Hi Vishwanatha,
On 4/26/21 7:59 AM, vishwanatha subbanna wrote:
Joel,
With the experiments that I have done, I can not express LEDs with PCA955X_TYPE_LED predominantly because LEDs won’t
retain states after the BMC reboot. I cooked a patch and tried but it does not work. I did an experiment where
I put the patch and then did a reboot and saw that the LEDs were [OFF] in the very early stage of probe itself.
From a9fe9e956c624c15a455b88cc05262358519a541 Mon Sep 17 00:00:00 2001
From: Vishwanatha Subbanna <vishwa@xxxxxxxxxxxxxxxxxx>
Date: Fri, 23 Apr 2021 06:57:56 -0500
Subject: [PATCH 1/2] leds: pca955x: Add support for default-state
Signed-off-by: Vishwanatha Subbanna <vishwa@xxxxxxxxxxxxxxxxxx>
---
drivers/leds/leds-pca955x.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/leds/leds-pca955x.c b/drivers/leds/leds-pca955x.c
index bf7ead4..987415b 100644
--- a/drivers/leds/leds-pca955x.c
+++ b/drivers/leds/leds-pca955x.c
@@ -130,6 +130,7 @@ struct pca955x_led {
char name[32];
u32 type;
const char *default_trigger;
+ const char *default_state;
};
struct pca955x_platform_data {
@@ -408,6 +409,8 @@ static int pca955x_gpio_direction_output(struct gpio_chip *gc,
fwnode_property_read_u32(child, "type", &pdata->leds[reg].type);
fwnode_property_read_string(child, "linux,default-trigger",
&pdata->leds[reg].default_trigger);
+ fwnode_property_read_string(child, "default-state",
+ &pdata->leds[reg].default_state);
}
pdata->num_leds = chip->bits;
@@ -520,8 +523,13 @@ static int pca955x_probe(struct i2c_client *client,
if (err)
return err;
- /* Turn off LED */
- err = pca955x_led_set(&pca955x_led->led_cdev, LED_OFF);
+ /* If the default-state is "keep", don't change states */
+ if (strcmp(pdata->leds[i].default_state, "keep")) {
+ if (!strcmp(pdata->leds[i].default_state, "on"))
+ err = pca955x_led_set(&pca955x_led->led_cdev, LED_ON);
+ else
+ err = pca955x_led_set(&pca955x_led->led_cdev, LED_OFF);
+ }
if (err)
return err;
}
—
1.8.3.1
For `leds-gpio`, Andrew had put a patch, but I don’t see how that can be mapped to PCA955X. https://github.com/torvalds/linux/commit/f5808ac158f2b16b686a3d3c0879c5d6048aba14
Jacek,
Please could you help me here ?.. I need to express LEDs as PCA955X_TYPE_LED and also retain states post BMC reboot.
If in your setup the LED controller loses power on reboot then there
is nothing you can do to retain the state.
--
Best regards,
Jacek Anaszewski
