Re: [PATCH net-next + leds v2 2/7] leds: add generic API for LEDs that can be controlled by hardware

Hi!

Many an ethernet PHY (and other chips) supports various HW control modes
for LEDs connected directly to them.

I guess this should be

"Many ethernet PHYs (and other chips) support various HW control modes
for LEDs connected directly to them."

This API registers a new private LED trigger called dev-hw-mode. When
this trigger is enabled for a LED, the various HW control modes which
are supported by the device for given LED can be get/set via hw_mode
sysfs file.

Signed-off-by: Marek Behún <redacted>
---
 .../sysfs-class-led-trigger-dev-hw-mode       |   8 +
 drivers/leds/Kconfig                          |  10 +

I guess this should live in drivers/leds/trigger/ledtrig-hw.c . I'd
call the trigger just "hw"...

+Contact:	Marek Behún [off-list ref]
+		linux-leds@vger.kernel.org
+Description:	(W) Set the HW control mode of this LED. The various available HW control modes
+		    are specific per device to which the LED is connected to and per LED itself.
+		(R) Show the available HW control modes and the currently selected one.

80 columns :-) (and please fix that globally, at least at places where
it is easy, like comments).

+	return 0;
+err_free:
+	devm_kfree(dev, led);
+	return ret;
+}

No need for explicit free with devm_ infrastructure?

+	cur_mode = led->ops->led_get_hw_mode(dev->parent, led);
+
+	for (mode = led->ops->led_iter_hw_mode(dev->parent, led, &iter);
+	     mode;
+	     mode = led->ops->led_iter_hw_mode(dev->parent, led, &iter)) {
+		bool sel;
+
+		sel = cur_mode && !strcmp(mode, cur_mode);
+
+		len += scnprintf(buf + len, PAGE_SIZE - len, "%s%s%s ", sel ? "[" : "", mode,
+				 sel ? "]" : "");
+	}
+
+	if (buf[len - 1] == ' ')
+		buf[len - 1] = '\n';

Can this ever be false? Are you accessing buf[-1] in such case?

+int of_register_hw_controlled_leds(struct device *dev, const char *devicename,
+				   const struct hw_controlled_led_ops *ops);
+int hw_controlled_led_brightness_set(struct led_classdev *cdev, enum led_brightness brightness);
+

Could we do something like hw_controlled_led -> hw_led to keep
verbosity down and line lengths reasonable? Or hwc_led?

+extern struct led_hw_trigger_type hw_control_led_trig_type;
+extern struct led_trigger hw_control_led_trig;
+
+#else /* !IS_ENABLED(CONFIG_LEDS_HW_CONTROLLED) */

CONFIG_LEDS_HWC? Or maybe CONFIG_LEDTRIG_HW?

Best regards,
									Pavel

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