diff options
Diffstat (limited to 'drivers/rtc/rtc-rv3028.c')
| -rw-r--r-- | drivers/rtc/rtc-rv3028.c | 923 |
1 files changed, 923 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-rv3028.c b/drivers/rtc/rtc-rv3028.c new file mode 100644 index 000000000..fa226f0fe --- /dev/null +++ b/drivers/rtc/rtc-rv3028.c @@ -0,0 +1,923 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * RTC driver for the Micro Crystal RV3028 + * + * Copyright (C) 2019 Micro Crystal SA + * + * Alexandre Belloni <alexandre.belloni@bootlin.com> + * + */ + +#include <linux/clk-provider.h> +#include <linux/bcd.h> +#include <linux/bitops.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/log2.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/regmap.h> +#include <linux/rtc.h> + +#define RV3028_SEC 0x00 +#define RV3028_MIN 0x01 +#define RV3028_HOUR 0x02 +#define RV3028_WDAY 0x03 +#define RV3028_DAY 0x04 +#define RV3028_MONTH 0x05 +#define RV3028_YEAR 0x06 +#define RV3028_ALARM_MIN 0x07 +#define RV3028_ALARM_HOUR 0x08 +#define RV3028_ALARM_DAY 0x09 +#define RV3028_STATUS 0x0E +#define RV3028_CTRL1 0x0F +#define RV3028_CTRL2 0x10 +#define RV3028_EVT_CTRL 0x13 +#define RV3028_TS_COUNT 0x14 +#define RV3028_TS_SEC 0x15 +#define RV3028_RAM1 0x1F +#define RV3028_EEPROM_ADDR 0x25 +#define RV3028_EEPROM_DATA 0x26 +#define RV3028_EEPROM_CMD 0x27 +#define RV3028_CLKOUT 0x35 +#define RV3028_OFFSET 0x36 +#define RV3028_BACKUP 0x37 + +#define RV3028_STATUS_PORF BIT(0) +#define RV3028_STATUS_EVF BIT(1) +#define RV3028_STATUS_AF BIT(2) +#define RV3028_STATUS_TF BIT(3) +#define RV3028_STATUS_UF BIT(4) +#define RV3028_STATUS_BSF BIT(5) +#define RV3028_STATUS_CLKF BIT(6) +#define RV3028_STATUS_EEBUSY BIT(7) + +#define RV3028_CLKOUT_FD_MASK GENMASK(2, 0) +#define RV3028_CLKOUT_PORIE BIT(3) +#define RV3028_CLKOUT_CLKSY BIT(6) +#define RV3028_CLKOUT_CLKOE BIT(7) + +#define RV3028_CTRL1_EERD BIT(3) +#define RV3028_CTRL1_WADA BIT(5) + +#define RV3028_CTRL2_RESET BIT(0) +#define RV3028_CTRL2_12_24 BIT(1) +#define RV3028_CTRL2_EIE BIT(2) +#define RV3028_CTRL2_AIE BIT(3) +#define RV3028_CTRL2_TIE BIT(4) +#define RV3028_CTRL2_UIE BIT(5) +#define RV3028_CTRL2_TSE BIT(7) + +#define RV3028_EVT_CTRL_TSR BIT(2) + +#define RV3028_EEPROM_CMD_UPDATE 0x11 +#define RV3028_EEPROM_CMD_WRITE 0x21 +#define RV3028_EEPROM_CMD_READ 0x22 + +#define RV3028_EEBUSY_POLL 10000 +#define RV3028_EEBUSY_TIMEOUT 100000 + +#define RV3028_BACKUP_TCE BIT(5) +#define RV3028_BACKUP_TCR_MASK GENMASK(1,0) + +#define OFFSET_STEP_PPT 953674 + +enum rv3028_type { + rv_3028, +}; + +struct rv3028_data { + struct regmap *regmap; + struct rtc_device *rtc; + enum rv3028_type type; +#ifdef CONFIG_COMMON_CLK + struct clk_hw clkout_hw; +#endif +}; + +static u16 rv3028_trickle_resistors[] = {3000, 5000, 9000, 15000}; + +static ssize_t timestamp0_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent); + + regmap_update_bits(rv3028->regmap, RV3028_EVT_CTRL, RV3028_EVT_CTRL_TSR, + RV3028_EVT_CTRL_TSR); + + return count; +}; + +static ssize_t timestamp0_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent); + struct rtc_time tm; + int ret, count; + u8 date[6]; + + ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count); + if (ret) + return ret; + + if (!count) + return 0; + + ret = regmap_bulk_read(rv3028->regmap, RV3028_TS_SEC, date, + sizeof(date)); + if (ret) + return ret; + + tm.tm_sec = bcd2bin(date[0]); + tm.tm_min = bcd2bin(date[1]); + tm.tm_hour = bcd2bin(date[2]); + tm.tm_mday = bcd2bin(date[3]); + tm.tm_mon = bcd2bin(date[4]) - 1; + tm.tm_year = bcd2bin(date[5]) + 100; + + ret = rtc_valid_tm(&tm); + if (ret) + return ret; + + return sprintf(buf, "%llu\n", + (unsigned long long)rtc_tm_to_time64(&tm)); +}; + +static DEVICE_ATTR_RW(timestamp0); + +static ssize_t timestamp0_count_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct rv3028_data *rv3028 = dev_get_drvdata(dev->parent); + int ret, count; + + ret = regmap_read(rv3028->regmap, RV3028_TS_COUNT, &count); + if (ret) + return ret; + + return sprintf(buf, "%u\n", count); +}; + +static DEVICE_ATTR_RO(timestamp0_count); + +static struct attribute *rv3028_attrs[] = { + &dev_attr_timestamp0.attr, + &dev_attr_timestamp0_count.attr, + NULL +}; + +static const struct attribute_group rv3028_attr_group = { + .attrs = rv3028_attrs, +}; + +static int rv3028_exit_eerd(struct rv3028_data *rv3028, u32 eerd) +{ + if (eerd) + return 0; + + return regmap_update_bits(rv3028->regmap, RV3028_CTRL1, RV3028_CTRL1_EERD, 0); +} + +static int rv3028_enter_eerd(struct rv3028_data *rv3028, u32 *eerd) +{ + u32 ctrl1, status; + int ret; + + ret = regmap_read(rv3028->regmap, RV3028_CTRL1, &ctrl1); + if (ret) + return ret; + + *eerd = ctrl1 & RV3028_CTRL1_EERD; + if (*eerd) + return 0; + + ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL1, + RV3028_CTRL1_EERD, RV3028_CTRL1_EERD); + if (ret) + return ret; + + ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status, + !(status & RV3028_STATUS_EEBUSY), + RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT); + if (ret) { + rv3028_exit_eerd(rv3028, *eerd); + + return ret; + } + + return 0; +} + +static int rv3028_update_eeprom(struct rv3028_data *rv3028, u32 eerd) +{ + u32 status; + int ret; + + ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0); + if (ret) + goto exit_eerd; + + ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, RV3028_EEPROM_CMD_UPDATE); + if (ret) + goto exit_eerd; + + usleep_range(63000, RV3028_EEBUSY_TIMEOUT); + + ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status, + !(status & RV3028_STATUS_EEBUSY), + RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT); + +exit_eerd: + rv3028_exit_eerd(rv3028, eerd); + + return ret; +} + +static int rv3028_update_cfg(struct rv3028_data *rv3028, unsigned int reg, + unsigned int mask, unsigned int val) +{ + u32 eerd; + int ret; + + ret = rv3028_enter_eerd(rv3028, &eerd); + if (ret) + return ret; + + ret = regmap_update_bits(rv3028->regmap, reg, mask, val); + if (ret) { + rv3028_exit_eerd(rv3028, eerd); + return ret; + } + + return rv3028_update_eeprom(rv3028, eerd); +} + +static irqreturn_t rv3028_handle_irq(int irq, void *dev_id) +{ + struct rv3028_data *rv3028 = dev_id; + unsigned long events = 0; + u32 status = 0, ctrl = 0; + + if (regmap_read(rv3028->regmap, RV3028_STATUS, &status) < 0 || + status == 0) { + return IRQ_NONE; + } + + if (status & RV3028_STATUS_PORF) + dev_warn(&rv3028->rtc->dev, "Voltage low, data loss detected.