From: MarshallZhan-wiwynn <marshall_zhan@xxxxxxxxxx>
The CAT9532 chips are almost 100% compatible with PCA9552, except that
the CAT9532 uses the opposite polarity in register that sets on/off.
Compare the state at INPUT with the state of LSn and dynamically
adjust how you program LSn
Signed-off-by: MarshallZhan <marshall_zhan@xxxxxxxxxx>
Signed-off-by: Delphine CC Chiu <delphine_cc_chiu@xxxxxxxxxx>
---
drivers/leds/leds-pca955x.c | 41 +++++++++++++++++++++++++++++++------
1 file changed, 35 insertions(+), 6 deletions(-)
diff --git a/drivers/leds/leds-pca955x.c b/drivers/leds/leds-pca955x.c
index 94a9f8a54b35..447da4a2d089 100644
--- a/drivers/leds/leds-pca955x.c
+++ b/drivers/leds/leds-pca955x.c
@@ -4,7 +4,7 @@
*
* Author: Nate Case <ncase@xxxxxxxxxxx>
*
- * LED driver for various PCA955x I2C LED drivers
+ * LED driver for various PCA955x and CAT9532 I2C LED drivers
*
* Supported devices:
*
@@ -145,6 +145,11 @@ static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state)
((state & 0x3) << (led_num << 1));
}
+static inline int pca955x_ledstate(u8 ls, int led_num)
+{
+ return (ls >> (led_num << 1)) & 0x3;
+}
+
/*
* Write to frequency prescaler register, used to program the
* period of the PWM output. period = (PSCx + 1) / 38
@@ -235,6 +240,21 @@ static int pca955x_read_pwm(struct i2c_client *client, int n, u8 *val)
return 0;
}
+static int pca955x_read_input_bit(struct pca955x *pca955x, int led_num)
+{
+ u8 cmd = led_num / 8;
+ int input_state;
+
+ input_state= i2c_smbus_read_byte_data(pca955x->client, cmd);
+ if (input_state < 0) {
+ dev_err(&pca955x->client->dev, "%s: reg 0x%x, err %d\n",
+ __func__, led_num, input_state);
+ return input_state;
+ }
+ return (input_state >> (led_num % 8)) & 1;
+
+}
+
static enum led_brightness pca955x_led_get(struct led_classdev *led_cdev)
{
struct pca955x_led *pca955x_led = container_of(led_cdev,
@@ -251,10 +271,11 @@ static enum led_brightness pca955x_led_get(struct led_classdev *led_cdev)
ls = (ls >> ((pca955x_led->led_num % 4) << 1)) & 0x3;
switch (ls) {
case PCA955X_LS_LED_ON:
- ret = LED_FULL;
- break;
case PCA955X_LS_LED_OFF:
- ret = LED_OFF;
+ if (pca955x_read_input_bit(pca955x, pca955x_led->led_num))
+ ret = LED_FULL;
+ else
+ ret = LED_OFF;
break;
case PCA955X_LS_BLINK0:
ret = LED_HALF;
@@ -276,6 +297,8 @@ static int pca955x_led_set(struct led_classdev *led_cdev,
struct pca955x_led *pca955x_led;
struct pca955x *pca955x;
u8 ls;
+ u8 ls_last_state;
+ int input_bit;
int chip_ls; /* which LSx to use (0-3 potentially) */
int ls_led; /* which set of bits within LSx to use (0-3) */
int ret;
@@ -292,12 +315,18 @@ static int pca955x_led_set(struct led_classdev *led_cdev,
if (ret)
goto out;
+ ls_last_state = pca955x_ledstate(ls, ls_led);
+ input_bit = pca955x_read_input_bit(pca955x, pca955x_led->led_num);
switch (value) {
case LED_FULL:
- ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON);
+ ls = pca955x_ledsel(ls, ls_led,
+ (ls_last_state == input_bit) ?
+ PCA955X_LS_LED_ON : PCA955X_LS_LED_OFF);
break;
case LED_OFF:
- ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF);
+ ls = pca955x_ledsel(ls, ls_led,
+ (ls_last_state == input_bit) ?
+ PCA955X_LS_LED_OFF : PCA955X_LS_LED_ON);
break;
case LED_HALF:
ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0);
--
2.25.1
