drm/tilcdc: add TI LCD Controller DRM driver (v4)

A simple DRM/KMS driver for the TI LCD Controller found in various
smaller TI parts (AM33xx, OMAPL138, etc).  This driver uses the
CMA helpers.  Currently only the TFP410 DVI encoder is supported
(tested with beaglebone + DVI cape).  There are also various LCD
displays, for which support can be added (as I get hw to test on),
and an external i2c HDMI encoder found on some boards.

The display controller supports a single CRTC.  And the encoder+
connector are split out into sub-devices.  Depending on which LCD
or external encoder is actually present, the appropriate output
module(s) will be loaded.

v1: original
v2: fix fb refcnting and few other cleanups
v3: get +/- vsync/hsync from timings rather than panel-info, add
    option DT max-bandwidth field so driver doesn't attempt to
    pick a display mode with too high memory bandwidth, and other
    small cleanups
v4: remove some unneeded stuff from panel-info struct, properly
    set high bits for hfp/hsw/hbp for rev 2, add DT bindings docs
Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Tested-by: Koen Kooi <koen@dominion.thruhere.net>

Documentation/devicetree/bindings/drm/tilcdc/tfp410.txt

+Device-Tree bindings for tilcdc DRM TFP410 output driver
+
+Required properties:
+ - compatible: value should be "ti,tilcdc,tfp410".
+ - i2c: the phandle for the i2c device to use for DDC
+
+Recommended properties:
+ - pinctrl-names, pinctrl-0: the pincontrol settings to configure
+   muxing properly for pins that connect to TFP410 device
+ - powerdn-gpio: the powerdown GPIO, pulled low to power down the
+   TFP410 device (for DPMS_OFF)
+
+Example:
+
+	dvicape {
+		compatible = "ti,tilcdc,tfp410";
+		i2c = <&i2c2>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&bone_dvi_cape_dvi_00A1_pins>;
+		powerdn-gpio = <&gpio2 31 0>;
+	};

Documentation/devicetree/bindings/drm/tilcdc/tilcdc.txt

+Device-Tree bindings for tilcdc DRM driver
+
+Required properties:
+ - compatible: value should be "ti,am33xx-tilcdc".
+ - interrupts: the interrupt number
+ - reg: base address and size of the LCDC device
+
+Recommended properties:
+ - interrupt-parent: the phandle for the interrupt controller that
+   services interrupts for this device.
+ - ti,hwmods: Name of the hwmod associated to the LCDC
+
+Example:
+
+	fb: fb@4830e000 {
+		compatible = "ti,am33xx-tilcdc";
+		reg = <0x4830e000 0x1000>;
+		interrupt-parent = <&intc>;
+		interrupts = <36>;
+		ti,hwmods = "lcdc";
+	};

drivers/gpu/drm/Kconfig

@@ -215,3 +215,5 @@ source "drivers/gpu/drm/cirrus/Kconfig"
 source "drivers/gpu/drm/shmobile/Kconfig"
 
 source "drivers/gpu/drm/tegra/Kconfig"
+
+source "drivers/gpu/drm/tilcdc/Kconfig"

drivers/gpu/drm/Makefile

@@ -50,4 +50,5 @@ obj-$(CONFIG_DRM_UDL) += udl/
 obj-$(CONFIG_DRM_AST) += ast/
 obj-$(CONFIG_DRM_SHMOBILE) +=shmobile/
 obj-$(CONFIG_DRM_TEGRA) += tegra/
+obj-$(CONFIG_DRM_TILCDC)	+= tilcdc/
 obj-y			+= i2c/

drivers/gpu/drm/tilcdc/Kconfig

+config DRM_TILCDC
+	tristate "DRM Support for TI LCDC Display Controller"
+	depends on DRM && OF
+	select DRM_KMS_HELPER
+	select DRM_KMS_CMA_HELPER
+	select DRM_GEM_CMA_HELPER
+	help
+	  Choose this option if you have an TI SoC with LCDC display
+	  controller, for example AM33xx in beagle-bone, DA8xx, or
+	  OMAP-L1xx.  This driver replaces the FB_DA8XX fbdev driver.

drivers/gpu/drm/tilcdc/Makefile

+ccflags-y := -Iinclude/drm -Werror
+
+tilcdc-y := \
+	tilcdc_crtc.o \
+	tilcdc_tfp410.o \
+	tilcdc_drv.o
+
+obj-$(CONFIG_DRM_TILCDC)	+= tilcdc.o

