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authorKumar Gala <galak@kernel.crashing.org>2006-04-10 22:54:39 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-04-11 06:18:46 -0700
commit8a95b252d194ea57c3d2c16ec2a25b1b70e36cad (patch)
tree6e1b3ca9cbb913905f6065545aed06574dfd6967 /drivers/rtc
parent389ed39b9711bbe5210d5e118e1f1af36ca88b7c (diff)
downloadlwn-8a95b252d194ea57c3d2c16ec2a25b1b70e36cad.tar.gz
lwn-8a95b252d194ea57c3d2c16ec2a25b1b70e36cad.zip
[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 <galak@kernel.crashing.org> Signed-off-by: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/rtc')
-rw-r--r--drivers/rtc/rtc-ds1672.c61
1 files changed, 58 insertions, 3 deletions
diff --git a/drivers/rtc/rtc-ds1672.c b/drivers/rtc/rtc-ds1672.c
index 358695a416f3..6d2dc7060652 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: