drm: add Atmel HLCDC Display Controller support

The Atmel HLCDC (HLCD Controller) IP available on some Atmel SoCs (i.e.
at91sam9n12, at91sam9x5 family or sama5d3 family) provides a display
controller device.

This display controller supports at least one primary plane and might
provide several overlays and an hardware cursor depending on the IP
version.

At the moment, this driver only implements an RGB connector to interface
with LCD panels, but support for other kind of external devices might be
added later.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Tested-by: Anthony Harivel <anthony.harivel@emtrion.de>
Tested-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>

1 files changed, 406 insertions, 0 deletions

diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
new file mode 100644
index 000000000000..0409b907de5d
--- /dev/null
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
@@ -0,0 +1,406 @@
+/*
+ * Copyright (C) 2014 Traphandler
+ * Copyright (C) 2014 Free Electrons
+ *
+ * Author: Jean-Jacques Hiblot <jjhiblot@traphandler.com>
+ * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/clk.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+
+#include <drm/drm_crtc.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drmP.h>
+
+#include <video/videomode.h>
+
+#include "atmel_hlcdc_dc.h"
+
+/**
+ * Atmel HLCDC CRTC structure
+ *
+ * @base: base DRM CRTC structure
+ * @hlcdc: pointer to the atmel_hlcdc structure provided by the MFD device
+ * @event: pointer to the current page flip event
+ * @id: CRTC id (returned by drm_crtc_index)
+ * @dpms: DPMS mode
+ */
+struct atmel_hlcdc_crtc {
+	struct drm_crtc base;
+	struct atmel_hlcdc_dc *dc;
+	struct drm_pending_vblank_event *event;
+	int id;
+	int dpms;
+};
+
+static inline struct atmel_hlcdc_crtc *
+drm_crtc_to_atmel_hlcdc_crtc(struct drm_crtc *crtc)
+{
+	return container_of(crtc, struct atmel_hlcdc_crtc, base);
+}
+
+static void atmel_hlcdc_crtc_dpms(struct drm_crtc *c, int mode)
+{
+	struct drm_device *dev = c->dev;
+	struct atmel_hlcdc_crtc *crtc = drm_crtc_to_atmel_hlcdc_crtc(c);
+	struct regmap *regmap = crtc->dc->hlcdc->regmap;
+	unsigned int status;
+
+	if (mode != DRM_MODE_DPMS_ON)
+		mode = DRM_MODE_DPMS_OFF;
+
+	if (crtc->dpms == mode)
+		return;
+
+	pm_runtime_get_sync(dev->dev);
+
+	if (mode != DRM_MODE_DPMS_ON) {
+		regmap_write(regmap, ATMEL_HLCDC_DIS, ATMEL_HLCDC_DISP);
+		while (!regmap_read(regmap, ATMEL_HLCDC_SR, &status) &&
+		       (status & ATMEL_HLCDC_DISP))
+			cpu_relax();
+
+		regmap_write(regmap, ATMEL_HLCDC_DIS, ATMEL_HLCDC_SYNC);
+		while (!regmap_read(regmap, ATMEL_HLCDC_SR, &status) &&
+		       (status & ATMEL_HLCDC_SYNC))
+			cpu_relax();
+
+		regmap_write(regmap, ATMEL_HLCDC_DIS, ATMEL_HLCDC_PIXEL_CLK);
+		while (!regmap_read(regmap, ATMEL_HLCDC_SR, &status) &&
+		       (status & ATMEL_HLCDC_PIXEL_CLK))
+			cpu_relax();
+
+		clk_disable_unprepare(crtc->dc->hlcdc->sys_clk);
+
+		pm_runtime_allow(dev->dev);
+	} else {
+		pm_runtime_forbid(dev->dev);
+
+		clk_prepare_enable(crtc->dc->hlcdc->sys_clk);
+
+		regmap_write(regmap, ATMEL_HLCDC_EN, ATMEL_HLCDC_PIXEL_CLK);
+		while (!regmap_read(regmap, ATMEL_HLCDC_SR, &status) &&
+		       !(status & ATMEL_HLCDC_PIXEL_CLK))
+			cpu_relax();
+
+
+		regmap_write(regmap, ATMEL_HLCDC_EN, ATMEL_HLCDC_SYNC);
+		while (!regmap_read(regmap, ATMEL_HLCDC_SR, &status) &&
+		       !(status & ATMEL_HLCDC_SYNC))
+			cpu_relax();
+
+		regmap_write(regmap, ATMEL_HLCDC_EN, ATMEL_HLCDC_DISP);
+		while (!regmap_read(regmap, ATMEL_HLCDC_SR, &status) &&
+		       !(status & ATMEL_HLCDC_DISP))
+			cpu_relax();
+	}
+
+	pm_runtime_put_sync(dev->dev);
+
+	crtc->dpms = mode;
+}
+
+static int atmel_hlcdc_crtc_mode_set(struct drm_crtc *c,
+				     struct drm_display_mode *mode,
+				     struct drm_display_mode *adj,
+				     int x, int y,
+				     struct drm_framebuffer *old_fb)
+{
+	struct atmel_hlcdc_crtc *crtc = drm_crtc_to_atmel_hlcdc_crtc(c);
+	struct regmap *regmap = crtc->dc->hlcdc->regmap;
+	struct drm_plane *plane = c->primary;
+	struct drm_framebuffer *fb;
+	unsigned long mode_rate;
+	struct videomode vm;
+	unsigned long prate;
+	unsigned int cfg;
+	int div;
+
+	if (atmel_hlcdc_dc_mode_valid(crtc->dc, adj) != MODE_OK)
+		return -EINVAL;
+
+	vm.vfront_porch = adj->crtc_vsync_start - adj->crtc_vdisplay;
+	vm.vback_porch = adj->crtc_vtotal - adj->crtc_vsync_end;
+	vm.vsync_len = adj->crtc_vsync_end - adj->crtc_vsync_start;
+	vm.hfront_porch = adj->crtc_hsync_start - adj->crtc_hdisplay;
+	vm.hback_porch = adj->crtc_htotal - adj->crtc_hsync_end;
+	vm.hsync_len = adj->crtc_hsync_end - adj->crtc_hsync_start;
+
+	regmap_write(regmap, ATMEL_HLCDC_CFG(1),
+		     (vm.hsync_len - 1) | ((vm.vsync_len - 1) << 16));
+
+	regmap_write(regmap, ATMEL_HLCDC_CFG(2),
+		     (vm.vfront_porch - 1) | (vm.vback_porch << 16));
+
+	regmap_write(regmap, ATMEL_HLCDC_CFG(3),
+		     (vm.hfront_porch - 1) | ((vm.hback_porch - 1) << 16));
+
+	regmap_write(regmap, ATMEL_HLCDC_CFG(4),
+		     (adj->crtc_hdisplay - 1) |
+		     ((adj->crtc_vdisplay - 1) << 16));
+
+	cfg = ATMEL_HLCDC_CLKPOL;
+
+	prate = clk_get_rate(crtc->dc->hlcdc->sys_clk);
+	mode_rate = mode->crtc_clock * 1000;
+	if ((prate / 2) < mode_rate) {
+		prate *= 2;
+		cfg |= ATMEL_HLCDC_CLKSEL;
+	}
+
+	div = DIV_ROUND_UP(prate, mode_rate);
+	if (div < 2)
+		div = 2;
+
+	cfg |= ATMEL_HLCDC_CLKDIV(div);
+
+	regmap_update_bits(regmap, ATMEL_HLCDC_CFG(0),
+			   ATMEL_HLCDC_CLKSEL | ATMEL_HLCDC_CLKDIV_MASK |
+			   ATMEL_HLCDC_CLKPOL, cfg);
+
+	cfg = 0;
+
+	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
+		cfg |= ATMEL_HLCDC_VSPOL;
+
+	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
+		cfg |= ATMEL_HLCDC_HSPOL;
+
+	regmap_update_bits(regmap, ATMEL_HLCDC_CFG(5),
+			   ATMEL_HLCDC_HSPOL | ATMEL_HLCDC_VSPOL |
