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linux/drivers/rtc/rtc-ab-b5ze-s3.c
Bartosz Golaszewski fdcfd85433 rtc: rework rtc_register_device() resource management 
rtc_register_device() is a managed interface but it doesn't use devres
by itself - instead it marks an rtc_device as "registered" and the devres
callback for devm_rtc_allocate_device() takes care of resource release.

This doesn't correspond with the design behind devres where managed
structures should not be aware of being managed. The correct solution
here is to register a separate devres callback for unregistering the
device.

While at it: rename rtc_register_device() to devm_rtc_register_device()
and add it to the list of managed interfaces in devres.rst. This way we
can avoid any potential confusion of driver developers who may expect
there to exist a corresponding unregister function.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201109163409.24301-8-brgl@bgdev.pl
2020-11-19 12:50:12 +01:00

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// SPDX-License-Identifier: GPL-2.0+
/*
* 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:
*
* https://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).
*
*/
#include <linux/module.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;
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.
*/
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 = 0;
/*
* 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);
return ret;
}
/* If clock integrity is not guaranteed, do not return a time value */
if (regs[ABB5ZES3_REG_RTC_SC] & ABB5ZES3_REG_RTC_SC_OSC)
return -ENODATA;
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;
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;
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);
ret = regmap_bulk_write(data->regmap, ABB5ZES3_REG_RTC_SC,
regs + ABB5ZES3_REG_RTC_SC,
ABB5ZES3_RTC_SEC_LEN);
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);
return ret;
}
/* get current time ... */
ret = _abb5zes3_rtc_read_time(dev, &rtc_tm);
if (ret)
return ret;
/* ... convert to seconds ... */
rtc_secs = rtc_tm_to_time64(&rtc_tm);
/* ... add remaining timer A time ... */
ret = sec_from_timer_a(&timer_secs, regs[1], regs[2]);
if (ret)
return ret;
/* ... and convert back. */
rtc_time64_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);
return ret;
}
alarm->enabled = !!(reg & ABB5ZES3_REG_CTRL2_WTAIE);
return 0;
}
/* 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);
return ret;
}
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)
return ret;
alarm_tm->tm_year = rtc_tm.tm_year;
alarm_tm->tm_mon = rtc_tm.tm_mon;
rtc_secs = rtc_tm_to_time64(&rtc_tm);
alarm_secs = rtc_tm_to_time64(alarm_tm);
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);
return ret;
}
alarm->enabled = !!(reg & ABB5ZES3_REG_CTRL1_AIE);
return 0;
}
/*
* 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;
if (data->timer_alarm)
ret = _abb5zes3_rtc_read_timer(dev, alarm);
else
ret = _abb5zes3_rtc_read_alarm(dev, alarm);
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;
u8 regs[ABB5ZES3_ALRM_SEC_LEN];
struct rtc_time rtc_tm;
int ret, enable = 1;
if (!alarm->enabled) {
enable = 0;
} else {
unsigned long rtc_secs, alarm_secs;
/*
* 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.
*/
ret = _abb5zes3_rtc_read_time(dev, &rtc_tm);
if (ret)
return ret;
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;
}
rtc_secs = rtc_tm_to_time64(&rtc_tm);
alarm_secs = rtc_tm_to_time64(alarm_tm);
if (alarm_secs > rtc_secs) {
dev_err(dev, "%s: alarm maximum is one month in the future (%d)\n",
__func__, ret);
return -EINVAL;
}
}
/*
* 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);
return ret;
}
/* Record currently configured alarm is not a timer */
data->timer_alarm = 0;
/* Enable or disable alarm interrupt generation */
return _abb5zes3_rtc_update_alarm(dev, enable);
}
/*
* 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__);
return ret;
}
/* 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 */
return _abb5zes3_rtc_update_timer(dev, alarm->enabled);
}
/*
* 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;
ret = _abb5zes3_rtc_read_time(dev, &rtc_tm);
if (ret)
return ret;
rtc_secs = rtc_tm_to_time64(&rtc_tm);
alarm_secs = rtc_tm_to_time64(alarm_tm);
/* 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);
return ret;
}
ret = _abb5zes3_rtc_update_timer(dev, false);
if (ret < 0) {
dev_err(dev, "%s: unable to disable timer (%d)\n", __func__,
ret);
return ret;
}
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);
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.
*/
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) {
if (rtc_data->timer_alarm)
ret = _abb5zes3_rtc_update_timer(dev, enable);
else
ret = _abb5zes3_rtc_update_alarm(dev, enable);
}
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))
return -ENODEV;
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);
return ret;
}
ret = abb5zes3_i2c_validate_chip(regmap);
if (ret)
return ret;
data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->regmap = regmap;
dev_set_drvdata(dev, data);
ret = abb5zes3_rtc_check_setup(dev);
if (ret)
return ret;
data->rtc = devm_rtc_allocate_device(dev);
ret = PTR_ERR_OR_ZERO(data->rtc);
if (ret) {
dev_err(dev, "%s: unable to allocate RTC device (%d)\n",
__func__, ret);
return ret;
}
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->ops = &rtc_ops;
data->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
data->rtc->range_max = RTC_TIMESTAMP_END_2099;
/* 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;
}
}
ret = devm_rtc_register_device(data->rtc);
err:
if (ret && data->irq)
device_init_wakeup(dev, false);
return ret;
}
#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,
.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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