linux/drivers/gpu/drm/atmel-hlcdc
Peter Rosin 319711f982 drm/atmel-hlcdc: prefer a higher rate clock as pixel-clock base
If the divider used to get the pixel-clock is small, the granularity
of the frequencies possible for the pixel-clock is quite coarse. E.g.
requesting a pixel-clock of 65MHz with a sys_clk of 132MHz results
in the divider being set to 3 ending up with 44MHz.

By preferring the doubled sys_clk as base, the divider instead ends
up as 5 yielding a pixel-clock of 52.8Mhz, which is a definite
improvement.

While at it, clamp the divider so that it does not overflow in case
it gets big.

Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180824092458.13165-2-peda@axentia.se
2018-08-27 21:12:16 +02:00
..
atmel_hlcdc_crtc.c drm/atmel-hlcdc: prefer a higher rate clock as pixel-clock base 2018-08-27 21:12:16 +02:00
atmel_hlcdc_dc.c drm/atmel-hlcdc: Stop using plane->fb 2018-05-25 21:21:39 +03:00
atmel_hlcdc_dc.h drm/atmel-hclcdc: Convert to the new generic alpha property 2018-04-16 21:20:40 +02:00
atmel_hlcdc_output.c Merge tag 'drm-misc-next-2017-06-15' of git://anongit.freedesktop.org/git/drm-misc into drm-next 2017-06-16 09:33:43 +10:00
atmel_hlcdc_plane.c drm: atmel-hlcdc: Use __drm_atomic_helper_plane_reset instead of copying the logic 2018-08-06 11:41:49 +01:00
Kconfig drm/atmel-hlcdc: make fbdev support really optional 2016-07-15 10:28:33 -04:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00