drm/ast: Handle known struct ast_dramstruct with helpers

Most of struct ast_dramstruct stores hardware state. Some index
values have known or special meaning. The known values are

- 0xffff - Terminal entry in the array
- 0xff00 - Delays the programming for usecs
- 0x0004 - Sets the type of DRAM

Add constants and helper macros for these cases. Also add a helper
macro for testing. Update Gen1 and Gen2+ accordingly.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20250706162816.211552-8-tzimmermann@suse.de

Author: tdz

drivers/gpu/drm/ast/ast_2000.c

@@ -38,9 +38,9 @@
 static const struct ast_dramstruct ast2000_dram_table_data[] = {
 	{ 0x0108, 0x00000000 },
 	{ 0x0120, 0x00004a21 },
-	{ 0xFF00, 0x00000043 },
+	AST_DRAMSTRUCT_UDELAY(67u),
 	{ 0x0000, 0xFFFFFFFF },
-	{ 0x0004, 0x00000089 },
+	AST_DRAMSTRUCT_INIT(DRAM_TYPE, 0x00000089),
 	{ 0x0008, 0x22331353 },
 	{ 0x000C, 0x0d07000b },
 	{ 0x0010, 0x11113333 },
@@ -49,18 +49,18 @@ static const struct ast_dramstruct ast2000_dram_table_data[] = {
 	{ 0x0024, 0x00000001 },
 	{ 0x001C, 0x00000000 },
 	{ 0x0014, 0x00000003 },
-	{ 0xFF00, 0x00000043 },
+	AST_DRAMSTRUCT_UDELAY(67u),
 	{ 0x0018, 0x00000131 },
 	{ 0x0014, 0x00000001 },
-	{ 0xFF00, 0x00000043 },
+	AST_DRAMSTRUCT_UDELAY(67u),
 	{ 0x0018, 0x00000031 },
 	{ 0x0014, 0x00000001 },
-	{ 0xFF00, 0x00000043 },
+	AST_DRAMSTRUCT_UDELAY(67u),
 	{ 0x0028, 0x1e0828f1 },
 	{ 0x0024, 0x00000003 },
 	{ 0x002C, 0x1f0f28fb },
 	{ 0x0030, 0xFFFFFE01 },
-	{ 0xFFFF, 0xFFFFFFFF }
+	AST_DRAMSTRUCT_INVALID,
 };
 
 static void ast_post_chip_2000(struct ast_device *ast)
@@ -81,8 +81,8 @@ static void ast_post_chip_2000(struct ast_device *ast)
 			;
 		} while (ast_read32(ast, 0x10100) != 0xa8);
 
-		while (dram_reg_info->index != 0xffff) {
-			if (dram_reg_info->index == 0xff00) {/* delay fn */
+		while (!AST_DRAMSTRUCT_IS(dram_reg_info, INVALID)) {
+			if (AST_DRAMSTRUCT_IS(dram_reg_info, UDELAY)) {
 				for (i = 0; i < 15; i++)
 					udelay(dram_reg_info->data);
 			} else {

drivers/gpu/drm/ast/ast_2100.c

@@ -38,11 +38,11 @@
 static const struct ast_dramstruct ast1100_dram_table_data[] = {
 	{ 0x2000, 0x1688a8a8 },
 	{ 0x2020, 0x000041f0 },
-	{ 0xFF00, 0x00000043 },
+	AST_DRAMSTRUCT_UDELAY(67u),
 	{ 0x0000, 0xfc600309 },
 	{ 0x006C, 0x00909090 },
 	{ 0x0064, 0x00050000 },
-	{ 0x0004, 0x00000585 },
+	AST_DRAMSTRUCT_INIT(DRAM_TYPE, 0x00000585),
 	{ 0x0008, 0x0011030f },
 	{ 0x0010, 0x22201724 },
 	{ 0x0018, 0x1e29011a },
@@ -68,7 +68,7 @@ static const struct ast_dramstruct ast1100_dram_table_data[] = {
 	{ 0x0078, 0x00000000 },
 	{ 0x007C, 0x00000000 },
 	{ 0x0034, 0x00000001 },
-	{ 0xFF00, 0x00000043 },
+	AST_DRAMSTRUCT_UDELAY(67u),
 	{ 0x002C, 0x00000732 },
 	{ 0x0030, 0x00000040 },
 	{ 0x0028, 0x00000005 },
@@ -85,17 +85,17 @@ static const struct ast_dramstruct ast1100_dram_table_data[] = {
 	{ 0x000C, 0x00005a21 },
 	{ 0x0034, 0x00007c03 },
 	{ 0x0120, 0x00004c41 },
-	{ 0xffff, 0xffffffff },
+	AST_DRAMSTRUCT_INVALID,
 };
 