drivers/gpu/drm/tilcdc/tilcdc_crtc.c

+/*
+ * Copyright (C) 2012 Texas Instruments
+ * Author: Rob Clark <robdclark@gmail.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/kfifo.h>
+
+#include "tilcdc_drv.h"
+#include "tilcdc_regs.h"
+
+struct tilcdc_crtc {
+	struct drm_crtc base;
+
+	const struct tilcdc_panel_info *info;
+	uint32_t dirty;
+	dma_addr_t start, end;
+	struct drm_pending_vblank_event *event;
+	int dpms;
+	wait_queue_head_t frame_done_wq;
+	bool frame_done;
+
+	/* fb currently set to scanout 0/1: */
+	struct drm_framebuffer *scanout[2];
+
+	/* for deferred fb unref's: */
+	DECLARE_KFIFO_PTR(unref_fifo, struct drm_framebuffer *);
+	struct work_struct work;
+};
+#define to_tilcdc_crtc(x) container_of(x, struct tilcdc_crtc, base)
+
+static void unref_worker(struct work_struct *work)
+{
+	struct tilcdc_crtc *tilcdc_crtc = container_of(work, struct tilcdc_crtc, work);
+	struct drm_device *dev = tilcdc_crtc->base.dev;
+	struct drm_framebuffer *fb;
+
+	mutex_lock(&dev->mode_config.mutex);
+	while (kfifo_get(&tilcdc_crtc->unref_fifo, &fb))
+		drm_framebuffer_unreference(fb);
+	mutex_unlock(&dev->mode_config.mutex);
+}
+
+static void set_scanout(struct drm_crtc *crtc, int n)
+{
+	static const uint32_t base_reg[] = {
+			LCDC_DMA_FB_BASE_ADDR_0_REG, LCDC_DMA_FB_BASE_ADDR_1_REG,
+	};
+	static const uint32_t ceil_reg[] = {
+			LCDC_DMA_FB_CEILING_ADDR_0_REG, LCDC_DMA_FB_CEILING_ADDR_1_REG,
+	};
+	static const uint32_t stat[] = {
+			LCDC_END_OF_FRAME0, LCDC_END_OF_FRAME1,
+	};
+	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
+	struct drm_device *dev = crtc->dev;
+
+	pm_runtime_get_sync(dev->dev);
+	tilcdc_write(dev, base_reg[n], tilcdc_crtc->start);
+	tilcdc_write(dev, ceil_reg[n], tilcdc_crtc->end);
+	if (tilcdc_crtc->scanout[n]) {
+		if (kfifo_put(&tilcdc_crtc->unref_fifo,
+				(const struct drm_framebuffer **)&tilcdc_crtc->scanout[n])) {
+			struct tilcdc_drm_private *priv = dev->dev_private;
+			queue_work(priv->wq, &tilcdc_crtc->work);
+		} else {
+			dev_err(dev->dev, "unref fifo full!\n");
+			drm_framebuffer_unreference(tilcdc_crtc->scanout[n]);
+		}
+	}
+	tilcdc_crtc->scanout[n] = crtc->fb;
+	drm_framebuffer_reference(tilcdc_crtc->scanout[n]);
+	tilcdc_crtc->dirty &= ~stat[n];
+	pm_runtime_put_sync(dev->dev);
+}
+
+static void update_scanout(struct drm_crtc *crtc)
+{
+	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
+	struct drm_device *dev = crtc->dev;
+	struct drm_framebuffer *fb = crtc->fb;
+	struct drm_gem_cma_object *gem;
+	unsigned int depth, bpp;
+
+	drm_fb_get_bpp_depth(fb->pixel_format, &depth, &bpp);
+	gem = drm_fb_cma_get_gem_obj(fb, 0);
+
+	tilcdc_crtc->start = gem->paddr + fb->offsets[0] +
+			(crtc->y * fb->pitches[0]) + (crtc->x * bpp/8);
+
+	tilcdc_crtc->end = tilcdc_crtc->start +
+			(crtc->mode.vdisplay * fb->pitches[0]);
+
+	if (tilcdc_crtc->dpms == DRM_MODE_DPMS_ON) {
+		/* already enabled, so just mark the frames that need
+		 * updating and they will be updated on vblank:
+		 */
+		tilcdc_crtc->dirty |= LCDC_END_OF_FRAME0 | LCDC_END_OF_FRAME1;
+		drm_vblank_get(dev, 0);
+	} else {
+		/* not enabled yet, so update registers immediately: */
+		set_scanout(crtc, 0);
+		set_scanout(crtc, 1);
+	}
+}
+
+static void start(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct tilcdc_drm_private *priv = dev->dev_private;
+
+	if (priv->rev == 2) {
+		tilcdc_set(dev, LCDC_CLK_RESET_REG, LCDC_CLK_MAIN_RESET);
+		msleep(1);
+		tilcdc_clear(dev, LCDC_CLK_RESET_REG, LCDC_CLK_MAIN_RESET);
+		msleep(1);
+	}
+
+	tilcdc_set(dev, LCDC_DMA_CTRL_REG, LCDC_DUAL_FRAME_BUFFER_ENABLE);
+	tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_PALETTE_LOAD_MODE(DATA_ONLY));
+	tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
+}
+
+static void stop(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+
+	tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
+}
+
+static void tilcdc_crtc_destroy(struct drm_crtc *crtc)
+{
+	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
+
+	WARN_ON(tilcdc_crtc->dpms == DRM_MODE_DPMS_ON);
+
+	drm_crtc_cleanup(crtc);
+	WARN_ON(!kfifo_is_empty(&tilcdc_crtc->unref_fifo));
+	kfifo_free(&tilcdc_crtc->unref_fifo);
+	kfree(tilcdc_crtc);
+}
+
+static int tilcdc_crtc_page_flip(struct drm_crtc *crtc,
+		struct drm_framebuffer *fb,
+		struct drm_pending_vblank_event *event)
+{
+	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
+	struct drm_device *dev = crtc->dev;
+
+	if (tilcdc_crtc->event) {
+		dev_err(dev->dev, "already pending page flip!\n");
+		return -EBUSY;
+	}
+
+	crtc->fb = fb;
+	tilcdc_crtc->event = event;
+	update_scanout(crtc);
+
+	return 0;
+}
+
+static void tilcdc_crtc_dpms(struct drm_crtc *crtc, int mode)
+{
+	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
+	struct drm_device *dev = crtc->dev;
+	struct tilcdc_drm_private *priv = dev->dev_private;
+
+	/* we really only care about on or off: */
+	if (mode != DRM_MODE_DPMS_ON)
+		mode = DRM_MODE_DPMS_OFF;
+
+	if (tilcdc_crtc->dpms == mode)
+		return;
+
+	tilcdc_crtc->dpms = mode;
+
+	pm_runtime_get_sync(dev->dev);
+
+	if (mode == DRM_MODE_DPMS_ON) {
+		pm_runtime_forbid(dev->dev);
+		start(crtc);
+	} else {
+		tilcdc_crtc->frame_done = false;
+		stop(crtc);
+
+		/* if necessary wait for framedone irq which will still come
+		 * before putting things to sleep..
+		 */
+		if (priv->rev == 2) {
+			int ret = wait_event_timeout(
+					tilcdc_crtc->frame_done_wq,
+					tilcdc_crtc->frame_done,
+					msecs_to_jiffies(50));
+			if (ret == 0)
+				dev_err(dev->dev, "timeout waiting for framedone\n");
+		}
+		pm_runtime_allow(dev->dev);
+	}
+
+	pm_runtime_put_sync(dev->dev);
+}
+
+static bool tilcdc_crtc_mode_fixup(struct drm_crtc *crtc,
+		const struct drm_display_mode *mode,
+		struct drm_display_mode *adjusted_mode)
+{
+	return true;
+}
+
+static void tilcdc_crtc_prepare(struct drm_crtc *crtc)
+{
+	tilcdc_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
+}
+
+static void tilcdc_crtc_commit(struct drm_crtc *crtc)
+{
+	tilcdc_crtc_dpms(crtc, DRM_MODE_DPMS_ON);
+}
+
+static int tilcdc_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 tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
+	struct drm_device *dev = crtc->dev;
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	const struct tilcdc_panel_info *info = tilcdc_crtc->info;
+	uint32_t reg, hbp, hfp, hsw, vbp, vfp, vsw;
+	int ret;
+
+	ret = tilcdc_crtc_mode_valid(crtc, mode);
+	if (WARN_ON(ret))
+		return ret;
+
+	if (WARN_ON(!info))
+		return -EINVAL;
+
+	pm_runtime_get_sync(dev->dev);
+
+	/* Configure the Burst Size and fifo threshold of DMA: */
+	reg = tilcdc_read(dev, LCDC_DMA_CTRL_REG) & ~0x00000770;
+	switch (info->dma_burst_sz) {
+	case 1:
+		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_1);
+		break;
+	case 2:
+		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_2);
+		break;
+	case 4:
+		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_4);
+		break;
+	case 8:
+		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_8);
+		break;
+	case 16:
+		reg |= LCDC_DMA_BURST_SIZE(LCDC_DMA_BURST_16);
+		break;
+	default:
+		return -EINVAL;
+	}
+	reg |= (info->fifo_th << 8);
+	tilcdc_write(dev, LCDC_DMA_CTRL_REG, reg);
+
+	/* Configure timings: */
+	hbp = mode->htotal - mode->hsync_end;
+	hfp = mode->hsync_start - mode->hdisplay;
+	hsw = mode->hsync_end - mode->hsync_start;
+	vbp = mode->vtotal - mode->vsync_end;
+	vfp = mode->vsync_start - mode->vdisplay;
+	vsw = mode->vsync_end - mode->vsync_start;
+
+	DBG("%dx%d, hbp=%u, hfp=%u, hsw=%u, vbp=%u, vfp=%u, vsw=%u",
+			mode->hdisplay, mode->vdisplay, hbp, hfp, hsw, vbp, vfp, vsw);
+
+	/* Configure the AC Bias Period and Number of Transitions per Interrupt: */
+	reg = tilcdc_read(dev, LCDC_RASTER_TIMING_2_REG) & ~0x000fff00;
+	reg |= LCDC_AC_BIAS_FREQUENCY(info->ac_bias) |
+		LCDC_AC_BIAS_TRANSITIONS_PER_INT(info->ac_bias_intrpt);
+	if (priv->rev == 2) {
+		reg |= (hfp & 0x300) >> 8;
+		reg |= (hbp & 0x300) >> 4;
+		reg |= (hsw & 0x3c0) << 21;
+	}
+	tilcdc_write(dev, LCDC_RASTER_TIMING_2_REG, reg);
+
+	reg = (((mode->hdisplay >> 4) - 1) << 4) |
+		((hbp & 0xff) << 24) |
+		((hfp & 0xff) << 16) |
+		((hsw & 0x3f) << 10);
+	if (priv->rev == 2)
+		reg |= (((mode->hdisplay >> 4) - 1) & 0x40) >> 3;