+			   ATMEL_HLCDC_VSPDLYS | ATMEL_HLCDC_VSPDLYE |
+			   ATMEL_HLCDC_DISPPOL | ATMEL_HLCDC_DISPDLY |
+			   ATMEL_HLCDC_VSPSU | ATMEL_HLCDC_VSPHO |
+			   ATMEL_HLCDC_GUARDTIME_MASK,
+			   cfg);
+
+	fb = plane->fb;
+	plane->fb = old_fb;
+
+	return atmel_hlcdc_plane_update_with_mode(plane, c, fb, 0, 0,
+						  adj->hdisplay, adj->vdisplay,
+						  x << 16, y << 16,
+						  adj->hdisplay << 16,
+						  adj->vdisplay << 16,
+						  adj);
+}
+
+int atmel_hlcdc_crtc_mode_set_base(struct drm_crtc *c, int x, int y,
+				   struct drm_framebuffer *old_fb)
+{
+	struct drm_plane *plane = c->primary;
+	struct drm_framebuffer *fb = plane->fb;
+	struct drm_display_mode *mode = &c->hwmode;
+
+	plane->fb = old_fb;
+
+	return plane->funcs->update_plane(plane, c, fb,
+					  0, 0,
+					  mode->hdisplay,
+					  mode->vdisplay,
+					  x << 16, y << 16,
+					  mode->hdisplay << 16,
+					  mode->vdisplay << 16);
+}
+
+static void atmel_hlcdc_crtc_prepare(struct drm_crtc *crtc)
+{
+	atmel_hlcdc_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
+}
+
+static void atmel_hlcdc_crtc_commit(struct drm_crtc *crtc)
+{
+	atmel_hlcdc_crtc_dpms(crtc, DRM_MODE_DPMS_ON);
+}
+
+static bool atmel_hlcdc_crtc_mode_fixup(struct drm_crtc *crtc,
+					const struct drm_display_mode *mode,
+					struct drm_display_mode *adjusted_mode)
+{
+	return true;
+}
+
+static void atmel_hlcdc_crtc_disable(struct drm_crtc *crtc)
+{
+	struct drm_plane *plane;
+
+	atmel_hlcdc_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
+	crtc->primary->funcs->disable_plane(crtc->primary);
+
+	drm_for_each_legacy_plane(plane, &crtc->dev->mode_config.plane_list) {
+		if (plane->crtc != crtc)
+			continue;
+
+		plane->funcs->disable_plane(crtc->primary);
+		plane->crtc = NULL;
+	}
+}
+
+static const struct drm_crtc_helper_funcs lcdc_crtc_helper_funcs = {
+	.mode_fixup = atmel_hlcdc_crtc_mode_fixup,
+	.dpms = atmel_hlcdc_crtc_dpms,
+	.mode_set = atmel_hlcdc_crtc_mode_set,
+	.mode_set_base = atmel_hlcdc_crtc_mode_set_base,
+	.prepare = atmel_hlcdc_crtc_prepare,
+	.commit = atmel_hlcdc_crtc_commit,
+	.disable = atmel_hlcdc_crtc_disable,
+};
+
+static void atmel_hlcdc_crtc_destroy(struct drm_crtc *c)
+{
+	struct atmel_hlcdc_crtc *crtc = drm_crtc_to_atmel_hlcdc_crtc(c);
+
+	drm_crtc_cleanup(c);
+	kfree(crtc);
+}
+
+void atmel_hlcdc_crtc_cancel_page_flip(struct drm_crtc *c,
+				       struct drm_file *file)
+{
+	struct atmel_hlcdc_crtc *crtc = drm_crtc_to_atmel_hlcdc_crtc(c);
+	struct drm_pending_vblank_event *event;
+	struct drm_device *dev = c->dev;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->event_lock, flags);
+	event = crtc->event;
+	if (event && event->base.file_priv == file) {
+		event->base.destroy(&event->base);
+		drm_vblank_put(dev, crtc->id);
+		crtc->event = NULL;
+	}
+	spin_unlock_irqrestore(&dev->event_lock, flags);
+}
+
+static void atmel_hlcdc_crtc_finish_page_flip(struct atmel_hlcdc_crtc *crtc)
