drm/kms: driver for virtual cirrus under qemu

This is the initial driver for emulated cirrus GPU found in qemu.
This driver only supports the emulated GPU and doesn't attempt
to bind to any real cirrus GPUs.

This driver is intended to be used with xf86-video-modesetting in userspace.
It requires at least version 0.3.0

This follow the same design as ast and mgag200, and is based on work
done by Matthew Garrett previously.

This GPU has no hw cursor, and it can't scanout 32-bpp, only packed 24-bpp.
i.e. it sucks.

Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 629 insertions, 0 deletions

diff --git a/drivers/gpu/drm/cirrus/cirrus_mode.c b/drivers/gpu/drm/cirrus/cirrus_mode.c
new file mode 100644
index 00000000000..100f6308c50
--- /dev/null
+++ b/drivers/gpu/drm/cirrus/cirrus_mode.c
@@ -0,0 +1,629 @@
+
+/*
+ * Copyright 2012 Red Hat
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License version 2. See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ * Authors: Matthew Garrett
+ *          Dave Airlie
+ *
+ * Portions of this code derived from cirrusfb.c:
+ * drivers/video/cirrusfb.c - driver for Cirrus Logic chipsets
+ *
+ * Copyright 1999-2001 Jeff Garzik <jgarzik@pobox.com>
+ */
+#include "drmP.h"
+#include "drm.h"
+#include "drm_crtc_helper.h"
+
+#include <video/cirrus.h>
+
+#include "cirrus_drv.h"
+
+#define CIRRUS_LUT_SIZE 256
+
+#define PALETTE_INDEX 0x8
+#define PALETTE_DATA 0x9
+
+/*
+ * This file contains setup code for the CRTC.
+ */
+
+static void cirrus_crtc_load_lut(struct drm_crtc *crtc)
+{
+	struct cirrus_crtc *cirrus_crtc = to_cirrus_crtc(crtc);
+	struct drm_device *dev = crtc->dev;
+	struct cirrus_device *cdev = dev->dev_private;
+	int i;
+
+	if (!crtc->enabled)
+		return;
+
+	for (i = 0; i < CIRRUS_LUT_SIZE; i++) {
+		/* VGA registers */
+		WREG8(PALETTE_INDEX, i);
+		WREG8(PALETTE_DATA, cirrus_crtc->lut_r[i]);
+		WREG8(PALETTE_DATA, cirrus_crtc->lut_g[i]);
+		WREG8(PALETTE_DATA, cirrus_crtc->lut_b[i]);
+	}
+}
+
+/*
+ * The DRM core requires DPMS functions, but they make little sense in our
+ * case and so are just stubs
+ */
+
+static void cirrus_crtc_dpms(struct drm_crtc *crtc, int mode)
+{
+	struct drm_device *dev = crtc->dev;
+	struct cirrus_device *cdev = dev->dev_private;
+	u8 sr01, gr0e;
+
+	switch (mode) {
+	case DRM_MODE_DPMS_ON:
+		sr01 = 0x00;
+		gr0e = 0x00;
+		break;
+	case DRM_MODE_DPMS_STANDBY:
+		sr01 = 0x20;
+		gr0e = 0x02;
+		break;
+	case DRM_MODE_DPMS_SUSPEND:
+		sr01 = 0x20;
+		gr0e = 0x04;
+		break;
+	case DRM_MODE_DPMS_OFF:
+		sr01 = 0x20;
+		gr0e = 0x06;
+		break;
+	default:
+		return;
+	}
+
+	WREG8(SEQ_INDEX, 0x1);
+	sr01 |= RREG8(SEQ_DATA) & ~0x20;
+	WREG_SEQ(0x1, sr01);
+
+	WREG8(GFX_INDEX, 0xe);
+	gr0e |= RREG8(GFX_DATA) & ~0x06;