+	tilcdc_write(dev, LCDC_RASTER_TIMING_0_REG, reg);
+
+	reg = ((mode->vdisplay - 1) & 0x3ff) |
+		((vbp & 0xff) << 24) |
+		((vfp & 0xff) << 16) |
+		((vsw & 0x3f) << 10);
+	tilcdc_write(dev, LCDC_RASTER_TIMING_1_REG, reg);
+
+	/* Configure display type: */
+	reg = tilcdc_read(dev, LCDC_RASTER_CTRL_REG) &
+		~(LCDC_TFT_MODE | LCDC_MONO_8BIT_MODE | LCDC_MONOCHROME_MODE |
+			LCDC_V2_TFT_24BPP_MODE | LCDC_V2_TFT_24BPP_UNPACK | 0x000ff000);
+	reg |= LCDC_TFT_MODE; /* no monochrome/passive support */
+	if (info->tft_alt_mode)
+		reg |= LCDC_TFT_ALT_ENABLE;
+	if (priv->rev == 2) {
+		unsigned int depth, bpp;
+
+		drm_fb_get_bpp_depth(crtc->fb->pixel_format, &depth, &bpp);
+		switch (bpp) {
+		case 16:
+			break;
+		case 32:
+			reg |= LCDC_V2_TFT_24BPP_UNPACK;
+			/* fallthrough */
+		case 24:
+			reg |= LCDC_V2_TFT_24BPP_MODE;
+			break;
+		default:
+			dev_err(dev->dev, "invalid pixel format\n");
+			return -EINVAL;
+		}
+	}
+	reg |= info->fdd < 12;
+	tilcdc_write(dev, LCDC_RASTER_CTRL_REG, reg);
+
+	if (info->invert_pxl_clk)
+		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_PIXEL_CLOCK);
+	else
+		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_PIXEL_CLOCK);
+
+	if (info->sync_ctrl)
+		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_CTRL);
+	else
+		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_CTRL);
+
+	if (info->sync_edge)
+		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_EDGE);
+	else
+		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_SYNC_EDGE);
+
+	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
+		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_HSYNC);
+	else
+		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_HSYNC);
+
+	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
+		tilcdc_set(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_VSYNC);
+	else
+		tilcdc_clear(dev, LCDC_RASTER_TIMING_2_REG, LCDC_INVERT_VSYNC);
+
+	if (info->raster_order)
+		tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ORDER);
+	else
+		tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ORDER);
+
+
+	update_scanout(crtc);
+	tilcdc_crtc_update_clk(crtc);
+
+	pm_runtime_put_sync(dev->dev);
+
+	return 0;
+}
+
+static int tilcdc_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y,
+		struct drm_framebuffer *old_fb)
+{
+	update_scanout(crtc);
+	return 0;
+}
+
+static void tilcdc_crtc_load_lut(struct drm_crtc *crtc)
+{
+}
+
+static const struct drm_crtc_funcs tilcdc_crtc_funcs = {
+		.destroy        = tilcdc_crtc_destroy,
+		.set_config     = drm_crtc_helper_set_config,
+		.page_flip      = tilcdc_crtc_page_flip,
+};
+
+static const struct drm_crtc_helper_funcs tilcdc_crtc_helper_funcs = {
+		.dpms           = tilcdc_crtc_dpms,
+		.mode_fixup     = tilcdc_crtc_mode_fixup,
+		.prepare        = tilcdc_crtc_prepare,
+		.commit         = tilcdc_crtc_commit,
+		.mode_set       = tilcdc_crtc_mode_set,
+		.mode_set_base  = tilcdc_crtc_mode_set_base,
+		.load_lut       = tilcdc_crtc_load_lut,
+};
+
+int tilcdc_crtc_max_width(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	int max_width = 0;
+
+	if (priv->rev == 1)
+		max_width = 1024;
+	else if (priv->rev == 2)
+		max_width = 2048;
+
+	return max_width;
+}
+
+int tilcdc_crtc_mode_valid(struct drm_crtc *crtc, struct drm_display_mode *mode)
+{
+	struct tilcdc_drm_private *priv = crtc->dev->dev_private;
+	unsigned int bandwidth;
+
+	if (mode->hdisplay > tilcdc_crtc_max_width(crtc))
+		return MODE_VIRTUAL_X;
+
+	/* width must be multiple of 16 */
+	if (mode->hdisplay & 0xf)
+		return MODE_VIRTUAL_X;
+
+	if (mode->vdisplay > 2048)
+		return MODE_VIRTUAL_Y;
+
+	/* filter out modes that would require too much memory bandwidth: */
+	bandwidth = mode->hdisplay * mode->vdisplay * drm_mode_vrefresh(mode);
+	if (bandwidth > priv->max_bandwidth)
+		return MODE_BAD;
+
+	return MODE_OK;
+}
+
+void tilcdc_crtc_set_panel_info(struct drm_crtc *crtc,
+		const struct tilcdc_panel_info *info)
+{
+	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
+	tilcdc_crtc->info = info;
+}
+
+void tilcdc_crtc_update_clk(struct drm_crtc *crtc)
+{
+	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
+	struct drm_device *dev = crtc->dev;
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	int dpms = tilcdc_crtc->dpms;
+	unsigned int lcd_clk, div;
+	int ret;
+
+	pm_runtime_get_sync(dev->dev);
+
+	if (dpms == DRM_MODE_DPMS_ON)
+		tilcdc_crtc_dpms(crtc, DRM_MODE_DPMS_OFF);
+
+	/* in raster mode, minimum divisor is 2: */
+	ret = clk_set_rate(priv->disp_clk, crtc->mode.clock * 1000 * 2);
+	if (ret) {
+		dev_err(dev->dev, "failed to set display clock rate to: %d\n",
+				crtc->mode.clock);
+		goto out;
+	}
+
+	lcd_clk = clk_get_rate(priv->clk);
+	div = lcd_clk / (crtc->mode.clock * 1000);
+
+	DBG("lcd_clk=%u, mode clock=%d, div=%u", lcd_clk, crtc->mode.clock, div);
+	DBG("fck=%lu, dpll_disp_ck=%lu", clk_get_rate(priv->clk), clk_get_rate(priv->disp_clk));
+
+	/* Configure the LCD clock divisor. */
+	tilcdc_write(dev, LCDC_CTRL_REG, LCDC_CLK_DIVISOR(div) |
+			LCDC_RASTER_MODE);
+
+	if (priv->rev == 2)
+		tilcdc_set(dev, LCDC_CLK_ENABLE_REG,
+				LCDC_V2_DMA_CLK_EN | LCDC_V2_LIDD_CLK_EN |
+				LCDC_V2_CORE_CLK_EN);
+
+	if (dpms == DRM_MODE_DPMS_ON)
+		tilcdc_crtc_dpms(crtc, DRM_MODE_DPMS_ON);
+
+out:
+	pm_runtime_put_sync(dev->dev);
+}
+
+irqreturn_t tilcdc_crtc_irq(struct drm_crtc *crtc)
+{
+	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
+	struct drm_device *dev = crtc->dev;
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	uint32_t stat = tilcdc_read_irqstatus(dev);
+
+	if ((stat & LCDC_SYNC_LOST) && (stat & LCDC_FIFO_UNDERFLOW)) {
+		stop(crtc);
+		dev_err(dev->dev, "error: %08x\n", stat);
+		tilcdc_clear_irqstatus(dev, stat);
+		start(crtc);
+	} else if (stat & LCDC_PL_LOAD_DONE) {
+		tilcdc_clear_irqstatus(dev, stat);
+	} else {
+		struct drm_pending_vblank_event *event;
+		unsigned long flags;
+		uint32_t dirty = tilcdc_crtc->dirty & stat;
+
+		tilcdc_clear_irqstatus(dev, stat);
+
+		if (dirty & LCDC_END_OF_FRAME0)
+			set_scanout(crtc, 0);
+
+		if (dirty & LCDC_END_OF_FRAME1)
+			set_scanout(crtc, 1);
+
+		drm_handle_vblank(dev, 0);
+
+		spin_lock_irqsave(&dev->event_lock, flags);
+		event = tilcdc_crtc->event;
+		tilcdc_crtc->event = NULL;
+		if (event)
+			drm_send_vblank_event(dev, 0, event);
+		spin_unlock_irqrestore(&dev->event_lock, flags);
+
+		if (dirty && !tilcdc_crtc->dirty)
+			drm_vblank_put(dev, 0);
+	}
+
+	if (priv->rev == 2) {
+		if (stat & LCDC_FRAME_DONE) {
+			tilcdc_crtc->frame_done = true;
+			wake_up(&tilcdc_crtc->frame_done_wq);
+		}
+		tilcdc_write(dev, LCDC_END_OF_INT_IND_REG, 0);
+	}
+
+	return IRQ_HANDLED;
+}
+
+void tilcdc_crtc_cancel_page_flip(struct drm_crtc *crtc, struct drm_file *file)
+{
+	struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
+	struct drm_pending_vblank_event *event;
+	struct drm_device *dev = crtc->dev;
+	unsigned long flags;
+
+	/* Destroy the pending vertical blanking event associated with the
+	 * pending page flip, if any, and disable vertical blanking interrupts.
+	 */
+	spin_lock_irqsave(&dev->event_lock, flags);
+	event = tilcdc_crtc->event;
+	if (event && event->base.file_priv == file) {
+		tilcdc_crtc->event = NULL;
+		event->base.destroy(&event->base);
+		drm_vblank_put(dev, 0);
+	}
+	spin_unlock_irqrestore(&dev->event_lock, flags);
+}
+
+struct drm_crtc *tilcdc_crtc_create(struct drm_device *dev)
+{
+	struct tilcdc_crtc *tilcdc_crtc;
+	struct drm_crtc *crtc;
+	int ret;
+
+	tilcdc_crtc = kzalloc(sizeof(*tilcdc_crtc), GFP_KERNEL);
+	if (!tilcdc_crtc) {
+		dev_err(dev->dev, "allocation failed\n");
+		return NULL;
+	}
+
+	crtc = &tilcdc_crtc->base;
+
+	tilcdc_crtc->dpms = DRM_MODE_DPMS_OFF;
+	init_waitqueue_head(&tilcdc_crtc->frame_done_wq);
+
+	ret = kfifo_alloc(&tilcdc_crtc->unref_fifo, 16, GFP_KERNEL);
+	if (ret) {
+		dev_err(dev->dev, "could not allocate unref FIFO\n");
+		goto fail;
+	}
+
+	INIT_WORK(&tilcdc_crtc->work, unref_worker);
+
+	ret = drm_crtc_init(dev, crtc, &tilcdc_crtc_funcs);
+	if (ret < 0)
+		goto fail;
+
+	drm_crtc_helper_add(crtc, &tilcdc_crtc_helper_funcs);
+
+	return crtc;
+
+fail:
+	tilcdc_crtc_destroy(crtc);
+	return NULL;
+}

