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e5480701d3
kernel/drivers/rtc/rtc-pcf2127.c
tqcq e5480701d3 init repo.
2024-07-22 17:22:30 +08:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* An I2C and SPI driver for the NXP PCF2127/29 RTC
* Copyright 2013 Til-Technologies
*
* Author: Renaud Cerrato <r.cerrato@til-technologies.fr>
*
* Watchdog and tamper functions
* Author: Bruno Thomsen <bruno.thomsen@gmail.com>
*
* based on the other drivers in this same directory.
*
* Datasheet: https://www.nxp.com/docs/en/data-sheet/PCF2127.pdf
*/
#include <linux/i2c.h>
#include <linux/spi/spi.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/regmap.h>
#include <linux/watchdog.h>
/* Control register 1 */
#define PCF2127_REG_CTRL1 0x00
#define PCF2127_BIT_CTRL1_POR_OVRD BIT(3)
#define PCF2127_BIT_CTRL1_TSF1 BIT(4)
/* Control register 2 */
#define PCF2127_REG_CTRL2 0x01
#define PCF2127_BIT_CTRL2_AIE BIT(1)
#define PCF2127_BIT_CTRL2_TSIE BIT(2)
#define PCF2127_BIT_CTRL2_AF BIT(4)
#define PCF2127_BIT_CTRL2_TSF2 BIT(5)
#define PCF2127_BIT_CTRL2_WDTF BIT(6)
/* Control register 3 */
#define PCF2127_REG_CTRL3 0x02
#define PCF2127_BIT_CTRL3_BLIE BIT(0)
#define PCF2127_BIT_CTRL3_BIE BIT(1)
#define PCF2127_BIT_CTRL3_BLF BIT(2)
#define PCF2127_BIT_CTRL3_BF BIT(3)
#define PCF2127_BIT_CTRL3_BTSE BIT(4)
/* Time and date registers */
#define PCF2127_REG_SC 0x03
#define PCF2127_BIT_SC_OSF BIT(7)
#define PCF2127_REG_MN 0x04
#define PCF2127_REG_HR 0x05
#define PCF2127_REG_DM 0x06
#define PCF2127_REG_DW 0x07
#define PCF2127_REG_MO 0x08
#define PCF2127_REG_YR 0x09
/* Alarm registers */
#define PCF2127_REG_ALARM_SC 0x0A
#define PCF2127_REG_ALARM_MN 0x0B
#define PCF2127_REG_ALARM_HR 0x0C
#define PCF2127_REG_ALARM_DM 0x0D
#define PCF2127_REG_ALARM_DW 0x0E
#define PCF2127_BIT_ALARM_AE BIT(7)
/* CLKOUT control register */
#define PCF2127_REG_CLKOUT 0x0f
#define PCF2127_BIT_CLKOUT_OTPR BIT(5)
/* Watchdog registers */
#define PCF2127_REG_WD_CTL 0x10
#define PCF2127_BIT_WD_CTL_TF0 BIT(0)
#define PCF2127_BIT_WD_CTL_TF1 BIT(1)
#define PCF2127_BIT_WD_CTL_CD0 BIT(6)
#define PCF2127_BIT_WD_CTL_CD1 BIT(7)
#define PCF2127_REG_WD_VAL 0x11
/* Tamper timestamp registers */
#define PCF2127_REG_TS_CTRL 0x12
#define PCF2127_BIT_TS_CTRL_TSOFF BIT(6)
#define PCF2127_BIT_TS_CTRL_TSM BIT(7)
#define PCF2127_REG_TS_SC 0x13
#define PCF2127_REG_TS_MN 0x14
#define PCF2127_REG_TS_HR 0x15
#define PCF2127_REG_TS_DM 0x16
#define PCF2127_REG_TS_MO 0x17
#define PCF2127_REG_TS_YR 0x18
/*
* RAM registers
* PCF2127 has 512 bytes general-purpose static RAM (SRAM) that is
* battery backed and can survive a power outage.
* PCF2129 doesn't have this feature.
