drivers/gpu/drm/tilcdc/tilcdc_panel.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2012 Texas Instruments
  * Author: Rob Clark <robdclark@gmail.com>
  */

 #include <linux/pinctrl/pinmux.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/backlight.h>
 #include <linux/gpio/consumer.h>
 #include <video/display_timing.h>
 #include <video/of_display_timing.h>
 #include <video/videomode.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_probe_helper.h>

 #include "tilcdc_drv.h"
 #include "tilcdc_panel.h"

 struct panel_module {
 	struct tilcdc_module base;
 	struct tilcdc_panel_info *info;
 	struct display_timings *timings;
 	struct backlight_device *backlight;
 	struct gpio_desc *enable_gpio;
 };
 #define to_panel_module(x) container_of(x, struct panel_module, base)


 /*
  * Encoder:
  */

 struct panel_encoder {
 	struct drm_encoder base;
 	struct panel_module *mod;
 };
 #define to_panel_encoder(x) container_of(x, struct panel_encoder, base)

 static void panel_encoder_dpms(struct drm_encoder *encoder, int mode)
 {
 	struct panel_encoder *panel_encoder = to_panel_encoder(encoder);
 	struct backlight_device *backlight = panel_encoder->mod->backlight;
 	struct gpio_desc *gpio = panel_encoder->mod->enable_gpio;

 	if (backlight) {
 		backlight->props.power = mode == DRM_MODE_DPMS_ON ?
 					 FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
 		backlight_update_status(backlight);
 	}

 	if (gpio)
 		gpiod_set_value_cansleep(gpio,
 					 mode == DRM_MODE_DPMS_ON ? 1 : 0);
 }

 static void panel_encoder_prepare(struct drm_encoder *encoder)
 {
 	panel_encoder_dpms(encoder, DRM_MODE_DPMS_OFF);
 }

 static void panel_encoder_commit(struct drm_encoder *encoder)
 {
 	panel_encoder_dpms(encoder, DRM_MODE_DPMS_ON);
 }

 static void panel_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 panel_encoder_funcs = {
 		.destroy        = drm_encoder_cleanup,
 };

 static const struct drm_encoder_helper_funcs panel_encoder_helper_funcs = {
 		.dpms           = panel_encoder_dpms,
 		.prepare        = panel_encoder_prepare,
 		.commit         = panel_encoder_commit,
 		.mode_set       = panel_encoder_mode_set,
 };

 static struct drm_encoder *panel_encoder_create(struct drm_device *dev,
 		struct panel_module *mod)
 {
 	struct panel_encoder *panel_encoder;
 	struct drm_encoder *encoder;
 	int ret;

 	panel_encoder = devm_kzalloc(dev->dev, sizeof(*panel_encoder),
 				     GFP_KERNEL);
 	if (!panel_encoder)
 		return NULL;

 	panel_encoder->mod = mod;

 	encoder = &panel_encoder->base;
 	encoder->possible_crtcs = 1;

 	ret = drm_encoder_init(dev, encoder, &panel_encoder_funcs,
 			DRM_MODE_ENCODER_LVDS, NULL);
 	if (ret < 0)
 		goto fail;

 	drm_encoder_helper_add(encoder, &panel_encoder_helper_funcs);

 	return encoder;

 fail:
 	drm_encoder_cleanup(encoder);
 	return NULL;
 }

 /*
  * Connector:
  */

 struct panel_connector {
 	struct drm_connector base;

 	struct drm_encoder *encoder;  /* our connected encoder */
 	struct panel_module *mod;
 };
 #define to_panel_connector(x) container_of(x, struct panel_connector, base)


 static void panel_connector_destroy(struct drm_connector *connector)
 {
 	drm_connector_unregister(connector);
 	drm_connector_cleanup(connector);
 }

 static int panel_connector_get_modes(struct drm_connector *connector)
 {
 	struct drm_device *dev = connector->dev;
 	struct panel_connector *panel_connector = to_panel_connector(connector);
 	struct display_timings *timings = panel_connector->mod->timings;
 	int i;

 	for (i = 0; i < timings->num_timings; i++) {
 		struct drm_display_mode *mode = drm_mode_create(dev);
 		struct videomode vm;

