1 files changed, 320 insertions, 42 deletions

diff --git a/drivers/leds/leds-turris-omnia.c b/drivers/leds/leds-turris-omnia.c
index b8a95a917cfa..b443f8c989fa 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 by Marek Behún <kabel@kernel.org>
+ * 2020, 2023 by Marek Behún <kabel@kernel.org>
  */
 
 #include <linux/i2c.h>
@@ -15,21 +15,36 @@
 #define OMNIA_BOARD_LEDS	12
 #define OMNIA_LED_NUM_CHANNELS	3
 
-#define CMD_LED_MODE		3
-#define CMD_LED_MODE_LED(l)	((l) & 0x0f)
-#define CMD_LED_MODE_USER	0x10
+/* MCU controller commands at I2C address 0x2a */
+#define OMNIA_MCU_I2C_ADDR		0x2a
 
-#define CMD_LED_STATE		4
-#define CMD_LED_STATE_LED(l)	((l) & 0x0f)
-#define CMD_LED_STATE_ON	0x10
+#define CMD_GET_STATUS_WORD		0x01
+#define STS_FEATURES_SUPPORTED		BIT(2)
 
-#define CMD_LED_COLOR		5
-#define CMD_LED_SET_BRIGHTNESS	7
-#define CMD_LED_GET_BRIGHTNESS	8
+#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
 
 struct omnia_led {
 	struct led_classdev_mc mc_cdev;
 	struct mc_subled subled_info[OMNIA_LED_NUM_CHANNELS];
+	u8 cached_channels[OMNIA_LED_NUM_CHANNELS];
+	bool on, hwtrig;
 	int reg;
 };
 
@@ -38,41 +53,204 @@ struct omnia_led {
 struct omnia_leds {
 	struct i2c_client *client;
 	struct mutex lock;
+	bool has_gamma_correction;
 	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)
+{
+	u8 reply;
+	int err;
+
+	err = omnia_cmd_read_raw(client->adapter, client->addr, cmd, &reply, 1);
+	if (err)
+		return err;
+
+	return reply;
+}
+
+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);
+	if (ret < 0)
+		return ret;
+
+	/* Cache the RGB channel brightnesses */
+	for (int i = 0; i < OMNIA_LED_NUM_CHANNELS; ++i)
+		led->cached_channels[i] = led->subled_info[i].brightness;
+
+	return 0;
+}
+
+/* Determine if the computed RGB channels are different from the cached ones */
+static bool omnia_led_channels_changed(struct omnia_led *led)
+{
+	for (int i = 0; i < OMNIA_LED_NUM_CHANNELS; ++i)
+		if (led->subled_info[i].brightness != led->cached_channels[i])
+			return true;
+
+	return false;
+}
+
 static int omnia_led_brightness_set_blocking(struct led_classdev *cdev,
 					     enum led_brightness brightness)
 {
 	struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
 	struct omnia_leds *leds = dev_get_drvdata(cdev->dev->parent);
 	struct omnia_led *led = to_omnia_led(mc_cdev);
-	u8 buf[5], state;
-	int ret;
+	int err = 0;
 
 	mutex_lock(&leds->lock);
 
-	led_mc_calc_color_components(&led->mc_cdev, brightness);
+	/*
+	 * Only recalculate RGB brightnesses from intensities if brightness is
+	 * non-zero (if it is zero and the LED is in HW blinking mode, we use
+	 * max_brightness as brightness). Otherwise we won't be using them and
+	 * we can save ourselves some software divisions (Omnia's CPU does not
+	 * implement the division instruction).
+	 */
+	if (brightness || led->hwtrig) {
+		led_mc_calc_color_components(mc_cdev, brightness ?:
+						      cdev->max_brightness);
+
+		/*
+		 * Send color command only if brightness is non-zero and the RGB
+		 * channel brightnesses changed.
+		 */
+		if (omnia_led_channels_changed(led))
+			err = omnia_led_send_color_cmd(leds->client, led);
+	}
 