*/
#define PCF2127_REG_RAM_ADDR_MSB 0x1A
#define PCF2127_REG_RAM_WRT_CMD 0x1C
#define PCF2127_REG_RAM_RD_CMD 0x1D
/* Watchdog timer value constants */
#define PCF2127_WD_VAL_STOP 0
#define PCF2127_WD_VAL_MIN 2
#define PCF2127_WD_VAL_MAX 255
#define PCF2127_WD_VAL_DEFAULT 60
/* Mask for currently enabled interrupts */
#define PCF2127_CTRL1_IRQ_MASK (PCF2127_BIT_CTRL1_TSF1)
#define PCF2127_CTRL2_IRQ_MASK ( \
PCF2127_BIT_CTRL2_AF | \
PCF2127_BIT_CTRL2_WDTF | \
PCF2127_BIT_CTRL2_TSF2)
struct pcf2127 {
struct rtc_device *rtc;
struct watchdog_device wdd;
struct regmap *regmap;
time64_t ts;
bool ts_valid;
bool irq_enabled;
};
/*
* In the routines that deal directly with the pcf2127 hardware, we use
* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
*/
static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
unsigned char buf[10];
int ret;
/*
* Avoid reading CTRL2 register as it causes WD_VAL register
* value to reset to 0 which means watchdog is stopped.
*/
ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_CTRL3,
(buf + PCF2127_REG_CTRL3),
ARRAY_SIZE(buf) - PCF2127_REG_CTRL3);
if (ret) {
dev_err(dev, "%s: read error\n", __func__);
return ret;
}
if (buf[PCF2127_REG_CTRL3] & PCF2127_BIT_CTRL3_BLF)
dev_info(dev,
"low voltage detected, check/replace RTC battery.\n");
/* Clock integrity is not guaranteed when OSF flag is set. */
if (buf[PCF2127_REG_SC] & PCF2127_BIT_SC_OSF) {
/*
* no need clear the flag here,
* it will be cleared once the new date is saved
*/
dev_warn(dev,
"oscillator stop detected, date/time is not reliable\n");
return -EINVAL;
}
dev_dbg(dev,
"%s: raw data is cr3=%02x, sec=%02x, min=%02x, hr=%02x, "
"mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
__func__, buf[PCF2127_REG_CTRL3], buf[PCF2127_REG_SC],
buf[PCF2127_REG_MN], buf[PCF2127_REG_HR],
buf[PCF2127_REG_DM], buf[PCF2127_REG_DW],
buf[PCF2127_REG_MO], buf[PCF2127_REG_YR]);
tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F); /* rtc hr 0-23 */
tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]);
tm->tm_year += 100;
dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
"mday=%d, mon=%d, year=%d, wday=%d\n",
__func__,
tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
return 0;
}
static int pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
unsigned char buf[7];
int i = 0, err;
dev_dbg(dev, "%s: secs=%d, mins=%d, hours=%d, "
"mday=%d, mon=%d, year=%d, wday=%d\n",
__func__,
tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
/* hours, minutes and seconds */
buf[i++] = bin2bcd(tm->tm_sec); /* this will also clear OSF flag */
buf[i++] = bin2bcd(tm->tm_min);
buf[i++] = bin2bcd(tm->tm_hour);
buf[i++] = bin2bcd(tm->tm_mday);
buf[i++] = tm->tm_wday & 0x07;
/* month, 1 - 12 */
buf[i++] = bin2bcd(tm->tm_mon + 1);
/* year */
buf[i++] = bin2bcd(tm->tm_year - 100);
/* write register's data */
err = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_SC, buf, i);
if (err) {
dev_err(dev,
"%s: err=%d", __func__, err);
return err;
}
return 0;
}
static int pcf2127_rtc_ioctl(struct device *dev,
unsigned int cmd, unsigned long arg)
{
struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
