diff options
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-ds1307.c | 308 |
1 files changed, 295 insertions, 13 deletions
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c index bbf97e65202a..4fcf0734a6ef 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 @@ 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 (test_and_clear_bit(HAS_ALARM, &ds1307->flags)) { + free_irq(client->irq, client); + cancel_work_sync(&ds1307->work); + } - if (ds1307->has_nvram) + if (test_and_clear_bit(HAS_NVRAM, &ds1307->flags)) sysfs_remove_bin_file(&client->dev.kobj, &nvram); rtc_device_unregister(ds1307->rtc); |