Re: [PATCH v2 3/7] leds: add driver for LEDs from qnap-mcu devices

From: Florian Eckert
Date: Mon Jul 29 2024 - 02:41:09 EST

Hello Heiko,

diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index effdfc6f1e951..27eb6cd827610 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -77,6 +77,7 @@ obj-$(CONFIG_LEDS_PCA995X) += leds-pca995x.o
obj-$(CONFIG_LEDS_PM8058) += leds-pm8058.o
obj-$(CONFIG_LEDS_POWERNV) += leds-powernv.o
obj-$(CONFIG_LEDS_PWM) += leds-pwm.o
+obj-$(CONFIG_LEDS_QNAP_MCU) += leds-qnap-mcu.o
obj-$(CONFIG_LEDS_REGULATOR) += leds-regulator.o
obj-$(CONFIG_LEDS_SC27XX_BLTC) += leds-sc27xx-bltc.o
obj-$(CONFIG_LEDS_SUN50I_A100) += leds-sun50i-a100.o
diff --git a/drivers/leds/leds-qnap-mcu.c b/drivers/leds/leds-qnap-mcu.c
new file mode 100644
index 0000000000000..e3244923759d2
--- /dev/null
+++ b/drivers/leds/leds-qnap-mcu.c
@@ -0,0 +1,247 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/*
+ * Driver for LEDs found on QNAP MCU devices
+ *
+ * Copyright (C) 2024 Heiko Stuebner <heiko@xxxxxxxxx>
+ */
+
+#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;
+ 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)
+{
+ struct qnap_mcu_err_led *err_led = cdev_to_qnap_mcu_err_led(led_cdev);
+ u8 cmd[] = {
+ [0] = 0x40,
+ [1] = 0x52,
+ [2] = 0x30 + err_led->num,
+ [3] = 0x30
+ };
+
+ /*
+ * If the led is off, turn it on. Otherwise don't disturb
+ * a possible set blink-mode.
+ */
+ 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;
+
+ 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[] = {
+ [0] = 0x40,
+ [1] = 0x52,
+ [2] = 0x30 + err_led->num,
+ [3] = 0x30
+ };
+
+ /* LED is off, nothing to do */
+ if (err_led->mode == QNAP_MCU_ERR_LED_OFF)
+ return 0;
+
+ if (*delay_on < 500) {
+ *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;
+ }
+
+ 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)
+{
+ struct qnap_mcu_err_led *err_led;
+ char tmp_buf[LED_MAX_NAME_SIZE];
+ 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(tmp_buf, LED_MAX_NAME_SIZE, "hdd%d:red:status", num + 1);
+ err_led->cdev.name = tmp_buf;

Should not the memory have to be allocated here via 'kzalloc' for 'err_led->cdev.name'?
After leaving the function, tmp_buf is no longer on the stack?


+
+ 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);
+
+ 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[] = {
+ [0] = 0x40,
+ [1] = 0x43,
+ [2] = 0
+ };
+
+ /*
+ * If the led is off, turn it on. Otherwise don't disturb
+ * 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;
+
+ /* 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_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[] = {
+ [0] = 0x40,
+ [1] = 0x43,
+ [2] = 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);
+ int ret, i;
+
+ for (i = 0; i < variant->num_drives; i++) {
+ 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);
+ }
+
+ 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 <heiko@xxxxxxxxx>");
+MODULE_DESCRIPTION("QNAP MCU LEDs driver");
+MODULE_LICENSE("GPL");