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authorSteven A. Falco <sfalco@harris.com>2008-10-15 22:03:07 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-16 11:21:40 -0700
commitd3a126fcf9df7dc59f1cc553c2fb2e668264e86c (patch)
tree3e6359d3ad55bc0ecf585eed8ab0361f89889a92 /drivers/rtc/rtc-m41t80.c
parent03274572215a1dfc7c382ef9b18c562612b4d466 (diff)
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rtc: rtc-m41t80.c: add support for the ST M41T65 RTC
Add support for M41T65 Real Time Clock chip. The main differences I see between the M41T65 and M41T80 are that: 1) The M41T65 watchdog timer has three bits controlling resolution (versus two for the M41T80). 2) There is no register 0x13 for controlling square-wave output. Signed-off-by: Steven A. Falco <sfalco@harris.com> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Acked-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/rtc/rtc-m41t80.c')
-rw-r--r--drivers/rtc/rtc-m41t80.c43
1 files changed, 33 insertions, 10 deletions
diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c
index 24bc168..470fb2d 100644
--- a/drivers/rtc/rtc-m41t80.c
+++ b/drivers/rtc/rtc-m41t80.c
@@ -56,21 +56,27 @@
#define M41T80_ALHOUR_HT (1 << 6) /* HT: Halt Update Bit */
#define M41T80_FLAGS_AF (1 << 6) /* AF: Alarm Flag Bit */
#define M41T80_FLAGS_BATT_LOW (1 << 4) /* BL: Battery Low Bit */
+#define M41T80_WATCHDOG_RB2 (1 << 7) /* RB: Watchdog resolution */
+#define M41T80_WATCHDOG_RB1 (1 << 1) /* RB: Watchdog resolution */
+#define M41T80_WATCHDOG_RB0 (1 << 0) /* RB: Watchdog resolution */
-#define M41T80_FEATURE_HT (1 << 0)
-#define M41T80_FEATURE_BL (1 << 1)
+#define M41T80_FEATURE_HT (1 << 0) /* Halt feature */
+#define M41T80_FEATURE_BL (1 << 1) /* Battery low indicator */
+#define M41T80_FEATURE_SQ (1 << 2) /* Squarewave feature */
+#define M41T80_FEATURE_WD (1 << 3) /* Extra watchdog resolution */
#define DRV_VERSION "0.05"
static const struct i2c_device_id m41t80_id[] = {
- { "m41t80", 0 },
- { "m41t81", M41T80_FEATURE_HT },
- { "m41t81s", M41T80_FEATURE_HT | M41T80_FEATURE_BL },
- { "m41t82", M41T80_FEATURE_HT | M41T80_FEATURE_BL },
- { "m41t83", M41T80_FEATURE_HT | M41T80_FEATURE_BL },
- { "m41st84", M41T80_FEATURE_HT | M41T80_FEATURE_BL },
- { "m41st85", M41T80_FEATURE_HT | M41T80_FEATURE_BL },
- { "m41st87", M41T80_FEATURE_HT | M41T80_FEATURE_BL },
+ { "m41t65", M41T80_FEATURE_HT | M41T80_FEATURE_WD },
+ { "m41t80", M41T80_FEATURE_SQ },
+ { "m41t81", M41T80_FEATURE_HT | M41T80_FEATURE_SQ},
+ { "m41t81s", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
+ { "m41t82", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
+ { "m41t83", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
+ { "m41st84", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
+ { "m41st85", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
+ { "m41st87", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ },
{ }
};
MODULE_DEVICE_TABLE(i2c, m41t80_id);
@@ -386,8 +392,12 @@ static ssize_t m41t80_sysfs_show_sqwfreq(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
+ struct m41t80_data *clientdata = i2c_get_clientdata(client);
int val;
+ if (!(clientdata->features & M41T80_FEATURE_SQ))
+ return -EINVAL;
+
val = i2c_smbus_read_byte_data(client, M41T80_REG_SQW);
if (val < 0)
return -EIO;
@@ -408,9 +418,13 @@ static ssize_t m41t80_sysfs_set_sqwfreq(struct device *dev,
const char *buf, size_t count)
{
struct i2c_client *client = to_i2c_client(dev);
+ struct m41t80_data *clientdata = i2c_get_clientdata(client);
int almon, sqw;
int val = simple_strtoul(buf, NULL, 0);
+ if (!(clientdata->features & M41T80_FEATURE_SQ))
+ return -EINVAL;
+
if (val) {
if (!is_power_of_2(val))
return -EINVAL;
@@ -499,6 +513,8 @@ static void wdt_ping(void)
.buf = i2c_data,
},
};
+ struct m41t80_data *clientdata = i2c_get_clientdata(save_client);
+
i2c_data[0] = 0x09; /* watchdog register */
if (wdt_margin > 31)
@@ -509,6 +525,13 @@ static void wdt_ping(void)
*/
i2c_data[1] = wdt_margin<<2 | 0x82;
+ /*
+ * M41T65 has three bits for watchdog resolution. Don't set bit 7, as
+ * that would be an invalid resolution.
+ */
+ if (clientdata->features & M41T80_FEATURE_WD)
+ i2c_data[1] &= ~M41T80_WATCHDOG_RB2;
+
i2c_transfer(save_client->adapter, msgs1, 1);
}