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path: root/drivers/rtc/rtc-m41t80.c
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Diffstat (limited to 'drivers/rtc/rtc-m41t80.c')
-rw-r--r--drivers/rtc/rtc-m41t80.c204
1 files changed, 119 insertions, 85 deletions
diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c
index 9b70b371bd0c..740cab013f59 100644
--- a/drivers/rtc/rtc-m41t80.c
+++ b/drivers/rtc/rtc-m41t80.c
@@ -17,11 +17,12 @@
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
-#include <linux/of_device.h>
+#include <linux/of.h>
#include <linux/rtc.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/string.h>
+#include <linux/delay.h>
#ifdef CONFIG_RTC_DRV_M41T80_WDT
#include <linux/fs.h>
#include <linux/ioctl.h>
@@ -71,7 +72,7 @@
static const struct i2c_device_id m41t80_id[] = {
{ "m41t62", M41T80_FEATURE_SQ | M41T80_FEATURE_SQ_ALT },
- { "m41t65", M41T80_FEATURE_HT | M41T80_FEATURE_WD },
+ { "m41t65", M41T80_FEATURE_WD },
{ "m41t80", M41T80_FEATURE_SQ },
{ "m41t81", M41T80_FEATURE_HT | M41T80_FEATURE_SQ},
{ "m41t81s", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
@@ -85,14 +86,14 @@ static const struct i2c_device_id m41t80_id[] = {
};
MODULE_DEVICE_TABLE(i2c, m41t80_id);
-static const struct of_device_id m41t80_of_match[] = {
+static const __maybe_unused struct of_device_id m41t80_of_match[] = {
{
.compatible = "st,m41t62",
.data = (void *)(M41T80_FEATURE_SQ | M41T80_FEATURE_SQ_ALT)
},
{
.compatible = "st,m41t65",
- .data = (void *)(M41T80_FEATURE_HT | M41T80_FEATURE_WD)
+ .data = (void *)(M41T80_FEATURE_WD)
},
{
.compatible = "st,m41t80",
@@ -158,21 +159,20 @@ static irqreturn_t m41t80_handle_irq(int irq, void *dev_id)
{
struct i2c_client *client = dev_id;
struct m41t80_data *m41t80 = i2c_get_clientdata(client);
- struct mutex *lock = &m41t80->rtc->ops_lock;
unsigned long events = 0;
int flags, flags_afe;
- mutex_lock(lock);
+ rtc_lock(m41t80->rtc);
flags_afe = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
if (flags_afe < 0) {
- mutex_unlock(lock);
+ rtc_unlock(m41t80->rtc);
return IRQ_NONE;
}
flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
if (flags <= 0) {
- mutex_unlock(lock);
+ rtc_unlock(m41t80->rtc);
return IRQ_NONE;
}
@@ -189,7 +189,7 @@ static irqreturn_t m41t80_handle_irq(int irq, void *dev_id)
flags_afe);
}
- mutex_unlock(lock);
+ rtc_unlock(m41t80->rtc);
return IRQ_HANDLED;
}
@@ -205,14 +205,14 @@ static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm)
return flags;
if (flags & M41T80_FLAGS_OF) {
- dev_err(&client->dev, "Oscillator failure, data is invalid.\n");
+ dev_err(&client->dev, "Oscillator failure, time may not be accurate, write time to RTC to fix it.\n");
return -EINVAL;
}
err = i2c_smbus_read_i2c_block_data(client, M41T80_REG_SSEC,
sizeof(buf), buf);
if (err < 0) {
- dev_err(&client->dev, "Unable to read date\n");
+ dev_dbg(&client->dev, "Unable to read date\n");
return err;
}
@@ -228,21 +228,31 @@ static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm)
return 0;
}
-static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm)
+static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *in_tm)
{
struct i2c_client *client = to_i2c_client(dev);
struct m41t80_data *clientdata = i2c_get_clientdata(client);
+ struct rtc_time tm = *in_tm;
unsigned char buf[8];
int err, flags;
+ time64_t time = 0;
+ flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
+ if (flags < 0)
+ return flags;
+ if (flags & M41T80_FLAGS_OF) {
+ /* add 4sec of oscillator stablize time otherwise we are behind 4sec */
+ time = rtc_tm_to_time64(&tm);
+ rtc_time64_to_tm(time + 4, &tm);
+ }
buf[M41T80_REG_SSEC] = 0;
- buf[M41T80_REG_SEC] = bin2bcd(tm->tm_sec);
- buf[M41T80_REG_MIN] = bin2bcd(tm->tm_min);
- buf[M41T80_REG_HOUR] = bin2bcd(tm->tm_hour);
- buf[M41T80_REG_DAY] = bin2bcd(tm->tm_mday);
