[PATCH 08/10] drm/bridge: cdns: Separate DSI and D-PHY configuration

From: Maxime Ripard
Date: Wed Sep 05 2018 - 05:17:01 EST


The current configuration of the DSI bridge and its associated D-PHY is
intertwined. In order to ease the future conversion to the phy framework
for the D-PHY part, let's split the configuration in two.

Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxx>
---
drivers/gpu/drm/bridge/cdns-dsi.c | 87 +++++++++++++++++++++++---------
1 file changed, 64 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/bridge/cdns-dsi.c b/drivers/gpu/drm/bridge/cdns-dsi.c
index 6474e6d999b7..bb9a71ad3d91 100644
--- a/drivers/gpu/drm/bridge/cdns-dsi.c
+++ b/drivers/gpu/drm/bridge/cdns-dsi.c
@@ -545,6 +545,11 @@ bridge_to_cdns_dsi_input(struct drm_bridge *bridge)
return container_of(bridge, struct cdns_dsi_input, bridge);
}

+static unsigned int mode_to_dpi_hfp(const struct drm_display_mode *mode)
+{
+ return mode->crtc_hsync_start - mode->crtc_hdisplay;
+}
+
static int cdns_dsi_get_dphy_pll_cfg(struct cdns_dphy *dphy,
struct cdns_dphy_cfg *cfg,
unsigned int dpi_htotal,
@@ -730,14 +735,12 @@ static unsigned int dpi_to_dsi_timing(unsigned int dpi_timing,

static int cdns_dsi_mode2cfg(struct cdns_dsi *dsi,
const struct drm_display_mode *mode,
- struct cdns_dsi_cfg *dsi_cfg,
- struct cdns_dphy_cfg *dphy_cfg)
+ struct cdns_dsi_cfg *dsi_cfg)
{
- unsigned long dsi_htotal = 0, dsi_hss_hsa_hse_hbp = 0;
struct cdns_dsi_output *output = &dsi->output;
- unsigned int dsi_hfp_ext = 0, dpi_hfp, tmp;
+ unsigned int tmp;
bool sync_pulse = false;
- int bpp, nlanes, ret;
+ int bpp, nlanes;

memset(dsi_cfg, 0, sizeof(*dsi_cfg));

@@ -751,44 +754,84 @@ static int cdns_dsi_mode2cfg(struct cdns_dsi *dsi,
(sync_pulse ? mode->crtc_hsync_end : mode->crtc_hsync_start);

dsi_cfg->hbp = dpi_to_dsi_timing(tmp, bpp, DSI_HBP_FRAME_OVERHEAD);
- dsi_htotal += dsi_cfg->hbp + DSI_HBP_FRAME_OVERHEAD;
- dsi_hss_hsa_hse_hbp += dsi_cfg->hbp + DSI_HBP_FRAME_OVERHEAD;

if (sync_pulse) {
tmp = mode->crtc_hsync_end - mode->crtc_hsync_start;

dsi_cfg->hsa = dpi_to_dsi_timing(tmp, bpp,
DSI_HSA_FRAME_OVERHEAD);
- dsi_htotal += dsi_cfg->hsa + DSI_HSA_FRAME_OVERHEAD;
- dsi_hss_hsa_hse_hbp += dsi_cfg->hsa + DSI_HSA_FRAME_OVERHEAD;
}

dsi_cfg->hact = dpi_to_dsi_timing(mode->crtc_hdisplay,
bpp, 0);
- dsi_htotal += dsi_cfg->hact;
+ dsi_cfg->hfp = dpi_to_dsi_timing(mode_to_dpi_hfp(mode), bpp,
+ DSI_HFP_FRAME_OVERHEAD);
+
+ return 0;
+}

- dpi_hfp = mode->crtc_hsync_start - mode->crtc_hdisplay;
- dsi_cfg->hfp = dpi_to_dsi_timing(dpi_hfp, bpp, DSI_HFP_FRAME_OVERHEAD);
+static int cdns_dphy_validate(struct cdns_dsi *dsi,
+ struct cdns_dsi_cfg *dsi_cfg,
+ struct cdns_dphy_cfg *dphy_cfg,
+ const struct drm_display_mode *mode)
+{
+ struct cdns_dsi_output *output = &dsi->output;
+ unsigned long dsi_htotal;
+ unsigned int dsi_hfp_ext = 0;
+
+ int ret;
+
+ dsi_htotal = dsi_cfg->hbp + DSI_HBP_FRAME_OVERHEAD;
+ if (output->dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
+ dsi_htotal += dsi_cfg->hsa + DSI_HSA_FRAME_OVERHEAD;
+
+ dsi_htotal += dsi_cfg->hact;
dsi_htotal += dsi_cfg->hfp + DSI_HFP_FRAME_OVERHEAD;

