rtc-ds1307: alarm support for ds1337/ds1339
Update the ds1307 driver with alarm support for ds1337/ds1339. This uses
the first alarm (there are two), and matches on seconds, minutes, hours,
and day-of-month. Tested on ds1339.
[dbrownell@users.sourceforge.net: add comments; fixup style, valid irq
checks, debug dumps; lock; more careful IRQ shutdown; switch BCD2BIN to
bcd2bin (and vice versa); ENOTTY not EINVAL.]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Rodolfo Giometti <giometti@linux.it>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index bbf97e6..4fcf073 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -23,10 +23,6 @@
* to have set the chip up as a clock (turning on the oscillator and
* setting the date and time), Linux can ignore the non-clock features.
* That's a natural job for a factory or repair bench.
- *
- * This is currently a simple no-alarms driver. If your board has the
- * alarm irq wired up on a ds1337 or ds1339, and you want to use that,
- * then look at the rtc-rs5c372 driver for code to steal...
*/
enum ds_type {
ds_1307,
@@ -67,6 +63,7 @@
# define DS1307_BIT_RS0 0x01
#define DS1337_REG_CONTROL 0x0e
# define DS1337_BIT_nEOSC 0x80
+# define DS1339_BIT_BBSQI 0x20
# define DS1337_BIT_RS2 0x10
# define DS1337_BIT_RS1 0x08
# define DS1337_BIT_INTCN 0x04
@@ -83,19 +80,22 @@
# define DS1337_BIT_OSF 0x80
# define DS1337_BIT_A2I 0x02
# define DS1337_BIT_A1I 0x01
+#define DS1339_REG_ALARM1_SECS 0x07
#define DS1339_REG_TRICKLE 0x10
struct ds1307 {
u8 reg_addr;
- bool has_nvram;
- u8 regs[8];
+ u8 regs[11];
enum ds_type type;
+ unsigned long flags;
+#define HAS_NVRAM 0 /* bit 0 == sysfs file active */
+#define HAS_ALARM 1 /* bit 1 == irq claimed */
struct i2c_msg msg[2];
struct i2c_client *client;
- struct i2c_client dev;
struct rtc_device *rtc;
+ struct work_struct work;
};
struct chip_desc {
@@ -132,12 +132,79 @@
};
MODULE_DEVICE_TABLE(i2c, ds1307_id);
+/*----------------------------------------------------------------------*/
+
+/*
+ * The IRQ logic includes a "real" handler running in IRQ context just
+ * long enough to schedule this workqueue entry. We need a task context
+ * to talk to the RTC, since I2C I/O calls require that; and disable the
+ * IRQ until we clear its status on the chip, so that this handler can
+ * work with any type of triggering (not just falling edge).
+ *
+ * The ds1337 and ds1339 both have two alarms, but we only use the first
+ * one (with a "seconds" field). For ds1337 we expect nINTA is our alarm
+ * signal; ds1339 chips have only one alarm signal.
+ */
+static void ds1307_work(struct work_struct *work)
+{
+ struct ds1307 *ds1307;
+ struct i2c_client *client;
+ struct mutex *lock;
+ int stat, control;
+
+ ds1307 = container_of(work, struct ds1307, work);
+ client = ds1307->client;
+ lock = &ds1307->rtc->ops_lock;
+
+ mutex_lock(lock);
+ stat = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
+ if (stat < 0)
+ goto out;
+
+ if (stat & DS1337_BIT_A1I) {
+ stat &= ~DS1337_BIT_A1I;
+ i2c_smbus_write_byte_data(client, DS1337_REG_STATUS, stat);
+
+ control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
+ if (control < 0)
+ goto out;
+
+ control &= ~DS1337_BIT_A1IE;
+ i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL, control);
+
+ /* rtc_update_irq() assumes that it is called
+ * from IRQ-disabled context.
