// SPDX-License-Identifier: GPL-2.0
/*
 * TPD12S015 HDMI ESD protection & level shifter chip driver
 *
 * Copyright (C) 2019 Texas Instruments Incorporated
 *
 * Based on the omapdrm-specific encoder-opa362 driver
 *
 * Copyright (C) 2013 Texas Instruments Incorporated
 * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
 */

#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_graph.h>
#include <linux/platform_device.h>

#include <drm/drm_bridge.h>

struct tpd12s015_device {
        struct drm_bridge bridge;

        struct gpio_desc *ct_cp_hpd_gpio;
        struct gpio_desc *ls_oe_gpio;
        struct gpio_desc *hpd_gpio;
        int hpd_irq;
};

static inline struct tpd12s015_device *to_tpd12s015(struct drm_bridge *bridge)
{
        return container_of(bridge, struct tpd12s015_device, bridge);
}

static int tpd12s015_attach(struct drm_bridge *bridge,
                            struct drm_encoder *encoder,
                            enum drm_bridge_attach_flags flags)
{
        struct tpd12s015_device *tpd = to_tpd12s015(bridge);
        int ret;

        if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR))
                return -EINVAL;

        ret = drm_bridge_attach(encoder, tpd->bridge.next_bridge,
                                bridge, flags);
        if (ret < 0)
                return ret;

        gpiod_set_value_cansleep(tpd->ls_oe_gpio, 1);

        /* DC-DC converter needs at max 300us to get to 90% of 5V. */
        usleep_range(300, 1000);

        return 0;
}

static void tpd12s015_detach(struct drm_bridge *bridge)
{
        struct tpd12s015_device *tpd = to_tpd12s015(bridge);

        gpiod_set_value_cansleep(tpd->ls_oe_gpio, 0);
}

static enum drm_connector_status tpd12s015_detect(struct drm_bridge *bridge)
{
        struct tpd12s015_device *tpd = to_tpd12s015(bridge);

        if (gpiod_get_value_cansleep(tpd->hpd_gpio))
                return connector_status_connected;
        else
                return connector_status_disconnected;
}

static enum drm_connector_status
tpd12s015_bridge_detect(struct drm_bridge *bridge, struct drm_connector *connector)
{
        return tpd12s015_detect(bridge);
}

static void tpd12s015_hpd_enable(struct drm_bridge *bridge)
{
        struct tpd12s015_device *tpd = to_tpd12s015(bridge);

        gpiod_set_value_cansleep(tpd->ct_cp_hpd_gpio, 1);
}

static void tpd12s015_hpd_disable(struct drm_bridge *bridge)
{
        struct tpd12s015_device *tpd = to_tpd12s015(bridge);

        gpiod_set_value_cansleep(tpd->ct_cp_hpd_gpio, 0);
}

static const struct drm_bridge_funcs tpd12s015_bridge_funcs = {
        .attach                 = tpd12s015_attach,
        .detach                 = tpd12s015_detach,
        .detect                 = tpd12s015_bridge_detect,
        .hpd_enable             = tpd12s015_hpd_enable,
        .hpd_disable            = tpd12s015_hpd_disable,
};

static irqreturn_t tpd12s015_hpd_isr(int irq, void *data)
{
        struct tpd12s015_device *tpd = data;
        struct drm_bridge *bridge = &tpd->bridge;

        drm_bridge_hpd_notify(bridge, tpd12s015_detect(bridge));

        return IRQ_HANDLED;
}

static int tpd12s015_probe(struct platform_device *pdev)
{
        struct tpd12s015_device *tpd;
        struct device_node *node;
        struct gpio_desc *gpio;
        int ret;

        tpd = devm_drm_bridge_alloc(&pdev->dev, struct tpd12s015_device,
                                    bridge, &tpd12s015_bridge_funcs);
        if (IS_ERR(tpd))
                return PTR_ERR(tpd);

        platform_set_drvdata(pdev, tpd);

        tpd->bridge.of_node = pdev->dev.of_node;
        tpd->bridge.type = DRM_MODE_CONNECTOR_HDMIA;
        tpd->bridge.ops = DRM_BRIDGE_OP_DETECT;

        /* Get the next bridge, connected to port@1. */
        node = of_graph_get_remote_node(pdev->dev.of_node, 1, -1);
        if (!node)
                return -ENODEV;

        tpd->bridge.next_bridge = of_drm_find_and_get_bridge(node);
        of_node_put(node);

        if (!tpd->bridge.next_bridge)
                return -EPROBE_DEFER;

        /* Get the control and HPD GPIOs. */
        gpio = devm_gpiod_get_index_optional(&pdev->dev, NULL, 0,
                                             GPIOD_OUT_LOW);
        if (IS_ERR(gpio))
                return PTR_ERR(gpio);

        tpd->ct_cp_hpd_gpio = gpio;

        gpio = devm_gpiod_get_index_optional(&pdev->dev, NULL, 1,
                                             GPIOD_OUT_LOW);
        if (IS_ERR(gpio))
                return PTR_ERR(gpio);

        tpd->ls_oe_gpio = gpio;

        gpio = devm_gpiod_get_index(&pdev->dev, NULL, 2, GPIOD_IN);
        if (IS_ERR(gpio))
                return PTR_ERR(gpio);

        tpd->hpd_gpio = gpio;

        /* Register the IRQ if the HPD GPIO is IRQ-capable. */
        tpd->hpd_irq = gpiod_to_irq(tpd->hpd_gpio);
        if (tpd->hpd_irq >= 0) {
                ret = devm_request_threaded_irq(&pdev->dev, tpd->hpd_irq, NULL,
                                                tpd12s015_hpd_isr,
                                                IRQF_TRIGGER_RISING |
                                                IRQF_TRIGGER_FALLING |
                                                IRQF_ONESHOT,
                                                "tpd12s015 hpd", tpd);
                if (ret)
                        return ret;

                tpd->bridge.ops |= DRM_BRIDGE_OP_HPD;
        }

        /* Register the DRM bridge. */
        drm_bridge_add(&tpd->bridge);

        return 0;
}

static void tpd12s015_remove(struct platform_device *pdev)
{
        struct tpd12s015_device *tpd = platform_get_drvdata(pdev);

        drm_bridge_remove(&tpd->bridge);
}

static const struct of_device_id tpd12s015_of_match[] = {
        { .compatible = "ti,tpd12s015", },
        {},
};

MODULE_DEVICE_TABLE(of, tpd12s015_of_match);

static struct platform_driver tpd12s015_driver = {
        .probe  = tpd12s015_probe,
        .remove = tpd12s015_remove,
        .driver = {
                .name   = "tpd12s015",
                .of_match_table = tpd12s015_of_match,
        },
};

module_platform_driver(tpd12s015_driver);

MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen@ti.com>");
MODULE_DESCRIPTION("TPD12S015 HDMI level shifter and ESD protection driver");
MODULE_LICENSE("GPL");