[PATCH 03/10] drm/sun4i: sun6i_mipi_dsi: Setup burst mode timings

Jagan Teki
2018-11-03T10:09:47Z

Burst mode display timings are different from convectional
video mode so update the horizontal and vertical timings.

Reference code taken from BSP
(in drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/de_dsi.c)
dsi_hsa = 0;
dsi_hbp = 0;
dsi_hact = x*dsi_pixel_bits[format]/8;
dsi_hblk = dsi_hact;
dsi_hfp = 0;
dsi_vblk = 0;

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 108 ++++++++++++++-----------
1 file changed, 60 insertions(+), 48 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index 077b57ec964c..4965b2c71e4c 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -479,59 +479,71 @@ static void sun6i_dsi_setup_timings(struct sun6i_dsi *dsi,

/* Do all timing calculations up front to allocate buffer space */

- /*
- * A sync period is composed of a blanking packet (4 bytes +
- * payload + 2 bytes) and a sync event packet (4 bytes). Its
- * minimal size is therefore 10 bytes
- */
+ if (device->mode_flags == MIPI_DSI_MODE_VIDEO_BURST) {
+ hsa = 0;
+ hbp = 0;
+ hblk = mode->hdisplay * Bpp;
+ hfp = 0;
+ vblk = 0;
+ } else {
+ /*
+ * A sync period is composed of a blanking packet (4 bytes +
+ * payload + 2 bytes) and a sync event packet (4 bytes). Its
+ * minimal size is therefore 10 bytes
+ */
#define HSA_PACKET_OVERHEAD 10
- hsa = max((unsigned int)HSA_PACKET_OVERHEAD,
- (mode->hsync_end - mode->hsync_start) * Bpp - HSA_PACKET_OVERHEAD);
-
- /*
- * The backporch is set using a blanking packet (4 bytes +
- * payload + 2 bytes). Its minimal size is therefore 6 bytes
- */
+ hsa = max((unsigned int)HSA_PACKET_OVERHEAD,
+ (mode->hsync_end - mode->hsync_start) * Bpp -
+ HSA_PACKET_OVERHEAD);
+
+ /*
+ * The backporch is set using a blanking packet (4 bytes +
+ * payload + 2 bytes). Its minimal size is therefore 6 bytes
+ */
#define HBP_PACKET_OVERHEAD 6
- hbp = max((unsigned int)HBP_PACKET_OVERHEAD,
- (mode->htotal - mode->hsync_end) * Bpp - HBP_PACKET_OVERHEAD);
-
- /*
- * hblk seems to be the line + porches length.
- * The blank is set using a blanking packet (4 bytes + 4 bytes +
- * payload + 2 bytes). So minimal size is 10 bytes
- */
+ hbp = max((unsigned int)HBP_PACKET_OVERHEAD,
+ (mode->htotal - mode->hsync_end) * Bpp -
+ HBP_PACKET_OVERHEAD);
+
+ /*
+ * hblk seems to be the line + porches length.
+ * The blank is set using a blanking packet (4 bytes + 4 bytes
+ * + payload + 2 bytes). So minimal size is 10 bytes
+ */
#define HBLK_PACKET_OVERHEAD 10
- hblk_max = (mode->htotal - (mode->hsync_end - mode->hsync_start)) * Bpp;
- hblk_max -= HBLK_PACKET_OVERHEAD;
- hblk = max_t(unsigned int, HBLK_PACKET_OVERHEAD, hblk_max);
-
- /*
- * The frontporch is set using a blanking packet (4 bytes +
- * payload + 2 bytes). Its minimal size is therefore 6 bytes
- *
- * According to BSP code, extra 10 bytes(which is hblk packet overhead)
- * is adding for hfp packet overhead since hfp depends on hblk.
- */
+ hblk_max = (mode->htotal -
+ (mode->hsync_end - mode->hsync_start)) * Bpp;
+ hblk_max -= HBLK_PACKET_OVERHEAD;
+ hblk = max_t(unsigned int, HBLK_PACKET_OVERHEAD, hblk_max);
+
+ /*
+ * The frontporch is set using a blanking packet (4 bytes +
+ * payload + 2 bytes). Its minimal size is therefore 6 bytes
+ *
+ * According to BSP code, extra 10 bytes(which is hblk packet
+ * overhead) is adding for hfp packet overhead since hfp
+ * depends on hblk.
+ */
#define HFP_PACKET_OVERHEAD 6
- hfp_pkt_overhead = (HFP_PACKET_OVERHEAD + HBLK_PACKET_OVERHEAD);
- hfp = max((unsigned int)hfp_pkt_overhead,
- (mode->hsync_start - mode->hdisplay) * Bpp -
- hfp_pkt_overhead);
-
- /*
- * The vertical blank is set using a blanking packet (4 bytes +
- * payload + 2 bytes). Its minimal size is therefore 6 bytes
- */
+ hfp_pkt_overhead = (HFP_PACKET_OVERHEAD + HBLK_PACKET_OVERHEAD);
+ hfp = max((unsigned int)hfp_pkt_overhead,
+ (mode->hsync_start - mode->hdisplay) * Bpp -
+ hfp_pkt_overhead);
+
+ /*
+ * The vertical blank is set using a blanking packet (4 bytes +
+ * payload + 2 bytes). Its minimal size is therefore 6 bytes
+ */
#define VBLK_PACKET_OVERHEAD 6
- if (device->lanes == 4) {
- int tmp;
-
- tmp = (mode->htotal * Bpp) * mode->vtotal -
- (hblk + VBLK_PACKET_OVERHEAD);
- vblk = (device->lanes - tmp % device->lanes);
- } else {
- vblk = 0;
+ if (device->lanes == 4) {
+ int tmp;
+
+ tmp = (mode->htotal * Bpp) * mode->vtotal -
+ (hblk + VBLK_PACKET_OVERHEAD);
+ vblk = (device->lanes - tmp % device->lanes);
+ } else {
+ vblk = 0;
+ }
}

/* How many bytes do we need to send all payloads? */
--
2.18.0.321.gffc6fa0e3