[Intel-gfx] [PATCH 3/3] Initialize the SDVO device based on the sdvo info parsed from VBT

[yakui_zhao]

When the slave address is found for the SDVO port, the slave address will
use to initialize the SDVO device.
When the slave address is not found for the SDVO port, it will use the 
the slave address returned by using the following flowchart to initialize
the SDVO device.
a. If the SDVO device info is found for another SDVO port, it will return
the slave address that is not used. For example: if 0x70 is used, then 0x72
is returned.
b. If no SDVO device info is found for another SDVO port, it will return
0x70 for SDVOB and 0x72 for SDVOC.

http://bugs.freedesktop.org/show_bug.cgi?id=20429

Signed-off-by: Zhao Yakui <yakui.zhao at intel.com>
---
 src/i830_sdvo.c |   73 +++++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 70 insertions(+), 3 deletions(-)

Index: xf86-video-intel/src/i830_sdvo.c
===================================================================
--- xf86-video-intel.orig/src/i830_sdvo.c	2009-05-27 14:41:02.000000000 +0800
+++ xf86-video-intel/src/i830_sdvo.c	2009-05-31 13:47:33.000000000 +0800
@@ -2105,6 +2105,71 @@
     dev_priv->ddc_bus = 1 << num_bits;
 }
 
+/**
+ * find the slave address for the given SDVO port based on the info
+ * parsed in general definition blocks
+ * If the slave address is found in the SDVO device info parsed from
+ * VBT,it will be returned. Otherwise it will return the slave address
+ * by the following steps.
+ * and 0x72 for SDVOC port.
+ * a. If one SDVO device info is found in another DVO port, it will return
+ * the slave address that is not used. For example: if 0x70 is used,
+ * then 0x72 is returned.
+ * b. If no SDVO device info is found in another DVO port, it will return
+ * 0x70 for SDVOB and 0x72 for SDVOC port.
+ */
+static
+void i830_find_sdvo_slave(ScrnInfoPtr pScrn, int output_device,
+			  uint8_t *slave_addr)
+{
+    uint8_t temp_slave_addr;
+    I830Ptr pI830 = I830PTR(pScrn);
+    uint8_t dvo_port, dvo2_port;
+    struct sdvo_device_mapping *p_mapping;
+
+    if (output_device == SDVOB) {
+	/* DEVICE_PORT_DVOB */
+	dvo_port = 0;
+	dvo2_port = 1;
+    }
+    else {
+	/* DEVICE_POTR_DVOC */
+	dvo_port = 1;
+	dvo2_port = 0;
+    }
+
+    p_mapping = &(pI830->sdvo_mappings[dvo_port]);
+    temp_slave_addr = p_mapping->slave_addr;
+    if (temp_slave_addr) {
+	/* slave address is found . return it */
+	*slave_addr = temp_slave_addr;
+	return ;
+    }
+    /* Check whether the SDVO device info is found in another dvo port */
+    p_mapping = &(pI830->sdvo_mappings[dvo2_port]);
+    temp_slave_addr = p_mapping->slave_addr;
+    if (!temp_slave_addr) {
+        /* no SDVO device is found in another DVO port */
+	/* it will return 0x70 for SDVOB and 0x72 for SDVOC */
+	if (output_device == SDVOB)
+		temp_slave_addr = 0x70;
+	else
+		temp_slave_addr = 0x72;
+	*slave_addr = temp_slave_addr;
+	return ;
+    }
+    /* return the slave address that is not used.
+     * If the 0x70 is used, then 0x72 is returned.
+     * If the 0x72 is used, then 0x70 is returned.
+     */
+    if (temp_slave_addr == 0x70)
+	temp_slave_addr = 0x72;
+    else
+	temp_slave_addr = 0x70;
+
+    *slave_addr = temp_slave_addr;
+    return ;
+}
 
 Bool
 i830_sdvo_init(ScrnInfoPtr pScrn, int output_device)
@@ -2115,6 +2180,10 @@
     int			    i;
     unsigned char	    ch[0x40];
     I2CBusPtr		    i2cbus = NULL, ddcbus;
+    uint8_t slave_addr;
+
+    slave_addr = 0;
+    i830_find_sdvo_slave(pScrn, output_device, &slave_addr);
 
     output = xf86OutputCreate (pScrn, &i830_sdvo_output_funcs,NULL);
     if (!output)
@@ -2150,14 +2219,12 @@
 	xf86OutputDestroy (output);
 	return FALSE;
     }
-
     if (output_device == SDVOB) {
 	dev_priv->d.DevName = "SDVO Controller B";
-	dev_priv->d.SlaveAddr = 0x70;
     } else {
 	dev_priv->d.DevName = "SDVO Controller C";
-	dev_priv->d.SlaveAddr = 0x72;
     }
+    dev_priv->d.SlaveAddr = slave_addr;
     dev_priv->d.pI2CBus = i2cbus;
     dev_priv->d.DriverPrivate.ptr = output;
     dev_priv->output_device = output_device;