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path: root/drivers/rtc/rtc-s35390a.c
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Diffstat (limited to 'drivers/rtc/rtc-s35390a.c')
-rw-r--r--drivers/rtc/rtc-s35390a.c345
1 files changed, 210 insertions, 135 deletions
diff --git a/drivers/rtc/rtc-s35390a.c b/drivers/rtc/rtc-s35390a.c
index f40afdd0e5f5..3408d2ab2741 100644
--- a/drivers/rtc/rtc-s35390a.c
+++ b/drivers/rtc/rtc-s35390a.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Seiko Instruments S-35390A RTC Driver
*
* Copyright (c) 2007 Byron Bradley
- *
- * 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.
*/
#include <linux/module.h>
@@ -15,6 +11,7 @@
#include <linux/bitrev.h>
#include <linux/bcd.h>
#include <linux/slab.h>
+#include <linux/delay.h>
#define S35390A_CMD_STATUS1 0
#define S35390A_CMD_STATUS2 1
@@ -34,28 +31,38 @@
#define S35390A_ALRM_BYTE_HOURS 1
#define S35390A_ALRM_BYTE_MINS 2
-#define S35390A_FLAG_POC 0x01
-#define S35390A_FLAG_BLD 0x02
-#define S35390A_FLAG_24H 0x40
-#define S35390A_FLAG_RESET 0x80
-#define S35390A_FLAG_TEST 0x01
+/* flags for STATUS1 */
+#define S35390A_FLAG_POC BIT(0)
+#define S35390A_FLAG_BLD BIT(1)
+#define S35390A_FLAG_INT2 BIT(2)
+#define S35390A_FLAG_24H BIT(6)
+#define S35390A_FLAG_RESET BIT(7)
-#define S35390A_INT2_MODE_MASK 0xF0
+/* flag for STATUS2 */
+#define S35390A_FLAG_TEST BIT(0)
+/* INT2 pin output mode */
+#define S35390A_INT2_MODE_MASK 0x0E
#define S35390A_INT2_MODE_NOINTR 0x00
-#define S35390A_INT2_MODE_FREQ 0x10
-#define S35390A_INT2_MODE_ALARM 0x40
-#define S35390A_INT2_MODE_PMIN_EDG 0x20
+#define S35390A_INT2_MODE_ALARM BIT(1) /* INT2AE */
+#define S35390A_INT2_MODE_PMIN_EDG BIT(2) /* INT2ME */
+#define S35390A_INT2_MODE_FREQ BIT(3) /* INT2FE */
+#define S35390A_INT2_MODE_PMIN (BIT(3) | BIT(2)) /* INT2FE | INT2ME */
static const struct i2c_device_id s35390a_id[] = {
- { "s35390a", 0 },
+ { "s35390a" },
{ }
};
MODULE_DEVICE_TABLE(i2c, s35390a_id);
+static const __maybe_unused struct of_device_id s35390a_of_match[] = {
+ { .compatible = "sii,s35390a" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, s35390a_of_match);
+
struct s35390a {
struct i2c_client *client[8];
- struct rtc_device *rtc;
int twentyfourhour;
};
@@ -94,19 +101,69 @@ static int s35390a_get_reg(struct s35390a *s35390a, int reg, char *buf, int len)
return 0;
}
-static int s35390a_reset(struct s35390a *s35390a)
+static int s35390a_init(struct s35390a *s35390a)
{
- char buf[1];
-
- if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf)) < 0)
- return -EIO;
+ u8 buf;
+ int ret;
+ unsigned initcount = 0;
+
+ /*
+ * At least one of POC and BLD are set, so reinitialise chip. Keeping
+ * this information in the hardware to know later that the time isn't
+ * valid is unfortunately not possible because POC and BLD are cleared
+ * on read. So the reset is best done now.
+ *
+ * The 24H bit is kept over reset, so set it already here.
+ */
+initialize:
+ buf = S35390A_FLAG_RESET | S35390A_FLAG_24H;
+ ret = s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1);
+
+ if (ret < 0)
+ return ret;
+
+ ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1);
+ if (ret < 0)
+ return ret;
+
+ if (buf & (S35390A_FLAG_POC | S35390A_FLAG_BLD)) {
+ /* Try up to five times to reset the chip */
+ if (initcount < 5) {
+ ++initcount;
+ goto initialize;
+ } else
+ return -EIO;
+ }
- if (!(buf[0] & (S35390A_FLAG_POC | S35390A_FLAG_BLD)))
- return 0;
+ return 1;
+}
- buf[0] |= (S35390A_FLAG_RESET | S35390A_FLAG_24H);
- buf[0] &= 0xf0;
- return s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf));
+/*
+ * Returns <0 on error, 0 if rtc is setup fine and 1 if the chip was reset.
