1 files changed, 31 insertions, 7 deletions

diff --git a/drivers/gpu/drm/ast/ast_dp501.c b/drivers/gpu/drm/ast/ast_dp501.c
index 5da4b62285fa..76f07f38b941 100644
--- a/drivers/gpu/drm/ast/ast_dp501.c
+++ b/drivers/gpu/drm/ast/ast_dp501.c
@@ -379,11 +379,39 @@ static bool ast_init_dvo(struct drm_device *dev)
         return true;
 }
 
+
+static void ast_init_analog(struct drm_device *dev)
+{
+        struct ast_private *ast = dev->dev_private;
+        u32 data;
+
+        /*
+         * Set DAC source to VGA mode in SCU2C via the P2A
+         * bridge. First configure the P2U to target the SCU
+         * in case it isn't at this stage.
+         */
+        ast_write32(ast, 0xf004, 0x1e6e0000);
+        ast_write32(ast, 0xf000, 0x1);
+
+        /* Then unlock the SCU with the magic password */
+        ast_write32(ast, 0x12000, 0x1688a8a8);
+        ast_write32(ast, 0x12000, 0x1688a8a8);
+        ast_write32(ast, 0x12000, 0x1688a8a8);
+
+        /* Finally, clear bits [17:16] of SCU2c */
+        data = ast_read32(ast, 0x1202c);
+        data &= 0xfffcffff;
+        ast_write32(ast, 0, data);
+
+        /* Disable DVO */
+        ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xa3, 0xcf, 0x00);
+}
+
 void ast_init_3rdtx(struct drm_device *dev)
 {
         struct ast_private *ast = dev->dev_private;
         u8 jreg;
-        u32 data;
+
         if (ast->chip == AST2300 || ast->chip == AST2400) {
                 jreg = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xd1, 0xff);
                 switch (jreg & 0x0e) {
@@ -399,12 +427,8 @@ void ast_init_3rdtx(struct drm_device *dev)
                 default:
                         if (ast->tx_chip_type == AST_TX_SIL164)
                                 ast_init_dvo(dev);
-                        else {
-                                ast_write32(ast, 0x12000, 0x1688a8a8);
-                                data = ast_read32(ast, 0x1202c);
-                                data &= 0xfffcffff;
-                                ast_write32(ast, 0, data);
-                        }
+                        else
+                                ast_init_analog(dev);
                 }
         }
 }