diff options
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/Kconfig | 3 | ||||
| -rw-r--r-- | drivers/rtc/rtc-ds3232.c | 181 |
2 files changed, 183 insertions, 1 deletions
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 636ba822488..6a77437d4f5 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -171,7 +171,8 @@ config RTC_DRV_DS3232 depends on RTC_CLASS && I2C help If you say yes here you get support for Dallas Semiconductor - DS3232 real-time clock chips. + DS3232 real-time clock chips. If an interrupt is associated + with the device, the alarm functionality is supported. This driver can also be built as a module. If so, the module will be called rtc-ds3232. diff --git a/drivers/rtc/rtc-ds3232.c b/drivers/rtc/rtc-ds3232.c index 9de8516e353..57063552d3b 100644 --- a/drivers/rtc/rtc-ds3232.c +++ b/drivers/rtc/rtc-ds3232.c @@ -2,6 +2,7 @@ * RTC client/driver for the Maxim/Dallas DS3232 Real-Time Clock over I2C * * Copyright (C) 2009-2010 Freescale Semiconductor. + * Author: Jack Lan <jack.lan@freescale.com> * * 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 @@ -175,6 +176,182 @@ static int ds3232_set_time(struct device *dev, struct rtc_time *time) DS3232_REG_SECONDS, 7, buf); } +/* + * DS3232 has two alarm, we only use alarm1 + * According to linux specification, only support one-shot alarm + * no periodic alarm mode + */ +static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct i2c_client *client = to_i2c_client(dev); + struct ds3232 *ds3232 = i2c_get_clientdata(client); + int control, stat; + int ret; + u8 buf[4]; + + mutex_lock(&ds3232->mutex); + + ret = i2c_smbus_read_byte_data(client, DS3232_REG_SR); + if (ret < 0) + goto out; + stat = ret; + ret = i2c_smbus_read_byte_data(client, DS3232_REG_CR); + if (ret < 0) + goto out; + control = ret; + ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf); + if (ret < 0) + goto out; + + alarm->time.tm_sec = bcd2bin(buf[0] & 0x7F); + alarm->time.tm_min = bcd2bin(buf[1] & 0x7F); + alarm->time.tm_hour = bcd2bin(buf[2] & 0x7F); + alarm->time.tm_mday = bcd2bin(buf[3] & 0x7F); + + alarm->time.tm_mon = -1; + alarm->time.tm_year = -1; + alarm->time.tm_wday = -1; + alarm->time.tm_yday = -1; + alarm->time.tm_isdst = -1; + + alarm->enabled = !!(control & DS3232_REG_CR_A1IE); + alarm->pending = !!(stat & DS3232_REG_SR_A1F); + + ret = 0; +out: + mutex_unlock(&ds3232->mutex); + return ret; +} + +/* + * linux rtc-module does not support wday alarm + * and only 24h time mode supported indeed + */ +static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct i2c_client *client = to_i2c_client(dev); + struct ds3232 *ds3232 = i2c_get_clientdata(client); + int control, stat; + int ret; + u8 buf[4]; + + if (client->irq <= 0) + return -EINVAL; + + mutex_lock(&ds3232->mutex); + + buf[0] = bin2bcd(alarm->time.tm_sec); + buf[1] = bin2bcd(alarm->time.tm_min); + buf[2] = bin2bcd(alarm->time.tm_hour); + buf[3] = bin2bcd(alarm->time.tm_mday); + + /* clear alarm interrupt enable bit */ + ret = i2c_smbus_read_byte_data(client, DS3232_REG_CR); + if (ret < 0) + goto out; + control = ret; + control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE); + ret = i2c_smbus_write_byte_data(client, DS3232_REG_CR, control); + if (ret < 0) + goto out; + + /* clear any pending alarm flag */ + ret = i2c_smbus_read_byte_data(client, DS3232_REG_SR); + if (ret < 0) + goto out; + stat = ret; + stat &= ~(DS3232_REG_SR_A1F | DS3232_REG_SR_A2F); + ret = i2c_smbus_write_byte_data(client, DS3232_REG_SR, stat); + if (ret < 0) + goto out; + + ret = i2c_smbus_write_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf); + + if (alarm->enabled) { + control |= DS3232_REG_CR_A1IE; + ret = i2c_smbus_write_byte_data(client, DS3232_REG_CR, control); + } +out: + mutex_unlock(&ds3232->mutex); + return ret; +} + +static void ds3232_update_alarm(struct i2c_client *client) +{ + struct ds3232 *ds3232 = i2c_get_clientdata(client); + int control; + int ret; + u8 buf[4]; + + mutex_lock(&ds3232->mutex); + + ret = i2c_smbus_read_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf); + if (ret < 0) + goto unlock; + + buf[0] = bcd2bin(buf[0]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ? + 0x80 : buf[0]; + buf[1] = bcd2bin(buf[1]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ? + 0x80 : buf[1]; + buf[2] = bcd2bin(buf[2]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ? + 0x80 : buf[2]; + buf[3] = bcd2bin(buf[3]) < 0 || (ds3232->rtc->irq_data & RTC_UF) ? + 0x80 : buf[3]; + + ret = i2c_smbus_write_i2c_block_data(client, DS3232_REG_ALARM1, 4, buf); + if (ret < 0) + goto unlock; + + control = i2c_smbus_read_byte_data(client, DS3232_REG_CR); + if (control < 0) + goto unlock; + + if (ds3232->rtc->irq_data & (RTC_AF | RTC_UF)) + /* enable alarm1 interrupt */ + control |= DS3232_REG_CR_A1IE; + else + /* disable alarm1 interrupt */ + control &= ~(DS3232_REG_CR_A1IE); + i2c_smbus_write_byte_data(client, DS3232_REG_CR, control); + +unlock: + mutex_unlock(&ds3232->mutex); +} + +static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct i2c_client *client = to_i2c_client(dev); + struct ds3232 *ds3232 = i2c_get_clientdata(client); + + if (client->irq <= 0) + return -EINVAL; + + if (enabled) + ds3232->rtc->irq_data |= RTC_AF; + else + ds3232->rtc->irq_data &= ~RTC_AF; + + ds3232_update_alarm(client); + return 0; +} + +static int ds3232_update_irq_enable(struct device *dev, unsigned int enabled) +{ + struct i2c_client *client = to_i2c_client(dev); + struct ds3232 *ds3232 = i2c_get_clientdata(client); + + if (client->irq <= 0) + return -EINVAL; + + if (enabled) + ds3232->rtc->irq_data |= RTC_UF; + else + ds3232->rtc->irq_data &= ~RTC_UF; + + ds3232_update_alarm(client); + return 0; +} + static irqreturn_t ds3232_irq(int irq, void *dev_id) { struct i2c_client *client = dev_id; @@ -222,6 +399,10 @@ unlock: static const struct rtc_class_ops ds3232_rtc_ops = { .read_time = ds3232_read_time, .set_time = ds3232_set_time, + .read_alarm = ds3232_read_alarm, + .set_alarm = ds3232_set_alarm, + .alarm_irq_enable = ds3232_alarm_irq_enable, + .update_irq_enable = ds3232_update_irq_enable, }; static int __devinit ds3232_probe(struct i2c_client *client, |