Subject: GFX: Add a function that find the correct slave addrss for one SDVO port

Use the info parsed in general definition block to find the correct
slave address for one SDVO port

---
 src/i830_bios.c |   30 ++++++++++++++++++++++++++++++
 src/i830_sdvo.h |    2 ++
 2 files changed, 32 insertions(+)

Index: xf86-video-intel/src/i830_bios.c
===================================================================
--- xf86-video-intel.orig/src/i830_bios.c	2009-05-26 12:58:47.000000000 +0800
+++ xf86-video-intel/src/i830_bios.c	2009-05-26 13:00:58.000000000 +0800
@@ -350,3 +350,33 @@
 
     return 0;
 }
+/**
+ * find_sdvo_slave - find the slave address according to the dvo port
+ *
+ * The mappings between the DVO port and slave address are parsed from
+ * the child device array contained in general definition block.
+ *
+ * Returns 0 on success, and the slave_addr is also returned
+ * nonzero on failure.
+ */
+int find_sdvo_slave(int output_device, uint8_t *slave_addr)
+{
+	uint8_t dvo_port = 0;
+	uint8_t temp_slave_addr;
+	struct sdvo_device_mapping *p_mapping;
+
+	if (output_device == SDVOB)
+		dvo_port = DEVICE_PORT_DVOB;
+	else
+		dvo_port = DEVICE_PORT_DVOC;
+	p_mapping = &sdvo_mappings[dvo_port - 1];
+	temp_slave_addr = p_mapping->slave_addr;
+	if (!temp_slave_addr) {
+		/* No slave address , return failure.*/
+		return 1;
+	}
+	/* get the correct slave address */
+	*slave_addr = temp_slave_addr;
+
+	return 0;
+}
Index: xf86-video-intel/src/i830_sdvo.h
===================================================================
--- xf86-video-intel.orig/src/i830_sdvo.h	2009-05-26 12:59:13.000000000 +0800
+++ xf86-video-intel/src/i830_sdvo.h	2009-05-26 13:02:44.000000000 +0800
@@ -27,3 +27,5 @@
 
 Bool
 i830_sdvo_init(ScrnInfoPtr pScrn, int output_device);
+
+int find_sdvo_slave(int output_device, uint8_t *slave_addr);