+	WREG_GFX(0xe, gr0e);
+}
+
+/*
+ * The core passes the desired mode to the CRTC code to see whether any
+ * CRTC-specific modifications need to be made to it. We're in a position
+ * to just pass that straight through, so this does nothing
+ */
+static bool cirrus_crtc_mode_fixup(struct drm_crtc *crtc,
+				   struct drm_display_mode *mode,
+				   struct drm_display_mode *adjusted_mode)
+{
+	return true;
+}
+
+void cirrus_set_start_address(struct drm_crtc *crtc, unsigned offset)
+{
+	struct cirrus_device *cdev = crtc->dev->dev_private;
+	u32 addr;
+	u8 tmp;
+
+	addr = offset >> 2;
+	WREG_CRT(0x0c, (u8)((addr >> 8) & 0xff));
+	WREG_CRT(0x0d, (u8)(addr & 0xff));
+
+	WREG8(CRT_INDEX, 0x1b);
+	tmp = RREG8(CRT_DATA);
+	tmp &= 0xf2;
+	tmp |= (addr >> 16) & 0x01;
+	tmp |= (addr >> 15) & 0x0c;
+	WREG_CRT(0x1b, tmp);
+	WREG8(CRT_INDEX, 0x1d);
+	tmp = RREG8(CRT_DATA);
+	tmp &= 0x7f;
+	tmp |= (addr >> 12) & 0x80;
+	WREG_CRT(0x1d, tmp);
+}
+
+/* cirrus is different - we will force move buffers out of VRAM */
+static int cirrus_crtc_do_set_base(struct drm_crtc *crtc,
+				struct drm_framebuffer *fb,
+				int x, int y, int atomic)
+{
+	struct cirrus_device *cdev = crtc->dev->dev_private;
+	struct drm_gem_object *obj;
+	struct cirrus_framebuffer *cirrus_fb;
+	struct cirrus_bo *bo;
+	int ret;
+	u64 gpu_addr;
+
+	/* push the previous fb to system ram */
+	if (!atomic && fb) {
+		cirrus_fb = to_cirrus_framebuffer(fb);
+		obj = cirrus_fb->obj;
+		bo = gem_to_cirrus_bo(obj);
+		ret = cirrus_bo_reserve(bo, false);
+		if (ret)
+			return ret;
+		cirrus_bo_push_sysram(bo);
+		cirrus_bo_unreserve(bo);
+	}
+
+	cirrus_fb = to_cirrus_framebuffer(crtc->fb);
+	obj = cirrus_fb->obj;
+	bo = gem_to_cirrus_bo(obj);
+
+	ret = cirrus_bo_reserve(bo, false);
+	if (ret)
+		return ret;
+
+	ret = cirrus_bo_pin(bo, TTM_PL_FLAG_VRAM, &gpu_addr);
+	if (ret) {
+		cirrus_bo_unreserve(bo);
+		return ret;
+	}
+
+	if (&cdev->mode_info.gfbdev->gfb == cirrus_fb) {
+		/* if pushing console in kmap it */
+		ret = ttm_bo_kmap(&bo->bo, 0, bo->bo.num_pages, &bo->kmap);
+		if (ret)
+			DRM_ERROR("failed to kmap fbcon\n");
+	}
+	cirrus_bo_unreserve(bo);
+
+	cirrus_set_start_address(crtc, (u32)gpu_addr);
+	return 0;
+}
+
+static int cirrus_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y,
+			     struct drm_framebuffer *old_fb)
+{
+	return cirrus_crtc_do_set_base(crtc, old_fb, x, y, 0);
+}
+
+/*
+ * The meat of this driver. The core passes us a mode and we have to program
+ * it. The modesetting here is the bare minimum required to satisfy the qemu
+ * emulation of this hardware, and running this against a real device is
+ * likely to result in an inadequately programmed mode. We've already had
+ * the opportunity to modify the mode, so whatever we receive here should
