Commit 2c1fb9d8 authored by Claudiu Beznea's avatar Claudiu Beznea Committed by Sam Ravnborg

drm: atmel-hlcdc: enable clock before configuring timing engine

Changing pixel clock source without having this clock source enabled
will block the timing engine and the next operations after (in this case
setting ATMEL_HLCDC_CFG(5) settings in atmel_hlcdc_crtc_mode_set_nofb()
will fail). It is recomended (although in datasheet this is not present)
to actually enabled pixel clock source before doing any changes on timing
enginge (only SAM9X60 datasheet specifies that the peripheral clock and
pixel clock must be enabled before using LCD controller).

Fixes: 1a396789 ("drm: add Atmel HLCDC Display Controller support")
Signed-off-by: default avatarClaudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: <stable@vger.kernel.org> # v4.0+
Link: https://patchwork.freedesktop.org/patch/msgid/1576672109-22707-3-git-send-email-claudiu.beznea@microchip.com
parent 07acf4ba
......@@ -73,7 +73,11 @@ static void atmel_hlcdc_crtc_mode_set_nofb(struct drm_crtc *c)
unsigned long prate;
unsigned int mask = ATMEL_HLCDC_CLKDIV_MASK | ATMEL_HLCDC_CLKPOL;
unsigned int cfg = 0;
int div;
int div, ret;
ret = clk_prepare_enable(crtc->dc->hlcdc->sys_clk);
if (ret)
return;
vm.vfront_porch = adj->crtc_vsync_start - adj->crtc_vdisplay;
vm.vback_porch = adj->crtc_vtotal - adj->crtc_vsync_end;
......@@ -147,6 +151,8 @@ static void atmel_hlcdc_crtc_mode_set_nofb(struct drm_crtc *c)
ATMEL_HLCDC_VSPSU | ATMEL_HLCDC_VSPHO |
ATMEL_HLCDC_GUARDTIME_MASK | ATMEL_HLCDC_MODE_MASK,
cfg);
clk_disable_unprepare(crtc->dc->hlcdc->sys_clk);
}
static enum drm_mode_status
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment