1 files changed, 168 insertions, 168 deletions

diff --git a/drivers/leds/leds-turris-omnia.c b/drivers/leds/leds-turris-omnia.c
index 2de825ac08b3..7d3b24c8ecae 100644
--- a/drivers/leds/leds-turris-omnia.c
+++ b/drivers/leds/leds-turris-omnia.c
@@ -2,7 +2,7 @@
 /*
  * 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>
@@ -10,35 +10,23 @@
 #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
 
-/* MCU controller commands at I2C address 0x2a */
-#define OMNIA_MCU_I2C_ADDR		0x2a
-
-#define CMD_GET_STATUS_WORD		0x01
-#define STS_FEATURES_SUPPORTED		BIT(2)
-
-#define CMD_GET_FEATURES		0x10
-#define FEAT_LED_GAMMA_CORRECTION	BIT(5)
-
-/* LED controller commands at I2C address 0x2b */
-#define CMD_LED_MODE			0x03
-#define CMD_LED_MODE_LED(l)		((l) & 0x0f)
-#define CMD_LED_MODE_USER		0x10
-
-#define CMD_LED_STATE			0x04
-#define CMD_LED_STATE_LED(l)		((l) & 0x0f)
-#define CMD_LED_STATE_ON		0x10
-
-#define CMD_LED_COLOR			0x05
-#define CMD_LED_SET_BRIGHTNESS		0x07
-#define CMD_LED_GET_BRIGHTNESS		0x08
-
-#define CMD_SET_GAMMA_CORRECTION	0x30
-#define CMD_GET_GAMMA_CORRECTION	0x31
-
+/* MCU controller I2C address 0x2a, needed for detecting MCU features */
+#define OMNIA_MCU_I2C_ADDR	0x2a
+
+/**
+ * struct omnia_led - per-LED part of driver private data structure
+ * @mc_cdev:		multi-color LED class device
+ * @subled_info:	per-channel information
+ * @cached_channels:	cached values of per-channel brightness that was sent to the MCU
+ * @on:			whether the LED was set on
+ * @hwtrig:		whether the LED blinking was offloaded to the MCU
+ * @reg:		LED identifier to the MCU
+ */
 struct omnia_led {
 	struct led_classdev_mc mc_cdev;
 	struct mc_subled subled_info[OMNIA_LED_NUM_CHANNELS];
@@ -49,73 +37,38 @@ struct omnia_led {
 
 #define to_omnia_led(l)		container_of(l, struct omnia_led, mc_cdev)
 
+/**
+ * struct omnia_leds - driver private data structure
+ * @client:			I2C client device
+ * @lock:			mutex to protect cached state
+ * @has_gamma_correction:	whether the MCU firmware supports gamma correction
+ * @brightness_knode:		kernel node of the "brightness" device sysfs attribute (this is the
+ *				driver specific global brightness, not the LED classdev brightness)
+ * @leds:			flexible array of per-LED data
+ */
 struct omnia_leds {
 	struct i2c_client *client;
 	struct mutex lock;
 	bool has_gamma_correction;
+	struct kernfs_node *brightness_knode;
 	struct omnia_led 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 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)
+static int omnia_cmd_set_color(const struct i2c_client *client, u8 led, u8 r, u8 g, u8 b)
 {
-	u8 reply;
-	int err;
+	u8 buf[5] = { OMNIA_CMD_LED_COLOR, led, r, g, b };
 
-	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;
 
@@ -170,12 +123,12 @@ static int omnia_led_brightness_set_blocking(struct led_classdev *cdev,
 	 * is not being blinked by HW.
 	 */
 	if (!err && !led->hwtrig && !brightness != !led->on) {
-		u8 state = CMD_LED_STATE_LED(led->reg);
+		u8 state = OMNIA_CMD_LED_STATE_LED(led->reg);
 
 		if (brightness)
-			state |= CMD_LED_STATE_ON;
+			state |= OMNIA_CMD_LED_STATE_ON;
 
-		err = omnia_cmd_write_u8(leds->client, CMD_LED_STATE, state);
+		err = omnia_cmd_write_u8(leds->client, OMNIA_CMD_LED_STATE, state);
 		if (!err)
 			led->on = !!brightness;
 	}
@@ -210,8 +163,8 @@ static int omnia_hwtrig_activate(struct led_classdev *cdev)
 
 	if (!err) {
 		/* Put the LED into MCU controlled mode */
-		err = omnia_cmd_write_u8(leds->client, CMD_LED_MODE,
-					 CMD_LED_MODE_LED(led->reg));
+		err = omnia_cmd_write_u8(leds->client, OMNIA_CMD_LED_MODE,
+					 OMNIA_CMD_LED_MODE_LED(led->reg));
 		if (!err)
 			led->hwtrig = true;
 	}
@@ -232,9 +185,8 @@ static void omnia_hwtrig_deactivate(struct led_classdev *cdev)
 	led->hwtrig = false;
 
