drm/mgag200: Convert to simple KMS helper

The mgag200 supports a single pipeline with only a primary plane. It can
be converted to simple KMS helpers. This also adds support for atomic
modesetting. Wayland compositors, which use pageflip ioctls, can now be
used with mgag200.

v2:
* prepare encoder and CRTC in a separate patch
* remove suspend/resume code in a separate patch
* don't call set_format_regs() in pipe_update()

Signed-off-by: Thomas Zimmermann <[e-mail]>
Tested-by: John Donnelly <[e-mail]>
Acked-by: Sam Ravnborg <[e-mail]>
Acked-by: Emil Velikov <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/mgag200/mgag200_drv.c

···
 }
 
 static struct drm_driver driver = {
-	.driver_features = DRIVER_GEM | DRIVER_MODESET,
+	.driver_features = DRIVER_ATOMIC | DRIVER_GEM | DRIVER_MODESET,
 	.fops = &mgag200_driver_fops,
 	.name = DRIVER_NAME,
 	.desc = DRIVER_DESC,

drivers/gpu/drm/mgag200/mgag200_mode.c

···
 #include <linux/delay.h>
 #include <linux/pci.h>
 
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_atomic_state_helper.h>
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_plane_helper.h>
+#include <drm/drm_print.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_simple_kms_helper.h>
 
···
 {
 	struct drm_device *dev = crtc->dev;
 	struct mga_device *mdev = to_mga_device(dev);
-	struct drm_framebuffer *fb = crtc->primary->fb;
+	struct drm_framebuffer *fb;
 	u16 *r_ptr, *g_ptr, *b_ptr;
 	int i;
 
 	if (!crtc->enabled)
 		return;
+
+	if (!mdev->display_pipe.plane.state)
+		return;
+
+	fb = mdev->display_pipe.plane.state->fb;
 
 	r_ptr = crtc->gamma_store;
 	g_ptr = r_ptr + crtc->gamma_size;
···
 	WREG_ECRT(0x00, crtcext0);
 }
 
-static int mga_crtc_do_set_base(struct mga_device *mdev,
-				const struct drm_framebuffer *fb,
-				const struct drm_framebuffer *old_fb)
-{
-	struct drm_gem_vram_object *gbo;
-	int ret;
-	s64 gpu_addr;
-
-	if (old_fb) {
-		gbo = drm_gem_vram_of_gem(old_fb->obj[0]);
-		drm_gem_vram_unpin(gbo);
-	}
-
-	gbo = drm_gem_vram_of_gem(fb->obj[0]);
-
-	ret = drm_gem_vram_pin(gbo, DRM_GEM_VRAM_PL_FLAG_VRAM);
-	if (ret)
-		return ret;
-	gpu_addr = drm_gem_vram_offset(gbo);
-	if (gpu_addr < 0) {
-		ret = (int)gpu_addr;
-		goto err_drm_gem_vram_unpin;
-	}
-
-	mgag200_set_startadd(mdev, (unsigned long)gpu_addr);
-
-	return 0;
-
-err_drm_gem_vram_unpin:
-	drm_gem_vram_unpin(gbo);
-	return ret;
-}
-
-static int mga_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y,
-				  struct drm_framebuffer *old_fb)
-{
-	struct drm_device *dev = crtc->dev;
-	struct mga_device *mdev = dev->dev_private;
-	struct drm_framebuffer *fb = crtc->primary->fb;
-	unsigned int count;
-
-	do { } while (RREG8(0x1fda) & 0x08);
-	do { } while (!(RREG8(0x1fda) & 0x08));
-
-	count = RREG8(MGAREG_VCOUNT) + 2;
-	do { } while (RREG8(MGAREG_VCOUNT) < count);
-
-	return mga_crtc_do_set_base(mdev, fb, old_fb);
-}
-
 static void mgag200_set_pci_regs(struct mga_device *mdev)
 {
 	uint32_t option = 0, option2 = 0;
···
 	WREG_ECRT(0x06, 0x00);
 }
 