 		if (videomode_from_timings(timings, &vm, i))
 			break;

 		drm_display_mode_from_videomode(&vm, mode);

 		mode->type = DRM_MODE_TYPE_DRIVER;

 		if (timings->native_mode == i)
 			mode->type |= DRM_MODE_TYPE_PREFERRED;

 		drm_mode_set_name(mode);
 		drm_mode_probed_add(connector, mode);
 	}

 	return i;
 }

 static int panel_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 *panel_connector_best_encoder(
 		struct drm_connector *connector)
 {
 	struct panel_connector *panel_connector = to_panel_connector(connector);
 	return panel_connector->encoder;
 }

 static const struct drm_connector_funcs panel_connector_funcs = {
 	.destroy            = panel_connector_destroy,
 	.fill_modes         = drm_helper_probe_single_connector_modes,
 	.reset              = drm_atomic_helper_connector_reset,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
 };

 static const struct drm_connector_helper_funcs panel_connector_helper_funcs = {
 	.get_modes          = panel_connector_get_modes,
 	.mode_valid         = panel_connector_mode_valid,
 	.best_encoder       = panel_connector_best_encoder,
 };

 static struct drm_connector *panel_connector_create(struct drm_device *dev,
 		struct panel_module *mod, struct drm_encoder *encoder)
 {
 	struct panel_connector *panel_connector;
 	struct drm_connector *connector;
 	int ret;

 	panel_connector = devm_kzalloc(dev->dev, sizeof(*panel_connector),
 				       GFP_KERNEL);
 	if (!panel_connector)
 		return NULL;

 	panel_connector->encoder = encoder;
 	panel_connector->mod = mod;

 	connector = &panel_connector->base;

 	drm_connector_init(dev, connector, &panel_connector_funcs,
 			DRM_MODE_CONNECTOR_LVDS);
 	drm_connector_helper_add(connector, &panel_connector_helper_funcs);

 	connector->interlace_allowed = 0;
 	connector->doublescan_allowed = 0;

 	ret = drm_connector_attach_encoder(connector, encoder);
 	if (ret)
 		goto fail;

 	return connector;

 fail:
 	panel_connector_destroy(connector);
 	return NULL;
 }

 /*
  * Module:
  */

 static int panel_modeset_init(struct tilcdc_module *mod, struct drm_device *dev)
 {
 	struct panel_module *panel_mod = to_panel_module(mod);
 	struct tilcdc_drm_private *priv = dev->dev_private;
 	struct drm_encoder *encoder;
 	struct drm_connector *connector;

 	encoder = panel_encoder_create(dev, panel_mod);
 	if (!encoder)
 		return -ENOMEM;

 	connector = panel_connector_create(dev, panel_mod, encoder);
 	if (!connector)
 		return -ENOMEM;

 	priv->encoders[priv->num_encoders++] = encoder;
 	priv->connectors[priv->num_connectors++] = connector;

 	tilcdc_crtc_set_panel_info(priv->crtc,
 				   to_panel_encoder(encoder)->mod->info);

 	return 0;
 }

 static const struct tilcdc_module_ops panel_module_ops = {
 		.modeset_init = panel_modeset_init,
 };

 /*
  * Device:
  */

 /* maybe move this somewhere common if it is needed by other outputs? */
 static struct tilcdc_panel_info *of_get_panel_info(struct device_node *np)
 {
 	struct device_node *info_np;
 	struct tilcdc_panel_info *info;
 	int ret = 0;

 	if (!np) {
 		pr_err("%s: no devicenode given\n", __func__);
 		return NULL;
 	}

 	info_np = of_get_child_by_name(np, "panel-info");
 	if (!info_np) {
 		pr_err("%s: could not find panel-info node\n", __func__);
 		return NULL;
 	}

 	info = kzalloc(sizeof(*info), GFP_KERNEL);
 	if (!info)
 		goto put_node;

 	ret |= of_property_read_u32(info_np, "ac-bias", &info->ac_bias);
 	ret |= of_property_read_u32(info_np, "ac-bias-intrpt", &info->ac_bias_intrpt);
 	ret |= of_property_read_u32(info_np, "dma-burst-sz", &info->dma_burst_sz);
 	ret |= of_property_read_u32(info_np, "bpp", &info->bpp);
 	ret |= of_property_read_u32(info_np, "fdd", &info->fdd);
 	ret |= of_property_read_u32(info_np, "sync-edge", &info->sync_edge);
 	ret |= of_property_read_u32(info_np, "sync-ctrl", &info->sync_ctrl);
 	ret |= of_property_read_u32(info_np, "raster-order", &info->raster_order);
 	ret |= of_property_read_u32(info_np, "fifo-th", &info->fifo_th);

