On Sun, 25 Aug 2024, Heiko Stuebner wrote:

Superfluous line.

+/*
+ * Driver for LEDs found on QNAP MCU devices
+ *
+ * Copyright (C) 2024 Heiko Stuebner [off-list ref]
+ */
+
+#include <linux/leds.h>
+#include <linux/mfd/qnap-mcu.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <uapi/linux/uleds.h>
+
+enum qnap_mcu_err_led_mode {
+	QNAP_MCU_ERR_LED_ON = 0,
+	QNAP_MCU_ERR_LED_OFF = 1,
+	QNAP_MCU_ERR_LED_BLINK_FAST = 2,
+	QNAP_MCU_ERR_LED_BLINK_SLOW = 3,
+};
+
+struct qnap_mcu_err_led {
+	struct qnap_mcu *mcu;
+	struct led_classdev cdev;
+	char name[LED_MAX_NAME_SIZE];
+	u8 num;
+	u8 mode;
+};
+
+static inline struct qnap_mcu_err_led *
+		cdev_to_qnap_mcu_err_led(struct led_classdev *led_cdev)
+{
+	return container_of(led_cdev, struct qnap_mcu_err_led, cdev);
+}
+
+static int qnap_mcu_err_led_set(struct led_classdev *led_cdev,
+				enum led_brightness value)

'value' is a terrible variable name.

Please describe the data.  'brightness' seems appropriate.

+{
+	struct qnap_mcu_err_led *err_led = cdev_to_qnap_mcu_err_led(led_cdev);
+	u8 cmd[] = { 0x40, 0x52, 0x30 + err_led->num, 0x30 };

Really not fan of these magic values being used raw like this.

+	/* Don't disturb a possible set blink-mode if LED is already on */

Why not save cycles and return if blink mode is already enabled?

+	if (value == 0)
+		err_led->mode = QNAP_MCU_ERR_LED_OFF;
+	else if (err_led->mode == QNAP_MCU_ERR_LED_OFF)
+		err_led->mode = QNAP_MCU_ERR_LED_ON;

Then you can do:

	err_led->mode = value ? QNAP_MCU_ERR_LED_ON : QNAP_MCU_ERR_LED_OFF;

+	cmd[3] = 0x30 + err_led->mode;
+
+	return qnap_mcu_exec_with_ack(err_led->mcu, cmd, sizeof(cmd));
+}
+
+static int qnap_mcu_err_led_blink_set(struct led_classdev *led_cdev,
+				      unsigned long *delay_on,
+				      unsigned long *delay_off)
+{
+	struct qnap_mcu_err_led *err_led = cdev_to_qnap_mcu_err_led(led_cdev);
+	u8 cmd[] = { 0x40, 0x52, 0x30 + err_led->num, 0x30 };
+
+	/* LED is off, nothing to do */
+	if (err_led->mode == QNAP_MCU_ERR_LED_OFF)
+		return 0;
+
+	if (*delay_on < 500) {

Setting delay_on based on the current value of delay_on sounds sketchy.

+		*delay_on = 100;
+		*delay_off = 100;
+		err_led->mode = QNAP_MCU_ERR_LED_BLINK_FAST;
+	} else {
+		*delay_on = 500;
+		*delay_off = 500;
+		err_led->mode = QNAP_MCU_ERR_LED_BLINK_SLOW;
+	}

How do you change from a fast to a slow blinking LED and back again?

+	cmd[3] = 0x30 + err_led->mode;
+
+	return qnap_mcu_exec_with_ack(err_led->mcu, cmd, sizeof(cmd));
+}
+
+static int qnap_mcu_register_err_led(struct device *dev, struct qnap_mcu *mcu, int num)

What's num?  I should be able to answer that by the nomenclature.

+{
+	struct qnap_mcu_err_led *err_led;
+	int ret;
+
+	err_led = devm_kzalloc(dev, sizeof(*err_led), GFP_KERNEL);
+	if (!err_led)
+		return -ENOMEM;
+
+	err_led->mcu = mcu;
+	err_led->num = num;
+	err_led->mode = QNAP_MCU_ERR_LED_OFF;
+
+	snprintf(err_led->name, LED_MAX_NAME_SIZE, "hdd%d:red:status", num + 1);

scnprintf()?

+	err_led->cdev.name = err_led->name;
+
+	err_led->cdev.brightness_set_blocking = qnap_mcu_err_led_set;
+	err_led->cdev.blink_set = qnap_mcu_err_led_blink_set;
+	err_led->cdev.brightness = 0;
+	err_led->cdev.max_brightness = 1;
+
+	ret = devm_led_classdev_register(dev, &err_led->cdev);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to register hdd led %d", num);

"HDD LED"

