Commit 8a95b252 authored by Kumar Gala's avatar Kumar Gala Committed by Linus Torvalds
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[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: default avatarKumar Gala <galak@kernel.crashing.org>
Signed-off-by: default avatarAlessandro Zummo <a.zummo@towertech.it>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 389ed39b
......@@ -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:
......
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