drm/i2c: adv7511: Use internal timing generator

ADV7533 provides an internal timing generator for certain modes that it
can't use the DSI clock directly.

We've observed that hdmi is more stable with the internal timing
generator, especially if there are instabilities in the dsi clock source.

The data spec recommends usage of the timing generator too. Use it all
the time.

Signed-off-by: Archit Taneja <architt@codeaurora.org>

diff --git a/drivers/gpu/drm/i2c/adv7511.c b/drivers/gpu/drm/i2c/adv7511.c
index b72e5292c1e148d76aa3598d6c93a8e5060284c3..eec5885d6e9e86fe6ae8c3bc41f19d33eff42975 100644 (file)
--- a/drivers/gpu/drm/i2c/adv7511.c
+++ b/drivers/gpu/drm/i2c/adv7511.c
@@ -39,6 +39,8 @@ struct adv7511 {
        enum drm_connector_status status;
        bool powered;
 
+       struct drm_display_mode curr_mode;
+
        unsigned int f_tmds;
 
        unsigned int current_edid_segment;
@@ -404,6 +406,45 @@ static void adv7511_set_link_config(struct adv7511 *adv7511,
        adv7511->rgb = config->input_colorspace == HDMI_COLORSPACE_RGB;
 }
 
+static void adv7511_dsi_config_tgen(struct adv7511 *adv7511)
+{
+       struct mipi_dsi_device *dsi = adv7511->dsi;
+       struct drm_display_mode *mode = &adv7511->curr_mode;
+       u8 clock_div_by_lanes[] = { 6, 4, 3 }; /* 2, 3, 4 lanes */
+       unsigned int hsw, hfp, hbp, vsw, vfp, vbp;
+
+       hsw = mode->hsync_end - mode->hsync_start;
+       hfp = mode->hsync_start - mode->hdisplay;
+       hbp = mode->htotal - mode->hsync_end;
+       vsw = mode->vsync_end - mode->vsync_start;
+       vfp = mode->vsync_start - mode->vdisplay;
+       vbp = mode->vtotal - mode->vsync_end;
+
+       /* set pixel clock divider mode */
+       regmap_write(adv7511->regmap_cec, 0x16,
+                       clock_div_by_lanes[dsi->lanes - 2] << 3);
+
+       /* horizontal porch params */
+       regmap_write(adv7511->regmap_cec, 0x28, mode->htotal >> 4);
+       regmap_write(adv7511->regmap_cec, 0x29, (mode->htotal << 4) & 0xff);
+       regmap_write(adv7511->regmap_cec, 0x2a, hsw >> 4);
+       regmap_write(adv7511->regmap_cec, 0x2b, (hsw << 4) & 0xff);
+       regmap_write(adv7511->regmap_cec, 0x2c, hfp >> 4);
+       regmap_write(adv7511->regmap_cec, 0x2d, (hfp << 4) & 0xff);
+       regmap_write(adv7511->regmap_cec, 0x2e, hbp >> 4);
+       regmap_write(adv7511->regmap_cec, 0x2f, (hbp << 4) & 0xff);
+
+       /* vertical porch params */
+       regmap_write(adv7511->regmap_cec, 0x30, mode->vtotal >> 4);
+       regmap_write(adv7511->regmap_cec, 0x31, (mode->vtotal << 4) & 0xff);
+       regmap_write(adv7511->regmap_cec, 0x32, vsw >> 4);
+       regmap_write(adv7511->regmap_cec, 0x33, (vsw << 4) & 0xff);
+       regmap_write(adv7511->regmap_cec, 0x34, vfp >> 4);
+       regmap_write(adv7511->regmap_cec, 0x35, (vfp << 4) & 0xff);
+       regmap_write(adv7511->regmap_cec, 0x36, vbp >> 4);
+       regmap_write(adv7511->regmap_cec, 0x37, (vbp << 4) & 0xff);
+}
+
 static void adv7511_dsi_receiver_dpms(struct adv7511 *adv7511)
 {
        if (adv7511->type != ADV7533)
@@ -412,16 +453,23 @@ static void adv7511_dsi_receiver_dpms(struct adv7511 *adv7511)
        if (adv7511->powered) {
                struct mipi_dsi_device *dsi = adv7511->dsi;
 
+               adv7511_dsi_config_tgen(adv7511);
+
                /* set number of dsi lanes */
                regmap_write(adv7511->regmap_cec, 0x1c, dsi->lanes << 4);
-               /* disable internal timing generator */
-               regmap_write(adv7511->regmap_cec, 0x27, 0x0b);
+
+               /* reset internal timing generator */
+               regmap_write(adv7511->regmap_cec, 0x27, 0xcb);
+               regmap_write(adv7511->regmap_cec, 0x27, 0x8b);
+               regmap_write(adv7511->regmap_cec, 0x27, 0xcb);
+
                /* enable hdmi */
                regmap_write(adv7511->regmap_cec, 0x03, 0x89);
                /* disable test mode */
                regmap_write(adv7511->regmap_cec, 0x55, 0x00);
        } else {
                regmap_write(adv7511->regmap_cec, 0x03, 0x0b);
+               regmap_write(adv7511->regmap_cec, 0x27, 0x0b);
        }
 }
 
@@ -808,6 +856,8 @@ static void adv7511_mode_set(struct adv7511 *adv7511,
        regmap_update_bits(adv7511->regmap, 0x17,
                0x60, (vsync_polarity << 6) | (hsync_polarity << 5));
 
+       drm_mode_copy(&adv7511->curr_mode, adj_mode);
+
        /*
         * TODO Test first order 4:2:2 to 4:4:4 up conversion method, which is
         * supposed to give better results.