diff options
Diffstat (limited to 'drivers/rtc/rtc-bd70528.c')
| -rw-r--r-- | drivers/rtc/rtc-bd70528.c | 360 |
1 files changed, 360 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-bd70528.c b/drivers/rtc/rtc-bd70528.c new file mode 100644 index 000000000..59b627fc1 --- /dev/null +++ b/drivers/rtc/rtc-bd70528.c @@ -0,0 +1,360 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +// +// Copyright (C) 2018 ROHM Semiconductors +// +// RTC driver for ROHM BD71828 and BD71815 PMIC + +#include <linux/bcd.h> +#include <linux/mfd/rohm-bd71815.h> +#include <linux/mfd/rohm-bd71828.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/rtc.h> + +/* + * On BD71828 and BD71815 the ALM0 MASK is 14 bytes after the ALM0 + * block start + */ +#define BD718XX_ALM_EN_OFFSET 14 + +/* + * We read regs RTC_SEC => RTC_YEAR + * this struct is ordered according to chip registers. + * Keep it u8 only (or packed) to avoid padding issues. + */ +struct bd70528_rtc_day { + u8 sec; + u8 min; + u8 hour; +} __packed; + +struct bd70528_rtc_data { + struct bd70528_rtc_day time; + u8 week; + u8 day; + u8 month; + u8 year; +} __packed; + +struct bd71828_rtc_alm { + struct bd70528_rtc_data alm0; + struct bd70528_rtc_data alm1; + u8 alm_mask; + u8 alm1_mask; +} __packed; + +struct bd70528_rtc { + struct rohm_regmap_dev *parent; + struct regmap *regmap; + struct device *dev; + u8 reg_time_start; + u8 bd718xx_alm_block_start; +}; + +static inline void tmday2rtc(struct rtc_time *t, struct bd70528_rtc_day *d) +{ + d->sec &= ~BD70528_MASK_RTC_SEC; + d->min &= ~BD70528_MASK_RTC_MINUTE; + d->hour &= ~BD70528_MASK_RTC_HOUR; + d->sec |= bin2bcd(t->tm_sec); + d->min |= bin2bcd(t->tm_min); + d->hour |= bin2bcd(t->tm_hour); +} + +static inline void tm2rtc(struct rtc_time *t, struct bd70528_rtc_data *r) +{ + r->day &= ~BD70528_MASK_RTC_DAY; + r->week &= ~BD70528_MASK_RTC_WEEK; + r->month &= ~BD70528_MASK_RTC_MONTH; + /* + * PM and 24H bits are not used by Wake - thus we clear them + * here and not in tmday2rtc() which is also used by wake. + */ + r->time.hour &= ~(BD70528_MASK_RTC_HOUR_PM | BD70528_MASK_RTC_HOUR_24H); + + tmday2rtc(t, &r->time); + /* + * We do always set time in 24H mode. + */ + r->time.hour |= BD70528_MASK_RTC_HOUR_24H; + r->day |= bin2bcd(t->tm_mday); + r->week |= bin2bcd(t->tm_wday); + r->month |= bin2bcd(t->tm_mon + 1); + r->year = bin2bcd(t->tm_year - 100); +} + +static inline void rtc2tm(struct bd70528_rtc_data *r, struct rtc_time *t) +{ + t->tm_sec = bcd2bin(r->time.sec & BD70528_MASK_RTC_SEC); + t->tm_min = bcd2bin(r->time.min & BD70528_MASK_RTC_MINUTE); + t->tm_hour = bcd2bin(r->time.hour & BD70528_MASK_RTC_HOUR); + /* + * If RTC is in 12H mode, then bit BD70528_MASK_RTC_HOUR_PM + * is not BCD value but tells whether it is AM or PM + */ + if (!