linux/drivers/gpu/drm/sysfb/vesadrm.c

// SPDX-License-Identifier: GPL-2.0-only

#include <linux/aperture.h>
#include <linux/ioport.h>
#include <linux/limits.h>
#include <linux/platform_device.h>
#include <linux/screen_info.h>

#include <drm/clients/drm_client_setup.h>
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_state_helper.h>
#include <drm/drm_connector.h>
#include <drm/drm_damage_helper.h>
#include <drm/drm_device.h>
#include <drm/drm_drv.h>
#include <drm/drm_edid.h>
#include <drm/drm_fbdev_shmem.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_gem_atomic_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_gem_shmem_helper.h>
#include <drm/drm_managed.h>
#include <drm/drm_modeset_helper_vtables.h>
#include <drm/drm_probe_helper.h>

#include <video/edid.h>
#include <video/pixel_format.h>
#include <video/vga.h>

#include "drm_sysfb_helper.h"

#define DRIVER_NAME	"vesadrm"
#define DRIVER_DESC	"DRM driver for VESA platform devices"
#define DRIVER_MAJOR	1
#define DRIVER_MINOR	0

#define VESADRM_GAMMA_LUT_SIZE 256

static const struct drm_format_info *vesadrm_get_format_si(struct drm_device *dev,
							   const struct screen_info *si)
{
	static const struct drm_sysfb_format formats[] = {
		{ PIXEL_FORMAT_XRGB1555, DRM_FORMAT_XRGB1555, },
		{ PIXEL_FORMAT_RGB565, DRM_FORMAT_RGB565, },
		{ PIXEL_FORMAT_RGB888, DRM_FORMAT_RGB888, },
		{ PIXEL_FORMAT_XRGB8888, DRM_FORMAT_XRGB8888, },
		{ PIXEL_FORMAT_XBGR8888, DRM_FORMAT_XBGR8888, },
	};

	return drm_sysfb_get_format_si(dev, formats, ARRAY_SIZE(formats), si);
}

/*
 * VESA device
 */

struct vesadrm_device {
	struct drm_sysfb_device sysfb;

#if defined(CONFIG_X86_32)
	/* VESA Protected Mode interface */
	struct {
		const u8 *PrimaryPalette;
	} pmi;
#endif

	void (*cmap_write)(struct vesadrm_device *vesa, unsigned int index,
			   u16 red, u16 green, u16 blue);

	/* modesetting */
	u32 formats[DRM_SYSFB_PLANE_NFORMATS(1)];
	struct drm_plane primary_plane;
	struct drm_crtc crtc;
	struct drm_encoder encoder;
	struct drm_connector connector;
};

static struct vesadrm_device *to_vesadrm_device(struct drm_device *dev)
{
	return container_of(to_drm_sysfb_device(dev), struct vesadrm_device, sysfb);
}

/*
 * Palette
 */

static void vesadrm_vga_cmap_write(struct vesadrm_device *vesa, unsigned int index,
				   u16 red, u16 green, u16 blue)
{
	u8 i8, r8, g8, b8;

	if (index > 255)
		return;

	i8 = index;
	r8 = red >> 8;
	g8 = green >> 8;
	b8 = blue >> 8;

	outb_p(i8, VGA_PEL_IW);
	outb_p(r8, VGA_PEL_D);
	outb_p(g8, VGA_PEL_D);
	outb_p(b8, VGA_PEL_D);
}

#if defined(CONFIG_X86_32)
static void vesadrm_pmi_cmap_write(struct vesadrm_device *vesa, unsigned int index,
				   u16 red, u16 green, u16 blue)
{
	u32 i32 = index;
	struct {
		u8 b8;
		u8 g8;
		u8 r8;
		u8 x8;
	} PaletteEntry = {
		blue >> 8,
		green >> 8,
		red >> 8,
		0x00,
	};

	if (index > 255)
		return;