 	/* Put the LED into software mode */
-	err = omnia_cmd_write_u8(leds->client, CMD_LED_MODE,
-				 CMD_LED_MODE_LED(led->reg) |
-				 CMD_LED_MODE_USER);
+	err = omnia_cmd_write_u8(leds->client, OMNIA_CMD_LED_MODE,
+				 OMNIA_CMD_LED_MODE_LED(led->reg) | OMNIA_CMD_LED_MODE_USER);
 
 	mutex_unlock(&leds->lock);
 
@@ -300,38 +252,26 @@ static int omnia_led_register(struct i2c_client *client, struct omnia_led *led,
 	 */
 	cdev->default_trigger = omnia_hw_trigger.name;
 
-	/* put the LED into software mode */
-	ret = omnia_cmd_write_u8(client, CMD_LED_MODE,
-				 CMD_LED_MODE_LED(led->reg) |
-				 CMD_LED_MODE_USER);
-	if (ret) {
-		dev_err(dev, "Cannot set LED %pOF to software mode: %i\n", np,
-			ret);
-		return ret;
-	}
+	/* Put the LED into software mode */
+	ret = omnia_cmd_write_u8(client, OMNIA_CMD_LED_MODE, OMNIA_CMD_LED_MODE_LED(led->reg) |
+							     OMNIA_CMD_LED_MODE_USER);
+	if (ret)
+		return dev_err_probe(dev, ret, "Cannot set LED %pOF to software mode\n", np);
 
-	/* disable the LED */
-	ret = omnia_cmd_write_u8(client, CMD_LED_STATE,
-				 CMD_LED_STATE_LED(led->reg));
-	if (ret) {
-		dev_err(dev, "Cannot set LED %pOF brightness: %i\n", np, ret);
-		return ret;
-	}
+	/* Disable the LED */
+	ret = omnia_cmd_write_u8(client, OMNIA_CMD_LED_STATE, OMNIA_CMD_LED_STATE_LED(led->reg));
+	if (ret)
+		return dev_err_probe(dev, ret, "Cannot set LED %pOF brightness\n", np);
 
 	/* Set initial color and cache it */
 	ret = omnia_led_send_color_cmd(client, led);
-	if (ret < 0) {
-		dev_err(dev, "Cannot set LED %pOF initial color: %i\n", np,
-			ret);
-		return ret;
-	}
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Cannot set LED %pOF initial color\n", np);
 
 	ret = devm_led_classdev_multicolor_register_ext(dev, &led->mc_cdev,
 							&init_data);
-	if (ret < 0) {
-		dev_err(dev, "Cannot register LED %pOF: %i\n", np, ret);
-		return ret;
-	}
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Cannot register LED %pOF\n", np);
 
 	return 1;
 }
@@ -351,14 +291,14 @@ 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, OMNIA_CMD_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,
@@ -374,7 +314,7 @@ static ssize_t brightness_store(struct device *dev, struct device_attribute *a,
 	if (brightness > 100)
 		return -EINVAL;
 
-	err = omnia_cmd_write_u8(client, CMD_LED_SET_BRIGHTNESS, brightness);
+	err = omnia_cmd_write_u8(client, OMNIA_CMD_SET_BRIGHTNESS, brightness);
 
 	return err ?: count;
 }
@@ -385,17 +325,16 @@ 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, OMNIA_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,
@@ -413,7 +352,7 @@ static ssize_t gamma_correction_store(struct device *dev,
 	if (kstrtobool(buf, &val) < 0)
 		return -EINVAL;
 
-	err = omnia_cmd_write_u8(client, CMD_SET_GAMMA_CORRECTION, val);
+	err = omnia_cmd_write_u8(client, OMNIA_CMD_SET_GAMMA_CORRECTION, val);
 
 	return err ?: count;
 }
@@ -426,26 +365,104 @@ static struct attribute *omnia_led_controller_attrs[] = {
 };
 ATTRIBUTE_GROUPS(omnia_led_controller);
 
