path: root/drivers
diff options
authorZahari Petkov <zahari@balena.io>2019-11-18 23:02:55 +0200
committerPavel <pavel@ucw.cz>2019-12-21 20:09:51 +0100
commit697529091ac7a0a90ca349b914bb30641c13c753 (patch)
tree20f800a6e25b36a5c9890f11c5e5f1ce5e041d4b /drivers
parentleds-as3645a: Drop fwnode reference on ignored node (diff)
leds: pca963x: Fix open-drain initialization
Before commit bb29b9cccd95 ("leds: pca963x: Add bindings to invert polarity") Mode register 2 was initialized directly with either 0x01 or 0x05 for open-drain or totem pole (push-pull) configuration. Afterwards, MODE2 initialization started using bitwise operations on top of the default MODE2 register value (0x05). Using bitwise OR for setting OUTDRV with 0x01 and 0x05 does not produce correct results. When open-drain is used, instead of setting OUTDRV to 0, the driver keeps it as 1: Open-drain: 0x05 | 0x01 -> 0x05 (0b101 - incorrect) Totem pole: 0x05 | 0x05 -> 0x05 (0b101 - correct but still wrong) Now OUTDRV setting uses correct bitwise operations for initialization: Open-drain: 0x05 & ~0x04 -> 0x01 (0b001 - correct) Totem pole: 0x05 | 0x04 -> 0x05 (0b101 - correct) Additional MODE2 register definitions are introduced now as well. Fixes: bb29b9cccd95 ("leds: pca963x: Add bindings to invert polarity") Signed-off-by: Zahari Petkov <zahari@balena.io> Signed-off-by: Pavel Machek <pavel@ucw.cz>
Diffstat (limited to 'drivers')
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/leds/leds-pca963x.c b/drivers/leds/leds-pca963x.c
index 4afc317901a8..66cdc003b8f4 100644
--- a/drivers/leds/leds-pca963x.c
+++ b/drivers/leds/leds-pca963x.c
@@ -40,6 +40,8 @@
#define PCA963X_LED_PWM 0x2 /* Controlled through PWM */
#define PCA963X_LED_GRP_PWM 0x3 /* Controlled through PWM/GRPPWM */
+#define PCA963X_MODE2_OUTDRV 0x04 /* Open-drain or totem pole */
+#define PCA963X_MODE2_INVRT 0x10 /* Normal or inverted direction */
#define PCA963X_MODE2_DMBLNK 0x20 /* Enable blinking */
#define PCA963X_MODE1 0x00
@@ -438,12 +440,12 @@ static int pca963x_probe(struct i2c_client *client,
/* Configure output: open-drain or totem pole (push-pull) */
if (pdata->outdrv == PCA963X_OPEN_DRAIN)
- mode2 |= 0x01;
+ mode2 &= ~PCA963X_MODE2_OUTDRV;
- mode2 |= 0x05;
+ mode2 |= PCA963X_MODE2_OUTDRV;
/* Configure direction: normal or inverted */
if (pdata->dir == PCA963X_INVERTED)
- mode2 |= 0x10;
+ mode2 |= PCA963X_MODE2_INVRT;
i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,