/*
 *  Driver for Goodix Touchscreens
 *
 *  Copyright (c) 2014 Red Hat Inc.
 *  Copyright (c) 2015 K. Merker <merker@debian.org>
 *
 *  This code is based on gt9xx.c authored by andrew@goodix.com:
 *
 *  2010 - 2012 Goodix Technology.
 */

/*
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; version 2 of the License.
 */

#include <linux/kernel.h>
#include <linux/dmi.h>
#include <linux/firmware.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/input/mt.h>
#include <linux/input/touchscreen.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/of.h>
#include <asm/unaligned.h>

struct goodix_ts_data;

struct goodix_chip_data {
        u16 config_addr;
        int config_len;
        int (*check_config)(struct goodix_ts_data *, const struct firmware *);
};

struct goodix_ts_data {
        struct i2c_client *client;
        struct input_dev *input_dev;
        const struct goodix_chip_data *chip;
        struct touchscreen_properties prop;
        unsigned int max_touch_num;
        unsigned int int_trigger_type;
        struct gpio_desc *gpiod_int;
        struct gpio_desc *gpiod_rst;
        u16 id;
        u16 version;
        const char *cfg_name;
        struct completion firmware_loading_complete;
        unsigned long irq_flags;
};

#define GOODIX_GPIO_INT_NAME            "irq"
#define GOODIX_GPIO_RST_NAME            "reset"

#define GOODIX_MAX_HEIGHT               4096
#define GOODIX_MAX_WIDTH                4096
#define GOODIX_INT_TRIGGER              1
#define GOODIX_CONTACT_SIZE             8
#define GOODIX_MAX_CONTACTS             10

#define GOODIX_CONFIG_MAX_LENGTH        240
#define GOODIX_CONFIG_911_LENGTH        186
#define GOODIX_CONFIG_967_LENGTH        228

/* Register defines */
#define GOODIX_REG_COMMAND              0x8040
#define GOODIX_CMD_SCREEN_OFF           0x05

#define GOODIX_READ_COOR_ADDR           0x814E
#define GOODIX_GT1X_REG_CONFIG_DATA     0x8050
#define GOODIX_GT9X_REG_CONFIG_DATA     0x8047
#define GOODIX_REG_ID                   0x8140

#define GOODIX_BUFFER_STATUS_READY      BIT(7)
#define GOODIX_BUFFER_STATUS_TIMEOUT    20

#define RESOLUTION_LOC          1
#define MAX_CONTACTS_LOC        5
#define TRIGGER_LOC             6

static int goodix_check_cfg_8(struct goodix_ts_data *ts,
                        const struct firmware *cfg);
static int goodix_check_cfg_16(struct goodix_ts_data *ts,
                        const struct firmware *cfg);

static const struct goodix_chip_data gt1x_chip_data = {
        .config_addr            = GOODIX_GT1X_REG_CONFIG_DATA,
        .config_len             = GOODIX_CONFIG_MAX_LENGTH,
        .check_config           = goodix_check_cfg_16,
};

static const struct goodix_chip_data gt911_chip_data = {
        .config_addr            = GOODIX_GT9X_REG_CONFIG_DATA,
        .config_len             = GOODIX_CONFIG_911_LENGTH,
        .check_config           = goodix_check_cfg_8,
};

static const struct goodix_chip_data gt967_chip_data = {
        .config_addr            = GOODIX_GT9X_REG_CONFIG_DATA,
        .config_len             = GOODIX_CONFIG_967_LENGTH,
        .check_config           = goodix_check_cfg_8,
};

static const struct goodix_chip_data gt9x_chip_data = {
        .config_addr            = GOODIX_GT9X_REG_CONFIG_DATA,
        .config_len             = GOODIX_CONFIG_MAX_LENGTH,
        .check_config           = goodix_check_cfg_8,
};

static const unsigned long goodix_irq_flags[] = {
        IRQ_TYPE_EDGE_RISING,
        IRQ_TYPE_EDGE_FALLING,
        IRQ_TYPE_LEVEL_LOW,
        IRQ_TYPE_LEVEL_HIGH,
};

/*
 * Those tablets have their coordinates origin at the bottom right
 * of the tablet, as if rotated 180 degrees
 */
static const struct dmi_system_id rotated_screen[] = {
#if defined(CONFIG_DMI) && defined(CONFIG_X86)
        {
                .ident = "WinBook TW100",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "WinBook"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "TW100")
                }
        },
        {
                .ident = "WinBook TW700",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "WinBook"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "TW700")
                },
        },
#endif
        {}
};

