diff options
| author | Jan Kardell <jan.kardell@telliq.com> | 2014-12-10 15:53:43 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-10 17:41:15 -0800 |
| commit | ff0bc5013aca55004034bb366232f8d2b5c6763c (patch) | |
| tree | 66ffa3fe950d17d794aac23280d3d015cb65ad00 /drivers/rtc/rtc-pcf8563.c | |
| parent | 599cda555c1bf6ba9b98e28f707f7b27c8276796 (diff) | |
| download | lwn-ff0bc5013aca55004034bb366232f8d2b5c6763c.tar.gz lwn-ff0bc5013aca55004034bb366232f8d2b5c6763c.zip | |
rtc: pcf8563: save battery power
According to Haoyu hym8563 datasheet this saves som power. Might be
importat to battery life. And maybe it works for the NXP part as well.
Signed-off-by: Jan Kardell <jan.kardell@telliq.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Vincent Donnefort <vdonnefort@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/rtc/rtc-pcf8563.c')
| -rw-r--r-- | drivers/rtc/rtc-pcf8563.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-pcf8563.c b/drivers/rtc/rtc-pcf8563.c index ce6a11bc0fd7..1e14f609db34 100644 --- a/drivers/rtc/rtc-pcf8563.c +++ b/drivers/rtc/rtc-pcf8563.c @@ -42,6 +42,13 @@ #define PCF8563_REG_CLKO 0x0D /* clock out */ #define PCF8563_REG_TMRC 0x0E /* timer control */ +#define PCF8563_TMRC_ENABLE BIT(7) +#define PCF8563_TMRC_4096 0 +#define PCF8563_TMRC_64 1 +#define PCF8563_TMRC_1 2 +#define PCF8563_TMRC_1_60 3 +#define PCF8563_TMRC_MASK 3 + #define PCF8563_REG_TMR 0x0F /* timer */ #define PCF8563_SC_LV 0x80 /* low voltage */ @@ -406,6 +413,7 @@ static int pcf8563_probe(struct i2c_client *client, { struct pcf8563 *pcf8563; int err; + unsigned char buf; dev_dbg(&client->dev, "%s\n", __func__); @@ -423,6 +431,14 @@ static int pcf8563_probe(struct i2c_client *client, pcf8563->client = client; device_set_wakeup_capable(&client->dev, 1); + /* Set timer to lowest frequency to save power (ref Haoyu datasheet) */ + buf = PCF8563_TMRC_1_60; + err = pcf8563_write_block_data(client, PCF8563_REG_TMRC, 1, &buf); + if (err < 0) { + dev_err(&client->dev, "%s: write error\n", __func__); + return err; + } + pcf8563->rtc = devm_rtc_device_register(&client->dev, pcf8563_driver.driver.name, &pcf8563_rtc_ops, THIS_MODULE); |