diff options
Diffstat (limited to 'drivers/rtc/rtc-fm3130.c')
| -rw-r--r-- | drivers/rtc/rtc-fm3130.c | 529 |
1 files changed, 529 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-fm3130.c b/drivers/rtc/rtc-fm3130.c new file mode 100644 index 000000000..f59bb81f2 --- /dev/null +++ b/drivers/rtc/rtc-fm3130.c @@ -0,0 +1,529 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * rtc-fm3130.c - RTC driver for Ramtron FM3130 I2C chip. + * + * Copyright (C) 2008 Sergey Lapin + * Based on ds1307 driver by James Chapman and David Brownell + */ + +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/rtc.h> +#include <linux/bcd.h> +#include <linux/slab.h> + +#define FM3130_RTC_CONTROL (0x0) +#define FM3130_CAL_CONTROL (0x1) +#define FM3130_RTC_SECONDS (0x2) +#define FM3130_RTC_MINUTES (0x3) +#define FM3130_RTC_HOURS (0x4) +#define FM3130_RTC_DAY (0x5) +#define FM3130_RTC_DATE (0x6) +#define FM3130_RTC_MONTHS (0x7) +#define FM3130_RTC_YEARS (0x8) + +#define FM3130_ALARM_SECONDS (0x9) +#define FM3130_ALARM_MINUTES (0xa) +#define FM3130_ALARM_HOURS (0xb) +#define FM3130_ALARM_DATE (0xc) +#define FM3130_ALARM_MONTHS (0xd) +#define FM3130_ALARM_WP_CONTROL (0xe) + +#define FM3130_CAL_CONTROL_BIT_nOSCEN (1 << 7) /* Osciallator enabled */ +#define FM3130_RTC_CONTROL_BIT_LB (1 << 7) /* Low battery */ +#define FM3130_RTC_CONTROL_BIT_AF (1 << 6) /* Alarm flag */ +#define FM3130_RTC_CONTROL_BIT_CF (1 << 5) /* Century overflow */ +#define FM3130_RTC_CONTROL_BIT_POR (1 << 4) /* Power on reset */ +#define FM3130_RTC_CONTROL_BIT_AEN (1 << 3) /* Alarm enable */ +#define FM3130_RTC_CONTROL_BIT_CAL (1 << 2) /* Calibration mode */ +#define FM3130_RTC_CONTROL_BIT_WRITE (1 << 1) /* W=1 -> write mode W=0 normal */ +#define FM3130_RTC_CONTROL_BIT_READ (1 << 0) /* R=1 -> read mode R=0 normal */ + +#define FM3130_CLOCK_REGS 7 +#define FM3130_ALARM_REGS 5 + +struct fm3130 { + u8 reg_addr_time; + u8 reg_addr_alarm; + u8 regs[15]; + struct i2c_msg msg[4]; + struct i2c_client *client; + struct rtc_device *rtc; + int alarm_valid; + int data_valid; +}; +static const struct i2c_device_id fm3130_id[] = { + { "fm3130", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, fm3130_id); + +#define FM3130_MODE_NORMAL 0 +#define FM3130_MODE_WRITE 1 +#define FM3130_MODE_READ 2 + +static void fm3130_rtc_mode(struct device *dev, int mode) +{ + struct fm3130 *fm3130 = dev_get_drvdata(dev); + + fm3130->regs[FM3130_RTC_CONTROL] = + i2c_smbus_read_byte_data(fm3130->client, FM3130_RTC_CONTROL); + switch (mode) { + case FM3130_MODE_NORMAL: + fm3130->regs[FM3130_RTC_CONTROL] &= + ~(FM3130_RTC_CONTROL_BIT_WRITE | + FM3130_RTC_CONTROL_BIT_READ); + break; + case FM3130_MODE_WRITE: + fm3130->regs[FM3130_RTC_CONTROL] |= FM3130_RTC_CONTROL_BIT_WRITE; + break; + case FM3130_MODE_READ: + fm3130->regs[FM3130_RTC_CONTROL] |= FM3130_RTC_CONTROL_BIT_READ; + break; + default: + dev_dbg(dev, "invalid mode %d\n", mode); + break; + } + + i2c_smbus_write_byte_data(fm3130->client, + FM3130_RTC_CONTROL, fm3130->regs[FM3130_RTC_CONTROL]); +} + +static int fm3130_get_time(struct device *dev, struct rtc_time *t) +{ + struct fm3130 *fm3130 = dev_get_drvdata(dev); + int tmp; + + if (!fm3130->data_valid) { + /* We have invalid