	__asm__ __volatile__ (
		"call *(%%esi)"
		: /* no return value */
		: "a" (0x4f09),
		  "b" (0),
		  "c" (1),
		  "d" (i32),
		  "D" (&PaletteEntry),
		  "S" (&vesa->pmi.PrimaryPalette));
}
#endif

static void vesadrm_set_gamma_linear(struct vesadrm_device *vesa,
				     const struct drm_format_info *format)
{
	struct drm_device *dev = &vesa->sysfb.dev;
	size_t i;
	u16 r16, g16, b16;

	switch (format->format) {
	case DRM_FORMAT_XRGB1555:
		for (i = 0; i < 32; ++i) {
			r16 = i * 8 + i / 4;
			r16 |= (r16 << 8) | r16;
			vesa->cmap_write(vesa, i, r16, r16, r16);
		}
		break;
	case DRM_FORMAT_RGB565:
		for (i = 0; i < 32; ++i) {
			r16 = i * 8 + i / 4;
			r16 |= (r16 << 8) | r16;
			g16 = i * 4 + i / 16;
			g16 |= (g16 << 8) | g16;
			b16 = r16;
			vesa->cmap_write(vesa, i, r16, g16, b16);
		}
		for (i = 32; i < 64; ++i) {
			g16 = i * 4 + i / 16;
			g16 |= (g16 << 8) | g16;
			vesa->cmap_write(vesa, i, 0, g16, 0);
		}
		break;
	case DRM_FORMAT_RGB888:
	case DRM_FORMAT_XRGB8888:
	case DRM_FORMAT_BGRX8888:
		for (i = 0; i < 256; ++i) {
			r16 = (i << 8) | i;
			vesa->cmap_write(vesa, i, r16, r16, r16);
		}
		break;
	default:
		drm_warn_once(dev, "Unsupported format %p4cc for gamma correction\n",
			      &format->format);
		break;
	}
}

static void vesadrm_set_gamma_lut(struct vesadrm_device *vesa,
				  const struct drm_format_info *format,
				  struct drm_color_lut *lut)
{
	struct drm_device *dev = &vesa->sysfb.dev;
	size_t i;
	u16 r16, g16, b16;

	switch (format->format) {
	case DRM_FORMAT_XRGB1555:
		for (i = 0; i < 32; ++i) {
			r16 = lut[i * 8 + i / 4].red;
			g16 = lut[i * 8 + i / 4].green;
			b16 = lut[i * 8 + i / 4].blue;
			vesa->cmap_write(vesa, i, r16, g16, b16);
		}
		break;
	case DRM_FORMAT_RGB565:
		for (i = 0; i < 32; ++i) {
			r16 = lut[i * 8 + i / 4].red;
			g16 = lut[i * 4 + i / 16].green;
			b16 = lut[i * 8 + i / 4].blue;
			vesa->cmap_write(vesa, i, r16, g16, b16);
		}
		for (i = 32; i < 64; ++i)
			vesa->cmap_write(vesa, i, 0, lut[i * 4 + i / 16].green, 0);
		break;
	case DRM_FORMAT_RGB888:
	case DRM_FORMAT_XRGB8888:
	case DRM_FORMAT_BGRX8888:
		for (i = 0; i < 256; ++i)
			vesa->cmap_write(vesa, i, lut[i].red, lut[i].green, lut[i].blue);
		break;
	default:
		drm_warn_once(dev, "Unsupported format %p4cc for gamma correction\n",
			      &format->format);
		break;
	}
}