int val, touser = 0;
int ret;
switch (cmd) {
case RTC_VL_READ:
ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL3, &val);
if (ret)
return ret;
if (val & PCF2127_BIT_CTRL3_BLF)
touser |= RTC_VL_BACKUP_LOW;
if (val & PCF2127_BIT_CTRL3_BF)
touser |= RTC_VL_BACKUP_SWITCH;
return put_user(touser, (unsigned int __user *)arg);
case RTC_VL_CLR:
return regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL3,
PCF2127_BIT_CTRL3_BF, 0);
default:
return -ENOIOCTLCMD;
}
}
static int pcf2127_nvmem_read(void *priv, unsigned int offset,
void *val, size_t bytes)
{
struct pcf2127 *pcf2127 = priv;
int ret;
unsigned char offsetbuf[] = { offset >> 8, offset };
ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_ADDR_MSB,
offsetbuf, 2);
if (ret)
return ret;
return regmap_bulk_read(pcf2127->regmap, PCF2127_REG_RAM_RD_CMD,
val, bytes);
}
static int pcf2127_nvmem_write(void *priv, unsigned int offset,
void *val, size_t bytes)
{
struct pcf2127 *pcf2127 = priv;
int ret;
unsigned char offsetbuf[] = { offset >> 8, offset };
ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_ADDR_MSB,
offsetbuf, 2);
if (ret)
return ret;
return regmap_bulk_write(pcf2127->regmap, PCF2127_REG_RAM_WRT_CMD,
val, bytes);
}
/* watchdog driver */
static int pcf2127_wdt_ping(struct watchdog_device *wdd)
{
struct pcf2127 *pcf2127 = watchdog_get_drvdata(wdd);
return regmap_write(pcf2127->regmap, PCF2127_REG_WD_VAL, wdd->timeout);
}
/*
* Restart watchdog timer if feature is active.
*
* Note: Reading CTRL2 register causes watchdog to stop which is unfortunate,
* since register also contain control/status flags for other features.
* Always call this function after reading CTRL2 register.
*/
static int pcf2127_wdt_active_ping(struct watchdog_device *wdd)
{
int ret = 0;
if (watchdog_active(wdd)) {
ret = pcf2127_wdt_ping(wdd);
if (ret)
dev_err(wdd->parent,
"%s: watchdog restart failed, ret=%d\n",
__func__, ret);
}
return ret;
}
static int pcf2127_wdt_start(struct watchdog_device *wdd)
{
return pcf2127_wdt_ping(wdd);
}
static int pcf2127_wdt_stop(struct watchdog_device *wdd)
{
struct pcf2127 *pcf2127 = watchdog_get_drvdata(wdd);
return regmap_write(pcf2127->regmap, PCF2127_REG_WD_VAL,
PCF2127_WD_VAL_STOP);
}
static int pcf2127_wdt_set_timeout(struct watchdog_device *wdd,
unsigned int new_timeout)
{
dev_dbg(wdd->parent, "new watchdog timeout: %is (old: %is)\n",
new_timeout, wdd->timeout);
wdd->timeout = new_timeout;
return pcf2127_wdt_active_ping(wdd);
}
static const struct watchdog_info pcf2127_wdt_info = {
.identity = "NXP PCF2127/PCF2129 Watchdog",
.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT,
};
static const struct watchdog_ops pcf2127_watchdog_ops = {
.owner = THIS_MODULE,
.start = pcf2127_wdt_start,
.stop = pcf2127_wdt_stop,
.ping = pcf2127_wdt_ping,
.set_timeout = pcf2127_wdt_set_timeout,
};
static int pcf2127_watchdog_init(struct device *dev, struct pcf2127 *pcf2127)
{
u32 wdd_timeout;
int ret;
if (!IS_ENABLED(CONFIG_WATCHDOG) ||
!device_property_read_bool(dev, "reset-source"))
return 0;
pcf2127->wdd.parent = dev;
pcf2127->wdd.info = &pcf2127_wdt_info;
pcf2127->wdd.ops = &pcf2127_watchdog_ops;