 	/* optional: */
 	info->tft_alt_mode      = of_property_read_bool(info_np, "tft-alt-mode");
 	info->invert_pxl_clk    = of_property_read_bool(info_np, "invert-pxl-clk");

 	if (ret) {
 		pr_err("%s: error reading panel-info properties\n", __func__);
 		kfree(info);
 		info = NULL;
 	}

 put_node:
 	of_node_put(info_np);
 	return info;
 }

 static int panel_probe(struct platform_device *pdev)
 {
 	struct device_node *bl_node, *node = pdev->dev.of_node;
 	struct panel_module *panel_mod;
 	struct tilcdc_module *mod;
 	struct pinctrl *pinctrl;
 	int ret;

 	/* bail out early if no DT data: */
 	if (!node) {
 		dev_err(&pdev->dev, "device-tree data is missing\n");
 		return -ENXIO;
 	}

 	panel_mod = devm_kzalloc(&pdev->dev, sizeof(*panel_mod), GFP_KERNEL);
 	if (!panel_mod)
 		return -ENOMEM;

 	bl_node = of_parse_phandle(node, "backlight", 0);
 	if (bl_node) {
 		panel_mod->backlight = of_find_backlight_by_node(bl_node);
 		of_node_put(bl_node);

 		if (!panel_mod->backlight)
 			return -EPROBE_DEFER;

 		dev_info(&pdev->dev, "found backlight\n");
 	}

 	panel_mod->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
 							 GPIOD_OUT_LOW);
 	if (IS_ERR(panel_mod->enable_gpio)) {
 		ret = PTR_ERR(panel_mod->enable_gpio);
 		dev_err(&pdev->dev, "failed to request enable GPIO\n");
 		goto fail_backlight;
 	}

 	if (panel_mod->enable_gpio)
 		dev_info(&pdev->dev, "found enable GPIO\n");

 	mod = &panel_mod->base;
 	pdev->dev.platform_data = mod;

 	tilcdc_module_init(mod, "panel", &panel_module_ops);

 	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
 	if (IS_ERR(pinctrl))
 		dev_warn(&pdev->dev, "pins are not configured\n");

 	panel_mod->timings = of_get_display_timings(node);
 	if (!panel_mod->timings) {
 		dev_err(&pdev->dev, "could not get panel timings\n");
 		ret = -EINVAL;
 		goto fail_free;
 	}

 	panel_mod->info = of_get_panel_info(node);
 	if (!panel_mod->info) {
 		dev_err(&pdev->dev, "could not get panel info\n");
 		ret = -EINVAL;
 		goto fail_timings;
 	}

 	return 0;

 fail_timings:
 	display_timings_release(panel_mod->timings);

 fail_free:
 	tilcdc_module_cleanup(mod);

 fail_backlight:
 	if (panel_mod->backlight)
 		put_device(&panel_mod->backlight->dev);
 	return ret;
 }

 static int panel_remove(struct platform_device *pdev)
 {
 	struct tilcdc_module *mod = dev_get_platdata(&pdev->dev);
 	struct panel_module *panel_mod = to_panel_module(mod);
 	struct backlight_device *backlight = panel_mod->backlight;

 	if (backlight)
 		put_device(&backlight->dev);

 	display_timings_release(panel_mod->timings);

 	tilcdc_module_cleanup(mod);
 	kfree(panel_mod->info);

 	return 0;
 }

 static const struct of_device_id panel_of_match[] = {
 		{ .compatible = "ti,tilcdc,panel", },
 		{ },
 };

 struct platform_driver panel_driver = {
 	.probe = panel_probe,
 	.remove = panel_remove,
 	.driver = {
 		.owner = THIS_MODULE,
 		.name = "tilcdc-panel",
 		.of_match_table = panel_of_match,
 	},
 };

 int __init tilcdc_panel_init(void)
 {
 	return platform_driver_register(&panel_driver);
 }

 void __exit tilcdc_panel_fini(void)
 {
 	platform_driver_unregister(&panel_driver);
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright (C) 2012 Texas Instruments
	* Author: Rob Clark <robdclark@gmail.com>
	*/

