diff options
| author | Michael Burian <dynmail1@gassner-waagen.at> | 2005-11-07 22:30:14 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2006-01-05 22:16:20 -0800 |
| commit | f9e8957937ebf60d22732a5ca9130f48a7603f60 (patch) | |
| tree | c36adb2b1c9e3ef69bf598ee3084966ef7085596 | |
| parent | 2e3e13f8e9d9b2111404cdccaa4e1b988b70acce (diff) | |
[PATCH] i2c: Extend ds1337 initialization
Add code to handle case where board firmware does not start the
RTC.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
CC: James Chapman <jchapman@katalix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | 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 02682fb794c..18228957606 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) |