/**
 * goodix_i2c_read - read data from a register of the i2c slave device.
 *
 * @client: i2c device.
 * @reg: the register to read from.
 * @buf: raw write data buffer.
 * @len: length of the buffer to write
 */
static int goodix_i2c_read(struct i2c_client *client,
                           u16 reg, u8 *buf, int len)
{
        struct i2c_msg msgs[2];
        __be16 wbuf = cpu_to_be16(reg);
        int ret;

        msgs[0].flags = 0;
        msgs[0].addr  = client->addr;
        msgs[0].len   = 2;
        msgs[0].buf   = (u8 *)&wbuf;

        msgs[1].flags = I2C_M_RD;
        msgs[1].addr  = client->addr;
        msgs[1].len   = len;
        msgs[1].buf   = buf;

        ret = i2c_transfer(client->adapter, msgs, 2);
        return ret < 0 ? ret : (ret != ARRAY_SIZE(msgs) ? -EIO : 0);
}

/**
 * goodix_i2c_write - write data to a register of the i2c slave device.
 *
 * @client: i2c device.
 * @reg: the register to write to.
 * @buf: raw data buffer to write.
 * @len: length of the buffer to write
 */
static int goodix_i2c_write(struct i2c_client *client, u16 reg, const u8 *buf,
                            unsigned len)
{
        u8 *addr_buf;
        struct i2c_msg msg;
        int ret;

        addr_buf = kmalloc(len + 2, GFP_KERNEL);
        if (!addr_buf)
                return -ENOMEM;

        addr_buf[0] = reg >> 8;
        addr_buf[1] = reg & 0xFF;
        memcpy(&addr_buf[2], buf, len);

        msg.flags = 0;
        msg.addr = client->addr;
        msg.buf = addr_buf;
        msg.len = len + 2;

        ret = i2c_transfer(client->adapter, &msg, 1);
        kfree(addr_buf);
        return ret < 0 ? ret : (ret != 1 ? -EIO : 0);
}

static int goodix_i2c_write_u8(struct i2c_client *client, u16 reg, u8 value)
{
        return goodix_i2c_write(client, reg, &value, sizeof(value));
}

static const struct goodix_chip_data *goodix_get_chip_data(u16 id)
{
        switch (id) {
        case 1151:
                return &gt1x_chip_data;

        case 911:
        case 9271:
        case 9110:
        case 927:
        case 928:
                return &gt911_chip_data;

        case 912:
        case 967:
                return &gt967_chip_data;

        default:
                return &gt9x_chip_data;
        }
}

static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
{
        unsigned long max_timeout;
        int touch_num;
        int error;

        /*
         * The 'buffer status' bit, which indicates that the data is valid, is
         * not set as soon as the interrupt is raised, but slightly after.
         * This takes around 10 ms to happen, so we poll for 20 ms.
         */
        max_timeout = jiffies + msecs_to_jiffies(GOODIX_BUFFER_STATUS_TIMEOUT);
        do {
                error = goodix_i2c_read(ts->client, GOODIX_READ_COOR_ADDR,
                                        data, GOODIX_CONTACT_SIZE + 1);
                if (error) {
                        dev_err(&ts->client->dev, "I2C transfer error: %d\n",
                                        error);
                        return error;
                }

                if (data[0] & GOODIX_BUFFER_STATUS_READY) {
                        touch_num = data[0] & 0x0f;
                        if (touch_num > ts->max_touch_num)
                                return -EPROTO;

                        if (touch_num > 1) {
                                data += 1 + GOODIX_CONTACT_SIZE;
                                error = goodix_i2c_read(ts->client,
                                                GOODIX_READ_COOR_ADDR +
                                                        1 + GOODIX_CONTACT_SIZE,
                                                data,
                                                GOODIX_CONTACT_SIZE *
                                                        (touch_num - 1));
                                if (error)
                                        return error;
                        }

                        return touch_num;
                }

                usleep_range(1000, 2000); /* Poll every 1 - 2 ms */
        } while (time_before(jiffies, max_timeout));

        /*
         * The Goodix panel will send spurious interrupts after a
         * 'finger up' event, which will always cause a timeout.
         */
        return 0;
}

static void goodix_ts_report_touch(struct goodix_ts_data *ts, u8 *coor_data)
{
        int id = coor_data[0] & 0x0F;
        int input_x = get_unaligned_le16(&coor_data[1]);
        int input_y = get_unaligned_le16(&coor_data[3]);
        int input_w = get_unaligned_le16(&coor_data[5]);

        input_mt_slot(ts->input_dev, id);
        input_mt_report_slot_state(ts->input_dev, MT_TOOL_FINGER, true);
        touchscreen_report_pos(ts->input_dev, &ts->prop,
                               input_x, input_y, true);
        input_report_abs(ts->input_dev, ABS_MT_TOUCH_MAJOR, input_w);
        input_report_abs(ts->input_dev, ABS_MT_WIDTH_MAJOR, input_w);
}

