drm/ast: astdp: Only test HDP state in ast_astdp_is_connected()

The overall control flow of the driver ensures that it never reads
EDID or sets display state on unconnected outputs. Therefore remove
all tests for Hot Plug Detection from these helpers. Also rename
the register constants.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240717143319.104012-4-tzimmermann@suse.de

drivers/gpu/drm/ast/ast_dp.c

@@ -9,7 +9,7 @@
 
 bool ast_astdp_is_connected(struct ast_device *ast)
 {
-	if (!ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xDF, ASTDP_HPD))
+	if (!ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xDF, AST_IO_VGACRDF_HPD))
 		return false;
 	if (!ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xDC, ASTDP_LINK_SUCCESS))
 		return false;
@@ -23,11 +23,9 @@ int ast_astdp_read_edid(struct drm_device *dev, u8 *ediddata)
 
 	/*
 	 * CRDC[b0]: DP link success
-	 * CRDF[b0]: DP HPD
 	 * CRE5[b0]: Host reading EDID process is done
 	 */
 	if (!(ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xDC, ASTDP_LINK_SUCCESS) &&
-		ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xDF, ASTDP_HPD) &&
 		ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xE5,
 								ASTDP_HOST_EDID_READ_DONE_MASK))) {
 		goto err_astdp_edid_not_ready;
@@ -61,8 +59,7 @@ int ast_astdp_read_edid(struct drm_device *dev, u8 *ediddata)
 			mdelay(j+1);
 
 			if (!(ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xDC,
-							ASTDP_LINK_SUCCESS) &&
-				ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xDF, ASTDP_HPD))) {
+							ASTDP_LINK_SUCCESS))) {
 				goto err_astdp_jump_out_loop_of_edid;
 			}
 
@@ -111,8 +108,6 @@ int ast_astdp_read_edid(struct drm_device *dev, u8 *ediddata)
 err_astdp_edid_not_ready:
 	if (!(ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xDC, ASTDP_LINK_SUCCESS)))
 		return (~0xDC + 1);
-	if (!(ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xDF, ASTDP_HPD)))
-		return (~0xDF + 1);
 	if (!(ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xE5, ASTDP_HOST_EDID_READ_DONE_MASK)))
 		return (~0xE5 + 1);
 
@@ -175,8 +170,7 @@ void ast_dp_set_on_off(struct drm_device *dev, bool on)
 	ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xE3, (u8) ~AST_DP_VIDEO_ENABLE, on);
 
 	// If DP plug in and link successful then check video on / off status
-	if (ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xDC, ASTDP_LINK_SUCCESS) &&
-		ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xDF, ASTDP_HPD)) {
+	if (ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xDC, ASTDP_LINK_SUCCESS)) {
 		video_on_off <<= 4;
 		while (ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xDF,
 						ASTDP_MIRROR_VIDEO_ENABLE) != video_on_off) {

drivers/gpu/drm/ast/ast_reg.h

@@ -38,6 +38,7 @@
 #define AST_IO_VGACRCB_HWC_ENABLED	BIT(1)
 
 #define AST_IO_VGACRD1_MCU_FW_EXECUTING	BIT(5)
+#define AST_IO_VGACRDF_HPD		BIT(0)
 
 #define AST_IO_VGAIR1_R			(0x5A)
 #define AST_IO_VGAIR1_VREFRESH		BIT(3)
@@ -70,11 +71,9 @@
 
 /*
  * CRDC[b0]: DP link success
- * CRDF[b0]: DP HPD
  * CRE5[b0]: Host reading EDID process is done
  */
 #define ASTDP_LINK_SUCCESS		BIT(0)
-#define ASTDP_HPD			BIT(0)
 #define ASTDP_HOST_EDID_READ_DONE	BIT(0)
 #define ASTDP_HOST_EDID_READ_DONE_MASK	GENMASK(0, 0)