diff options
Diffstat (limited to 'drivers/rtc/rtc-rx8111.c')
| -rw-r--r-- | drivers/rtc/rtc-rx8111.c | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-rx8111.c b/drivers/rtc/rtc-rx8111.c new file mode 100644 index 0000000000..8450d9f0b5 --- /dev/null +++ b/drivers/rtc/rtc-rx8111.c @@ -0,0 +1,368 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for Epson RX8111 RTC. + * + * Copyright (C) 2023 Axis Communications AB + */ + +#include <linux/bcd.h> +#include <linux/bitfield.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/regmap.h> + +#include <linux/rtc.h> + +#define RX8111_REG_SEC 0x10 /* Second counter. */ +#define RX8111_REG_MIN 0x11 /* Minute counter */ +#define RX8111_REG_HOUR 0x12 /* Hour counter. */ +#define RX8111_REG_WEEK 0x13 /* Week day counter. */ +#define RX8111_REG_DAY 0x14 /* Month day counter. */ +#define RX8111_REG_MONTH 0x15 /* Month counter. */ +#define RX8111_REG_YEAR 0x16 /* Year counter. */ + +#define RX8111_REG_ALARM_MIN 0x17 /* Alarm minute. */ +#define RX8111_REG_ALARM_HOUR 0x18 /* Alarm hour. */ +#define RX8111_REG_ALARM_WEEK_DAY 0x19 /* Alarm week or month day. */ + +#define RX8111_REG_TIMER_COUNTER0 0x1a /* Timer counter LSB. */ +#define RX8111_REG_TIMER_COUNTER1 0x1b /* Timer counter. */ +#define RX8111_REG_TIMER_COUNTER2 0x1c /* Timer counter MSB. */ + +#define RX8111_REG_EXT 0x1d /* Extension register. */ +#define RX8111_REG_FLAG 0x1e /* Flag register. */ +#define RX8111_REG_CTRL 0x1f /* Control register. */ + +#define RX8111_REG_TS_1_1000_SEC 0x20 /* Timestamp 256 or 512 Hz . */ +#define RX8111_REG_TS_1_100_SEC 0x21 /* Timestamp 1 - 128 Hz. */ +#define RX8111_REG_TS_SEC 0x22 /* Timestamp second. */ +#define RX8111_REG_TS_MIN 0x23 /* Timestamp minute. */ +#define RX8111_REG_TS_HOUR 0x24 /* Timestamp hour. */ +#define RX8111_REG_TS_WEEK 0x25 /* Timestamp week day. */ +#define RX8111_REG_TS_DAY 0x26 /* Timestamp month day. */ +#define RX8111_REG_TS_MONTH 0x27 /* Timestamp month. */ +#define RX8111_REG_TS_YEAR 0x28 /* Timestamp year. */ +#define RX8111_REG_TS_STATUS 0x29 /* Timestamp status. */ + +#define RX8111_REG_EVIN_SETTING 0x2b /* Timestamp trigger setting. */ +#define RX8111_REG_ALARM_SEC 0x2c /* Alarm second. */ +#define RX8111_REG_TIMER_CTRL 0x2d /* Timer control. */ +#define RX8111_REG_TS_CTRL0 0x2e /* Timestamp control 0. */ +#define RX8111_REG_CMD_TRIGGER 0x2f /* Timestamp trigger. */ +#define RX8111_REG_PWR_SWITCH_CTRL 0x32 /* Power switch control. */ +#define RX8111_REG_STATUS_MON 0x33 /* Status monitor. */ +#define RX8111_REG_TS_CTRL1 0x34 /* Timestamp control 1. */ +#define RX8111_REG_TS_CTRL2 0x35 /* Timestamp control 2. */ +#define RX8111_REG_TS_CTRL3 0x36 /* Timestamp control 3. */ + +#define RX8111_FLAG_XST_BIT BIT(0) +#define