diff options
Diffstat (limited to 'drivers/rtc/rtc-ds1307.c')
| -rw-r--r-- | drivers/rtc/rtc-ds1307.c | 2021 |
1 files changed, 2021 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c new file mode 100644 index 000000000..d51565bcc --- /dev/null +++ b/drivers/rtc/rtc-ds1307.c @@ -0,0 +1,2021 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * rtc-ds1307.c - RTC driver for some mostly-compatible I2C chips. + * + * Copyright (C) 2005 James Chapman (ds1337 core) + * Copyright (C) 2006 David Brownell + * Copyright (C) 2009 Matthias Fuchs (rx8025 support) + * Copyright (C) 2012 Bertrand Achard (nvram access fixes) + */ + +#include <linux/bcd.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/property.h> +#include <linux/rtc/ds1307.h> +#include <linux/rtc.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/hwmon.h> +#include <linux/hwmon-sysfs.h> +#include <linux/clk-provider.h> +#include <linux/regmap.h> +#include <linux/watchdog.h> + +/* + * We can't determine type by probing, but if we expect pre-Linux code + * to have set the chip up as a clock (turning on the oscillator and + * setting the date and time), Linux can ignore the non-clock features. + * That's a natural job for a factory or repair bench. + */ +enum ds_type { + unknown_ds_type, /* always first and 0 */ + ds_1307, + ds_1308, + ds_1337, + ds_1338, + ds_1339, + ds_1340, + ds_1341, + ds_1388, + ds_3231, + m41t0, + m41t00, + m41t11, + mcp794xx, + rx_8025, + rx_8130, + last_ds_type /* always last */ + /* rs5c372 too? different address... */ +}; + +/* RTC registers don't differ much, except for the century flag */ +#define DS1307_REG_SECS 0x00 /* 00-59 */ +# define DS1307_BIT_CH 0x80 +# define DS1340_BIT_nEOSC 0x80 +# define MCP794XX_BIT_ST 0x80 +#define DS1307_REG_MIN 0x01 /* 00-59 */ +# define M41T0_BIT_OF 0x80 +#define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */ +# define DS1307_BIT_12HR 0x40 /* in REG_HOUR */ +# define DS1307_BIT_PM 0x20 /* in REG_HOUR */ +# define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */ +# define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */ +#define DS1307_REG_WDAY 0x03 /* 01-07 */ +# define MCP794XX_BIT_VBATEN 0x08 +#define DS1307_REG_MDAY 0x04 /* 01-31 */ +#define DS1307_REG_MONTH 0x05 /* 01-12 */ +# define DS1337_BIT_CENTURY 0x80 /* in REG_MONTH */ +#define DS1307_REG_YEAR 0x06 /* 00-99 */ + +/* + * Other registers (control, status, alarms, trickle charge, NVRAM, etc) + * start at 7, and they differ a LOT. Only control and status matter for + * basic RTC date and time functionality; be careful using them. + */ +#define DS1307_REG_CONTROL 0x07 /* or ds1338 */ +# define DS1307_BIT_OUT 0x80 +# define DS1338_BIT_OSF 0x20 +# define DS1307_BIT_SQWE 0x10 +# define DS1307_BIT_RS1 0x02 +# define DS1307_BIT_RS0 0x01 +#define DS1337_REG_CONTROL 0x0e +# define DS1337_BIT_nEOSC 0x80 +# define DS1339_BIT_BBSQI 0x20 +# define DS3231_BIT_BBSQW 0x40 /* same as BBSQI */ +# define DS1337_BIT_RS2 0x10 +# define DS1337_BIT_RS1 0x08 +# define DS1337_BIT_INTCN 0x04 +# define DS1337_BIT_A2IE 0x02 +# define DS1337_BIT_A1IE 0x01 +#define DS1340_REG_CONTROL 0x07 +# define DS1340_BIT_OUT 0x80 +# define DS1340_BIT_FT 0x40 +# define DS1340_BIT_CALIB_SIGN 0x20 +# define DS1340_M_CALIBRATION 0x1f +#define DS1340_REG_FLAG 0x09 +# define DS1340_BIT_OSF 0x80 +#define DS1337_REG_STATUS 0x0f +# define DS1337_BIT_OSF 0x80 +# define DS3231_BIT_EN32KHZ 0x08 +# define DS1337_BIT_A2I 0x02 +# define DS1337_BIT_A1I 0x01 +#define DS1339_REG_ALARM1_SECS 0x07 + +#define DS13XX_TRICKLE_CHARGER_MAGIC 0xa0 + +#define RX8025_REG_CTRL1 0x0e +# define RX8025_BIT_2412 0x20 +#define RX8025_REG_CTRL2 0x0f +# define RX8025_BIT_PON 0x10 +# define RX8025_BIT_VDET 0x40 +# define RX8025_BIT_XST 0x20 + +#define RX8130_REG_ALARM_MIN 0x17 +#define RX8130_REG_ALARM_HOUR 0x18 +#define RX8130_REG_ALARM_WEEK_OR_DAY 0x19 +#define RX8130_REG_EXTENSION 0x1c +#define RX8130_REG_EXTENSION_WADA BIT(3) +#define RX8130_REG_FLAG 0x1d +#define RX8130_REG_FLAG_VLF BIT(1) +#define RX8130_REG_FLAG_AF BIT(3) +#define RX8130_REG_CONTROL0 0x1e +#define RX8130_REG_CONTROL0_AIE BIT(3) +#define RX8130_REG_CONTROL1 0x1f +#define RX8130_REG_CONTROL1_INIEN BIT(4) +#define RX8130_REG_CONTROL1_CHGEN BIT(5) + +#define MCP794XX_REG_CONTROL 0x07 +# define MCP794XX_BIT_ALM0_EN 0x10 +# define MCP794XX_BIT_ALM1_EN 0x20 +#define MCP794XX_REG_ALARM0_BASE 0x0a +#define MCP794XX_REG_ALARM0_CTRL 0x0d +#define MCP794XX_REG_ALARM1_BASE 0x11 +#define MCP794XX_REG_ALARM1_CTRL 0x14 +# define MCP794XX_BIT_ALMX_IF BIT(3) +# define MCP794XX_BIT_ALMX_C0 BIT(4) +# define MCP794XX_BIT_ALMX_C1 BIT(5) +# define MCP794XX_BIT_ALMX_C2 BIT(6) +# define MCP794XX_BIT_ALMX_POL BIT(7) +# define MCP794XX_MSK_ALMX_MATCH (MCP794XX_BIT_ALMX_C0 | \ + MCP794XX_BIT_ALMX_C1 | \ + MCP794XX_BIT_ALMX_C2) + +#define M41TXX_REG_CONTROL 0x07 +# define M41TXX_BIT_OUT BIT(7) +# define M41TXX_BIT_FT BIT(6) +# define M41TXX_BIT_CALIB_SIGN BIT(5) +# define M41TXX_M_CALIBRATION GENMASK(4, 0) + +#define DS1388_REG_WDOG_HUN_SECS 0x08 +#define DS1388_REG_WDOG_SECS 0x09 +#define DS1388_REG_FLAG 0x0b +# define DS1388_BIT_WF BIT(6) +# define DS1388_BIT_OSF BIT(7) +#define DS1388_REG_CONTROL 0x0c +# define DS1388_BIT_RST BIT(0) +# define DS1388_BIT_WDE BIT(1) +# define DS1388_BIT_nEOSC BIT(7) + +/* negative offset step is -2.034ppm */ +#define M41TXX_NEG_OFFSET_STEP_PPB 2034 +/* positive offset step is +4.068ppm */ +#define M41TXX_POS_OFFSET_STEP_PPB 4068 +/* Min and max values supported with 'offset' interface by M41TXX */ +#define M41TXX_MIN_OFFSET ((-31) * M41TXX_NEG_OFFSET_STEP_PPB) +#define M41TXX_MAX_OFFSET ((31) * M41TXX_POS_OFFSET_STEP_PPB) + +struct ds1307 { + enum ds_type type; + struct device *dev; + struct regmap *regmap; + const char *name; + struct rtc_device *rtc; +#ifdef CONFIG_COMMON_CLK + struct clk_hw clks[2]; +#endif +}; + +struct chip_desc { + unsigned alarm:1; + u16 nvram_offset; + u16 nvram_size; + u8 offset; /* register's offset */ + u8 century_reg; + u8 century_enable_bit; + u8 century_bit; + u8 bbsqi_bit; + irq_handler_t irq_handler; + const struct rtc_class_ops *rtc_ops; + u16 trickle_charger_reg; + u8 (*do_trickle_setup)(struct ds1307 *, u32, + bool); + /* Does the RTC require trickle-resistor-ohms to select the value of + * the resistor between Vcc and Vbackup? + */ + bool requires_trickle_resistor; + /* Some RTC's batteries and supercaps were charged by default, others + * allow charging but were not configured previously to do so. + * Remember this behavior to stay backwards compatible. + */ + bool charge_default; +}; + +static const struct chip_desc chips[last_ds_type]; + +static int ds1307_get_time(struct device *dev, struct rtc_time *t) +{ + struct ds1307 *ds1307 = dev_get_drvdata(dev); + int tmp, ret; + const struct chip_desc *chip = &chips[ds1307->type]; + u8 regs[7]; + + if (ds1307->type == rx_8130) { + unsigned int regflag; + ret = regmap_read(ds1307->regmap, RX8130_REG_FLAG, ®flag); + if (ret) { + dev_err(dev, "%s error %d\n", "read", ret); + return ret; + } + + if (regflag & RX8130_REG_FLAG_VLF) { + dev_warn_once(dev, "oscillator failed, set time!