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remarkable-linux/drivers/rtc/rtc-ab-b5ze-s3.c
Javier Martinez Canillas 1c4fc2955a rtc: Export OF module alias information in missing drivers 
The I2C core always reports the MODALIAS uevent as "i2c:<client name"
regardless if the driver was matched using the I2C id_table or the
of_match_table. So technically there's no need for a driver to export
the OF table since currently it's not used.

In fact, the I2C device ID table is mandatory for I2C drivers since
a i2c_device_id is passed to the driver's probe function even if the
I2C core used the OF table to match the driver.

And since the I2C core uses different tables, OF-only drivers needs to
have duplicated data that has to be kept in sync and also the dev node
compatible manufacturer prefix is stripped when reporting the MODALIAS.

To avoid the above, the I2C core behavior may be changed in the future
to not require an I2C device table for OF-only drivers and report the
OF module alias. So, it's better to also export the OF table to prevent
breaking module autoloading if that happens.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2015-09-05 13:19:08 +02:00

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/*
* rtc-ab-b5ze-s3 - Driver for Abracon AB-RTCMC-32.768Khz-B5ZE-S3
* I2C RTC / Alarm chip
*
* Copyright (C) 2014, Arnaud EBALARD <arno@natisbad.org>
*
* Detailed datasheet of the chip is available here:
*
* http://www.abracon.com/realtimeclock/AB-RTCMC-32.768kHz-B5ZE-S3-Application-Manual.pdf
*
* This work is based on ISL12057 driver (drivers/rtc/rtc-isl12057.c).
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/rtc.h>
#include <linux/i2c.h>
#include <linux/bcd.h>
#include <linux/of.h>
#include <linux/regmap.h>
#include <linux/interrupt.h>
#define DRV_NAME "rtc-ab-b5ze-s3"
/* Control section */
#define ABB5ZES3_REG_CTRL1 0x00 /* Control 1 register */
#define ABB5ZES3_REG_CTRL1_CIE BIT(0) /* Pulse interrupt enable */
#define ABB5ZES3_REG_CTRL1_AIE BIT(1) /* Alarm interrupt enable */
#define ABB5ZES3_REG_CTRL1_SIE BIT(2) /* Second interrupt enable */
#define ABB5ZES3_REG_CTRL1_PM BIT(3) /* 24h/12h mode */
#define ABB5ZES3_REG_CTRL1_SR BIT(4) /* Software reset */
#define ABB5ZES3_REG_CTRL1_STOP BIT(5) /* RTC circuit enable */
#define ABB5ZES3_REG_CTRL1_CAP BIT(7)
#define ABB5ZES3_REG_CTRL2 0x01 /* Control 2 register */
#define ABB5ZES3_REG_CTRL2_CTBIE BIT(0) /* Countdown timer B int. enable */
#define ABB5ZES3_REG_CTRL2_CTAIE BIT(1) /* Countdown timer A int. enable */
#define ABB5ZES3_REG_CTRL2_WTAIE BIT(2) /* Watchdog timer A int. enable */
#define ABB5ZES3_REG_CTRL2_AF BIT(3) /* Alarm interrupt status */
#define ABB5ZES3_REG_CTRL2_SF BIT(4) /* Second interrupt status */
#define ABB5ZES3_REG_CTRL2_CTBF BIT(5) /* Countdown timer B int. status */
#define ABB5ZES3_REG_CTRL2_CTAF BIT(6) /* Countdown timer A int. status */
#define ABB5ZES3_REG_CTRL2_WTAF BIT(7) /* Watchdog timer A int. status */
#define ABB5ZES3_REG_CTRL3 0x02 /* Control 3 register */
#define ABB5ZES3_REG_CTRL3_PM2 BIT(7) /* Power Management bit 2 */
#define ABB5ZES3_REG_CTRL3_PM1 BIT(6) /* Power Management bit 1 */
#define ABB5ZES3_REG_CTRL3_PM0 BIT(5) /* Power Management bit 0 */
#define ABB5ZES3_REG_CTRL3_BSF BIT(3) /* Battery switchover int. status */
#define ABB5ZES3_REG_CTRL3_BLF BIT(2) /* Battery low int. status */