+ * To keep the information if an irq is pending, pass the value read from
+ * STATUS1 to the caller.
+ */
+static int s35390a_read_status(struct s35390a *s35390a, char *status1)
+{
+ int ret;
+
+ ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, status1, 1);
+ if (ret < 0)
+ return ret;
+
+ if (*status1 & S35390A_FLAG_POC) {
+ /*
+ * Do not communicate for 0.5 seconds since the power-on
+ * detection circuit is in operation.
+ */
+ msleep(500);
+ return 1;
+ } else if (*status1 & S35390A_FLAG_BLD)
+ return 1;
+ /*
+ * If both POC and BLD are unset everything is fine.
+ */
+ return 0;
}
static int s35390a_disable_test_mode(struct s35390a *s35390a)
@@ -148,17 +205,21 @@ static int s35390a_reg2hr(struct s35390a *s35390a, char reg)
return hour;
}
-static int s35390a_set_datetime(struct i2c_client *client, struct rtc_time *tm)
+static int s35390a_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
+ struct i2c_client *client = to_i2c_client(dev);
struct s35390a *s35390a = i2c_get_clientdata(client);
- int i, err;
- char buf[7];
+ int i;
+ char buf[7], status;
dev_dbg(&client->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);
+ if (s35390a_read_status(s35390a, &status) == 1)
+ s35390a_init(s35390a);
+
buf[S35390A_BYTE_YEAR] = bin2bcd(tm->tm_year - 100);
buf[S35390A_BYTE_MONTH] = bin2bcd(tm->tm_mon + 1);
buf[S35390A_BYTE_DAY] = bin2bcd(tm->tm_mday);
@@ -171,17 +232,19 @@ static int s35390a_set_datetime(struct i2c_client *client, struct rtc_time *tm)
for (i = 0; i < 7; ++i)
buf[i] = bitrev8(buf[i]);
- err = s35390a_set_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
-
- return err;
+ return s35390a_set_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
}
-static int s35390a_get_datetime(struct i2c_client *client, struct rtc_time *tm)
+static int s35390a_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
+ struct i2c_client *client = to_i2c_client(dev);
struct s35390a *s35390a = i2c_get_clientdata(client);
- char buf[7];
+ char buf[7], status;
int i, err;
+ if (s35390a_read_status(s35390a, &status) == 1)
+ return -EINVAL;
+
err = s35390a_get_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf));
if (err < 0)
return err;
@@ -203,11 +266,12 @@ static int s35390a_get_datetime(struct i2c_client *client, struct rtc_time *tm)
tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year,
tm->tm_wday);
- return rtc_valid_tm(tm);
+ return 0;
}
-static int s35390a_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alm)
+static int s35390a_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
+ struct i2c_client *client = to_i2c_client(dev);
struct s35390a *s35390a = i2c_get_clientdata(client);
char buf[3], sts = 0;
int err, i;
@@ -217,12 +281,12 @@ static int s35390a_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alm)
alm->time.tm_min, alm->time.tm_hour, alm->time.tm_mday,
alm->time.tm_mon, alm->time.tm_year, alm->time.tm_wday);
- /* disable interrupt */
+ /* disable interrupt (which deasserts the irq line) */
err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
if (err < 0)
return err;
- /* clear pending interrupt, if any */
+ /* clear pending interrupt (in STATUS1 only), if any */
err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &sts, sizeof(sts));
if (err < 0)
return err;
@@ -232,9 +296,6 @@ static int s35390a_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alm)
else
sts = S35390A_INT2_MODE_NOINTR;
- /* This chip expects the bits of each byte to be in reverse order */
- sts = bitrev8(sts);
-
/* set interupt mode*/
err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
if (err < 0)
@@ -242,6 +303,8 @@ static int s35390a_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alm)
if (alm->time.tm_wday != -1)
buf[S35390A_ALRM_BYTE_WDAY] = bin2bcd(alm->time.tm_wday) | 0x80;
+ else
+ buf[S35390A_ALRM_BYTE_WDAY] = 0;
buf[S35390A_ALRM_BYTE_HOURS] = s35390a_hr2reg(s35390a,
alm->time.tm_hour) | 0x80;
@@ -259,8 +322,9 @@ static int s35390a_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alm)
return err;
}
-static int s35390a_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alm)
+static int s35390a_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
+ struct i2c_client *client = to_i2c_client(dev);
struct s35390a *s35390a = i2c_get_clientdata(client);
char buf[3], sts;
int i, err;
@@ -269,23 +333,43 @@ static int s35390a_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alm)
if (err < 0)
return err;
- if (bitrev8(sts) != S35390A_INT2_MODE_ALARM)
- return -EINVAL;
+ if ((sts & S35390A_INT2_MODE_MASK) != S35390A_INT2_MODE_ALARM) {
+ /*
+ * When the alarm isn't enabled, the register to configure
+ * the alarm time isn't accessible.
