drm/ast: Move detection code into PCI probe helper

Detect device type and config mode in the PCI probe helper, but leave
DRM device initialization where it is. Structures the driver probe and
setup code into a detection and an initialization phase.

A later patch can add branching to the device-initialization code. Each
chip type can have it own initializer function, if necessary.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231116100240.22975-11-tzimmermann@suse.de

1 files changed, 255 insertions, 8 deletions

diff --git a/drivers/gpu/drm/ast/ast_drv.c b/drivers/gpu/drm/ast/ast_drv.c
index cf5b754f044c..90bcb1eb9cd9 100644
--- a/drivers/gpu/drm/ast/ast_drv.c
+++ b/drivers/gpu/drm/ast/ast_drv.c
@@ -89,11 +89,194 @@ static const struct pci_device_id ast_pciidlist[] = {
 
 MODULE_DEVICE_TABLE(pci, ast_pciidlist);
 
+static bool ast_is_vga_enabled(void __iomem *ioregs)
+{
+	u8 vgaer = __ast_read8(ioregs, AST_IO_VGAER);
+
+	return vgaer & AST_IO_VGAER_VGA_ENABLE;
+}
+
+static void ast_enable_vga(void __iomem *ioregs)
+{
+	__ast_write8(ioregs, AST_IO_VGAER, AST_IO_VGAER_VGA_ENABLE);
+	__ast_write8(ioregs, AST_IO_VGAMR_W, AST_IO_VGAMR_IOSEL);
+}
+
+/*
+ * Run this function as part of the HW device cleanup; not
+ * when the DRM device gets released.
+ */
+static void ast_enable_mmio_release(void *data)
+{
+	void __iomem *ioregs = (void __force __iomem *)data;
+
+	/* enable standard VGA decode */
+	__ast_write8_i(ioregs, AST_IO_VGACRI, 0xa1, AST_IO_VGACRA1_MMIO_ENABLED);
+}
+
+static int ast_enable_mmio(struct device *dev, void __iomem *ioregs)
+{
+	void *data = (void __force *)ioregs;
+
+	__ast_write8_i(ioregs, AST_IO_VGACRI, 0xa1,
+		       AST_IO_VGACRA1_MMIO_ENABLED |
+		       AST_IO_VGACRA1_VGAIO_DISABLED);
+
+	return devm_add_action_or_reset(dev, ast_enable_mmio_release, data);
+}
+
+static void ast_open_key(void __iomem *ioregs)
+{
+	__ast_write8_i(ioregs, AST_IO_VGACRI, 0x80, AST_IO_VGACR80_PASSWORD);
+}
+
+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 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 vgacrd0, vgacrd1;
+
+	/*
+	 * Find configuration mode and read SCU revision
+	 */
+
+	/* Check if we have device-tree properties */
+	if (np && !of_property_read_u32(np, "aspeed,scu-revision-id", &data)) {
+		/* We do, disable P2A access */
+		config_mode = ast_use_dt;
+		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]
+		 */
+		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.
+			 */
+
+			/* Patch AST2500/AST2510 */
+			if ((pdev->revision & 0xf0) == 0x40) {
+				if (!(vgacrd0 & AST_VRAM_INIT_STATUS_MASK))
+					ast_patch_ahb_2500(regs);
+			}
+
+			/* Double check that it's actually working */
+			data = __ast_read32(regs, 0xf004);
+			if ((data != 0xffffffff) && (data != 0x00)) {
+				config_mode = ast_use_p2a;
+
+				/* Read SCU7c (silicon revision register) */
+				__ast_write32(regs, 0xf004, 0x1e6e0000);
+				__ast_write32(regs, 0xf000, 0x1);
+				scu_rev = __ast_read32(regs, 0x1207c);
+			}
+		}
+	}
+
+	switch (config_mode) {
+	case ast_use_defaults:
+		dev_info(dev, "Using default configuration\n");
+		break;
+	case ast_use_dt:
+		dev_info(dev, "Using device-tree for configuration\n");
+		break;
+	case ast_use_p2a:
+		dev_info(dev, "Using P2A bridge for configuration\n");
+		break;
+	}
+
+	/*
+	 * Identify chipset
+	 */
+
+	if (pdev->revision >= 0x50) {
+		chip = AST2600;
+		dev_info(dev, "AST 2600 detected\n");
+	} else if (pdev->revision >= 0x40) {
+		switch (scu_rev & 0x300) {
+		case 0x0100:
+			chip = AST2510;
+			dev_info(dev, "AST 2510 detected\n");
+			break;
+		default:
+			chip = AST2500;
+			dev_info(dev, "AST 2500 detected\n");
+			break;
+		}
+	} else if (pdev->revision >= 0x30) {
+		switch (scu_rev & 0x300) {
+		case 0x0100:
+			chip = AST1400;
+			dev_info(dev, "AST 1400 detected\n");
+			break;
+		default:
+			chip = AST2400;
+			dev_info(dev, "AST 2400 detected\n");
+			break;
+		}
+	} else if (pdev->revision >= 0x20) {
+		switch (scu_rev & 0x300) {
+		case 0x0000:
+			chip = AST1300;
+			dev_info(dev, "AST 1300 detected\n");
+			break;
+		default:
+			chip = AST2300;
+			dev_info(dev, "AST 2300 detected\n");
+			break;
+		}
+	} else if (pdev->revision >= 0x10) {
+		switch (scu_rev & 0x0300) {
+		case 0x0200:
+			chip = AST1100;
+			dev_info(dev, "AST 1100 detected\n");
+			break;
+		case 0x0100:
+			chip = AST2200;
+			dev_info(dev, "AST 2200 detected\n");
+			break;
+		case 0x0000:
+			chip = AST2150;
+			dev_info(dev, "AST 2150 detected\n");
+			break;
+		default:
+			chip = AST2100;
+			dev_info(dev, "AST 2100 detected\n");
+			break;
+		}
+	} else {
+		chip = AST2000;
+		dev_info(dev, "AST 2000 detected\n");
+	}
+
+	*chip_out = chip;
+	*config_mode_out = config_mode;
+
+	return 0;
+}
+
 static int ast_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
-	struct ast_device *ast;
-	struct drm_device *dev;
+	struct device *dev = &pdev->dev;
 	int ret;
+	void __iomem *regs;
+	void __iomem *ioregs;
+	enum ast_config_mode config_mode;
+	enum ast_chip chip;
+	struct drm_device *drm;
+	bool need_post = false;
 