+ * be something that can be correctly programmed and displayed
+ */
+static int cirrus_crtc_mode_set(struct drm_crtc *crtc,
+				struct drm_display_mode *mode,
+				struct drm_display_mode *adjusted_mode,
+				int x, int y, struct drm_framebuffer *old_fb)
+{
+	struct drm_device *dev = crtc->dev;
+	struct cirrus_device *cdev = dev->dev_private;
+	int hsyncstart, hsyncend, htotal, hdispend;
+	int vtotal, vdispend;
+	int tmp;
+	int sr07 = 0, hdr = 0;
+
+	htotal = mode->htotal / 8;
+	hsyncend = mode->hsync_end / 8;
+	hsyncstart = mode->hsync_start / 8;
+	hdispend = mode->hdisplay / 8;
+
+	vtotal = mode->vtotal;
+	vdispend = mode->vdisplay;
+
+	vdispend -= 1;
+	vtotal -= 2;
+
+	htotal -= 5;
+	hdispend -= 1;
+	hsyncstart += 1;
+	hsyncend += 1;
+
+	WREG_CRT(VGA_CRTC_V_SYNC_END, 0x20);
+	WREG_CRT(VGA_CRTC_H_TOTAL, htotal);
+	WREG_CRT(VGA_CRTC_H_DISP, hdispend);
+	WREG_CRT(VGA_CRTC_H_SYNC_START, hsyncstart);
+	WREG_CRT(VGA_CRTC_H_SYNC_END, hsyncend);
+	WREG_CRT(VGA_CRTC_V_TOTAL, vtotal & 0xff);
+	WREG_CRT(VGA_CRTC_V_DISP_END, vdispend & 0xff);
+
+	tmp = 0x40;
+	if ((vdispend + 1) & 512)
+		tmp |= 0x20;
+	WREG_CRT(VGA_CRTC_MAX_SCAN, tmp);
+
+	/*
+	 * Overflow bits for values that don't fit in the standard registers
+	 */
+	tmp = 16;
+	if (vtotal & 256)
+		tmp |= 1;
+	if (vdispend & 256)
+		tmp |= 2;
+	if ((vdispend + 1) & 256)
+		tmp |= 8;
+	if (vtotal & 512)
+		tmp |= 32;
+	if (vdispend & 512)
+		tmp |= 64;
+	WREG_CRT(VGA_CRTC_OVERFLOW, tmp);
+
+	tmp = 0;
+
+	/* More overflow bits */
+
+	if ((htotal + 5) & 64)
+		tmp |= 16;
+	if ((htotal + 5) & 128)
+		tmp |= 32;
+	if (vtotal & 256)
+		tmp |= 64;
+	if (vtotal & 512)
+		tmp |= 128;
+
+	WREG_CRT(CL_CRT1A, tmp);
+
+	/* Disable Hercules/CGA compatibility */
+	WREG_CRT(VGA_CRTC_MODE, 0x03);
+
+	WREG8(SEQ_INDEX, 0x7);
+	sr07 = RREG8(SEQ_DATA);
+	sr07 &= 0xe0;
+	hdr = 0;
+	switch (crtc->fb->bits_per_pixel) {
+	case 8:
+		sr07 |= 0x11;
+		break;
+	case 16:
+		sr07 |= 0xc1;
+		hdr = 0xc0;
+		break;
+	case 24:
+		sr07 |= 0x15;
+		hdr = 0xc5;
+		break;
+	case 32:
+		sr07 |= 0x19;
+		hdr = 0xc5;
+		break;
+	default:
+		return -1;
+	}
+
+	WREG_SEQ(0x7, sr07);
+
+	/* Program the pitch */
+	tmp = crtc->fb->pitches[0] / 8;
+	WREG_CRT(VGA_CRTC_OFFSET, tmp);
+
+	/* Enable extended blanking and pitch bits, and enable full memory */
+	tmp = 0x22;
+	tmp |= (crtc->fb->pitches[0] >> 7) & 0x10;
+	tmp |= (crtc->fb->pitches[0] >> 6) & 0x40;
+	WREG_CRT(0x1b, tmp);
+
+	/* Enable high-colour modes */
+	WREG_GFX(VGA_GFX_MODE, 0x40);
+
+	/* And set graphics mode */
+	WREG_GFX(VGA_GFX_MISC, 0x01);
+
+	WREG_HDR(hdr);
+	cirrus_crtc_do_set_base(crtc, old_fb, x, y, 0);
+	return 0;
+}
+
+/*
+ * This is called before a mode is programmed. A typical use might be to
