diff options
Diffstat (limited to 'drivers/rtc/rtc-rv3029c2.c')
| -rw-r--r-- | drivers/rtc/rtc-rv3029c2.c | 427 |
1 files changed, 427 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-rv3029c2.c b/drivers/rtc/rtc-rv3029c2.c new file mode 100644 index 00000000000..e9ac5a43be1 --- /dev/null +++ b/drivers/rtc/rtc-rv3029c2.c @@ -0,0 +1,427 @@ +/* + * Micro Crystal RV-3029C2 rtc class driver + * + * Author: Gregory Hermant <gregory.hermant@calao-systems.com> + * + * based on previously existing rtc class drivers + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * NOTE: Currently this driver only supports the bare minimum for read + * and write the RTC and alarms. The extra features provided by this chip + * (trickle charger, eeprom, T° compensation) are unavailable. + */ + +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/bcd.h> +#include <linux/rtc.h> + +/* Register map */ +/* control section */ +#define RV3029C2_ONOFF_CTRL 0x00 +#define RV3029C2_IRQ_CTRL 0x01 +#define RV3029C2_IRQ_CTRL_AIE (1 << 0) +#define RV3029C2_IRQ_FLAGS 0x02 +#define RV3029C2_IRQ_FLAGS_AF (1 << 0) +#define RV3029C2_STATUS 0x03 +#define RV3029C2_STATUS_VLOW1 (1 << 2) +#define RV3029C2_STATUS_VLOW2 (1 << 3) +#define RV3029C2_STATUS_SR (1 << 4) +#define RV3029C2_STATUS_PON (1 << 5) +#define RV3029C2_STATUS_EEBUSY (1 << 7) +#define RV3029C2_RST_CTRL 0x04 +#define RV3029C2_CONTROL_SECTION_LEN 0x05 + +/* watch section */ +#define RV3029C2_W_SEC 0x08 +#define RV3029C2_W_MINUTES 0x09 +#define RV3029C2_W_HOURS 0x0A +#define RV3029C2_REG_HR_12_24 (1<<6) /* 24h/12h mode */ +#define RV3029C2_REG_HR_PM (1<<5) /* PM/AM bit in 12h mode */ +#define RV3029C2_W_DATE 0x0B +#define RV3029C2_W_DAYS 0x0C +#define RV3029C2_W_MONTHS 0x0D +#define RV3029C2_W_YEARS 0x0E +#define RV3029C2_WATCH_SECTION_LEN 0x07 + +/* alarm section */ +#define RV3029C2_A_SC 0x10 +#define RV3029C2_A_MN 0x11 +#define RV3029C2_A_HR 0x12 +#define RV3029C2_A_DT 0x13 +#define RV3029C2_A_DW 0x14 +#define RV3029C2_A_MO 0x15 +#define RV3029C2_A_YR 0x16 +#define RV3029C2_ALARM_SECTION_LEN 0x07 + +/* timer section */ +#define RV3029C2_TIMER_LOW 0x18 +#define RV3029C2_TIMER_HIGH 0x19 + +/* temperature section */ +#define RV3029C2_TEMP_PAGE 0x20 + +/* eeprom data section */ +#define RV3029C2_E2P_EEDATA1 0x28 +#define RV3029C2_E2P_EEDATA2 0x29 + +/* eeprom control section */ +#define RV3029C2_CONTROL_E2P_EECTRL 0x30 +#define RV3029C2_TRICKLE_1K (1<<0) /* 1K resistance */ +#define RV3029C2_TRICKLE_5K (1<<1) /* 5K resistance */ +#define RV3029C2_TRICKLE_20K (1<<2) /* 20K resistance */ +#define RV3029C2_TRICKLE_80K (1<<3) /* 80K resistance */ +#define RV3029C2_CONTROL_E2P_XTALOFFSET 0x31 +#define RV3029C2_CONTROL_E2P_QCOEF 0x32 +#define RV3029C2_CONTROL_E2P_TURNOVER 0x33 + +/* user ram section */ +#define RV3029C2_USR1_RAM_PAGE 0x38 +#define RV3029C2_USR1_SECTION_LEN 0x04 +#define RV3029C2_USR2_RAM_PAGE 0x3C +#define RV3029C2_USR2_SECTION_LEN 0x04 + +static int +rv3029c2_i2c_read_regs(struct i2c_client *client, u8 