data in RTC, probably due + to battery faults or other problems. Return EIO + for now, it will allow us to set data later instead + of error during probing which disables device */ + return -EIO; + } + fm3130_rtc_mode(dev, FM3130_MODE_READ); + + /* read the RTC date and time registers all at once */ + tmp = i2c_transfer(fm3130->client->adapter, fm3130->msg, 2); + if (tmp != 2) { + dev_err(dev, "%s error %d\n", "read", tmp); + return -EIO; + } + + fm3130_rtc_mode(dev, FM3130_MODE_NORMAL); + + dev_dbg(dev, "%s: %15ph\n", "read", fm3130->regs); + + t->tm_sec = bcd2bin(fm3130->regs[FM3130_RTC_SECONDS] & 0x7f); + t->tm_min = bcd2bin(fm3130->regs[FM3130_RTC_MINUTES] & 0x7f); + tmp = fm3130->regs[FM3130_RTC_HOURS] & 0x3f; + t->tm_hour = bcd2bin(tmp); + t->tm_wday = bcd2bin(fm3130->regs[FM3130_RTC_DAY] & 0x07) - 1; + t->tm_mday = bcd2bin(fm3130->regs[FM3130_RTC_DATE] & 0x3f); + tmp = fm3130->regs[FM3130_RTC_MONTHS] & 0x1f; + t->tm_mon = bcd2bin(tmp) - 1; + + /* assume 20YY not 19YY, and ignore CF bit */ + t->tm_year = bcd2bin(fm3130->regs[FM3130_RTC_YEARS]) + 100; + + dev_dbg(dev, "%s secs=%d, mins=%d, " + "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n", + "read", t->tm_sec, t->tm_min, + t->tm_hour, t->tm_mday, + t->tm_mon, t->tm_year, t->tm_wday); + + return 0; +} + + +static int fm3130_set_time(struct device *dev, struct rtc_time *t) +{ + struct fm3130 *fm3130 = dev_get_drvdata(dev); + int tmp, i; + u8 *buf = fm3130->regs; + + dev_dbg(dev, "%s secs=%d, mins=%d, " + "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n", + "write", t->tm_sec, t->tm_min, + t->tm_hour, t->tm_mday, + t->tm_mon, t->tm_year, t->tm_wday); + + /* first register addr */ + buf[FM3130_RTC_SECONDS] = bin2bcd(t->tm_sec); + buf[FM3130_RTC_MINUTES] = bin2bcd(t->tm_min); + buf[FM3130_RTC_HOURS] = bin2bcd(t->tm_hour); + buf[FM3130_RTC_DAY] = bin2bcd(t->tm_wday + 1); + buf[FM3130_RTC_DATE] = bin2bcd(t->tm_mday); + buf[FM3130_RTC_MONTHS] = bin2bcd(t->tm_mon + 1); + + /* assume 20YY not 19YY */ + tmp = t->tm_year - 100; + buf[FM3130_RTC_YEARS] = bin2bcd(tmp); + + dev_dbg(dev, "%s: %15ph\n", "write", buf); + + fm3130_rtc_mode(dev, FM3130_MODE_WRITE); + + /* Writing time registers, we don't support multibyte transfers */ + for (i = 0; i < FM3130_CLOCK_REGS; i++) { + i2c_smbus_write_byte_data(fm3130->client, + FM3130_RTC_SECONDS + i, + fm3130->regs[FM3130_RTC_SECONDS + i]); + } + + fm3130_rtc_mode(dev, FM3130_MODE_NORMAL); + + /* We assume here that data are valid once written */ + if (!fm3130->data_valid) + fm3130->data_valid = 1; + return 0; +} + +static int fm3130_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct fm3130 *fm3130 = dev_get_drvdata(dev); + int tmp; + struct rtc_time *tm = &alrm->time; + + if (!fm3130->alarm_valid) { + /* + * We have invalid alarm in RTC, probably due to battery faults + * or other problems. Return EIO for now, it will allow us to + * set alarm value later instead of error during probing which + * disables device + */ + return -EIO; + } + + /* read the RTC alarm registers all at once */ + tmp = i2c_transfer(fm3130->client->adapter, &fm3130->msg[2], 2); + if (tmp != 2) { + dev_err(dev, "%s error %d\n", "read", tmp); + return -EIO; + } + dev_dbg(dev, "alarm