+ * enable DPMS during the programming to avoid seeing intermediate stages,
+ * but that's not relevant to us
+ */
+static void cirrus_crtc_prepare(struct drm_crtc *crtc)
+{
+}
+
+/*
+ * This is called after a mode is programmed. It should reverse anything done
+ * by the prepare function
+ */
+static void cirrus_crtc_commit(struct drm_crtc *crtc)
+{
+}
+
+/*
+ * The core can pass us a set of gamma values to program. We actually only
+ * use this for 8-bit mode so can't perform smooth fades on deeper modes,
+ * but it's a requirement that we provide the function
+ */
+static void cirrus_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
+				  u16 *blue, uint32_t start, uint32_t size)
+{
+	struct cirrus_crtc *cirrus_crtc = to_cirrus_crtc(crtc);
+	int i;
+
+	if (size != CIRRUS_LUT_SIZE)
+		return;
+
+	for (i = 0; i < CIRRUS_LUT_SIZE; i++) {
+		cirrus_crtc->lut_r[i] = red[i];
+		cirrus_crtc->lut_g[i] = green[i];
+		cirrus_crtc->lut_b[i] = blue[i];
+	}
+	cirrus_crtc_load_lut(crtc);
+}
+
+/* Simple cleanup function */
+static void cirrus_crtc_destroy(struct drm_crtc *crtc)
+{
+	struct cirrus_crtc *cirrus_crtc = to_cirrus_crtc(crtc);
+
+	drm_crtc_cleanup(crtc);
+	kfree(cirrus_crtc);
+}
+
+/* These provide the minimum set of functions required to handle a CRTC */
+static const struct drm_crtc_funcs cirrus_crtc_funcs = {
+	.gamma_set = cirrus_crtc_gamma_set,
+	.set_config = drm_crtc_helper_set_config,
+	.destroy = cirrus_crtc_destroy,
+};
+
+static const struct drm_crtc_helper_funcs cirrus_helper_funcs = {
+	.dpms = cirrus_crtc_dpms,
+	.mode_fixup = cirrus_crtc_mode_fixup,
+	.mode_set = cirrus_crtc_mode_set,
+	.mode_set_base = cirrus_crtc_mode_set_base,
+	.prepare = cirrus_crtc_prepare,
+	.commit = cirrus_crtc_commit,
+	.load_lut = cirrus_crtc_load_lut,
+};
+
+/* CRTC setup */
+static void cirrus_crtc_init(struct drm_device *dev)
+{
+	struct cirrus_device *cdev = dev->dev_private;
+	struct cirrus_crtc *cirrus_crtc;
+	int i;
+
+	cirrus_crtc = kzalloc(sizeof(struct cirrus_crtc) +
+			      (CIRRUSFB_CONN_LIMIT * sizeof(struct drm_connector *)),
+			      GFP_KERNEL);
+
+	if (cirrus_crtc == NULL)
+		return;
+
+	drm_crtc_init(dev, &cirrus_crtc->base, &cirrus_crtc_funcs);
+
+	drm_mode_crtc_set_gamma_size(&cirrus_crtc->base, CIRRUS_LUT_SIZE);
+	cdev->mode_info.crtc = cirrus_crtc;
+
+	for (i = 0; i < CIRRUS_LUT_SIZE; i++) {
+		cirrus_crtc->lut_r[i] = i;
+		cirrus_crtc->lut_g[i] = i;
+		cirrus_crtc->lut_b[i] = i;
+	}
+
+	drm_crtc_helper_add(&cirrus_crtc->base, &cirrus_helper_funcs);
+}
+
+/** Sets the color ramps on behalf of fbcon */
+void cirrus_crtc_fb_gamma_set(struct drm_crtc *crtc, u16 red, u16 green,
+			      u16 blue, int regno)
+{
+	struct cirrus_crtc *cirrus_crtc = to_cirrus_crtc(crtc);
+