reg, u8 *buf, + unsigned len) +{ + int ret; + + if ((reg > RV3029C2_USR1_RAM_PAGE + 7) || + (reg + len > RV3029C2_USR1_RAM_PAGE + 8)) + return -EINVAL; + + ret = i2c_smbus_read_i2c_block_data(client, reg, len, buf); + if (ret < 0) + return ret; + if (ret < len) + return -EIO; + return 0; +} + +static int +rv3029c2_i2c_write_regs(struct i2c_client *client, u8 reg, u8 const buf[], + unsigned len) +{ + if ((reg > RV3029C2_USR1_RAM_PAGE + 7) || + (reg + len > RV3029C2_USR1_RAM_PAGE + 8)) + return -EINVAL; + + return i2c_smbus_write_i2c_block_data(client, reg, len, buf); +} + +static int +rv3029c2_i2c_get_sr(struct i2c_client *client, u8 *buf) +{ + int ret = rv3029c2_i2c_read_regs(client, RV3029C2_STATUS, buf, 1); + + if (ret < 0) + return -EIO; + dev_dbg(&client->dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]); + return 0; +} + +static int +rv3029c2_i2c_set_sr(struct i2c_client *client, u8 val) +{ + u8 buf[1]; + int sr; + + buf[0] = val; + sr = rv3029c2_i2c_write_regs(client, RV3029C2_STATUS, buf, 1); + dev_dbg(&client->dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]); + if (sr < 0) + return -EIO; + return 0; +} + +static int +rv3029c2_i2c_read_time(struct i2c_client *client, struct rtc_time *tm) +{ + u8 buf[1]; + int ret; + u8 regs[RV3029C2_WATCH_SECTION_LEN] = { 0, }; + + ret = rv3029c2_i2c_get_sr(client, buf); + if (ret < 0) { + dev_err(&client->dev, "%s: reading SR failed\n", __func__); + return -EIO; + } + + ret = rv3029c2_i2c_read_regs(client, RV3029C2_W_SEC , regs, + RV3029C2_WATCH_SECTION_LEN); + if (ret < 0) { + dev_err(&client->dev, "%s: reading RTC section failed\n", + __func__); + return ret; + } + + tm->tm_sec = bcd2bin(regs[RV3029C2_W_SEC-RV3029C2_W_SEC]); + tm->tm_min = bcd2bin(regs[RV3029C2_W_MINUTES-RV3029C2_W_SEC]); + + /* HR field has a more complex interpretation */ + { + const u8 _hr = regs[RV3029C2_W_HOURS-RV3029C2_W_SEC]; + if (_hr & RV3029C2_REG_HR_12_24) { + /* 12h format */ + tm->tm_hour = bcd2bin(_hr & 0x1f); + if (_hr & RV3029C2_REG_HR_PM) /* PM flag set */ + tm->tm_hour += 12; + } else /* 24h format */ + tm->tm_hour = bcd2bin(_hr & 0x3f); + } + + tm->tm_mday = bcd2bin(regs[RV3029C2_W_DATE-RV3029C2_W_SEC]); + tm->tm_mon = bcd2bin(regs[RV3029C2_W_MONTHS-RV3029C2_W_SEC]) - 1; + tm->tm_year = bcd2bin(regs[RV3029C2_W_YEARS-RV3029C2_W_SEC]) + 100; + tm->tm_wday = bcd2bin(regs[RV3029C2_W_DAYS-RV3029C2_W_SEC]) - 1; + + return 0; +} + +static int rv3029c2_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + return rv3029c2_i2c_read_time(to_i2c_client(dev), tm); +} + +static int +rv3029c2_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm) +{ + struct rtc_time *const tm = &alarm->time; + int ret; + u8 regs[8]; + + ret = rv3029c2_i2c_get_sr(client, regs); + if (ret < 0) { + dev_err(&client->dev, "%s: reading SR failed\n", __func__); + return -EIO; + } + + ret = rv3029c2_i2c_read_regs(client, RV3029C2_A_SC, regs, + RV3029C2_ALARM_SECTION_LEN); + + if (ret < 0) { + dev_err(&client->dev, "%s: reading alarm