drivers/gpu/drm/tilcdc/tilcdc_tfp410.c - maze/linux - Git at Google

 /*
  * 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;
 	}

 	mod->preferred_bpp = dvi_info.bpp;

 	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", },
 		{ },
 };

 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);
 }
	/*
	* 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;
	}

	mod->preferred_bpp = dvi_info.bpp;

	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", },
	{ },
	};

	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);
	}