\n"); + + if (status & RV3028_STATUS_TF) { + status |= RV3028_STATUS_TF; + ctrl |= RV3028_CTRL2_TIE; + events |= RTC_PF; + } + + if (status & RV3028_STATUS_AF) { + status |= RV3028_STATUS_AF; + ctrl |= RV3028_CTRL2_AIE; + events |= RTC_AF; + } + + if (status & RV3028_STATUS_UF) { + status |= RV3028_STATUS_UF; + ctrl |= RV3028_CTRL2_UIE; + events |= RTC_UF; + } + + if (events) { + rtc_update_irq(rv3028->rtc, 1, events); + regmap_update_bits(rv3028->regmap, RV3028_STATUS, status, 0); + regmap_update_bits(rv3028->regmap, RV3028_CTRL2, ctrl, 0); + } + + if (status & RV3028_STATUS_EVF) { + sysfs_notify(&rv3028->rtc->dev.kobj, NULL, + dev_attr_timestamp0.attr.name); + dev_warn(&rv3028->rtc->dev, "event detected"); + } + + return IRQ_HANDLED; +} + +static int rv3028_get_time(struct device *dev, struct rtc_time *tm) +{ + struct rv3028_data *rv3028 = dev_get_drvdata(dev); + u8 date[7]; + int ret, status; + + ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status); + if (ret < 0) + return ret; + + if (status & RV3028_STATUS_PORF) { + dev_warn(dev, "Voltage low, data is invalid.\n"); + return -EINVAL; + } + + ret = regmap_bulk_read(rv3028->regmap, RV3028_SEC, date, sizeof(date)); + if (ret) + return ret; + + tm->tm_sec = bcd2bin(date[RV3028_SEC] & 0x7f); + tm->tm_min = bcd2bin(date[RV3028_MIN] & 0x7f); + tm->tm_hour = bcd2bin(date[RV3028_HOUR] & 0x3f); + tm->tm_wday = ilog2(date[RV3028_WDAY] & 0x7f); + tm->tm_mday = bcd2bin(date[RV3028_DAY] & 0x3f); + tm->tm_mon = bcd2bin(date[RV3028_MONTH] & 0x1f) - 1; + tm->tm_year = bcd2bin(date[RV3028_YEAR]) + 100; + + return 0; +} + +static int rv3028_set_time(struct device *dev, struct rtc_time *tm) +{ + struct rv3028_data *rv3028 = dev_get_drvdata(dev); + u8 date[7]; + int ret; + + date[RV3028_SEC] = bin2bcd(tm->tm_sec); + date[RV3028_MIN] = bin2bcd(tm->tm_min); + date[RV3028_HOUR] = bin2bcd(tm->tm_hour); + date[RV3028_WDAY] = 1 << (tm->tm_wday); + date[RV3028_DAY] = bin2bcd(tm->tm_mday); + date[RV3028_MONTH] = bin2bcd(tm->tm_mon + 1); + date[RV3028_YEAR] = bin2bcd(tm->tm_year - 100); + + /* + * Writing to the Seconds register has the same effect as setting RESET + * bit to 1 + */ + ret = regmap_bulk_write(rv3028->regmap, RV3028_SEC, date, + sizeof(date)); + if (ret) + return ret; + + ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS, + RV3028_STATUS_PORF, 0); + + return ret; +} + +static int rv3028_get_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct rv3028_data *rv3028 = dev_get_drvdata(dev); + u8 alarmvals[3]; + int status, ctrl, ret; + + ret = regmap_bulk_read(rv3028->regmap, RV3028_ALARM_MIN, alarmvals, + sizeof(alarmvals)); + if (ret) + return ret; + + ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status); + if (ret < 0) + return ret; + + ret = regmap_read(rv3028->regmap, RV3028_CTRL2, &ctrl); + if (ret < 0) + return ret; + + alrm->time.tm_sec = 0; + alrm->time.tm_min = bcd2bin(alarmvals[0] & 0x7f); + alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f); + alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f); + + alrm->enabled = !!