-static int mga_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 mga_device *mdev = to_mga_device(dev);
-	const struct drm_framebuffer *fb = crtc->primary->fb;
-
-	mgag200_init_regs(mdev);
-
-	mgag200_set_format_regs(mdev, fb);
-	mga_crtc_do_set_base(mdev, fb, old_fb);
-	mgag200_set_offset(mdev, fb);
-
-	mgag200_set_mode_regs(mdev, mode);
-
-	if (mdev->type == G200_ER)
-		mgag200_g200er_reset_tagfifo(mdev);
-
-	if (IS_G200_SE(mdev))
-		mgag200_g200se_set_hiprilvl(mdev, mode, fb);
-	else if (mdev->type == G200_EV)
-		mgag200_g200ev_set_hiprilvl(mdev);
-
-	return 0;
-}
-
 static void mga_crtc_dpms(struct drm_crtc *crtc, int mode)
 {
 	struct drm_device *dev = crtc->dev;
···
 {
 	struct drm_device *dev = crtc->dev;
 	struct mga_device *mdev = to_mga_device(dev);
-	const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 	u8 tmp;
 
 	if (mdev->type == G200_WB || mdev->type == G200_EW3)
···
 		WREG_SEQ(0x1, tmp);
 		WREG_SEQ(0, 3);
 	}
-	crtc_funcs->dpms(crtc, DRM_MODE_DPMS_ON);
-}
-
-/*
- * 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 int mga_crtc_gamma_set(struct drm_crtc *crtc, u16 *red, u16 *green,
-			      u16 *blue, uint32_t size,
-			      struct drm_modeset_acquire_ctx *ctx)
-{
-	mga_crtc_load_lut(crtc);
-
-	return 0;
-}
-
-static void mga_crtc_disable(struct drm_crtc *crtc)
-{
-	DRM_DEBUG_KMS("\n");
-	mga_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
-	if (crtc->primary->fb) {
-		struct drm_framebuffer *fb = crtc->primary->fb;
-		struct drm_gem_vram_object *gbo =
-			drm_gem_vram_of_gem(fb->obj[0]);
-		drm_gem_vram_unpin(gbo);
-	}
-	crtc->primary->fb = NULL;
-}
-
-/* These provide the minimum set of functions required to handle a CRTC */
-static const struct drm_crtc_funcs mga_crtc_funcs = {
-	.gamma_set = mga_crtc_gamma_set,
-	.set_config = drm_crtc_helper_set_config,
-	.destroy = drm_crtc_cleanup,
-};
-
-static const struct drm_crtc_helper_funcs mga_helper_funcs = {
-	.disable = mga_crtc_disable,
-	.dpms = mga_crtc_dpms,
-	.mode_set = mga_crtc_mode_set,
-	.mode_set_base = mga_crtc_mode_set_base,
-	.prepare = mga_crtc_prepare,
-	.commit = mga_crtc_commit,
-};
-
-/* CRTC setup */
-static void mga_crtc_init(struct mga_device *mdev)
-{
-	struct drm_device *dev = mdev->dev;
-	struct drm_crtc *crtc = &mdev->display_pipe.crtc;
-
-	drm_crtc_init(dev, crtc, &mga_crtc_funcs);
-
-	drm_mode_crtc_set_gamma_size(crtc, MGAG200_LUT_SIZE);
-
-	drm_crtc_helper_add(crtc, &mga_helper_funcs);
+	mga_crtc_dpms(crtc, DRM_MODE_DPMS_ON);
 }
 