	#include <linux/pinctrl/pinmux.h>
	#include <linux/pinctrl/consumer.h>
	#include <linux/backlight.h>
	#include <linux/gpio/consumer.h>
	#include <video/display_timing.h>
	#include <video/of_display_timing.h>
	#include <video/videomode.h>
	#include <drm/drm_atomic_helper.h>
	#include <drm/drm_probe_helper.h>

	#include "tilcdc_drv.h"
	#include "tilcdc_panel.h"

	struct panel_module {
	struct tilcdc_module base;
	struct tilcdc_panel_info *info;
	struct display_timings *timings;
	struct backlight_device *backlight;
	struct gpio_desc *enable_gpio;
	};
	#define to_panel_module(x) container_of(x, struct panel_module, base)


	/*
	* Encoder:
	*/

	struct panel_encoder {
	struct drm_encoder base;
	struct panel_module *mod;
	};
	#define to_panel_encoder(x) container_of(x, struct panel_encoder, base)

	static void panel_encoder_dpms(struct drm_encoder *encoder, int mode)
	{
	struct panel_encoder *panel_encoder = to_panel_encoder(encoder);
	struct backlight_device *backlight = panel_encoder->mod->backlight;
	struct gpio_desc *gpio = panel_encoder->mod->enable_gpio;

	if (backlight) {
	backlight->props.power = mode == DRM_MODE_DPMS_ON ?
	FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
	backlight_update_status(backlight);
	}

	if (gpio)
	gpiod_set_value_cansleep(gpio,
	mode == DRM_MODE_DPMS_ON ? 1 : 0);
	}

	static void panel_encoder_prepare(struct drm_encoder *encoder)
	{
	panel_encoder_dpms(encoder, DRM_MODE_DPMS_OFF);
	}

	static void panel_encoder_commit(struct drm_encoder *encoder)
	{
	panel_encoder_dpms(encoder, DRM_MODE_DPMS_ON);
	}

	static void panel_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 panel_encoder_funcs = {
	.destroy = drm_encoder_cleanup,
	};

	static const struct drm_encoder_helper_funcs panel_encoder_helper_funcs = {
	.dpms = panel_encoder_dpms,
	.prepare = panel_encoder_prepare,
	.commit = panel_encoder_commit,
	.mode_set = panel_encoder_mode_set,
	};

	static struct drm_encoder panel_encoder_create(struct drm_device dev,
	struct panel_module *mod)
	{
	struct panel_encoder *panel_encoder;
	struct drm_encoder *encoder;
	int ret;

	panel_encoder = devm_kzalloc(dev->dev, sizeof(*panel_encoder),
	GFP_KERNEL);
	if (!panel_encoder)
	return NULL;

	panel_encoder->mod = mod;

	encoder = &panel_encoder->base;
	encoder->possible_crtcs = 1;

	ret = drm_encoder_init(dev, encoder, &panel_encoder_funcs,
	DRM_MODE_ENCODER_LVDS, NULL);
	if (ret < 0)
	goto fail;

	drm_encoder_helper_add(encoder, &panel_encoder_helper_funcs);

	return encoder;

	fail:
	drm_encoder_cleanup(encoder);
	return NULL;
	}

	/*
	* Connector:
	*/

	struct panel_connector {
	struct drm_connector base;

	struct drm_encoder encoder; / our connected encoder */
	struct panel_module *mod;
	};
	#define to_panel_connector(x) container_of(x, struct panel_connector, base)


	static void panel_connector_destroy(struct drm_connector *connector)
	{
	drm_connector_unregister(connector);
	drm_connector_cleanup(connector);
	}

	static int panel_connector_get_modes(struct drm_connector *connector)
	{
	struct drm_device *dev = connector->dev;
	struct panel_connector *panel_connector = to_panel_connector(connector);
	struct display_timings *timings = panel_connector->mod->timings;
	int i;

