leds: turris-omnia: Use command execution functions from the MCU driver

Use the MCU command execution functions from the MCU driver instead of
the ad-hoc implementation in the LED driver. This allows as to drop the
LED driver implementation, which is a duplicate.

Signed-off-by: Marek Behún <kabel@kernel.org>
Link: https://lore.kernel.org/r/20241111100355.6978-3-kabel@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>

Author: elkablo

drivers/leds/Kconfig

@@ -217,6 +217,7 @@ config LEDS_TURRIS_OMNIA
 	depends on I2C
 	depends on MACH_ARMADA_38X || COMPILE_TEST
 	depends on OF
+	depends on TURRIS_OMNIA_MCU
 	select LEDS_TRIGGERS
 	help
 	  This option enables basic support for the LEDs found on the front

drivers/leds/leds-turris-omnia.c

@@ -2,14 +2,15 @@
 /*
  * CZ.NIC's Turris Omnia LEDs driver
  *
- * 2020, 2023 by Marek Behún <kabel@kernel.org>
+ * 2020, 2023, 2024 by Marek Behún <kabel@kernel.org>
  */
 
 #include <linux/i2c.h>
 #include <linux/led-class-multicolor.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
+#include <linux/turris-omnia-mcu-interface.h>
 
 #define OMNIA_BOARD_LEDS	12
 #define OMNIA_LED_NUM_CHANNELS	3
@@ -56,66 +57,21 @@ struct omnia_leds {
 	struct omnia_led leds[];
 };
 
-static int omnia_cmd_write_u8(const struct i2c_client *client, u8 cmd, u8 val)
+static int omnia_cmd_set_color(const struct i2c_client *client, u8 led, u8 r, u8 g, u8 b)
 {
-	u8 buf[2] = { cmd, val };
-	int ret;
-
-	ret = i2c_master_send(client, buf, sizeof(buf));
+	u8 buf[5] = { CMD_LED_COLOR, led, r, g, b };
 
-	return ret < 0 ? ret : 0;
-}
-
-static int omnia_cmd_read_raw(struct i2c_adapter *adapter, u8 addr, u8 cmd,
-			      void *reply, size_t len)
-{
-	struct i2c_msg msgs[2];
-	int ret;
-
-	msgs[0].addr = addr;
-	msgs[0].flags = 0;
-	msgs[0].len = 1;
-	msgs[0].buf = &cmd;
-	msgs[1].addr = addr;
-	msgs[1].flags = I2C_M_RD;
-	msgs[1].len = len;
-	msgs[1].buf = reply;
-
-	ret = i2c_transfer(adapter, msgs, ARRAY_SIZE(msgs));
-	if (likely(ret == ARRAY_SIZE(msgs)))
-		return 0;
-	else if (ret < 0)
-		return ret;
-	else
-		return -EIO;
-}
-
-static int omnia_cmd_read_u8(const struct i2c_client *client, u8 cmd)
-{
-	u8 reply;
-	int err;
-
-	err = omnia_cmd_read_raw(client->adapter, client->addr, cmd, &reply, 1);
-	if (err)
-		return err;
-
-	return reply;
+	return omnia_cmd_write(client, buf, sizeof(buf));
 }
 
 static int omnia_led_send_color_cmd(const struct i2c_client *client,
 				    struct omnia_led *led)
 {
-	char cmd[5];
 	int ret;
 
-	cmd[0] = CMD_LED_COLOR;
-	cmd[1] = led->reg;
-	cmd[2] = led->subled_info[0].brightness;
-	cmd[3] = led->subled_info[1].brightness;
-	cmd[4] = led->subled_info[2].brightness;
-
 	/* Send the color change command */
-	ret = i2c_master_send(client, cmd, 5);
+	ret = omnia_cmd_set_color(client, led->reg, led->subled_info[0].brightness,
+				  led->subled_info[1].brightness, led->subled_info[2].brightness);
 	if (ret < 0)
 		return ret;
 
@@ -351,14 +307,14 @@ static ssize_t brightness_show(struct device *dev, struct device_attribute *a,
 			       char *buf)
 {
 	struct i2c_client *client = to_i2c_client(dev);
-	int ret;
-
-	ret = omnia_cmd_read_u8(client, CMD_LED_GET_BRIGHTNESS);
+	u8 reply;
+	int err;
 
-	if (ret < 0)
-		return ret;
+	err = omnia_cmd_read_u8(client, CMD_LED_GET_BRIGHTNESS, &reply);
+	if (err < 0)
+		return err;
 
