This patch extends the device tree support for the pca9532 allowing LEDs to
blink, dim or even being unchanged, i.e. not being turned off during driver
initialization.
Signed-off-by: Felix Brack <f...@ltec.ch>
---
.../devicetree/bindings/leds/leds-pca9532.txt | 22 ++++++++++++
drivers/leds/leds-pca9532.c | 41 +++++++++++++++++++++-
include/linux/leds-pca9532.h | 4 +--
3 files changed, 64 insertions(+), 3 deletions(-)
diff --git a/Documentation/devicetree/bindings/leds/leds-pca9532.txt
b/Documentation/devicetree/bindings/leds/leds-pca9532.txt
index 198f3ba..81b6563 100644
--- a/Documentation/devicetree/bindings/leds/leds-pca9532.txt
+++ b/Documentation/devicetree/bindings/leds/leds-pca9532.txt
@@ -11,12 +11,24 @@ Required properties:
"nxp,pca9533"
- reg - I2C slave address
+Optional properties:
+ - psc0: 8 bit prescaler value according to NXP data sheet
+ - pwm0: 8 bit PWM value according to NXP data sheet
+ - psc1: 8 bit prescaler value according to NXP data sheet
+ - pwm1: 8 bit PWM value according to NXP data sheet
+
Each led is represented as a sub-node of the nxp,pca9530.
Optional sub-node properties:
- label: see Documentation/devicetree/bindings/leds/common.txt
- type: Output configuration, see dt-bindings/leds/leds-pca9532.h
(default NONE)
- linux,default-trigger: see
Documentation/devicetree/bindings/leds/common.txt
+ - default-state: see Documentation/devicetree/bindings/leds/common.txt
+ This property is only valid for sub-nodes of type <PCA9532_TYPE_LED>.
+ In addition to the values mentioned in the document above the
additional
+ values "pwm0" and "pwm1" are valid. The corresponding LED will blink
+ or will be dimmed depending on the configuration of prescaler and pwm
+ values (see optional node properties above).
Example:
#include <dt-bindings/leds/leds-pca9532.h>
@@ -24,6 +36,8 @@ Example:
leds: pca9530@60 {
compatible = "nxp,pca9530";
reg = <0x60>;
+ psc0 = <0x97>; // blink frequency 1Hz
+ pwm0 = <0x80>; // 50% duty cycle (500ms On / 500ms Off)
red-power {
label = "pca:red:power";
@@ -33,6 +47,14 @@ Example:
label = "pca:green:power";
type = <PCA9532_TYPE_LED>;
};
+ kernel-booting {
+ type = <PCA9532_TYPE_LED>;
+ default-state = "pwm0";
+ };
+ sys-stat {
+ type = <PCA9532_TYPE_LED>;
+ default-state = "keep"; // don't touch, was set by U-Boot
+ };
};
For more product information please see the link below:
diff --git a/drivers/leds/leds-pca9532.c b/drivers/leds/leds-pca9532.c
index 06e6310..3353739 100644
--- a/drivers/leds/leds-pca9532.c
+++ b/drivers/leds/leds-pca9532.c
@@ -254,6 +254,21 @@ static void pca9532_input_work(struct work_struct *work)
mutex_unlock(&data->update_lock);
}
+static enum pca9532_state pca9532_getled(struct pca9532_led *led)
+{
+ struct i2c_client *client = led->client;
+ struct pca9532_data *data = i2c_get_clientdata(client);
+ u8 maxleds = data->chip_info->num_leds;
+ char reg;
+ enum pca9532_state ret;
+
+ mutex_lock(&data->update_lock);
+ reg = i2c_smbus_read_byte_data(client, LED_REG(maxleds, led->id));
+ ret = reg >> LED_NUM(led->id)/2;
+ mutex_unlock(&data->update_lock);
+ return ret;
+}
+
#ifdef CONFIG_LEDS_PCA9532_GPIO
static int pca9532_gpio_request_pin(struct gpio_chip *gc, unsigned offset)
{
@@ -366,7 +381,10 @@ static int pca9532_configure(struct i2c_client *client,
gpios++;
break;
case PCA9532_TYPE_LED:
- led->state = pled->state;
+ if (pled->state == PCA9532_KEEP)
+ led->state = pca9532_getled(led);
+ else
+ led->state = pled->state;
led->name = pled->name;
led->ldev.name = led->name;
led->ldev.default_trigger = pled->default_trigger;
@@ -456,6 +474,8 @@ pca9532_of_populate_pdata(struct device *dev, struct
device_node *np)
const struct of_device_id *match;
int devid, maxleds;
int i = 0;
+ const char *state;
+ u32 val;
match = of_match_device(of_pca9532_leds_match, dev);
if (!match)
@@ -468,6 +488,15 @@ pca9532_of_populate_pdata(struct device *dev, struct
device_node *np)
if (!pdata)
return ERR_PTR(-ENOMEM);
+ if (!of_property_read_u32(np, "psc0", &val))
+ pdata->psc[0] = val & 0xff;
+ if (!of_property_read_u32(np, "pwm0", &val))
+ pdata->pwm[0] = val & 0xff;
+ if (!of_property_read_u32(np, "psc1", &val))
+ pdata->psc[1] = val & 0xff;
+ if (!of_property_read_u32(np, "pwm1", &val))
+ pdata->pwm[1] = val & 0xff;
+
for_each_child_of_node(np, child) {
if (of_property_read_string(child, "label",
&pdata->leds[i].name))
@@ -475,6 +504,16 @@ pca9532_of_populate_pdata(struct device *dev, struct
device_node *np)
of_property_read_u32(child, "type", &pdata->leds[i].type);
of_property_read_string(child, "linux,default-trigger",
&pdata->leds[i].default_trigger);
+ if (!of_property_read_string(child, "default-state", &state)) {
+ if (!strcmp(state, "on"))
+ pdata->leds[i].state = PCA9532_ON;
+ else if (!strcmp(state, "keep"))
+ pdata->leds[i].state = PCA9532_KEEP;
+ else if (!strcmp(state, "pwm0"))
+ pdata->leds[i].state = PCA9532_PWM0;
+ else if (!strcmp(state, "pwm1"))
+ pdata->leds[i].state = PCA9532_PWM1;
+ }
if (++i >= maxleds) {
of_node_put(child);
break;
diff --git a/include/linux/leds-pca9532.h b/include/linux/leds-pca9532.h
index d215b45..a327b1aa 100644
--- a/include/linux/leds-pca9532.h
+++ b/include/linux/leds-pca9532.h
@@ -22,7 +22,8 @@ enum pca9532_state {
PCA9532_OFF = 0x0,
PCA9532_ON = 0x1,
PCA9532_PWM0 = 0x2,
- PCA9532_PWM1 = 0x3
+ PCA9532_PWM1 = 0x3,
+ PCA9532_KEEP = 0xff
};
struct pca9532_led {
@@ -44,4 +45,3 @@ struct pca9532_platform_data {
};
#endif /* __LINUX_PCA9532_H */
-
--
2.7.4