#define ABB5ZES3_REG_CTRL3_BSIE BIT(1) /* Battery switchover int. enable */
#define ABB5ZES3_REG_CTRL3_BLIE BIT(0) /* Battery low int. enable */
#define ABB5ZES3_CTRL_SEC_LEN 3
/* RTC section */
#define ABB5ZES3_REG_RTC_SC 0x03 /* RTC Seconds register */
#define ABB5ZES3_REG_RTC_SC_OSC BIT(7) /* Clock integrity status */
#define ABB5ZES3_REG_RTC_MN 0x04 /* RTC Minutes register */
#define ABB5ZES3_REG_RTC_HR 0x05 /* RTC Hours register */
#define ABB5ZES3_REG_RTC_HR_PM BIT(5) /* RTC Hours PM bit */
#define ABB5ZES3_REG_RTC_DT 0x06 /* RTC Date register */
#define ABB5ZES3_REG_RTC_DW 0x07 /* RTC Day of the week register */
#define ABB5ZES3_REG_RTC_MO 0x08 /* RTC Month register */
#define ABB5ZES3_REG_RTC_YR 0x09 /* RTC Year register */
#define ABB5ZES3_RTC_SEC_LEN 7
/* Alarm section (enable bits are all active low) */
#define ABB5ZES3_REG_ALRM_MN 0x0A /* Alarm - minute register */
#define ABB5ZES3_REG_ALRM_MN_AE BIT(7) /* Minute enable */
#define ABB5ZES3_REG_ALRM_HR 0x0B /* Alarm - hours register */
#define ABB5ZES3_REG_ALRM_HR_AE BIT(7) /* Hour enable */
#define ABB5ZES3_REG_ALRM_DT 0x0C /* Alarm - date register */
#define ABB5ZES3_REG_ALRM_DT_AE BIT(7) /* Date (day of the month) enable */
#define ABB5ZES3_REG_ALRM_DW 0x0D /* Alarm - day of the week reg. */
#define ABB5ZES3_REG_ALRM_DW_AE BIT(7) /* Day of the week enable */
#define ABB5ZES3_ALRM_SEC_LEN 4
/* Frequency offset section */
#define ABB5ZES3_REG_FREQ_OF 0x0E /* Frequency offset register */
#define ABB5ZES3_REG_FREQ_OF_MODE 0x0E /* Offset mode: 2 hours / minute */
/* CLOCKOUT section */
#define ABB5ZES3_REG_TIM_CLK 0x0F /* Timer & Clockout register */
#define ABB5ZES3_REG_TIM_CLK_TAM BIT(7) /* Permanent/pulsed timer A/int. 2 */
#define ABB5ZES3_REG_TIM_CLK_TBM BIT(6) /* Permanent/pulsed timer B */
#define ABB5ZES3_REG_TIM_CLK_COF2 BIT(5) /* Clkout Freq bit 2 */
#define ABB5ZES3_REG_TIM_CLK_COF1 BIT(4) /* Clkout Freq bit 1 */
#define ABB5ZES3_REG_TIM_CLK_COF0 BIT(3) /* Clkout Freq bit 0 */
#define ABB5ZES3_REG_TIM_CLK_TAC1 BIT(2) /* Timer A: - 01 : countdown */
#define ABB5ZES3_REG_TIM_CLK_TAC0 BIT(1) /* - 10 : timer */
#define ABB5ZES3_REG_TIM_CLK_TBC BIT(0) /* Timer B enable */
/* Timer A Section */
#define ABB5ZES3_REG_TIMA_CLK 0x10 /* Timer A clock register */
#define ABB5ZES3_REG_TIMA_CLK_TAQ2 BIT(2) /* Freq bit 2 */
#define ABB5ZES3_REG_TIMA_CLK_TAQ1 BIT(1) /* Freq bit 1 */
#define ABB5ZES3_REG_TIMA_CLK_TAQ0 BIT(0) /* Freq bit 0 */
#define ABB5ZES3_REG_TIMA 0x11 /* Timer A register */
#define ABB5ZES3_TIMA_SEC_LEN 2
/* Timer B Section */
#define ABB5ZES3_REG_TIMB_CLK 0x12 /* Timer B clock register */
#define ABB5ZES3_REG_TIMB_CLK_TBW2 BIT(6)
#define ABB5ZES3_REG_TIMB_CLK_TBW1 BIT(5)
#define ABB5ZES3_REG_TIMB_CLK_TBW0 BIT(4)
#define ABB5ZES3_REG_TIMB_CLK_TAQ2 BIT(2)
#define ABB5ZES3_REG_TIMB_CLK_TAQ1 BIT(1)
#define ABB5ZES3_REG_TIMB_CLK_TAQ0 BIT(0)
#define ABB5ZES3_REG_TIMB 0x13 /* Timer B register */
#define ABB5ZES3_TIMB_SEC_LEN 2
#define ABB5ZES3_MEM_MAP_LEN 0x14
struct abb5zes3_rtc_data {
struct rtc_device *rtc;
struct regmap *regmap;
struct mutex lock;
int irq;
bool battery_low;
bool timer_alarm; /* current alarm is via timer A */
};
/*
* Try and match register bits w/ fixed null values to see whether we
* are dealing with an ABB5ZES3. Note: this function is called early
* during init and hence does need mutex protection.