\n"); + return -EINVAL; + } + } + + /* read the RTC date and time registers all at once */ + ret = regmap_bulk_read(ds1307->regmap, chip->offset, regs, + sizeof(regs)); + if (ret) { + dev_err(dev, "%s error %d\n", "read", ret); + return ret; + } + + dev_dbg(dev, "%s: %7ph\n", "read", regs); + + /* if oscillator fail bit is set, no data can be trusted */ + if (ds1307->type == m41t0 && + regs[DS1307_REG_MIN] & M41T0_BIT_OF) { + dev_warn_once(dev, "oscillator failed, set time!\n"); + return -EINVAL; + } + + tmp = regs[DS1307_REG_SECS]; + switch (ds1307->type) { + case ds_1307: + case m41t0: + case m41t00: + case m41t11: + if (tmp & DS1307_BIT_CH) + return -EINVAL; + break; + case ds_1308: + case ds_1338: + if (tmp & DS1307_BIT_CH) + return -EINVAL; + + ret = regmap_read(ds1307->regmap, DS1307_REG_CONTROL, &tmp); + if (ret) + return ret; + if (tmp & DS1338_BIT_OSF) + return -EINVAL; + break; + case ds_1340: + if (tmp & DS1340_BIT_nEOSC) + return -EINVAL; + + ret = regmap_read(ds1307->regmap, DS1340_REG_FLAG, &tmp); + if (ret) + return ret; + if (tmp & DS1340_BIT_OSF) + return -EINVAL; + break; + case ds_1388: + ret = regmap_read(ds1307->regmap, DS1388_REG_FLAG, &tmp); + if (ret) + return ret; + if (tmp & DS1388_BIT_OSF) + return -EINVAL; + break; + case mcp794xx: + if (!(tmp & MCP794XX_BIT_ST)) + return -EINVAL; + + break; + default: + break; + } + + t->tm_sec = bcd2bin(regs[DS1307_REG_SECS] & 0x7f); + t->tm_min = bcd2bin(regs[DS1307_REG_MIN] & 0x7f); + tmp = regs[DS1307_REG_HOUR] & 0x3f; + t->tm_hour = bcd2bin(tmp); + /* rx8130 is bit position, not BCD */ + if (ds1307->type == rx_8130) + t->tm_wday = fls(regs[DS1307_REG_WDAY] & 0x7f); + else + t->tm_wday = bcd2bin(regs[DS1307_REG_WDAY] & 0x07) - 1; + t->tm_mday = bcd2bin(regs[DS1307_REG_MDAY] & 0x3f); + tmp = regs[DS1307_REG_MONTH] & 0x1f; + t->tm_mon = bcd2bin(tmp) - 1; + t->tm_year = bcd2bin(regs[DS1307_REG_YEAR]) + 100; + + if (regs[chip->century_reg] & chip->century_bit && + IS_ENABLED(CONFIG_RTC_DRV_DS1307_CENTURY)) + t->tm_year += 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 ds1307_set_time(struct device *dev, struct rtc_time *t) +{ + struct ds1307 *ds1307 = dev_get_drvdata(dev); + const struct chip_desc *chip = &chips[ds1307->type]; + int result; + int tmp; + u8 regs[7]; + + 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); + + if (t->tm_year < 100) + return -EINVAL; + +#ifdef CONFIG_RTC_DRV_DS1307_CENTURY + if (t->tm_year > (chip->century_bit ? 299 : 199)) + return -EINVAL; +#else + if (t->tm_year > 199) + return -EINVAL; +#endif + + regs[DS1307_REG_SECS] = bin2bcd(t->tm_sec); + regs[DS1307_REG_MIN] = bin2bcd(t->tm_min); + regs[DS1307_REG_HOUR] = bin2bcd(t->tm_hour); + /* rx8130 is bit position, not BCD */ + if (ds1307->type == rx_8130) + regs[DS1307_REG_WDAY] = 1 << t->tm_wday; + else + regs[DS1307_REG_WDAY] = bin2bcd(t->tm_wday + 1); + regs[DS1307_REG_MDAY] = bin2bcd(t->tm_mday); + regs[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1); + + /* assume 20YY not 19YY */ + tmp = t->tm_year - 100; + regs[DS1307_REG_YEAR] = bin2bcd(tmp); + + if (chip->century_enable_bit) + regs[chip->century_reg] |= chip->century_enable_bit; + if (t->tm_year > 199 && chip->century_bit) + regs[chip->century_reg] |= chip->century_bit; + + switch (ds1307->type) { + case ds_1308: + case ds_1338: + regmap_update_bits(ds1307->regmap, DS1307_REG_CONTROL, + DS1338_BIT_OSF, 0); + break; + case ds_1340: + regmap_update_bits(ds1307->regmap, DS1340_REG_FLAG, + DS1340_BIT_OSF, 0); + break; + case ds_1388: + regmap_update_bits(ds1307->regmap, DS1388_REG_FLAG, + DS1388_BIT_OSF, 0); + break; + case mcp794xx: + /* + * these bits were cleared when preparing the date/time + * values and need to be set again before writing the + * regsfer out to the device. + */ + regs[DS1307_REG_SECS] |= MCP794XX_BIT_ST; + regs[DS1307_REG_WDAY] |= MCP794XX_BIT_VBATEN; + break; + default: + break; + } + + dev_dbg(dev, "%s: %7ph\n", "write", regs); + + result = regmap_bulk_write(ds1307->regmap, chip->offset, regs, + sizeof(regs)); + if (result) { + dev_err(dev, "%s error %d\n", "write", result); + return result; + } + + if (ds1307->type == rx_8130) { + /* clear Voltage Loss Flag as data is available now */ + result = regmap_write(ds1307->regmap, RX8130_REG_FLAG, + ~(u8)RX8130_REG_FLAG_VLF); + if (result) { + dev_err(dev, "%s error %d\n", "write", result); + return result; + } + } + + return 0; +} + +static int ds1337_read_alarm(struct device *dev, struct rtc_wkalrm *t) +{ + struct ds1307 *ds1307 = dev_get_drvdata(dev); + int ret; + u8 regs[9]; + + /* read all ALARM1, ALARM2, and status registers at once */ + ret = regmap_bulk_read(ds1307->regmap, DS1339_REG_ALARM1_SECS, + regs, sizeof(regs)); + if (ret) { + dev_err(dev, "%s error %d\n", "alarm read", ret); + return ret; + } + + dev_dbg(dev, "%s: %4ph, %3ph, %2ph\n", "alarm read", + ®s[0], ®s[4], ®s[7]); + + /* + * report alarm time (ALARM1); assume 24 hour and day-of-month modes, + * and that all four fields are checked matches + */ + t->time.tm_sec = bcd2bin(regs[0] & 0x7f); + t->time.tm_min = bcd2bin(regs[1] & 0x7f); + t->time.tm_hour = bcd2bin(regs[2] & 0x3f); + t->time.tm_mday = bcd2bin(regs[3] & 0x3f); + + /* ... and status */ + t->enabled = !!(regs[7] & DS1337_BIT_A1IE); + t->pending = !!