 	ret = drm_aperture_remove_conflicting_pci_framebuffers(pdev, &ast_driver);
 	if (ret)
@@ -103,16 +286,80 @@ static int ast_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (ret)
 		return ret;
 
-	ast = ast_device_create(&ast_driver, pdev, ent->driver_data);
-	if (IS_ERR(ast))
-		return PTR_ERR(ast);
-	dev = &ast->base;
+	regs = pcim_iomap(pdev, 1, 0);
+	if (!regs)
+		return -EIO;
+
+	if (pdev->revision >= 0x40) {
+		/*
+		 * On AST2500 and later models, MMIO is enabled by
+		 * default. Adopt it to be compatible with ARM.
+		 */
+		resource_size_t len = pci_resource_len(pdev, 1);
+
+		if (len < AST_IO_MM_OFFSET)
+			return -EIO;
+		if ((len - AST_IO_MM_OFFSET) < AST_IO_MM_LENGTH)
+			return -EIO;
+		ioregs = regs + AST_IO_MM_OFFSET;
+	} else if (pci_resource_flags(pdev, 2) & IORESOURCE_IO) {
+		/*
+		 * Map I/O registers if we have a PCI BAR for I/O.
+		 */
+		resource_size_t len = pci_resource_len(pdev, 2);
+
+		if (len < AST_IO_MM_LENGTH)
+			return -EIO;
+		ioregs = pcim_iomap(pdev, 2, 0);
+		if (!ioregs)
+			return -EIO;
+	} else {
+		/*
+		 * Anything else is best effort.
+		 */
+		resource_size_t len = pci_resource_len(pdev, 1);
+
+		if (len < AST_IO_MM_OFFSET)
+			return -EIO;
+		if ((len - AST_IO_MM_OFFSET) < AST_IO_MM_LENGTH)
+			return -EIO;
+		ioregs = regs + AST_IO_MM_OFFSET;
+
+		dev_info(dev, "Platform has no I/O space, using MMIO\n");
+	}
+
+	if (!ast_is_vga_enabled(ioregs)) {
+		dev_info(dev, "VGA not enabled on entry, requesting chip POST\n");
+		need_post = true;
+	}
+
+	/*
+	 * If VGA isn't enabled, we need to enable now or subsequent
+	 * access to the scratch registers will fail.
+	 */
+	if (need_post)
+		ast_enable_vga(ioregs);
+	/* Enable extended register access */
+	ast_open_key(ioregs);
+
+	ret = ast_enable_mmio(dev, ioregs);
+	if (ret)
+		return ret;
+
+	ret = ast_detect_chip(pdev, regs, ioregs, &chip, &config_mode);
+	if (ret)
+		return ret;
+
+	drm = ast_device_create(pdev, &ast_driver, chip, config_mode, regs, ioregs, need_post);
+	if (IS_ERR(drm))
+		return PTR_ERR(drm);
+	pci_set_drvdata(pdev, drm);
 
-	ret = drm_dev_register(dev, ent->driver_data);
+	ret = drm_dev_register(drm, ent->driver_data);
 	if (ret)
 		return ret;
 
-	drm_fbdev_generic_setup(dev, 32);
+	drm_fbdev_generic_setup(drm, 32);
 
 	return 0;
 }