+	cirrus_crtc->lut_r[regno] = red;
+	cirrus_crtc->lut_g[regno] = green;
+	cirrus_crtc->lut_b[regno] = blue;
+}
+
+/** Gets the color ramps on behalf of fbcon */
+void cirrus_crtc_fb_gamma_get(struct drm_crtc *crtc, u16 *red, u16 *green,
+			      u16 *blue, int regno)
+{
+	struct cirrus_crtc *cirrus_crtc = to_cirrus_crtc(crtc);
+
+	*red = cirrus_crtc->lut_r[regno];
+	*green = cirrus_crtc->lut_g[regno];
+	*blue = cirrus_crtc->lut_b[regno];
+}
+
+
+static bool cirrus_encoder_mode_fixup(struct drm_encoder *encoder,
+				  struct drm_display_mode *mode,
+				  struct drm_display_mode *adjusted_mode)
+{
+	return true;
+}
+
+static void cirrus_encoder_mode_set(struct drm_encoder *encoder,
+				struct drm_display_mode *mode,
+				struct drm_display_mode *adjusted_mode)
+{
+}
+
+static void cirrus_encoder_dpms(struct drm_encoder *encoder, int state)
+{
+	return;
+}
+
+static void cirrus_encoder_prepare(struct drm_encoder *encoder)
+{
+}
+
+static void cirrus_encoder_commit(struct drm_encoder *encoder)
+{
+}
+
+void cirrus_encoder_destroy(struct drm_encoder *encoder)
+{
+	struct cirrus_encoder *cirrus_encoder = to_cirrus_encoder(encoder);
+	drm_encoder_cleanup(encoder);
+	kfree(cirrus_encoder);
+}
+
+static const struct drm_encoder_helper_funcs cirrus_encoder_helper_funcs = {
+	.dpms = cirrus_encoder_dpms,
+	.mode_fixup = cirrus_encoder_mode_fixup,
+	.mode_set = cirrus_encoder_mode_set,
+	.prepare = cirrus_encoder_prepare,
+	.commit = cirrus_encoder_commit,
+};
+
+static const struct drm_encoder_funcs cirrus_encoder_encoder_funcs = {
+	.destroy = cirrus_encoder_destroy,
+};
+
+static struct drm_encoder *cirrus_encoder_init(struct drm_device *dev)
+{
+	struct drm_encoder *encoder;
+	struct cirrus_encoder *cirrus_encoder;
+
+	cirrus_encoder = kzalloc(sizeof(struct cirrus_encoder), GFP_KERNEL);
+	if (!cirrus_encoder)
+		return NULL;
+
+	encoder = &cirrus_encoder->base;
+	encoder->possible_crtcs = 0x1;
+
+	drm_encoder_init(dev, encoder, &cirrus_encoder_encoder_funcs,
+			 DRM_MODE_ENCODER_DAC);
+	drm_encoder_helper_add(encoder, &cirrus_encoder_helper_funcs);
+
+	return encoder;
+}
+
+
+int cirrus_vga_get_modes(struct drm_connector *connector)
+{
+	/* Just add a static list of modes */
+	drm_add_modes_noedid(connector, 640, 480);
+	drm_add_modes_noedid(connector, 800, 600);
+	drm_add_modes_noedid(connector, 1024, 768);
+	drm_add_modes_noedid(connector, 1280, 1024);
+
+	return 4;
+}
+
+static int cirrus_vga_mode_valid(struct drm_connector *connector,
+				 struct drm_display_mode *mode)
+{
+	/* Any mode we've added is valid */
+	return MODE_OK;
+}
+
+struct drm_encoder *cirrus_connector_best_encoder(struct drm_connector
+						  *connector)
+{
+	int enc_id = connector->encoder_ids[0];
+	struct drm_mode_object *obj;