(regs[8] & DS1337_BIT_A1I); + + dev_dbg(dev, "%s secs=%d, mins=%d, " + "hours=%d, mday=%d, enabled=%d, pending=%d\n", + "alarm read", t->time.tm_sec, t->time.tm_min, + t->time.tm_hour, t->time.tm_mday, + t->enabled, t->pending); + + return 0; +} + +static int ds1337_set_alarm(struct device *dev, struct rtc_wkalrm *t) +{ + struct ds1307 *ds1307 = dev_get_drvdata(dev); + unsigned char regs[9]; + u8 control, status; + int ret; + + dev_dbg(dev, "%s secs=%d, mins=%d, " + "hours=%d, mday=%d, enabled=%d, pending=%d\n", + "alarm set", t->time.tm_sec, t->time.tm_min, + t->time.tm_hour, t->time.tm_mday, + t->enabled, t->pending); + + /* read current status of both alarms and the chip */ + ret = regmap_bulk_read(ds1307->regmap, DS1339_REG_ALARM1_SECS, regs, + sizeof(regs)); + if (ret) { + dev_err(dev, "%s error %d\n", "alarm write", ret); + return ret; + } + control = regs[7]; + status = regs[8]; + + dev_dbg(dev, "%s: %4ph, %3ph, %02x %02x\n", "alarm set (old status)", + ®s[0], ®s[4], control, status); + + /* set ALARM1, using 24 hour and day-of-month modes */ + regs[0] = bin2bcd(t->time.tm_sec); + regs[1] = bin2bcd(t->time.tm_min); + regs[2] = bin2bcd(t->time.tm_hour); + regs[3] = bin2bcd(t->time.tm_mday); + + /* set ALARM2 to non-garbage */ + regs[4] = 0; + regs[5] = 0; + regs[6] = 0; + + /* disable alarms */ + regs[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE); + regs[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I); + + ret = regmap_bulk_write(ds1307->regmap, DS1339_REG_ALARM1_SECS, regs, + sizeof(regs)); + if (ret) { + dev_err(dev, "can't set alarm time\n"); + return ret; + } + + /* optionally enable ALARM1 */ + if (t->enabled) { + dev_dbg(dev, "alarm IRQ armed\n"); + regs[7] |= DS1337_BIT_A1IE; /* only ALARM1 is used */ + regmap_write(ds1307->regmap, DS1337_REG_CONTROL, regs[7]); + } + + return 0; +} + +static int ds1307_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct ds1307 *ds1307 = dev_get_drvdata(dev); + + return regmap_update_bits(ds1307->regmap, DS1337_REG_CONTROL, + DS1337_BIT_A1IE, + enabled ? DS1337_BIT_A1IE : 0); +} + +static u8 do_trickle_setup_ds1339(struct ds1307 *ds1307, u32 ohms, bool diode) +{ + u8 setup = (diode) ? DS1307_TRICKLE_CHARGER_DIODE : + DS1307_TRICKLE_CHARGER_NO_DIODE; + + setup |= DS13XX_TRICKLE_CHARGER_MAGIC; + + switch (ohms) { + case 250: + setup |= DS1307_TRICKLE_CHARGER_250_OHM; + break; + case 2000: + setup |= DS1307_TRICKLE_CHARGER_2K_OHM; + break; + case 4000: + setup |= DS1307_TRICKLE_CHARGER_4K_OHM; + break; + default: + dev_warn(ds1307->dev, + "Unsupported ohm value %u in dt\n", ohms); + return 0; + } + return setup; +} + +static u8 do_trickle_setup_rx8130(struct ds1307 *ds1307, u32 ohms, bool diode) +{ + /* make sure that the backup battery is enabled */ + u8 setup = RX8130_REG_CONTROL1_INIEN; + if (diode) + setup |= RX8130_REG_CONTROL1_CHGEN; + + return setup; +} + +static irqreturn_t rx8130_irq(int irq, void *dev_id) +{ + struct ds1307 *ds1307 = dev_id; + u8 ctl[3]; + int ret; + + rtc_lock(ds1307->rtc); + + /* Read control registers. */ + ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_EXTENSION, ctl, + sizeof(ctl)); + if (ret < 0) + goto out; + if (!(ctl[1] & RX8130_REG_FLAG_AF)) + goto out; + ctl[1] &= ~RX8130_REG_FLAG_AF; + ctl[2] &= ~RX8130_REG_CONTROL0_AIE; + + ret = regmap_bulk_write(ds1307->regmap, RX8130_REG_EXTENSION, ctl, + sizeof(ctl)); + if (ret < 0) + goto out; + + rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF); + +out: + rtc_unlock(ds1307->rtc); + + return IRQ_HANDLED; +} + +static int rx8130_read_alarm(struct device *dev, struct rtc_wkalrm *t) +{ + struct ds1307 *ds1307 = dev_get_drvdata(dev); + u8 ald[3], ctl[3]; + int ret; + + /* Read alarm registers. */ + ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_ALARM_MIN, ald, + sizeof(ald)); + if (ret < 0) + return ret; + + /* Read control registers. */ + ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_EXTENSION, ctl, + sizeof(ctl)); + if (ret < 0) + return ret; + + t->enabled = !!(ctl[2] & RX8130_REG_CONTROL0_AIE); + t->pending = !!(ctl[1] & RX8130_REG_FLAG_AF); + + /* Report alarm 0 time assuming 24-hour and day-of-month modes. */ + t->time.tm_sec = -1; + t->time.tm_min = bcd2bin(ald[0] & 0x7f); + t->time.tm_hour = bcd2bin(ald[1] & 0x7f); + t->time.tm_wday = -1; + t->time.tm_mday = bcd2bin(ald[2] & 0x7f); + t->time.tm_mon = -1; + t->time.tm_year = -1; + t->time.tm_yday = -1; + t->time.tm_isdst = -1; + + dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d enabled=%d\n", + __func__, t->time.tm_sec, t->time.tm_min, t->time.tm_hour, + t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled); + + return 0; +} + +static int rx8130_set_alarm(struct device *dev, struct rtc_wkalrm *t) +{ + struct ds1307 *ds1307 = dev_get_drvdata(dev); + u8 ald[3], ctl[3]; + int ret; + + dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d " + "enabled=%d pending=%d\n", __func__, + t->time.tm_sec, t->time.tm_min, t->time.tm_hour, + t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, + t->enabled, t->pending); + + /* Read control registers. */ + ret = regmap_bulk_read(ds1307->regmap, RX8130_REG_EXTENSION, ctl, + sizeof(ctl)); + if (ret < 0) + return ret; + + ctl[0] &= RX8130_REG_EXTENSION_WADA; + ctl[1] &= ~RX8130_REG_FLAG_AF; + ctl[2] &= ~RX8130_REG_CONTROL0_AIE; + + ret = regmap_bulk_write(ds1307->regmap, RX8130_REG_EXTENSION, ctl, + sizeof(ctl)); + if (ret < 0) + return ret; + + /* Hardware alarm precision is 1 minute! */ + ald[0] = bin2bcd(t->time.tm_min); + ald[1] = bin2bcd(t->time.tm_hour); + ald[2] = bin2bcd(t->time.tm_mday); + + ret = regmap_bulk_write(ds1307->regmap, RX8130_REG_ALARM_MIN, ald, + sizeof(ald)); + if (ret < 0) + return ret; + + if (!t->enabled) + return 0; + + ctl[2] |= RX8130_REG_CONTROL0_AIE; + + return regmap_write(ds1307->regmap, RX8130_REG_CONTROL0, ctl[2]); +} + +static int rx8130_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct ds1307 *ds1307 = dev_get_drvdata(dev); + int ret, reg; + + ret = regmap_read(ds1307->regmap, RX8130_REG_CONTROL0, ®); + if (ret < 0) + return ret; + + if (enabled) + reg |= RX8130_REG_CONTROL0_AIE; + else + reg &= ~RX8130_REG_CONTROL0_AIE; + + return regmap_write(ds1307->regmap, RX8130_REG_CONTROL0, reg); +} + +static irqreturn_t mcp794xx_irq(int irq, void *dev_id) +{ + struct ds1307 *ds1307 = dev_id; + struct mutex *lock = &ds1307->rtc->ops_lock; + int reg, ret; + + mutex_lock(lock); + + /* Check and clear alarm 0 interrupt flag. */ + ret = regmap_read(ds1307->regmap, MCP794XX_REG_ALARM0_CTRL, ®); + if (ret) + goto out; + if (!