*/
static int abb5zes3_i2c_validate_chip(struct regmap *regmap)
{
u8 regs[ABB5ZES3_MEM_MAP_LEN];
static const u8 mask[ABB5ZES3_MEM_MAP_LEN] = { 0x00, 0x00, 0x10, 0x00,
0x80, 0xc0, 0xc0, 0xf8,
0xe0, 0x00, 0x00, 0x40,
0x40, 0x78, 0x00, 0x00,
0xf8, 0x00, 0x88, 0x00 };
int ret, i;
ret = regmap_bulk_read(regmap, 0, regs, ABB5ZES3_MEM_MAP_LEN);
if (ret)
return ret;
for (i = 0; i < ABB5ZES3_MEM_MAP_LEN; ++i) {
if (regs[i] & mask[i]) /* check if bits are cleared */
return -ENODEV;
}
return 0;
}
/* Clear alarm status bit. */
static int _abb5zes3_rtc_clear_alarm(struct device *dev)
{
struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
int ret;
ret = regmap_update_bits(data->regmap, ABB5ZES3_REG_CTRL2,
ABB5ZES3_REG_CTRL2_AF, 0);
if (ret)
dev_err(dev, "%s: clearing alarm failed (%d)\n", __func__, ret);
return ret;
}
/* Enable or disable alarm (i.e. alarm interrupt generation) */
static int _abb5zes3_rtc_update_alarm(struct device *dev, bool enable)
{
struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
int ret;
ret = regmap_update_bits(data->regmap, ABB5ZES3_REG_CTRL1,
ABB5ZES3_REG_CTRL1_AIE,
enable ? ABB5ZES3_REG_CTRL1_AIE : 0);
if (ret)
dev_err(dev, "%s: writing alarm INT failed (%d)\n",
__func__, ret);
return ret;
}
/* Enable or disable timer (watchdog timer A interrupt generation) */
static int _abb5zes3_rtc_update_timer(struct device *dev, bool enable)
{
struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
int ret;
ret = regmap_update_bits(data->regmap, ABB5ZES3_REG_CTRL2,
ABB5ZES3_REG_CTRL2_WTAIE,
enable ? ABB5ZES3_REG_CTRL2_WTAIE : 0);
if (ret)
dev_err(dev, "%s: writing timer INT failed (%d)\n",
__func__, ret);
return ret;
}
/*
* Note: we only read, so regmap inner lock protection is sufficient, i.e.
* we do not need driver's main lock protection.
*/
static int _abb5zes3_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
u8 regs[ABB5ZES3_REG_RTC_SC + ABB5ZES3_RTC_SEC_LEN];
int ret;
/*
* As we need to read CTRL1 register anyway to access 24/12h
* mode bit, we do a single bulk read of both control and RTC
* sections (they are consecutive). This also ease indexing
* of register values after bulk read.
*/
ret = regmap_bulk_read(data->regmap, ABB5ZES3_REG_CTRL1, regs,
sizeof(regs));
if (ret) {
dev_err(dev, "%s: reading RTC time failed (%d)\n",
__func__, ret);
goto err;
}
/* If clock integrity is not guaranteed, do not return a time value */
if (regs[ABB5ZES3_REG_RTC_SC] & ABB5ZES3_REG_RTC_SC_OSC) {
ret = -ENODATA;
goto err;
}
tm->tm_sec = bcd2bin(regs[ABB5ZES3_REG_RTC_SC] & 0x7F);
tm->tm_min = bcd2bin(regs[ABB5ZES3_REG_RTC_MN]);
if (regs[ABB5ZES3_REG_CTRL1] & ABB5ZES3_REG_CTRL1_PM) { /* 12hr mode */
tm->tm_hour = bcd2bin(regs[ABB5ZES3_REG_RTC_HR] & 0x1f);
if (regs[ABB5ZES3_REG_RTC_HR] & ABB5ZES3_REG_RTC_HR_PM) /* PM */
tm->tm_hour += 12;
} else { /* 24hr mode */
tm->tm_hour = bcd2bin(regs[ABB5ZES3_REG_RTC_HR]);
}
tm->tm_mday = bcd2bin(regs[ABB5ZES3_REG_RTC_DT]);
tm->tm_wday = bcd2bin(regs[ABB5ZES3_REG_RTC_DW]);
tm->tm_mon = bcd2bin(regs[ABB5ZES3_REG_RTC_MO]) - 1; /* starts at 1 */
tm->tm_year = bcd2bin(regs[ABB5ZES3_REG_RTC_YR]) + 100;
ret = rtc_valid_tm(tm);
err:
return ret;
}
static int abb5zes3_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
u8 regs[ABB5ZES3_REG_RTC_SC + ABB5ZES3_RTC_SEC_LEN];
int ret;
/*
* Year register is 8-bit wide and bcd-coded, i.e records values
* between 0 and 99. tm_year is an offset from 1900 and we are
* interested in the 2000-2099 range, so any value less than 100
* is invalid.
