[PATCH] i2c: Extend ds1337 initialization
Add code to handle case where board firmware does not start the
RTC.
Signed-off-by: Jean Delvare <khali at linux-fr.org>
CC: James Chapman <jchapman at katalix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at suse.de>
---
commit f9e8957937ebf60d22732a5ca9130f48a7603f60
tree c36adb2b1c9e3ef69bf598ee3084966ef7085596
parent 2e3e13f8e9d9b2111404cdccaa4e1b988b70acce
author Michael Burian <dynmail1 at gassner-waagen.at> Mon, 07 Nov 2005 22:30:14 +0100
committer Greg Kroah-Hartman <gregkh at suse.de> Thu, 05 Jan 2006 22:16:20 -0800
drivers/i2c/chips/ds1337.c | 37 +++++++++++++++++++++++++++++++------
1 files changed, 31 insertions(+), 6 deletions(-)
diff --git a/drivers/i2c/chips/ds1337.c b/drivers/i2c/chips/ds1337.c
index 02682fb..1822895 100644
--- a/drivers/i2c/chips/ds1337.c
+++ b/drivers/i2c/chips/ds1337.c
@@ -337,13 +337,38 @@ exit:
static void ds1337_init_client(struct i2c_client *client)
{
- s32 val;
+ u8 status, control;
- /* Ensure that device is set in 24-hour mode */
- val = i2c_smbus_read_byte_data(client, DS1337_REG_HOUR);
- if ((val >= 0) && (val & (1 << 6)))
- i2c_smbus_write_byte_data(client, DS1337_REG_HOUR,
- val & 0x3f);
+ /* On some boards, the RTC isn't configured by boot firmware.
+ * Handle that case by starting/configuring the RTC now.
+ */
+ status = i2c_smbus_read_byte_data(client, DS1337_REG_STATUS);
+ control = i2c_smbus_read_byte_data(client, DS1337_REG_CONTROL);
+
+ if ((status & 0x80) || (control & 0x80)) {
+ /* RTC not running */
+ u8 buf[16];
+ struct i2c_msg msg[1];
+
+ dev_dbg(&client->dev, "%s: RTC not running!\n", __FUNCTION__);
+
+ /* Initialize all, including STATUS and CONTROL to zero */
+ memset(buf, 0, sizeof(buf));
+ msg[0].addr = client->addr;
+ msg[0].flags = 0;
+ msg[0].len = sizeof(buf);
+ msg[0].buf = &buf[0];
+
+ i2c_transfer(client->adapter, msg, 1);
+ } else {
+ /* Running: ensure that device is set in 24-hour mode */
+ s32 val;
+
+ val = i2c_smbus_read_byte_data(client, DS1337_REG_HOUR);
+ if ((val >= 0) && (val & (1 << 6)))
+ i2c_smbus_write_byte_data(client, DS1337_REG_HOUR,
+ val & 0x3f);
+ }
}
static int ds1337_detach_client(struct i2c_client *client)
