[PATCH] drm/exynos: set the active aspect ratio as per mode

[Shirish S]

now that the drm_display_mode also provides aspect
ratio for all resolutions, this patch adds its usage
to set the active aspect ratio of AVI info frame
packets as per CEA-861-D standard's Table 9.

This is also needed to abide by the 7-27
compliance test of HDMI.

Signed-off-by: Shirish S <s.shirish at samsung.com>
---
 drivers/gpu/drm/exynos/exynos_hdmi.c |   33 +++++++++++++++++++++++++++------
 1 file changed, 27 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c 
b/drivers/gpu/drm/exynos/exynos_hdmi.c
index c021ddc..8aca52a 100644
--- a/drivers/gpu/drm/exynos/exynos_hdmi.c
+++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
@@ -53,8 +53,6 @@
 /* AVI header and aspect ratio */
 #define HDMI_AVI_VERSION               0x02
 #define HDMI_AVI_LENGTH                0x0D
-#define AVI_PIC_ASPECT_RATIO_16_9      (2 << 4)
-#define AVI_SAME_AS_PIC_ASPECT_RATIO   8

 /* AUI header info */
 #define HDMI_AUI_VERSION       0x01
@@ -65,6 +63,12 @@ enum hdmi_type {
        HDMI_TYPE14,
 };

+enum active_aspect_ratio {
+       AVI_SAME_AS_PIC_ASPECT_RATIO = 8,
+       AVI_4_3_Center_RATIO,
+       AVI_16_9_Center_RATIO,
+};
+
 struct hdmi_resources {
        struct clk                      *hdmi;
        struct clk                      *sclk_hdmi;
@@ -162,6 +166,7 @@ struct hdmi_v14_conf {
 struct hdmi_conf_regs {
        int pixel_clock;
        int cea_video_id;
+       enum hdmi_picture_aspect aspect_ratio;
        union {
                struct hdmi_v13_conf v13_conf;
                struct hdmi_v14_conf v14_conf;
@@ -668,7 +673,6 @@ static void hdmi_reg_infoframe(struct hdmi_context *hdata,
 {
        u32 hdr_sum;
        u8 chksum;
-       u32 aspect_ratio;
        u32 mod;
        u32 vic;

@@ -697,10 +701,25 @@ static void hdmi_reg_infoframe(struct hdmi_context *hdata,
                        AVI_ACTIVE_FORMAT_VALID |
                        AVI_UNDERSCANNED_DISPLAY_VALID);

-               aspect_ratio = AVI_PIC_ASPECT_RATIO_16_9;
-
-               hdmi_reg_writeb(hdata, HDMI_AVI_BYTE(2), aspect_ratio |
+               /*
+                * Set the aspect ratio as per the mode, mentioned in
+                * Table 9 AVI InfoFrame Data Byte 2 of CEA-861-D Standard
+                */
+               switch (hdata->mode_conf.aspect_ratio) {
+               case HDMI_PICTURE_ASPECT_4_3:
+                       hdmi_reg_writeb(hdata, HDMI_AVI_BYTE(2), aspect_ratio |
+                               AVI_4_3_Center_RATIO);
+                       break;
+               case HDMI_PICTURE_ASPECT_16_9:
+                       hdmi_reg_writeb(hdata, HDMI_AVI_BYTE(2), aspect_ratio |
+                               AVI_16_9_Center_RATIO);
+                       break;
+               case HDMI_PICTURE_ASPECT_NONE:
+               default:
+                       hdmi_reg_writeb(hdata, HDMI_AVI_BYTE(2), aspect_ratio |
                                AVI_SAME_AS_PIC_ASPECT_RATIO);
+                       break;
+               }

                vic = hdata->mode_conf.cea_video_id;
                hdmi_reg_writeb(hdata, HDMI_AVI_BYTE(4), vic);
@@ -1421,6 +1440,7 @@ static void hdmi_v13_mode_set(struct hdmi_context *hdata,
        hdata->mode_conf.cea_video_id =
                drm_match_cea_mode((struct drm_display_mode *)m);
        hdata->mode_conf.pixel_clock = m->clock * 1000;
+       hdata->mode_conf.aspect_ratio = m->picture_aspect_ratio;

        hdmi_set_reg(core->h_blank, 2, m->htotal - m->hdisplay);
        hdmi_set_reg(core->h_v_line, 3, (m->htotal << 12) | m->vtotal);
@@ -1517,6 +1537,7 @@ static void hdmi_v14_mode_set(struct hdmi_context *hdata,
        hdata->mode_conf.cea_video_id =
                drm_match_cea_mode((struct drm_display_mode *)m);
        hdata->mode_conf.pixel_clock = m->clock * 1000;
+       hdata->mode_conf.aspect_ratio = m->picture_aspect_ratio;

        hdmi_set_reg(core->h_blank, 2, m->htotal - m->hdisplay);
        hdmi_set_reg(core->v_line, 2, m->vtotal);
-- 
1.7.10.4