/*
 * Modesetting
 */

static const u64 vesadrm_primary_plane_format_modifiers[] = {
	DRM_SYSFB_PLANE_FORMAT_MODIFIERS,
};

static const struct drm_plane_helper_funcs vesadrm_primary_plane_helper_funcs = {
	DRM_SYSFB_PLANE_HELPER_FUNCS,
};

static const struct drm_plane_funcs vesadrm_primary_plane_funcs = {
	DRM_SYSFB_PLANE_FUNCS,
	.destroy = drm_plane_cleanup,
};

static void vesadrm_crtc_helper_atomic_flush(struct drm_crtc *crtc,
					     struct drm_atomic_state *state)
{
	struct drm_device *dev = crtc->dev;
	struct drm_sysfb_device *sysfb = to_drm_sysfb_device(dev);
	struct vesadrm_device *vesa = to_vesadrm_device(dev);
	struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
	struct drm_sysfb_crtc_state *sysfb_crtc_state = to_drm_sysfb_crtc_state(crtc_state);

	/*
	 * The gamma LUT has to be reloaded after changing the primary
	 * plane's color format.
	 */
	if (crtc_state->enable && crtc_state->color_mgmt_changed) {
		if (sysfb_crtc_state->format == sysfb->fb_format) {
			if (crtc_state->gamma_lut)
				vesadrm_set_gamma_lut(vesa,
						      sysfb_crtc_state->format,
						      crtc_state->gamma_lut->data);
			else
				vesadrm_set_gamma_linear(vesa, sysfb_crtc_state->format);
		} else {
			vesadrm_set_gamma_linear(vesa, sysfb_crtc_state->format);
		}
	}
}

static const struct drm_crtc_helper_funcs vesadrm_crtc_helper_funcs = {
	DRM_SYSFB_CRTC_HELPER_FUNCS,
	.atomic_flush = vesadrm_crtc_helper_atomic_flush,
};

static const struct drm_crtc_funcs vesadrm_crtc_funcs = {
	DRM_SYSFB_CRTC_FUNCS,
	.destroy = drm_crtc_cleanup,
};

static const struct drm_encoder_funcs vesadrm_encoder_funcs = {
	.destroy = drm_encoder_cleanup,
};

static const struct drm_connector_helper_funcs vesadrm_connector_helper_funcs = {
	DRM_SYSFB_CONNECTOR_HELPER_FUNCS,
};

static const struct drm_connector_funcs vesadrm_connector_funcs = {
	DRM_SYSFB_CONNECTOR_FUNCS,
	.destroy = drm_connector_cleanup,
};

static const struct drm_mode_config_funcs vesadrm_mode_config_funcs = {
	DRM_SYSFB_MODE_CONFIG_FUNCS,
};

/*
 * Init / Cleanup
 */

static struct vesadrm_device *vesadrm_device_create(struct drm_driver *drv,
						    struct platform_device *pdev)
{
	const struct screen_info *si;
	const struct drm_format_info *format;
	int width, height, stride;
	u64 vsize;
	struct resource resbuf;
	struct resource *res;
	struct vesadrm_device *vesa;
	struct drm_sysfb_device *sysfb;
	struct drm_device *dev;
	struct resource *mem = NULL;
	void __iomem *screen_base;
	struct drm_plane *primary_plane;
	struct drm_crtc *crtc;
	struct drm_encoder *encoder;
	struct drm_connector *connector;
	unsigned long max_width, max_height;
	size_t nformats;
	int ret;

	si = dev_get_platdata(&pdev->dev);
	if (!si)
		return ERR_PTR(-ENODEV);
	if (screen_info_video_type(si) != VIDEO_TYPE_VLFB)
		return ERR_PTR(-ENODEV);

	/*
	 * VESA DRM driver
	 */

	vesa = devm_drm_dev_alloc(&pdev->dev, drv, struct vesadrm_device, sysfb.dev);
	if (IS_ERR(vesa))
		return ERR_CAST(vesa);
	sysfb = &vesa->sysfb;
	dev = &sysfb->dev;
	platform_set_drvdata(pdev, dev);