(r->time.hour & BD70528_MASK_RTC_HOUR_24H)) { + t->tm_hour %= 12; + if (r->time.hour & BD70528_MASK_RTC_HOUR_PM) + t->tm_hour += 12; + } + t->tm_mday = bcd2bin(r->day & BD70528_MASK_RTC_DAY); + t->tm_mon = bcd2bin(r->month & BD70528_MASK_RTC_MONTH) - 1; + t->tm_year = 100 + bcd2bin(r->year & BD70528_MASK_RTC_YEAR); + t->tm_wday = bcd2bin(r->week & BD70528_MASK_RTC_WEEK); +} + +static int bd71828_set_alarm(struct device *dev, struct rtc_wkalrm *a) +{ + int ret; + struct bd71828_rtc_alm alm; + struct bd70528_rtc *r = dev_get_drvdata(dev); + + ret = regmap_bulk_read(r->regmap, r->bd718xx_alm_block_start, &alm, + sizeof(alm)); + if (ret) { + dev_err(dev, "Failed to read alarm regs\n"); + return ret; + } + + tm2rtc(&a->time, &alm.alm0); + + if (!a->enabled) + alm.alm_mask &= ~BD70528_MASK_ALM_EN; + else + alm.alm_mask |= BD70528_MASK_ALM_EN; + + ret = regmap_bulk_write(r->regmap, r->bd718xx_alm_block_start, &alm, + sizeof(alm)); + if (ret) + dev_err(dev, "Failed to set alarm time\n"); + + return ret; + +} + +static int bd71828_read_alarm(struct device *dev, struct rtc_wkalrm *a) +{ + int ret; + struct bd71828_rtc_alm alm; + struct bd70528_rtc *r = dev_get_drvdata(dev); + + ret = regmap_bulk_read(r->regmap, r->bd718xx_alm_block_start, &alm, + sizeof(alm)); + if (ret) { + dev_err(dev, "Failed to read alarm regs\n"); + return ret; + } + + rtc2tm(&alm.alm0, &a->time); + a->time.tm_mday = -1; + a->time.tm_mon = -1; + a->time.tm_year = -1; + a->enabled = !!(alm.alm_mask & BD70528_MASK_ALM_EN); + a->pending = 0; + + return 0; +} + +static int bd71828_set_time(struct device *dev, struct rtc_time *t) +{ + int ret; + struct bd70528_rtc_data rtc_data; + struct bd70528_rtc *r = dev_get_drvdata(dev); + + ret = regmap_bulk_read(r->regmap, r->reg_time_start, &rtc_data, + sizeof(rtc_data)); + if (ret) { + dev_err(dev, "Failed to read RTC time registers\n"); + return ret; + } + tm2rtc(t, &rtc_data); + + ret = regmap_bulk_write(r->regmap, r->reg_time_start, &rtc_data, + sizeof(rtc_data)); + if (ret) + dev_err(dev, "Failed to set RTC time\n"); + + return ret; +} + +static int bd70528_get_time(struct device *dev, struct rtc_time *t) +{ + struct bd70528_rtc *r = dev_get_drvdata(dev); + struct bd70528_rtc_data rtc_data; + int ret; + + /* read the RTC date and time registers all at once */ + ret = regmap_bulk_read(r->regmap, r->reg_time_start, &rtc_data, + sizeof(rtc_data)); + if (ret) { + dev_err(dev, "Failed to read RTC time (err %d)\n", ret); + return ret; + } + + rtc2tm(&rtc_data, t); + + return 0; +} + +static int bd71828_alm_enable(struct device *dev, unsigned int enabled) +{ + int ret; + struct bd70528_rtc *r = dev_get_drvdata(dev); + unsigned int enableval = BD70528_MASK_ALM_EN; + + if (!enabled) + enableval = 0; + + ret = regmap_update_bits(r->regmap, r->bd718xx_alm_block_start + + BD718XX_ALM_EN_OFFSET, BD70528_MASK_ALM_EN, + enableval); + if (ret) + dev_err(dev, "Failed to change alarm state\n"); + + return ret; +} + +static const struct rtc_class_ops bd71828_rtc_ops = { + .read_time = bd70528_get_time, + .set_time = bd71828_set_time, + .read_alarm = bd71828_read_alarm, + .set_alarm = bd71828_set_alarm, + .alarm_irq_enable = bd71828_alm_enable, +}; + +static irqreturn_t alm_hndlr(int irq, void *data) +{ + struct rtc_device *rtc = data; + + rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF | RTC_PF); + return IRQ_HANDLED; +} + +static int bd70528_probe(struct platform_device *pdev) +{ + struct bd70528_rtc *bd_rtc; + const struct rtc_class_ops *rtc_ops; + const char *irq_name; + int