+ */
+ local_irq_disable();
+ rtc_update_irq(ds1307->rtc, 1, RTC_AF | RTC_IRQF);
+ local_irq_enable();
+ }
+
+out:
+ if (test_bit(HAS_ALARM, &ds1307->flags))
+ enable_irq(client->irq);
+ mutex_unlock(lock);
+}
+
+static irqreturn_t ds1307_irq(int irq, void *dev_id)
+{
+ struct i2c_client *client = dev_id;
+ struct ds1307 *ds1307 = i2c_get_clientdata(client);
+
+ disable_irq_nosync(irq);
+ schedule_work(&ds1307->work);
+ return IRQ_HANDLED;
+}
+
+/*----------------------------------------------------------------------*/
+
static int ds1307_get_time(struct device *dev, struct rtc_time *t)
{
struct ds1307 *ds1307 = dev_get_drvdata(dev);
int tmp;
/* read the RTC date and time registers all at once */
+ ds1307->reg_addr = 0;
ds1307->msg[1].flags = I2C_M_RD;
ds1307->msg[1].len = 7;
@@ -231,9 +298,186 @@
return 0;
}
+static int ds1307_read_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ds1307 *ds1307 = i2c_get_clientdata(client);
+ int ret;
+
+ if (!test_bit(HAS_ALARM, &ds1307->flags))
+ return -EINVAL;
+
+ /* read all ALARM1, ALARM2, and status registers at once */
+ ds1307->reg_addr = DS1339_REG_ALARM1_SECS;
+ ds1307->msg[1].flags = I2C_M_RD;
+ ds1307->msg[1].len = 9;
+
+ ret = i2c_transfer(to_i2c_adapter(client->dev.parent),
+ ds1307->msg, 2);
+ if (ret != 2) {
+ dev_err(dev, "%s error %d\n", "alarm read", ret);
+ return -EIO;
+ }
+
+ dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
+ "alarm read",
+ ds1307->regs[0], ds1307->regs[1],
+ ds1307->regs[2], ds1307->regs[3],
+ ds1307->regs[4], ds1307->regs[5],
+ ds1307->regs[6], ds1307->regs[7],
+ ds1307->regs[8]);
+
+ /* report alarm time (ALARM1); assume 24 hour and day-of-month modes,
+ * and that all four fields are checked matches
+ */
+ t->time.tm_sec = bcd2bin(ds1307->regs[0] & 0x7f);
+ t->time.tm_min = bcd2bin(ds1307->regs[1] & 0x7f);
+ t->time.tm_hour = bcd2bin(ds1307->regs[2] & 0x3f);
+ t->time.tm_mday = bcd2bin(ds1307->regs[3] & 0x3f);
+ t->time.tm_mon = -1;
+ t->time.tm_year = -1;
+ t->time.tm_wday = -1;
+ t->time.tm_yday = -1;
+ t->time.tm_isdst = -1;
+
+ /* ... and status */
+ t->enabled = !!(ds1307->regs[7] & DS1337_BIT_A1IE);
+ t->pending = !!(ds1307->regs[8] & DS1337_BIT_A1I);
+
+ dev_dbg(dev, "%s secs=%d, mins=%d, "
+ "hours=%d, mday=%d, enabled=%d, pending=%d\n",
+ "alarm read", t->time.tm_sec, t->time.tm_min,
+ t->time.tm_hour, t->time.tm_mday,
+ t->enabled, t->pending);
+
+ return 0;
+}
+
+static int ds1307_set_alarm(struct device *dev, struct rtc_wkalrm *t)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ds1307 *ds1307 = i2c_get_clientdata(client);
+ unsigned char *buf = ds1307->regs;
+ u8 control, status;
+ int ret;
+
+ if (!test_bit(HAS_ALARM, &ds1307->flags))
+ return -EINVAL;
+
+ dev_dbg(dev, "%s secs=%d, mins=%d, "
+ "hours=%d, mday=%d, enabled=%d, pending=%d\n",
+ "alarm set", t->time.tm_sec, t->time.tm_min,
+ t->time.tm_hour, t->time.tm_mday,
+ t->enabled, t->pending);
+
+ /* read current status of both alarms and the chip */
+ ds1307->reg_addr = DS1339_REG_ALARM1_SECS;
+ ds1307->msg[1].flags = I2C_M_RD;
+ ds1307->msg[1].len = 9;
+
+ ret = i2c_transfer(to_i2c_adapter(client->dev.parent),
+ ds1307->msg, 2);
+ if (ret != 2) {
+ dev_err(dev, "%s error %d\n", "alarm write", ret);
+ return -EIO;
+ }
+ control = ds1307->regs[7];
+ status = ds1307->regs[8];
+
+ dev_dbg(dev, "%s: %02x %02x %02x %02x, %02x %02x %02x, %02x %02x\n",
+ "alarm set (old status)",
+ ds1307->regs[0], ds1307->regs[1],
+ ds1307->regs[2], ds1307->regs[3],
+ ds1307->regs[4], ds1307->regs[5],
+ ds1307->regs[6], control, status);
+
+ /* set ALARM1, using 24 hour and day-of-month modes */
+ *buf++ = DS1339_REG_ALARM1_SECS; /* first register addr */
+ buf[0] = bin2bcd(t->time.tm_sec);
+ buf[1] = bin2bcd(t->time.tm_min);
+ buf[2] = bin2bcd(t->time.tm_hour);
+ buf[3] = bin2bcd(t->time.tm_mday);
+
+ /* set ALARM2 to non-garbage */
+ buf[4] = 0;
+ buf[5] = 0;
+ buf[6] = 0;
+
+ /* optionally enable ALARM1 */
+ buf[7] = control & ~(DS1337_BIT_A1IE | DS1337_BIT_A2IE);
+ if (t->enabled) {
+ dev_dbg(dev, "alarm IRQ armed\n");