+ */
+ alm->enabled = 0;
+ return 0;
+ } else {
+ alm->enabled = 1;
+ }
err = s35390a_get_reg(s35390a, S35390A_CMD_INT2_REG1, buf, sizeof(buf));
if (err < 0)
return err;
/* This chip returns the bits of each byte in reverse order */
- for (i = 0; i < 3; ++i) {
+ for (i = 0; i < 3; ++i)
buf[i] = bitrev8(buf[i]);
- buf[i] &= ~0x80;
- }
- alm->time.tm_wday = bcd2bin(buf[S35390A_ALRM_BYTE_WDAY]);
- alm->time.tm_hour = s35390a_reg2hr(s35390a,
- buf[S35390A_ALRM_BYTE_HOURS]);
- alm->time.tm_min = bcd2bin(buf[S35390A_ALRM_BYTE_MINS]);
+ /*
+ * B0 of the three matching registers is an enable flag. Iff it is set
+ * the configured value is used for matching.
+ */
+ if (buf[S35390A_ALRM_BYTE_WDAY] & 0x80)
+ alm->time.tm_wday =
+ bcd2bin(buf[S35390A_ALRM_BYTE_WDAY] & ~0x80);
+
+ if (buf[S35390A_ALRM_BYTE_HOURS] & 0x80)
+ alm->time.tm_hour =
+ s35390a_reg2hr(s35390a,
+ buf[S35390A_ALRM_BYTE_HOURS] & ~0x80);
+
+ if (buf[S35390A_ALRM_BYTE_MINS] & 0x80)
+ alm->time.tm_min = bcd2bin(buf[S35390A_ALRM_BYTE_MINS] & ~0x80);
+
+ /* alarm triggers always at s=0 */
+ alm->time.tm_sec = 0;
dev_dbg(&client->dev, "%s: alm is mins=%d, hours=%d, wday=%d\n",
__func__, alm->time.tm_min, alm->time.tm_hour,
@@ -294,24 +378,34 @@ static int s35390a_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alm)
return 0;
}
-static int s35390a_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
-{
- return s35390a_read_alarm(to_i2c_client(dev), alm);
-}
-
-static int s35390a_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
+static int s35390a_rtc_ioctl(struct device *dev, unsigned int cmd,
+ unsigned long arg)
{
- return s35390a_set_alarm(to_i2c_client(dev), alm);
-}
+ struct i2c_client *client = to_i2c_client(dev);
+ struct s35390a *s35390a = i2c_get_clientdata(client);
+ char sts;
+ int err;
-static int s35390a_rtc_read_time(struct device *dev, struct rtc_time *tm)
-{
- return s35390a_get_datetime(to_i2c_client(dev), tm);
-}
+ switch (cmd) {
+ case RTC_VL_READ:
+ /* s35390a_reset set lowvoltage flag and init RTC if needed */
+ err = s35390a_read_status(s35390a, &sts);
+ if (err < 0)
+ return err;
+ if (copy_to_user((void __user *)arg, &err, sizeof(int)))
+ return -EFAULT;
+ break;
+ case RTC_VL_CLR:
+ /* update flag and clear register */
+ err = s35390a_init(s35390a);
+ if (err < 0)
+ return err;
+ break;
+ default:
+ return -ENOIOCTLCMD;
+ }
-static int s35390a_rtc_set_time(struct device *dev, struct rtc_time *tm)
-{
- return s35390a_set_datetime(to_i2c_client(dev), tm);
+ return 0;
}
static const struct rtc_class_ops s35390a_rtc_ops = {
@@ -319,111 +413,92 @@ static const struct rtc_class_ops s35390a_rtc_ops = {
.set_time = s35390a_rtc_set_time,
.set_alarm = s35390a_rtc_set_alarm,
.read_alarm = s35390a_rtc_read_alarm,
-
+ .ioctl = s35390a_rtc_ioctl,
};
-static struct i2c_driver s35390a_driver;
-
-static int s35390a_probe(struct i2c_client *client,
- const struct i2c_device_id *id)
+static int s35390a_probe(struct i2c_client *client)
{
- int err;
+ int err, err_read;
unsigned int i;
struct s35390a *s35390a;
- struct rtc_time tm;
- char buf[1];
+ struct rtc_device *rtc;
+ char buf, status1;
+ struct device *dev = &client->dev;
- if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
- err = -ENODEV;
- goto exit;
- }
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+ return -ENODEV;
- s35390a = devm_kzalloc(&client->dev, sizeof(struct s35390a),
