Commit 78cbcfd8 authored by Marek Behún's avatar Marek Behún Committed by Lee Jones
Browse files

leds: turris-omnia: Fix brightness setting and trigger activating 

I have improperly refactored commits
  4d5ed2621c24 ("leds: turris-omnia: Make set_brightness() more efficient")
and
  aaf38273cf76 ("leds: turris-omnia: Support HW controlled mode via private trigger")
after Lee requested a change in API semantics of the new functions I
introduced in commit
  28350bc0ac77 ("leds: turris-omnia: Do not use SMBUS calls").

Before the change, the function omnia_cmd_write_u8() returned 0 on
success, and afterwards it returned a positive value (number of bytes
written). The latter version was applied, but the following commits did
not properly account for this change.

This results in non-functional LED's .brightness_set_blocking() and
trigger's .activate() methods.

The main reasoning behind the semantics change was that read/write
methods should return the number of read/written bytes on success.
It was pointed to me [1] that this is not always true (for example the
regmap API does not do so), and since the driver never uses this number
of read/written bytes information, I decided to fix this issue by
changing the functions to the original semantics (return 0 on success).

[1] https://lore.kernel.org/linux-gpio/ZQnn+Gi0xVlsGCYA@smile.fi.intel.com/



Fixes: 28350bc0ac77 ("leds: turris-omnia: Do not use SMBUS calls")
Signed-off-by: default avatarMarek Behún <kabel@kernel.org>
Link: https://lore.kernel.org/r/20231016141538.30037-1-kabel@kernel.org


Signed-off-by: default avatarLee Jones <lee@kernel.org>
parent 50be9e02

drivers/leds/leds-turris-omnia.c

+20 −17
Original line number Diff line number Diff line
@@ -60,8 +60,11 @@ struct omnia_leds { 
static int omnia_cmd_write_u8(const struct i2c_client *client, u8 cmd, u8 val)

{

	u8 buf[2] = { cmd, val };

	int ret;



	ret = i2c_master_send(client, buf, sizeof(buf));



	return i2c_master_send(client, buf, sizeof(buf));

	return ret < 0 ? ret : 0;

}



static int omnia_cmd_read_raw(struct i2c_adapter *adapter, u8 addr, u8 cmd,
@@ -81,7 +84,7 @@ static int omnia_cmd_read_raw(struct i2c_adapter *adapter, u8 addr, u8 cmd, 


	ret = i2c_transfer(adapter, msgs, ARRAY_SIZE(msgs));

	if (likely(ret == ARRAY_SIZE(msgs)))

		return len;

		return 0;

	else if (ret < 0)

		return ret;

	else
@@ -91,11 +94,11 @@ static int omnia_cmd_read_raw(struct i2c_adapter *adapter, u8 addr, u8 cmd, 
static int omnia_cmd_read_u8(const struct i2c_client *client, u8 cmd)

{

	u8 reply;

	int ret;

	int err;



	ret = omnia_cmd_read_raw(client->adapter, client->addr, cmd, &reply, 1);

	if (ret < 0)

		return ret;

	err = omnia_cmd_read_raw(client->adapter, client->addr, cmd, &reply, 1);

	if (err)

		return err;



	return reply;

}
@@ -236,7 +239,7 @@ static void omnia_hwtrig_deactivate(struct led_classdev *cdev) 


	mutex_unlock(&leds->lock);



	if (err < 0)

	if (err)

		dev_err(cdev->dev, "Cannot put LED to software mode: %i\n",

			err);

}
@@ -302,7 +305,7 @@ static int omnia_led_register(struct i2c_client *client, struct omnia_led *led, 
	ret = omnia_cmd_write_u8(client, CMD_LED_MODE,

				 CMD_LED_MODE_LED(led->reg) |

				 CMD_LED_MODE_USER);

	if (ret < 0) {

	if (ret) {

		dev_err(dev, "Cannot set LED %pOF to software mode: %i\n", np,

			ret);

		return ret;
@@ -311,7 +314,7 @@ static int omnia_led_register(struct i2c_client *client, struct omnia_led *led, 
	/* disable the LED */

	ret = omnia_cmd_write_u8(client, CMD_LED_STATE,

				 CMD_LED_STATE_LED(led->reg));

	if (ret < 0) {

	if (ret) {

		dev_err(dev, "Cannot set LED %pOF brightness: %i\n", np, ret);

		return ret;

	}
@@ -364,7 +367,7 @@ static ssize_t brightness_store(struct device *dev, struct device_attribute *a, 
{

	struct i2c_client *client = to_i2c_client(dev);

	unsigned long brightness;

	int ret;

	int err;



	if (kstrtoul(buf, 10, &brightness))

		return -EINVAL;
@@ -372,9 +375,9 @@ static ssize_t brightness_store(struct device *dev, struct device_attribute *a, 
	if (brightness > 100)

		return -EINVAL;



	ret = omnia_cmd_write_u8(client, CMD_LED_SET_BRIGHTNESS, brightness);

	err = omnia_cmd_write_u8(client, CMD_LED_SET_BRIGHTNESS, brightness);



	return ret < 0 ? ret : count;

	return err ?: count;

}

static DEVICE_ATTR_RW(brightness);
@@ -403,7 +406,7 @@ static ssize_t gamma_correction_store(struct device *dev, 
	struct i2c_client *client = to_i2c_client(dev);

	struct omnia_leds *leds = i2c_get_clientdata(client);

	bool val;

	int ret;

	int err;



	if (!leds->has_gamma_correction)

		return -EOPNOTSUPP;
@@ -411,9 +414,9 @@ static ssize_t gamma_correction_store(struct device *dev, 
	if (kstrtobool(buf, &val) < 0)

		return -EINVAL;



	ret = omnia_cmd_write_u8(client, CMD_SET_GAMMA_CORRECTION, val);

	err = omnia_cmd_write_u8(client, CMD_SET_GAMMA_CORRECTION, val);



	return ret < 0 ? ret : count;

	return err ?: count;

}

static DEVICE_ATTR_RW(gamma_correction);
@@ -431,7 +434,7 @@ static int omnia_mcu_get_features(const struct i2c_client *client) 


	err = omnia_cmd_read_raw(client->adapter, OMNIA_MCU_I2C_ADDR,

				 CMD_GET_STATUS_WORD, &reply, sizeof(reply));

	if (err < 0)

	if (err)

		return err;



	/* Check whether MCU firmware supports the CMD_GET_FEAUTRES command */
@@ -440,7 +443,7 @@ static int omnia_mcu_get_features(const struct i2c_client *client) 


	err = omnia_cmd_read_raw(client->adapter, OMNIA_MCU_I2C_ADDR,

				 CMD_GET_FEATURES, &reply, sizeof(reply));

	if (err < 0)

	if (err)

		return err;



	return le16_to_cpu(reply);