fbdev: sh_mobile_hdmi: add support for E-EDID parsing

Many HDMI clients implement enhanced EDID blocks, which often contain
additional supported video modes. This patch implements parsing of such
E-EDID blocks.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 49 insertions, 11 deletions

diff --git a/drivers/video/sh_mobile_hdmi.c b/drivers/video/sh_mobile_hdmi.c
index 3b4cf987fb43..76f9fac9020f 100644
--- a/drivers/video/sh_mobile_hdmi.c
+++ b/drivers/video/sh_mobile_hdmi.c
@@ -211,6 +211,9 @@ struct sh_hdmi {
         enum hotplug_state hp_state;    /* hot-plug status */
         u8 preprogrammed_vic;           /* use a pre-programmed VIC or
                                            the external mode */
+        u8 edid_block_addr;
+        u8 edid_segment_nr;
+        u8 edid_blocks;
         struct clk *hdmi_clk;
         struct device *dev;
         struct fb_info *info;
@@ -756,7 +759,38 @@ static int sh_hdmi_read_edid(struct sh_hdmi *hdmi, unsigned long *hdmi_rate,
         printk(KERN_CONT "\n");
 #endif
 
-        fb_edid_to_monspecs(edid, &hdmi->monspec);
+        if (!hdmi->edid_blocks) {
+                fb_edid_to_monspecs(edid, &hdmi->monspec);
+                hdmi->edid_blocks = edid[126] + 1;
+
+                dev_dbg(hdmi->dev, "%d main modes, %d extension blocks\n",
+                        hdmi->monspec.modedb_len, hdmi->edid_blocks - 1);
+        } else {
+                dev_dbg(hdmi->dev, "Extension %u detected, DTD start %u\n",
+                        edid[0], edid[2]);
+                fb_edid_add_monspecs(edid, &hdmi->monspec);
+        }
+
+        if (hdmi->edid_blocks > hdmi->edid_segment_nr * 2 +
+            (hdmi->edid_block_addr >> 7) + 1) {
+                /* More blocks to read */
+                if (hdmi->edid_block_addr) {
+                        hdmi->edid_block_addr = 0;
+                        hdmi->edid_segment_nr++;
+                } else {
+                        hdmi->edid_block_addr = 0x80;
+                }
+                /* Set EDID word address  */
+                hdmi_write(hdmi, hdmi->edid_block_addr, HDMI_EDID_WORD_ADDRESS);
+                /* Enable EDID interrupt */
+                hdmi_write(hdmi, 0xC6, HDMI_INTERRUPT_MASK_1);
+                /* Set EDID segment pointer - starts reading EDID */
+                hdmi_write(hdmi, hdmi->edid_segment_nr, HDMI_EDID_SEGMENT_POINTER);
+                return -EAGAIN;
+        }
+
+        /* All E-EDID blocks ready */
+        dev_dbg(hdmi->dev, "%d main and extended modes\n", hdmi->monspec.modedb_len);
 
         fb_get_options("sh_mobile_lcdc", &forced);
         if (forced && *forced) {
@@ -903,32 +937,34 @@ static irqreturn_t sh_hdmi_hotplug(int irq, void *dev_id)
                 /* Check, if hot plug & MSENS pin status are both high */
                 if ((msens & 0xC0) == 0xC0) {
                         /* Display plug in */
+                        hdmi->edid_segment_nr = 0;
+                        hdmi->edid_block_addr = 0;
+                        hdmi->edid_blocks = 0;
                         hdmi->hp_state = HDMI_HOTPLUG_CONNECTED;
 
                         /* Set EDID word address  */
                         hdmi_write(hdmi, 0x00, HDMI_EDID_WORD_ADDRESS);
-                        /* Set EDID segment pointer */
-                        hdmi_write(hdmi, 0x00, HDMI_EDID_SEGMENT_POINTER);
                         /* Enable EDID interrupt */
                         hdmi_write(hdmi, 0xC6, HDMI_INTERRUPT_MASK_1);
+                        /* Set EDID segment pointer - starts reading EDID */
+                        hdmi_write(hdmi, 0x00, HDMI_EDID_SEGMENT_POINTER);
                 } else if (!(status1 & 0x80)) {
                         /* Display unplug, beware multiple interrupts */
-                        if (hdmi->hp_state != HDMI_HOTPLUG_DISCONNECTED)
+                        if (hdmi->hp_state != HDMI_HOTPLUG_DISCONNECTED) {
+                                hdmi->hp_state = HDMI_HOTPLUG_DISCONNECTED;
                                 schedule_delayed_work(&hdmi->edid_work, 0);
-
-                        hdmi->hp_state = HDMI_HOTPLUG_DISCONNECTED;
+                        }
                         /* display_off will switch back to mode_a */
                 }
         } else if (status1 & 2) {
                 /* EDID error interrupt: retry */
                 /* Set EDID word address  */
-                hdmi_write(hdmi, 0x00, HDMI_EDID_WORD_ADDRESS);
+                hdmi_write(hdmi, hdmi->edid_block_addr, HDMI_EDID_WORD_ADDRESS);
                 /* Set EDID segment pointer */
-                hdmi_write(hdmi, 0x00, HDMI_EDID_SEGMENT_POINTER);
+                hdmi_write(hdmi, hdmi->edid_segment_nr, HDMI_EDID_SEGMENT_POINTER);
         } else if (status1 & 4) {
                 /* Disable EDID interrupt */
                 hdmi_write(hdmi, 0xC0, HDMI_INTERRUPT_MASK_1);
-                hdmi->hp_state = HDMI_HOTPLUG_EDID_DONE;
                 schedule_delayed_work(&hdmi->edid_work, msecs_to_jiffies(10));
         }
 
@@ -1056,7 +1092,7 @@ static void sh_hdmi_edid_work_fn(struct work_struct *work)
 
         mutex_lock(&hdmi->mutex);
 
-        if (hdmi->hp_state == HDMI_HOTPLUG_EDID_DONE) {
+        if (hdmi->hp_state == HDMI_HOTPLUG_CONNECTED) {
                 unsigned long parent_rate = 0, hdmi_rate;
 
                 /* A device has been plugged in */
@@ -1066,6 +1102,8 @@ static void sh_hdmi_edid_work_fn(struct work_struct *work)
                 if (ret < 0)
                         goto out;
 
+                hdmi->hp_state = HDMI_HOTPLUG_EDID_DONE;
+
                 /* Reconfigure the clock */
                 ret = sh_hdmi_clk_configure(hdmi, hdmi_rate, parent_rate);
                 if (ret < 0)
@@ -1119,7 +1157,7 @@ static void sh_hdmi_edid_work_fn(struct work_struct *work)
         }
 
 out:
-        if (ret < 0)
+        if (ret < 0 && ret != -EAGAIN)
                 hdmi->hp_state = HDMI_HOTPLUG_DISCONNECTED;
         mutex_unlock(&hdmi->mutex);