pcf2127->wdd.min_timeout = PCF2127_WD_VAL_MIN;
pcf2127->wdd.max_timeout = PCF2127_WD_VAL_MAX;
pcf2127->wdd.timeout = PCF2127_WD_VAL_DEFAULT;
pcf2127->wdd.min_hw_heartbeat_ms = 500;
pcf2127->wdd.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
watchdog_set_drvdata(&pcf2127->wdd, pcf2127);
/* Test if watchdog timer is started by bootloader */
ret = regmap_read(pcf2127->regmap, PCF2127_REG_WD_VAL, &wdd_timeout);
if (ret)
return ret;
if (wdd_timeout)
set_bit(WDOG_HW_RUNNING, &pcf2127->wdd.status);
return devm_watchdog_register_device(dev, &pcf2127->wdd);
}
/* Alarm */
static int pcf2127_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
u8 buf[5];
unsigned int ctrl2;
int ret;
ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL2, &ctrl2);
if (ret)
return ret;
ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
if (ret)
return ret;
ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_ALARM_SC, buf,
sizeof(buf));
if (ret)
return ret;
alrm->enabled = ctrl2 & PCF2127_BIT_CTRL2_AIE;
alrm->pending = ctrl2 & PCF2127_BIT_CTRL2_AF;
alrm->time.tm_sec = bcd2bin(buf[0] & 0x7F);
alrm->time.tm_min = bcd2bin(buf[1] & 0x7F);
alrm->time.tm_hour = bcd2bin(buf[2] & 0x3F);
alrm->time.tm_mday = bcd2bin(buf[3] & 0x3F);
return 0;
}
static int pcf2127_rtc_alarm_irq_enable(struct device *dev, u32 enable)
{
struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
int ret;
ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL2,
PCF2127_BIT_CTRL2_AIE,
enable ? PCF2127_BIT_CTRL2_AIE : 0);
if (ret)
return ret;
return pcf2127_wdt_active_ping(&pcf2127->wdd);
}
static int pcf2127_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
uint8_t buf[5];
int ret;
ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL2,
PCF2127_BIT_CTRL2_AF, 0);
if (ret)
return ret;
ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
if (ret)
return ret;
buf[0] = bin2bcd(alrm->time.tm_sec);
buf[1] = bin2bcd(alrm->time.tm_min);
buf[2] = bin2bcd(alrm->time.tm_hour);
buf[3] = bin2bcd(alrm->time.tm_mday);
buf[4] = PCF2127_BIT_ALARM_AE; /* Do not match on week day */
ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_ALARM_SC, buf,
sizeof(buf));
if (ret)
return ret;
return pcf2127_rtc_alarm_irq_enable(dev, alrm->enabled);
}
/*
* This function reads ctrl2 register, caller is responsible for calling
* pcf2127_wdt_active_ping()
*/
static int pcf2127_rtc_ts_read(struct device *dev, time64_t *ts)
{
struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
struct rtc_time tm;
int ret;
unsigned char data[25];
ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_CTRL1, data,
sizeof(data));
if (ret) {
dev_err(dev, "%s: read error ret=%d\n", __func__, ret);
return ret;
}
dev_dbg(dev,
"%s: raw data is cr1=%02x, cr2=%02x, cr3=%02x, ts_sc=%02x, ts_mn=%02x, ts_hr=%02x, ts_dm=%02x, ts_mo=%02x, ts_yr=%02x\n",
__func__, data[PCF2127_REG_CTRL1], data[PCF2127_REG_CTRL2],
data[PCF2127_REG_CTRL3], data[PCF2127_REG_TS_SC],
data[PCF2127_REG_TS_MN], data[PCF2127_REG_TS_HR],
data[PCF2127_REG_TS_DM], data[PCF2127_REG_TS_MO],
data[PCF2127_REG_TS_YR]);
tm.tm_sec = bcd2bin(data[PCF2127_REG_TS_SC] & 0x7F);
