/*
 * 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/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 "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) {
		dev_err(dev->dev, "allocation failed\n");
		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 enum drm_connector_status panel_connector_detect(
		struct drm_connector *connector,
		bool force)
{
	return connector_status_connected;
}

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,
	.dpms               = drm_atomic_helper_connector_dpms,
	.detect             = panel_connector_detect,
	.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) {
		dev_err(dev->dev, "allocation failed\n");
		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_mode_connector_attach_encoder(connector, encoder);
	if (ret)
		goto fail;

	drm_connector_register(connector);

	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) {
		pr_err("%s: allocation failed\n", __func__);
		of_node_put(info_np);
		return NULL;
	}

	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);
		of_node_put(info_np);
		return NULL;
	}
	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 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 = "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);
}