linux/drivers/video
Fabio Estevam b82fe6ddd7 video: fbdev: imxfb: Provide a reset mechanism
Currently when we boot the kernel on a mx25pdk the LCDC controller
does not show the Linux logo on boot.

This problem is well explained by Sascha Hauer:

"Unfortunately this LCD controller does not have an enable bit. The
controller starts directly when the clocks are enabled. If the clocks
are enabled when the controller is not yet programmed with proper
register values then it just goes into some undefined state. What I
suspect is that the clocks already were enabled before driver probe,
presumably by the bootloader, so the controller is already in undefined
state when entering Linux. Now by dis/enabling the ipg clock you
effectively reset the controller. Since you have programmed it with
valid register values in the mean time it starts working after this
reset."

So do as suggested and force a reset of the LCDC hardware by
enabling and disabling the IPG clock.

With this change the Linux logo can be seen on boot on a mx25pdk.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
2016-01-29 14:20:16 +02:00
..
backlight backlight: pwm_bl: Free PWM requested by legacy API on error path 2016-01-11 10:45:24 +00:00
console fbcon: initialize blink interval before calling fb_set_par 2015-10-17 22:00:39 -07:00
fbdev video: fbdev: imxfb: Provide a reset mechanism 2016-01-29 14:20:16 +02:00
logo video/logo: prevent use of logos after they have been freed 2014-12-29 10:06:55 +02:00
display_timing.c
hdmi.c [media] hdmi: rename HDMI_AUDIO_CODING_TYPE_EXT_STREAM to _EXT_CT 2015-01-27 10:19:12 -02:00
Kconfig drm: Remove two-level menu in Kconfig 2015-08-07 19:06:37 +02:00
Makefile
of_display_timing.c video: of: fix memory leak 2015-10-07 14:13:59 +03:00
of_videomode.c video: Fix possible leak in of_get_videomode() 2015-08-10 15:11:12 +03:00
vgastate.c fbdev: vgastate: remove trailing whitespaces 2015-01-13 12:53:25 +02:00
videomode.c