tm.tm_min = bcd2bin(data[PCF2127_REG_TS_MN] & 0x7F);
tm.tm_hour = bcd2bin(data[PCF2127_REG_TS_HR] & 0x3F);
tm.tm_mday = bcd2bin(data[PCF2127_REG_TS_DM] & 0x3F);
/* TS_MO register (month) value range: 1-12 */
tm.tm_mon = bcd2bin(data[PCF2127_REG_TS_MO] & 0x1F) - 1;
tm.tm_year = bcd2bin(data[PCF2127_REG_TS_YR]);
if (tm.tm_year < 70)
tm.tm_year += 100; /* assume we are in 1970...2069 */
ret = rtc_valid_tm(&tm);
if (ret) {
dev_err(dev, "Invalid timestamp. ret=%d\n", ret);
return ret;
}
*ts = rtc_tm_to_time64(&tm);
return 0;
};
static void pcf2127_rtc_ts_snapshot(struct device *dev)
{
struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
int ret;
/* Let userspace read the first timestamp */
if (pcf2127->ts_valid)
return;
ret = pcf2127_rtc_ts_read(dev, &pcf2127->ts);
if (!ret)
pcf2127->ts_valid = true;
}
static irqreturn_t pcf2127_rtc_irq(int irq, void *dev)
{
struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
unsigned int ctrl1, ctrl2;
int ret = 0;
ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL1, &ctrl1);
if (ret)
return IRQ_NONE;
ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL2, &ctrl2);
if (ret)
return IRQ_NONE;
if (!(ctrl1 & PCF2127_CTRL1_IRQ_MASK || ctrl2 & PCF2127_CTRL2_IRQ_MASK))
return IRQ_NONE;
if (ctrl1 & PCF2127_BIT_CTRL1_TSF1 || ctrl2 & PCF2127_BIT_CTRL2_TSF2)
pcf2127_rtc_ts_snapshot(dev);
if (ctrl1 & PCF2127_CTRL1_IRQ_MASK)
regmap_write(pcf2127->regmap, PCF2127_REG_CTRL1,
ctrl1 & ~PCF2127_CTRL1_IRQ_MASK);
if (ctrl2 & PCF2127_CTRL2_IRQ_MASK)
regmap_write(pcf2127->regmap, PCF2127_REG_CTRL2,
ctrl2 & ~PCF2127_CTRL2_IRQ_MASK);
if (ctrl2 & PCF2127_BIT_CTRL2_AF)
rtc_update_irq(pcf2127->rtc, 1, RTC_IRQF | RTC_AF);
pcf2127_wdt_active_ping(&pcf2127->wdd);
return IRQ_HANDLED;
}
static const struct rtc_class_ops pcf2127_rtc_ops = {
.ioctl = pcf2127_rtc_ioctl,
.read_time = pcf2127_rtc_read_time,
.set_time = pcf2127_rtc_set_time,
.read_alarm = pcf2127_rtc_read_alarm,
.set_alarm = pcf2127_rtc_set_alarm,
.alarm_irq_enable = pcf2127_rtc_alarm_irq_enable,
};
/* sysfs interface */
static ssize_t timestamp0_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct pcf2127 *pcf2127 = dev_get_drvdata(dev->parent);
int ret;
if (pcf2127->irq_enabled) {
pcf2127->ts_valid = false;
} else {
ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL1,
PCF2127_BIT_CTRL1_TSF1, 0);
if (ret) {
dev_err(dev, "%s: update ctrl1 ret=%d\n", __func__, ret);
return ret;
}
ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL2,
PCF2127_BIT_CTRL2_TSF2, 0);
if (ret) {
dev_err(dev, "%s: update ctrl2 ret=%d\n", __func__, ret);
return ret;
}
ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
if (ret)
return ret;
}
return count;
};
static ssize_t timestamp0_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct pcf2127 *pcf2127 = dev_get_drvdata(dev->parent);
unsigned int ctrl1, ctrl2;
int ret;
time64_t ts;
if (pcf2127->irq_enabled) {
if (!pcf2127->ts_valid)
return 0;
ts = pcf2127->ts;
} else {
ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL1, &ctrl1);
if (ret)
return 0;
ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL2, &ctrl2);
if (ret)
return 0;