*/
if (tm->tm_year < 100)
return -EINVAL;
regs[ABB5ZES3_REG_RTC_SC] = bin2bcd(tm->tm_sec); /* MSB=0 clears OSC */
regs[ABB5ZES3_REG_RTC_MN] = bin2bcd(tm->tm_min);
regs[ABB5ZES3_REG_RTC_HR] = bin2bcd(tm->tm_hour); /* 24-hour format */
regs[ABB5ZES3_REG_RTC_DT] = bin2bcd(tm->tm_mday);
regs[ABB5ZES3_REG_RTC_DW] = bin2bcd(tm->tm_wday);
regs[ABB5ZES3_REG_RTC_MO] = bin2bcd(tm->tm_mon + 1);
regs[ABB5ZES3_REG_RTC_YR] = bin2bcd(tm->tm_year - 100);
mutex_lock(&data->lock);
ret = regmap_bulk_write(data->regmap, ABB5ZES3_REG_RTC_SC,
regs + ABB5ZES3_REG_RTC_SC,
ABB5ZES3_RTC_SEC_LEN);
mutex_unlock(&data->lock);
return ret;
}
/*
* Set provided TAQ and Timer A registers (TIMA_CLK and TIMA) based on
* given number of seconds.
*/
static inline void sec_to_timer_a(u8 secs, u8 *taq, u8 *timer_a)
{
*taq = ABB5ZES3_REG_TIMA_CLK_TAQ1; /* 1Hz */
*timer_a = secs;
}
/*
* Return current number of seconds in Timer A. As we only use
* timer A with a 1Hz freq, this is what we expect to have.
*/
static inline int sec_from_timer_a(u8 *secs, u8 taq, u8 timer_a)
{
if (taq != ABB5ZES3_REG_TIMA_CLK_TAQ1) /* 1Hz */
return -EINVAL;
*secs = timer_a;
return 0;
}
/*
* Read alarm currently configured via a watchdog timer using timer A. This
* is done by reading current RTC time and adding remaining timer time.
*/
static int _abb5zes3_rtc_read_timer(struct device *dev,
struct rtc_wkalrm *alarm)
{
struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
struct rtc_time rtc_tm, *alarm_tm = &alarm->time;
u8 regs[ABB5ZES3_TIMA_SEC_LEN + 1];
unsigned long rtc_secs;
unsigned int reg;
u8 timer_secs;
int ret;
/*
* Instead of doing two separate calls, because they are consecutive,
* we grab both clockout register and Timer A section. The latter is
* used to decide if timer A is enabled (as a watchdog timer).
*/
ret = regmap_bulk_read(data->regmap, ABB5ZES3_REG_TIM_CLK, regs,
ABB5ZES3_TIMA_SEC_LEN + 1);
if (ret) {
dev_err(dev, "%s: reading Timer A section failed (%d)\n",
__func__, ret);
goto err;
}
/* get current time ... */
ret = _abb5zes3_rtc_read_time(dev, &rtc_tm);
if (ret)
goto err;
/* ... convert to seconds ... */
ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
if (ret)
goto err;
/* ... add remaining timer A time ... */
ret = sec_from_timer_a(&timer_secs, regs[1], regs[2]);
if (ret)
goto err;
/* ... and convert back. */
rtc_time_to_tm(rtc_secs + timer_secs, alarm_tm);
ret = regmap_read(data->regmap, ABB5ZES3_REG_CTRL2, &reg);
if (ret) {
dev_err(dev, "%s: reading ctrl reg failed (%d)\n",
__func__, ret);
goto err;
}
alarm->enabled = !!(reg & ABB5ZES3_REG_CTRL2_WTAIE);
err:
return ret;
}
/* Read alarm currently configured via a RTC alarm registers. */
static int _abb5zes3_rtc_read_alarm(struct device *dev,
struct rtc_wkalrm *alarm)
{
struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
struct rtc_time rtc_tm, *alarm_tm = &alarm->time;
unsigned long rtc_secs, alarm_secs;
u8 regs[ABB5ZES3_ALRM_SEC_LEN];
unsigned int reg;
int ret;
ret = regmap_bulk_read(data->regmap, ABB5ZES3_REG_ALRM_MN, regs,
ABB5ZES3_ALRM_SEC_LEN);
if (ret) {
dev_err(dev, "%s: reading alarm section failed (%d)\n",
__func__, ret);
goto err;
}
alarm_tm->tm_sec = 0;
alarm_tm->tm_min = bcd2bin(regs[0] & 0x7f);
alarm_tm->tm_hour = bcd2bin(regs[1] & 0x3f);
alarm_tm->tm_mday = bcd2bin(regs[2] & 0x3f);
alarm_tm->tm_wday = -1;
/*
* The alarm section does not store year/month. We use the ones in rtc
* section as a basis and increment month and then year if needed to get
* alarm after current time.
*/
ret = _abb5zes3_rtc_read_time(dev, &rtc_tm);
if (ret)
goto err;
alarm_tm->tm_year = rtc_tm.tm_year;
alarm_tm->tm_mon = rtc_tm.tm_mon;
ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
if (ret)
goto err;
ret = rtc_tm_to_time(alarm_tm, &alarm_secs);
if (ret)
goto err;
if (alarm_secs < rtc_secs) {
if (alarm_tm->tm_mon == 11) {
alarm_tm->tm_mon = 0;
alarm_tm->tm_year += 1;
} else {
alarm_tm->tm_mon += 1;
}
}
ret = regmap_read(data->regmap, ABB5ZES3_REG_CTRL1, &reg);
if (ret) {
dev_err(dev, "%s: reading ctrl reg failed (%d)\n",
__func__, ret);
goto err;
}
alarm->enabled = !!(reg & ABB5ZES3_REG_CTRL1_AIE);
err:
return ret;
}
/*
* As the Alarm mechanism supported by the chip is only accurate to the
* minute, we use the watchdog timer mechanism provided by timer A
* (up to 256 seconds w/ a second accuracy) for low alarm values (below
* 4 minutes). Otherwise, we use the common alarm mechanism provided
* by the chip. In order for that to work, we keep track of currently
* configured timer type via 'timer_alarm' flag in our private data
* structure.
