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 <milo.kim@ti.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

diff --git a/drivers/leds/leds-lp5521.c b/drivers/leds/leds-lp5521.c
index 1eab155..341a410 100644 (file)
--- 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");