	for (i = 0; i < timings->num_timings; i++) {
	struct drm_display_mode *mode = drm_mode_create(dev);
	struct videomode vm;

	if (videomode_from_timings(timings, &vm, i))
	break;

	drm_display_mode_from_videomode(&vm, mode);

	mode->type = DRM_MODE_TYPE_DRIVER;

	if (timings->native_mode == i)
	mode->type \|= DRM_MODE_TYPE_PREFERRED;

	drm_mode_set_name(mode);
	drm_mode_probed_add(connector, mode);
	}

	return i;
	}

	static int panel_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 *panel_connector_best_encoder(
	struct drm_connector *connector)
	{
	struct panel_connector *panel_connector = to_panel_connector(connector);
	return panel_connector->encoder;
	}

	static const struct drm_connector_funcs panel_connector_funcs = {
	.destroy = panel_connector_destroy,
	.fill_modes = drm_helper_probe_single_connector_modes,
	.reset = drm_atomic_helper_connector_reset,
	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
	};

	static const struct drm_connector_helper_funcs panel_connector_helper_funcs = {
	.get_modes = panel_connector_get_modes,
	.mode_valid = panel_connector_mode_valid,
	.best_encoder = panel_connector_best_encoder,
	};

	static struct drm_connector panel_connector_create(struct drm_device dev,
	struct panel_module mod, struct drm_encoder encoder)
	{
	struct panel_connector *panel_connector;
	struct drm_connector *connector;
	int ret;

	panel_connector = devm_kzalloc(dev->dev, sizeof(*panel_connector),
	GFP_KERNEL);
	if (!panel_connector)
	return NULL;

	panel_connector->encoder = encoder;
	panel_connector->mod = mod;

	connector = &panel_connector->base;

	drm_connector_init(dev, connector, &panel_connector_funcs,
	DRM_MODE_CONNECTOR_LVDS);
	drm_connector_helper_add(connector, &panel_connector_helper_funcs);

	connector->interlace_allowed = 0;
	connector->doublescan_allowed = 0;

	ret = drm_connector_attach_encoder(connector, encoder);
	if (ret)
	goto fail;

	return connector;

	fail:
	panel_connector_destroy(connector);
	return NULL;
	}

	/*
	* Module:
	*/

	static int panel_modeset_init(struct tilcdc_module mod, struct drm_device dev)
	{
	struct panel_module *panel_mod = to_panel_module(mod);
	struct tilcdc_drm_private *priv = dev->dev_private;
	struct drm_encoder *encoder;
	struct drm_connector *connector;

	encoder = panel_encoder_create(dev, panel_mod);
	if (!encoder)
	return -ENOMEM;

	connector = panel_connector_create(dev, panel_mod, encoder);
	if (!connector)
	return -ENOMEM;

	priv->encoders[priv->num_encoders++] = encoder;
	priv->connectors[priv->num_connectors++] = connector;

	tilcdc_crtc_set_panel_info(priv->crtc,
	to_panel_encoder(encoder)->mod->info);

	return 0;
	}

	static const struct tilcdc_module_ops panel_module_ops = {
	.modeset_init = panel_modeset_init,
	};

	/*
	* Device:
	*/

	/* maybe move this somewhere common if it is needed by other outputs? */
	static struct tilcdc_panel_info of_get_panel_info(struct device_node np)
	{
	struct device_node *info_np;
	struct tilcdc_panel_info *info;
	int ret = 0;

	if (!np) {
	pr_err("%s: no devicenode given\n", __func__);
	return NULL;
	}

	info_np = of_get_child_by_name(np, "panel-info");
	if (!info_np) {
	pr_err("%s: could not find panel-info node\n", __func__);
	return NULL;
	}

	info = kzalloc(sizeof(*info), GFP_KERNEL);
	if (!info)
	goto put_node;

	ret \|= of_property_read_u32(info_np, "ac-bias", &info->ac_bias);
	ret \|= of_property_read_u32(info_np, "ac-bias-intrpt", &info->ac_bias_intrpt);
	ret \|= of_property_read_u32(info_np, "dma-burst-sz", &info->dma_burst_sz);
	ret \|= of_property_read_u32(info_np, "bpp", &info->bpp);
	ret \|= of_property_read_u32(info_np, "fdd", &info->fdd);
	ret \|= of_property_read_u32(info_np, "sync-edge", &info->sync_edge);
	ret \|= of_property_read_u32(info_np, "sync-ctrl", &info->sync_ctrl);
	ret \|= of_property_read_u32(info_np, "raster-order", &info->raster_order);
	ret \|= of_property_read_u32(info_np, "fifo-th", &info->fifo_th);