 /*
···
 }
 
 static const struct drm_connector_helper_funcs mga_vga_connector_helper_funcs = {
-	.get_modes = mga_vga_get_modes,
+	.get_modes  = mga_vga_get_modes,
 	.mode_valid = mga_vga_mode_valid,
 };
 
 static const struct drm_connector_funcs mga_vga_connector_funcs = {
-	.dpms = drm_helper_connector_dpms,
-	.fill_modes = drm_helper_probe_single_connector_modes,
-	.destroy = mga_connector_destroy,
+	.reset                  = drm_atomic_helper_connector_reset,
+	.fill_modes             = drm_helper_probe_single_connector_modes,
+	.destroy                = mga_connector_destroy,
+	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state   = drm_atomic_helper_connector_destroy_state,
 };
 
 static int mgag200_vga_connector_init(struct mga_device *mdev)
···
 	return ret;
 }
 
+/*
+ * Simple Display Pipe
+ */
+
+static enum drm_mode_status
+mgag200_simple_display_pipe_mode_valid(struct drm_simple_display_pipe *pipe,
+				       const struct drm_display_mode *mode)
+{
+	return MODE_OK;
+}
+
+static void
+mgag200_simple_display_pipe_enable(struct drm_simple_display_pipe *pipe,
+				   struct drm_crtc_state *crtc_state,
+				   struct drm_plane_state *plane_state)
+{
+	struct drm_crtc *crtc = &pipe->crtc;
+	struct drm_device *dev = crtc->dev;
+	struct mga_device *mdev = to_mga_device(dev);
+	struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
+	struct drm_framebuffer *fb = plane_state->fb;
+	struct drm_gem_vram_object *gbo;
+	s64 gpu_addr;
+
+	gbo = drm_gem_vram_of_gem(fb->obj[0]);
+
+	gpu_addr = drm_gem_vram_offset(gbo);
+	if (drm_WARN_ON_ONCE(dev, gpu_addr < 0))
+		return; /* BUG: BO should have been pinned to VRAM. */
+
+	mga_crtc_prepare(crtc);
+
+	mgag200_set_format_regs(mdev, fb);
+	mgag200_set_mode_regs(mdev, adjusted_mode);
+
+	if (mdev->type == G200_ER)
+		mgag200_g200er_reset_tagfifo(mdev);
+
+	if (IS_G200_SE(mdev))
+		mgag200_g200se_set_hiprilvl(mdev, adjusted_mode, fb);
+	else if (mdev->type == G200_EV)
+		mgag200_g200ev_set_hiprilvl(mdev);
+
+	mga_crtc_commit(crtc);
+}
+
+static void
+mgag200_simple_display_pipe_disable(struct drm_simple_display_pipe *pipe)
+{
+	struct drm_crtc *crtc = &pipe->crtc;
+
+	mga_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
+}
+
+static int
+mgag200_simple_display_pipe_check(struct drm_simple_display_pipe *pipe,
+				  struct drm_plane_state *plane_state,
+				  struct drm_crtc_state *crtc_state)
+{
+	struct drm_plane *plane = plane_state->plane;
+	struct drm_framebuffer *new_fb = plane_state->fb;
+	struct drm_framebuffer *fb = NULL;
+
+	if (!new_fb)
+		return 0;
+
+	if (plane->state)
+		fb = plane->state->fb;
+
+	if (!fb || (fb->format != new_fb->format))
+		crtc_state->mode_changed = true; /* update PLL settings */
+
+	return 0;
+}
+
+static void
+mgag200_simple_display_pipe_update(struct drm_simple_display_pipe *pipe,
+				   struct drm_plane_state *old_state)
+{
+	struct drm_plane *plane = &pipe->plane;
+	struct drm_device *dev = plane->dev;
+	struct mga_device *mdev = to_mga_device(dev);
+	struct drm_plane_state *state = plane->state;
+	struct drm_framebuffer *fb = state->fb;
+	struct drm_gem_vram_object *gbo;
+	s64 gpu_addr;
+
+	if (!fb)
+		return;
+
+	gbo = drm_gem_vram_of_gem(fb->obj[0]);
+
+	gpu_addr = drm_gem_vram_offset(gbo);
+	if (drm_WARN_ON_ONCE(dev, gpu_addr < 0))
+		return; /* BUG: BO should have been pinned to VRAM. */
+
+	mgag200_set_startadd(mdev, (unsigned long)gpu_addr);
+	mgag200_set_offset(mdev, fb);
+}
+
+static const struct drm_simple_display_pipe_funcs
+mgag200_simple_display_pipe_funcs = {
+	.mode_valid = mgag200_simple_display_pipe_mode_valid,
+	.enable	    = mgag200_simple_display_pipe_enable,
+	.disable    = mgag200_simple_display_pipe_disable,
+	.check	    = mgag200_simple_display_pipe_check,
+	.update	    = mgag200_simple_display_pipe_update,
+	.prepare_fb = drm_gem_vram_simple_display_pipe_prepare_fb,
+	.cleanup_fb = drm_gem_vram_simple_display_pipe_cleanup_fb,
+};
+
+static const uint32_t mgag200_simple_display_pipe_formats[] = {
+	DRM_FORMAT_XRGB8888,
+	DRM_FORMAT_RGB565,
+	DRM_FORMAT_RGB888,
+};
+
+static const uint64_t mgag200_simple_display_pipe_fmtmods[] = {
+	DRM_FORMAT_MOD_LINEAR,
+	DRM_FORMAT_MOD_INVALID
+};
+
+/*
+ * Mode config
+ */
+
 static const struct drm_mode_config_funcs mgag200_mode_config_funcs = {
-	.fb_create = drm_gem_fb_create
+	.fb_create     = drm_gem_fb_create,
+	.mode_valid    = drm_vram_helper_mode_valid,
+	.atomic_check  = drm_atomic_helper_check,
+	.atomic_commit = drm_atomic_helper_commit,
 };
 