*/
static int abb5zes3_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
int ret;
mutex_lock(&data->lock);
if (data->timer_alarm)
ret = _abb5zes3_rtc_read_timer(dev, alarm);
else
ret = _abb5zes3_rtc_read_alarm(dev, alarm);
mutex_unlock(&data->lock);
return ret;
}
/*
* Set alarm using chip alarm mechanism. It is only accurate to the
* minute (not the second). The function expects alarm interrupt to
* be disabled.
*/
static int _abb5zes3_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
struct rtc_time *alarm_tm = &alarm->time;
unsigned long rtc_secs, alarm_secs;
u8 regs[ABB5ZES3_ALRM_SEC_LEN];
struct rtc_time rtc_tm;
int ret, enable = 1;
ret = _abb5zes3_rtc_read_time(dev, &rtc_tm);
if (ret)
goto err;
ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
if (ret)
goto err;
ret = rtc_tm_to_time(alarm_tm, &alarm_secs);
if (ret)
goto err;
/* If alarm time is before current time, disable the alarm */
if (!alarm->enabled || alarm_secs <= rtc_secs) {
enable = 0;
} else {
/*
* Chip only support alarms up to one month in the future. Let's
* return an error if we get something after that limit.
* Comparison is done by incrementing rtc_tm month field by one
* and checking alarm value is still below.
*/
if (rtc_tm.tm_mon == 11) { /* handle year wrapping */
rtc_tm.tm_mon = 0;
rtc_tm.tm_year += 1;
} else {
rtc_tm.tm_mon += 1;
}
ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
if (ret)
goto err;
if (alarm_secs > rtc_secs) {
dev_err(dev, "%s: alarm maximum is one month in the "
"future (%d)\n", __func__, ret);
ret = -EINVAL;
goto err;
}
}
/*
* Program all alarm registers but DW one. For each register, setting
* MSB to 0 enables associated alarm.
*/
regs[0] = bin2bcd(alarm_tm->tm_min) & 0x7f;
regs[1] = bin2bcd(alarm_tm->tm_hour) & 0x3f;
regs[2] = bin2bcd(alarm_tm->tm_mday) & 0x3f;
regs[3] = ABB5ZES3_REG_ALRM_DW_AE; /* do not match day of the week */
ret = regmap_bulk_write(data->regmap, ABB5ZES3_REG_ALRM_MN, regs,
ABB5ZES3_ALRM_SEC_LEN);
if (ret < 0) {
dev_err(dev, "%s: writing ALARM section failed (%d)\n",
__func__, ret);
goto err;
}
/* Record currently configured alarm is not a timer */
data->timer_alarm = 0;
/* Enable or disable alarm interrupt generation */
ret = _abb5zes3_rtc_update_alarm(dev, enable);
err:
return ret;
}
/*
* Set alarm using timer watchdog (via timer A) mechanism. The function expects
* timer A interrupt to be disabled.
*/
static int _abb5zes3_rtc_set_timer(struct device *dev, struct rtc_wkalrm *alarm,
u8 secs)
{
struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
u8 regs[ABB5ZES3_TIMA_SEC_LEN];
u8 mask = ABB5ZES3_REG_TIM_CLK_TAC0 | ABB5ZES3_REG_TIM_CLK_TAC1;
int ret = 0;
/* Program given number of seconds to Timer A registers */
sec_to_timer_a(secs, &regs[0], &regs[1]);
ret = regmap_bulk_write(data->regmap, ABB5ZES3_REG_TIMA_CLK, regs,
ABB5ZES3_TIMA_SEC_LEN);
if (ret < 0) {
dev_err(dev, "%s: writing timer section failed\n", __func__);
goto err;
}
/* Configure Timer A as a watchdog timer */
ret = regmap_update_bits(data->regmap, ABB5ZES3_REG_TIM_CLK,
mask, ABB5ZES3_REG_TIM_CLK_TAC1);
if (ret)
dev_err(dev, "%s: failed to update timer\n", __func__);
/* Record currently configured alarm is a timer */
data->timer_alarm = 1;
/* Enable or disable timer interrupt generation */
ret = _abb5zes3_rtc_update_timer(dev, alarm->enabled);
err:
return ret;
}
/*
* The chip has an alarm which is only accurate to the minute. In order to
* handle alarms below that limit, we use the watchdog timer function of
* timer A. More precisely, the timer method is used for alarms below 240
* seconds.