if (!(ctrl1 & PCF2127_BIT_CTRL1_TSF1) &&
!(ctrl2 & PCF2127_BIT_CTRL2_TSF2))
return 0;
ret = pcf2127_rtc_ts_read(dev->parent, &ts);
if (ret)
return 0;
ret = pcf2127_wdt_active_ping(&pcf2127->wdd);
if (ret)
return ret;
}
return sprintf(buf, "%llu\n", (unsigned long long)ts);
};
static DEVICE_ATTR_RW(timestamp0);
static struct attribute *pcf2127_attrs[] = {
&dev_attr_timestamp0.attr,
NULL
};
static const struct attribute_group pcf2127_attr_group = {
.attrs = pcf2127_attrs,
};
static int pcf2127_probe(struct device *dev, struct regmap *regmap,
int alarm_irq, const char *name, bool is_pcf2127)
{
struct pcf2127 *pcf2127;
int ret = 0;
unsigned int val;
dev_dbg(dev, "%s\n", __func__);
pcf2127 = devm_kzalloc(dev, sizeof(*pcf2127), GFP_KERNEL);
if (!pcf2127)
return -ENOMEM;
pcf2127->regmap = regmap;
dev_set_drvdata(dev, pcf2127);
pcf2127->rtc = devm_rtc_allocate_device(dev);
if (IS_ERR(pcf2127->rtc))
return PTR_ERR(pcf2127->rtc);
pcf2127->rtc->ops = &pcf2127_rtc_ops;
pcf2127->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
pcf2127->rtc->range_max = RTC_TIMESTAMP_END_2099;
pcf2127->rtc->set_start_time = true; /* Sets actual start to 1970 */
pcf2127->rtc->uie_unsupported = 1;
clear_bit(RTC_FEATURE_ALARM, pcf2127->rtc->features);
if (alarm_irq > 0) {
ret = devm_request_threaded_irq(dev, alarm_irq, NULL,
pcf2127_rtc_irq,
IRQF_TRIGGER_LOW | IRQF_ONESHOT,
dev_name(dev), dev);
if (ret) {
dev_err(dev, "failed to request alarm irq\n");
return ret;
}
pcf2127->irq_enabled = true;
}
if (alarm_irq > 0 || device_property_read_bool(dev, "wakeup-source")) {
device_init_wakeup(dev, true);
set_bit(RTC_FEATURE_ALARM, pcf2127->rtc->features);
}
if (is_pcf2127) {
struct nvmem_config nvmem_cfg = {
.priv = pcf2127,
.reg_read = pcf2127_nvmem_read,
.reg_write = pcf2127_nvmem_write,
.size = 512,
};
ret = devm_rtc_nvmem_register(pcf2127->rtc, &nvmem_cfg);
}
/*
* The "Power-On Reset Override" facility prevents the RTC to do a reset
* after power on. For normal operation the PORO must be disabled.
*/
regmap_clear_bits(pcf2127->regmap, PCF2127_REG_CTRL1,
PCF2127_BIT_CTRL1_POR_OVRD);
ret = regmap_read(pcf2127->regmap, PCF2127_REG_CLKOUT, &val);
if (ret < 0)
return ret;
if (!(val & PCF2127_BIT_CLKOUT_OTPR)) {
ret = regmap_set_bits(pcf2127->regmap, PCF2127_REG_CLKOUT,
PCF2127_BIT_CLKOUT_OTPR);
if (ret < 0)
return ret;
msleep(100);
}
/*
* Watchdog timer enabled and reset pin /RST activated when timed out.
* Select 1Hz clock source for watchdog timer.
* Note: Countdown timer disabled and not available.
* For pca2129, pcf2129, only bit[7] is for Symbol WD_CD
* of register watchdg_tim_ctl. The bit[6] is labeled
* as T. Bits labeled as T must always be written with
* logic 0.
*/
ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_WD_CTL,
PCF2127_BIT_WD_CTL_CD1 |
PCF2127_BIT_WD_CTL_CD0 |
PCF2127_BIT_WD_CTL_TF1 |
PCF2127_BIT_WD_CTL_TF0,
PCF2127_BIT_WD_CTL_CD1 |
(is_pcf2127 ? PCF2127_BIT_WD_CTL_CD0 : 0) |
PCF2127_BIT_WD_CTL_TF1);
if (ret) {
dev_err(dev, "%s: watchdog config (wd_ctl) failed\n", __func__);
return ret;
}
pcf2127_watchdog_init(dev, pcf2127);
/*
* Disable battery low/switch-over timestamp and interrupts.
