diff options
| author | Samu Onkalo <samu.p.onkalo@nokia.com> | 2010-11-24 12:57:04 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-11-25 06:50:43 +0900 |
| commit | 2e4840edb7c485211993919a6a50d93c108198b8 (patch) | |
| tree | 018af5ec842fade7064f1fd00bc9c2186e6037a7 /drivers | |
| parent | 09c76b0f6e8fcd78f2d194acb1f07e41789cc29b (diff) | |
| download | linux-2e4840edb7c485211993919a6a50d93c108198b8.tar.gz linux-2e4840edb7c485211993919a6a50d93c108198b8.tar.bz2 linux-2e4840edb7c485211993919a6a50d93c108198b8.zip | |
drivers/leds/leds-lp5523.c: adjust delays and add comments to them
Delays were little bit too long. Adjust delay times and add some comments
to them.
Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/leds/leds-lp5523.c | 31 |
1 files changed, 17 insertions, 14 deletions
diff --git a/drivers/leds/leds-lp5523.c b/drivers/leds/leds-lp5523.c index 053e1f8b6c0b..4248d78cec37 100644 --- a/drivers/leds/leds-lp5523.c +++ b/drivers/leds/leds-lp5523.c @@ -205,11 +205,14 @@ static int lp5523_configure(struct i2c_client *client) lp5523_write(client, LP5523_REG_RESET, 0xff); - usleep_range(10000, 100000); + usleep_range(10000, 20000); /* + * Exact value is not available. 10 - 20ms + * appears to be enough for reset. + */ ret |= lp5523_write(client, LP5523_REG_ENABLE, LP5523_ENABLE); - /* Chip startup time after reset is 500 us */ - usleep_range(1000, 10000); + /* Chip startup time is 500 us, 1 - 2 ms gives some margin */ + usleep_range(1000, 2000); ret |= lp5523_write(client, LP5523_REG_CONFIG, LP5523_AUTO_INC | LP5523_PWR_SAVE | @@ -246,8 +249,8 @@ static int lp5523_configure(struct i2c_client *client) return -1; } - /* Wait 3ms and check the engine status */ - usleep_range(3000, 20000); + /* Let the programs run for couple of ms and check the engine status */ + usleep_range(3000, 6000); lp5523_read(client, LP5523_REG_STATUS, &status); status &= LP5523_ENG_STATUS_MASK; @@ -452,10 +455,10 @@ static ssize_t lp5523_selftest(struct device *dev, /* Measure VDD (i.e. VBAT) first (channel 16 corresponds to VDD) */ lp5523_write(chip->client, LP5523_REG_LED_TEST_CTRL, LP5523_EN_LEDTEST | 16); - usleep_range(3000, 10000); + usleep_range(3000, 6000); /* ADC conversion time is typically 2.7 ms */ ret = lp5523_read(chip->client, LP5523_REG_STATUS, &status); if (!(status & LP5523_LEDTEST_DONE)) - usleep_range(3000, 10000); + usleep_range(3000, 6000); /* Was not ready. Wait little bit */ ret |= lp5523_read(chip->client, LP5523_REG_LED_TEST_ADC, &vdd); vdd--; /* There may be some fluctuation in measurement */ @@ -471,16 +474,16 @@ static ssize_t lp5523_selftest(struct device *dev, chip->pdata->led_config[i].led_current); lp5523_write(chip->client, LP5523_REG_LED_PWM_BASE + i, 0xff); - /* let current stabilize 2ms before measurements start */ - usleep_range(2000, 10000); + /* let current stabilize 2 - 4ms before measurements start */ + usleep_range(2000, 4000); lp5523_write(chip->client, LP5523_REG_LED_TEST_CTRL, LP5523_EN_LEDTEST | i); - /* ledtest takes 2.7ms */ - usleep_range(3000, 10000); + /* ADC conversion time is 2.7 ms typically */ + usleep_range(3000, 6000); ret = lp5523_read(chip->client, LP5523_REG_STATUS, &status); if (!(status & LP5523_LEDTEST_DONE)) - usleep_range(3000, 10000); + usleep_range(3000, 6000);/* Was not ready. Wait. */ ret |= lp5523_read(chip->client, LP5523_REG_LED_TEST_ADC, &adc); if (adc >= vdd || adc < LP5523_ADC_SHORTCIRC_LIM) @@ -933,9 +936,9 @@ static int lp5523_probe(struct i2c_client *client, if (pdata->enable) { pdata->enable(0); - usleep_range(1000, 10000); + usleep_range(1000, 2000); /* Keep enable down at least 1ms */ pdata->enable(1); - usleep_range(1000, 10000); /* Spec says min 500us */ + usleep_range(1000, 2000); /* 500us abs min. */ } ret = lp5523_detect(client); |