+ buf[7] |= DS1337_BIT_A1IE; /* only ALARM1 is used */
+ }
+ buf[8] = status & ~(DS1337_BIT_A1I | DS1337_BIT_A2I);
+
+ ds1307->msg[1].flags = 0;
+ ds1307->msg[1].len = 10;
+
+ ret = i2c_transfer(to_i2c_adapter(client->dev.parent),
+ &ds1307->msg[1], 1);
+ if (ret != 1) {
+ dev_err(dev, "can't set alarm time\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int ds1307_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct ds1307 *ds1307 = i2c_get_clientdata(client);
+ int ret;
+
+ switch (cmd) {
+ case RTC_AIE_OFF:
+ if (!test_bit(HAS_ALARM, &ds1307->flags))
+ return -ENOTTY;
+
+ ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
+ if (ret < 0)
+ return ret;
+
+ ret &= ~DS1337_BIT_A1IE;
+
+ ret = i2c_smbus_write_byte_data(client,
+ DS1337_REG_CONTROL, ret);
+ if (ret < 0)
+ return ret;
+
+ break;
+
+ case RTC_AIE_ON:
+ if (!test_bit(HAS_ALARM, &ds1307->flags))
+ return -ENOTTY;
+
+ ret = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
+ if (ret < 0)
+ return ret;
+
+ ret |= DS1337_BIT_A1IE;
+
+ ret = i2c_smbus_write_byte_data(client,
+ DS1337_REG_CONTROL, ret);
+ if (ret < 0)
+ return ret;
+
+ break;
+
+ default:
+ return -ENOIOCTLCMD;
+ }
+
+ return 0;
+}
+
static const struct rtc_class_ops ds13xx_rtc_ops = {
.read_time = ds1307_get_time,
.set_time = ds1307_set_time,
+ .read_alarm = ds1307_read_alarm,
+ .set_alarm = ds1307_set_alarm,
+ .ioctl = ds1307_ioctl,
};
/*----------------------------------------------------------------------*/
@@ -327,6 +571,7 @@
int tmp;
const struct chip_desc *chip = &chips[id->driver_data];
struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+ int want_irq = false;
if (!i2c_check_functionality(adapter,
I2C_FUNC_I2C | I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
@@ -353,6 +598,12 @@
switch (ds1307->type) {
case ds_1337:
case ds_1339:
+ /* has IRQ? */
+ if (ds1307->client->irq > 0 && chip->alarm) {
+ INIT_WORK(&ds1307->work, ds1307_work);
+ want_irq = true;
+ }
+
ds1307->reg_addr = DS1337_REG_CONTROL;
ds1307->msg[1].len = 2;
@@ -369,8 +620,20 @@
/* oscillator off? turn it on, so clock can tick. */
if (ds1307->regs[0] & DS1337_BIT_nEOSC)
- i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
- ds1307->regs[0] & ~DS1337_BIT_nEOSC);
+ ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
+
+ /* Using IRQ? Disable the square wave and both alarms.
+ * For ds1339, be sure alarms can trigger when we're
+ * running on Vbackup (BBSQI); we assume ds1337 will
+ * ignore that bit
+ */
+ if (want_irq) {
+ ds1307->regs[0] |= DS1337_BIT_INTCN | DS1339_BIT_BBSQI;
+ ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
+ }
+
+ i2c_smbus_write_byte_data(client, DS1337_REG_CONTROL,
+ ds1307->regs[0]);
/* oscillator fault? clear flag, and warn */
if (ds1307->regs[1] & DS1337_BIT_OSF) {
@@ -495,10 +758,22 @@
goto exit_free;
}
+ if (want_irq) {
+ err = request_irq(client->irq, ds1307_irq, 0,
+ ds1307->rtc->name, client);
+ if (err) {
+ dev_err(&client->dev,
+ "unable to request IRQ!\n");
+ goto exit_irq;
+ }
+ set_bit(HAS_ALARM, &ds1307->flags);
+ dev_dbg(&client->dev, "got IRQ %d\n", client->irq);
+ }
+
if (chip->nvram56) {
err = sysfs_create_bin_file(&client->dev.kobj, &nvram);
if (err == 0) {
- ds1307->has_nvram = true;
+ set_bit(HAS_NVRAM, &ds1307->flags);
dev_info(&client->dev, "56 bytes nvram\n");
}
}
@@ -512,7 +787,9 @@
ds1307->regs[2], ds1307->regs[3],
ds1307->regs[4], ds1307->regs[5],
ds1307->regs[6]);
-
+exit_irq:
+ if (ds1307->rtc)
+ rtc_device_unregister(ds1307->rtc);
exit_free:
kfree(ds1307);
return err;
@@ -520,9 +797,14 @@
static int __devexit ds1307_remove(struct i2c_client *client)
{
- struct ds1307 *ds1307 = i2c_get_clientdata(client);
+ struct ds1307 *ds1307 = i2c_get_clientdata(client);
- if (ds1307->has_nvram)
+ if (test_and_clear_bit(HAS_ALARM, &ds1307->flags)) {
+ free_irq(client->irq, client);
+ cancel_work_sync(&ds1307->work);
+ }
+
+ if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags))
sysfs_remove_bin_file(&client->dev.kobj, &nvram);
rtc_device_unregister(ds1307->rtc);