diff options
Diffstat (limited to 'drivers/rtc/rtc-pcf85363.c')
| -rw-r--r-- | drivers/rtc/rtc-pcf85363.c | 402 |
1 files changed, 402 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-pcf85363.c b/drivers/rtc/rtc-pcf85363.c new file mode 100644 index 000000000..c3702684b --- /dev/null +++ b/drivers/rtc/rtc-pcf85363.c @@ -0,0 +1,402 @@ +/* + * drivers/rtc/rtc-pcf85363.c + * + * Driver for NXP PCF85363 real-time clock. + * + * Copyright (C) 2017 Eric Nelson + * + * 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. + * + * Based loosely on rtc-8583 by Russell King, Wolfram Sang and Juergen Beisert + */ +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/slab.h> +#include <linux/rtc.h> +#include <linux/init.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/bcd.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/regmap.h> + +/* + * Date/Time registers + */ +#define DT_100THS 0x00 +#define DT_SECS 0x01 +#define DT_MINUTES 0x02 +#define DT_HOURS 0x03 +#define DT_DAYS 0x04 +#define DT_WEEKDAYS 0x05 +#define DT_MONTHS 0x06 +#define DT_YEARS 0x07 + +/* + * Alarm registers + */ +#define DT_SECOND_ALM1 0x08 +#define DT_MINUTE_ALM1 0x09 +#define DT_HOUR_ALM1 0x0a +#define DT_DAY_ALM1 0x0b +#define DT_MONTH_ALM1 0x0c +#define DT_MINUTE_ALM2 0x0d +#define DT_HOUR_ALM2 0x0e +#define DT_WEEKDAY_ALM2 0x0f +#define DT_ALARM_EN 0x10 + +/* + * Time stamp registers + */ +#define DT_TIMESTAMP1 0x11 +#define DT_TIMESTAMP2 0x17 +#define DT_TIMESTAMP3 0x1d +#define DT_TS_MODE 0x23 + +/* + * control registers + */ +#define CTRL_OFFSET 0x24 +#define CTRL_OSCILLATOR 0x25 +#define CTRL_BATTERY 0x26 +#define CTRL_PIN_IO 0x27 +#define CTRL_FUNCTION 0x28 +#define CTRL_INTA_EN 0x29 +#define CTRL_INTB_EN 0x2a +#define CTRL_FLAGS 0x2b +#define CTRL_RAMBYTE 0x2c +#define CTRL_WDOG 0x2d +#define CTRL_STOP_EN 0x2e +#define CTRL_RESETS 0x2f +#define CTRL_RAM 0x40 + +#define ALRM_SEC_A1E BIT(0) +#define ALRM_MIN_A1E BIT(1) +#define ALRM_HR_A1E BIT(2) +#define ALRM_DAY_A1E BIT(3) +#define ALRM_MON_A1E BIT(4) +#define ALRM_MIN_A2E BIT(5) +#define ALRM_HR_A2E BIT(6) +#define ALRM_DAY_A2E BIT(7) + +#define INT_WDIE BIT(0) +#define INT_BSIE BIT(1) +#define INT_TSRIE BIT(2) +#define INT_A2IE BIT(3) +#define INT_A1IE BIT(4) +#define INT_OIE BIT(5) +#define INT_PIE BIT(6) +#define INT_ILP BIT(7) + +#define FLAGS_TSR1F BIT(0) +#define FLAGS_TSR2F BIT(1) +#define FLAGS_TSR3F BIT(2) +#define FLAGS_BSF BIT(3) +#define FLAGS_WDF BIT(4) +#define FLAGS_A1F BIT(5) +#define FLAGS_A2F BIT(6) +#define FLAGS_PIF BIT(7) + +#define PIN_IO_INTAPM GENMASK(1, 0) +#define PIN_IO_INTA_CLK 0 +#define PIN_IO_INTA_BAT 1 +#define PIN_IO_INTA_OUT 2 +#define PIN_IO_INTA_HIZ 3 + +#define STOP_EN_STOP BIT(0) + +#define RESET_CPR 0xa4 + +#define NVRAM_SIZE 0x40 + +static struct i2c_driver pcf85363_driver; + +struct pcf85363 { + struct device *dev; + struct rtc_device *rtc; + struct regmap *regmap; +}; + +static int pcf85363_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct pcf85363 *pcf85363 = dev_get_drvdata(dev); + unsigned char buf[DT_YEARS + 1]; + int ret, len = sizeof(buf); + + /* read the RTC date and time registers all at once */ + ret = regmap_bulk_read(pcf85363->regmap, DT_100THS, buf, len); + if (ret) { + dev_err(dev, "%s: error %d\n", __func__, ret); + return ret; + } + + tm->tm_year = bcd2bin(buf[DT_YEARS]); + /* adjust for 1900 