drivers/gpu/drm/tilcdc/tilcdc_drv.c

+/*
+ * Copyright (C) 2012 Texas Instruments
+ * Author: Rob Clark <robdclark@gmail.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/>.
+ */
+
+/* LCDC DRM driver, based on da8xx-fb */
+
+#include "tilcdc_drv.h"
+#include "tilcdc_regs.h"
+#include "tilcdc_tfp410.h"
+
+#include "drm_fb_helper.h"
+
+static LIST_HEAD(module_list);
+
+void tilcdc_module_init(struct tilcdc_module *mod, const char *name,
+		const struct tilcdc_module_ops *funcs)
+{
+	mod->name = name;
+	mod->funcs = funcs;
+	INIT_LIST_HEAD(&mod->list);
+	list_add(&mod->list, &module_list);
+}
+
+void tilcdc_module_cleanup(struct tilcdc_module *mod)
+{
+	list_del(&mod->list);
+}
+
+static struct of_device_id tilcdc_of_match[];
+
+static struct drm_framebuffer *tilcdc_fb_create(struct drm_device *dev,
+		struct drm_file *file_priv, struct drm_mode_fb_cmd2 *mode_cmd)
+{
+	return drm_fb_cma_create(dev, file_priv, mode_cmd);
+}
+
+static void tilcdc_fb_output_poll_changed(struct drm_device *dev)
+{
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	if (priv->fbdev)
+		drm_fbdev_cma_hotplug_event(priv->fbdev);
+}
+
+static const struct drm_mode_config_funcs mode_config_funcs = {
+	.fb_create = tilcdc_fb_create,
+	.output_poll_changed = tilcdc_fb_output_poll_changed,
+};
+
+static int modeset_init(struct drm_device *dev)
+{
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	struct tilcdc_module *mod;
+
+	drm_mode_config_init(dev);
+
+	priv->crtc = tilcdc_crtc_create(dev);
+
+	list_for_each_entry(mod, &module_list, list) {
+		DBG("loading module: %s", mod->name);
+		mod->funcs->modeset_init(mod, dev);
+	}
+
+	if ((priv->num_encoders = 0) || (priv->num_connectors == 0)) {
+		/* oh nos! */
+		dev_err(dev->dev, "no encoders/connectors found\n");
+		return -ENXIO;
+	}
+
+	dev->mode_config.min_width = 0;
+	dev->mode_config.min_height = 0;
+	dev->mode_config.max_width = tilcdc_crtc_max_width(priv->crtc);
+	dev->mode_config.max_height = 2048;
+	dev->mode_config.funcs = &mode_config_funcs;
+
+	return 0;
+}
+
+#ifdef CONFIG_CPU_FREQ
+static int cpufreq_transition(struct notifier_block *nb,
+				     unsigned long val, void *data)
+{
+	struct tilcdc_drm_private *priv = container_of(nb,
+			struct tilcdc_drm_private, freq_transition);
+	if (val == CPUFREQ_POSTCHANGE) {
+		if (priv->lcd_fck_rate != clk_get_rate(priv->clk)) {
+			priv->lcd_fck_rate = clk_get_rate(priv->clk);
+			tilcdc_crtc_update_clk(priv->crtc);
+		}
+	}
+
+	return 0;
+}
+#endif
+
+/*
+ * DRM operations:
+ */
+
+static int tilcdc_unload(struct drm_device *dev)
+{
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	struct tilcdc_module *mod, *cur;
+
+	drm_kms_helper_poll_fini(dev);
+	drm_mode_config_cleanup(dev);
+	drm_vblank_cleanup(dev);
+
+	pm_runtime_get_sync(dev->dev);
+	drm_irq_uninstall(dev);
+	pm_runtime_put_sync(dev->dev);
+
+#ifdef CONFIG_CPU_FREQ
+	cpufreq_unregister_notifier(&priv->freq_transition,
+			CPUFREQ_TRANSITION_NOTIFIER);
+#endif
+
+	if (priv->clk)
+		clk_put(priv->clk);
+
+	if (priv->mmio)
+		iounmap(priv->mmio);
+
+	flush_workqueue(priv->wq);
+	destroy_workqueue(priv->wq);
+
+	dev->dev_private = NULL;
+
+	pm_runtime_disable(dev->dev);
+
+	list_for_each_entry_safe(mod, cur, &module_list, list) {
+		DBG("destroying module: %s", mod->name);
+		mod->funcs->destroy(mod);
+	}
+
+	kfree(priv);
+
+	return 0;
+}
+
+static int tilcdc_load(struct drm_device *dev, unsigned long flags)
+{
+	struct platform_device *pdev = dev->platformdev;
+	struct device_node *node = pdev->dev.of_node;
+	struct tilcdc_drm_private *priv;
+	struct resource *res;
+	int ret;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv) {
+		dev_err(dev->dev, "failed to allocate private data\n");
+		return -ENOMEM;
+	}
+
+	dev->dev_private = priv;
+
+	priv->wq = alloc_ordered_workqueue("tilcdc", 0);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev->dev, "failed to get memory resource\n");
+		ret = -EINVAL;
+		goto fail;
+	}
+
+	priv->mmio = ioremap_nocache(res->start, resource_size(res));
+	if (!priv->mmio) {
+		dev_err(dev->dev, "failed to ioremap\n");
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	priv->clk = clk_get(dev->dev, "fck");
+	if (IS_ERR(priv->clk)) {
+		dev_err(dev->dev, "failed to get functional clock\n");
+		ret = -ENODEV;
+		goto fail;
+	}
+
+	priv->disp_clk = clk_get(dev->dev, "dpll_disp_ck");
+	if (IS_ERR(priv->clk)) {
+		dev_err(dev->dev, "failed to get display clock\n");
+		ret = -ENODEV;
+		goto fail;
+	}
+
+#ifdef CONFIG_CPU_FREQ
+	priv->lcd_fck_rate = clk_get_rate(priv->clk);
+	priv->freq_transition.notifier_call = cpufreq_transition;
+	ret = cpufreq_register_notifier(&priv->freq_transition,
+			CPUFREQ_TRANSITION_NOTIFIER);
+	if (ret) {
+		dev_err(dev->dev, "failed to register cpufreq notifier\n");
+		goto fail;
+	}
+#endif
+
+	if (of_property_read_u32(node, "max-bandwidth", &priv->max_bandwidth))
+		priv->max_bandwidth = 1280 * 1024 * 60;
+
+	pm_runtime_enable(dev->dev);
+
+	/* Determine LCD IP Version */
+	pm_runtime_get_sync(dev->dev);
+	switch (tilcdc_read(dev, LCDC_PID_REG)) {
+	case 0x4c100102:
+		priv->rev = 1;
+		break;
+	case 0x4f200800:
+	case 0x4f201000:
+		priv->rev = 2;
+		break;
+	default:
+		dev_warn(dev->dev, "Unknown PID Reg value 0x%08x, "
+				"defaulting to LCD revision 1\n",
+				tilcdc_read(dev, LCDC_PID_REG));
+		priv->rev = 1;
+		break;
+	}
+
+	pm_runtime_put_sync(dev->dev);
+
+	ret = modeset_init(dev);
+	if (ret < 0) {
+		dev_err(dev->dev, "failed to initialize mode setting\n");
+		goto fail;
+	}
+
+	ret = drm_vblank_init(dev, 1);
+	if (ret < 0) {
+		dev_err(dev->dev, "failed to initialize vblank\n");
+		goto fail;
+	}
+
+	pm_runtime_get_sync(dev->dev);
+	ret = drm_irq_install(dev);
+	pm_runtime_put_sync(dev->dev);
+	if (ret < 0) {
+		dev_err(dev->dev, "failed to install IRQ handler\n");
+		goto fail;
+	}
+
+	platform_set_drvdata(pdev, dev);
+
+	priv->fbdev = drm_fbdev_cma_init(dev, 16,
+			dev->mode_config.num_crtc,
+			dev->mode_config.num_connector);
+
+	drm_kms_helper_poll_init(dev);
+
+	return 0;
+
+fail:
+	tilcdc_unload(dev);
+	return ret;
+}
+
+static void tilcdc_preclose(struct drm_device *dev, struct drm_file *file)
+{
+	struct tilcdc_drm_private *priv = dev->dev_private;
+
+	tilcdc_crtc_cancel_page_flip(priv->crtc, file);
+}
+
+static void tilcdc_lastclose(struct drm_device *dev)
+{
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	drm_fbdev_cma_restore_mode(priv->fbdev);
+}
+
+static irqreturn_t tilcdc_irq(DRM_IRQ_ARGS)
+{
+	struct drm_device *dev = arg;
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	return tilcdc_crtc_irq(priv->crtc);
+}
+
+static void tilcdc_irq_preinstall(struct drm_device *dev)
+{
+	tilcdc_clear_irqstatus(dev, 0xffffffff);
+}
+
+static int tilcdc_irq_postinstall(struct drm_device *dev)
+{
+	struct tilcdc_drm_private *priv = dev->dev_private;
+
+	/* enable FIFO underflow irq: */
+	if (priv->rev == 1) {
+		tilcdc_set(dev, LCDC_RASTER_CTRL_REG, LCDC_V1_UNDERFLOW_INT_ENA);
+	} else {
+		tilcdc_set(dev, LCDC_INT_ENABLE_SET_REG, LCDC_V2_UNDERFLOW_INT_ENA);
+	}
+
+	return 0;
+}
+
+static void tilcdc_irq_uninstall(struct drm_device *dev)
+{
+	struct tilcdc_drm_private *priv = dev->dev_private;
+
+	/* disable irqs that we might have enabled: */
+	if (priv->rev == 1) {
+		tilcdc_clear(dev, LCDC_RASTER_CTRL_REG,
+				LCDC_V1_UNDERFLOW_INT_ENA | LCDC_V1_PL_INT_ENA);
+		tilcdc_clear(dev, LCDC_DMA_CTRL_REG, LCDC_V1_END_OF_FRAME_INT_ENA);
+	} else {
+		tilcdc_clear(dev, LCDC_INT_ENABLE_SET_REG,
+			LCDC_V2_UNDERFLOW_INT_ENA | LCDC_V2_PL_INT_ENA |
+			LCDC_V2_END_OF_FRAME0_INT_ENA | LCDC_V2_END_OF_FRAME1_INT_ENA |
+			LCDC_FRAME_DONE);
+	}
+
+}
+