- GFP_KERNEL);
- if (!s35390a) {
- err = -ENOMEM;
- goto exit;
- }
+ s35390a = devm_kzalloc(dev, sizeof(struct s35390a), GFP_KERNEL);
+ if (!s35390a)
+ return -ENOMEM;
s35390a->client[0] = client;
i2c_set_clientdata(client, s35390a);
/* This chip uses multiple addresses, use dummy devices for them */
for (i = 1; i < 8; ++i) {
- s35390a->client[i] = i2c_new_dummy(client->adapter,
- client->addr + i);
- if (!s35390a->client[i]) {
- dev_err(&client->dev, "Address %02x unavailable\n",
- client->addr + i);
- err = -EBUSY;
- goto exit_dummy;
+ s35390a->client[i] = devm_i2c_new_dummy_device(dev,
+ client->adapter,
+ client->addr + i);
+ if (IS_ERR(s35390a->client[i])) {
+ dev_err(dev, "Address %02x unavailable\n",
+ client->addr + i);
+ return PTR_ERR(s35390a->client[i]);
}
}
- err = s35390a_reset(s35390a);
- if (err < 0) {
- dev_err(&client->dev, "error resetting chip\n");
- goto exit_dummy;
- }
+ rtc = devm_rtc_allocate_device(dev);
+ if (IS_ERR(rtc))
+ return PTR_ERR(rtc);
- err = s35390a_disable_test_mode(s35390a);
- if (err < 0) {
- dev_err(&client->dev, "error disabling test mode\n");
- goto exit_dummy;
+ err_read = s35390a_read_status(s35390a, &status1);
+ if (err_read < 0) {
+ dev_err(dev, "error resetting chip\n");
+ return err_read;
}
- err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, buf, sizeof(buf));
- if (err < 0) {
- dev_err(&client->dev, "error checking 12/24 hour mode\n");
- goto exit_dummy;
- }
- if (buf[0] & S35390A_FLAG_24H)
+ if (status1 & S35390A_FLAG_24H)
s35390a->twentyfourhour = 1;
else
s35390a->twentyfourhour = 0;
- if (s35390a_get_datetime(client, &tm) < 0)
- dev_warn(&client->dev, "clock needs to be set\n");
-
- device_set_wakeup_capable(&client->dev, 1);
-
- s35390a->rtc = devm_rtc_device_register(&client->dev,
- s35390a_driver.driver.name,
- &s35390a_rtc_ops, THIS_MODULE);
-
- if (IS_ERR(s35390a->rtc)) {
- err = PTR_ERR(s35390a->rtc);
- goto exit_dummy;
+ if (status1 & S35390A_FLAG_INT2) {
+ /* disable alarm (and maybe test mode) */
+ buf = 0;
+ err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &buf, 1);
+ if (err < 0) {
+ dev_err(dev, "error disabling alarm");
+ return err;
+ }
+ } else {
+ err = s35390a_disable_test_mode(s35390a);
+ if (err < 0) {
+ dev_err(dev, "error disabling test mode\n");
+ return err;
+ }
}
- return 0;
-exit_dummy:
- for (i = 1; i < 8; ++i)
- if (s35390a->client[i])
- i2c_unregister_device(s35390a->client[i]);
+ device_set_wakeup_capable(dev, 1);
-exit:
- return err;
-}
+ rtc->ops = &s35390a_rtc_ops;
+ rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+ rtc->range_max = RTC_TIMESTAMP_END_2099;
-static int s35390a_remove(struct i2c_client *client)
-{
- unsigned int i;
- struct s35390a *s35390a = i2c_get_clientdata(client);
+ set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->features);
+ clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
- for (i = 1; i < 8; ++i)
- if (s35390a->client[i])
- i2c_unregister_device(s35390a->client[i]);
+ if (status1 & S35390A_FLAG_INT2)
+ rtc_update_irq(rtc, 1, RTC_AF);
- return 0;
+ return devm_rtc_register_device(rtc);
}
static struct i2c_driver s35390a_driver = {
.driver = {
.name = "rtc-s35390a",
+ .of_match_table = of_match_ptr(s35390a_of_match),
},
.probe = s35390a_probe,
- .remove = s35390a_remove,
.id_table = s35390a_id,
};
generated by cgit (git 2.34.1) at 2025-12-25 06:53:58 +0000