base of rtc_time */ + tm->tm_year += 100; + + tm->tm_wday = buf[DT_WEEKDAYS] & 7; + buf[DT_SECS] &= 0x7F; + tm->tm_sec = bcd2bin(buf[DT_SECS]); + buf[DT_MINUTES] &= 0x7F; + tm->tm_min = bcd2bin(buf[DT_MINUTES]); + tm->tm_hour = bcd2bin(buf[DT_HOURS]); + tm->tm_mday = bcd2bin(buf[DT_DAYS]); + tm->tm_mon = bcd2bin(buf[DT_MONTHS]) - 1; + + return 0; +} + +static int pcf85363_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct pcf85363 *pcf85363 = dev_get_drvdata(dev); + unsigned char tmp[11]; + unsigned char *buf = &tmp[2]; + int ret; + + tmp[0] = STOP_EN_STOP; + tmp[1] = RESET_CPR; + + buf[DT_100THS] = 0; + buf[DT_SECS] = bin2bcd(tm->tm_sec); + buf[DT_MINUTES] = bin2bcd(tm->tm_min); + buf[DT_HOURS] = bin2bcd(tm->tm_hour); + buf[DT_DAYS] = bin2bcd(tm->tm_mday); + buf[DT_WEEKDAYS] = tm->tm_wday; + buf[DT_MONTHS] = bin2bcd(tm->tm_mon + 1); + buf[DT_YEARS] = bin2bcd(tm->tm_year % 100); + + ret = regmap_bulk_write(pcf85363->regmap, CTRL_STOP_EN, + tmp, 2); + if (ret) + return ret; + + ret = regmap_bulk_write(pcf85363->regmap, DT_100THS, + buf, sizeof(tmp) - 2); + if (ret) + return ret; + + return regmap_write(pcf85363->regmap, CTRL_STOP_EN, 0); +} + +static int pcf85363_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct pcf85363 *pcf85363 = dev_get_drvdata(dev); + unsigned char buf[DT_MONTH_ALM1 - DT_SECOND_ALM1 + 1]; + unsigned int val; + int ret; + + ret = regmap_bulk_read(pcf85363->regmap, DT_SECOND_ALM1, buf, + sizeof(buf)); + if (ret) + return ret; + + alrm->time.tm_sec = bcd2bin(buf[0]); + alrm->time.tm_min = bcd2bin(buf[1]); + alrm->time.tm_hour = bcd2bin(buf[2]); + alrm->time.tm_mday = bcd2bin(buf[3]); + alrm->time.tm_mon = bcd2bin(buf[4]) - 1; + + ret = regmap_read(pcf85363->regmap, CTRL_INTA_EN, &val); + if (ret) + return ret; + + alrm->enabled = !!(val & INT_A1IE); + + return 0; +} + +static int _pcf85363_rtc_alarm_irq_enable(struct pcf85363 *pcf85363, unsigned + int enabled) +{ + unsigned int alarm_flags = ALRM_SEC_A1E | ALRM_MIN_A1E | ALRM_HR_A1E | + ALRM_DAY_A1E | ALRM_MON_A1E; + int ret; + + ret = regmap_update_bits(pcf85363->regmap, DT_ALARM_EN, alarm_flags, + enabled ? alarm_flags : 0); + if (ret) + return ret; + + ret = regmap_update_bits(pcf85363->regmap, CTRL_INTA_EN, + INT_A1IE, enabled ? INT_A1IE : 0); + + if (ret || enabled) + return ret; + + /* clear current flags */ + return regmap_update_bits(pcf85363->regmap, CTRL_FLAGS, FLAGS_A1F, 0); +} + +static int pcf85363_rtc_alarm_irq_enable(struct device *dev, + unsigned int enabled) +{ + struct pcf85363 *pcf85363 = dev_get_drvdata(dev); + + return _pcf85363_rtc_alarm_irq_enable(pcf85363, enabled); +} + +static int pcf85363_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct pcf85363 *pcf85363 = dev_get_drvdata(dev); + unsigned char buf[DT_MONTH_ALM1 - DT_SECOND_ALM1 + 1]; + int ret; + + buf[0] = bin2bcd(alrm->time.tm_sec); + buf[1] = bin2bcd(alrm->time.tm_min); + buf[2] = bin2bcd(alrm->time.tm_hour); + buf[3] = bin2bcd(alrm->time.tm_mday); + buf[4] = bin2bcd(alrm->time.tm_mon + 1); + + /* + * Disable the alarm interrupt before changing the value to avoid + * spurious interrupts + */ + ret = _pcf85363_rtc_alarm_irq_enable(pcf85363, 0); + if (ret) + return ret; + + ret = regmap_bulk_write(pcf85363->regmap, DT_SECOND_ALM1, buf, + sizeof(buf)); + if (ret) + return ret; + + return _pcf85363_rtc_alarm_irq_enable(pcf85363, alrm->enabled); +} + +static