+static void enable_vblank(struct drm_device *dev, bool enable)
+{
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	u32 reg, mask;
+
+	if (priv->rev == 1) {
+		reg = LCDC_DMA_CTRL_REG;
+		mask = LCDC_V1_END_OF_FRAME_INT_ENA;
+	} else {
+		reg = LCDC_INT_ENABLE_SET_REG;
+		mask = LCDC_V2_END_OF_FRAME0_INT_ENA |
+			LCDC_V2_END_OF_FRAME1_INT_ENA | LCDC_FRAME_DONE;
+	}
+
+	if (enable)
+		tilcdc_set(dev, reg, mask);
+	else
+		tilcdc_clear(dev, reg, mask);
+}
+
+static int tilcdc_enable_vblank(struct drm_device *dev, int crtc)
+{
+	enable_vblank(dev, true);
+	return 0;
+}
+
+static void tilcdc_disable_vblank(struct drm_device *dev, int crtc)
+{
+	enable_vblank(dev, false);
+}
+
+#if defined(CONFIG_DEBUG_FS) || defined(CONFIG_PM_SLEEP)
+static const struct {
+	const char *name;
+	uint8_t  rev;
+	uint8_t  save;
+	uint32_t reg;
+} registers[] = 	{
+#define REG(rev, save, reg) { #reg, rev, save, reg }
+		/* exists in revision 1: */
+		REG(1, false, LCDC_PID_REG),
+		REG(1, true,  LCDC_CTRL_REG),
+		REG(1, false, LCDC_STAT_REG),
+		REG(1, true,  LCDC_RASTER_CTRL_REG),
+		REG(1, true,  LCDC_RASTER_TIMING_0_REG),
+		REG(1, true,  LCDC_RASTER_TIMING_1_REG),
+		REG(1, true,  LCDC_RASTER_TIMING_2_REG),
+		REG(1, true,  LCDC_DMA_CTRL_REG),
+		REG(1, true,  LCDC_DMA_FB_BASE_ADDR_0_REG),
+		REG(1, true,  LCDC_DMA_FB_CEILING_ADDR_0_REG),
+		REG(1, true,  LCDC_DMA_FB_BASE_ADDR_1_REG),
+		REG(1, true,  LCDC_DMA_FB_CEILING_ADDR_1_REG),
+		/* new in revision 2: */
+		REG(2, false, LCDC_RAW_STAT_REG),
+		REG(2, false, LCDC_MASKED_STAT_REG),
+		REG(2, false, LCDC_INT_ENABLE_SET_REG),
+		REG(2, false, LCDC_INT_ENABLE_CLR_REG),
+		REG(2, false, LCDC_END_OF_INT_IND_REG),
+		REG(2, true,  LCDC_CLK_ENABLE_REG),
+		REG(2, true,  LCDC_INT_ENABLE_SET_REG),
+#undef REG
+};
+#endif
+
+#ifdef CONFIG_DEBUG_FS
+static int tilcdc_regs_show(struct seq_file *m, void *arg)
+{
+	struct drm_info_node *node = (struct drm_info_node *) m->private;
+	struct drm_device *dev = node->minor->dev;
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	unsigned i;
+
+	pm_runtime_get_sync(dev->dev);
+
+	seq_printf(m, "revision: %d\n", priv->rev);
+
+	for (i = 0; i < ARRAY_SIZE(registers); i++)
+		if (priv->rev >= registers[i].rev)
+			seq_printf(m, "%s:\t %08x\n", registers[i].name,
+					tilcdc_read(dev, registers[i].reg));
+
+	pm_runtime_put_sync(dev->dev);
+
+	return 0;
+}
+
+static int tilcdc_mm_show(struct seq_file *m, void *arg)
+{
+	struct drm_info_node *node = (struct drm_info_node *) m->private;
+	struct drm_device *dev = node->minor->dev;
+	return drm_mm_dump_table(m, dev->mm_private);
+}
+
+static struct drm_info_list tilcdc_debugfs_list[] = {
+		{ "regs", tilcdc_regs_show, 0 },
+		{ "mm",   tilcdc_mm_show,   0 },
+		{ "fb",   drm_fb_cma_debugfs_show, 0 },
+};
+
+static int tilcdc_debugfs_init(struct drm_minor *minor)
+{
+	struct drm_device *dev = minor->dev;
+	struct tilcdc_module *mod;
+	int ret;
+
+	ret = drm_debugfs_create_files(tilcdc_debugfs_list,
+			ARRAY_SIZE(tilcdc_debugfs_list),
+			minor->debugfs_root, minor);
+
+	list_for_each_entry(mod, &module_list, list)
+		if (mod->funcs->debugfs_init)
+			mod->funcs->debugfs_init(mod, minor);
+
+	if (ret) {
+		dev_err(dev->dev, "could not install tilcdc_debugfs_list\n");
+		return ret;
+	}
+
+	return ret;
+}
+
+static void tilcdc_debugfs_cleanup(struct drm_minor *minor)
+{
+	struct tilcdc_module *mod;
+	drm_debugfs_remove_files(tilcdc_debugfs_list,
+			ARRAY_SIZE(tilcdc_debugfs_list), minor);
+
+	list_for_each_entry(mod, &module_list, list)
+		if (mod->funcs->debugfs_cleanup)
+			mod->funcs->debugfs_cleanup(mod, minor);
+}
+#endif
+
+static const struct file_operations fops = {
+	.owner              = THIS_MODULE,
+	.open               = drm_open,
+	.release            = drm_release,
+	.unlocked_ioctl     = drm_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl       = drm_compat_ioctl,
+#endif
+	.poll               = drm_poll,
+	.read               = drm_read,
+	.fasync             = drm_fasync,
+	.llseek             = no_llseek,
+	.mmap               = drm_gem_cma_mmap,
+};
+
+static struct drm_driver tilcdc_driver = {
+	.driver_features    = DRIVER_HAVE_IRQ | DRIVER_GEM | DRIVER_MODESET,
+	.load               = tilcdc_load,
+	.unload             = tilcdc_unload,
+	.preclose           = tilcdc_preclose,
+	.lastclose          = tilcdc_lastclose,
+	.irq_handler        = tilcdc_irq,
+	.irq_preinstall     = tilcdc_irq_preinstall,
+	.irq_postinstall    = tilcdc_irq_postinstall,
+	.irq_uninstall      = tilcdc_irq_uninstall,
+	.get_vblank_counter = drm_vblank_count,
+	.enable_vblank      = tilcdc_enable_vblank,
+	.disable_vblank     = tilcdc_disable_vblank,
+	.gem_free_object    = drm_gem_cma_free_object,
+	.gem_vm_ops         = &drm_gem_cma_vm_ops,
+	.dumb_create        = drm_gem_cma_dumb_create,
+	.dumb_map_offset    = drm_gem_cma_dumb_map_offset,
+	.dumb_destroy       = drm_gem_cma_dumb_destroy,
+#ifdef CONFIG_DEBUG_FS
+	.debugfs_init       = tilcdc_debugfs_init,
+	.debugfs_cleanup    = tilcdc_debugfs_cleanup,
+#endif
+	.fops               = &fops,
+	.name               = "tilcdc",
+	.desc               = "TI LCD Controller DRM",
+	.date               = "20121205",
+	.major              = 1,
+	.minor              = 0,
+};
+
+/*
+ * Power management:
+ */
+
+#ifdef CONFIG_PM_SLEEP
+static int tilcdc_pm_suspend(struct device *dev)
+{
+	struct drm_device *ddev = dev_get_drvdata(dev);
+	struct tilcdc_drm_private *priv = ddev->dev_private;
+	unsigned i, n = 0;
+
+	drm_kms_helper_poll_disable(ddev);
+
+	/* Save register state: */
+	for (i = 0; i < ARRAY_SIZE(registers); i++)
+		if (registers[i].save && (priv->rev >= registers[i].rev))
+			priv->saved_register[n++] = tilcdc_read(ddev, registers[i].reg);
+
+	return 0;
+}
+
+static int tilcdc_pm_resume(struct device *dev)
+{
+	struct drm_device *ddev = dev_get_drvdata(dev);
+	struct tilcdc_drm_private *priv = ddev->dev_private;
+	unsigned i, n = 0;
+
+	/* Restore register state: */
+	for (i = 0; i < ARRAY_SIZE(registers); i++)
+		if (registers[i].save && (priv->rev >= registers[i].rev))
+			tilcdc_write(ddev, registers[i].reg, priv->saved_register[n++]);
+
+	drm_kms_helper_poll_enable(ddev);
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops tilcdc_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(tilcdc_pm_suspend, tilcdc_pm_resume)
+};
+
+/*
+ * Platform driver:
+ */
+
+static int tilcdc_pdev_probe(struct platform_device *pdev)
+{
+	/* bail out early if no DT data: */
+	if (!pdev->dev.of_node) {
+		dev_err(&pdev->dev, "device-tree data is missing\n");
+		return -ENXIO;
+	}
+
+	return drm_platform_init(&tilcdc_driver, pdev);
+}
+
+static int tilcdc_pdev_remove(struct platform_device *pdev)
+{
+	drm_platform_exit(&tilcdc_driver, pdev);
+
+	return 0;
+}
+
+static struct of_device_id tilcdc_of_match[] = {
+		{ .compatible = "ti,am33xx-tilcdc", },
+		{ },
+};
+MODULE_DEVICE_TABLE(of, tilcdc_of_match);
+
+static struct platform_driver tilcdc_platform_driver = {
+	.probe      = tilcdc_pdev_probe,
+	.remove     = tilcdc_pdev_remove,
+	.driver     = {
+		.owner  = THIS_MODULE,
+		.name   = "tilcdc",
+		.pm     = &tilcdc_pm_ops,
+		.of_match_table = tilcdc_of_match,
+	},
+};
+
+static int __init tilcdc_drm_init(void)
+{
+	DBG("init");
+	tilcdc_tfp410_init();
+	return platform_driver_register(&tilcdc_platform_driver);
+}
+
+static void __exit tilcdc_drm_fini(void)
+{
+	DBG("fini");
+	tilcdc_tfp410_fini();
+	platform_driver_unregister(&tilcdc_platform_driver);
+}
+
+module_init(tilcdc_drm_init);
+module_exit(tilcdc_drm_fini);
+
+MODULE_AUTHOR("Rob Clark <robdclark@gmail.com");
+MODULE_DESCRIPTION("TI LCD Controller DRM Driver");
+MODULE_LICENSE("GPL");