* Clear battery interrupt flags which can block new trigger events.
* Note: This is the default chip behaviour but added to ensure
* correct tamper timestamp and interrupt function.
*/
ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL3,
PCF2127_BIT_CTRL3_BTSE |
PCF2127_BIT_CTRL3_BIE |
PCF2127_BIT_CTRL3_BLIE, 0);
if (ret) {
dev_err(dev, "%s: interrupt config (ctrl3) failed\n",
__func__);
return ret;
}
/*
* Enable timestamp function and store timestamp of first trigger
* event until TSF1 and TFS2 interrupt flags are cleared.
*/
ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_TS_CTRL,
PCF2127_BIT_TS_CTRL_TSOFF |
PCF2127_BIT_TS_CTRL_TSM,
PCF2127_BIT_TS_CTRL_TSM);
if (ret) {
dev_err(dev, "%s: tamper detection config (ts_ctrl) failed\n",
__func__);
return ret;
}
/*
* Enable interrupt generation when TSF1 or TSF2 timestamp flags
* are set. Interrupt signal is an open-drain output and can be
* left floating if unused.
*/
ret = regmap_update_bits(pcf2127->regmap, PCF2127_REG_CTRL2,
PCF2127_BIT_CTRL2_TSIE,
PCF2127_BIT_CTRL2_TSIE);
if (ret) {
dev_err(dev, "%s: tamper detection config (ctrl2) failed\n",
__func__);
return ret;
}
ret = rtc_add_group(pcf2127->rtc, &pcf2127_attr_group);
if (ret) {
dev_err(dev, "%s: tamper sysfs registering failed\n",
__func__);
return ret;
}
return devm_rtc_register_device(pcf2127->rtc);
}
#ifdef CONFIG_OF
static const struct of_device_id pcf2127_of_match[] = {
{ .compatible = "nxp,pcf2127" },
{ .compatible = "nxp,pcf2129" },
{ .compatible = "nxp,pca2129" },
{}
};
MODULE_DEVICE_TABLE(of, pcf2127_of_match);
#endif
#if IS_ENABLED(CONFIG_I2C)
static int pcf2127_i2c_write(void *context, const void *data, size_t count)
{
struct device *dev = context;
struct i2c_client *client = to_i2c_client(dev);
int ret;
ret = i2c_master_send(client, data, count);
if (ret != count)
return ret < 0 ? ret : -EIO;
return 0;
}
static int pcf2127_i2c_gather_write(void *context,
const void *reg, size_t reg_size,
const void *val, size_t val_size)
{
struct device *dev = context;
struct i2c_client *client = to_i2c_client(dev);
int ret;
void *buf;
if (WARN_ON(reg_size != 1))
return -EINVAL;
buf = kmalloc(val_size + 1, GFP_KERNEL);
if (!buf)
return -ENOMEM;
memcpy(buf, reg, 1);
memcpy(buf + 1, val, val_size);
ret = i2c_master_send(client, buf, val_size + 1);
kfree(buf);
if (ret != val_size + 1)
return ret < 0 ? ret : -EIO;
return 0;
}
static int pcf2127_i2c_read(void *context, const void *reg, size_t reg_size,
void *val, size_t val_size)
{
struct device *dev = context;
struct i2c_client *client = to_i2c_client(dev);
int ret;
if (WARN_ON(reg_size != 1))
return -EINVAL;
ret = i2c_master_send(client, reg, 1);
if (ret != 1)
return ret < 0 ? ret : -EIO;
ret = i2c_master_recv(client, val, val_size);
if (ret != val_size)
return ret < 0 ? ret : -EIO;
return 0;
}
/*
* The reason we need this custom regmap_bus instead of using regmap_init_i2c()
* is that the STOP condition is required between set register address and
* read register data when reading from registers.