	/*
	 * Hardware settings
	 */

	format = vesadrm_get_format_si(dev, si);
	if (!format)
		return ERR_PTR(-EINVAL);
	width = drm_sysfb_get_width_si(dev, si);
	if (width < 0)
		return ERR_PTR(width);
	height = drm_sysfb_get_height_si(dev, si);
	if (height < 0)
		return ERR_PTR(height);
	res = drm_sysfb_get_memory_si(dev, si, &resbuf);
	if (!res)
		return ERR_PTR(-EINVAL);
	stride = drm_sysfb_get_stride_si(dev, si, format, width, height, resource_size(res));
	if (stride < 0)
		return ERR_PTR(stride);
	vsize = drm_sysfb_get_visible_size_si(dev, si, height, stride, resource_size(res));
	if (!vsize)
		return ERR_PTR(-EINVAL);

	drm_dbg(dev, "framebuffer format=%p4cc, size=%dx%d, stride=%d bytes\n",
		&format->format, width, height, stride);

	if (!__screen_info_vbe_mode_nonvga(si)) {
		vesa->cmap_write = vesadrm_vga_cmap_write;
	} else {
#if defined(CONFIG_X86_32)
		phys_addr_t pmi_base = __screen_info_vesapm_info_base(si);

		if (pmi_base) {
			const u16 *pmi_addr = phys_to_virt(pmi_base);

			vesa->pmi.PrimaryPalette = (u8 *)pmi_addr + pmi_addr[2];
			vesa->cmap_write = vesadrm_pmi_cmap_write;
		} else
#endif
		if (format->is_color_indexed)
			drm_warn(dev, "hardware palette is unchangeable, colors may be incorrect\n");
	}

#ifdef CONFIG_X86
	if (drm_edid_header_is_valid(edid_info.dummy) == 8)
		sysfb->edid = edid_info.dummy;
#endif
	sysfb->fb_mode = drm_sysfb_mode(width, height, 0, 0);
	sysfb->fb_format = format;
	sysfb->fb_pitch = stride;
	if (vesa->cmap_write)
		sysfb->fb_gamma_lut_size = VESADRM_GAMMA_LUT_SIZE;

	/*
	 * Memory management
	 */

	ret = devm_aperture_acquire_for_platform_device(pdev, res->start, vsize);
	if (ret) {
		drm_err(dev, "could not acquire memory range %pr: %d\n", res, ret);
		return ERR_PTR(ret);
	}

	drm_dbg(dev, "using I/O memory framebuffer at %pr\n", res);

	mem = devm_request_mem_region(&pdev->dev, res->start, vsize, drv->name);
	if (!mem) {
		/*
		 * We cannot make this fatal. Sometimes this comes from magic
		 * spaces our resource handlers simply don't know about. Use
		 * the I/O-memory resource as-is and try to map that instead.
		 */
		drm_warn(dev, "could not acquire memory region %pr\n", res);
		mem = res;
	}

	screen_base = devm_ioremap_wc(&pdev->dev, mem->start, resource_size(mem));
	if (!screen_base)
		return ERR_PTR(-ENOMEM);
	iosys_map_set_vaddr_iomem(&sysfb->fb_addr, screen_base);

	/*
	 * Modesetting
	 */

	ret = drmm_mode_config_init(dev);
	if (ret)
		return ERR_PTR(ret);

	max_width = max_t(unsigned long, width, DRM_SHADOW_PLANE_MAX_WIDTH);
	max_height = max_t(unsigned long, height, DRM_SHADOW_PLANE_MAX_HEIGHT);

	dev->mode_config.min_width = width;
	dev->mode_config.max_width = max_width;
	dev->mode_config.min_height = height;
	dev->mode_config.max_height = max_height;
	dev->mode_config.preferred_depth = format->depth;
	dev->mode_config.funcs = &vesadrm_mode_config_funcs;