/**
 * goodix_process_events - Process incoming events
 *
 * @ts: our goodix_ts_data pointer
 *
 * Called when the IRQ is triggered. Read the current device state, and push
 * the input events to the user space.
 */
static void goodix_process_events(struct goodix_ts_data *ts)
{
        u8  point_data[1 + GOODIX_CONTACT_SIZE * GOODIX_MAX_CONTACTS];
        int touch_num;
        int i;

        touch_num = goodix_ts_read_input_report(ts, point_data);
        if (touch_num < 0)
                return;

        /*
         * Bit 4 of the first byte reports the status of the capacitive
         * Windows/Home button.
         */
        input_report_key(ts->input_dev, KEY_LEFTMETA, point_data[0] & BIT(4));

        for (i = 0; i < touch_num; i++)
                goodix_ts_report_touch(ts,
                                &point_data[1 + GOODIX_CONTACT_SIZE * i]);

        input_mt_sync_frame(ts->input_dev);
        input_sync(ts->input_dev);
}

/**
 * goodix_ts_irq_handler - The IRQ handler
 *
 * @irq: interrupt number.
 * @dev_id: private data pointer.
 */
static irqreturn_t goodix_ts_irq_handler(int irq, void *dev_id)
{
        struct goodix_ts_data *ts = dev_id;

        goodix_process_events(ts);

        if (goodix_i2c_write_u8(ts->client, GOODIX_READ_COOR_ADDR, 0) < 0)
                dev_err(&ts->client->dev, "I2C write end_cmd error\n");

        return IRQ_HANDLED;
}

static void goodix_free_irq(struct goodix_ts_data *ts)
{
        devm_free_irq(&ts->client->dev, ts->client->irq, ts);
}

static int goodix_request_irq(struct goodix_ts_data *ts)
{
        return devm_request_threaded_irq(&ts->client->dev, ts->client->irq,
                                         NULL, goodix_ts_irq_handler,
                                         ts->irq_flags, ts->client->name, ts);
}

static int goodix_check_cfg_8(struct goodix_ts_data *ts,
                        const struct firmware *cfg)
{
        int i, raw_cfg_len = cfg->size - 2;
        u8 check_sum = 0;

        for (i = 0; i < raw_cfg_len; i++)
                check_sum += cfg->data[i];
        check_sum = (~check_sum) + 1;
        if (check_sum != cfg->data[raw_cfg_len]) {
                dev_err(&ts->client->dev,
                        "The checksum of the config fw is not correct");
                return -EINVAL;
        }

        if (cfg->data[raw_cfg_len + 1] != 1) {
                dev_err(&ts->client->dev,
                        "Config fw must have Config_Fresh register set");
                return -EINVAL;
        }

        return 0;
}

static int goodix_check_cfg_16(struct goodix_ts_data *ts,
                        const struct firmware *cfg)
{
        int i, raw_cfg_len = cfg->size - 3;
        u16 check_sum = 0;

        for (i = 0; i < raw_cfg_len; i += 2)
                check_sum += get_unaligned_be16(&cfg->data[i]);
        check_sum = (~check_sum) + 1;
        if (check_sum != get_unaligned_be16(&cfg->data[raw_cfg_len])) {
                dev_err(&ts->client->dev,
                        "The checksum of the config fw is not correct");
                return -EINVAL;
        }

        if (cfg->data[raw_cfg_len + 2] != 1) {
                dev_err(&ts->client->dev,
                        "Config fw must have Config_Fresh register set");
                return -EINVAL;
        }

        return 0;
}

/**
 * goodix_check_cfg - Checks if config fw is valid
 *
 * @ts: goodix_ts_data pointer
 * @cfg: firmware config data
 */
static int goodix_check_cfg(struct goodix_ts_data *ts,
                            const struct firmware *cfg)
{
        if (cfg->size > GOODIX_CONFIG_MAX_LENGTH) {
                dev_err(&ts->client->dev,
                        "The length of the config fw is not correct");
                return -EINVAL;
        }

        return ts->chip->check_config(ts, cfg);
}

/**
 * goodix_send_cfg - Write fw config to device
 *
 * @ts: goodix_ts_data pointer
 * @cfg: config firmware to write to device
 */
static int goodix_send_cfg(struct goodix_ts_data *ts,
                           const struct firmware *cfg)
{
        int error;

        error = goodix_check_cfg(ts, cfg);
        if (error)
                return error;

        error = goodix_i2c_write(ts->client, ts->chip->config_addr, cfg->data,
                                 cfg->size);
        if (error) {
                dev_err(&ts->client->dev, "Failed to write config data: %d",
                        error);
                return error;
        }
        dev_dbg(&ts->client->dev, "Config sent successfully.");