	/* optional: */
	info->tft_alt_mode = of_property_read_bool(info_np, "tft-alt-mode");
	info->invert_pxl_clk = of_property_read_bool(info_np, "invert-pxl-clk");

	if (ret) {
	pr_err("%s: error reading panel-info properties\n", __func__);
	kfree(info);
	info = NULL;
	}

	put_node:
	of_node_put(info_np);
	return info;
	}

	static int panel_probe(struct platform_device *pdev)
	{
	struct device_node bl_node, node = pdev->dev.of_node;
	struct panel_module *panel_mod;
	struct tilcdc_module *mod;
	struct pinctrl *pinctrl;
	int ret;

	/* bail out early if no DT data: */
	if (!node) {
	dev_err(&pdev->dev, "device-tree data is missing\n");
	return -ENXIO;
	}

	panel_mod = devm_kzalloc(&pdev->dev, sizeof(*panel_mod), GFP_KERNEL);
	if (!panel_mod)
	return -ENOMEM;

	bl_node = of_parse_phandle(node, "backlight", 0);
	if (bl_node) {
	panel_mod->backlight = of_find_backlight_by_node(bl_node);
	of_node_put(bl_node);

	if (!panel_mod->backlight)
	return -EPROBE_DEFER;

	dev_info(&pdev->dev, "found backlight\n");
	}

	panel_mod->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
	GPIOD_OUT_LOW);
	if (IS_ERR(panel_mod->enable_gpio)) {
	ret = PTR_ERR(panel_mod->enable_gpio);
	dev_err(&pdev->dev, "failed to request enable GPIO\n");
	goto fail_backlight;
	}

	if (panel_mod->enable_gpio)
	dev_info(&pdev->dev, "found enable GPIO\n");

	mod = &panel_mod->base;
	pdev->dev.platform_data = mod;

	tilcdc_module_init(mod, "panel", &panel_module_ops);

	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
	if (IS_ERR(pinctrl))
	dev_warn(&pdev->dev, "pins are not configured\n");

	panel_mod->timings = of_get_display_timings(node);
	if (!panel_mod->timings) {
	dev_err(&pdev->dev, "could not get panel timings\n");
	ret = -EINVAL;
	goto fail_free;
	}

	panel_mod->info = of_get_panel_info(node);
	if (!panel_mod->info) {
	dev_err(&pdev->dev, "could not get panel info\n");
	ret = -EINVAL;
	goto fail_timings;
	}

	return 0;

	fail_timings:
	display_timings_release(panel_mod->timings);

	fail_free:
	tilcdc_module_cleanup(mod);

	fail_backlight:
	if (panel_mod->backlight)
	put_device(&panel_mod->backlight->dev);
	return ret;
	}

	static int panel_remove(struct platform_device *pdev)
	{
	struct tilcdc_module *mod = dev_get_platdata(&pdev->dev);
	struct panel_module *panel_mod = to_panel_module(mod);
	struct backlight_device *backlight = panel_mod->backlight;

	if (backlight)
	put_device(&backlight->dev);

	display_timings_release(panel_mod->timings);

	tilcdc_module_cleanup(mod);
	kfree(panel_mod->info);

	return 0;
	}

	static const struct of_device_id panel_of_match[] = {
	{ .compatible = "ti,tilcdc,panel", },
	{ },
	};

	struct platform_driver panel_driver = {
	.probe = panel_probe,
	.remove = panel_remove,
	.driver = {
	.owner = THIS_MODULE,
	.name = "tilcdc-panel",
	.of_match_table = panel_of_match,
	},
	};

	int __init tilcdc_panel_init(void)
	{
	return platform_driver_register(&panel_driver);
	}

	void __exit tilcdc_panel_fini(void)
	{
	platform_driver_unregister(&panel_driver);
	}