drm: Add support for ARM's HDLCD controller.

The HDLCD controller is a display controller that supports resolutions
up to 4096x4096 pixels. It is present on various development boards
produced by ARM Ltd and emulated by the latest Fast Models from the
company.

Cc: David Airlie <airlied@linux.ie>
Cc: Robin Murphy <robin.murphy@arm.com>

Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
[Kconfig cleanup and !CONFIG_PM fixes]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 327 insertions, 0 deletions

diff --git a/drivers/gpu/drm/arm/hdlcd_crtc.c b/drivers/gpu/drm/arm/hdlcd_crtc.c
new file mode 100644
index 000000000000..fef1b04c2aab
--- /dev/null
+++ b/drivers/gpu/drm/arm/hdlcd_crtc.c
@@ -0,0 +1,327 @@
+/*
+ * Copyright (C) 2013-2015 ARM Limited
+ * Author: Liviu Dudau <Liviu.Dudau@arm.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ *
+ *  Implementation of a CRTC class for the HDLCD driver.
+ */
+
+#include <drm/drmP.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_of.h>
+#include <drm/drm_plane_helper.h>
+#include <linux/clk.h>
+#include <linux/of_graph.h>
+#include <linux/platform_data/simplefb.h>
+#include <video/videomode.h>
+
+#include "hdlcd_drv.h"
+#include "hdlcd_regs.h"
+
+/*
+ * The HDLCD controller is a dumb RGB streamer that gets connected to
+ * a single HDMI transmitter or in the case of the ARM Models it gets
+ * emulated by the software that does the actual rendering.
+ *
+ */
+
+static const struct drm_crtc_funcs hdlcd_crtc_funcs = {
+	.destroy = drm_crtc_cleanup,
+	.set_config = drm_atomic_helper_set_config,
+	.page_flip = drm_atomic_helper_page_flip,
+	.reset = drm_atomic_helper_crtc_reset,
+	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
+};
+
+static struct simplefb_format supported_formats[] = SIMPLEFB_FORMATS;
+
+/*
+ * Setup the HDLCD registers for decoding the pixels out of the framebuffer
+ */
+static int hdlcd_set_pxl_fmt(struct drm_crtc *crtc)
+{
+	unsigned int btpp;
+	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
+	uint32_t pixel_format;
+	struct simplefb_format *format = NULL;
+	int i;
+
+	pixel_format = crtc->primary->state->fb->pixel_format;
+
+	for (i = 0; i < ARRAY_SIZE(supported_formats); i++) {
+		if (supported_formats[i].fourcc == pixel_format)
+			format = &supported_formats[i];
+	}
+
+	if (WARN_ON(!format))
+		return 0;
+
+	/* HDLCD uses 'bytes per pixel', zero means 1 byte */
+	btpp = (format->bits_per_pixel + 7) / 8;
+	hdlcd_write(hdlcd, HDLCD_REG_PIXEL_FORMAT, (btpp - 1) << 3);
+
+	/*
+	 * The format of the HDLCD_REG_<color>_SELECT register is:
+	 *   - bits[23:16] - default value for that color component
+	 *   - bits[11:8]  - number of bits to extract for each color component
+	 *   - bits[4:0]   - index of the lowest bit to extract
+	 *
+	 * The default color value is used when bits[11:8] are zero, when the
+	 * pixel is outside the visible frame area or when there is a
+	 * buffer underrun.