	/* Primary plane */

	nformats = drm_fb_build_fourcc_list(dev, &format->format, 1,
					    vesa->formats, ARRAY_SIZE(vesa->formats));

	primary_plane = &vesa->primary_plane;
	ret = drm_universal_plane_init(dev, primary_plane, 0, &vesadrm_primary_plane_funcs,
				       vesa->formats, nformats,
				       vesadrm_primary_plane_format_modifiers,
				       DRM_PLANE_TYPE_PRIMARY, NULL);
	if (ret)
		return ERR_PTR(ret);
	drm_plane_helper_add(primary_plane, &vesadrm_primary_plane_helper_funcs);
	drm_plane_enable_fb_damage_clips(primary_plane);

	/* CRTC */

	crtc = &vesa->crtc;
	ret = drm_crtc_init_with_planes(dev, crtc, primary_plane, NULL,
					&vesadrm_crtc_funcs, NULL);
	if (ret)
		return ERR_PTR(ret);
	drm_crtc_helper_add(crtc, &vesadrm_crtc_helper_funcs);

	if (sysfb->fb_gamma_lut_size) {
		ret = drm_mode_crtc_set_gamma_size(crtc, sysfb->fb_gamma_lut_size);
		if (!ret)
			drm_crtc_enable_color_mgmt(crtc, 0, false, sysfb->fb_gamma_lut_size);
	}

	/* Encoder */

	encoder = &vesa->encoder;
	ret = drm_encoder_init(dev, encoder, &vesadrm_encoder_funcs,
			       DRM_MODE_ENCODER_NONE, NULL);
	if (ret)
		return ERR_PTR(ret);
	encoder->possible_crtcs = drm_crtc_mask(crtc);

	/* Connector */

	connector = &vesa->connector;
	ret = drm_connector_init(dev, connector, &vesadrm_connector_funcs,
				 DRM_MODE_CONNECTOR_Unknown);
	if (ret)
		return ERR_PTR(ret);
	drm_connector_helper_add(connector, &vesadrm_connector_helper_funcs);
	drm_connector_set_panel_orientation_with_quirk(connector,
						       DRM_MODE_PANEL_ORIENTATION_UNKNOWN,
						       width, height);
	if (sysfb->edid)
		drm_connector_attach_edid_property(connector);

	ret = drm_connector_attach_encoder(connector, encoder);
	if (ret)
		return ERR_PTR(ret);

	drm_mode_config_reset(dev);

	return vesa;
}

/*
 * DRM driver
 */

DEFINE_DRM_GEM_FOPS(vesadrm_fops);

static struct drm_driver vesadrm_driver = {
	DRM_GEM_SHMEM_DRIVER_OPS,
	DRM_FBDEV_SHMEM_DRIVER_OPS,
	.name			= DRIVER_NAME,
	.desc			= DRIVER_DESC,
	.major			= DRIVER_MAJOR,
	.minor			= DRIVER_MINOR,
	.driver_features	= DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET,
	.fops			= &vesadrm_fops,
};

/*
 * Platform driver
 */

static int vesadrm_probe(struct platform_device *pdev)
{
	struct vesadrm_device *vesa;
	struct drm_sysfb_device *sysfb;
	struct drm_device *dev;
	int ret;

	vesa = vesadrm_device_create(&vesadrm_driver, pdev);
	if (IS_ERR(vesa))
		return PTR_ERR(vesa);
	sysfb = &vesa->sysfb;
	dev = &sysfb->dev;

	ret = drm_dev_register(dev, 0);
	if (ret)
		return ret;

	drm_client_setup(dev, sysfb->fb_format);

	return 0;
}

static void vesadrm_remove(struct platform_device *pdev)
{
	struct drm_device *dev = platform_get_drvdata(pdev);

	drm_dev_unplug(dev);
}

static struct platform_driver vesadrm_platform_driver = {
	.driver = {
		.name = "vesa-framebuffer",
	},
	.probe = vesadrm_probe,
	.remove = vesadrm_remove,
};

module_platform_driver(vesadrm_platform_driver);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");