(reg & MCP794XX_BIT_ALMX_IF)) + goto out; + reg &= ~MCP794XX_BIT_ALMX_IF; + ret = regmap_write(ds1307->regmap, MCP794XX_REG_ALARM0_CTRL, reg); + if (ret) + goto out; + + /* Disable alarm 0. */ + ret = regmap_update_bits(ds1307->regmap, MCP794XX_REG_CONTROL, + MCP794XX_BIT_ALM0_EN, 0); + if (ret) + goto out; + + rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF); + +out: + mutex_unlock(lock); + + return IRQ_HANDLED; +} + +static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t) +{ + struct ds1307 *ds1307 = dev_get_drvdata(dev); + u8 regs[10]; + int ret; + + /* Read control and alarm 0 registers. */ + ret = regmap_bulk_read(ds1307->regmap, MCP794XX_REG_CONTROL, regs, + sizeof(regs)); + if (ret) + return ret; + + t->enabled = !!(regs[0] & MCP794XX_BIT_ALM0_EN); + + /* Report alarm 0 time assuming 24-hour and day-of-month modes. */ + t->time.tm_sec = bcd2bin(regs[3] & 0x7f); + t->time.tm_min = bcd2bin(regs[4] & 0x7f); + t->time.tm_hour = bcd2bin(regs[5] & 0x3f); + t->time.tm_wday = bcd2bin(regs[6] & 0x7) - 1; + t->time.tm_mday = bcd2bin(regs[7] & 0x3f); + t->time.tm_mon = bcd2bin(regs[8] & 0x1f) - 1; + t->time.tm_year = -1; + t->time.tm_yday = -1; + t->time.tm_isdst = -1; + + dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d " + "enabled=%d polarity=%d irq=%d match=%lu\n", __func__, + t->time.tm_sec, t->time.tm_min, t->time.tm_hour, + t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled, + !!(regs[6] & MCP794XX_BIT_ALMX_POL), + !!(regs[6] & MCP794XX_BIT_ALMX_IF), + (regs[6] & MCP794XX_MSK_ALMX_MATCH) >> 4); + + return 0; +} + +/* + * We may have a random RTC weekday, therefore calculate alarm weekday based + * on current weekday we read from the RTC timekeeping regs + */ +static int mcp794xx_alm_weekday(struct device *dev, struct rtc_time *tm_alarm) +{ + struct rtc_time tm_now; + int days_now, days_alarm, ret; + + ret = ds1307_get_time(dev, &tm_now); + if (ret) + return ret; + + days_now = div_s64(rtc_tm_to_time64(&tm_now), 24 * 60 * 60); + days_alarm = div_s64(rtc_tm_to_time64(tm_alarm), 24 * 60 * 60); + + return (tm_now.tm_wday + days_alarm - days_now) % 7 + 1; +} + +static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t) +{ + struct ds1307 *ds1307 = dev_get_drvdata(dev); + unsigned char regs[10]; + int wday, ret; + + wday = mcp794xx_alm_weekday(dev, &t->time); + if (wday < 0) + return wday; + + dev_dbg(dev, "%s, sec=%d min=%d hour=%d wday=%d mday=%d mon=%d " + "enabled=%d pending=%d\n", __func__, + t->time.tm_sec, t->time.tm_min, t->time.tm_hour, + t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, + t->enabled, t->pending); + + /* Read control and alarm 0 registers. */ + ret = regmap_bulk_read(ds1307->regmap, MCP794XX_REG_CONTROL, regs, + sizeof(regs)); + if (ret) + return ret; + + /* Set alarm 0, using 24-hour and day-of-month modes. */ + regs[3] = bin2bcd(t->time.tm_sec); + regs[4] = bin2bcd(t->time.tm_min); + regs[5] = bin2bcd(t->time.tm_hour); + regs[6] = wday; + regs[7] = bin2bcd(t->time.tm_mday); + regs[8] = bin2bcd(t->time.tm_mon + 1); + + /* Clear the alarm 0 interrupt flag. */ + regs[6] &= ~MCP794XX_BIT_ALMX_IF; + /* Set alarm match: second, minute, hour, day, date, month. */ + regs[6] |= MCP794XX_MSK_ALMX_MATCH; + /* Disable interrupt. We will not enable until completely programmed */ + regs[0] &= ~MCP794XX_BIT_ALM0_EN; + + ret = regmap_bulk_write(ds1307->regmap, MCP794XX_REG_CONTROL, regs, + sizeof(regs)); + if (ret) + return ret; + + if (!t->enabled) + return 0; + regs[0] |= MCP794XX_BIT_ALM0_EN; + return regmap_write(ds1307->regmap, MCP794XX_REG_CONTROL, regs[0]); +} + +static int mcp794xx_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct ds1307 *ds1307 = dev_get_drvdata(dev); + + return regmap_update_bits(ds1307->regmap, MCP794XX_REG_CONTROL, + MCP794XX_BIT_ALM0_EN, + enabled ? MCP794XX_BIT_ALM0_EN : 0); +} + +static int m41txx_rtc_read_offset(struct device *dev, long *offset) +{ + struct ds1307 *ds1307 = dev_get_drvdata(dev); + unsigned int ctrl_reg; + u8 val; + + regmap_read(ds1307->regmap, M41TXX_REG_CONTROL, &ctrl_reg); + + val = ctrl_reg & M41TXX_M_CALIBRATION; + + /* check if positive */ + if (ctrl_reg & M41TXX_BIT_CALIB_SIGN) + *offset = (val * M41TXX_POS_OFFSET_STEP_PPB); + else + *offset = -(val * M41TXX_NEG_OFFSET_STEP_PPB); + + return 0; +} + +static int m41txx_rtc_set_offset(struct device *dev, long offset) +{ + struct ds1307 *ds1307 = dev_get_drvdata(dev); + unsigned int ctrl_reg; + + if ((offset < M41TXX_MIN_OFFSET) || (offset > M41TXX_MAX_OFFSET)) + return -ERANGE; + + if (offset >= 0) { + ctrl_reg = DIV_ROUND_CLOSEST(offset, + M41TXX_POS_OFFSET_STEP_PPB); + ctrl_reg |= M41TXX_BIT_CALIB_SIGN; + } else { + ctrl_reg = DIV_ROUND_CLOSEST(abs(offset), + M41TXX_NEG_OFFSET_STEP_PPB); + } + + return regmap_update_bits(ds1307->regmap, M41TXX_REG_CONTROL, + M41TXX_M_CALIBRATION | M41TXX_BIT_CALIB_SIGN, + ctrl_reg); +} + +#ifdef CONFIG_WATCHDOG_CORE +static int ds1388_wdt_start(struct watchdog_device *wdt_dev) +{ + struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev); + u8 regs[2]; + int ret; + + ret = regmap_update_bits(ds1307->regmap, DS1388_REG_FLAG, + DS1388_BIT_WF, 0); + if (ret) + return ret; + + ret = regmap_update_bits(ds1307->regmap, DS1388_REG_CONTROL, + DS1388_BIT_WDE | DS1388_BIT_RST, 0); + if (ret) + return ret; + + /* + * watchdog timeouts are measured in seconds. So ignore hundredths of + * seconds field. + */ + regs[0] = 0; + regs[1] = bin2bcd(wdt_dev->timeout); + + ret = regmap_bulk_write(ds1307->regmap, DS1388_REG_WDOG_HUN_SECS, regs, + sizeof(regs)); + if (ret) + return ret; + + return regmap_update_bits(ds1307->regmap, DS1388_REG_CONTROL, + DS1388_BIT_WDE | DS1388_BIT_RST, + DS1388_BIT_WDE | DS1388_BIT_RST); +} + +static int ds1388_wdt_stop(struct watchdog_device *wdt_dev) +{ + struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev); + + return regmap_update_bits(ds1307->regmap, DS1388_REG_CONTROL, + DS1388_BIT_WDE | DS1388_BIT_RST, 0); +} + +static int ds1388_wdt_ping(struct watchdog_device *wdt_dev) +{ + struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev); + u8 regs[2]; + + return regmap_bulk_read(ds1307->regmap, DS1388_REG_WDOG_HUN_SECS, regs, + sizeof(regs)); +} + +static int ds1388_wdt_set_timeout(struct watchdog_device *wdt_dev, + unsigned int val) +{ + struct ds1307 *ds1307 = watchdog_get_drvdata(wdt_dev); + u8 regs[2]; + + wdt_dev->timeout = val; + regs[0] = 0; + regs[1] = bin2bcd(wdt_dev->timeout); + + return regmap_bulk_write(ds1307->regmap, DS1388_REG_WDOG_HUN_SECS, regs, + sizeof(regs)); +} +#endif + +static const struct rtc_class_ops rx8130_rtc_ops = { + .read_time = ds1307_get_time, + .set_time = ds1307_set_time, + .read_alarm = rx8130_read_alarm, + .set_alarm = rx8130_set_alarm, + .alarm_irq_enable = rx8130_alarm_irq_enable, +}; + +static const struct rtc_class_ops mcp794xx_rtc_ops = { + .read_time = ds1307_get_time, + .set_time = ds1307_set_time, + .read_alarm = mcp794xx_read_alarm, + .set_alarm = mcp794xx_set_alarm, + .alarm_irq_enable = mcp794xx_alarm_irq_enable, +}; + +static const struct rtc_class_ops m41txx_rtc_ops = { + .read_time = ds1307_get_time, + .set_time = ds1307_set_time, + .read_alarm = ds1337_read_alarm, + .set_alarm = ds1337_set_alarm, + .alarm_irq_enable = ds1307_alarm_irq_enable, + .read_offset = m41txx_rtc_read_offset, + .set_offset = m41txx_rtc_set_offset, +}; + +static const struct chip_desc chips[last_ds_type] = { + [ds_1307] = { + .nvram_offset = 8, + .nvram_size = 56, + }, + [ds_1308] = { + .nvram_offset = 8, + .nvram_size = 56, + }, + [ds_1337] = { + .alarm = 1, + .century_reg = DS1307_REG_MONTH, + .century_bit = DS1337_BIT_CENTURY, + }, + [ds_1338] = { + .nvram_offset = 8, + .nvram_size = 56, + }, + [ds_1339] = { + .alarm = 1, + .century_reg = DS1307_REG_MONTH, + .century_bit = DS1337_BIT_CENTURY, + .bbsqi_bit = DS1339_BIT_BBSQI, + .trickle_charger_reg = 0x10, + .do_trickle_setup = &do_trickle_setup_ds1339, + .requires_trickle_resistor = true, + .charge_default = true, + }, + [ds_1340] = { + .century_reg = DS1307_REG_HOUR, + .century_enable_bit = DS1340_BIT_CENTURY_EN, + .century_bit = DS1340_BIT_CENTURY, + .do_trickle_setup = &do_trickle_setup_ds1339, + .trickle_charger_reg = 0x08, + .requires_trickle_resistor = true, + .charge_default = true, + }, + [ds_1341] = { + .century_reg = DS1307_REG_MONTH, + .century_bit = DS1337_BIT_CENTURY, + }, + [ds_1388] = { + .offset = 1, + .trickle_charger_reg = 0x0a, + }, + [ds_3231] = { + .alarm = 1, + .century_reg = DS1307_REG_MONTH, + .century_bit = DS1337_BIT_CENTURY, + .bbsqi_bit = DS3231_BIT_BBSQW, + }, + [rx_8130] = { + .alarm = 1, + /* this is battery backed SRAM */ + .nvram_offset = 0x20, + .nvram_size = 4, /* 32bit (4 word x 8 bit) */ + .offset = 0x10, + .irq_handler = rx8130_irq, + .rtc_ops = &rx8130_rtc_ops, + .trickle_charger_reg = RX8130_REG_CONTROL1, + .do_trickle_setup = &do_trickle_setup_rx8130, + }, + [m41t0] = { + .rtc_ops = &m41txx_rtc_ops, + }, + [m41t00] = { + .rtc_ops = &m41txx_rtc_ops, + }, + [m41t11] = { + /* this is battery backed SRAM */ + .nvram_offset = 8, + .nvram_size = 56, + .rtc_ops = &m41txx_rtc_ops, + }, + [mcp794xx] = { + .alarm = 1, + /* this is battery backed SRAM */ + .nvram_offset = 0x20, + .nvram_size = 0x40, + .irq_handler = mcp794xx_irq, + .rtc_ops = &mcp794xx_rtc_ops, + }, +}; + +static const struct i2c_device_id ds1307_id[] = { + { "ds1307", ds_1307 }, + { "ds1308", ds_1308 }, + { "ds1337", ds_1337 }, + { "ds1338", ds_1338 }, + { "ds1339", ds_1339 }, + { "ds1388", ds_1388 }, + { "ds1340", ds_1340 }, + { "ds1341", ds_1341 }, + { "ds3231", ds_3231 }, + { "m41t0", m41t0 }, + { "m41t00", m41t00 }, + { "m41t11", m41t11 }, + { "mcp7940x", mcp794xx }, + { "mcp7941x", mcp794xx }, + { "pt7c4338", ds_1307 }, + { "rx8025", rx_8025 }, + { "isl12057", ds_1337 }, + { "rx8130", rx_8130 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, ds1307_id); + +static const struct of_device_id ds1307_of_match[] = { + { + .compatible = "dallas,ds1307", + .data = (void *)ds_1307 + }, + { + .compatible = "dallas,ds1308", + .data = (void *)ds_1308 + }, + { + .compatible = "dallas,ds1337", + .data = (void *)ds_1337 + }, + { + .compatible = "dallas,ds1338", + .data = (void *)ds_1338 + }, + { + .compatible = "dallas,ds1339", + .data = (void *)ds_1339 + }, + { + .compatible = "dallas,ds1388", + .data = (void *)ds_1388 + }, + { + .compatible = "dallas,ds1340", + .data = (void *)ds_1340 + }, + { + .compatible = "dallas,ds1341", + .data = (void *)ds_1341 + }, + { + .compatible = "maxim,ds3231", + .data = (void *)ds_3231 + }, + { + .compatible = "st,m41t0", + .data = (void *)m41t0 + }, + { + .compatible = "st,m41t00", + .data = (void *)m41t00 + }, + { + .compatible = "st,m41t11", + .data = (void *)m41t11 + }, + { + .compatible = "microchip,mcp7940x", + .data = (void *)mcp794xx + }, + { + .compatible = "microchip,mcp7941x", + .data = (void *)mcp794xx + }, + { + .compatible = "pericom,pt7c4338", + .data = (void *)ds_1307 + }, + { + .compatible = "epson,rx8025", + .data = (void *)rx_8025 + }, + { + .compatible = "isil,isl12057", + .data = (void *)ds_1337 + }, + { + .compatible = "epson,rx8130", + .data = (void *)rx_8130 + }, + { } +}; +MODULE_DEVICE_TABLE(of, ds1307_of_match); + +/* + * The ds1337 and ds1339 both have two alarms, but we only use the first + * one (with a "seconds" field). For ds1337 we expect nINTA is our alarm + * signal; ds1339 chips have only one alarm signal. + */ +static irqreturn_t ds1307_irq(int irq, void *dev_id) +{ + struct ds1307 *ds1307 = dev_id; + struct mutex *lock = &ds1307->rtc->ops_lock; + int stat, ret; + + mutex_lock(lock); + ret = regmap_read(ds1307->regmap, DS1337_REG_STATUS, &stat); + if (ret) + goto out; + + if (stat & DS1337_BIT_A1I) { + stat &= ~DS1337_BIT_A1I; + regmap_write(ds1307->regmap, DS1337_REG_STATUS, stat); + + ret = regmap_update_bits(ds1307->regmap, DS1337_REG_CONTROL, + DS1337_BIT_A1IE, 0); + if (ret) + goto out; + + rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF); + } + +out: + mutex_unlock(lock); + + return IRQ_HANDLED; +} + +/*----------------------------------------------------------------------*/ + +static const struct rtc_class_ops ds13xx_rtc_ops = { + .read_time = ds1307_get_time, + .set_time = ds1307_set_time, + .read_alarm = ds1337_read_alarm, + .set_alarm = ds1337_set_alarm, + .alarm_irq_enable = ds1307_alarm_irq_enable, +}; + +static ssize_t frequency_test_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct ds1307 *ds1307 = dev_get_drvdata(dev->parent); + bool freq_test_en; + int ret; + + ret = kstrtobool(buf, &freq_test_en); + if (ret) { + dev_err(dev, "Failed to store RTC Frequency Test attribute\n"); + return ret; + } + + regmap_update_bits(ds1307->regmap, M41TXX_REG_CONTROL, M41TXX_BIT_FT, + freq_test_en ? M41TXX_BIT_FT : 0); + + return count; +} + +static ssize_t frequency_test_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct ds1307 *ds1307 = dev_get_drvdata(dev->parent); + unsigned int ctrl_reg; + + regmap_read(ds1307->regmap, M41TXX_REG_CONTROL, &ctrl_reg); + + return scnprintf(buf, PAGE_SIZE, (ctrl_reg & M41TXX_BIT_FT) ? "on\n" : + "off\n"); +} + +static