+	 */
+	hdlcd_write(hdlcd, HDLCD_REG_RED_SELECT, format->red.offset |
+#ifdef CONFIG_DRM_HDLCD_SHOW_UNDERRUN
+		    0x00ff0000 |	/* show underruns in red */
+#endif
+		    ((format->red.length & 0xf) << 8));
+	hdlcd_write(hdlcd, HDLCD_REG_GREEN_SELECT, format->green.offset |
+		    ((format->green.length & 0xf) << 8));
+	hdlcd_write(hdlcd, HDLCD_REG_BLUE_SELECT, format->blue.offset |
+		    ((format->blue.length & 0xf) << 8));
+
+	return 0;
+}
+
+static void hdlcd_crtc_mode_set_nofb(struct drm_crtc *crtc)
+{
+	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
+	struct drm_display_mode *m = &crtc->state->adjusted_mode;
+	struct videomode vm;
+	unsigned int polarities, line_length, err;
+
+	vm.vfront_porch = m->crtc_vsync_start - m->crtc_vdisplay;
+	vm.vback_porch = m->crtc_vtotal - m->crtc_vsync_end;
+	vm.vsync_len = m->crtc_vsync_end - m->crtc_vsync_start;
+	vm.hfront_porch = m->crtc_hsync_start - m->crtc_hdisplay;
+	vm.hback_porch = m->crtc_htotal - m->crtc_hsync_end;
+	vm.hsync_len = m->crtc_hsync_end - m->crtc_hsync_start;
+
+	polarities = HDLCD_POLARITY_DATAEN | HDLCD_POLARITY_DATA;
+
+	if (m->flags & DRM_MODE_FLAG_PHSYNC)
+		polarities |= HDLCD_POLARITY_HSYNC;
+	if (m->flags & DRM_MODE_FLAG_PVSYNC)
+		polarities |= HDLCD_POLARITY_VSYNC;
+
+	line_length = crtc->primary->state->fb->pitches[0];
+
+	/* Allow max number of outstanding requests and largest burst size */
+	hdlcd_write(hdlcd, HDLCD_REG_BUS_OPTIONS,
+		    HDLCD_BUS_MAX_OUTSTAND | HDLCD_BUS_BURST_16);
+
+	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_LENGTH, line_length);
+	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_PITCH, line_length);
+	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_COUNT, m->crtc_vdisplay - 1);
+	hdlcd_write(hdlcd, HDLCD_REG_V_DATA, m->crtc_vdisplay - 1);
+	hdlcd_write(hdlcd, HDLCD_REG_V_BACK_PORCH, vm.vback_porch - 1);
+	hdlcd_write(hdlcd, HDLCD_REG_V_FRONT_PORCH, vm.vfront_porch - 1);
+	hdlcd_write(hdlcd, HDLCD_REG_V_SYNC, vm.vsync_len - 1);
+	hdlcd_write(hdlcd, HDLCD_REG_H_BACK_PORCH, vm.hback_porch - 1);
+	hdlcd_write(hdlcd, HDLCD_REG_H_FRONT_PORCH, vm.hfront_porch - 1);
+	hdlcd_write(hdlcd, HDLCD_REG_H_SYNC, vm.hsync_len - 1);
+	hdlcd_write(hdlcd, HDLCD_REG_H_DATA, m->crtc_hdisplay - 1);
+	hdlcd_write(hdlcd, HDLCD_REG_POLARITIES, polarities);
+
+	err = hdlcd_set_pxl_fmt(crtc);
+	if (err)
+		return;
+
+	clk_set_rate(hdlcd->clk, m->crtc_clock * 1000);
+}
+
+static void hdlcd_crtc_enable(struct drm_crtc *crtc)
+{
+	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
+
+	clk_prepare_enable(hdlcd->clk);
+	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 1);
+	drm_crtc_vblank_on(crtc);
+}
+
+static void hdlcd_crtc_disable(struct drm_crtc *crtc)
+{
+	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
+
+	if (!crtc->primary->fb)
+		return;
+
+	clk_disable_unprepare(hdlcd->clk);
+	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0);
+	drm_crtc_vblank_off(crtc);
+}
+
+static int hdlcd_crtc_atomic_check(struct drm_crtc *crtc,
+				   struct drm_crtc_state *state)
+{
+	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
+	struct drm_display_mode *mode = &state->adjusted_mode;
+	long rate, clk_rate = mode->clock * 1000;
+
+	rate = clk_round_rate(hdlcd->clk, clk_rate);
+	if (rate != clk_rate) {
+		/* clock required by mode not supported by hardware */
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void hdlcd_crtc_atomic_begin(struct drm_crtc *crtc,
+				    struct drm_crtc_state *state)
+{
+	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
+	unsigned long flags;
+
+	if (crtc->state->event) {
+		struct drm_pending_vblank_event *event = crtc->state->event;
+
+		crtc->state->event = NULL;
+		event->pipe = drm_crtc_index(crtc);
+