RX8111_FLAG_VLF_BIT BIT(1) + +#define RX8111_TIME_BUF_SZ (RX8111_REG_YEAR - RX8111_REG_SEC + 1) + +enum rx8111_regfield { + /* RX8111_REG_EXT. */ + RX8111_REGF_TSEL0, + RX8111_REGF_TSEL1, + RX8111_REGF_ETS, + RX8111_REGF_WADA, + RX8111_REGF_TE, + RX8111_REGF_USEL, + RX8111_REGF_FSEL0, + RX8111_REGF_FSEL1, + + /* RX8111_REG_FLAG. */ + RX8111_REGF_XST, + RX8111_REGF_VLF, + RX8111_REGF_EVF, + RX8111_REGF_AF, + RX8111_REGF_TF, + RX8111_REGF_UF, + RX8111_REGF_POR, + + /* RX8111_REG_CTRL. */ + RX8111_REGF_STOP, + RX8111_REGF_EIE, + RX8111_REGF_AIE, + RX8111_REGF_TIE, + RX8111_REGF_UIE, + + /* RX8111_REG_PWR_SWITCH_CTRL. */ + RX8111_REGF_SMPT0, + RX8111_REGF_SMPT1, + RX8111_REGF_SWSEL0, + RX8111_REGF_SWSEL1, + RX8111_REGF_INIEN, + RX8111_REGF_CHGEN, + + /* RX8111_REG_STATUS_MON. */ + RX8111_REGF_VLOW, + + /* Sentinel value. */ + RX8111_REGF_MAX +}; + +static const struct reg_field rx8111_regfields[] = { + [RX8111_REGF_TSEL0] = REG_FIELD(RX8111_REG_EXT, 0, 0), + [RX8111_REGF_TSEL1] = REG_FIELD(RX8111_REG_EXT, 1, 1), + [RX8111_REGF_ETS] = REG_FIELD(RX8111_REG_EXT, 2, 2), + [RX8111_REGF_WADA] = REG_FIELD(RX8111_REG_EXT, 3, 3), + [RX8111_REGF_TE] = REG_FIELD(RX8111_REG_EXT, 4, 4), + [RX8111_REGF_USEL] = REG_FIELD(RX8111_REG_EXT, 5, 5), + [RX8111_REGF_FSEL0] = REG_FIELD(RX8111_REG_EXT, 6, 6), + [RX8111_REGF_FSEL1] = REG_FIELD(RX8111_REG_EXT, 7, 7), + + [RX8111_REGF_XST] = REG_FIELD(RX8111_REG_FLAG, 0, 0), + [RX8111_REGF_VLF] = REG_FIELD(RX8111_REG_FLAG, 1, 1), + [RX8111_REGF_EVF] = REG_FIELD(RX8111_REG_FLAG, 2, 2), + [RX8111_REGF_AF] = REG_FIELD(RX8111_REG_FLAG, 3, 3), + [RX8111_REGF_TF] = REG_FIELD(RX8111_REG_FLAG, 4, 4), + [RX8111_REGF_UF] = REG_FIELD(RX8111_REG_FLAG, 5, 5), + [RX8111_REGF_POR] = REG_FIELD(RX8111_REG_FLAG, 7, 7), + + [RX8111_REGF_STOP] = REG_FIELD(RX8111_REG_CTRL, 0, 0), + [RX8111_REGF_EIE] = REG_FIELD(RX8111_REG_CTRL, 2, 2), + [RX8111_REGF_AIE] = REG_FIELD(RX8111_REG_CTRL, 3, 3), + [RX8111_REGF_TIE] = REG_FIELD(RX8111_REG_CTRL, 4, 4), + [RX8111_REGF_UIE] = REG_FIELD(RX8111_REG_CTRL, 5, 5), + + [RX8111_REGF_SMPT0] = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 0, 0), + [RX8111_REGF_SMPT1] = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 1, 1), + [RX8111_REGF_SWSEL0] = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 2, 2), + [RX8111_REGF_SWSEL1] = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 3, 3), + [RX8111_REGF_INIEN] = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 6, 6), + [RX8111_REGF_CHGEN] = REG_FIELD(RX8111_REG_PWR_SWITCH_CTRL, 7, 7), + + [RX8111_REGF_VLOW] = REG_FIELD(RX8111_REG_STATUS_MON, 1, 1), +}; + +static const struct regmap_config rx8111_regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = RX8111_REG_TS_CTRL3, +}; + +struct rx8111_data { + struct regmap *regmap; + struct regmap_field *regfields[RX8111_REGF_MAX]; + struct device *dev; + struct rtc_device *rtc; +}; + +static int rx8111_read_vl_flag(struct rx8111_data *data, unsigned int *vlval) +{ + int ret; + + ret = regmap_field_read(data->regfields[RX8111_REGF_VLF], vlval); + if (ret) + dev_dbg(data->dev, "Could not read VL flag (%d)", ret); + + return ret; +} + +static int rx8111_read_time(struct device *dev, struct rtc_time *tm) +{ + struct rx8111_data *data = dev_get_drvdata(dev); + u8 buf[RX8111_TIME_BUF_SZ]; + unsigned int regval; + int ret; + + /* Check status. */ + ret = regmap_read(data->regmap, RX8111_REG_FLAG, ®val); + if (ret) { + dev_dbg(data->dev, "Could not read flag register (%d)\n", ret); + return ret; + } + + if (FIELD_GET(RX8111_FLAG_XST_BIT, regval)) { + dev_dbg(data->dev, + "Crystal oscillation stopped, time is not reliable\n"); + return -EINVAL; + } + + if (FIELD_GET(RX8111_FLAG_VLF_BIT, regval)) { + dev_dbg(data->dev, + "Low voltage detected, time is not reliable\n"); + return -EINVAL; + } + + ret = regmap_field_read(data->regfields[RX8111_REGF_STOP], ®val); + if (ret) { + dev_dbg(data->dev, "Could not read clock status (%d)\n", ret); + return ret; + } + + if (regval) { + dev_dbg(data->dev, "Clock stopped, time is not reliable\n"); + return -EINVAL; + } + + /* Read time. */ + ret = regmap_bulk_read(data->regmap, RX8111_REG_SEC, buf, + ARRAY_SIZE(buf)); + if (ret) { + dev_dbg(data->dev, "Could not bulk read time (%d)\n", ret); + return ret; + } + + tm->tm_sec = bcd2bin(buf[0]); + tm->tm_min = bcd2bin(buf[1]); + tm->tm_hour = bcd2bin(buf[2]); + tm->tm_wday = ffs(buf[3]) - 1; + tm->tm_mday = bcd2bin(buf[4]); + tm->tm_mon = bcd2bin(buf[5]) - 1; + tm->tm_year = bcd2bin(buf[6]) + 100; + + return 0; +} + +static int rx8111_set_time(struct device *dev, struct rtc_time *tm) +{ + struct rx8111_data *data = dev_get_drvdata(dev); + u8 buf[RX8111_TIME_BUF_SZ]; + int ret; + + buf[0] = bin2bcd(tm->tm_sec); + buf[1] = bin2bcd(tm->tm_min); + buf[2] = bin2bcd(tm->tm_hour); + buf[3] = BIT(tm->tm_wday); + buf[4] = bin2bcd(tm->tm_mday); + buf[5] = bin2bcd(tm->tm_mon + 1); + buf[6] = bin2bcd(tm->tm_year - 100); + + ret = regmap_clear_bits(data->regmap, RX8111_REG_FLAG, + RX8111_FLAG_XST_BIT | RX8111_FLAG_VLF_BIT); + if (ret) + return ret; + + /* Stop the clock. */ + ret = regmap_field_write(data->regfields[RX8111_REGF_STOP], 1); + if (ret) { + dev_dbg(data->dev, "Could not stop the clock (%d)\n", ret); + return ret; + } + + /* Set the time. */ + ret = regmap_bulk_write(data->regmap, RX8111_REG_SEC, buf, + ARRAY_SIZE(buf)); + if (ret) { + dev_dbg(data->dev, "Could not bulk write time (%d)\n", ret); + + /* + * We don't bother with trying to start the clock again. We + * check