*/
static const struct regmap_bus pcf2127_i2c_regmap = {
.write = pcf2127_i2c_write,
.gather_write = pcf2127_i2c_gather_write,
.read = pcf2127_i2c_read,
};
static struct i2c_driver pcf2127_i2c_driver;
static int pcf2127_i2c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct regmap *regmap;
static const struct regmap_config config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = 0x1d,
};
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
return -ENODEV;
regmap = devm_regmap_init(&client->dev, &pcf2127_i2c_regmap,
&client->dev, &config);
if (IS_ERR(regmap)) {
dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
__func__, PTR_ERR(regmap));
return PTR_ERR(regmap);
}
return pcf2127_probe(&client->dev, regmap, client->irq,
pcf2127_i2c_driver.driver.name, id->driver_data);
}
static const struct i2c_device_id pcf2127_i2c_id[] = {
{ "pcf2127", 1 },
{ "pcf2129", 0 },
{ "pca2129", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, pcf2127_i2c_id);
static struct i2c_driver pcf2127_i2c_driver = {
.driver = {
.name = "rtc-pcf2127-i2c",
.of_match_table = of_match_ptr(pcf2127_of_match),
},
.probe = pcf2127_i2c_probe,
.id_table = pcf2127_i2c_id,
};
static int pcf2127_i2c_register_driver(void)
{
return i2c_add_driver(&pcf2127_i2c_driver);
}
static void pcf2127_i2c_unregister_driver(void)
{
i2c_del_driver(&pcf2127_i2c_driver);
}
#else
static int pcf2127_i2c_register_driver(void)
{
return 0;
}
static void pcf2127_i2c_unregister_driver(void)
{
}
#endif
#if IS_ENABLED(CONFIG_SPI_MASTER)
static struct spi_driver pcf2127_spi_driver;
static int pcf2127_spi_probe(struct spi_device *spi)
{
static const struct regmap_config config = {
.reg_bits = 8,
.val_bits = 8,
.read_flag_mask = 0xa0,
.write_flag_mask = 0x20,
.max_register = 0x1d,
};
struct regmap *regmap;
regmap = devm_regmap_init_spi(spi, &config);
if (IS_ERR(regmap)) {
dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
__func__, PTR_ERR(regmap));
return PTR_ERR(regmap);
}
return pcf2127_probe(&spi->dev, regmap, spi->irq,
pcf2127_spi_driver.driver.name,
spi_get_device_id(spi)->driver_data);
}
static const struct spi_device_id pcf2127_spi_id[] = {
{ "pcf2127", 1 },
{ "pcf2129", 0 },
{ "pca2129", 0 },
{ }
};
MODULE_DEVICE_TABLE(spi, pcf2127_spi_id);
static struct spi_driver pcf2127_spi_driver = {
.driver = {
.name = "rtc-pcf2127-spi",
.of_match_table = of_match_ptr(pcf2127_of_match),
},
.probe = pcf2127_spi_probe,
.id_table = pcf2127_spi_id,
};
static int pcf2127_spi_register_driver(void)
{
return spi_register_driver(&pcf2127_spi_driver);
}
static void pcf2127_spi_unregister_driver(void)
{
spi_unregister_driver(&pcf2127_spi_driver);
}
#else
static int pcf2127_spi_register_driver(void)
{
return 0;
}
static void pcf2127_spi_unregister_driver(void)
{
}
#endif
static int __init pcf2127_init(void)
{
int ret;
ret = pcf2127_i2c_register_driver();
if (ret) {
pr_err("Failed to register pcf2127 i2c driver: %d\n", ret);
return ret;
}
ret = pcf2127_spi_register_driver();
if (ret) {
pr_err("Failed to register pcf2127 spi driver: %d\n", ret);
pcf2127_i2c_unregister_driver();
}
return ret;
}
module_init(pcf2127_init)
static void __exit pcf2127_exit(void)
{
pcf2127_spi_unregister_driver();
pcf2127_i2c_unregister_driver();
}
module_exit(pcf2127_exit)
MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>");
MODULE_DESCRIPTION("NXP PCF2127/29 RTC driver");
MODULE_LICENSE("GPL v2");
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