drm/ofdrm: Add per-model device function

Add a per-model device-function structure in preparation of adding
color-management support. Detection of the individual models has been
taken from fbdev's offb.

v3:
	* define constants for PCI ids (Javier)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221011150712.3928-4-tzimmermann@suse.de

drivers/gpu/drm/tiny/ofdrm.c

@@ -28,6 +28,21 @@
 #define DRIVER_MAJOR	1
 #define DRIVER_MINOR	0
 
+#define PCI_VENDOR_ID_ATI_R520	0x7100
+#define PCI_VENDOR_ID_ATI_R600	0x9400
+
+enum ofdrm_model {
+	OFDRM_MODEL_UNKNOWN,
+	OFDRM_MODEL_MACH64, /* ATI Mach64 */
+	OFDRM_MODEL_RAGE128, /* ATI Rage128 */
+	OFDRM_MODEL_RAGE_M3A, /* ATI Rage Mobility M3 Head A */
+	OFDRM_MODEL_RAGE_M3B, /* ATI Rage Mobility M3 Head B */
+	OFDRM_MODEL_RADEON, /* ATI Radeon */
+	OFDRM_MODEL_GXT2000, /* IBM GXT2000 */
+	OFDRM_MODEL_AVIVO, /* ATI R5xx */
+	OFDRM_MODEL_QEMU, /* QEMU VGA */
+};
+
 /*
  * Helpers for display nodes
  */
@@ -148,14 +163,63 @@ static u64 display_get_address_of(struct drm_device *dev, struct device_node *of
 	return address;
 }
 
+static bool is_avivo(__be32 vendor, __be32 device)
+{
+	/* This will match most R5xx */
+	return (vendor == PCI_VENDOR_ID_ATI) &&
+	       ((device >= PCI_VENDOR_ID_ATI_R520 && device < 0x7800) ||
+		(PCI_VENDOR_ID_ATI_R600 >= 0x9400));
+}
+
+static enum ofdrm_model display_get_model_of(struct drm_device *dev, struct device_node *of_node)
+{
+	enum ofdrm_model model = OFDRM_MODEL_UNKNOWN;
+
+	if (of_node_name_prefix(of_node, "ATY,Rage128")) {
+		model = OFDRM_MODEL_RAGE128;
+	} else if (of_node_name_prefix(of_node, "ATY,RageM3pA") ||
+		   of_node_name_prefix(of_node, "ATY,RageM3p12A")) {
+		model = OFDRM_MODEL_RAGE_M3A;
+	} else if (of_node_name_prefix(of_node, "ATY,RageM3pB")) {
+		model = OFDRM_MODEL_RAGE_M3B;
+	} else if (of_node_name_prefix(of_node, "ATY,Rage6")) {
+		model = OFDRM_MODEL_RADEON;
+	} else if (of_node_name_prefix(of_node, "ATY,")) {
+		return OFDRM_MODEL_MACH64;
+	} else if (of_device_is_compatible(of_node, "pci1014,b7") ||
+		   of_device_is_compatible(of_node, "pci1014,21c")) {
+		model = OFDRM_MODEL_GXT2000;
+	} else if (of_node_name_prefix(of_node, "vga,Display-")) {
+		struct device_node *of_parent;
+		const __be32 *vendor_p, *device_p;
+
+		/* Look for AVIVO initialized by SLOF */
+		of_parent = of_get_parent(of_node);
+		vendor_p = of_get_property(of_parent, "vendor-id", NULL);
+		device_p = of_get_property(of_parent, "device-id", NULL);
+		if (vendor_p && device_p && is_avivo(*vendor_p, *device_p))
+			model = OFDRM_MODEL_AVIVO;
+		of_node_put(of_parent);
+	} else if (of_device_is_compatible(of_node, "qemu,std-vga")) {
+		model = OFDRM_MODEL_QEMU;
+	}
+
+	return model;
+}
+
 /*
  * Open Firmware display device
  */
 
+struct ofdrm_device_funcs {
+};
+
 struct ofdrm_device {
 	struct drm_device dev;
 	struct platform_device *pdev;
 
+	const struct ofdrm_device_funcs *funcs;
+
 	/* firmware-buffer settings */
 	struct iosys_map screen_base;
 	struct drm_display_mode mode;
@@ -522,6 +586,33 @@ static const struct drm_mode_config_funcs ofdrm_mode_config_funcs = {
  * Init / Cleanup
  */
 
+static const struct ofdrm_device_funcs ofdrm_unknown_device_funcs = {
+};
+
+static const struct ofdrm_device_funcs ofdrm_mach64_device_funcs = {
+};
+
+static const struct ofdrm_device_funcs ofdrm_rage128_device_funcs = {
+};
+
+static const struct ofdrm_device_funcs ofdrm_rage_m3a_device_funcs = {
+};
+
+static const struct ofdrm_device_funcs ofdrm_rage_m3b_device_funcs = {
+};
+
+static const struct ofdrm_device_funcs ofdrm_radeon_device_funcs = {
+};
+
+static const struct ofdrm_device_funcs ofdrm_gxt2000_device_funcs = {
+};
+
+static const struct ofdrm_device_funcs ofdrm_avivo_device_funcs = {
+};
+
+static const struct ofdrm_device_funcs ofdrm_qemu_device_funcs = {
+};
+
 static struct drm_display_mode ofdrm_mode(unsigned int width, unsigned int height)
 {
 	/*
@@ -543,6 +634,7 @@ static struct ofdrm_device *ofdrm_device_create(struct drm_driver *drv,
 	struct device_node *of_node = pdev->dev.of_node;
 	struct ofdrm_device *odev;
 	struct drm_device *dev;
+	enum ofdrm_model model;
 	int width, height, depth, linebytes;
 	const struct drm_format_info *format;
 	u64 address;
@@ -571,6 +663,39 @@ static struct ofdrm_device *ofdrm_device_create(struct drm_driver *drv,
 	 * OF display-node settings
 	 */
 
+	model = display_get_model_of(dev, of_node);
+	drm_dbg(dev, "detected model %d\n", model);
+
+	switch (model) {
+	case OFDRM_MODEL_UNKNOWN:
+		odev->funcs = &ofdrm_unknown_device_funcs;
+		break;
+	case OFDRM_MODEL_MACH64:
+		odev->funcs = &ofdrm_mach64_device_funcs;
+		break;
+	case OFDRM_MODEL_RAGE128:
+		odev->funcs = &ofdrm_rage128_device_funcs;
+		break;
+	case OFDRM_MODEL_RAGE_M3A:
+		odev->funcs = &ofdrm_rage_m3a_device_funcs;
+		break;
+	case OFDRM_MODEL_RAGE_M3B:
+		odev->funcs = &ofdrm_rage_m3b_device_funcs;
+		break;
+	case OFDRM_MODEL_RADEON:
+		odev->funcs = &ofdrm_radeon_device_funcs;
+		break;
+	case OFDRM_MODEL_GXT2000:
+		odev->funcs = &ofdrm_gxt2000_device_funcs;
+		break;
+	case OFDRM_MODEL_AVIVO:
+		odev->funcs = &ofdrm_avivo_device_funcs;
+		break;
+	case OFDRM_MODEL_QEMU:
+		odev->funcs = &ofdrm_qemu_device_funcs;
+		break;
+	}
+
 	width = display_get_width_of(dev, of_node);
 	if (width < 0)
 		return ERR_PTR(width);