drivers/gpu/drm/tilcdc/tilcdc_drv.h

+/*
+ * Copyright (C) 2012 Texas Instruments
+ * Author: Rob Clark <robdclark@gmail.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/>.
+ */
+
+#ifndef __TILCDC_DRV_H__
+#define __TILCDC_DRV_H__
+
+#include <linux/clk.h>
+#include <linux/cpufreq.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/list.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+
+struct tilcdc_drm_private {
+	void __iomem *mmio;
+
+	struct clk *disp_clk;    /* display dpll */
+	struct clk *clk;         /* functional clock */
+	int rev;                 /* IP revision */
+
+	/* don't attempt resolutions w/ higher W * H * Hz: */
+	uint32_t max_bandwidth;
+
+	/* register contents saved across suspend/resume: */
+	u32 saved_register[12];
+
+#ifdef CONFIG_CPU_FREQ
+	struct notifier_block freq_transition;
+	unsigned int lcd_fck_rate;
+#endif
+
+	struct workqueue_struct *wq;
+
+	struct drm_fbdev_cma *fbdev;
+
+	struct drm_crtc *crtc;
+
+	unsigned int num_encoders;
+	struct drm_encoder *encoders[8];
+
+	unsigned int num_connectors;
+	struct drm_connector *connectors[8];
+};
+
+/* Sub-module for display.  Since we don't know at compile time what panels
+ * or display adapter(s) might be present (for ex, off chip dvi/tfp410,
+ * hdmi encoder, various lcd panels), the connector/encoder(s) are split into
+ * separate drivers.  If they are probed and found to be present, they
+ * register themselves with tilcdc_register_module().
+ */
+struct tilcdc_module;
+
+struct tilcdc_module_ops {
+	/* create appropriate encoders/connectors: */
+	int (*modeset_init)(struct tilcdc_module *mod, struct drm_device *dev);
+	void (*destroy)(struct tilcdc_module *mod);
+#ifdef CONFIG_DEBUG_FS
+	/* create debugfs nodes (can be NULL): */
+	int (*debugfs_init)(struct tilcdc_module *mod, struct drm_minor *minor);
+	/* cleanup debugfs nodes (can be NULL): */
+	void (*debugfs_cleanup)(struct tilcdc_module *mod, struct drm_minor *minor);
+#endif
+};
+
+struct tilcdc_module {
+	const char *name;
+	struct list_head list;
+	const struct tilcdc_module_ops *funcs;
+};
+
+void tilcdc_module_init(struct tilcdc_module *mod, const char *name,
+		const struct tilcdc_module_ops *funcs);
+void tilcdc_module_cleanup(struct tilcdc_module *mod);
+
+
+/* Panel config that needs to be set in the crtc, but is not coming from
+ * the mode timings.  The display module is expected to call
+ * tilcdc_crtc_set_panel_info() to set this during modeset.
+ */
+struct tilcdc_panel_info {
+
+	/* AC Bias Pin Frequency */
+	uint32_t ac_bias;
+
+	/* AC Bias Pin Transitions per Interrupt */
+	uint32_t ac_bias_intrpt;
+
+	/* DMA burst size */
+	uint32_t dma_burst_sz;
+
+	/* Bits per pixel */
+	uint32_t bpp;
+
+	/* FIFO DMA Request Delay */
+	uint32_t fdd;
+
+	/* TFT Alternative Signal Mapping (Only for active) */
+	bool tft_alt_mode;
+
+	/* Invert pixel clock */
+	bool invert_pxl_clk;
+
+	/* Horizontal and Vertical Sync Edge: 0=rising 1=falling */
+	uint32_t sync_edge;
+
+	/* Horizontal and Vertical Sync: Control: 0=ignore */
+	uint32_t sync_ctrl;
+
+	/* Raster Data Order Select: 1=Most-to-least 0=Least-to-most */
+	uint32_t raster_order;
+
+	/* DMA FIFO threshold */
+	uint32_t fifo_th;
+};
+
+#define DBG(fmt, ...) DRM_DEBUG(fmt"\n", ##__VA_ARGS__)
+
+struct drm_crtc *tilcdc_crtc_create(struct drm_device *dev);
+void tilcdc_crtc_cancel_page_flip(struct drm_crtc *crtc, struct drm_file *file);
+irqreturn_t tilcdc_crtc_irq(struct drm_crtc *crtc);
+void tilcdc_crtc_update_clk(struct drm_crtc *crtc);
+void tilcdc_crtc_set_panel_info(struct drm_crtc *crtc,
+		const struct tilcdc_panel_info *info);
+int tilcdc_crtc_mode_valid(struct drm_crtc *crtc, struct drm_display_mode *mode);
+int tilcdc_crtc_max_width(struct drm_crtc *crtc);
+
+#endif /* __TILCDC_DRV_H__ */