+{
+	struct drm_device *dev = crtc->base.dev;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->event_lock, flags);
+	if (crtc->event) {
+		drm_send_vblank_event(dev, crtc->id, crtc->event);
+		drm_vblank_put(dev, crtc->id);
+		crtc->event = NULL;
+	}
+	spin_unlock_irqrestore(&dev->event_lock, flags);
+}
+
+void atmel_hlcdc_crtc_irq(struct drm_crtc *c)
+{
+	drm_handle_vblank(c->dev, 0);
+	atmel_hlcdc_crtc_finish_page_flip(drm_crtc_to_atmel_hlcdc_crtc(c));
+}
+
+static int atmel_hlcdc_crtc_page_flip(struct drm_crtc *c,
+				      struct drm_framebuffer *fb,
+				      struct drm_pending_vblank_event *event,
+				      uint32_t page_flip_flags)
+{
+	struct atmel_hlcdc_crtc *crtc = drm_crtc_to_atmel_hlcdc_crtc(c);
+	struct atmel_hlcdc_plane_update_req req;
+	struct drm_plane *plane = c->primary;
+	struct drm_device *dev = c->dev;
+	unsigned long flags;
+	int ret = 0;
+
+	spin_lock_irqsave(&dev->event_lock, flags);
+	if (crtc->event)
+		ret = -EBUSY;
+	spin_unlock_irqrestore(&dev->event_lock, flags);
+
+	if (ret)
+		return ret;
+
+	memset(&req, 0, sizeof(req));
+	req.crtc_x = 0;
+	req.crtc_y = 0;
+	req.crtc_h = c->mode.crtc_vdisplay;
+	req.crtc_w = c->mode.crtc_hdisplay;
+	req.src_x = c->x << 16;
+	req.src_y = c->y << 16;
+	req.src_w = req.crtc_w << 16;
+	req.src_h = req.crtc_h << 16;
+	req.fb = fb;
+
+	ret = atmel_hlcdc_plane_prepare_update_req(plane, &req, &c->hwmode);
+	if (ret)
+		return ret;
+
+	if (event) {
+		drm_vblank_get(c->dev, crtc->id);
+		spin_lock_irqsave(&dev->event_lock, flags);
+		crtc->event = event;
+		spin_unlock_irqrestore(&dev->event_lock, flags);
+	}
+
+	ret = atmel_hlcdc_plane_apply_update_req(plane, &req);
+	if (ret)
+		crtc->event = NULL;
+	else
+		plane->fb = fb;
+
+	return ret;
+}
+
+static const struct drm_crtc_funcs atmel_hlcdc_crtc_funcs = {
+	.page_flip = atmel_hlcdc_crtc_page_flip,
+	.set_config = drm_crtc_helper_set_config,
+	.destroy = atmel_hlcdc_crtc_destroy,
+};
+
+int atmel_hlcdc_crtc_create(struct drm_device *dev)
+{
+	struct atmel_hlcdc_dc *dc = dev->dev_private;
+	struct atmel_hlcdc_planes *planes = dc->planes;
+	struct atmel_hlcdc_crtc *crtc;
+	int ret;
+	int i;
+
+	crtc = kzalloc(sizeof(*crtc), GFP_KERNEL);
+	if (!crtc)
+		return -ENOMEM;
+
+	crtc->dpms = DRM_MODE_DPMS_OFF;
+	crtc->dc = dc;
+
+	ret = drm_crtc_init_with_planes(dev, &crtc->base,
+				&planes->primary->base,
+				planes->cursor ? &planes->cursor->base : NULL,
+				&atmel_hlcdc_crtc_funcs);
+	if (ret < 0)
+		goto fail;
+
+	crtc->id = drm_crtc_index(&crtc->base);
+
+	if (planes->cursor)
+		planes->cursor->base.possible_crtcs = 1 << crtc->id;
+
+	for (i = 0; i < planes->noverlays; i++)
+		planes->overlays[i]->base.possible_crtcs = 1 << crtc->id;
+
+	drm_crtc_helper_add(&crtc->base, &lcdc_crtc_helper_funcs);
+
+	dc->crtc = &crtc->base;
+
+	return 0;
+
+fail:
+	atmel_hlcdc_crtc_destroy(&crtc->base);
+	return ret;
+}
+