DEVICE_ATTR_RW(frequency_test); + +static struct attribute *rtc_freq_test_attrs[] = { + &dev_attr_frequency_test.attr, + NULL, +}; + +static const struct attribute_group rtc_freq_test_attr_group = { + .attrs = rtc_freq_test_attrs, +}; + +static int ds1307_add_frequency_test(struct ds1307 *ds1307) +{ + int err; + + switch (ds1307->type) { + case m41t0: + case m41t00: + case m41t11: + err = rtc_add_group(ds1307->rtc, &rtc_freq_test_attr_group); + if (err) + return err; + break; + default: + break; + } + + return 0; +} + +/*----------------------------------------------------------------------*/ + +static int ds1307_nvram_read(void *priv, unsigned int offset, void *val, + size_t bytes) +{ + struct ds1307 *ds1307 = priv; + const struct chip_desc *chip = &chips[ds1307->type]; + + return regmap_bulk_read(ds1307->regmap, chip->nvram_offset + offset, + val, bytes); +} + +static int ds1307_nvram_write(void *priv, unsigned int offset, void *val, + size_t bytes) +{ + struct ds1307 *ds1307 = priv; + const struct chip_desc *chip = &chips[ds1307->type]; + + return regmap_bulk_write(ds1307->regmap, chip->nvram_offset + offset, + val, bytes); +} + +/*----------------------------------------------------------------------*/ + +static u8 ds1307_trickle_init(struct ds1307 *ds1307, + const struct chip_desc *chip) +{ + u32 ohms, chargeable; + bool diode = chip->charge_default; + + if (!chip->do_trickle_setup) + return 0; + + if (device_property_read_u32(ds1307->dev, "trickle-resistor-ohms", + &ohms) && chip->requires_trickle_resistor) + return 0; + + /* aux-voltage-chargeable takes precedence over the deprecated + * trickle-diode-disable + */ + if (!device_property_read_u32(ds1307->dev, "aux-voltage-chargeable", + &chargeable)) { + switch (chargeable) { + case 0: + diode = false; + break; + case 1: + diode = true; + break; + default: + dev_warn(ds1307->dev, + "unsupported aux-voltage-chargeable value\n"); + break; + } + } else if (device_property_read_bool(ds1307->dev, + "trickle-diode-disable")) { + diode = false; + } + + return chip->do_trickle_setup(ds1307, ohms, diode); +} + +/*----------------------------------------------------------------------*/ + +#if IS_REACHABLE(CONFIG_HWMON) + +/* + * Temperature sensor support for ds3231 devices. + */ + +#define DS3231_REG_TEMPERATURE 0x11 + +/* + * A user-initiated temperature conversion is not started by this function, + * so the temperature is updated once every 64 seconds. + */ +static int ds3231_hwmon_read_temp(struct device *dev, s32 *mC) +{ + struct ds1307 *ds1307 = dev_get_drvdata(dev); + u8 temp_buf[2]; + s16 temp; + int ret; + + ret = regmap_bulk_read(ds1307->regmap, DS3231_REG_TEMPERATURE, + temp_buf, sizeof(temp_buf)); + if (ret) + return ret; + /* + * Temperature is represented as a 10-bit code with a resolution of + * 0.25 degree celsius and encoded in two's complement format. + */ + temp = (temp_buf[0] << 8) | temp_buf[1]; + temp >>= 6; + *mC = temp * 250; + + return 0; +} + +static ssize_t ds3231_hwmon_show_temp(struct device *dev, + struct device_attribute *attr, char *buf) +{ + int ret; + s32 temp; + + ret = ds3231_hwmon_read_temp(dev, &temp); + if (ret) + return ret; + + return sprintf(buf, "%d\n", temp); +} +static SENSOR_DEVICE_ATTR(temp1_input, 0444, ds3231_hwmon_show_temp, + NULL, 0); + +static struct attribute *ds3231_hwmon_attrs[] = { + &sensor_dev_attr_temp1_input.dev_attr.attr, + NULL, +}; +ATTRIBUTE_GROUPS(ds3231_hwmon); + +static void ds1307_hwmon_register(struct ds1307 *ds1307) +{ + struct device *dev; + + if (ds1307->type != ds_3231) + return; + + dev = devm_hwmon_device_register_with_groups(ds1307->dev, ds1307->name, + ds1307, + ds3231_hwmon_groups); + if (IS_ERR(dev)) { + dev_warn(ds1307->dev, "unable to register hwmon device %ld\n", + PTR_ERR(dev)); + } +} + +#else + +static void ds1307_hwmon_register(struct ds1307 *ds1307) +{ +} + +#endif /* CONFIG_RTC_DRV_DS1307_HWMON */ + +/*----------------------------------------------------------------------*/ + +/* + * Square-wave output support for DS3231 + * Datasheet: https://datasheets.maximintegrated.com/en/ds/DS3231.pdf + */ +#ifdef CONFIG_COMMON_CLK + +enum { + DS3231_CLK_SQW = 0, + DS3231_CLK_32KHZ, +}; + +#define clk_sqw_to_ds1307(clk) \ + container_of(clk, struct ds1307, clks[DS3231_CLK_SQW]) +#define clk_32khz_to_ds1307(clk) \ + container_of(clk, struct ds1307, clks[DS3231_CLK_32KHZ]) + +static int ds3231_clk_sqw_rates[] = { + 1, + 1024, + 4096, + 8192, +}; + +static int ds1337_write_control(struct ds1307 *ds1307, u8 mask, u8 value) +{ + struct mutex *lock = &ds1307->rtc->ops_lock; + int ret; + + mutex_lock(lock); + ret = regmap_update_bits(ds1307->regmap, DS1337_REG_CONTROL, + mask, value); + mutex_unlock(lock); + + return ret; +} + +static unsigned long ds3231_clk_sqw_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw); + int control, ret; + int rate_sel = 0; + + ret = regmap_read(ds1307->regmap, DS1337_REG_CONTROL, &control); + if (ret) + return ret; + if (control & DS1337_BIT_RS1) + rate_sel += 1; + if (control & DS1337_BIT_RS2) + rate_sel += 2; + + return ds3231_clk_sqw_rates[rate_sel]; +} + +static long ds3231_clk_sqw_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + int i; + + for (i = ARRAY_SIZE(ds3231_clk_sqw_rates) - 1; i >= 0; i--) { + if (ds3231_clk_sqw_rates[i] <= rate) + return ds3231_clk_sqw_rates[i]; + } + + return 0; +} + +static int ds3231_clk_sqw_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw); + int control = 0; + int rate_sel; + + for (rate_sel = 0; rate_sel < ARRAY_SIZE(ds3231_clk_sqw_rates); + rate_sel++) { + if (ds3231_clk_sqw_rates[rate_sel] == rate) + break; + } + + if (rate_sel == ARRAY_SIZE(ds3231_clk_sqw_rates)) + return -EINVAL; + + if (rate_sel & 1) + control |= DS1337_BIT_RS1; + if (rate_sel & 2) + control |= DS1337_BIT_RS2; + + return ds1337_write_control(ds1307, DS1337_BIT_RS1 | DS1337_BIT_RS2, + control); +} + +static int ds3231_clk_sqw_prepare(struct clk_hw *hw) +{ + struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw); + + return ds1337_write_control(ds1307, DS1337_BIT_INTCN, 0); +} + +static void ds3231_clk_sqw_unprepare(struct clk_hw *hw) +{ + struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw); + + ds1337_write_control(ds1307, DS1337_BIT_INTCN, DS1337_BIT_INTCN); +} + +static int ds3231_clk_sqw_is_prepared(struct clk_hw *hw) +{ + struct ds1307 *ds1307 = clk_sqw_to_ds1307(hw); + int control, ret; + + ret = regmap_read(ds1307->regmap, DS1337_REG_CONTROL, &control); + if (ret) + return ret; + + return !