Re: [PATCH 7/8] fbdev: ssd1307fb: Add sysfs handles to expose contrast and dim setting to userspace.

On 09/02/15 10:52, Maxime Ripard wrote:

On Sat, Feb 07, 2015 at 05:42:44PM +0100, Thomas Niederprüm wrote:

quoted

quoted

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+static struct device_attribute device_attrs[] = {
+	__ATTR(contrast, S_IRUGO|S_IWUSR, show_contrast,
store_contrast),
+	__ATTR(dim, S_IRUGO|S_IWUSR, show_dim, store_dim),
+
+};
+

I would have thought this was something accessible through the
framebuffer ioctl.

Apparently it's not, at least for the contrast, so maybe it should be
added there, instead of doing it for a single driver?

I think the contrast setting for an OLED display is much like the
backlight setting for LCD panel. Since there is also no ioctl to set
the backlight of an LCD I wonder if the contrast of an OLED should have
one.

It's too much of framebuffer interface debate for me here. Tomi?

We have backlight and contrast already in backlight-class and lcd-class
(drivers/video/backlight/backlight.c and drivers/video/backlight/lcd.c).
Are those something that could be used here instead of custom sysfs files?

 Tomi