irqreturn_t pcf85363_rtc_handle_irq(int irq, void *dev_id) +{ + struct pcf85363 *pcf85363 = i2c_get_clientdata(dev_id); + unsigned int flags; + int err; + + err = regmap_read(pcf85363->regmap, CTRL_FLAGS, &flags); + if (err) + return IRQ_NONE; + + if (flags & FLAGS_A1F) { + rtc_update_irq(pcf85363->rtc, 1, RTC_IRQF | RTC_AF); + regmap_update_bits(pcf85363->regmap, CTRL_FLAGS, FLAGS_A1F, 0); + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + +static const struct rtc_class_ops rtc_ops = { + .read_time = pcf85363_rtc_read_time, + .set_time = pcf85363_rtc_set_time, +}; + +static const struct rtc_class_ops rtc_ops_alarm = { + .read_time = pcf85363_rtc_read_time, + .set_time = pcf85363_rtc_set_time, + .read_alarm = pcf85363_rtc_read_alarm, + .set_alarm = pcf85363_rtc_set_alarm, + .alarm_irq_enable = pcf85363_rtc_alarm_irq_enable, +}; + +static int pcf85363_nvram_read(void *priv, unsigned int offset, void *val, + size_t bytes) +{ + struct pcf85363 *pcf85363 = priv; + + return regmap_bulk_read(pcf85363->regmap, CTRL_RAM + offset, + val, bytes); +} + +static int pcf85363_nvram_write(void *priv, unsigned int offset, void *val, + size_t bytes) +{ + struct pcf85363 *pcf85363 = priv; + + return regmap_bulk_write(pcf85363->regmap, CTRL_RAM + offset, + val, bytes); +} + +static const struct regmap_config regmap_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = 0x7f, +}; + +static int pcf85363_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct pcf85363 *pcf85363; + struct nvmem_config nvmem_cfg = { + .name = "pcf85363-", + .word_size = 1, + .stride = 1, + .size = NVRAM_SIZE, + .reg_read = pcf85363_nvram_read, + .reg_write = pcf85363_nvram_write, + }; + int ret; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) + return -ENODEV; + + pcf85363 = devm_kzalloc(&client->dev, sizeof(struct pcf85363), + GFP_KERNEL); + if (!pcf85363) + return -ENOMEM; + + pcf85363->regmap = devm_regmap_init_i2c(client, ®map_config); + if (IS_ERR(pcf85363->regmap)) { + dev_err(&client->dev, "regmap allocation failed\n"); + return PTR_ERR(pcf85363->regmap); + } + + pcf85363->dev = &client->dev; + i2c_set_clientdata(client, pcf85363); + + pcf85363->rtc = devm_rtc_allocate_device(pcf85363->dev); + if (IS_ERR(pcf85363->rtc)) + return PTR_ERR(pcf85363->rtc); + + pcf85363->rtc->ops = &rtc_ops; + + if (client->irq > 0) { + regmap_write(pcf85363->regmap, CTRL_FLAGS, 0); + regmap_update_bits(pcf85363->regmap, CTRL_PIN_IO, + PIN_IO_INTA_OUT, PIN_IO_INTAPM); + ret = devm_request_threaded_irq(pcf85363->dev, client->irq, + NULL, pcf85363_rtc_handle_irq, + IRQF_TRIGGER_LOW | IRQF_ONESHOT, + "pcf85363", client); + if (ret) + dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n"); + else + pcf85363->rtc->ops = &rtc_ops_alarm; + } + + ret = rtc_register_device(pcf85363->rtc); + + nvmem_cfg.priv = pcf85363; + rtc_nvmem_register(pcf85363->rtc, &nvmem_cfg); + + return ret; +} + +static const struct of_device_id dev_ids[] = { + { .compatible = "nxp,pcf85363" }, + {} +}; +MODULE_DEVICE_TABLE(of, dev_ids); + +static struct i2c_driver pcf85363_driver = { + .driver = { + .name = "pcf85363", + .of_match_table = of_match_ptr(dev_ids), + }, + .probe = pcf85363_probe, +}; + +module_i2c_driver(pcf85363_driver); + +MODULE_AUTHOR("Eric Nelson"); +MODULE_DESCRIPTION("pcf85363 I2C RTC driver"); +MODULE_LICENSE("GPL"); |