+	return qnap_mcu_err_led_set(&err_led->cdev, 0);
+}
+
+enum qnap_mcu_usb_led_mode {
+	QNAP_MCU_USB_LED_ON = 1,
+	QNAP_MCU_USB_LED_OFF = 3,
+	QNAP_MCU_USB_LED_BLINK = 2,
+};
+
+struct qnap_mcu_usb_led {
+	struct qnap_mcu *mcu;
+	struct led_classdev cdev;
+	u8 mode;
+};
+
+static inline struct qnap_mcu_usb_led *
+		cdev_to_qnap_mcu_usb_led(struct led_classdev *led_cdev)
+{
+	return container_of(led_cdev, struct qnap_mcu_usb_led, cdev);
+}
+
+static int qnap_mcu_usb_led_set(struct led_classdev *led_cdev,
+				enum led_brightness value)
+{
+	struct qnap_mcu_usb_led *usb_led = cdev_to_qnap_mcu_usb_led(led_cdev);
+	u8 cmd[] = { 0x40, 0x43, 0 };
+
+	/*
+	 * If the led is off, turn it on. Otherwise don't disturb

"LED"

+	 * a possible set blink-mode.
+	 */
+	if (value == 0)
+		usb_led->mode = QNAP_MCU_USB_LED_OFF;
+	else if (usb_led->mode == QNAP_MCU_USB_LED_OFF)
+		usb_led->mode = QNAP_MCU_USB_LED_ON;

Same suggestions as above.

+	/* byte 3 is shared between the usb led target and setting the mode */

"Byte" for two reasons.  Firstly because it's the correct capitalisation
of Byte and secondly because it's the start of a sentence.

"USB" and "LED" throughout please.

+	cmd[2] = 0x44 | usb_led->mode;
+
+	return qnap_mcu_exec_with_ack(usb_led->mcu, cmd, sizeof(cmd));
+}
+
+static int qnap_mcu_usb_led_blink_set(struct led_classdev *led_cdev,
+				      unsigned long *delay_on,
+				      unsigned long *delay_off)
+{
+	struct qnap_mcu_usb_led *usb_led = cdev_to_qnap_mcu_usb_led(led_cdev);
+	u8 cmd[] = { 0x40, 0x43, 0 };
+
+	/* LED is off, nothing to do */
+	if (usb_led->mode == QNAP_MCU_USB_LED_OFF)
+		return 0;
+
+	*delay_on = 250;
+	*delay_off = 250;
+	usb_led->mode = QNAP_MCU_USB_LED_BLINK;
+
+	/* byte 3 is shared between the usb led target and setting the mode */
+	cmd[2] = 0x44 | usb_led->mode;
+
+	return qnap_mcu_exec_with_ack(usb_led->mcu, cmd, sizeof(cmd));
+}
+
+static int qnap_mcu_register_usb_led(struct device *dev, struct qnap_mcu *mcu)
+{
+	struct qnap_mcu_usb_led *usb_led;
+	int ret;
+
+	usb_led = devm_kzalloc(dev, sizeof(*usb_led), GFP_KERNEL);
+	if (!usb_led)
+		return -ENOMEM;
+
+	usb_led->mcu = mcu;
+	usb_led->mode = QNAP_MCU_USB_LED_OFF;
+	usb_led->cdev.name = "usb:blue:disk";
+	usb_led->cdev.brightness_set_blocking = qnap_mcu_usb_led_set;
+	usb_led->cdev.blink_set = qnap_mcu_usb_led_blink_set;
+	usb_led->cdev.brightness = 0;
+	usb_led->cdev.max_brightness = 1;
+
+	ret = devm_led_classdev_register(dev, &usb_led->cdev);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to register usb led");
+
+	return qnap_mcu_usb_led_set(&usb_led->cdev, 0);
+}
+
+static int qnap_mcu_leds_probe(struct platform_device *pdev)
+{
+	struct qnap_mcu *mcu = dev_get_drvdata(pdev->dev.parent);
+	const struct qnap_mcu_variant *variant = qnap_mcu_get_variant_data(mcu);

Grab this from platform_data.

+	int ret, i;
+
+	for (i = 0; i < variant->num_drives; i++) {

You can use:

	for (int i = 0; ..

+		ret = qnap_mcu_register_err_led(&pdev->dev, mcu, i);
+		if (ret)
+			return dev_err_probe(&pdev->dev, ret,
+					"failed to register error led %d\n", i);
+	}
+
+	if (variant->usb_led) {
+		ret = qnap_mcu_register_usb_led(&pdev->dev, mcu);
+		if (ret)
+			return dev_err_probe(&pdev->dev, ret,
+					"failed to register usb led %d\n", i);

The 'i' here looks like a copy/paste error.

+	}
+
+	return 0;
+}
+
+static struct platform_driver qnap_mcu_leds_driver = {
+	.probe = qnap_mcu_leds_probe,
+	.driver = {
+		.name = "qnap-mcu-leds",
+	},
+};
+module_platform_driver(qnap_mcu_leds_driver);
+
+MODULE_ALIAS("platform:qnap-mcu-leds");
+MODULE_AUTHOR("Heiko Stuebner [off-list ref]");
+MODULE_DESCRIPTION("QNAP MCU LEDs driver");
+MODULE_LICENSE("GPL");
-- 
2.43.0

-- 
Lee Jones [李琼斯]