*/
static int abb5zes3_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
struct rtc_time *alarm_tm = &alarm->time;
unsigned long rtc_secs, alarm_secs;
struct rtc_time rtc_tm;
int ret;
mutex_lock(&data->lock);
ret = _abb5zes3_rtc_read_time(dev, &rtc_tm);
if (ret)
goto err;
ret = rtc_tm_to_time(&rtc_tm, &rtc_secs);
if (ret)
goto err;
ret = rtc_tm_to_time(alarm_tm, &alarm_secs);
if (ret)
goto err;
/* Let's first disable both the alarm and the timer interrupts */
ret = _abb5zes3_rtc_update_alarm(dev, false);
if (ret < 0) {
dev_err(dev, "%s: unable to disable alarm (%d)\n", __func__,
ret);
goto err;
}
ret = _abb5zes3_rtc_update_timer(dev, false);
if (ret < 0) {
dev_err(dev, "%s: unable to disable timer (%d)\n", __func__,
ret);
goto err;
}
data->timer_alarm = 0;
/*
* Let's now configure the alarm; if we are expected to ring in
* more than 240s, then we setup an alarm. Otherwise, a timer.
*/
if ((alarm_secs > rtc_secs) && ((alarm_secs - rtc_secs) <= 240))
ret = _abb5zes3_rtc_set_timer(dev, alarm,
alarm_secs - rtc_secs);
else
ret = _abb5zes3_rtc_set_alarm(dev, alarm);
err:
mutex_unlock(&data->lock);
if (ret)
dev_err(dev, "%s: unable to configure alarm (%d)\n", __func__,
ret);
return ret;
}
/* Enable or disable battery low irq generation */
static inline int _abb5zes3_rtc_battery_low_irq_enable(struct regmap *regmap,
bool enable)
{
return regmap_update_bits(regmap, ABB5ZES3_REG_CTRL3,
ABB5ZES3_REG_CTRL3_BLIE,
enable ? ABB5ZES3_REG_CTRL3_BLIE : 0);
}
/*
* Check current RTC status and enable/disable what needs to be. Return 0 if
* everything went ok and a negative value upon error. Note: this function
* is called early during init and hence does need mutex protection.
*/
static int abb5zes3_rtc_check_setup(struct device *dev)
{
struct abb5zes3_rtc_data *data = dev_get_drvdata(dev);
struct regmap *regmap = data->regmap;
unsigned int reg;
int ret;
u8 mask;
/*
* By default, the devices generates a 32.768KHz signal on IRQ#1 pin. It
* is disabled here to prevent polluting the interrupt line and
* uselessly triggering the IRQ handler we install for alarm and battery
* low events. Note: this is done before clearing int. status below
* in this function.
* We also disable all timers and set timer interrupt to permanent (not
* pulsed).
*/
mask = (ABB5ZES3_REG_TIM_CLK_TBC | ABB5ZES3_REG_TIM_CLK_TAC0 |
ABB5ZES3_REG_TIM_CLK_TAC1 | ABB5ZES3_REG_TIM_CLK_COF0 |
ABB5ZES3_REG_TIM_CLK_COF1 | ABB5ZES3_REG_TIM_CLK_COF2 |
ABB5ZES3_REG_TIM_CLK_TBM | ABB5ZES3_REG_TIM_CLK_TAM);
ret = regmap_update_bits(regmap, ABB5ZES3_REG_TIM_CLK, mask,
ABB5ZES3_REG_TIM_CLK_COF0 | ABB5ZES3_REG_TIM_CLK_COF1 |
ABB5ZES3_REG_TIM_CLK_COF2);
if (ret < 0) {
dev_err(dev, "%s: unable to initialize clkout register (%d)\n",
__func__, ret);
return ret;
}
/*
* Each component of the alarm (MN, HR, DT, DW) can be enabled/disabled
* individually by clearing/setting MSB of each associated register. So,
* we set all alarm enable bits to disable current alarm setting.
*/
mask = (ABB5ZES3_REG_ALRM_MN_AE | ABB5ZES3_REG_ALRM_HR_AE |
ABB5ZES3_REG_ALRM_DT_AE | ABB5ZES3_REG_ALRM_DW_AE);
ret = regmap_update_bits(regmap, ABB5ZES3_REG_CTRL2, mask, mask);
if (ret < 0) {
dev_err(dev, "%s: unable to disable alarm setting (%d)\n",
__func__, ret);
return ret;
}
/* Set Control 1 register (RTC enabled, 24hr mode, all int. disabled) */
mask = (ABB5ZES3_REG_CTRL1_CIE | ABB5ZES3_REG_CTRL1_AIE |
ABB5ZES3_REG_CTRL1_SIE | ABB5ZES3_REG_CTRL1_PM |
ABB5ZES3_REG_CTRL1_CAP | ABB5ZES3_REG_CTRL1_STOP);
ret = regmap_update_bits(regmap, ABB5ZES3_REG_CTRL1, mask, 0);
if (ret < 0) {
dev_err(dev, "%s: unable to initialize CTRL1 register (%d)\n",
__func__, ret);
return ret;
}
/*
* Set Control 2 register (timer int. disabled, alarm status cleared).
