diff options
Diffstat (limited to 'drivers/rtc/rtc-lp8788.c')
| -rw-r--r-- | drivers/rtc/rtc-lp8788.c | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-lp8788.c b/drivers/rtc/rtc-lp8788.c new file mode 100644 index 000000000..c0b8fbce1 --- /dev/null +++ b/drivers/rtc/rtc-lp8788.c @@ -0,0 +1,322 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * TI LP8788 MFD - rtc driver + * + * Copyright 2012 Texas Instruments + * + * Author: Milo(Woogyom) Kim <milo.kim@ti.com> + */ + +#include <linux/err.h> +#include <linux/irqdomain.h> +#include <linux/mfd/lp8788.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/rtc.h> +#include <linux/slab.h> + +/* register address */ +#define LP8788_INTEN_3 0x05 +#define LP8788_RTC_UNLOCK 0x64 +#define LP8788_RTC_SEC 0x70 +#define LP8788_ALM1_SEC 0x77 +#define LP8788_ALM1_EN 0x7D +#define LP8788_ALM2_SEC 0x7E +#define LP8788_ALM2_EN 0x84 + +/* mask/shift bits */ +#define LP8788_INT_RTC_ALM1_M BIT(1) /* Addr 05h */ +#define LP8788_INT_RTC_ALM1_S 1 +#define LP8788_INT_RTC_ALM2_M BIT(2) /* Addr 05h */ +#define LP8788_INT_RTC_ALM2_S 2 +#define LP8788_ALM_EN_M BIT(7) /* Addr 7Dh or 84h */ +#define LP8788_ALM_EN_S 7 + +#define DEFAULT_ALARM_SEL LP8788_ALARM_1 +#define LP8788_MONTH_OFFSET 1 +#define LP8788_BASE_YEAR 2000 +#define MAX_WDAY_BITS 7 +#define LP8788_WDAY_SET 1 +#define RTC_UNLOCK 0x1 +#define RTC_LATCH 0x2 +#define ALARM_IRQ_FLAG (RTC_IRQF | RTC_AF) + +enum lp8788_time { + LPTIME_SEC, + LPTIME_MIN, + LPTIME_HOUR, + LPTIME_MDAY, + LPTIME_MON, + LPTIME_YEAR, + LPTIME_WDAY, + LPTIME_MAX, +}; + +struct lp8788_rtc { + struct lp8788 *lp; + struct rtc_device *rdev; + enum lp8788_alarm_sel alarm; + int irq; +}; + +static const u8 addr_alarm_sec[LP8788_ALARM_MAX] = { + LP8788_ALM1_SEC, + LP8788_ALM2_SEC, +}; + +static const u8 addr_alarm_en[LP8788_ALARM_MAX] = { + LP8788_ALM1_EN, + LP8788_ALM2_EN, +}; + +static const u8 mask_alarm_en[LP8788_ALARM_MAX] = { + LP8788_INT_RTC_ALM1_M, + LP8788_INT_RTC_ALM2_M, +}; + +static const u8 shift_alarm_en[LP8788_ALARM_MAX] = { + LP8788_INT_RTC_ALM1_S, + LP8788_INT_RTC_ALM2_S, +}; + +static int _to_tm_wday(u8 lp8788_wday) +{ + int i; + + if (lp8788_wday == 0) + return 0; + + /* lookup defined weekday from read register value */ + for (i = 0; i < MAX_WDAY_BITS; i++) { + if ((lp8788_wday >> i) == LP8788_WDAY_SET) + break; + } + + return i + 1; +} + +static inline int _to_lp8788_wday(int tm_wday) +{ + return LP8788_WDAY_SET << (tm_wday - 1); +} + +static void lp8788_rtc_unlock(struct lp8788 *lp) +{ + lp8788_write_byte(lp, LP8788_RTC_UNLOCK, RTC_UNLOCK); + lp8788_write_byte(lp, LP8788_RTC_UNLOCK, RTC_LATCH); +} + +static int lp8788_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct lp8788_rtc *rtc = dev_get_drvdata(dev); + struct