-	return sysfs_emit(buf, "%d\n", ret);
+	return sysfs_emit(buf, "%d\n", reply);
 }
 
 static ssize_t brightness_store(struct device *dev, struct device_attribute *a,
@@ -385,17 +341,16 @@ static ssize_t gamma_correction_show(struct device *dev,
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct omnia_leds *leds = i2c_get_clientdata(client);
-	int ret;
+	u8 reply = 0;
+	int err;
 
 	if (leds->has_gamma_correction) {
-		ret = omnia_cmd_read_u8(client, CMD_GET_GAMMA_CORRECTION);
-		if (ret < 0)
-			return ret;
-	} else {
-		ret = 0;
+		err = omnia_cmd_read_u8(client, CMD_GET_GAMMA_CORRECTION, &reply);
+		if (err < 0)
+			return err;
 	}
 
-	return sysfs_emit(buf, "%d\n", !!ret);
+	return sysfs_emit(buf, "%d\n", !!reply);
 }
 
 static ssize_t gamma_correction_store(struct device *dev,
@@ -426,26 +381,51 @@ static struct attribute *omnia_led_controller_attrs[] = {
 };
 ATTRIBUTE_GROUPS(omnia_led_controller);
 
-static int omnia_mcu_get_features(const struct i2c_client *client)
+static int omnia_mcu_get_features(const struct i2c_client *mcu_client)
 {
 	u16 reply;
 	int err;
 
-	err = omnia_cmd_read_raw(client->adapter, OMNIA_MCU_I2C_ADDR,
-				 CMD_GET_STATUS_WORD, &reply, sizeof(reply));
+	err = omnia_cmd_read_u16(mcu_client, CMD_GET_STATUS_WORD, &reply);
 	if (err)
 		return err;
 
 	/* Check whether MCU firmware supports the CMD_GET_FEAUTRES command */
-	if (!(le16_to_cpu(reply) & STS_FEATURES_SUPPORTED))
+	if (!(reply & STS_FEATURES_SUPPORTED))
 		return 0;
 
-	err = omnia_cmd_read_raw(client->adapter, OMNIA_MCU_I2C_ADDR,
-				 CMD_GET_FEATURES, &reply, sizeof(reply));
+	err = omnia_cmd_read_u16(mcu_client, CMD_GET_FEATURES, &reply);
 	if (err)
 		return err;
 
-	return le16_to_cpu(reply);
+	return reply;
+}
+
+static int omnia_match_mcu_client(struct device *dev, void *data)
+{
+	struct i2c_client *client;
+
+	client = i2c_verify_client(dev);
+	if (!client)
+		return 0;
+
+	return client->addr == OMNIA_MCU_I2C_ADDR;
+}
+
+static int omnia_find_mcu_and_get_features(struct device *dev)
+{
+	struct device *mcu_dev;
+	int ret;
+
+	mcu_dev = device_find_child(dev->parent, NULL, omnia_match_mcu_client);
+	if (!mcu_dev)
+		return -ENODEV;
+
+	ret = omnia_mcu_get_features(i2c_verify_client(mcu_dev));
+
+	put_device(mcu_dev);
+
+	return ret;
 }
 
 static int omnia_leds_probe(struct i2c_client *client)
@@ -472,7 +452,7 @@ static int omnia_leds_probe(struct i2c_client *client)
 	leds->client = client;
 	i2c_set_clientdata(client, leds);
 
-	ret = omnia_mcu_get_features(client);
+	ret = omnia_find_mcu_and_get_features(dev);
 	if (ret < 0) {
 		dev_err(dev, "Cannot determine MCU supported features: %d\n",
 			ret);
@@ -509,20 +489,11 @@ static int omnia_leds_probe(struct i2c_client *client)
 
 static void omnia_leds_remove(struct i2c_client *client)
 {
-	u8 buf[5];
-
 	/* put all LEDs into default (HW triggered) mode */
-	omnia_cmd_write_u8(client, CMD_LED_MODE,
-			   CMD_LED_MODE_LED(OMNIA_BOARD_LEDS));
+	omnia_cmd_write_u8(client, CMD_LED_MODE, CMD_LED_MODE_LED(OMNIA_BOARD_LEDS));
 
 	/* set all LEDs color to [255, 255, 255] */
-	buf[0] = CMD_LED_COLOR;
-	buf[1] = OMNIA_BOARD_LEDS;
-	buf[2] = 255;
-	buf[3] = 255;
-	buf[4] = 255;
-
-	i2c_master_send(client, buf, 5);
+	omnia_cmd_set_color(client, OMNIA_BOARD_LEDS, 255, 255, 255);
 }
 
 static const struct of_device_id of_omnia_leds_match[] = {