ret; + struct rtc_device *rtc; + int irq; + unsigned int hr; + u8 hour_reg; + enum rohm_chip_type chip = platform_get_device_id(pdev)->driver_data; + + bd_rtc = devm_kzalloc(&pdev->dev, sizeof(*bd_rtc), GFP_KERNEL); + if (!bd_rtc) + return -ENOMEM; + + bd_rtc->regmap = dev_get_regmap(pdev->dev.parent, NULL); + if (!bd_rtc->regmap) { + dev_err(&pdev->dev, "No regmap\n"); + return -EINVAL; + } + + bd_rtc->dev = &pdev->dev; + rtc_ops = &bd71828_rtc_ops; + + switch (chip) { + case ROHM_CHIP_TYPE_BD71815: + irq_name = "bd71815-rtc-alm-0"; + bd_rtc->reg_time_start = BD71815_REG_RTC_START; + + /* + * See also BD718XX_ALM_EN_OFFSET: + * This works for BD71828 and BD71815 as they have same offset + * between ALM0 start and ALM0_MASK. If new ICs are to be + * added this requires proper check as ALM0_MASK is not located + * at the end of ALM0 block - but after all ALM blocks so if + * amount of ALMs differ the offset to enable/disable is likely + * to be incorrect and enable/disable must be given as own + * reg address here. + */ + bd_rtc->bd718xx_alm_block_start = BD71815_REG_RTC_ALM_START; + hour_reg = BD71815_REG_HOUR; + break; + case ROHM_CHIP_TYPE_BD71828: + irq_name = "bd71828-rtc-alm-0"; + bd_rtc->reg_time_start = BD71828_REG_RTC_START; + bd_rtc->bd718xx_alm_block_start = BD71828_REG_RTC_ALM_START; + hour_reg = BD71828_REG_RTC_HOUR; + break; + default: + dev_err(&pdev->dev, "Unknown chip\n"); + return -ENOENT; + } + + irq = platform_get_irq_byname(pdev, irq_name); + + if (irq < 0) + return irq; + + platform_set_drvdata(pdev, bd_rtc); + + ret = regmap_read(bd_rtc->regmap, hour_reg, &hr); + + if (ret) { + dev_err(&pdev->dev, "Failed to reag RTC clock\n"); + return ret; + } + + if (!(hr & BD70528_MASK_RTC_HOUR_24H)) { + struct rtc_time t; + + ret = rtc_ops->read_time(&pdev->dev, &t); + + if (!ret) + ret = rtc_ops->set_time(&pdev->dev, &t); + + if (ret) { + dev_err(&pdev->dev, + "Setting 24H clock for RTC failed\n"); + return ret; + } + } + + device_set_wakeup_capable(&pdev->dev, true); + device_wakeup_enable(&pdev->dev); + + rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(rtc)) { + dev_err(&pdev->dev, "RTC device creation failed\n"); + return PTR_ERR(rtc); + } + + rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; + rtc->range_max = RTC_TIMESTAMP_END_2099; + rtc->ops = rtc_ops; + + /* Request alarm IRQ prior to registerig the RTC */ + ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, &alm_hndlr, + IRQF_ONESHOT, "bd70528-rtc", rtc); + if (ret) + return ret; + + return devm_rtc_register_device(rtc); +} + +static const struct platform_device_id bd718x7_rtc_id[] = { + { "bd71828-rtc", ROHM_CHIP_TYPE_BD71828 }, + { "bd71815-rtc", ROHM_CHIP_TYPE_BD71815 }, + { }, +}; +MODULE_DEVICE_TABLE(platform, bd718x7_rtc_id); + +static struct platform_driver bd70528_rtc = { + .driver = { + .name = "bd70528-rtc" + }, + .probe = bd70528_probe, + .id_table = bd718x7_rtc_id, +}; + +module_platform_driver(bd70528_rtc); + +MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>"); +MODULE_DESCRIPTION("ROHM BD71828 and BD71815 PMIC RTC driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:bd70528-rtc"); |