(ctrl & RV3028_CTRL2_AIE); + alrm->pending = (status & RV3028_STATUS_AF) && alrm->enabled; + + return 0; +} + +static int rv3028_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct rv3028_data *rv3028 = dev_get_drvdata(dev); + u8 alarmvals[3]; + u8 ctrl = 0; + int ret; + + /* The alarm has no seconds, round up to nearest minute */ + if (alrm->time.tm_sec) { + time64_t alarm_time = rtc_tm_to_time64(&alrm->time); + + alarm_time += 60 - alrm->time.tm_sec; + rtc_time64_to_tm(alarm_time, &alrm->time); + } + + ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2, + RV3028_CTRL2_AIE | RV3028_CTRL2_UIE, 0); + if (ret) + return ret; + + alarmvals[0] = bin2bcd(alrm->time.tm_min); + alarmvals[1] = bin2bcd(alrm->time.tm_hour); + alarmvals[2] = bin2bcd(alrm->time.tm_mday); + + ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS, + RV3028_STATUS_AF, 0); + if (ret) + return ret; + + ret = regmap_bulk_write(rv3028->regmap, RV3028_ALARM_MIN, alarmvals, + sizeof(alarmvals)); + if (ret) + return ret; + + if (alrm->enabled) { + if (rv3028->rtc->uie_rtctimer.enabled) + ctrl |= RV3028_CTRL2_UIE; + if (rv3028->rtc->aie_timer.enabled) + ctrl |= RV3028_CTRL2_AIE; + } + + ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2, + RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl); + + return ret; +} + +static int rv3028_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct rv3028_data *rv3028 = dev_get_drvdata(dev); + int ctrl = 0, ret; + + if (enabled) { + if (rv3028->rtc->uie_rtctimer.enabled) + ctrl |= RV3028_CTRL2_UIE; + if (rv3028->rtc->aie_timer.enabled) + ctrl |= RV3028_CTRL2_AIE; + } + + ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS, + RV3028_STATUS_AF | RV3028_STATUS_UF, 0); + if (ret) + return ret; + + ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2, + RV3028_CTRL2_UIE | RV3028_CTRL2_AIE, ctrl); + if (ret) + return ret; + + return 0; +} + +static int rv3028_read_offset(struct device *dev, long *offset) +{ + struct rv3028_data *rv3028 = dev_get_drvdata(dev); + int ret, value, steps; + + ret = regmap_read(rv3028->regmap, RV3028_OFFSET, &value); + if (ret < 0) + return ret; + + steps = sign_extend32(value << 1, 8); + + ret = regmap_read(rv3028->regmap, RV3028_BACKUP, &value); + if (ret < 0) + return ret; + + steps += value >> 7; + + *offset = DIV_ROUND_CLOSEST(steps * OFFSET_STEP_PPT, 1000); + + return 0; +} + +static int rv3028_set_offset(struct device *dev, long offset) +{ + struct rv3028_data *rv3028 = dev_get_drvdata(dev); + u32 eerd; + int ret; + + offset = clamp(offset, -244141L, 243187L) * 1000; + offset = DIV_ROUND_CLOSEST(offset, OFFSET_STEP_PPT); + + ret = rv3028_enter_eerd(rv3028, &eerd); + if (ret) + return ret; + + ret = regmap_write(rv3028->regmap, RV3028_OFFSET, offset >> 1); + if (ret < 0) + goto exit_eerd; + + ret = regmap_update_bits(rv3028->regmap, RV3028_BACKUP, BIT(7), + offset << 7); + if (ret < 0) + goto exit_eerd; + + return rv3028_update_eeprom(rv3028, eerd); + +exit_eerd: + rv3028_exit_eerd(rv3028, eerd); + + return ret; + +} + +static int rv3028_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) +{ + struct rv3028_data *rv3028 = dev_get_drvdata(dev); + int status, ret = 0; + + switch (cmd) { + case RTC_VL_READ: + ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status); + if (ret < 0) + return ret; + + status = status & RV3028_STATUS_PORF ? RTC_VL_DATA_INVALID : 0; + return put_user(status, (unsigned int __user *)arg); + + default: + return -ENOIOCTLCMD; + } +} + +static int rv3028_nvram_write(void *priv, unsigned int offset, void *val, + size_t bytes) +{ + return regmap_bulk_write(priv, RV3028_RAM1 + offset, val, bytes); +} + +static int rv3028_nvram_read(void *priv, unsigned int offset, void *val, + size_t bytes) +{ + return regmap_bulk_read(priv, RV3028_RAM1 + offset, val, bytes); +} + +static int rv3028_eeprom_write(void *priv, unsigned int offset, void *val, + size_t bytes) +{ + struct rv3028_data *rv3028 = priv; + u32 status, eerd; + int i, ret; + u8 *buf = val; + + ret = rv3028_enter_eerd(rv3028, &eerd); + if (ret) + return ret; + + for (i = 0; i < bytes; i++) { + ret = regmap_write(rv3028->regmap, RV3028_EEPROM_ADDR, offset + i); + if (ret) + goto restore_eerd; + + ret = regmap_write(rv3028->regmap, RV3028_EEPROM_DATA, buf[i]); + if (ret) + goto restore_eerd; + + ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0); + if (ret) + goto restore_eerd; + + ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, + RV3028_EEPROM_CMD_WRITE); + if (ret) + goto restore_eerd; + + usleep_range(RV3028_EEBUSY_POLL, RV3028_EEBUSY_TIMEOUT); + + ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status, + !(status & RV3028_STATUS_EEBUSY), + RV3028_EEBUSY_POLL, + RV3028_EEBUSY_TIMEOUT); + if (ret) + goto restore_eerd; + } + +restore_eerd: + rv3028_exit_eerd(rv3028, eerd); + + return ret; +} + +static int rv3028_eeprom_read(void *priv, unsigned int offset, void *val, + size_t bytes) +{ + struct rv3028_data *rv3028 = priv; + u32 status, eerd, data; + int i, ret; + u8 *buf = val; + + ret = rv3028_enter_eerd(rv3028, &eerd); + if (ret) + return ret; + + for (i = 0; i < bytes; i++) { + ret = regmap_write(rv3028->regmap, RV3028_EEPROM_ADDR, offset + i); + if (ret) + goto restore_eerd; + + ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, 0x0); + if (ret) + goto restore_eerd; + + ret = regmap_write(rv3028->regmap, RV3028_EEPROM_CMD, + RV3028_EEPROM_CMD_READ); + if (ret) + goto restore_eerd; + + ret = regmap_read_poll_timeout(rv3028->regmap, RV3028_STATUS, status, + !(status & RV3028_STATUS_EEBUSY), + RV3028_EEBUSY_POLL, + RV3028_EEBUSY_TIMEOUT); + if (ret) + goto restore_eerd; + + ret = regmap_read(rv3028->regmap, RV3028_EEPROM_DATA, &data); + if (ret) + goto restore_eerd; + buf[i] = data; + } + +restore_eerd: + rv3028_exit_eerd(rv3028, eerd); + + return ret; +} + +#ifdef CONFIG_COMMON_CLK +#define clkout_hw_to_rv3028(hw) container_of(hw, struct rv3028_data, clkout_hw) + +static int clkout_rates[] = { + 32768, + 8192, + 1024, + 64, + 32, + 1, +}; + +static unsigned long rv3028_clkout_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + int clkout, ret; + struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw); + + ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout); + if (ret < 0) + return 0; + + clkout &= RV3028_CLKOUT_FD_MASK; + return clkout_rates[clkout]; +} + +static long rv3028_clkout_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(clkout_rates); i++) + if (clkout_rates[i] <= rate) + return clkout_rates[i]; + + return 0; +} + +static