From 9448217403462c4b17bc56690a0348a0c02e5ba2 Mon Sep 17 00:00:00 2001 From: "Milo(Woogyom) Kim" Date: Tue, 5 Feb 2013 18:03:55 +0900 Subject: [PATCH] leds-lp5521: clean up lp5521_configure() This patch is a preceding step for making common lp55xx init function. LP5521_REG_R_CURRENT register code moved: Chip specific code moved from lp5521_init_device() to lp5521_configure(). Remove engine init function: LP5521 has internal program engines which are used for running LED patterns. (blinking, ramp up/down and other emotional visual effects) Engine initialization is done by reset command in lp5521_init_device(). Remove this duplicate code. Return code: Do not use 'OR' arithmetic for the result. If some error occus, just return it. Enable latency: Use explicit named function, lp5521_wait_enable_done(). According to the datasheet, 500us is guaranteed time. Thus wait time is changed from 1000us to 500us. Signed-off-by: Milo(Woogyom) Kim Signed-off-by: Bryan Wu --- drivers/leds/leds-lp5521.c | 78 ++++++++++++++++++++++------------------------ 1 file changed, 38 insertions(+), 40 deletions(-) diff --git a/drivers/leds/leds-lp5521.c b/drivers/leds/leds-lp5521.c index 1eab155..341a410 100644 --- a/drivers/leds/leds-lp5521.c +++ b/drivers/leds/leds-lp5521.c @@ -125,6 +125,12 @@ struct lp5521_chip { u8 num_leds; }; +static inline void lp5521_wait_enable_done(void) +{ + /* it takes more 488 us to update ENABLE register */ + usleep_range(500, 600); +} + static inline struct lp5521_led *cdev_to_led(struct led_classdev *cdev) { return container_of(cdev, struct lp5521_led, cdev); @@ -229,43 +235,56 @@ static int lp5521_set_led_current(struct lp5521_chip *chip, int led, u8 curr) curr); } -static void lp5521_init_engine(struct lp5521_chip *chip) -{ - int i; - for (i = 0; i < ARRAY_SIZE(chip->engines); i++) { - chip->engines[i].id = i + 1; - chip->engines[i].engine_mask = LP5521_ENG_MASK_BASE >> (i * 2); - chip->engines[i].prog_page = i; - } -} - static int lp5521_configure(struct i2c_client *client) { struct lp5521_chip *chip = i2c_get_clientdata(client); int ret; u8 cfg; + u8 val; - lp5521_init_engine(chip); + /* + * 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! + */ + ret = lp5521_read(client, LP5521_REG_R_CURRENT, &val); + if (ret) { + dev_err(&client->dev, "error in resetting chip\n"); + return ret; + } + if (val != LP5521_REG_R_CURR_DEFAULT) { + dev_err(&client->dev, + "unexpected data in register (expected 0x%x got 0x%x)\n", + LP5521_REG_R_CURR_DEFAULT, val); + ret = -EINVAL; + return ret; + } + usleep_range(10000, 20000); /* Set all PWMs to direct control mode */ ret = lp5521_write(client, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT); cfg = chip->pdata->update_config ? : (LP5521_PWRSAVE_EN | LP5521_CP_MODE_AUTO | LP5521_R_TO_BATT); - ret |= lp5521_write(client, LP5521_REG_CONFIG, cfg); + ret = lp5521_write(client, LP5521_REG_CONFIG, cfg); + if (ret) + return ret; /* Initialize all channels PWM to zero -> leds off */ - ret |= lp5521_write(client, LP5521_REG_R_PWM, 0); - ret |= lp5521_write(client, LP5521_REG_G_PWM, 0); - ret |= lp5521_write(client, LP5521_REG_B_PWM, 0); + lp5521_write(client, LP5521_REG_R_PWM, 0); + lp5521_write(client, LP5521_REG_G_PWM, 0); + lp5521_write(client, LP5521_REG_B_PWM, 0); /* Set engines are set to run state when OP_MODE enables engines */ - ret |= lp5521_write(client, LP5521_REG_ENABLE, + ret = lp5521_write(client, LP5521_REG_ENABLE, LP5521_ENABLE_RUN_PROGRAM); - /* enable takes 500us. 1 - 2 ms leaves some margin */ - usleep_range(1000, 2000); + if (ret) + return ret; - return ret; + lp5521_wait_enable_done(); + + return 0; } static int lp5521_run_selftest(struct lp5521_chip *chip, char *buf) @@ -703,7 +722,6 @@ static int lp5521_init_device(struct lp5521_chip *chip) struct lp5521_platform_data *pdata = chip->pdata; struct i2c_client *client = chip->client; int ret; - u8 buf; if (pdata->setup_resources) { ret = pdata->setup_resources(); @@ -725,26 +743,6 @@ static int lp5521_init_device(struct lp5521_chip *chip) * 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! - */ - ret = lp5521_read(client, LP5521_REG_R_CURRENT, &buf); - if (ret) { - dev_err(&client->dev, "error in resetting chip\n"); - return ret; - } - if (buf != LP5521_REG_R_CURR_DEFAULT) { - dev_err(&client->dev, - "unexpected data in register (expected 0x%x got 0x%x)\n", - LP5521_REG_R_CURR_DEFAULT, buf); - ret = -EINVAL; - return ret; - } - usleep_range(10000, 20000); - ret = lp5521_detect(client); if (ret) { dev_err(&client->dev, "Chip not found\n"); -- 2.7.4