- buf[M41T80_REG_MON] = bin2bcd(tm->tm_mon + 1);
- buf[M41T80_REG_YEAR] = bin2bcd(tm->tm_year - 100);
- buf[M41T80_REG_WDAY] = tm->tm_wday;
+ buf[M41T80_REG_SEC] = bin2bcd(tm.tm_sec);
+ buf[M41T80_REG_MIN] = bin2bcd(tm.tm_min);
+ buf[M41T80_REG_HOUR] = bin2bcd(tm.tm_hour);
+ buf[M41T80_REG_DAY] = bin2bcd(tm.tm_mday);
+ buf[M41T80_REG_MON] = bin2bcd(tm.tm_mon + 1);
+ buf[M41T80_REG_YEAR] = bin2bcd(tm.tm_year - 100);
+ buf[M41T80_REG_WDAY] = tm.tm_wday;
/* If the square wave output is controlled in the weekday register */
if (clientdata->features & M41T80_FEATURE_SQ_ALT) {
@@ -258,20 +268,37 @@ static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm)
err = i2c_smbus_write_i2c_block_data(client, M41T80_REG_SSEC,
sizeof(buf), buf);
if (err < 0) {
- dev_err(&client->dev, "Unable to write to date registers\n");
+ dev_dbg(&client->dev, "Unable to write to date registers\n");
return err;
}
-
- /* Clear the OF bit of Flags Register */
- flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
- if (flags < 0)
- return flags;
-
- err = i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS,
- flags & ~M41T80_FLAGS_OF);
- if (err < 0) {
- dev_err(&client->dev, "Unable to write flags register\n");
- return err;
+ if (flags & M41T80_FLAGS_OF) {
+ /* OF cannot be immediately reset: oscillator has to be restarted. */
+ dev_warn(&client->dev, "OF bit is still set, kickstarting clock.\n");
+ err = i2c_smbus_write_byte_data(client, M41T80_REG_SEC, M41T80_SEC_ST);
+ if (err < 0) {
+ dev_dbg(&client->dev, "Can't set ST bit\n");
+ return err;
+ }
+ err = i2c_smbus_write_byte_data(client, M41T80_REG_SEC, flags & ~M41T80_SEC_ST);
+ if (err < 0) {
+ dev_dbg(&client->dev, "Can't clear ST bit\n");
+ return err;
+ }
+ /* oscillator must run for 4sec before we attempt to reset OF bit */
+ msleep(4000);
+ /* Clear the OF bit of Flags Register */
+ err = i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS, flags & ~M41T80_FLAGS_OF);
+ if (err < 0) {
+ dev_dbg(&client->dev, "Unable to write flags register\n");
+ return err;
+ }
+ flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS);
+ if (flags < 0) {
+ return flags;
+ } else if (flags & M41T80_FLAGS_OF) {
+ dev_dbg(&client->dev, "Can't clear the OF bit check battery\n");
+ return err;
+ }
}
return err;
@@ -309,7 +336,7 @@ static int m41t80_alarm_irq_enable(struct device *dev, unsigned int enabled)
retval = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, flags);
if (retval < 0) {
- dev_err(dev, "Unable to enable alarm IRQ %d\n", retval);
+ dev_dbg(dev, "Unable to enable alarm IRQ %d\n", retval);
return retval;
}
return 0;
@@ -334,7 +361,7 @@ static int m41t80_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
err = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON,
ret & ~(M41T80_ALMON_AFE));
if (err < 0) {
- dev_err(dev, "Unable to clear AFE bit\n");
+ dev_dbg(dev, "Unable to clear AFE bit\n");
return err;
}
@@ -348,7 +375,7 @@ static int m41t80_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
err = i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS,
ret & ~(M41T80_FLAGS_AF));
if (err < 0) {
- dev_err(dev, "Unable to clear AF bit\n");
+ dev_dbg(dev, "Unable to clear AF bit\n");
return err;
}
@@ -397,10 +424,13 @@ static int m41t80_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
return 0;
}
-static struct rtc_class_ops m41t80_rtc_ops = {
+static const struct rtc_class_ops m41t80_rtc_ops = {
.read_time = m41t80_rtc_read_time,
.set_time = m41t80_rtc_set_time,
.proc = m41t80_rtc_proc,
+ .read_alarm = m41t80_read_alarm,
+ .set_alarm = m41t80_set_alarm,
+ .alarm_irq_enable = m41t80_alarm_irq_enable,
};
#ifdef CONFIG_PM_SLEEP
@@ -454,16 +484,17 @@ static unsigned long m41t80_sqw_recalc_rate(struct clk_hw *hw,
return sqw_to_m41t80_data(hw)->freq;
}