drivers/gpu/drm/tilcdc/tilcdc_regs.h

+/*
+ * Copyright (C) 2012 Texas Instruments
+ * Author: Rob Clark <robdclark@gmail.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/>.
+ */
+
+#ifndef __TILCDC_REGS_H__
+#define __TILCDC_REGS_H__
+
+/* LCDC register definitions, based on da8xx-fb */
+
+#include <linux/bitops.h>
+
+#include "tilcdc_drv.h"
+
+/* LCDC Status Register */
+#define LCDC_END_OF_FRAME1                       BIT(9)
+#define LCDC_END_OF_FRAME0                       BIT(8)
+#define LCDC_PL_LOAD_DONE                        BIT(6)
+#define LCDC_FIFO_UNDERFLOW                      BIT(5)
+#define LCDC_SYNC_LOST                           BIT(2)
+#define LCDC_FRAME_DONE                          BIT(0)
+
+/* LCDC DMA Control Register */
+#define LCDC_DMA_BURST_SIZE(x)                   ((x) << 4)
+#define LCDC_DMA_BURST_1                         0x0
+#define LCDC_DMA_BURST_2                         0x1
+#define LCDC_DMA_BURST_4                         0x2
+#define LCDC_DMA_BURST_8                         0x3
+#define LCDC_DMA_BURST_16                        0x4
+#define LCDC_V1_END_OF_FRAME_INT_ENA             BIT(2)
+#define LCDC_V2_END_OF_FRAME0_INT_ENA            BIT(8)
+#define LCDC_V2_END_OF_FRAME1_INT_ENA            BIT(9)
+#define LCDC_DUAL_FRAME_BUFFER_ENABLE            BIT(0)
+
+/* LCDC Control Register */
+#define LCDC_CLK_DIVISOR(x)                      ((x) << 8)
+#define LCDC_RASTER_MODE                         0x01
+
+/* LCDC Raster Control Register */
+#define LCDC_PALETTE_LOAD_MODE(x)                ((x) << 20)
+#define PALETTE_AND_DATA                         0x00
+#define PALETTE_ONLY                             0x01
+#define DATA_ONLY                                0x02
+
+#define LCDC_MONO_8BIT_MODE                      BIT(9)
+#define LCDC_RASTER_ORDER                        BIT(8)
+#define LCDC_TFT_MODE                            BIT(7)
+#define LCDC_V1_UNDERFLOW_INT_ENA                BIT(6)
+#define LCDC_V2_UNDERFLOW_INT_ENA                BIT(5)
+#define LCDC_V1_PL_INT_ENA                       BIT(4)
+#define LCDC_V2_PL_INT_ENA                       BIT(6)
+#define LCDC_MONOCHROME_MODE                     BIT(1)
+#define LCDC_RASTER_ENABLE                       BIT(0)
+#define LCDC_TFT_ALT_ENABLE                      BIT(23)
+#define LCDC_STN_565_ENABLE                      BIT(24)
+#define LCDC_V2_DMA_CLK_EN                       BIT(2)
+#define LCDC_V2_LIDD_CLK_EN                      BIT(1)
+#define LCDC_V2_CORE_CLK_EN                      BIT(0)
+#define LCDC_V2_LPP_B10                          26
+#define LCDC_V2_TFT_24BPP_MODE                   BIT(25)
+#define LCDC_V2_TFT_24BPP_UNPACK                 BIT(26)
+
+/* LCDC Raster Timing 2 Register */
+#define LCDC_AC_BIAS_TRANSITIONS_PER_INT(x)      ((x) << 16)
+#define LCDC_AC_BIAS_FREQUENCY(x)                ((x) << 8)
+#define LCDC_SYNC_CTRL                           BIT(25)
+#define LCDC_SYNC_EDGE                           BIT(24)
+#define LCDC_INVERT_PIXEL_CLOCK                  BIT(22)
+#define LCDC_INVERT_HSYNC                        BIT(21)
+#define LCDC_INVERT_VSYNC                        BIT(20)
+
+/* LCDC Block */
+#define LCDC_PID_REG                             0x0
+#define LCDC_CTRL_REG                            0x4
+#define LCDC_STAT_REG                            0x8
+#define LCDC_RASTER_CTRL_REG                     0x28
+#define LCDC_RASTER_TIMING_0_REG                 0x2c
+#define LCDC_RASTER_TIMING_1_REG                 0x30
+#define LCDC_RASTER_TIMING_2_REG                 0x34
+#define LCDC_DMA_CTRL_REG                        0x40
+#define LCDC_DMA_FB_BASE_ADDR_0_REG              0x44
+#define LCDC_DMA_FB_CEILING_ADDR_0_REG           0x48
+#define LCDC_DMA_FB_BASE_ADDR_1_REG              0x4c
+#define LCDC_DMA_FB_CEILING_ADDR_1_REG           0x50
+
+/* Interrupt Registers available only in Version 2 */
+#define LCDC_RAW_STAT_REG                        0x58
+#define LCDC_MASKED_STAT_REG                     0x5c
+#define LCDC_INT_ENABLE_SET_REG                  0x60
+#define LCDC_INT_ENABLE_CLR_REG                  0x64
+#define LCDC_END_OF_INT_IND_REG                  0x68
+
+/* Clock registers available only on Version 2 */
+#define LCDC_CLK_ENABLE_REG                      0x6c
+#define LCDC_CLK_RESET_REG                       0x70
+#define LCDC_CLK_MAIN_RESET                      BIT(3)
+
+
+/*
+ * Helpers:
+ */
+
+static inline void tilcdc_write(struct drm_device *dev, u32 reg, u32 data)
+{
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	iowrite32(data, priv->mmio + reg);
+}
+
+static inline u32 tilcdc_read(struct drm_device *dev, u32 reg)
+{
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	return ioread32(priv->mmio + reg);
+}
+
+static inline void tilcdc_set(struct drm_device *dev, u32 reg, u32 mask)
+{
+	tilcdc_write(dev, reg, tilcdc_read(dev, reg) | mask);
+}
+
+static inline void tilcdc_clear(struct drm_device *dev, u32 reg, u32 mask)
+{
+	tilcdc_write(dev, reg, tilcdc_read(dev, reg) & ~mask);
+}
+
+/* the register to read/clear irqstatus differs between v1 and v2 of the IP */
+static inline u32 tilcdc_irqstatus_reg(struct drm_device *dev)
+{
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	return (priv->rev == 2) ? LCDC_MASKED_STAT_REG : LCDC_STAT_REG;
+}
+
+static inline u32 tilcdc_read_irqstatus(struct drm_device *dev)
+{
+	return tilcdc_read(dev, tilcdc_irqstatus_reg(dev));
+}
+
+static inline void tilcdc_clear_irqstatus(struct drm_device *dev, u32 mask)
+{
+	tilcdc_write(dev, tilcdc_irqstatus_reg(dev), mask);
+}
+
+#endif /* __TILCDC_REGS_H__ */