(control & DS1337_BIT_INTCN); +} + +static const struct clk_ops ds3231_clk_sqw_ops = { + .prepare = ds3231_clk_sqw_prepare, + .unprepare = ds3231_clk_sqw_unprepare, + .is_prepared = ds3231_clk_sqw_is_prepared, + .recalc_rate = ds3231_clk_sqw_recalc_rate, + .round_rate = ds3231_clk_sqw_round_rate, + .set_rate = ds3231_clk_sqw_set_rate, +}; + +static unsigned long ds3231_clk_32khz_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + return 32768; +} + +static int ds3231_clk_32khz_control(struct ds1307 *ds1307, bool enable) +{ + struct mutex *lock = &ds1307->rtc->ops_lock; + int ret; + + mutex_lock(lock); + ret = regmap_update_bits(ds1307->regmap, DS1337_REG_STATUS, + DS3231_BIT_EN32KHZ, + enable ? DS3231_BIT_EN32KHZ : 0); + mutex_unlock(lock); + + return ret; +} + +static int ds3231_clk_32khz_prepare(struct clk_hw *hw) +{ + struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw); + + return ds3231_clk_32khz_control(ds1307, true); +} + +static void ds3231_clk_32khz_unprepare(struct clk_hw *hw) +{ + struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw); + + ds3231_clk_32khz_control(ds1307, false); +} + +static int ds3231_clk_32khz_is_prepared(struct clk_hw *hw) +{ + struct ds1307 *ds1307 = clk_32khz_to_ds1307(hw); + int status, ret; + + ret = regmap_read(ds1307->regmap, DS1337_REG_STATUS, &status); + if (ret) + return ret; + + return !!(status & DS3231_BIT_EN32KHZ); +} + +static const struct clk_ops ds3231_clk_32khz_ops = { + .prepare = ds3231_clk_32khz_prepare, + .unprepare = ds3231_clk_32khz_unprepare, + .is_prepared = ds3231_clk_32khz_is_prepared, + .recalc_rate = ds3231_clk_32khz_recalc_rate, +}; + +static const char *ds3231_clks_names[] = { + [DS3231_CLK_SQW] = "ds3231_clk_sqw", + [DS3231_CLK_32KHZ] = "ds3231_clk_32khz", +}; + +static struct clk_init_data ds3231_clks_init[] = { + [DS3231_CLK_SQW] = { + .ops = &ds3231_clk_sqw_ops, + }, + [DS3231_CLK_32KHZ] = { + .ops = &ds3231_clk_32khz_ops, + }, +}; + +static int ds3231_clks_register(struct ds1307 *ds1307) +{ + struct device_node *node = ds1307->dev->of_node; + struct clk_onecell_data *onecell; + int i; + + onecell = devm_kzalloc(ds1307->dev, sizeof(*onecell), GFP_KERNEL); + if (!onecell) + return -ENOMEM; + + onecell->clk_num = ARRAY_SIZE(ds3231_clks_init); + onecell->clks = devm_kcalloc(ds1307->dev, onecell->clk_num, + sizeof(onecell->clks[0]), GFP_KERNEL); + if (!onecell->clks) + return -ENOMEM; + + /* optional override of the clockname */ + device_property_read_string_array(ds1307->dev, "clock-output-names", + ds3231_clks_names, + ARRAY_SIZE(ds3231_clks_names)); + + for (i = 0; i < ARRAY_SIZE(ds3231_clks_init); i++) { + struct clk_init_data init = ds3231_clks_init[i]; + + /* + * Interrupt signal due to alarm conditions and square-wave + * output share same pin, so don't initialize both. + */ + if (i == DS3231_CLK_SQW && test_bit(RTC_FEATURE_ALARM, ds1307->rtc->features)) + continue; + + init.name = ds3231_clks_names[i]; + ds1307->clks[i].init = &init; + + onecell->clks[i] = devm_clk_register(ds1307->dev, + &ds1307->clks[i]); + if (IS_ERR(onecell->clks[i])) + return PTR_ERR(onecell->clks[i]); + } + + if (node) + of_clk_add_provider(node, of_clk_src_onecell_get, onecell); + + return 0; +} + +static void ds1307_clks_register(struct ds1307 *ds1307) +{ + int ret; + + if (ds1307->type != ds_3231) + return; + + ret = ds3231_clks_register(ds1307); + if (ret) { + dev_warn(ds1307->dev, "unable to register clock device %d\n", + ret); + } +} + +#else + +static void ds1307_clks_register(struct ds1307 *ds1307) +{ +} + +#endif /* CONFIG_COMMON_CLK */ + +#ifdef CONFIG_WATCHDOG_CORE +static const struct watchdog_info ds1388_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, + .identity = "DS1388 watchdog", +}; + +static const struct watchdog_ops ds1388_wdt_ops = { + .owner = THIS_MODULE, + .start = ds1388_wdt_start, + .stop = ds1388_wdt_stop, + .ping = ds1388_wdt_ping, + .set_timeout = ds1388_wdt_set_timeout, + +}; + +static void ds1307_wdt_register(struct ds1307 *ds1307) +{ + struct watchdog_device *wdt; + int err; + int val; + + if (ds1307->type != ds_1388) + return; + + wdt = devm_kzalloc(ds1307->dev, sizeof(*wdt), GFP_KERNEL); + if (!wdt) + return; + + err = regmap_read(ds1307->regmap, DS1388_REG_FLAG, &val); + if (!err && val & DS1388_BIT_WF) + wdt->bootstatus = WDIOF_CARDRESET; + + wdt->info = &ds1388_wdt_info; + wdt->ops = &ds1388_wdt_ops; + wdt->timeout = 99; + wdt->max_timeout = 99; + wdt->min_timeout = 1; + + watchdog_init_timeout(wdt, 0, ds1307->dev); + watchdog_set_drvdata(wdt, ds1307); + devm_watchdog_register_device(ds1307->dev, wdt); +} +#else +static void ds1307_wdt_register(struct ds1307 *ds1307) +{ +} +#endif /* CONFIG_WATCHDOG_CORE */ + +static const struct regmap_config regmap_config = { + .reg_bits = 8, + .val_bits = 8, +}; + +static int ds1307_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct ds1307 *ds1307; + const void *match; + int err = -ENODEV; + int tmp; + const struct chip_desc *chip; + bool want_irq; + bool ds1307_can_wakeup_device = false; + unsigned char regs[8]; + struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev); + u8 trickle_charger_setup = 0; + + ds1307 = devm_kzalloc(&client->dev, sizeof(struct ds1307), GFP_KERNEL); + if (!ds1307) + return -ENOMEM; + + dev_set_drvdata(&client->dev, ds1307); + ds1307->dev = &client->dev; + ds1307->name = client->name; + + ds1307->regmap = devm_regmap_init_i2c(client, ®map_config); + if (IS_ERR(ds1307->regmap)) { + dev_err(ds1307->dev, "regmap allocation failed\n"); + return PTR_ERR(ds1307->regmap); + } + + i2c_set_clientdata(client, ds1307); + + match = device_get_match_data(&client->dev); + if (match) { + ds1307->type = (enum ds_type)match; + chip = &chips[ds1307->type]; + } else if (id) { + chip = &chips[id->driver_data]; + ds1307->type = id->driver_data; + } else { + return -ENODEV; + } + + want_irq = client->irq > 0 && chip->alarm; + + if (!pdata) + trickle_charger_setup = ds1307_trickle_init(ds1307, chip); + else if (pdata->trickle_charger_setup) + trickle_charger_setup = pdata->trickle_charger_setup; + + if (trickle_charger_setup && chip->trickle_charger_reg) { + dev_dbg(ds1307->dev, + "writing trickle charger info 0x%x to 0x%x\n", + trickle_charger_setup, chip->trickle_charger_reg); + regmap_write(ds1307->regmap, chip->trickle_charger_reg, + trickle_charger_setup); + } + +/* + * For