* WTAF is read-only and cleared automatically by reading the register.
*/
mask = (ABB5ZES3_REG_CTRL2_CTBIE | ABB5ZES3_REG_CTRL2_CTAIE |
ABB5ZES3_REG_CTRL2_WTAIE | ABB5ZES3_REG_CTRL2_AF |
ABB5ZES3_REG_CTRL2_SF | ABB5ZES3_REG_CTRL2_CTBF |
ABB5ZES3_REG_CTRL2_CTAF);
ret = regmap_update_bits(regmap, ABB5ZES3_REG_CTRL2, mask, 0);
if (ret < 0) {
dev_err(dev, "%s: unable to initialize CTRL2 register (%d)\n",
__func__, ret);
return ret;
}
/*
* Enable battery low detection function and battery switchover function
* (standard mode). Disable associated interrupts. Clear battery
* switchover flag but not battery low flag. The latter is checked
* later below.
*/
mask = (ABB5ZES3_REG_CTRL3_PM0 | ABB5ZES3_REG_CTRL3_PM1 |
ABB5ZES3_REG_CTRL3_PM2 | ABB5ZES3_REG_CTRL3_BLIE |
ABB5ZES3_REG_CTRL3_BSIE| ABB5ZES3_REG_CTRL3_BSF);
ret = regmap_update_bits(regmap, ABB5ZES3_REG_CTRL3, mask, 0);
if (ret < 0) {
dev_err(dev, "%s: unable to initialize CTRL3 register (%d)\n",
__func__, ret);
return ret;
}
/* Check oscillator integrity flag */
ret = regmap_read(regmap, ABB5ZES3_REG_RTC_SC, &reg);
if (ret < 0) {
dev_err(dev, "%s: unable to read osc. integrity flag (%d)\n",
__func__, ret);
return ret;
}
if (reg & ABB5ZES3_REG_RTC_SC_OSC) {
dev_err(dev, "clock integrity not guaranteed. Osc. has stopped "
"or has been interrupted.\n");
dev_err(dev, "change battery (if not already done) and "
"then set time to reset osc. failure flag.\n");
}
/*
* Check battery low flag at startup: this allows reporting battery
* is low at startup when IRQ line is not connected. Note: we record
* current status to avoid reenabling this interrupt later in probe
* function if battery is low.
*/
ret = regmap_read(regmap, ABB5ZES3_REG_CTRL3, &reg);
if (ret < 0) {
dev_err(dev, "%s: unable to read battery low flag (%d)\n",
__func__, ret);
return ret;
}
data->battery_low = reg & ABB5ZES3_REG_CTRL3_BLF;
if (data->battery_low) {
dev_err(dev, "RTC battery is low; please, consider "
"changing it!\n");
ret = _abb5zes3_rtc_battery_low_irq_enable(regmap, false);
if (ret)
dev_err(dev, "%s: disabling battery low interrupt "
"generation failed (%d)\n", __func__, ret);
}
return ret;
}
static int abb5zes3_rtc_alarm_irq_enable(struct device *dev,
unsigned int enable)
{
struct abb5zes3_rtc_data *rtc_data = dev_get_drvdata(dev);
int ret = 0;
if (rtc_data->irq) {
mutex_lock(&rtc_data->lock);
if (rtc_data->timer_alarm)
ret = _abb5zes3_rtc_update_timer(dev, enable);
else
ret = _abb5zes3_rtc_update_alarm(dev, enable);
mutex_unlock(&rtc_data->lock);
}
return ret;
}
static irqreturn_t _abb5zes3_rtc_interrupt(int irq, void *data)
{
struct i2c_client *client = data;
struct device *dev = &client->dev;
struct abb5zes3_rtc_data *rtc_data = dev_get_drvdata(dev);
struct rtc_device *rtc = rtc_data->rtc;
u8 regs[ABB5ZES3_CTRL_SEC_LEN];
int ret, handled = IRQ_NONE;
ret = regmap_bulk_read(rtc_data->regmap, 0, regs,
ABB5ZES3_CTRL_SEC_LEN);
if (ret) {
dev_err(dev, "%s: unable to read control section (%d)!\n",
__func__, ret);
return handled;
}
/*
* Check battery low detection flag and disable battery low interrupt
* generation if flag is set (interrupt can only be cleared when
* battery is replaced).
