drm/ast: Distinguish among chip generations

ASpeed distinguishes among various generations of the AST graphics
chipset with various models. [1] The most-recent model AST 2600 is
of the 7th generation, the AST 2500 is of the 6th generation, and so
on.

The ast driver simply picks one of the models as representative for
the whole generation. In several places, individual models of the
same generation need to be handled differently, which then requires
additional code for detecting the model.

Introduce different generations of the Aspeed chipset. In the source
code, refer to the generation instead of the representation model where
possible. The few places that require per-model handling are now clearly
marked.

In the enum ast_chip, we arrange each model's value such that it
encodes the generation. This allows for an easy test. The actual values
are ordered, but not of interest to the driver.

v2:
	* use __ast_gen_is_eq() (Jingfeng)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://web.archive.org/web/20141007093258/http://www.aspeedtech.com/products.php?fPath=20 # 1
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Tested-by: Jocelyn Falempe <jfalempe@redhat.com> # AST2600
Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn>
Link: https://patchwork.freedesktop.org/patch/msgid/20230621130032.3568-10-tzimmermann@suse.de

1 files changed, 16 insertions, 19 deletions

diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
index b3c670af6ef2..f711d592da52 100644
--- a/drivers/gpu/drm/ast/ast_mode.c
+++ b/drivers/gpu/drm/ast/ast_mode.c
@@ -342,7 +342,7 @@ static void ast_set_crtc_reg(struct ast_device *ast,
 	u8 jreg05 = 0, jreg07 = 0, jreg09 = 0, jregAC = 0, jregAD = 0, jregAE = 0;
 	u16 temp, precache = 0;
 
-	if ((ast->chip == AST2500 || ast->chip == AST2600) &&
+	if ((IS_AST_GEN6(ast) || IS_AST_GEN7(ast)) &&
 	    (vbios_mode->enh_table->flags & AST2500PreCatchCRT))
 		precache = 40;
 
@@ -384,7 +384,7 @@ static void ast_set_crtc_reg(struct ast_device *ast,
 	ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xAD, 0x00, jregAD);
 
 	// Workaround for HSync Time non octave pixels (1920x1080@60Hz HSync 44 pixels);
-	if ((ast->chip == AST2600) && (mode->crtc_vdisplay == 1080))
+	if (IS_AST_GEN7(ast) && (mode->crtc_vdisplay == 1080))
 		ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xFC, 0xFD, 0x02);
 	else
 		ast_set_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xFC, 0xFD, 0x00);
@@ -466,7 +466,7 @@ static void ast_set_dclk_reg(struct ast_device *ast,
 {
 	const struct ast_vbios_dclk_info *clk_info;
 
-	if ((ast->chip == AST2500) || (ast->chip == AST2600))
+	if (IS_AST_GEN6(ast) || IS_AST_GEN7(ast))
 		clk_info = &dclk_table_ast2500[vbios_mode->enh_table->dclk_index];
 	else
 		clk_info = &dclk_table[vbios_mode->enh_table->dclk_index];
@@ -510,17 +510,13 @@ static void ast_set_color_reg(struct ast_device *ast,
 static void ast_set_crtthd_reg(struct ast_device *ast)
 {
 	/* Set Threshold */
-	if (ast->chip == AST2600) {
+	if (IS_AST_GEN7(ast)) {
 		ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xa7, 0xe0);
 		ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xa6, 0xa0);
-	} else if (ast->chip == AST2300 || ast->chip == AST2400 ||
-	    ast->chip == AST2500) {
+	} else if (IS_AST_GEN6(ast) || IS_AST_GEN5(ast) || IS_AST_GEN4(ast)) {
 		ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xa7, 0x78);
 		ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xa6, 0x60);
-	} else if (ast->chip == AST2100 ||
-		   ast->chip == AST1100 ||
-		   ast->chip == AST2200 ||
-		   ast->chip == AST2150) {
+	} else if (IS_AST_GEN3(ast) || IS_AST_GEN2(ast)) {
 		ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xa7, 0x3f);
 		ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0xa6, 0x2f);
 	} else {
@@ -1082,9 +1078,10 @@ ast_crtc_helper_mode_valid(struct drm_crtc *crtc, const struct drm_display_mode
 		if ((mode->hdisplay == 1152) && (mode->vdisplay == 864))
 			return MODE_OK;
 
-		if ((ast->chip == AST2100) || (ast->chip == AST2200) ||
-		    (ast->chip == AST2300) || (ast->chip == AST2400) ||
-		    (ast->chip == AST2500) || (ast->chip == AST2600)) {
+		if ((ast->chip == AST2100) || // GEN2, but not AST1100 (?)
+		    (ast->chip == AST2200) || // GEN3, but not AST2150 (?)
+		    IS_AST_GEN4(ast) || IS_AST_GEN5(ast) ||
+		    IS_AST_GEN6(ast) || IS_AST_GEN7(ast)) {
 			if ((mode->hdisplay == 1920) && (mode->vdisplay == 1080))
 				return MODE_OK;
 
@@ -1800,12 +1797,12 @@ int ast_mode_config_init(struct ast_device *ast)
 	dev->mode_config.min_height = 0;
 	dev->mode_config.preferred_depth = 24;
 
-	if (ast->chip == AST2100 ||
-	    ast->chip == AST2200 ||
-	    ast->chip == AST2300 ||
-	    ast->chip == AST2400 ||
-	    ast->chip == AST2500 ||
-	    ast->chip == AST2600) {
+	if (ast->chip == AST2100 || // GEN2, but not AST1100 (?)
+	    ast->chip == AST2200 || // GEN3, but not AST2150 (?)
+	    IS_AST_GEN7(ast) ||
+	    IS_AST_GEN6(ast) ||
+	    IS_AST_GEN5(ast) ||
+	    IS_AST_GEN4(ast)) {
 		dev->mode_config.max_width = 1920;
 		dev->mode_config.max_height = 2048;
 	} else {