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authorMilo(Woogyom) Kim <milo.kim@ti.com>2013-02-05 13:03:55 +0400
committerBryan Wu <cooloney@gmail.com>2013-02-07 03:59:26 +0400
commit9448217403462c4b17bc56690a0348a0c02e5ba2 (patch)
tree016f181f9e0a83d318600fde32eb33f1f0d6407e /drivers/leds/leds-lp5521.c
parent6a0c9a47963cc72c68713923ead60d1e72e7136c (diff)
downloadlinux-9448217403462c4b17bc56690a0348a0c02e5ba2.tar.xz
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>
Diffstat (limited to 'drivers/leds/leds-lp5521.c')
-rw-r--r--drivers/leds/leds-lp5521.c78
1 files changed, 38 insertions, 40 deletions
diff --git a/drivers/leds/leds-lp5521.c b/drivers/leds/leds-lp5521.c
index 1eab1557a612..341a41030fd8 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");