lp8788 *lp = rtc->lp; + u8 data[LPTIME_MAX]; + int ret; + + lp8788_rtc_unlock(lp); + + ret = lp8788_read_multi_bytes(lp, LP8788_RTC_SEC, data, LPTIME_MAX); + if (ret) + return ret; + + tm->tm_sec = data[LPTIME_SEC]; + tm->tm_min = data[LPTIME_MIN]; + tm->tm_hour = data[LPTIME_HOUR]; + tm->tm_mday = data[LPTIME_MDAY]; + tm->tm_mon = data[LPTIME_MON] - LP8788_MONTH_OFFSET; + tm->tm_year = data[LPTIME_YEAR] + LP8788_BASE_YEAR - 1900; + tm->tm_wday = _to_tm_wday(data[LPTIME_WDAY]); + + return 0; +} + +static int lp8788_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct lp8788_rtc *rtc = dev_get_drvdata(dev); + struct lp8788 *lp = rtc->lp; + u8 data[LPTIME_MAX - 1]; + int ret, i, year; + + year = tm->tm_year + 1900 - LP8788_BASE_YEAR; + if (year < 0) { + dev_err(lp->dev, "invalid year: %d\n", year); + return -EINVAL; + } + + /* because rtc weekday is a readonly register, do not update */ + data[LPTIME_SEC] = tm->tm_sec; + data[LPTIME_MIN] = tm->tm_min; + data[LPTIME_HOUR] = tm->tm_hour; + data[LPTIME_MDAY] = tm->tm_mday; + data[LPTIME_MON] = tm->tm_mon + LP8788_MONTH_OFFSET; + data[LPTIME_YEAR] = year; + + for (i = 0; i < ARRAY_SIZE(data); i++) { + ret = lp8788_write_byte(lp, LP8788_RTC_SEC + i, data[i]); + if (ret) + return ret; + } + + return 0; +} + +static int lp8788_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct lp8788_rtc *rtc = dev_get_drvdata(dev); + struct lp8788 *lp = rtc->lp; + struct rtc_time *tm = &alarm->time; + u8 addr, data[LPTIME_MAX]; + int ret; + + addr = addr_alarm_sec[rtc->alarm]; + ret = lp8788_read_multi_bytes(lp, addr, data, LPTIME_MAX); + if (ret) + return ret; + + tm->tm_sec = data[LPTIME_SEC]; + tm->tm_min = data[LPTIME_MIN]; + tm->tm_hour = data[LPTIME_HOUR]; + tm->tm_mday = data[LPTIME_MDAY]; + tm->tm_mon = data[LPTIME_MON] - LP8788_MONTH_OFFSET; + tm->tm_year = data[LPTIME_YEAR] + LP8788_BASE_YEAR - 1900; + tm->tm_wday = _to_tm_wday(data[LPTIME_WDAY]); + alarm->enabled = data[LPTIME_WDAY] & LP8788_ALM_EN_M; + + return 0; +} + +static int lp8788_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct lp8788_rtc *rtc = dev_get_drvdata(dev); + struct lp8788 *lp = rtc->lp; + struct rtc_time *tm = &alarm->time; + u8 addr, data[LPTIME_MAX]; + int ret, i, year; + + year = tm->tm_year + 1900 - LP8788_BASE_YEAR; + if (year < 0) { + dev_err(lp->dev, "invalid year: %d\n", year); + return -EINVAL; + } + + data[LPTIME_SEC] = tm->tm_sec; + data[LPTIME_MIN] = tm->tm_min; + data[LPTIME_HOUR] = tm->tm_hour; + data[LPTIME_MDAY] = tm->tm_mday; + data[LPTIME_MON] = tm->tm_mon + LP8788_MONTH_OFFSET; + data[LPTIME_YEAR] = year; + data[LPTIME_WDAY] = _to_lp8788_wday(tm->tm_wday); + + for (i = 0; i < ARRAY_SIZE(data); i++) { + addr = addr_alarm_sec[rtc->alarm] + i; + ret = lp8788_write_byte(lp, addr, data[i]); + if (ret) + return ret; + } + + alarm->enabled = 1; + addr = addr_alarm_en[rtc->alarm]; + + return lp8788_update_bits(lp, addr, LP8788_ALM_EN_M, + alarm->enabled << LP8788_ALM_EN_S); +} + +static int lp8788_alarm_irq_enable(struct device *dev, unsigned int enable) +{ + struct lp8788_rtc *rtc = dev_get_drvdata(dev); + struct lp8788 *lp = rtc->lp; + u8 mask, shift; + + if (!rtc->irq) + return -EIO; + + mask = mask_alarm_en[rtc->alarm]; + shift = shift_alarm_en[rtc->alarm]; + + return lp8788_update_bits(lp, LP8788_INTEN_3, mask, enable << shift); +} + +static const struct rtc_class_ops lp8788_rtc_ops = { + .read_time = lp8788_rtc_read_time, + .set_time = lp8788_rtc_set_time, + .read_alarm = lp8788_read_alarm, + .set_alarm = lp8788_set_alarm, + .alarm_irq_enable = lp8788_alarm_irq_enable, +}; + +static irqreturn_t lp8788_alarm_irq_handler(int irq, void *ptr) +{ + struct lp8788_rtc *rtc = ptr; + + rtc_update_irq(rtc->rdev, 1, ALARM_IRQ_FLAG); + return IRQ_HANDLED; +} + +static int lp8788_alarm_irq_register(struct platform_device *pdev, + struct lp8788_rtc *rtc) +{ + struct resource *r; + struct lp8788 *lp = rtc->lp; + struct irq_domain *irqdm = lp->irqdm; + int irq; + + rtc->irq = 0; + + /* even the alarm IRQ number is not specified, rtc time should work */ + r = platform_get_resource_byname(pdev, IORESOURCE_IRQ, LP8788_ALM_IRQ); + if (!r) + return 0; + + if (rtc->alarm == LP8788_ALARM_1) + irq = r->start; + else + irq = r->end; + + rtc->irq = irq_create_mapping(irqdm, irq); + + return devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL, + lp8788_alarm_irq_handler, + 0, LP8788_ALM_IRQ, rtc); +} + +static int lp8788_rtc_probe(struct platform_device *pdev) +{ + struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent); + struct lp8788_rtc *rtc; + struct device *dev = &pdev->dev; + + rtc = devm_kzalloc(dev, sizeof(struct lp8788_rtc), GFP_KERNEL); + if (!rtc) + return -ENOMEM; + + rtc->lp = lp; + rtc->alarm = lp->pdata ? lp->pdata->alarm_sel : DEFAULT_ALARM_SEL; + platform_set_drvdata(pdev, rtc); + + device_init_wakeup(dev, 1); + + rtc->rdev = devm_rtc_device_register(dev, "lp8788_rtc", + &lp8788_rtc_ops, THIS_MODULE); + if (IS_ERR(rtc->rdev)) { + dev_err(dev, "can not register rtc device\n"); + return PTR_ERR(rtc->rdev); + } + + if (lp8788_alarm_irq_register(pdev, rtc)) + dev_warn(lp->dev, "no rtc irq handler\n"); + + return 0; +} + +static struct platform_driver lp8788_rtc_driver = { + .probe = lp8788_rtc_probe, + .driver = { + .name = LP8788_DEV_RTC, + }, +}; +module_platform_driver(lp8788_rtc_driver); + +MODULE_DESCRIPTION("Texas Instruments LP8788 RTC Driver"); +MODULE_AUTHOR("Milo Kim"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:lp8788-rtc"); |