diff options
Diffstat (limited to 'target/linux/bcm27xx/patches-4.19/950-0786-leds-pca963x-Fix-open-drain-initialization.patch')
| -rw-r--r-- | target/linux/bcm27xx/patches-4.19/950-0786-leds-pca963x-Fix-open-drain-initialization.patch | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-4.19/950-0786-leds-pca963x-Fix-open-drain-initialization.patch b/target/linux/bcm27xx/patches-4.19/950-0786-leds-pca963x-Fix-open-drain-initialization.patch new file mode 100644 index 0000000000..e63d4c6bc1 --- /dev/null +++ b/target/linux/bcm27xx/patches-4.19/950-0786-leds-pca963x-Fix-open-drain-initialization.patch @@ -0,0 +1,61 @@ +From 1738aaf187e0c8e97fbdd9661960b835f45e8985 Mon Sep 17 00:00:00 2001 +From: Zahari Petkov <zahari@balena.io> +Date: Mon, 18 Nov 2019 23:02:55 +0200 +Subject: [PATCH] leds: pca963x: Fix open-drain initialization + +commit 697529091ac7a0a90ca349b914bb30641c13c753 upstream. + +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> +--- + drivers/leds/leds-pca963x.c | 8 +++++--- + 1 file changed, 5 insertions(+), 3 deletions(-) + +--- a/drivers/leds/leds-pca963x.c ++++ b/drivers/leds/leds-pca963x.c +@@ -43,6 +43,8 @@ + #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 +@@ -462,12 +464,12 @@ static int pca963x_probe(struct i2c_clie + PCA963X_MODE2); + /* Configure output: open-drain or totem pole (push-pull) */ + if (pdata->outdrv == PCA963X_OPEN_DRAIN) +- mode2 |= 0x01; ++ mode2 &= ~PCA963X_MODE2_OUTDRV; + else +- 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, + mode2); + } |