From 8a95b252d194ea57c3d2c16ec2a25b1b70e36cad Mon Sep 17 00:00:00 2001 From: Kumar Gala Date: Mon, 10 Apr 2006 22:54:39 -0700 Subject: [PATCH] RTC subsystem: DS1672 oscillator handling * Always enable the oscillator when we set the time * If the oscillator is disable when we probe the RTC report back a warning to the user * Added sysfs attribute to represent the state of the oscillator Signed-off-by: Kumar Gala Signed-off-by: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-ds1672.c | 61 +++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 58 insertions(+), 3 deletions(-) (limited to 'drivers/rtc/rtc-ds1672.c') diff --git a/drivers/rtc/rtc-ds1672.c b/drivers/rtc/rtc-ds1672.c index 358695a416f..6d2dc706065 100644 --- a/drivers/rtc/rtc-ds1672.c +++ b/drivers/rtc/rtc-ds1672.c @@ -23,6 +23,7 @@ I2C_CLIENT_INSMOD; #define DS1672_REG_CNT_BASE 0 #define DS1672_REG_CONTROL 4 +#define DS1672_REG_CONTROL_EOSC 0x80 #define DS1672_REG_TRICKLE 5 @@ -72,16 +73,17 @@ static int ds1672_get_datetime(struct i2c_client *client, struct rtc_time *tm) static int ds1672_set_mmss(struct i2c_client *client, unsigned long secs) { int xfer; - unsigned char buf[5]; + unsigned char buf[6]; buf[0] = DS1672_REG_CNT_BASE; buf[1] = secs & 0x000000FF; buf[2] = (secs & 0x0000FF00) >> 8; buf[3] = (secs & 0x00FF0000) >> 16; buf[4] = (secs & 0xFF000000) >> 24; + buf[5] = 0; /* set control reg to enable counting */ - xfer = i2c_master_send(client, buf, 5); - if (xfer != 5) { + xfer = i2c_master_send(client, buf, 6); + if (xfer != 6) { dev_err(&client->dev, "%s: send: %d\n", __FUNCTION__, xfer); return -EIO; } @@ -120,6 +122,44 @@ static int ds1672_rtc_set_mmss(struct device *dev, unsigned long secs) return ds1672_set_mmss(to_i2c_client(dev), secs); } +static int ds1672_get_control(struct i2c_client *client, u8 *status) +{ + unsigned char addr = DS1672_REG_CONTROL; + + struct i2c_msg msgs[] = { + { client->addr, 0, 1, &addr }, /* setup read ptr */ + { client->addr, I2C_M_RD, 1, status }, /* read control */ + }; + + /* read control register */ + if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) { + dev_err(&client->dev, "%s: read error\n", __FUNCTION__); + return -EIO; + } + + return 0; +} + +/* following are the sysfs callback functions */ +static ssize_t show_control(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct i2c_client *client = to_i2c_client(dev); + char *state = "enabled"; + u8 control; + int err; + + err = ds1672_get_control(client, &control); + if (err) + return err; + + if (control & DS1672_REG_CONTROL_EOSC) + state = "disabled"; + + return sprintf(buf, "%s\n", state); +} + +static DEVICE_ATTR(control, S_IRUGO, show_control, NULL); + static struct rtc_class_ops ds1672_rtc_ops = { .read_time = ds1672_rtc_read_time, .set_time = ds1672_rtc_set_time, @@ -162,6 +202,7 @@ static struct i2c_driver ds1672_driver = { static int ds1672_probe(struct i2c_adapter *adapter, int address, int kind) { int err = 0; + u8 control; struct i2c_client *client; struct rtc_device *rtc; @@ -202,6 +243,20 @@ static int ds1672_probe(struct i2c_adapter *adapter, int address, int kind) i2c_set_clientdata(client, rtc); + /* read control register */ + err = ds1672_get_control(client, &control); + if (err) { + dev_err(&client->dev, "%s: read error\n", __FUNCTION__); + goto exit_detach; + } + + if (control & DS1672_REG_CONTROL_EOSC) + dev_warn(&client->dev, "Oscillator not enabled. " + "Set time to enable.\n"); + + /* Register sysfs hooks */ + device_create_file(&client->dev, &dev_attr_control); + return 0; exit_detach: -- cgit v1.2.3