diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/leds/leds-lp5521.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/leds/leds-lp5521.c b/drivers/leds/leds-lp5521.c index 16f281b8c2d0..cb641f1b3342 100644 --- a/drivers/leds/leds-lp5521.c +++ b/drivers/leds/leds-lp5521.c @@ -97,6 +97,9 @@ /* Status */ #define LP5521_EXT_CLK_USED 0x08 +/* default R channel current register value */ +#define LP5521_REG_R_CURR_DEFAULT 0xAF + struct lp5521_engine { int id; u8 mode; @@ -643,6 +646,7 @@ static int __devinit lp5521_probe(struct i2c_client *client, struct lp5521_chip *chip; struct lp5521_platform_data *pdata; int ret, i, led; + u8 buf; chip = kzalloc(sizeof(*chip), GFP_KERNEL); if (!chip) @@ -681,6 +685,20 @@ static int __devinit lp5521_probe(struct i2c_client *client, * Exact value is not available. 10 - 20ms * appears to be enough for reset. */ + + /* + * Make sure that the chip is reset by reading back the r channel + * current reg. This is dummy read is required on some platforms - + * otherwise further access to the R G B channels in the + * LP5521_REG_ENABLE register will not have any effect - strange! + */ + lp5521_read(client, LP5521_REG_R_CURRENT, &buf); + if (buf != LP5521_REG_R_CURR_DEFAULT) { + dev_err(&client->dev, "error in reseting chip\n"); + goto fail2; + } + usleep_range(10000, 20000); + ret = lp5521_detect(client); if (ret) { |