*/
if (regs[ABB5ZES3_REG_CTRL3] & ABB5ZES3_REG_CTRL3_BLF) {
dev_err(dev, "RTC battery is low; please change it!\n");
_abb5zes3_rtc_battery_low_irq_enable(rtc_data->regmap, false);
handled = IRQ_HANDLED;
}
/* Check alarm flag */
if (regs[ABB5ZES3_REG_CTRL2] & ABB5ZES3_REG_CTRL2_AF) {
dev_dbg(dev, "RTC alarm!\n");
rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
/* Acknowledge and disable the alarm */
_abb5zes3_rtc_clear_alarm(dev);
_abb5zes3_rtc_update_alarm(dev, 0);
handled = IRQ_HANDLED;
}
/* Check watchdog Timer A flag */
if (regs[ABB5ZES3_REG_CTRL2] & ABB5ZES3_REG_CTRL2_WTAF) {
dev_dbg(dev, "RTC timer!\n");
rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
/*
* Acknowledge and disable the alarm. Note: WTAF
* flag had been cleared when reading CTRL2
*/
_abb5zes3_rtc_update_timer(dev, 0);
rtc_data->timer_alarm = 0;
handled = IRQ_HANDLED;
}
return handled;
}
static const struct rtc_class_ops rtc_ops = {
.read_time = _abb5zes3_rtc_read_time,
.set_time = abb5zes3_rtc_set_time,
.read_alarm = abb5zes3_rtc_read_alarm,
.set_alarm = abb5zes3_rtc_set_alarm,
.alarm_irq_enable = abb5zes3_rtc_alarm_irq_enable,
};
static const struct regmap_config abb5zes3_rtc_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
};
static int abb5zes3_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct abb5zes3_rtc_data *data = NULL;
struct device *dev = &client->dev;
struct regmap *regmap;
int ret;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_I2C_BLOCK)) {
ret = -ENODEV;
goto err;
}
regmap = devm_regmap_init_i2c(client, &abb5zes3_rtc_regmap_config);
if (IS_ERR(regmap)) {
ret = PTR_ERR(regmap);
dev_err(dev, "%s: regmap allocation failed: %d\n",
__func__, ret);
goto err;
}
ret = abb5zes3_i2c_validate_chip(regmap);
if (ret)
goto err;
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!data) {
ret = -ENOMEM;
goto err;
}
mutex_init(&data->lock);
data->regmap = regmap;
dev_set_drvdata(dev, data);
ret = abb5zes3_rtc_check_setup(dev);
if (ret)
goto err;
if (client->irq > 0) {
ret = devm_request_threaded_irq(dev, client->irq, NULL,
_abb5zes3_rtc_interrupt,
IRQF_SHARED|IRQF_ONESHOT,
DRV_NAME, client);
if (!ret) {
device_init_wakeup(dev, true);
data->irq = client->irq;
dev_dbg(dev, "%s: irq %d used by RTC\n", __func__,
client->irq);
} else {
dev_err(dev, "%s: irq %d unavailable (%d)\n",
__func__, client->irq, ret);
goto err;
}
}
data->rtc = devm_rtc_device_register(dev, DRV_NAME, &rtc_ops,
THIS_MODULE);
ret = PTR_ERR_OR_ZERO(data->rtc);
if (ret) {
dev_err(dev, "%s: unable to register RTC device (%d)\n",
__func__, ret);
goto err;
}
/* Enable battery low detection interrupt if battery not already low */
if (!data->battery_low && data->irq) {
ret = _abb5zes3_rtc_battery_low_irq_enable(regmap, true);
if (ret) {
dev_err(dev, "%s: enabling battery low interrupt "
"generation failed (%d)\n", __func__, ret);
goto err;
}
}
err:
if (ret && data && data->irq)
device_init_wakeup(dev, false);
return ret;
}
static int abb5zes3_remove(struct i2c_client *client)
{
struct abb5zes3_rtc_data *rtc_data = dev_get_drvdata(&client->dev);
if (rtc_data->irq > 0)
device_init_wakeup(&client->dev, false);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int abb5zes3_rtc_suspend(struct device *dev)
{
struct abb5zes3_rtc_data *rtc_data = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
return enable_irq_wake(rtc_data->irq);
return 0;
}
static int abb5zes3_rtc_resume(struct device *dev)
{
struct abb5zes3_rtc_data *rtc_data = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
return disable_irq_wake(rtc_data->irq);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(abb5zes3_rtc_pm_ops, abb5zes3_rtc_suspend,
abb5zes3_rtc_resume);
#ifdef CONFIG_OF
static const struct of_device_id abb5zes3_dt_match[] = {
{ .compatible = "abracon,abb5zes3" },
{ },
};
MODULE_DEVICE_TABLE(of, abb5zes3_dt_match);
#endif
static const struct i2c_device_id abb5zes3_id[] = {
{ "abb5zes3", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, abb5zes3_id);
static struct i2c_driver abb5zes3_driver = {
.driver = {
.name = DRV_NAME,
.pm = &abb5zes3_rtc_pm_ops,
.of_match_table = of_match_ptr(abb5zes3_dt_match),
},
.probe = abb5zes3_probe,
.remove = abb5zes3_remove,
.id_table = abb5zes3_id,
};
module_i2c_driver(abb5zes3_driver);
MODULE_AUTHOR("Arnaud EBALARD <arno@natisbad.org>");
MODULE_DESCRIPTION("Abracon AB-RTCMC-32.768kHz-B5ZE-S3 RTC/Alarm driver");
MODULE_LICENSE("GPL");
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