drivers/gpu/drm/tilcdc/tilcdc_tfp410.c

+/*
+ * Copyright (C) 2012 Texas Instruments
+ * Author: Rob Clark <robdclark@gmail.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/i2c.h>
+#include <linux/of_i2c.h>
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/pinctrl/consumer.h>
+
+#include "tilcdc_drv.h"
+
+struct tfp410_module {
+	struct tilcdc_module base;
+	struct i2c_adapter *i2c;
+	int gpio;
+};
+#define to_tfp410_module(x) container_of(x, struct tfp410_module, base)
+
+
+static const struct tilcdc_panel_info dvi_info = {
+		.ac_bias                = 255,
+		.ac_bias_intrpt         = 0,
+		.dma_burst_sz           = 16,
+		.bpp                    = 16,
+		.fdd                    = 0x80,
+		.tft_alt_mode           = 0,
+		.sync_edge              = 0,
+		.sync_ctrl              = 1,
+		.raster_order           = 0,
+};
+
+/*
+ * Encoder:
+ */
+
+struct tfp410_encoder {
+	struct drm_encoder base;
+	struct tfp410_module *mod;
+	int dpms;
+};
+#define to_tfp410_encoder(x) container_of(x, struct tfp410_encoder, base)
+
+
+static void tfp410_encoder_destroy(struct drm_encoder *encoder)
+{
+	struct tfp410_encoder *tfp410_encoder = to_tfp410_encoder(encoder);
+	drm_encoder_cleanup(encoder);
+	kfree(tfp410_encoder);
+}
+
+static void tfp410_encoder_dpms(struct drm_encoder *encoder, int mode)
+{
+	struct tfp410_encoder *tfp410_encoder = to_tfp410_encoder(encoder);
+
+	if (tfp410_encoder->dpms == mode)
+		return;
+
+	if (mode == DRM_MODE_DPMS_ON) {
+		DBG("Power on");
+		gpio_direction_output(tfp410_encoder->mod->gpio, 1);
+	} else {
+		DBG("Power off");
+		gpio_direction_output(tfp410_encoder->mod->gpio, 0);
+	}
+
+	tfp410_encoder->dpms = mode;
+}
+
+static bool tfp410_encoder_mode_fixup(struct drm_encoder *encoder,
+		const struct drm_display_mode *mode,
+		struct drm_display_mode *adjusted_mode)
+{
+	/* nothing needed */
+	return true;
+}
+
+static void tfp410_encoder_prepare(struct drm_encoder *encoder)
+{
+	tfp410_encoder_dpms(encoder, DRM_MODE_DPMS_OFF);
+	tilcdc_crtc_set_panel_info(encoder->crtc, &dvi_info);
+}
+
+static void tfp410_encoder_commit(struct drm_encoder *encoder)
+{
+	tfp410_encoder_dpms(encoder, DRM_MODE_DPMS_ON);
+}
+
+static void tfp410_encoder_mode_set(struct drm_encoder *encoder,
+		struct drm_display_mode *mode,
+		struct drm_display_mode *adjusted_mode)
+{
+	/* nothing needed */
+}
+
+static const struct drm_encoder_funcs tfp410_encoder_funcs = {
+		.destroy        = tfp410_encoder_destroy,
+};
+
+static const struct drm_encoder_helper_funcs tfp410_encoder_helper_funcs = {
+		.dpms           = tfp410_encoder_dpms,
+		.mode_fixup     = tfp410_encoder_mode_fixup,
+		.prepare        = tfp410_encoder_prepare,
+		.commit         = tfp410_encoder_commit,
+		.mode_set       = tfp410_encoder_mode_set,
+};
+
+static struct drm_encoder *tfp410_encoder_create(struct drm_device *dev,
+		struct tfp410_module *mod)
+{
+	struct tfp410_encoder *tfp410_encoder;
+	struct drm_encoder *encoder;
+	int ret;
+
+	tfp410_encoder = kzalloc(sizeof(*tfp410_encoder), GFP_KERNEL);
+	if (!tfp410_encoder) {
+		dev_err(dev->dev, "allocation failed\n");
+		return NULL;
+	}
+
+	tfp410_encoder->dpms = DRM_MODE_DPMS_OFF;
+	tfp410_encoder->mod = mod;
+
+	encoder = &tfp410_encoder->base;
+	encoder->possible_crtcs = 1;
+
+	ret = drm_encoder_init(dev, encoder, &tfp410_encoder_funcs,
+			DRM_MODE_ENCODER_TMDS);
+	if (ret < 0)
+		goto fail;
+
+	drm_encoder_helper_add(encoder, &tfp410_encoder_helper_funcs);
+
+	return encoder;
+
+fail:
+	tfp410_encoder_destroy(encoder);
+	return NULL;
+}
+
+/*
+ * Connector:
+ */
+
+struct tfp410_connector {
+	struct drm_connector base;
+
+	struct drm_encoder *encoder;  /* our connected encoder */
+	struct tfp410_module *mod;
+};
+#define to_tfp410_connector(x) container_of(x, struct tfp410_connector, base)
+
+
+static void tfp410_connector_destroy(struct drm_connector *connector)
+{
+	struct tfp410_connector *tfp410_connector = to_tfp410_connector(connector);
+	drm_connector_cleanup(connector);
+	kfree(tfp410_connector);
+}
+
+static enum drm_connector_status tfp410_connector_detect(
+		struct drm_connector *connector,
+		bool force)
+{
+	struct tfp410_connector *tfp410_connector = to_tfp410_connector(connector);
+
+	if (drm_probe_ddc(tfp410_connector->mod->i2c))
+		return connector_status_connected;
+
+	return connector_status_unknown;
+}
+
+static int tfp410_connector_get_modes(struct drm_connector *connector)
+{
+	struct tfp410_connector *tfp410_connector = to_tfp410_connector(connector);
+	struct edid *edid;
+	int ret = 0;
+
+	edid = drm_get_edid(connector, tfp410_connector->mod->i2c);
+
+	drm_mode_connector_update_edid_property(connector, edid);
+
+	if (edid) {
+		ret = drm_add_edid_modes(connector, edid);
+		kfree(edid);
+	}
+
+	return ret;
+}
+
+static int tfp410_connector_mode_valid(struct drm_connector *connector,
+		  struct drm_display_mode *mode)
+{
+	struct tilcdc_drm_private *priv = connector->dev->dev_private;
+	/* our only constraints are what the crtc can generate: */
+	return tilcdc_crtc_mode_valid(priv->crtc, mode);
+}
+
+static struct drm_encoder *tfp410_connector_best_encoder(
+		struct drm_connector *connector)
+{
+	struct tfp410_connector *tfp410_connector = to_tfp410_connector(connector);
+	return tfp410_connector->encoder;
+}
+
+static const struct drm_connector_funcs tfp410_connector_funcs = {
+	.destroy            = tfp410_connector_destroy,
+	.dpms               = drm_helper_connector_dpms,
+	.detect             = tfp410_connector_detect,
+	.fill_modes         = drm_helper_probe_single_connector_modes,
+};
+
+static const struct drm_connector_helper_funcs tfp410_connector_helper_funcs = {
+	.get_modes          = tfp410_connector_get_modes,
+	.mode_valid         = tfp410_connector_mode_valid,
+	.best_encoder       = tfp410_connector_best_encoder,
+};
+
+static struct drm_connector *tfp410_connector_create(struct drm_device *dev,
+		struct tfp410_module *mod, struct drm_encoder *encoder)
+{
+	struct tfp410_connector *tfp410_connector;
+	struct drm_connector *connector;
+	int ret;
+
+	tfp410_connector = kzalloc(sizeof(*tfp410_connector), GFP_KERNEL);
+	if (!tfp410_connector) {
+		dev_err(dev->dev, "allocation failed\n");
+		return NULL;
+	}
+
+	tfp410_connector->encoder = encoder;
+	tfp410_connector->mod = mod;
+
+	connector = &tfp410_connector->base;
+
+	drm_connector_init(dev, connector, &tfp410_connector_funcs,
+			DRM_MODE_CONNECTOR_DVID);
+	drm_connector_helper_add(connector, &tfp410_connector_helper_funcs);
+
+	connector->polled = DRM_CONNECTOR_POLL_CONNECT |
+			DRM_CONNECTOR_POLL_DISCONNECT;
+
+	connector->interlace_allowed = 0;
+	connector->doublescan_allowed = 0;
+
+	ret = drm_mode_connector_attach_encoder(connector, encoder);
+	if (ret)
+		goto fail;
+
+	drm_sysfs_connector_add(connector);
+
+	return connector;
+
+fail:
+	tfp410_connector_destroy(connector);
+	return NULL;
+}
+
+/*
+ * Module:
+ */
+
+static int tfp410_modeset_init(struct tilcdc_module *mod, struct drm_device *dev)
+{
+	struct tfp410_module *tfp410_mod = to_tfp410_module(mod);
+	struct tilcdc_drm_private *priv = dev->dev_private;
+	struct drm_encoder *encoder;
+	struct drm_connector *connector;
+
+	encoder = tfp410_encoder_create(dev, tfp410_mod);
+	if (!encoder)
+		return -ENOMEM;
+
+	connector = tfp410_connector_create(dev, tfp410_mod, encoder);
+	if (!connector)
+		return -ENOMEM;
+
+	priv->encoders[priv->num_encoders++] = encoder;
+	priv->connectors[priv->num_connectors++] = connector;
+
+	return 0;
+}
+
+static void tfp410_destroy(struct tilcdc_module *mod)
+{
+	struct tfp410_module *tfp410_mod = to_tfp410_module(mod);
+
+	if (tfp410_mod->i2c)
+		i2c_put_adapter(tfp410_mod->i2c);
+
+	if (!IS_ERR_VALUE(tfp410_mod->gpio))
+		gpio_free(tfp410_mod->gpio);
+
+	tilcdc_module_cleanup(mod);
+	kfree(tfp410_mod);
+}
+
+static const struct tilcdc_module_ops tfp410_module_ops = {
+		.modeset_init = tfp410_modeset_init,
+		.destroy = tfp410_destroy,
+};
+
+/*
+ * Device:
+ */
+
+static struct of_device_id tfp410_of_match[];
+
+static int tfp410_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct device_node *i2c_node;
+	struct tfp410_module *tfp410_mod;
+	struct tilcdc_module *mod;
+	struct pinctrl *pinctrl;
+	uint32_t i2c_phandle;
+	int ret = -EINVAL;
+
+	/* bail out early if no DT data: */
+	if (!node) {
+		dev_err(&pdev->dev, "device-tree data is missing\n");
+		return -ENXIO;
+	}
+
+	tfp410_mod = kzalloc(sizeof(*tfp410_mod), GFP_KERNEL);
+	if (!tfp410_mod)
+		return -ENOMEM;
+
+	mod = &tfp410_mod->base;
+
+	tilcdc_module_init(mod, "tfp410", &tfp410_module_ops);
+
+	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
+	if (IS_ERR(pinctrl))
+		dev_warn(&pdev->dev, "pins are not configured\n");
+
+	if (of_property_read_u32(node, "i2c", &i2c_phandle)) {
+		dev_err(&pdev->dev, "could not get i2c bus phandle\n");
+		goto fail;
+	}
+
+	i2c_node = of_find_node_by_phandle(i2c_phandle);
+	if (!i2c_node) {
+		dev_err(&pdev->dev, "could not get i2c bus node\n");
+		goto fail;
+	}
+
+	tfp410_mod->i2c = of_find_i2c_adapter_by_node(i2c_node);
+	if (!tfp410_mod->i2c) {
+		dev_err(&pdev->dev, "could not get i2c\n");
+		goto fail;
+	}
+
+	of_node_put(i2c_node);
+
+	tfp410_mod->gpio = of_get_named_gpio_flags(node, "powerdn-gpio",
+			0, NULL);
+	if (IS_ERR_VALUE(tfp410_mod->gpio)) {
+		dev_warn(&pdev->dev, "No power down GPIO\n");
+	} else {
+		ret = gpio_request(tfp410_mod->gpio, "DVI_PDn");
+		if (ret) {
+			dev_err(&pdev->dev, "could not get DVI_PDn gpio\n");
+			goto fail;
+		}
+	}
+
+	return 0;
+
+fail:
+	tfp410_destroy(mod);
+	return ret;
+}
+
+static int tfp410_remove(struct platform_device *pdev)
+{
+	return 0;
+}
+
+static struct of_device_id tfp410_of_match[] = {
+		{ .compatible = "ti,tilcdc,tfp410", },
+		{ },
+};
+MODULE_DEVICE_TABLE(of, tfp410_of_match);
+
+struct platform_driver tfp410_driver = {
+	.probe = tfp410_probe,
+	.remove = tfp410_remove,
+	.driver = {
+		.owner = THIS_MODULE,
+		.name = "tfp410",
+		.of_match_table = tfp410_of_match,
+	},
+};
+
+int __init tilcdc_tfp410_init(void)
+{
+	return platform_driver_register(&tfp410_driver);
+}
+
+void __exit tilcdc_tfp410_fini(void)
+{
+	platform_driver_unregister(&tfp410_driver);
+}

drivers/gpu/drm/tilcdc/tilcdc_tfp410.h

+/*
+ * Copyright (C) 2012 Texas Instruments
+ * Author: Rob Clark <robdclark@gmail.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/>.
+ */
+
+#ifndef __TILCDC_TFP410_H__
+#define __TILCDC_TFP410_H__
+
+/* sub-module for tfp410 dvi adaptor */
+
+int tilcdc_tfp410_init(void);
+void tilcdc_tfp410_fini(void);
+
+#endif /* __TILCDC_TFP410_H__ */