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path: root/drivers/leds/leds-lp5521.c
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Diffstat (limited to 'drivers/leds/leds-lp5521.c')
-rw-r--r--drivers/leds/leds-lp5521.c24
1 files changed, 21 insertions, 3 deletions
diff --git a/drivers/leds/leds-lp5521.c b/drivers/leds/leds-lp5521.c
index 9fc122c81f06..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;
@@ -175,14 +178,14 @@ static int lp5521_set_engine_mode(struct lp5521_engine *engine, u8 mode)
mode = LP5521_CMD_DIRECT;
ret = lp5521_read(client, LP5521_REG_OP_MODE, &engine_state);
+ if (ret < 0)
+ return ret;
/* set mode only for this engine */
engine_state &= ~(engine->engine_mask);
mode &= engine->engine_mask;
engine_state |= mode;
- ret |= lp5521_write(client, LP5521_REG_OP_MODE, engine_state);
-
- return ret;
+ return lp5521_write(client, LP5521_REG_OP_MODE, engine_state);
}
static int lp5521_load_program(struct lp5521_engine *eng, const u8 *pattern)
@@ -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) {