devices with no IRQ directly connected to the SoC, the RTC chip + * can be forced as a wakeup source by stating that explicitly in + * the device's .dts file using the "wakeup-source" boolean property. + * If the "wakeup-source" property is set, don't request an IRQ. + * This will guarantee the 'wakealarm' sysfs entry is available on the device, + * if supported by the RTC. + */ + if (chip->alarm && device_property_read_bool(&client->dev, "wakeup-source")) + ds1307_can_wakeup_device = true; + + switch (ds1307->type) { + case ds_1337: + case ds_1339: + case ds_1341: + case ds_3231: + /* get registers that the "rtc" read below won't read... */ + err = regmap_bulk_read(ds1307->regmap, DS1337_REG_CONTROL, + regs, 2); + if (err) { + dev_dbg(ds1307->dev, "read error %d\n", err); + goto exit; + } + + /* oscillator off? turn it on, so clock can tick. */ + if (regs[0] & DS1337_BIT_nEOSC) + regs[0] &= ~DS1337_BIT_nEOSC; + + /* + * Using IRQ or defined as wakeup-source? + * Disable the square wave and both alarms. + * For some variants, be sure alarms can trigger when we're + * running on Vbackup (BBSQI/BBSQW) + */ + if (want_irq || ds1307_can_wakeup_device) { + regs[0] |= DS1337_BIT_INTCN | chip->bbsqi_bit; + regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE); + } + + regmap_write(ds1307->regmap, DS1337_REG_CONTROL, + regs[0]); + + /* oscillator fault? clear flag, and warn */ + if (regs[1] & DS1337_BIT_OSF) { + regmap_write(ds1307->regmap, DS1337_REG_STATUS, + regs[1] & ~DS1337_BIT_OSF); + dev_warn(ds1307->dev, "SET TIME!\n"); + } + break; + + case rx_8025: + err = regmap_bulk_read(ds1307->regmap, + RX8025_REG_CTRL1 << 4 | 0x08, regs, 2); + if (err) { + dev_dbg(ds1307->dev, "read error %d\n", err); + goto exit; + } + + /* oscillator off? turn it on, so clock can tick. */ + if (!(regs[1] & RX8025_BIT_XST)) { + regs[1] |= RX8025_BIT_XST; + regmap_write(ds1307->regmap, + RX8025_REG_CTRL2 << 4 | 0x08, + regs[1]); + dev_warn(ds1307->dev, + "oscillator stop detected - SET TIME!\n"); + } + + if (regs[1] & RX8025_BIT_PON) { + regs[1] &= ~RX8025_BIT_PON; + regmap_write(ds1307->regmap, + RX8025_REG_CTRL2 << 4 | 0x08, + regs[1]); + dev_warn(ds1307->dev, "power-on detected\n"); + } + + if (regs[1] & RX8025_BIT_VDET) { + regs[1] &= ~RX8025_BIT_VDET; + regmap_write(ds1307->regmap, + RX8025_REG_CTRL2 << 4 | 0x08, + regs[1]); + dev_warn(ds1307->dev, "voltage drop detected\n"); + } + + /* make sure we are running in 24hour mode */ + if (!(regs[0] & RX8025_BIT_2412)) { + u8 hour; + + /* switch to 24 hour mode */ + regmap_write(ds1307->regmap, + RX8025_REG_CTRL1 << 4 | 0x08, + regs[0] | RX8025_BIT_2412); + + err = regmap_bulk_read(ds1307->regmap, + RX8025_REG_CTRL1 << 4 | 0x08, + regs, 2); + if (err) { + dev_dbg(ds1307->dev, "read error %d\n", err); + goto exit; + } + + /* correct hour */ + hour = bcd2bin(regs[DS1307_REG_HOUR]); + if (hour == 12) + hour = 0; + if (regs[DS1307_REG_HOUR] & DS1307_BIT_PM) + hour += 12; + + regmap_write(ds1307->regmap, + DS1307_REG_HOUR << 4 | 0x08, hour); + } + break; + case ds_1388: + err = regmap_read(ds1307->regmap, DS1388_REG_CONTROL, &tmp); + if (err) { + dev_dbg(ds1307->dev, "read error %d\n", err); + goto exit; + } + + /* oscillator off? turn it on, so clock can tick. */ + if (tmp & DS1388_BIT_nEOSC) { + tmp &= ~DS1388_BIT_nEOSC; + regmap_write(ds1307->regmap, DS1388_REG_CONTROL, tmp); + } + break; + default: + break; + } + + /* read RTC registers */ + err = regmap_bulk_read(ds1307->regmap, chip->offset, regs, + sizeof(regs)); + if (err) { + dev_dbg(ds1307->dev, "read error %d\n", err); + goto exit; + } + + if (ds1307->type == mcp794xx && + !(regs[DS1307_REG_WDAY] & MCP794XX_BIT_VBATEN)) { + regmap_write(ds1307->regmap, DS1307_REG_WDAY, + regs[DS1307_REG_WDAY] | + MCP794XX_BIT_VBATEN); + } + + tmp = regs[DS1307_REG_HOUR]; + switch (ds1307->type) { + case ds_1340: + case m41t0: + case m41t00: + case m41t11: + /* + * NOTE: ignores century bits; fix before deploying + * systems that will run through year 2100. + */ + break; + case rx_8025: + break; + default: + if (!(tmp & DS1307_BIT_12HR)) + break; + + /* + * Be sure we're in 24 hour mode. Multi-master systems + * take note... + */ + tmp = bcd2bin(tmp & 0x1f); + if (tmp == 12) + tmp = 0; + if (regs[DS1307_REG_HOUR] & DS1307_BIT_PM) + tmp += 12; + regmap_write(ds1307->regmap, chip->offset + DS1307_REG_HOUR, + bin2bcd(tmp)); + } + + ds1307->rtc = devm_rtc_allocate_device(ds1307->dev); + if (IS_ERR(ds1307->rtc)) + return PTR_ERR(ds1307->rtc); + + if (want_irq || ds1307_can_wakeup_device) + device_set_wakeup_capable(ds1307->dev, true); + else + clear_bit(RTC_FEATURE_ALARM, ds1307->rtc->features); + + if (ds1307_can_wakeup_device && !want_irq) { + dev_info(ds1307->dev, + "'wakeup-source' is set, request for an IRQ is disabled!\n"); + /* We cannot support UIE mode if we do not have an IRQ line */ + clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, ds1307->rtc->features); + } + + if (want_irq) { + err = devm_request_threaded_irq(ds1307->dev, client->irq, NULL, + chip->irq_handler ?: ds1307_irq, + IRQF_SHARED | IRQF_ONESHOT, + ds1307->name, ds1307); + if (err) { + client->irq = 0; + device_set_wakeup_capable(ds1307->dev, false); + clear_bit(RTC_FEATURE_ALARM, ds1307->rtc->features); + dev_err(ds1307->dev, "unable to request IRQ!\n"); + } else { + dev_dbg(ds1307->dev, "got IRQ %d\n", client->irq); + } + } + + ds1307->rtc->ops = chip->rtc_ops ?: &ds13xx_rtc_ops; + err = ds1307_add_frequency_test(ds1307); + if (err) + return err; + + err = devm_rtc_register_device(ds1307->rtc); + if (err) + return err; + + if (chip->nvram_size) { + struct nvmem_config nvmem_cfg = { + .name = "ds1307_nvram", + .word_size = 1, + .stride = 1, + .size = chip->nvram_size, + .reg_read = ds1307_nvram_read, + .reg_write = ds1307_nvram_write, + .priv = ds1307, + }; + + devm_rtc_nvmem_register(ds1307->rtc, &nvmem_cfg); + } + + ds1307_hwmon_register(ds1307); + ds1307_clks_register(ds1307); + ds1307_wdt_register(ds1307); + + return 0; + +exit: + return err; +} + +static struct i2c_driver ds1307_driver = { + .driver = { + .name = "rtc-ds1307", + .of_match_table = ds1307_of_match, + }, + .probe = ds1307_probe, + .id_table = ds1307_id, +}; + +module_i2c_driver(ds1307_driver); + +MODULE_DESCRIPTION("RTC driver for DS1307 and similar chips"); +MODULE_LICENSE("GPL"); |