drm/ast: Move Gen1 device initialization into separate helper

Split off device initialization for Gen1 hardware into the helper
ast_2000_device_create(). The new function is a duplicate of their
counterpart in ast_main.c, but stripped from most non-Gen1 support.

Simplifies maintenance as the driver's number of supported hardware
generations grows.

v2:
- remove unnecessary widescreen-detection logic

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20250922083708.45564-6-tzimmermann@suse.de

3 files changed, 52 insertions, 0 deletions

diff --git a/drivers/gpu/drm/ast/ast_2000.c b/drivers/gpu/drm/ast/ast_2000.c
index 63fad9fbf519..03b0dcea43d1 100644
--- a/drivers/gpu/drm/ast/ast_2000.c
+++ b/drivers/gpu/drm/ast/ast_2000.c
@@ -27,6 +27,9 @@
  */
 
 #include <linux/delay.h>
+#include <linux/pci.h>
+
+#include <drm/drm_drv.h>
 
 #include "ast_drv.h"
 #include "ast_post.h"
@@ -207,3 +210,41 @@ void ast_2000_detect_tx_chip(struct ast_device *ast, bool need_post)
 
 	__ast_device_set_tx_chip(ast, tx_chip);
 }
+
+struct drm_device *ast_2000_device_create(struct pci_dev *pdev,
+					  const struct drm_driver *drv,
+					  enum ast_chip chip,
+					  enum ast_config_mode config_mode,
+					  void __iomem *regs,
+					  void __iomem *ioregs,
+					  bool need_post)
+{
+	struct drm_device *dev;
+	struct ast_device *ast;
+	int ret;
+
+	ast = devm_drm_dev_alloc(&pdev->dev, drv, struct ast_device, base);
+	if (IS_ERR(ast))
+		return ERR_CAST(ast);
+	dev = &ast->base;
+
+	ast_device_init(ast, chip, config_mode, regs, ioregs);
+
+	ast_2000_detect_tx_chip(ast, need_post);
+
+	if (need_post) {
+		ret = ast_post_gpu(ast);
+		if (ret)
+			return ERR_PTR(ret);
+	}
+
+	ret = ast_mm_init(ast);
+	if (ret)
+		return ERR_PTR(ret);
+
+	ret = ast_mode_config_init(ast);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return dev;
+}
diff --git a/drivers/gpu/drm/ast/ast_drv.c b/drivers/gpu/drm/ast/ast_drv.c
index a1b3c25ded20..3fecdc0fc7f7 100644
--- a/drivers/gpu/drm/ast/ast_drv.c
+++ b/drivers/gpu/drm/ast/ast_drv.c
@@ -382,6 +382,10 @@ static int ast_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	chip_gen = ret;
 
 	switch (chip_gen) {
+	case 1:
+		drm = ast_2000_device_create(pdev, &ast_driver, chip, config_mode,
+					     regs, ioregs, need_post);
+		break;
 	default:
 		drm = ast_device_create(pdev, &ast_driver, chip, config_mode, regs, ioregs,
 					need_post);
diff --git a/drivers/gpu/drm/ast/ast_drv.h b/drivers/gpu/drm/ast/ast_drv.h
index 8868cbdd99d0..369abdd81bbf 100644
--- a/drivers/gpu/drm/ast/ast_drv.h
+++ b/drivers/gpu/drm/ast/ast_drv.h
@@ -427,6 +427,13 @@ void __ast_device_set_tx_chip(struct ast_device *ast, enum ast_tx_chip tx_chip);
 int ast_2000_post(struct ast_device *ast);
 extern const struct ast_vbios_dclk_info ast_2000_dclk_table[];
 void ast_2000_detect_tx_chip(struct ast_device *ast, bool need_post);
+struct drm_device *ast_2000_device_create(struct pci_dev *pdev,
+					  const struct drm_driver *drv,
+					  enum ast_chip chip,
+					  enum ast_config_mode config_mode,
+					  void __iomem *regs,
+					  void __iomem *ioregs,
+					  bool need_post);
 
 /* ast_2100.c */
 int ast_2100_post(struct ast_device *ast);