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linux/drivers/rtc/rtc-ds1307.c
Csókás, Bence 68f78c720d rtc: ds1307: Clamp year to valid BCD (0-99) in set_time() 
`tm_year` may go up to 299 if the device supports the
century bit. Therefore, subtracting may not give us
a valid 2-digit number, but modulo does.

Co-developed-by: Szentendrei, Tamás <szentendrei.tamas@prolan.hu>
Signed-off-by: Szentendrei, Tamás <szentendrei.tamas@prolan.hu>
Signed-off-by: Csókás, Bence <csokas.bence@prolan.hu>
Link: https://lore.kernel.org/r/20240611072411.671600-2-csokas.bence@prolan.hu
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2024-07-07 00:39:27 +02:00

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// 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/kstrtox.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_OSCRUN BIT(5)
# 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, &regflag);
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;
} else if (ds1307->type == mcp794xx &&
!(regs[DS1307_REG_WDAY] & MCP794XX_BIT_OSCRUN)) {
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",
&regs[0], &regs[4], &regs[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)",
&regs[0], &regs[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, &reg);
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, &reg);
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 sysfs_emit(buf, (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 = i2c_client_get_device_id(client);
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, &regmap_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 = (uintptr_t)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");
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