Re: [PATCH/RFC v10 08/19] leds: Add support for max77693 mfd flash cell

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Hi Pavel,

Thanks for the review.

On 01/09/2015 07:46 PM, Pavel Machek wrote:
On Fri 2015-01-09 16:22:58, Jacek Anaszewski wrote:
This patch adds led-flash support to Maxim max77693 chipset.
A device can be exposed to user space through LED subsystem
sysfs interface. Device supports up to two leds which can
work in flash and torch mode. The leds can be triggered
externally or by software.


+struct max77693_sub_led {
+	/* related FLED output identifier */

->flash LED, about 4x.

+/* split composite current @i into two @iout according to @imax weights */
+static void __max77693_calc_iout(u32 iout[2], u32 i, u32 imax[2])
+{
+	u64 t = i;
+
+	t *= imax[1];
+	do_div(t, imax[0] + imax[1]);
+
+	iout[1] = (u32)t / FLASH_IOUT_STEP * FLASH_IOUT_STEP;
+	iout[0] = i - iout[1];
+}

Is 64-bit arithmetics neccessary here? Could we do the FLASH_IOUT_STEP
divisons before t *=, so that 64-bit division is not neccessary?

It is required. All these operations allow for splitting the composite
current into both outputs according to weights given in the imax array.

+static int max77693_led_flash_strobe_get(
+				struct led_classdev_flash *fled_cdev,
+				bool *state)
+{
+	struct max77693_sub_led *sub_led = flcdev_to_sub_led(fled_cdev);
+	struct max77693_led_device *led = sub_led_to_led(sub_led);
+	int ret;
+
+	if (!state)
+		return -EINVAL;
+
+	mutex_lock(&led->lock);
+
+	ret = max77693_strobe_status_get(led, state);
+
+	*state = !!(*state && (led->strobing_sub_led_id == sub_led->fled_id));
+
+
+	mutex_unlock(&led->lock);
+
+	return ret;
+}

Maybe remove some empty lines?


Of course.

--
Best Regards,
Jacek Anaszewski
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