int rv3028_clkout_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + int i, ret; + u32 enabled; + struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw); + + ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &enabled); + if (ret < 0) + return ret; + + ret = regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0); + if (ret < 0) + return ret; + + enabled &= RV3028_CLKOUT_CLKOE; + + for (i = 0; i < ARRAY_SIZE(clkout_rates); i++) + if (clkout_rates[i] == rate) + return rv3028_update_cfg(rv3028, RV3028_CLKOUT, 0xff, + RV3028_CLKOUT_CLKSY | enabled | i); + + return -EINVAL; +} + +static int rv3028_clkout_prepare(struct clk_hw *hw) +{ + struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw); + + return regmap_write(rv3028->regmap, RV3028_CLKOUT, + RV3028_CLKOUT_CLKSY | RV3028_CLKOUT_CLKOE); +} + +static void rv3028_clkout_unprepare(struct clk_hw *hw) +{ + struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw); + + regmap_write(rv3028->regmap, RV3028_CLKOUT, 0x0); + regmap_update_bits(rv3028->regmap, RV3028_STATUS, + RV3028_STATUS_CLKF, 0); +} + +static int rv3028_clkout_is_prepared(struct clk_hw *hw) +{ + int clkout, ret; + struct rv3028_data *rv3028 = clkout_hw_to_rv3028(hw); + + ret = regmap_read(rv3028->regmap, RV3028_CLKOUT, &clkout); + if (ret < 0) + return ret; + + return !!(clkout & RV3028_CLKOUT_CLKOE); +} + +static const struct clk_ops rv3028_clkout_ops = { + .prepare = rv3028_clkout_prepare, + .unprepare = rv3028_clkout_unprepare, + .is_prepared = rv3028_clkout_is_prepared, + .recalc_rate = rv3028_clkout_recalc_rate, + .round_rate = rv3028_clkout_round_rate, + .set_rate = rv3028_clkout_set_rate, +}; + +static int rv3028_clkout_register_clk(struct rv3028_data *rv3028, + struct i2c_client *client) +{ + int ret; + struct clk *clk; + struct clk_init_data init; + struct device_node *node = client->dev.of_node; + + ret = regmap_update_bits(rv3028->regmap, RV3028_STATUS, + RV3028_STATUS_CLKF, 0); + if (ret < 0) + return ret; + + init.name = "rv3028-clkout"; + init.ops = &rv3028_clkout_ops; + init.flags = 0; + init.parent_names = NULL; + init.num_parents = 0; + rv3028->clkout_hw.init = &init; + + /* optional override of the clockname */ + of_property_read_string(node, "clock-output-names", &init.name); + + /* register the clock */ + clk = devm_clk_register(&client->dev, &rv3028->clkout_hw); + if (!IS_ERR(clk)) + of_clk_add_provider(node, of_clk_src_simple_get, clk); + + return 0; +} +#endif + +static struct rtc_class_ops rv3028_rtc_ops = { + .read_time = rv3028_get_time, + .set_time = rv3028_set_time, + .read_offset = rv3028_read_offset, + .set_offset = rv3028_set_offset, + .ioctl = rv3028_ioctl, +}; + +static const struct regmap_config regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = 0x37, +}; + +static int rv3028_probe(struct i2c_client *client) +{ + struct rv3028_data *rv3028; + int ret, status; + u32 ohms; + struct nvmem_config nvmem_cfg = { + .name = "rv3028_nvram", + .word_size = 1, + .stride = 1, + .size = 2, + .type = NVMEM_TYPE_BATTERY_BACKED, + .reg_read = rv3028_nvram_read, + .reg_write = rv3028_nvram_write, + }; + struct nvmem_config eeprom_cfg = { + .name = "rv3028_eeprom", + .word_size = 