drm/ast: Merge config and chip detection

Detection of the configuration mode and the chipset model are
linked to each other. One uses values from the other; namely the
PCI device revision and the SCU revision. Merge this code into
a single function.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
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/20230621130032.3568-15-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
index 7ade96f..8bfbdfd 100644 (file)
--- a/drivers/gpu/drm/ast/ast_main.c
+++ b/drivers/gpu/drm/ast/ast_main.c
@@ -96,68 +96,75 @@ static void ast_open_key(struct ast_device *ast)
        ast_set_index_reg(ast, AST_IO_CRTC_PORT, 0x80, 0xA8);
 }
 
-static void ast_detect_config_mode(struct drm_device *dev, u32 *scu_rev)
+static int ast_device_config_init(struct ast_device *ast)
 {
-       struct device_node *np = dev->dev->of_node;
-       struct ast_device *ast = to_ast_device(dev);
+       struct drm_device *dev = &ast->base;
        struct pci_dev *pdev = to_pci_dev(dev->dev);
-       uint32_t data, jregd0, jregd1;
+       struct device_node *np = dev->dev->of_node;
+       uint32_t scu_rev = 0xffffffff;
+       u32 data;
+       u8 jregd0, jregd1;
+
+       /*
+        * Find configuration mode and read SCU revision
+        */
 
-       /* Defaults */
        ast->config_mode = ast_use_defaults;
 
        /* Check if we have device-tree properties */
-       if (np && !of_property_read_u32(np, "aspeed,scu-revision-id",
-                                       scu_rev)) {
+       if (np && !of_property_read_u32(np, "aspeed,scu-revision-id", &data)) {
                /* We do, disable P2A access */
                ast->config_mode = ast_use_dt;
-               drm_info(dev, "Using device-tree for configuration\n");
-               return;
-       }
+               scu_rev = data;
+       } else if (pdev->device == PCI_CHIP_AST2000) { // Not all families have a P2A bridge
+               /*
+                * The BMC will set SCU 0x40 D[12] to 1 if the P2 bridge
+                * is disabled. We force using P2A if VGA only mode bit
+                * is set D[7]
+                */
+               jregd0 = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xd0, 0xff);
+               jregd1 = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xd1, 0xff);
+               if (!(jregd0 & 0x80) || !(jregd1 & 0x10)) {
+
+                       /*
+                        * We have a P2A bridge and it is enabled.
+                        */
+
+                       /* Patch AST2500/AST2510 */
+                       if ((pdev->revision & 0xf0) == 0x40) {
+                               if (!(jregd0 & AST_VRAM_INIT_STATUS_MASK))
+                                       ast_patch_ahb_2500(ast);
+                       }
 
-       /* Not all families have a P2A bridge */
-       if (pdev->device != PCI_CHIP_AST2000)
-               return;
+                       /* Double check that it's actually working */
+                       data = ast_read32(ast, 0xf004);
+                       if ((data != 0xffffffff) && (data != 0x00)) {
+                               ast->config_mode = ast_use_p2a;
 
-       /*
-        * The BMC will set SCU 0x40 D[12] to 1 if the P2 bridge
-        * is disabled. We force using P2A if VGA only mode bit
-        * is set D[7]
-        */
-       jregd0 = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xd0, 0xff);
-       jregd1 = ast_get_index_reg_mask(ast, AST_IO_CRTC_PORT, 0xd1, 0xff);
-       if (!(jregd0 & 0x80) || !(jregd1 & 0x10)) {
-               /* Patch GEN6 */
-               if (((pdev->revision & 0xF0) == 0x40)
-                       && ((jregd0 & AST_VRAM_INIT_STATUS_MASK) == 0))
-                       ast_patch_ahb_2500(ast);
-
-               /* Double check it's actually working */
-               data = ast_read32(ast, 0xf004);
-               if ((data != 0xFFFFFFFF) && (data != 0x00)) {
-                       /* P2A works, grab silicon revision */
-                       ast->config_mode = ast_use_p2a;
-
-                       drm_info(dev, "Using P2A bridge for configuration\n");
-
-                       /* Read SCU7c (silicon revision register) */
-                       ast_write32(ast, 0xf004, 0x1e6e0000);
-                       ast_write32(ast, 0xf000, 0x1);
-                       *scu_rev = ast_read32(ast, 0x1207c);
-                       return;
+                               /* Read SCU7c (silicon revision register) */
+                               ast_write32(ast, 0xf004, 0x1e6e0000);
+                               ast_write32(ast, 0xf000, 0x1);
+                               scu_rev = ast_read32(ast, 0x1207c);
+                       }
                }
        }
 
-       /* We have a P2A bridge but it's disabled */
-       drm_info(dev, "P2A bridge disabled, using default configuration\n");
-}
+       switch (ast->config_mode) {
+       case ast_use_defaults:
+               drm_info(dev, "Using default configuration\n");
+               break;
+       case ast_use_dt:
+               drm_info(dev, "Using device-tree for configuration\n");
+               break;
+       case ast_use_p2a:
+               drm_info(dev, "Using P2A bridge for configuration\n");
+               break;
+       }
 
-static int ast_detect_chip(struct drm_device *dev, bool need_post, u32 scu_rev)
-{
-       struct ast_device *ast = to_ast_device(dev);
-       struct pci_dev *pdev = to_pci_dev(dev->dev);
+       /*
+        * Identify chipset
+        */
 
-       /* Identify chipset */
        if (pdev->revision >= 0x50) {
                ast->chip = AST2600;
                drm_info(dev, "AST 2600 detected\n");
@@ -442,7 +449,6 @@ struct ast_device *ast_device_create(const struct drm_driver *drv,
        struct ast_device *ast;
        bool need_post = false;
        int ret = 0;
-       u32 scu_rev = 0xffffffff;
 
        ast = devm_drm_dev_alloc(&pdev->dev, drv, struct ast_device, base);
        if (IS_ERR(ast))
@@ -499,10 +505,10 @@ struct ast_device *ast_device_create(const struct drm_driver *drv,
        if (ret)
                return ERR_PTR(ret);
 
-       /* Find out whether P2A works or whether to use device-tree */
-       ast_detect_config_mode(dev, &scu_rev);
+       ret = ast_device_config_init(ast);
+       if (ret)
+               return ERR_PTR(ret);
 
-       ast_detect_chip(dev, need_post, scu_rev);
        ast_detect_widescreen(ast);
        ast_detect_tx_chip(ast, need_post);