 static unsigned int mgag200_preferred_depth(struct mga_device *mdev)
···
 int mgag200_modeset_init(struct mga_device *mdev)
 {
 	struct drm_device *dev = mdev->dev;
-	struct drm_encoder *encoder = &mdev->display_pipe.encoder;
 	struct drm_connector *connector = &mdev->connector.base;
+	struct drm_simple_display_pipe *pipe = &mdev->display_pipe;
+	size_t format_count = ARRAY_SIZE(mgag200_simple_display_pipe_formats);
 	int ret;
 
 	mdev->bpp_shifts[0] = 0;
 	mdev->bpp_shifts[1] = 1;
 	mdev->bpp_shifts[2] = 0;
 	mdev->bpp_shifts[3] = 2;
+
+	mgag200_init_regs(mdev);
 
 	ret = drmm_mode_config_init(dev);
 	if (ret) {
···
 
 	dev->mode_config.funcs = &mgag200_mode_config_funcs;
 
-	mga_crtc_init(mdev);
-
-	ret = drm_simple_encoder_init(dev, encoder, DRM_MODE_ENCODER_DAC);
-	if (ret) {
-		drm_err(dev,
-			"drm_simple_encoder_init() failed, error %d\n",
-			ret);
-		return ret;
-	}
-	encoder->possible_crtcs = 0x1;
-
 	ret = mgag200_vga_connector_init(mdev);
 	if (ret) {
 		drm_err(dev,
···
 		return ret;
 	}
 
-	drm_connector_attach_encoder(connector, encoder);
+	ret = drm_simple_display_pipe_init(dev, pipe,
+					   &mgag200_simple_display_pipe_funcs,
+					   mgag200_simple_display_pipe_formats,
+					   format_count,
+					   mgag200_simple_display_pipe_fmtmods,
+					   connector);
+	if (ret) {
+		drm_err(dev,
+			"drm_simple_display_pipe_init() failed, error %d\n",
+			ret);
+		return ret;
+	}
+
+	/* FIXME: legacy gamma tables; convert to CRTC state */
+	drm_mode_crtc_set_gamma_size(&pipe->crtc, MGAG200_LUT_SIZE);
+
+	drm_mode_config_reset(dev);
 
 	return 0;
 }