ret = cdns_dsi_get_dphy_pll_cfg(dsi->dphy, dphy_cfg,
- mode->crtc_htotal, bpp,
+ mode->crtc_htotal,
+ mipi_dsi_pixel_format_to_bpp(output->dev->format),
mode->crtc_clock * 1000,
- dsi_htotal, nlanes,
+ dsi_htotal,
+ output->dev->lanes,
&dsi_hfp_ext);
if (ret)
return ret;

dsi_cfg->hfp += dsi_hfp_ext;
- dsi_htotal += dsi_hfp_ext;
- dsi_cfg->htotal = dsi_htotal;
+ dsi_cfg->htotal = dsi_htotal + dsi_hfp_ext;
+
+ return 0;
+}
+
+static int cdns_dsi_check_conf(struct cdns_dsi *dsi,
+ const struct drm_display_mode *mode,
+ struct cdns_dsi_cfg *dsi_cfg,
+ struct cdns_dphy_cfg *dphy_cfg)
+{
+ struct cdns_dsi_output *output = &dsi->output;
+ unsigned long dsi_hss_hsa_hse_hbp;
+ unsigned int nlanes = output->dev->lanes;
+ int ret;
+
+ ret = cdns_dsi_mode2cfg(dsi, mode, dsi_cfg);
+ if (ret)
+ return ret;
+
+ ret = cdns_dphy_validate(dsi, dsi_cfg, dphy_cfg, mode);
+ if (ret)
+ return ret;
+
+ dsi_hss_hsa_hse_hbp = dsi_cfg->hbp + DSI_HBP_FRAME_OVERHEAD;
+ if (output->dev->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
+ dsi_hss_hsa_hse_hbp += dsi_cfg->hsa + DSI_HSA_FRAME_OVERHEAD;

/*
* Make sure DPI(HFP) > DSI(HSS+HSA+HSE+HBP) to guarantee that the FIFO
* is empty before we start a receiving a new line on the DPI
* interface.
*/
- if ((u64)dphy_cfg->lane_bps * dpi_hfp * nlanes <
+ if ((u64)dphy_cfg->lane_bps * mode_to_dpi_hfp(mode) * nlanes <
(u64)dsi_hss_hsa_hse_hbp * mode->crtc_clock * 1000)
return -EINVAL;

@@ -819,7 +862,7 @@ cdns_dsi_bridge_mode_valid(struct drm_bridge *bridge,
struct cdns_dsi_output *output = &dsi->output;
struct cdns_dphy_cfg dphy_cfg;
struct cdns_dsi_cfg dsi_cfg;
- int bpp, nlanes, ret;
+ int bpp, ret;

/*
* VFP_DSI should be less than VFP_DPI and VFP_DSI should be at
@@ -837,11 +880,9 @@ cdns_dsi_bridge_mode_valid(struct drm_bridge *bridge,
if ((mode->hdisplay * bpp) % 32)
return MODE_H_ILLEGAL;

- nlanes = output->dev->lanes;
-
- ret = cdns_dsi_mode2cfg(dsi, mode, &dsi_cfg, &dphy_cfg);
+ ret = cdns_dsi_check_conf(dsi, mode, &dsi_cfg, &dphy_cfg);
if (ret)
- return MODE_CLOCK_RANGE;
+ return MODE_BAD;

return MODE_OK;
}
@@ -967,7 +1008,7 @@ static void cdns_dsi_bridge_enable(struct drm_bridge *bridge)
bpp = mipi_dsi_pixel_format_to_bpp(output->dev->format);
nlanes = output->dev->lanes;

- WARN_ON_ONCE(cdns_dsi_mode2cfg(dsi, mode, &dsi_cfg, &dphy_cfg));
+ WARN_ON_ONCE(cdns_dsi_check_conf(dsi, mode, &dsi_cfg, &dphy_cfg));

cdns_dsi_hs_init(dsi, &dphy_cfg);
cdns_dsi_init_link(dsi);
--
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