read %02x %02x %02x %02x %02x\n", + fm3130->regs[FM3130_ALARM_SECONDS], + fm3130->regs[FM3130_ALARM_MINUTES], + fm3130->regs[FM3130_ALARM_HOURS], + fm3130->regs[FM3130_ALARM_DATE], + fm3130->regs[FM3130_ALARM_MONTHS]); + + tm->tm_sec = bcd2bin(fm3130->regs[FM3130_ALARM_SECONDS] & 0x7F); + tm->tm_min = bcd2bin(fm3130->regs[FM3130_ALARM_MINUTES] & 0x7F); + tm->tm_hour = bcd2bin(fm3130->regs[FM3130_ALARM_HOURS] & 0x3F); + tm->tm_mday = bcd2bin(fm3130->regs[FM3130_ALARM_DATE] & 0x3F); + tm->tm_mon = bcd2bin(fm3130->regs[FM3130_ALARM_MONTHS] & 0x1F); + + if (tm->tm_mon > 0) + tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */ + + dev_dbg(dev, "%s secs=%d, mins=%d, " + "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n", + "read alarm", tm->tm_sec, tm->tm_min, + tm->tm_hour, tm->tm_mday, + tm->tm_mon, tm->tm_year, tm->tm_wday); + + /* check if alarm enabled */ + fm3130->regs[FM3130_RTC_CONTROL] = + i2c_smbus_read_byte_data(fm3130->client, FM3130_RTC_CONTROL); + + if ((fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_AEN) && + (~fm3130->regs[FM3130_RTC_CONTROL] & + FM3130_RTC_CONTROL_BIT_CAL)) { + alrm->enabled = 1; + } + + return 0; +} + +static int fm3130_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct fm3130 *fm3130 = dev_get_drvdata(dev); + struct rtc_time *tm = &alrm->time; + int i; + + dev_dbg(dev, "%s secs=%d, mins=%d, " + "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n", + "write alarm", tm->tm_sec, tm->tm_min, + tm->tm_hour, tm->tm_mday, + tm->tm_mon, tm->tm_year, tm->tm_wday); + + fm3130->regs[FM3130_ALARM_SECONDS] = + (tm->tm_sec != -1) ? bin2bcd(tm->tm_sec) : 0x80; + + fm3130->regs[FM3130_ALARM_MINUTES] = + (tm->tm_min != -1) ? bin2bcd(tm->tm_min) : 0x80; + + fm3130->regs[FM3130_ALARM_HOURS] = + (tm->tm_hour != -1) ? bin2bcd(tm->tm_hour) : 0x80; + + fm3130->regs[FM3130_ALARM_DATE] = + (tm->tm_mday != -1) ? bin2bcd(tm->tm_mday) : 0x80; + + fm3130->regs[FM3130_ALARM_MONTHS] = + (tm->tm_mon != -1) ? bin2bcd(tm->tm_mon + 1) : 0x80; + + dev_dbg(dev, "alarm write %02x %02x %02x %02x %02x\n", + fm3130->regs[FM3130_ALARM_SECONDS], + fm3130->regs[FM3130_ALARM_MINUTES], + fm3130->regs[FM3130_ALARM_HOURS], + fm3130->regs[FM3130_ALARM_DATE], + fm3130->regs[FM3130_ALARM_MONTHS]); + /* Writing time registers, we don't support multibyte transfers */ + for (i = 0; i < FM3130_ALARM_REGS; i++) { + i2c_smbus_write_byte_data(fm3130->client, + FM3130_ALARM_SECONDS + i, + fm3130->regs[FM3130_ALARM_SECONDS + i]); + } + fm3130->regs[FM3130_RTC_CONTROL] = + i2c_smbus_read_byte_data(fm3130->client, FM3130_RTC_CONTROL); + + /* enable or disable alarm */ + if (alrm->enabled) { + i2c_smbus_write_byte_data(fm3130->client, FM3130_RTC_CONTROL, + (fm3130->regs[FM3130_RTC_CONTROL] & + ~(FM3130_RTC_CONTROL_BIT_CAL)) | + FM3130_RTC_CONTROL_BIT_AEN); + } else { + i2c_smbus_write_byte_data(fm3130->client, FM3130_RTC_CONTROL, + fm3130->regs[FM3130_RTC_CONTROL] & + ~(FM3130_RTC_CONTROL_BIT_CAL) & + ~(FM3130_RTC_CONTROL_BIT_AEN)); + } + + /* We assume here that data is valid once written */ + if (!fm3130->alarm_valid) + fm3130->alarm_valid = 1; + + return 0; +} + +static int fm3130_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct fm3130 *fm3130 = dev_get_drvdata(dev); + int ret = 0; + + fm3130->regs[FM3130_RTC_CONTROL] = + i2c_smbus_read_byte_data(fm3130->client, FM3130_RTC_CONTROL); + + dev_dbg(dev, "alarm_irq_enable: enable=%d, FM3130_RTC_CONTROL=%02x\n", + enabled, fm3130->regs[FM3130_RTC_CONTROL]); + + switch (enabled) { + case 0: /* alarm off */ + ret = i2c_smbus_write_byte_data(fm3130->client, + FM3130_RTC_CONTROL, fm3130->regs[FM3130_RTC_CONTROL] & + ~(FM3130_RTC_CONTROL_BIT_CAL) & + ~(FM3130_RTC_CONTROL_BIT_AEN)); + break; + case 1: /* alarm on */ + ret = i2c_smbus_write_byte_data(fm3130->client, + FM3130_RTC_CONTROL, (fm3130->regs[FM3130_RTC_CONTROL] & + ~(FM3130_RTC_CONTROL_BIT_CAL)) | + FM3130_RTC_CONTROL_BIT_AEN); + break; + default: + ret = -EINVAL; + break; + } + + return ret; +} + +static const struct rtc_class_ops fm3130_rtc_ops = { + .read_time = fm3130_get_time, + .set_time = fm3130_set_time, + .read_alarm = fm3130_read_alarm, + .set_alarm = fm3130_set_alarm, + .alarm_irq_enable = fm3130_alarm_irq_enable, +}; + +static struct i2c_driver fm3130_driver; + +static int fm3130_probe(struct i2c_client *client) +{ + struct fm3130 *fm3130; + int err = -ENODEV; + int tmp; + struct i2c_adapter *adapter = client->adapter; + + if (!i2c_check_functionality(adapter, + I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) + return -EIO; + + fm3130 = devm_kzalloc(&client->dev, sizeof(struct fm3130), GFP_KERNEL); + + if (!fm3130) + return -ENOMEM; + + fm3130->client = client; + i2c_set_clientdata(client, fm3130); + fm3130->reg_addr_time = FM3130_RTC_SECONDS; + fm3130->reg_addr_alarm = FM3130_ALARM_SECONDS; + + /* Messages to read time */ + fm3130->msg[0].addr = client->addr; + fm3130->msg[0].flags = 0; + fm3130->msg[0].len = 1; + fm3130->msg[0].buf = &fm3130->reg_addr_time; + + fm3130->msg[1].addr = client->addr; + fm3130->msg[1].flags = I2C_M_RD; + fm3130->msg[1].len = FM3130_CLOCK_REGS; + fm3130->msg[1].buf = &fm3130->regs[FM3130_RTC_SECONDS]; + + /* Messages to read alarm */ + fm3130->msg[2].addr = client->addr; + fm3130->msg[2].flags = 0; + fm3130->msg[2].len = 1; + fm3130->msg[2].buf = &fm3130->reg_addr_alarm; + + fm3130->msg[3].addr = client->addr; + fm3130->msg[3].flags = I2C_M_RD; + fm3130->msg[3].len = FM3130_ALARM_REGS; + fm3130->msg[3].buf = &fm3130->regs[FM3130_ALARM_SECONDS]; + + fm3130->alarm_valid = 0; + fm3130->data_valid = 0; + + tmp = i2c_transfer(adapter, fm3130->msg, 4); + if (tmp != 4) { + dev_dbg(&client->dev, "read error %d\n", tmp); + err = -EIO; + goto exit_free; + } + + fm3130->regs[FM3130_RTC_CONTROL] = + i2c_smbus_read_byte_data(client, FM3130_RTC_CONTROL); + fm3130->regs[FM3130_CAL_CONTROL] = + i2c_smbus_read_byte_data(client, FM3130_CAL_CONTROL); + + /* Disabling calibration mode */ + if (fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_CAL) { + i2c_smbus_write_byte_data(client, FM3130_RTC_CONTROL, + fm3130->regs[FM3130_RTC_CONTROL] & + ~(FM3130_RTC_CONTROL_BIT_CAL)); + dev_warn(&client->dev, "Disabling calibration mode!\n"); + } + + /* Disabling read and write modes */ + if (fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_WRITE || + fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_READ) { + i2c_smbus_write_byte_data(client, FM3130_RTC_CONTROL, + fm3130->regs[FM3130_RTC_CONTROL] & + ~(FM3130_RTC_CONTROL_BIT_READ | + FM3130_RTC_CONTROL_BIT_WRITE)); + dev_warn(&client->dev, "Disabling READ or WRITE mode!\n"); + } + + /* oscillator off? turn it on, so clock can tick. */ + if (fm3130->regs[FM3130_CAL_CONTROL] & FM3130_CAL_CONTROL_BIT_nOSCEN) + i2c_smbus_write_byte_data(client, FM3130_CAL_CONTROL, + fm3130->regs[FM3130_CAL_CONTROL] & + ~(FM3130_CAL_CONTROL_BIT_nOSCEN)); + + /* low battery? clear flag, and warn */ + if (fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_LB) { + i2c_smbus_write_byte_data(client, FM3130_RTC_CONTROL, + fm3130->regs[FM3130_RTC_CONTROL] & + ~(FM3130_RTC_CONTROL_BIT_LB)); + dev_warn(&client->dev, "Low battery!\n"); + } + + /* check if Power On Reset bit is set */ + if (fm3130->regs[FM3130_RTC_CONTROL] & FM3130_RTC_CONTROL_BIT_POR) { + i2c_smbus_write_byte_data(client, FM3130_RTC_CONTROL, + fm3130->regs[FM3130_RTC_CONTROL] & + ~FM3130_RTC_CONTROL_BIT_POR); + dev_dbg(&client->dev, "POR bit is set\n"); + } + /* ACS is controlled by alarm */ + i2c_smbus_write_byte_data(client, FM3130_ALARM_WP_CONTROL, 0x80); + + /* alarm registers sanity check */ + tmp = bcd2bin(fm3130->regs[FM3130_RTC_SECONDS] & 0x7f); + if (tmp > 59) + goto bad_alarm; + + tmp = bcd2bin(fm3130->regs[FM3130_RTC_MINUTES] & 0x7f); + if (tmp > 59) + goto bad_alarm; + + tmp = bcd2bin(fm3130->regs[FM3130_RTC_HOURS] & 0x3f); + if (tmp > 23) + goto bad_alarm; + + tmp = bcd2bin(fm3130->regs[FM3130_RTC_DATE] & 0x3f); + if (tmp == 0 || tmp > 31) + goto bad_alarm; + + tmp = bcd2bin(fm3130->regs[FM3130_RTC_MONTHS] & 0x1f); + if (tmp == 0 || tmp > 12) + goto bad_alarm; + + fm3130->alarm_valid = 1; + +bad_alarm: + + /* clock registers sanity chek */ + tmp = bcd2bin(fm3130->regs[FM3130_RTC_SECONDS] & 0x7f); + if (tmp > 59) + goto bad_clock; + + tmp = bcd2bin(fm3130->regs[FM3130_RTC_MINUTES] & 0x7f); + if (tmp > 59) + goto bad_clock; + + tmp = bcd2bin(fm3130->regs[FM3130_RTC_HOURS] & 0x3f); + if (tmp > 23) + goto bad_clock; + + tmp = bcd2bin(fm3130->regs[FM3130_RTC_DAY] & 0x7); + if (tmp == 0 || tmp > 7) + goto bad_clock; + + tmp = bcd2bin(fm3130->regs[FM3130_RTC_DATE] & 0x3f); + if (tmp == 0 || tmp > 31) + goto bad_clock; + + tmp = bcd2bin(fm3130->regs[FM3130_RTC_MONTHS] & 0x1f); + if (tmp == 0 || tmp > 12) + goto bad_clock; + + fm3130->data_valid = 1; + +bad_clock: + + if (!fm3130->data_valid || !fm3130->alarm_valid) + dev_dbg(&client->dev, "%s: %15ph\n", "bogus registers", + fm3130->regs); + + /* We won't bail out here because we just got invalid data. + Time setting from u-boot doesn't work anyway */ + fm3130->rtc = devm_rtc_device_register(&client->dev, client->name, + &fm3130_rtc_ops, THIS_MODULE); + if (IS_ERR(fm3130->rtc)) { + err = PTR_ERR(fm3130->rtc); + dev_err(&client->dev, + "unable to register the class device\n"); + goto exit_free; + } + return 0; +exit_free: + return err; +} + +static struct i2c_driver fm3130_driver = { + .driver = { + .name = "rtc-fm3130", + }, + .probe_new = fm3130_probe, + .id_table = fm3130_id, +}; + +module_i2c_driver(fm3130_driver); + +MODULE_DESCRIPTION("RTC driver for FM3130"); +MODULE_AUTHOR("Sergey Lapin <slapin@ossfans.org>"); +MODULE_LICENSE("GPL"); + |