+	struct drm_encoder *encoder;
+
+	/* pick the encoder ids */
+	if (enc_id) {
+		obj =
+		    drm_mode_object_find(connector->dev, enc_id,
+					 DRM_MODE_OBJECT_ENCODER);
+		if (!obj)
+			return NULL;
+		encoder = obj_to_encoder(obj);
+		return encoder;
+	}
+	return NULL;
+}
+
+static enum drm_connector_status cirrus_vga_detect(struct drm_connector
+						   *connector, bool force)
+{
+	return connector_status_connected;
+}
+
+static void cirrus_connector_destroy(struct drm_connector *connector)
+{
+	drm_connector_cleanup(connector);
+	kfree(connector);
+}
+
+struct drm_connector_helper_funcs cirrus_vga_connector_helper_funcs = {
+	.get_modes = cirrus_vga_get_modes,
+	.mode_valid = cirrus_vga_mode_valid,
+	.best_encoder = cirrus_connector_best_encoder,
+};
+
+struct drm_connector_funcs cirrus_vga_connector_funcs = {
+	.dpms = drm_helper_connector_dpms,
+	.detect = cirrus_vga_detect,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.destroy = cirrus_connector_destroy,
+};
+
+static struct drm_connector *cirrus_vga_init(struct drm_device *dev)
+{
+	struct drm_connector *connector;
+	struct cirrus_connector *cirrus_connector;
+
+	cirrus_connector = kzalloc(sizeof(struct cirrus_connector), GFP_KERNEL);
+	if (!cirrus_connector)
+		return NULL;
+
+	connector = &cirrus_connector->base;
+
+	drm_connector_init(dev, connector,
+			   &cirrus_vga_connector_funcs, DRM_MODE_CONNECTOR_VGA);
+
+	drm_connector_helper_add(connector, &cirrus_vga_connector_helper_funcs);
+
+	return connector;
+}
+
+
+int cirrus_modeset_init(struct cirrus_device *cdev)
+{
+	struct drm_encoder *encoder;
+	struct drm_connector *connector;
+	int ret;
+
+	drm_mode_config_init(cdev->dev);
+	cdev->mode_info.mode_config_initialized = true;
+
+	cdev->dev->mode_config.max_width = CIRRUS_MAX_FB_WIDTH;
+	cdev->dev->mode_config.max_height = CIRRUS_MAX_FB_HEIGHT;
+
+	cdev->dev->mode_config.fb_base = cdev->mc.vram_base;
+	cdev->dev->mode_config.preferred_depth = 24;
+	/* don't prefer a shadow on virt GPU */
+	cdev->dev->mode_config.prefer_shadow = 0;
+
+	cirrus_crtc_init(cdev->dev);
+
+	encoder = cirrus_encoder_init(cdev->dev);
+	if (!encoder) {
+		DRM_ERROR("cirrus_encoder_init failed\n");
+		return -1;
+	}
+
+	connector = cirrus_vga_init(cdev->dev);
+	if (!connector) {
+		DRM_ERROR("cirrus_vga_init failed\n");
+		return -1;
+	}
+
+	drm_mode_connector_attach_encoder(connector, encoder);
+
+	ret = cirrus_fbdev_init(cdev);
+	if (ret) {
+		DRM_ERROR("cirrus_fbdev_init failed\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+void cirrus_modeset_fini(struct cirrus_device *cdev)
+{
+	cirrus_fbdev_fini(cdev);
+
+	if (cdev->mode_info.mode_config_initialized) {
+		drm_mode_config_cleanup(cdev->dev);
+		cdev->mode_info.mode_config_initialized = false;
+	}
+}