section failed\n", + __func__); + return ret; + } + + tm->tm_sec = bcd2bin(regs[RV3029C2_A_SC-RV3029C2_A_SC] & 0x7f); + tm->tm_min = bcd2bin(regs[RV3029C2_A_MN-RV3029C2_A_SC] & 0x7f); + tm->tm_hour = bcd2bin(regs[RV3029C2_A_HR-RV3029C2_A_SC] & 0x3f); + tm->tm_mday = bcd2bin(regs[RV3029C2_A_DT-RV3029C2_A_SC] & 0x3f); + tm->tm_mon = bcd2bin(regs[RV3029C2_A_MO-RV3029C2_A_SC] & 0x1f) - 1; + tm->tm_year = bcd2bin(regs[RV3029C2_A_YR-RV3029C2_A_SC] & 0x7f) + 100; + tm->tm_wday = bcd2bin(regs[RV3029C2_A_DW-RV3029C2_A_SC] & 0x07) - 1; + + return 0; +} + +static int +rv3029c2_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + return rv3029c2_i2c_read_alarm(to_i2c_client(dev), alarm); +} + +static int rv3029c2_rtc_i2c_alarm_set_irq(struct i2c_client *client, + int enable) +{ + int ret; + u8 buf[1]; + + /* enable AIE irq */ + ret = rv3029c2_i2c_read_regs(client, RV3029C2_IRQ_CTRL, buf, 1); + if (ret < 0) { + dev_err(&client->dev, "can't read INT reg\n"); + return ret; + } + if (enable) + buf[0] |= RV3029C2_IRQ_CTRL_AIE; + else + buf[0] &= ~RV3029C2_IRQ_CTRL_AIE; + + ret = rv3029c2_i2c_write_regs(client, RV3029C2_IRQ_CTRL, buf, 1); + if (ret < 0) { + dev_err(&client->dev, "can't set INT reg\n"); + return ret; + } + + return 0; +} + +static int rv3029c2_rtc_i2c_set_alarm(struct i2c_client *client, + struct rtc_wkalrm *alarm) +{ + struct rtc_time *const tm = &alarm->time; + int ret; + u8 regs[8]; + + /* + * The clock has an 8 bit wide bcd-coded register (they never learn) + * for the year. tm_year is an offset from 1900 and we are interested + * in the 2000-2099 range, so any value less than 100 is invalid. + */ + if (tm->tm_year < 100) + return -EINVAL; + + ret = rv3029c2_i2c_get_sr(client, regs); + if (ret < 0) { + dev_err(&client->dev, "%s: reading SR failed\n", __func__); + return -EIO; + } + regs[RV3029C2_A_SC-RV3029C2_A_SC] = bin2bcd(tm->tm_sec & 0x7f); + regs[RV3029C2_A_MN-RV3029C2_A_SC] = bin2bcd(tm->tm_min & 0x7f); + regs[RV3029C2_A_HR-RV3029C2_A_SC] = bin2bcd(tm->tm_hour & 0x3f); + regs[RV3029C2_A_DT-RV3029C2_A_SC] = bin2bcd(tm->tm_mday & 0x3f); + regs[RV3029C2_A_MO-RV3029C2_A_SC] = bin2bcd((tm->tm_mon & 0x1f) - 1); + regs[RV3029C2_A_DW-RV3029C2_A_SC] = bin2bcd((tm->tm_wday & 7) - 1); + regs[RV3029C2_A_YR-RV3029C2_A_SC] = bin2bcd((tm->tm_year & 0x7f) - 100); + + ret = rv3029c2_i2c_write_regs(client, RV3029C2_A_SC, regs, + RV3029C2_ALARM_SECTION_LEN); + if (ret < 0) + return ret; + + if (alarm->enabled) { + u8 buf[1]; + + /* clear AF flag */ + ret = rv3029c2_i2c_read_regs(client, RV3029C2_IRQ_FLAGS, + buf, 1); + if (ret < 0) { + dev_err(&client->dev, "can't read alarm flag\n"); + return ret; + } + buf[0] &= ~RV3029C2_IRQ_FLAGS_AF; + ret = rv3029c2_i2c_write_regs(client, RV3029C2_IRQ_FLAGS, + buf, 1); + if (ret < 0) { + dev_err(&client->dev, "can't set alarm flag\n"); + return ret; + } + /* enable AIE irq */ + ret = rv3029c2_rtc_i2c_alarm_set_irq(client, 1); + if (ret) + return ret; + + dev_dbg(&client->dev, "alarm IRQ armed\n"); + } else { + /* disable AIE irq */ + ret = rv3029c2_rtc_i2c_alarm_set_irq(client, 0); + if (ret) + return ret; + + dev_dbg(&client->dev, "alarm IRQ disabled\n"); + } + + return 0; +} + +static int rv3029c2_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + return rv3029c2_rtc_i2c_set_alarm(to_i2c_client(dev), alarm); +} + +static int +rv3029c2_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm) +{ + u8 regs[8]; + int ret; + + /* + * The clock has an 8 bit wide bcd-coded register (they never learn) + * for the year. tm_year is an offset from 1900 and we are interested + * in the 2000-2099 range, so any value less than 100 is invalid. + */ + if (tm->tm_year < 100) + return -EINVAL; + + regs[RV3029C2_W_SEC-RV3029C2_W_SEC] = bin2bcd(tm->tm_sec); + regs[RV3029C2_W_MINUTES-RV3029C2_W_SEC] = bin2bcd(tm->tm_min); + regs[RV3029C2_W_HOURS-RV3029C2_W_SEC] = bin2bcd(tm->tm_hour); + regs[RV3029C2_W_DATE-RV3029C2_W_SEC] = bin2bcd(tm->tm_mday); + regs[RV3029C2_W_MONTHS-RV3029C2_W_SEC] = bin2bcd(tm->tm_mon+1); + regs[RV3029C2_W_DAYS-RV3029C2_W_SEC] = bin2bcd((tm->tm_wday & 7)+1); + regs[RV3029C2_W_YEARS-RV3029C2_W_SEC] = bin2bcd(tm->tm_year - 100); + + ret = rv3029c2_i2c_write_regs(client, RV3029C2_W_SEC, regs, + RV3029C2_WATCH_SECTION_LEN); + if (ret < 0) + return ret; + + ret = rv3029c2_i2c_get_sr(client, regs); + if (ret < 0) { + dev_err(&client->dev, "%s: reading SR failed\n", __func__); + return ret; + } + /* clear PON bit */ + ret = rv3029c2_i2c_set_sr(client, (regs[0] & ~RV3029C2_STATUS_PON)); + if (ret < 0) { + dev_err(&client->dev, "%s: reading SR failed\n", __func__); + return ret; + } + + return 0; +} + +static int rv3029c2_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + return rv3029c2_i2c_set_time(to_i2c_client(dev), tm); +} + +static const struct rtc_class_ops rv3029c2_rtc_ops = { + .read_time = rv3029c2_rtc_read_time, + .set_time = rv3029c2_rtc_set_time, + .read_alarm = rv3029c2_rtc_read_alarm, + .set_alarm = rv3029c2_rtc_set_alarm, +}; + +static struct i2c_device_id rv3029c2_id[] = { + { "rv3029c2", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, rv3029c2_id); + +static int rv3029c2_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct rtc_device *rtc; + int rc = 0; + u8 buf[1]; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_EMUL)) + return -ENODEV; + + rc = rv3029c2_i2c_get_sr(client, buf); + if (rc < 0) { + dev_err(&client->dev, "reading status failed\n"); + return rc; + } + + rtc = devm_rtc_device_register(&client->dev, client->name, + &rv3029c2_rtc_ops, THIS_MODULE); + + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + i2c_set_clientdata(client, rtc); + + return 0; +} + +static struct i2c_driver rv3029c2_driver = { + .driver = { + .name = "rtc-rv3029c2", + }, + .probe = rv3029c2_probe, + .id_table = rv3029c2_id, +}; + +module_i2c_driver(rv3029c2_driver); + +MODULE_AUTHOR("Gregory Hermant <gregory.hermant@calao-systems.com>"); +MODULE_DESCRIPTION("Micro Crystal RV3029C2 RTC driver"); +MODULE_LICENSE("GPL"); |