drm/ast: Detect ast device type and config mode without ast device

Return the ast chip and config in the detection function's parameters
instead of storing them directly in the ast device instance.

v2:
	* add break statements to switch default branches (Jocelyn)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231116100240.22975-10-tzimmermann@suse.de

drivers/gpu/drm/ast/ast_main.c

@@ -76,25 +76,27 @@ static void ast_open_key(void __iomem *ioregs)
 	__ast_write8_i(ioregs, AST_IO_VGACRI, 0x80, AST_IO_VGACR80_PASSWORD);
 }
 
-static int ast_device_config_init(struct ast_device *ast)
+static int ast_detect_chip(struct pci_dev *pdev,
+			   void __iomem *regs, void __iomem *ioregs,
+			   enum ast_chip *chip_out,
+			   enum ast_config_mode *config_mode_out)
 {
-	struct drm_device *dev = &ast->base;
-	struct pci_dev *pdev = to_pci_dev(dev->dev);
-	struct device_node *np = dev->dev->of_node;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	enum ast_config_mode config_mode = ast_use_defaults;
 	uint32_t scu_rev = 0xffffffff;
+	enum ast_chip chip;
 	u32 data;
-	u8 jregd0, jregd1;
+	u8 vgacrd0, vgacrd1;
 
 	/*
 	 * Find configuration mode and read SCU revision
 	 */
 
-	ast->config_mode = ast_use_defaults;
-
 	/* Check if we have device-tree properties */
 	if (np && !of_property_read_u32(np, "aspeed,scu-revision-id", &data)) {
 		/* We do, disable P2A access */
-		ast->config_mode = ast_use_dt;
+		config_mode = ast_use_dt;
 		scu_rev = data;
 	} else if (pdev->device == PCI_CHIP_AST2000) { // Not all families have a P2A bridge
 		/*
@@ -102,9 +104,9 @@ static int ast_device_config_init(struct ast_device *ast)
 		 * is disabled. We force using P2A if VGA only mode bit
 		 * is set D[7]
 		 */
-		jregd0 = ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xd0, 0xff);
-		jregd1 = ast_get_index_reg_mask(ast, AST_IO_VGACRI, 0xd1, 0xff);
-		if (!(jregd0 & 0x80) || !(jregd1 & 0x10)) {
+		vgacrd0 = __ast_read8_i(ioregs, AST_IO_VGACRI, 0xd0);
+		vgacrd1 = __ast_read8_i(ioregs, AST_IO_VGACRI, 0xd1);
+		if (!(vgacrd0 & 0x80) || !(vgacrd1 & 0x10)) {
 
 			/*
 			 * We have a P2A bridge and it is enabled.
@@ -112,32 +114,32 @@ static int ast_device_config_init(struct ast_device *ast)
 
 			/* Patch AST2500/AST2510 */
 			if ((pdev->revision & 0xf0) == 0x40) {
-				if (!(jregd0 & AST_VRAM_INIT_STATUS_MASK))
-					ast_patch_ahb_2500(ast->regs);
+				if (!(vgacrd0 & AST_VRAM_INIT_STATUS_MASK))
+					ast_patch_ahb_2500(regs);
 			}
 
 			/* Double check that it's actually working */
-			data = ast_read32(ast, 0xf004);
+			data = __ast_read32(regs, 0xf004);
 			if ((data != 0xffffffff) && (data != 0x00)) {
-				ast->config_mode = ast_use_p2a;
+				config_mode = ast_use_p2a;
 
 				/* Read SCU7c (silicon revision register) */
-				ast_write32(ast, 0xf004, 0x1e6e0000);
-				ast_write32(ast, 0xf000, 0x1);
-				scu_rev = ast_read32(ast, 0x1207c);
+				__ast_write32(regs, 0xf004, 0x1e6e0000);
+				__ast_write32(regs, 0xf000, 0x1);
+				scu_rev = __ast_read32(regs, 0x1207c);
 			}
 		}
 	}
 
-	switch (ast->config_mode) {
+	switch (config_mode) {
 	case ast_use_defaults:
-		drm_info(dev, "Using default configuration\n");
+		dev_info(dev, "Using default configuration\n");
 		break;
 	case ast_use_dt:
-		drm_info(dev, "Using device-tree for configuration\n");
+		dev_info(dev, "Using device-tree for configuration\n");
 		break;
 	case ast_use_p2a:
-		drm_info(dev, "Using P2A bridge for configuration\n");
+		dev_info(dev, "Using P2A bridge for configuration\n");
 		break;
 	}
 
