[PATCH 01/10] RTC subsystem, DS1672 oscillator handling

From: Alessandro Zummo
Date: Fri Mar 31 2006 - 05:05:29 EST


From: Kumar Gala <galak@xxxxxxxxxxxxxxxxxxx>

* 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@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Alessandro Zummo <a.zummo@xxxxxxxxxxxx>

---
commit 3acc1a4629e70bce7493b5463f3c785379ae8b6b
tree 34463406603ac788697d8d228a2caf2c0ea40b3a
parent 329b10bb0feacb7fb9a41389313ff0a51ae56f2a
author Kumar Gala <galak@xxxxxxxxxxxxxxxxxxx> Tue, 28 Mar 2006 16:53:43 -0600
committer Kumar Gala <galak@xxxxxxxxxxxxxxxxxxx> Tue, 28 Mar 2006 16:53:43 -0600

drivers/rtc/rtc-ds1672.c | 61 ++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 58 insertions(+), 3 deletions(-)

--- linux-rtc.orig/drivers/rtc/rtc-ds1672.c 2006-03-29 02:14:50.000000000 +0200
+++ linux-rtc/drivers/rtc/rtc-ds1672.c 2006-03-29 02:16:01.000000000 +0200
@@ -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 i2
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 de
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_adapt

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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