-static long m41t80_sqw_round_rate(struct clk_hw *hw, unsigned long rate,
- unsigned long *prate)
+static int m41t80_sqw_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
{
- if (rate >= M41T80_SQW_MAX_FREQ)
- return M41T80_SQW_MAX_FREQ;
- if (rate >= M41T80_SQW_MAX_FREQ / 4)
- return M41T80_SQW_MAX_FREQ / 4;
- if (!rate)
- return 0;
- return 1 << ilog2(rate);
+ if (req->rate >= M41T80_SQW_MAX_FREQ)
+ req->rate = M41T80_SQW_MAX_FREQ;
+ else if (req->rate >= M41T80_SQW_MAX_FREQ / 4)
+ req->rate = M41T80_SQW_MAX_FREQ / 4;
+ else if (req->rate)
+ req->rate = 1 << ilog2(req->rate);
+
+ return 0;
}
static int m41t80_sqw_set_rate(struct clk_hw *hw, unsigned long rate,
@@ -534,7 +565,7 @@ static const struct clk_ops m41t80_sqw_ops = {
.unprepare = m41t80_sqw_unprepare,
.is_prepared = m41t80_sqw_is_prepared,
.recalc_rate = m41t80_sqw_recalc_rate,
- .round_rate = m41t80_sqw_round_rate,
+ .determine_rate = m41t80_sqw_determine_rate,
.set_rate = m41t80_sqw_set_rate,
};
@@ -542,10 +573,22 @@ static struct clk *m41t80_sqw_register_clk(struct m41t80_data *m41t80)
{
struct i2c_client *client = m41t80->client;
struct device_node *node = client->dev.of_node;
+ struct device_node *fixed_clock;
struct clk *clk;
struct clk_init_data init;
int ret;
+ fixed_clock = of_get_child_by_name(node, "clock");
+ if (fixed_clock) {
+ /*
+ * skip registering square wave clock when a fixed
+ * clock has been registered. The fixed clock is
+ * registered automatically when being referenced.
+ */
+ of_node_put(fixed_clock);
+ return NULL;
+ }
+
/* First disable the clock */
ret = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON);
if (ret < 0)
@@ -597,10 +640,8 @@ static unsigned long wdt_is_open;
static int boot_flag;
/**
- * wdt_ping:
- *
- * Reload counter one with the watchdog timeout. We don't bother reloading
- * the cascade counter.
+ * wdt_ping - Reload counter one with the watchdog timeout.
+ * We don't bother reloading the cascade counter.
*/
static void wdt_ping(void)
{
@@ -636,9 +677,7 @@ static void wdt_ping(void)
}
/**
- * wdt_disable:
- *
- * disables watchdog.
+ * wdt_disable - disables watchdog.
*/
static void wdt_disable(void)
{
@@ -675,14 +714,14 @@ static void wdt_disable(void)
}
/**
- * wdt_write:
+ * wdt_write - write to watchdog.
* @file: file handle to the watchdog
* @buf: buffer to write (unused as data does not matter here
* @count: count of bytes
* @ppos: pointer to the position to write. No seeks allowed
*
* A write to a watchdog device is defined as a keepalive signal. Any
- * write of data will do, as we we don't define content meaning.
+ * write of data will do, as we don't define content meaning.
*/
static ssize_t wdt_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
@@ -701,7 +740,7 @@ static ssize_t wdt_read(struct file *file, char __user *buf,
}
/**
- * wdt_ioctl:
+ * wdt_ioctl - ioctl handler to set watchdog.
* @file: file handle to the device
* @cmd: watchdog command
* @arg: argument pointer
@@ -740,7 +779,7 @@ static int wdt_ioctl(struct file *file, unsigned int cmd,
return -EINVAL;
wdt_margin = new_margin;
wdt_ping();
- /* Fall through */
+ fallthrough;
case WDIOC_GETTIMEOUT:
return put_user(wdt_margin, (int __user *)arg);
@@ -776,14 +815,14 @@ static long wdt_unlocked_ioctl(struct file *file, unsigned int cmd,
}
/**
- * wdt_open:
+ * wdt_open - open a watchdog.
* @inode: inode of device
* @file: file handle to device
*
*/
static int wdt_open(struct inode *inode, struct file *file)
{
- if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
+ if (iminor(inode) == WATCHDOG_MINOR) {
mutex_lock(&m41t80_rtc_mutex);
if (test_and_set_bit(0, &wdt_is_open)) {
mutex_unlock(&m41t80_rtc_mutex);
@@ -800,20 +839,20 @@ static int wdt_open(struct inode *inode, struct file *file)
}
/**
- * wdt_close:
+ * wdt_release - release a watchdog.
* @inode: inode to board
* @file: file handle to board
*
*/
static int wdt_release(struct inode *inode, struct file *file)
{
- if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
+ if (iminor(inode) == WATCHDOG_MINOR)
clear_bit(0, &wdt_is_open);
return 0;
}
/**
- * notify_sys:
+ * wdt_notify_sys - notify to watchdog.
* @this: our notifier block
* @code: the event being reported
* @unused: unused
@@ -840,7 +879,6 @@ static const struct file_operations wdt_fops = {
.write = wdt_write,
.open = wdt_open,
.release = wdt_release,
- .llseek = no_llseek,
};
static struct miscdevice wdt_dev = {
@@ -866,8 +904,7 @@ static struct notifier_block wdt_notifier = {
*****************************************************************************
*/
-static int m41t80_probe(struct i2c_client *client,
- const struct i2c_device_id *id)
+static int m41t80_probe(struct i2c_client *client)
{
struct i2c_adapter *adapter = client->adapter;
int rc = 0;
@@ -887,25 +924,29 @@ static int m41t80_probe(struct i2c_client *client,
return -ENOMEM;
m41t80_data->client = client;
- if (client->dev.of_node)
+ if (client->dev.of_node) {
m41t80_data->features = (unsigned long)
of_device_get_match_data(&client->dev);
- else
+ } else {
+ const struct i2c_device_id *id = i2c_match_id(m41t80_id, client);
m41t80_data->features = id->driver_data;
+ }
i2c_set_clientdata(client, m41t80_data);
m41t80_data->rtc = devm_rtc_allocate_device(&client->dev);
if (IS_ERR(m41t80_data->rtc))
return PTR_ERR(m41t80_data->rtc);
-#ifdef CONFIG_OF
- wakeup_source = of_property_read_bool(client->dev.of_node,
- "wakeup-source");
-#endif
+ wakeup_source = device_property_read_bool(&client->dev, "wakeup-source");
if (client->irq > 0) {
+ unsigned long irqflags = IRQF_TRIGGER_LOW;
+
+ if (dev_fwnode(&client->dev))
+ irqflags = 0;
+
rc = devm_request_threaded_irq(&client->dev, client->irq,
NULL, m41t80_handle_irq,
- IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+ irqflags | IRQF_ONESHOT,
"m41t80", client);
if (rc) {
dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
@@ -913,22 +954,17 @@ static int m41t80_probe(struct i2c_client *client,
wakeup_source = false;
}
}
- if (client->irq > 0 || wakeup_source) {
- m41t80_rtc_ops.read_alarm = m41t80_read_alarm;
- m41t80_rtc_ops.set_alarm = m41t80_set_alarm;
- m41t80_rtc_ops.alarm_irq_enable = m41t80_alarm_irq_enable;
- /* Enable the wakealarm */
+ if (client->irq > 0 || wakeup_source)
device_init_wakeup(&client->dev, true);
- }
+ else
+ clear_bit(RTC_FEATURE_ALARM, m41t80_data->rtc->features);
m41t80_data->rtc->ops = &m41t80_rtc_ops;
m41t80_data->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
m41t80_data->rtc->range_max = RTC_TIMESTAMP_END_2099;
- if (client->irq <= 0) {
- /* We cannot support UIE mode if we do not have an IRQ line */
- m41t80_data->rtc->uie_unsupported = 1;
- }
+ if (client->irq <= 0)
+ clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, m41t80_data->rtc->features);
/* Make sure HT (Halt Update) bit is cleared */
rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR);
@@ -977,14 +1013,14 @@ static int m41t80_probe(struct i2c_client *client,
m41t80_sqw_register_clk(m41t80_data);
#endif
- rc = rtc_register_device(m41t80_data->rtc);
+ rc = devm_rtc_register_device(m41t80_data->rtc);
if (rc)
return rc;
return 0;
}
-static int m41t80_remove(struct i2c_client *client)
+static void m41t80_remove(struct i2c_client *client)
{
#ifdef CONFIG_RTC_DRV_M41T80_WDT
struct m41t80_data *clientdata = i2c_get_clientdata(client);
@@ -994,8 +1030,6 @@ static int m41t80_remove(struct i2c_client *client)
unregister_reboot_notifier(&wdt_notifier);
}
#endif
-
- return 0;
}
static struct i2c_driver m41t80_driver = {
generated by cgit (git 2.34.1) at 2025-12-25 21:42:17 +0000