 static const struct ast_dramstruct ast2100_dram_table_data[] = {
 	{ 0x2000, 0x1688a8a8 },
 	{ 0x2020, 0x00004120 },
-	{ 0xFF00, 0x00000043 },
+	AST_DRAMSTRUCT_UDELAY(67u),
 	{ 0x0000, 0xfc600309 },
 	{ 0x006C, 0x00909090 },
 	{ 0x0064, 0x00070000 },
-	{ 0x0004, 0x00000489 },
+	AST_DRAMSTRUCT_INIT(DRAM_TYPE, 0x00000489),
 	{ 0x0008, 0x0011030f },
 	{ 0x0010, 0x32302926 },
 	{ 0x0018, 0x274c0122 },
@@ -121,7 +121,7 @@ static const struct ast_dramstruct ast2100_dram_table_data[] = {
 	{ 0x0078, 0x00000000 },
 	{ 0x007C, 0x00000000 },
 	{ 0x0034, 0x00000001 },
-	{ 0xFF00, 0x00000043 },
+	AST_DRAMSTRUCT_UDELAY(67u),
 	{ 0x002C, 0x00000942 },
 	{ 0x0030, 0x00000040 },
 	{ 0x0028, 0x00000005 },
@@ -138,7 +138,7 @@ static const struct ast_dramstruct ast2100_dram_table_data[] = {
 	{ 0x000C, 0x00005a21 },
 	{ 0x0034, 0x00007c03 },
 	{ 0x0120, 0x00005061 },
-	{ 0xffff, 0xffffffff },
+	AST_DRAMSTRUCT_INVALID,
 };
 
 /*
@@ -287,11 +287,11 @@ static void ast_post_chip_2100(struct ast_device *ast)
 			;
 		} while (ast_read32(ast, 0x10000) != 0x01);
 
-		while (dram_reg_info->index != 0xffff) {
-			if (dram_reg_info->index == 0xff00) {/* delay fn */
+		while (!AST_DRAMSTRUCT_IS(dram_reg_info, INVALID)) {
+			if (AST_DRAMSTRUCT_IS(dram_reg_info, UDELAY)) {
 				for (i = 0; i < 15; i++)
 					udelay(dram_reg_info->data);
-			} else if (dram_reg_info->index == 0x4) {
+			} else if (AST_DRAMSTRUCT_IS(dram_reg_info, DRAM_TYPE)) {
 				data = dram_reg_info->data;
 				if (ast->dram_type == AST_DRAM_1Gx16)
 					data = 0x00000d89;

drivers/gpu/drm/ast/ast_post.h

@@ -3,6 +3,7 @@
 #ifndef AST_POST_H
 #define AST_POST_H
 
+#include <linux/limits.h>
 #include <linux/types.h>
 
 struct ast_device;
@@ -13,6 +14,27 @@ struct ast_dramstruct {
 	u32 data;
 };
 
+/* hardware fields */
+#define __AST_DRAMSTRUCT_DRAM_TYPE      0x0004
+
+/* control commands */
+#define __AST_DRAMSTRUCT_UDELAY         0xff00
+#define __AST_DRAMSTRUCT_INVALID        0xffff
+
+#define __AST_DRAMSTRUCT_INDEX(_name) \
+	(__AST_DRAMSTRUCT_ ## _name)
+
+#define AST_DRAMSTRUCT_INIT(_name, _value) \
+	{ __AST_DRAMSTRUCT_INDEX(_name), (_value) }
+
+#define AST_DRAMSTRUCT_UDELAY(_usecs) \
+	AST_DRAMSTRUCT_INIT(UDELAY, _usecs)
+#define AST_DRAMSTRUCT_INVALID \
+	AST_DRAMSTRUCT_INIT(INVALID, U32_MAX)
+
+#define AST_DRAMSTRUCT_IS(_entry, _name) \
+	((_entry)->index == __AST_DRAMSTRUCT_INDEX(_name))
+
 u32 __ast_mindwm(void __iomem *regs, u32 r);
 void __ast_moutdwm(void __iomem *regs, u32 r, u32 v);