1, + .stride = 1, + .size = 43, + .type = NVMEM_TYPE_EEPROM, + .reg_read = rv3028_eeprom_read, + .reg_write = rv3028_eeprom_write, + }; + + rv3028 = devm_kzalloc(&client->dev, sizeof(struct rv3028_data), + GFP_KERNEL); + if (!rv3028) + return -ENOMEM; + + rv3028->regmap = devm_regmap_init_i2c(client, ®map_config); + if (IS_ERR(rv3028->regmap)) + return PTR_ERR(rv3028->regmap); + + i2c_set_clientdata(client, rv3028); + + ret = regmap_read(rv3028->regmap, RV3028_STATUS, &status); + if (ret < 0) + return ret; + + if (status & RV3028_STATUS_PORF) + dev_warn(&client->dev, "Voltage low, data loss detected.\n"); + + if (status & RV3028_STATUS_AF) + dev_warn(&client->dev, "An alarm may have been missed.\n"); + + rv3028->rtc = devm_rtc_allocate_device(&client->dev); + if (IS_ERR(rv3028->rtc)) + return PTR_ERR(rv3028->rtc); + + if (client->irq > 0) { + ret = devm_request_threaded_irq(&client->dev, client->irq, + NULL, rv3028_handle_irq, + IRQF_TRIGGER_LOW | IRQF_ONESHOT, + "rv3028", rv3028); + if (ret) { + dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n"); + client->irq = 0; + } else { + rv3028_rtc_ops.read_alarm = rv3028_get_alarm; + rv3028_rtc_ops.set_alarm = rv3028_set_alarm; + rv3028_rtc_ops.alarm_irq_enable = rv3028_alarm_irq_enable; + } + } + + ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL1, + RV3028_CTRL1_WADA, RV3028_CTRL1_WADA); + if (ret) + return ret; + + /* setup timestamping */ + ret = regmap_update_bits(rv3028->regmap, RV3028_CTRL2, + RV3028_CTRL2_EIE | RV3028_CTRL2_TSE, + RV3028_CTRL2_EIE | RV3028_CTRL2_TSE); + if (ret) + return ret; + + /* setup trickle charger */ + if (!device_property_read_u32(&client->dev, "trickle-resistor-ohms", + &ohms)) { + int i; + + for (i = 0; i < ARRAY_SIZE(rv3028_trickle_resistors); i++) + if (ohms == rv3028_trickle_resistors[i]) + break; + + if (i < ARRAY_SIZE(rv3028_trickle_resistors)) { + ret = rv3028_update_cfg(rv3028, RV3028_BACKUP, RV3028_BACKUP_TCE | + RV3028_BACKUP_TCR_MASK, RV3028_BACKUP_TCE | i); + if (ret) + return ret; + } else { + dev_warn(&client->dev, "invalid trickle resistor value\n"); + } + } + + ret = rtc_add_group(rv3028->rtc, &rv3028_attr_group); + if (ret) + return ret; + + rv3028->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; + rv3028->rtc->range_max = RTC_TIMESTAMP_END_2099; + rv3028->rtc->ops = &rv3028_rtc_ops; + ret = rtc_register_device(rv3028->rtc); + if (ret) + return ret; + + nvmem_cfg.priv = rv3028->regmap; + rtc_nvmem_register(rv3028->rtc, &nvmem_cfg); + eeprom_cfg.priv = rv3028; + rtc_nvmem_register(rv3028->rtc, &eeprom_cfg); + + rv3028->rtc->max_user_freq = 1; + +#ifdef CONFIG_COMMON_CLK + rv3028_clkout_register_clk(rv3028, client); +#endif + return 0; +} + +static const struct of_device_id rv3028_of_match[] = { + { .compatible = "microcrystal,rv3028", }, + { } +}; +MODULE_DEVICE_TABLE(of, rv3028_of_match); + +static struct i2c_driver rv3028_driver = { + .driver = { + .name = "rtc-rv3028", + .of_match_table = of_match_ptr(rv3028_of_match), + }, + .probe_new = rv3028_probe, +}; +module_i2c_driver(rv3028_driver); + +MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>"); +MODULE_DESCRIPTION("Micro Crystal RV3028 RTC driver"); +MODULE_LICENSE("GPL v2"); |