GFX: Initialize the SDVO device based on the valid slave address

When the slave address is found for the SDVO port, the SDVO device will
be initialzied.
When the slave address is not found for the SDVO port, it will return
the slave address by using the following flowchart:
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@intel.com>

1 files changed, 68 insertions, 4 deletions

diff --git a/src/i830_sdvo.c b/src/i830_sdvo.c
index cfba482c..acfe5999 100644
--- a/src/i830_sdvo.c
+++ b/src/i830_sdvo.c
@@ -1038,7 +1038,6 @@ i830_sdvo_mode_fixup(xf86OutputPtr output, DisplayModePtr mode,
 	/* Set the input timing to the screen. Assume always input 0. */
 	i830_sdvo_set_target_input(output, TRUE, FALSE);
 
-
 	success = i830_sdvo_create_preferred_input_timing(output,
 							  mode->Clock / 10,
 							  mode->HDisplay,
@@ -2135,7 +2134,70 @@ i830_sdvo_select_ddc_bus(struct i830_sdvo_priv *dev_priv)
     /* Corresponds to SDVO_CONTROL_BUS_DDCx */
     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)
 {
@@ -2145,6 +2207,10 @@ i830_sdvo_init(ScrnInfoPtr pScrn, int output_device)
     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)
@@ -2180,14 +2246,12 @@ i830_sdvo_init(ScrnInfoPtr pScrn, int output_device)
 	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;