drm/bridge/sii8620: improve reading device capabilities function

This patch adds error checks, improves logging and constifies static array.
As a result the function is similar to mainline, except missing sink
name reporting which is not yet supported by drm core.

Change-Id: Icf7a72f0b9098f74f04e039c8c5dc5dfa3c59e17
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>

diff --git a/drivers/gpu/drm/bridge/sii8620.c b/drivers/gpu/drm/bridge/sii8620.c
index c0c87e8..f2b5ff3 100644 (file)
--- a/drivers/gpu/drm/bridge/sii8620.c
+++ b/drivers/gpu/drm/bridge/sii8620.c
@@ -104,6 +104,8 @@ static const u8 sii8620_i2c_page[] = {
        0x61, /* eCBUS-S, eCBUS-D */
 };
 
+static void sii8620_mhl_disconnected(struct sii8620 *ctx);
+
 static int sii8620_clear_error(struct sii8620 *ctx)
 {
        int ret = ctx->error;
@@ -367,31 +369,41 @@ static void sii8620_update_array(u8 *dst, u8 *src, int count)
 
 static void sii8620_mr_devcap(struct sii8620 *ctx)
 {
-       static const char *sink_str[] = {
+       static const char * const sink_str[] = {
                [SINK_NONE] = "NONE",
                [SINK_HDMI] = "HDMI",
                [SINK_DVI] = "DVI"
        };
 
        u8 dcap[MHL_DCAP_SIZE];
+       struct device *dev = ctx->dev;
+
+       sii8620_read_buf(ctx, REG_EDID_FIFO_RD_DATA, dcap, MHL_DCAP_SIZE);
+       if (ctx->error < 0)
+               return;
 
-       sii8620_read_buf(ctx, REG_EDID_FIFO_RD_DATA, dcap,
-                        MHL_DCAP_SIZE);
+       dev_info(dev, "detected dongle MHL %d.%d, ChipID %02x%02x:%02x%02x\n",
+               dcap[MHL_DCAP_MHL_VERSION] / 16, dcap[MHL_DCAP_MHL_VERSION] % 16,
+               dcap[MHL_DCAP_ADOPTER_ID_H], dcap[MHL_DCAP_ADOPTER_ID_L],
+               dcap[MHL_DCAP_DEVICE_ID_H], dcap[MHL_DCAP_DEVICE_ID_L]);
        sii8620_update_array(ctx->devcap, dcap, MHL_DCAP_SIZE);
 
        if (!(dcap[MHL_DCAP_CAT] & MHL_DCAP_CAT_SINK))
                return;
 
        sii8620_fetch_edid(ctx);
+       if (!ctx->edid) {
+               dev_err(ctx->dev, "Cannot fetch EDID\n");
+               sii8620_mhl_disconnected(ctx);
+               return;
+       }
+
        if (drm_detect_hdmi_monitor(ctx->edid))
                ctx->sink_type = SINK_HDMI;
        else
                ctx->sink_type = SINK_DVI;
 
-       dev_info(ctx->dev, "detected dongle: %s, ppixel: %d\n",
-                sink_str[ctx->sink_type],
-                !!(ctx->devcap[MHL_DCAP_VID_LINK_MODE]
-                   & MHL_DCAP_VID_LINK_PPIXEL));
+       dev_info(dev, "detected sink(type: %s)\n", sink_str[ctx->sink_type]);
        sii8620_set_upstream_edid(ctx);
        sii8620_enable_hpd(ctx);
 }