-	buf[0] = CMD_LED_COLOR;
-	buf[1] = led->reg;
-	buf[2] = mc_cdev->subled_info[0].brightness;
-	buf[3] = mc_cdev->subled_info[1].brightness;
-	buf[4] = mc_cdev->subled_info[2].brightness;
+	/*
+	 * Send on/off state change only if (bool)brightness changed and the LED
+	 * is not being blinked by HW.
+	 */
+	if (!err && !led->hwtrig && !brightness != !led->on) {
+		u8 state = CMD_LED_STATE_LED(led->reg);
+
+		if (brightness)
+			state |= CMD_LED_STATE_ON;
+
+		err = omnia_cmd_write_u8(leds->client, CMD_LED_STATE, state);
+		if (!err)
+			led->on = !!brightness;
+	}
+
+	mutex_unlock(&leds->lock);
+
+	return err;
+}
+
+static struct led_hw_trigger_type omnia_hw_trigger_type;
+
+static int omnia_hwtrig_activate(struct led_classdev *cdev)
+{
+	struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev);
+	struct omnia_leds *leds = dev_get_drvdata(cdev->dev->parent);
+	struct omnia_led *led = to_omnia_led(mc_cdev);
+	int err = 0;
+
+	mutex_lock(&leds->lock);
+
+	if (!led->on) {
+		/*
+		 * If the LED is off (brightness was set to 0), the last
+		 * configured color was not necessarily sent to the MCU.
+		 * Recompute with max_brightness and send if needed.
+		 */
+		led_mc_calc_color_components(mc_cdev, cdev->max_brightness);
+
+		if (omnia_led_channels_changed(led))
+			err = omnia_led_send_color_cmd(leds->client, led);
+	}
+
+	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));
+		if (!err)
+			led->hwtrig = true;
+	}
+
+	mutex_unlock(&leds->lock);
+
+	return err;
+}
 
-	state = CMD_LED_STATE_LED(led->reg);
-	if (buf[2] || buf[3] || buf[4])
-		state |= CMD_LED_STATE_ON;
+static void omnia_hwtrig_deactivate(struct led_classdev *cdev)
+{
+	struct omnia_leds *leds = dev_get_drvdata(cdev->dev->parent);
+	struct omnia_led *led = to_omnia_led(lcdev_to_mccdev(cdev));
+	int err;
 
-	ret = i2c_smbus_write_byte_data(leds->client, CMD_LED_STATE, state);
-	if (ret >= 0 && (state & CMD_LED_STATE_ON))
-		ret = i2c_master_send(leds->client, buf, 5);
+	mutex_lock(&leds->lock);
+
+	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);
 
 	mutex_unlock(&leds->lock);
 
-	return ret;
+	if (err)
+		dev_err(cdev->dev, "Cannot put LED to software mode: %i\n",
+			err);
 }
 
+static struct led_trigger omnia_hw_trigger = {
+	.name		= "omnia-mcu",
+	.activate	= omnia_hwtrig_activate,
+	.deactivate	= omnia_hwtrig_deactivate,
+	.trigger_type	= &omnia_hw_trigger_type,
+};
+
 static int omnia_led_register(struct i2c_client *client, struct omnia_led *led,
 			      struct device_node *np)
 {
@@ -98,11 +276,15 @@ static int omnia_led_register(struct i2c_client *client, struct omnia_led *led,
 	}
 
 	led->subled_info[0].color_index = LED_COLOR_ID_RED;
-	led->subled_info[0].channel = 0;
 	led->subled_info[1].color_index = LED_COLOR_ID_GREEN;
-	led->subled_info[1].channel = 1;
 	led->subled_info[2].color_index = LED_COLOR_ID_BLUE;
-	led->subled_info[2].channel = 2;
+
+	/* Initial color is white */
+	for (int i = 0; i < OMNIA_LED_NUM_CHANNELS; ++i) {
+		led->subled_info[i].intensity = 255;
+		led->subled_info[i].brightness = 255;
+		led->subled_info[i].channel = i;
+	}
 
 	led->mc_cdev.subled_info = led->subled_info;
 	led->mc_cdev.num_colors = OMNIA_LED_NUM_CHANNELS;
@@ -112,25 +294,39 @@ static int omnia_led_register(struct i2c_client *client, struct omnia_led *led,
 	cdev = &led->mc_cdev.led_cdev;
 	cdev->max_brightness = 255;
 	cdev->brightness_set_blocking = omnia_led_brightness_set_blocking;
+	cdev->trigger_type = &omnia_hw_trigger_type;
+	/*
+	 * Use the omnia-mcu trigger as the default trigger. It may be rewritten
+	 * by LED class from the linux,default-trigger property.
+	 */
+	cdev->default_trigger = omnia_hw_trigger.name;
 