+		WARN_ON(drm_crtc_vblank_get(crtc) != 0);
+
+		spin_lock_irqsave(&crtc->dev->event_lock, flags);
+		list_add_tail(&event->base.link, &hdlcd->event_list);
+		spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
+	}
+}
+
+static void hdlcd_crtc_atomic_flush(struct drm_crtc *crtc,
+				    struct drm_crtc_state *state)
+{
+}
+
+static bool hdlcd_crtc_mode_fixup(struct drm_crtc *crtc,
+			const struct drm_display_mode *mode,
+			struct drm_display_mode *adjusted_mode)
+{
+	return true;
+}
+
+static const struct drm_crtc_helper_funcs hdlcd_crtc_helper_funcs = {
+	.mode_fixup	= hdlcd_crtc_mode_fixup,
+	.mode_set	= drm_helper_crtc_mode_set,
+	.mode_set_base	= drm_helper_crtc_mode_set_base,
+	.mode_set_nofb	= hdlcd_crtc_mode_set_nofb,
+	.enable		= hdlcd_crtc_enable,
+	.disable	= hdlcd_crtc_disable,
+	.prepare	= hdlcd_crtc_disable,
+	.commit		= hdlcd_crtc_enable,
+	.atomic_check	= hdlcd_crtc_atomic_check,
+	.atomic_begin	= hdlcd_crtc_atomic_begin,
+	.atomic_flush	= hdlcd_crtc_atomic_flush,
+};
+
+static int hdlcd_plane_atomic_check(struct drm_plane *plane,
+				    struct drm_plane_state *state)
+{
+	return 0;
+}
+
+static void hdlcd_plane_atomic_update(struct drm_plane *plane,
+				      struct drm_plane_state *state)
+{
+	struct hdlcd_drm_private *hdlcd;
+	struct drm_gem_cma_object *gem;
+	dma_addr_t scanout_start;
+
+	if (!plane->state->crtc || !plane->state->fb)
+		return;
+
+	hdlcd = crtc_to_hdlcd_priv(plane->state->crtc);
+	gem = drm_fb_cma_get_gem_obj(plane->state->fb, 0);
+	scanout_start = gem->paddr;
+	hdlcd_write(hdlcd, HDLCD_REG_FB_BASE, scanout_start);
+}
+
+static const struct drm_plane_helper_funcs hdlcd_plane_helper_funcs = {
+	.prepare_fb = NULL,
+	.cleanup_fb = NULL,
+	.atomic_check = hdlcd_plane_atomic_check,
+	.atomic_update = hdlcd_plane_atomic_update,
+};
+
+static void hdlcd_plane_destroy(struct drm_plane *plane)
+{
+	drm_plane_helper_disable(plane);
+	drm_plane_cleanup(plane);
+}
+
+static const struct drm_plane_funcs hdlcd_plane_funcs = {
+	.update_plane		= drm_atomic_helper_update_plane,
+	.disable_plane		= drm_atomic_helper_disable_plane,
+	.destroy		= hdlcd_plane_destroy,
+	.reset			= drm_atomic_helper_plane_reset,
+	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
+	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
+};
+
+static struct drm_plane *hdlcd_plane_init(struct drm_device *drm)
+{
+	struct hdlcd_drm_private *hdlcd = drm->dev_private;
+	struct drm_plane *plane = NULL;
+	u32 formats[ARRAY_SIZE(supported_formats)], i;
+	int ret;
+
+	plane = devm_kzalloc(drm->dev, sizeof(*plane), GFP_KERNEL);
+	if (!plane)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < ARRAY_SIZE(supported_formats); i++)
+		formats[i] = supported_formats[i].fourcc;
+
+	ret = drm_universal_plane_init(drm, plane, 0xff, &hdlcd_plane_funcs,
+				       formats, ARRAY_SIZE(formats),
+				       DRM_PLANE_TYPE_PRIMARY, NULL);
+	if (ret) {
+		devm_kfree(drm->dev, plane);
+		return ERR_PTR(ret);
+	}
+
+	drm_plane_helper_add(plane, &hdlcd_plane_helper_funcs);
+	hdlcd->plane = plane;
+
+	return plane;
+}
+
+void hdlcd_crtc_suspend(struct drm_crtc *crtc)
+{
+	hdlcd_crtc_disable(crtc);
+}
+
+void hdlcd_crtc_resume(struct drm_crtc *crtc)
+{
+	hdlcd_crtc_enable(crtc);
+}
+
+int hdlcd_setup_crtc(struct drm_device *drm)
+{
+	struct hdlcd_drm_private *hdlcd = drm->dev_private;
+	struct drm_plane *primary;
+	int ret;
+
+	primary = hdlcd_plane_init(drm);
+	if (IS_ERR(primary))
+		return PTR_ERR(primary);
+
+	ret = drm_crtc_init_with_planes(drm, &hdlcd->crtc, primary, NULL,
+					&hdlcd_crtc_funcs, NULL);
+	if (ret) {
+		hdlcd_plane_destroy(primary);
+		devm_kfree(drm->dev, primary);
+		return ret;
+	}
+
+	drm_crtc_helper_add(&hdlcd->crtc, &hdlcd_crtc_helper_funcs);
+	return 0;
+}