@@ -146,63 +148,68 @@ static int ast_device_config_init(struct ast_device *ast)
 	 */
 
 	if (pdev->revision >= 0x50) {
-		ast->chip = AST2600;
-		drm_info(dev, "AST 2600 detected\n");
+		chip = AST2600;
+		dev_info(dev, "AST 2600 detected\n");
 	} else if (pdev->revision >= 0x40) {
 		switch (scu_rev & 0x300) {
 		case 0x0100:
-			ast->chip = AST2510;
-			drm_info(dev, "AST 2510 detected\n");
+			chip = AST2510;
+			dev_info(dev, "AST 2510 detected\n");
 			break;
 		default:
-			ast->chip = AST2500;
-			drm_info(dev, "AST 2500 detected\n");
+			chip = AST2500;
+			dev_info(dev, "AST 2500 detected\n");
+			break;
 		}
 	} else if (pdev->revision >= 0x30) {
 		switch (scu_rev & 0x300) {
 		case 0x0100:
-			ast->chip = AST1400;
-			drm_info(dev, "AST 1400 detected\n");
+			chip = AST1400;
+			dev_info(dev, "AST 1400 detected\n");
 			break;
 		default:
-			ast->chip = AST2400;
-			drm_info(dev, "AST 2400 detected\n");
+			chip = AST2400;
+			dev_info(dev, "AST 2400 detected\n");
+			break;
 		}
 	} else if (pdev->revision >= 0x20) {
 		switch (scu_rev & 0x300) {
 		case 0x0000:
-			ast->chip = AST1300;
-			drm_info(dev, "AST 1300 detected\n");
+			chip = AST1300;
+			dev_info(dev, "AST 1300 detected\n");
 			break;
 		default:
-			ast->chip = AST2300;
-			drm_info(dev, "AST 2300 detected\n");
+			chip = AST2300;
+			dev_info(dev, "AST 2300 detected\n");
 			break;
 		}
 	} else if (pdev->revision >= 0x10) {
 		switch (scu_rev & 0x0300) {
 		case 0x0200:
-			ast->chip = AST1100;
-			drm_info(dev, "AST 1100 detected\n");
+			chip = AST1100;
+			dev_info(dev, "AST 1100 detected\n");
 			break;
 		case 0x0100:
-			ast->chip = AST2200;
-			drm_info(dev, "AST 2200 detected\n");
+			chip = AST2200;
+			dev_info(dev, "AST 2200 detected\n");
 			break;
 		case 0x0000:
-			ast->chip = AST2150;
-			drm_info(dev, "AST 2150 detected\n");
+			chip = AST2150;
+			dev_info(dev, "AST 2150 detected\n");
 			break;
 		default:
-			ast->chip = AST2100;
-			drm_info(dev, "AST 2100 detected\n");
+			chip = AST2100;
+			dev_info(dev, "AST 2100 detected\n");
 			break;
 		}
 	} else {
-		ast->chip = AST2000;
-		drm_info(dev, "AST 2000 detected\n");
+		chip = AST2000;
+		dev_info(dev, "AST 2000 detected\n");
 	}
 
+	*chip_out = chip;
+	*config_mode_out = config_mode;
+
 	return 0;
 }
 
@@ -431,6 +438,8 @@ struct ast_device *ast_device_create(const struct drm_driver *drv,
 	int ret = 0;
 	void __iomem *regs;
 	void __iomem *ioregs;
+	enum ast_config_mode config_mode;
+	enum ast_chip chip;
 
 	ast = devm_drm_dev_alloc(&pdev->dev, drv, struct ast_device, base);
 	if (IS_ERR(ast))
@@ -502,10 +511,13 @@ struct ast_device *ast_device_create(const struct drm_driver *drv,
 	if (ret)
 		return ERR_PTR(ret);
 
-	ret = ast_device_config_init(ast);
+	ret = ast_detect_chip(pdev, regs, ioregs, &chip, &config_mode);
 	if (ret)
 		return ERR_PTR(ret);
 
+	ast->chip = chip;
+	ast->config_mode = config_mode;
+
 	ast_detect_widescreen(ast);
 	ast_detect_tx_chip(ast, need_post);