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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>
hifive-unleashed-5.1
Rodolfo Giometti 2008-10-15 22:02:58 -07:00 committed by Linus Torvalds
parent 2f9b75e09e
commit cb49a5e9ee
1 changed files with 295 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

308
drivers/rtc/rtc-ds1307.c
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@ -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 @@ enum ds_type {
# 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 @@ enum ds_type {
# 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 @@ static const struct i2c_device_id ds1307_id[] = {
};
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 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t)
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 @@ static int __devinit ds1307_probe(struct i2c_client *client,
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 @@ static int __devinit ds1307_probe(struct i2c_client *client,
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 @@ static int __devinit ds1307_probe(struct i2c_client *client,
/* 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 @@ read_rtc:
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 @@ exit_bad:
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 @@ exit_free:
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);