if (!rtc->rtc->aie_timer.enabled || rtc_tm_sub(&aie_time, &alrm->time)) + return sprd_rtc_set_aux_alarm(dev, alrm); + + /* clear the alarm interrupt status firstly */ + ret = regmap_write(rtc->regmap, rtc->base + SPRD_RTC_INT_CLR, + SPRD_RTC_ALARM_EN); + if (ret) + return ret; + + ret = sprd_rtc_set_secs(rtc, SPRD_RTC_ALARM, secs); + if (ret) + return ret; + + if (alrm->enabled) { + ret = regmap_update_bits(rtc->regmap, + rtc->base + SPRD_RTC_INT_EN, + SPRD_RTC_ALARM_EN, + SPRD_RTC_ALARM_EN); + if (ret) + return ret; + + /* unlock the alarm to enable the alarm function. */ + ret = sprd_rtc_lock_alarm(rtc, false); + } else { + regmap_update_bits(rtc->regmap, + rtc->base + SPRD_RTC_INT_EN, + SPRD_RTC_ALARM_EN, 0); + + /* + * Lock the alarm function in case fake alarm event will power + * up systems. + */ + ret = sprd_rtc_lock_alarm(rtc, true); + } + + return ret; +} + +static int sprd_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct sprd_rtc *rtc = dev_get_drvdata(dev); + int ret; + + if (enabled) { + ret = regmap_update_bits(rtc->regmap, + rtc->base + SPRD_RTC_INT_EN, + SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN, + SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN); + if (ret) + return ret; + + ret = sprd_rtc_lock_alarm(rtc, false); + } else { + regmap_update_bits(rtc->regmap, rtc->base + SPRD_RTC_INT_EN, + SPRD_RTC_ALARM_EN | SPRD_RTC_AUXALM_EN, 0); + + ret = sprd_rtc_lock_alarm(rtc, true); + } + + return ret; +} + +static const struct rtc_class_ops sprd_rtc_ops = { + .read_time = sprd_rtc_read_time, + .set_time = sprd_rtc_set_time, + .read_alarm = sprd_rtc_read_alarm, + .set_alarm = sprd_rtc_set_alarm, + .alarm_irq_enable = sprd_rtc_alarm_irq_enable, +}; + +static irqreturn_t sprd_rtc_handler(int irq, void *dev_id) +{ + struct sprd_rtc *rtc = dev_id; + int ret; + + ret = sprd_rtc_clear_alarm_ints(rtc); + if (ret) + return IRQ_RETVAL(ret); + + rtc_update_irq(rtc->rtc, 1, RTC_AF | RTC_IRQF); + return IRQ_HANDLED; +} + +static int sprd_rtc_check_power_down(struct sprd_rtc *rtc) +{ + u32 val; + int ret; + + ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_PWR_STS, &val); + if (ret) + return ret; + + /* + * If the RTC power status value is SPRD_RTC_POWER_RESET_VALUE, which + * means the RTC has been powered down, so the RTC time values are + * invalid. + */ + rtc->valid = val != SPRD_RTC_POWER_RESET_VALUE; + return 0; +} + +static int sprd_rtc_check_alarm_int(struct sprd_rtc *rtc) +{ + u32 val; + int ret; + + ret = regmap_read(rtc->regmap, rtc->base + SPRD_RTC_SPG_VALUE, &val); + if (ret) + return ret; + + /* + * The SPRD_RTC_INT_EN register is not put in always-power-on region + * supplied by VDDRTC, so we should check if we need enable the alarm + * interrupt when system booting. + * + * If we have set SPRD_RTC_POWEROFF_ALM_FLAG which is saved in + * always-power-on region, that means we have set one alarm last time, + * so we should enable the alarm interrupt to help RTC core to see if + * there is an alarm already set in RTC hardware. + */ + if (!(val & SPRD_RTC_POWEROFF_ALM_FLAG)) + return 0; + + return regmap_update_bits(rtc->regmap, rtc->base + SPRD_RTC_INT_EN, + SPRD_RTC_ALARM_EN, SPRD_RTC_ALARM_EN); +} + +static int sprd_rtc_probe(struct platform_device *pdev) +{ + struct device_node *node = pdev->dev.of_node; + struct sprd_rtc *rtc; + int ret; + + rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); + if (!rtc) + return -ENOMEM; + + rtc->regmap = dev_get_regmap(pdev->dev.parent, NULL); + if (!rtc->regmap) + return -ENODEV; + + ret = of_property_read_u32(node, "reg", &rtc->base); + if (ret) { + dev_err(&pdev->dev, "failed to get RTC base address\n"); + return ret; + } + + rtc->irq = platform_get_irq(pdev, 0); + if (rtc->irq < 0) + return rtc->irq; + + rtc->rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(rtc->rtc)) + return PTR_ERR(rtc->rtc); + + rtc->dev = &pdev->dev; + platform_set_drvdata(pdev, rtc); + + /* check if we need set the alarm interrupt */ + ret = sprd_rtc_check_alarm_int(rtc); + if (ret) { + dev_err(&pdev->dev, "failed to check RTC alarm interrupt\n"); + return ret; + } + + /* check if RTC time values are valid */ + ret = sprd_rtc_check_power_down(rtc); + if (ret) { + dev_err(&pdev->dev, "failed to check RTC time values\n"); + return ret; + } + + ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL, + sprd_rtc_handler, + IRQF_ONESHOT | IRQF_EARLY_RESUME, + pdev->name, rtc); + if (ret < 0) { + dev_err(&pdev->dev, "failed to request RTC irq\n"); + return ret; + } + + device_init_wakeup(&pdev->dev, 1); + + rtc->rtc->ops = &sprd_rtc_ops; + rtc->rtc->range_min = 0; + rtc->rtc->range_max = 5662310399LL; + ret = devm_rtc_register_device(rtc->rtc); + if (ret) { + device_init_wakeup(&pdev->dev, 0); + return ret; + } + + return 0; +} + +static const struct of_device_id sprd_rtc_of_match[] = { + { .compatible = "sprd,sc2731-rtc", }, + { }, +}; +MODULE_DEVICE_TABLE(of, sprd_rtc_of_match); + +static struct platform_driver sprd_rtc_driver = { + .driver = { + .name = "sprd-rtc", + .of_match_table = sprd_rtc_of_match, + }, + .probe = sprd_rtc_probe, +}; +module_platform_driver(sprd_rtc_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Spreadtrum RTC Device Driver"); +MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>"); |