for this in rx8111_read_time() (and thus force user to + * call rx8111_set_time() to try again). + */ + return ret; + } + + /* Start the clock. */ + ret = regmap_field_write(data->regfields[RX8111_REGF_STOP], 0); + if (ret) { + dev_dbg(data->dev, "Could not start the clock (%d)\n", ret); + return ret; + } + + return 0; +} + +static int rx8111_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) +{ + struct rx8111_data *data = dev_get_drvdata(dev); + unsigned int regval; + unsigned int vlval; + int ret; + + switch (cmd) { + case RTC_VL_READ: + ret = rx8111_read_vl_flag(data, ®val); + if (ret) + return ret; + + vlval = regval ? RTC_VL_DATA_INVALID : 0; + + ret = regmap_field_read(data->regfields[RX8111_REGF_VLOW], + ®val); + if (ret) + return ret; + + vlval |= regval ? RTC_VL_BACKUP_LOW : 0; + + return put_user(vlval, (typeof(vlval) __user *)arg); + default: + return -ENOIOCTLCMD; + } +} + +static const struct rtc_class_ops rx8111_rtc_ops = { + .read_time = rx8111_read_time, + .set_time = rx8111_set_time, + .ioctl = rx8111_ioctl, +}; + +static int rx8111_probe(struct i2c_client *client) +{ + struct rx8111_data *data; + struct rtc_device *rtc; + size_t i; + + data = devm_kmalloc(&client->dev, sizeof(*data), GFP_KERNEL); + if (!data) { + dev_dbg(&client->dev, "Could not allocate device data\n"); + return -ENOMEM; + } + + data->dev = &client->dev; + dev_set_drvdata(data->dev, data); + + data->regmap = devm_regmap_init_i2c(client, &rx8111_regmap_config); + if (IS_ERR(data->regmap)) { + dev_dbg(data->dev, "Could not initialize regmap\n"); + return PTR_ERR(data->regmap); + } + + for (i = 0; i < RX8111_REGF_MAX; ++i) { + data->regfields[i] = devm_regmap_field_alloc( + data->dev, data->regmap, rx8111_regfields[i]); + if (IS_ERR(data->regfields[i])) { + dev_dbg(data->dev, + "Could not allocate register field %zu\n", i); + return PTR_ERR(data->regfields[i]); + } + } + + rtc = devm_rtc_allocate_device(data->dev); + if (IS_ERR(rtc)) { + dev_dbg(data->dev, "Could not allocate rtc device\n"); + return PTR_ERR(rtc); + } + + rtc->ops = &rx8111_rtc_ops; + rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; + rtc->range_max = RTC_TIMESTAMP_END_2099; + + clear_bit(RTC_FEATURE_ALARM, rtc->features); + + return devm_rtc_register_device(rtc); +} + +static const struct of_device_id rx8111_of_match[] = { + { + .compatible = "epson,rx8111", + }, + {} +}; +MODULE_DEVICE_TABLE(of, rx8111_of_match); + +static struct i2c_driver rx8111_driver = { + .driver = { + .name = "rtc-rx8111", + .of_match_table = rx8111_of_match, + }, + .probe = rx8111_probe, +}; +module_i2c_driver(rx8111_driver); + +MODULE_AUTHOR("Waqar Hameed <waqar.hameed@axis.com>"); +MODULE_DESCRIPTION("Epson RX8111 RTC driver"); +MODULE_LICENSE("GPL"); |