 	/* put the LED into software mode */
-	ret = i2c_smbus_write_byte_data(client, CMD_LED_MODE,
-					CMD_LED_MODE_LED(led->reg) |
-					CMD_LED_MODE_USER);
-	if (ret < 0) {
+	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;
 	}
 
 	/* disable the LED */
-	ret = i2c_smbus_write_byte_data(client, CMD_LED_STATE,
-					CMD_LED_STATE_LED(led->reg));
-	if (ret < 0) {
+	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;
 	}
 
+	/* 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;
+	}
+
 	ret = devm_led_classdev_multicolor_register_ext(dev, &led->mc_cdev,
 							&init_data);
 	if (ret < 0) {
@@ -158,7 +354,7 @@ static ssize_t brightness_show(struct device *dev, struct device_attribute *a,
 	struct i2c_client *client = to_i2c_client(dev);
 	int ret;
 
-	ret = i2c_smbus_read_byte_data(client, CMD_LED_GET_BRIGHTNESS);
+	ret = omnia_cmd_read_u8(client, CMD_LED_GET_BRIGHTNESS);
 
 	if (ret < 0)
 		return ret;
@@ -171,7 +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;
@@ -179,19 +375,80 @@ static ssize_t brightness_store(struct device *dev, struct device_attribute *a,
 	if (brightness > 100)
 		return -EINVAL;
 
-	ret = i2c_smbus_write_byte_data(client, CMD_LED_SET_BRIGHTNESS,
-					(u8)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);
 
+static ssize_t gamma_correction_show(struct device *dev,
+				     struct device_attribute *a, char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct omnia_leds *leds = i2c_get_clientdata(client);
+	int ret;
+
+	if (leds->has_gamma_correction) {
+		ret = omnia_cmd_read_u8(client, CMD_GET_GAMMA_CORRECTION);
+		if (ret < 0)
+			return ret;
+	} else {
+		ret = 0;
+	}
+
+	return sysfs_emit(buf, "%d\n", !!ret);
+}
+
+static ssize_t gamma_correction_store(struct device *dev,
+				      struct device_attribute *a,
+				      const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct omnia_leds *leds = i2c_get_clientdata(client);
+	bool val;
+	int err;
+
+	if (!leds->has_gamma_correction)
+		return -EOPNOTSUPP;
+
+	if (kstrtobool(buf, &val) < 0)
+		return -EINVAL;
+
+	err = omnia_cmd_write_u8(client, CMD_SET_GAMMA_CORRECTION, val);
+
+	return err ?: count;
+}
+static DEVICE_ATTR_RW(gamma_correction);
+
 static struct attribute *omnia_led_controller_attrs[] = {
 	&dev_attr_brightness.attr,
+	&dev_attr_gamma_correction.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(omnia_led_controller);
 
+static int omnia_mcu_get_features(const struct i2c_client *client)
+{
+	u16 reply;
+	int err;
+
+	err = omnia_cmd_read_raw(client->adapter, OMNIA_MCU_I2C_ADDR,
+				 CMD_GET_STATUS_WORD, &reply, sizeof(reply));
+	if (err)
+		return err;
+
+	/* Check whether MCU firmware supports the CMD_GET_FEAUTRES command */
+	if (!(le16_to_cpu(reply) & STS_FEATURES_SUPPORTED))
+		return 0;
+
+	err = omnia_cmd_read_raw(client->adapter, OMNIA_MCU_I2C_ADDR,
+				 CMD_GET_FEATURES, &reply, sizeof(reply));
+	if (err)
+		return err;
+
+	return le16_to_cpu(reply);
+}
+
 static int omnia_leds_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
@@ -216,8 +473,29 @@ 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;
+	}
+
+	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");
+	}
+
 	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;
+	}
+
 	led = &leds->leds[0];
 	for_each_available_child_of_node(np, child) {
 		ret = omnia_led_register(client, led, child);
@@ -237,8 +515,8 @@ static void omnia_leds_remove(struct i2c_client *client)
 	u8 buf[5];
 
 	/* put all LEDs into default (HW triggered) mode */
-	i2c_smbus_write_byte_data(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;