-static int omnia_mcu_get_features(const struct i2c_client *client)
+static irqreturn_t omnia_brightness_changed_threaded_fn(int irq, void *data)
+{
+	struct omnia_leds *leds = data;
+
+	if (unlikely(!leds->brightness_knode)) {
+		/*
+		 * Note that sysfs_get_dirent() may sleep. This is okay, because we are in threaded
+		 * context.
+		 */
+		leds->brightness_knode = sysfs_get_dirent(leds->client->dev.kobj.sd, "brightness");
+		if (!leds->brightness_knode)
+			return IRQ_NONE;
+	}
+
+	sysfs_notify_dirent(leds->brightness_knode);
+
+	return IRQ_HANDLED;
+}
+
+static void omnia_brightness_knode_put(void *data)
+{
+	struct omnia_leds *leds = data;
+
+	if (leds->brightness_knode)
+		sysfs_put(leds->brightness_knode);
+}
+
+static int omnia_request_brightness_irq(struct omnia_leds *leds)
+{
+	struct device *dev = &leds->client->dev;
+	int ret;
+
+	if (!leds->client->irq) {
+		dev_info(dev,
+			 "Brightness change interrupt supported by MCU firmware but not described in device-tree\n");
+
+		return 0;
+	}
+
+	/*
+	 * Registering the brightness_knode destructor before requesting the IRQ ensures that on
+	 * removal the brightness_knode sysfs node is put only after the IRQ is freed.
+	 * This is needed because the interrupt handler uses the knode.
+	 */
+	ret = devm_add_action(dev, omnia_brightness_knode_put, leds);
+	if (ret < 0)
+		return ret;
+
+	return devm_request_threaded_irq(dev, leds->client->irq, NULL,
+					 omnia_brightness_changed_threaded_fn, IRQF_ONESHOT,
+					 "leds-turris-omnia", leds);
+}
+
+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, OMNIA_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))
+	/* Check whether MCU firmware supports the OMNIA_CMD_GET_FEAUTRES command */
+	if (!(reply & OMNIA_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, OMNIA_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)
@@ -457,13 +474,10 @@ static int omnia_leds_probe(struct i2c_client *client)
 	int ret, count;
 
 	count = of_get_available_child_count(np);
-	if (!count) {
-		dev_err(dev, "LEDs are not defined in device tree!\n");
-		return -ENODEV;
-	} else if (count > OMNIA_BOARD_LEDS) {
-		dev_err(dev, "Too many LEDs defined in device tree!\n");
-		return -EINVAL;
-	}
+	if (count == 0)
+		return dev_err_probe(dev, -ENODEV, "LEDs are not defined in device tree!\n");
+	if (count > OMNIA_BOARD_LEDS)
+		return dev_err_probe(dev, -EINVAL, "Too many LEDs defined in device tree!\n");
 
 	leds = devm_kzalloc(dev, struct_size(leds, leds, count), GFP_KERNEL);
 	if (!leds)
@@ -472,28 +486,23 @@ static int omnia_leds_probe(struct i2c_client *client)
 	leds->client = client;
 	i2c_set_clientdata(client, leds);
 
-	ret = omnia_mcu_get_features(client);
-	if (ret < 0) {
-		dev_err(dev, "Cannot determine MCU supported features: %d\n",
-			ret);
-		return ret;
-	}
+	ret = omnia_find_mcu_and_get_features(dev);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Cannot determine MCU supported features\n");
 
-	leds->has_gamma_correction = ret & FEAT_LED_GAMMA_CORRECTION;
-	if (!leds->has_gamma_correction) {
-		dev_info(dev,
-			 "Your board's MCU firmware does not support the LED gamma correction feature.\n");
-		dev_info(dev,
-			 "Consider upgrading MCU firmware with the omnia-mcutool utility.\n");
+	leds->has_gamma_correction = ret & OMNIA_FEAT_LED_GAMMA_CORRECTION;
+
+	if (ret & OMNIA_FEAT_BRIGHTNESS_INT) {
+		ret = omnia_request_brightness_irq(leds);
+		if (ret < 0)
+			return dev_err_probe(dev, ret, "Cannot request brightness IRQ\n");
 	}
 
 	mutex_init(&leds->lock);
 
 	ret = devm_led_trigger_register(dev, &omnia_hw_trigger);
-	if (ret < 0) {
-		dev_err(dev, "Cannot register private LED trigger: %d\n", ret);
-		return ret;
-	}
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Cannot register private LED trigger\n");
 
 	led = &leds->leds[0];
 	for_each_available_child_of_node_scoped(np, child) {
@@ -509,20 +518,11 @@ 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));
-
-	/* 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;
+	/* Put all LEDs into default (HW triggered) mode */
+	omnia_cmd_write_u8(client, OMNIA_CMD_LED_MODE, OMNIA_CMD_LED_MODE_LED(OMNIA_BOARD_LEDS));
 
-	i2c_master_send(client, buf, 5);
+	/* Set all LEDs color to [255, 255, 255] */
+	omnia_cmd_set_color(client, OMNIA_BOARD_LEDS, 255, 255, 255);
 }
 
 static const struct of_device_id of_omnia_leds_match[] = {