        /* Let the firmware reconfigure itself, so sleep for 10ms */
        usleep_range(10000, 11000);

        return 0;
}

static int goodix_int_sync(struct goodix_ts_data *ts)
{
        int error;

        error = gpiod_direction_output(ts->gpiod_int, 0);
        if (error)
                return error;

        msleep(50);                             /* T5: 50ms */

        error = gpiod_direction_input(ts->gpiod_int);
        if (error)
                return error;

        return 0;
}

/**
 * goodix_reset - Reset device during power on
 *
 * @ts: goodix_ts_data pointer
 */
static int goodix_reset(struct goodix_ts_data *ts)
{
        int error;

        /* begin select I2C slave addr */
        error = gpiod_direction_output(ts->gpiod_rst, 0);
        if (error)
                return error;

        msleep(20);                             /* T2: > 10ms */

        /* HIGH: 0x28/0x29, LOW: 0xBA/0xBB */
        error = gpiod_direction_output(ts->gpiod_int, ts->client->addr == 0x14);
        if (error)
                return error;

        usleep_range(100, 2000);                /* T3: > 100us */

        error = gpiod_direction_output(ts->gpiod_rst, 1);
        if (error)
                return error;

        usleep_range(6000, 10000);              /* T4: > 5ms */

        /* end select I2C slave addr */
        error = gpiod_direction_input(ts->gpiod_rst);
        if (error)
                return error;

        error = goodix_int_sync(ts);
        if (error)
                return error;

        return 0;
}

/**
 * goodix_get_gpio_config - Get GPIO config from ACPI/DT
 *
 * @ts: goodix_ts_data pointer
 */
static int goodix_get_gpio_config(struct goodix_ts_data *ts)
{
        int error;
        struct device *dev;
        struct gpio_desc *gpiod;

        if (!ts->client)
                return -EINVAL;
        dev = &ts->client->dev;

        /* Get the interrupt GPIO pin number */
        gpiod = devm_gpiod_get_optional(dev, GOODIX_GPIO_INT_NAME, GPIOD_IN);
        if (IS_ERR(gpiod)) {
                error = PTR_ERR(gpiod);
                if (error != -EPROBE_DEFER)
                        dev_dbg(dev, "Failed to get %s GPIO: %d\n",
                                GOODIX_GPIO_INT_NAME, error);
                return error;
        }

        ts->gpiod_int = gpiod;

        /* Get the reset line GPIO pin number */
        gpiod = devm_gpiod_get_optional(dev, GOODIX_GPIO_RST_NAME, GPIOD_IN);
        if (IS_ERR(gpiod)) {
                error = PTR_ERR(gpiod);
                if (error != -EPROBE_DEFER)
                        dev_dbg(dev, "Failed to get %s GPIO: %d\n",
                                GOODIX_GPIO_RST_NAME, error);
                return error;
        }

        ts->gpiod_rst = gpiod;

        return 0;
}

/**
 * goodix_read_config - Read the embedded configuration of the panel
 *
 * @ts: our goodix_ts_data pointer
 *
 * Must be called during probe
 */
static void goodix_read_config(struct goodix_ts_data *ts)
{
        u8 config[GOODIX_CONFIG_MAX_LENGTH];
        int x_max, y_max;
        int error;

        error = goodix_i2c_read(ts->client, ts->chip->config_addr,
                                config, ts->chip->config_len);
        if (error) {
                dev_warn(&ts->client->dev, "Error reading config: %d\n",
                         error);
                ts->int_trigger_type = GOODIX_INT_TRIGGER;
                ts->max_touch_num = GOODIX_MAX_CONTACTS;
                return;
        }

        ts->int_trigger_type = config[TRIGGER_LOC] & 0x03;
        ts->max_touch_num = config[MAX_CONTACTS_LOC] & 0x0f;

        x_max = get_unaligned_le16(&config[RESOLUTION_LOC]);
        y_max = get_unaligned_le16(&config[RESOLUTION_LOC + 2]);
        if (x_max && y_max) {
                input_abs_set_max(ts->input_dev, ABS_MT_POSITION_X, x_max - 1);
                input_abs_set_max(ts->input_dev, ABS_MT_POSITION_Y, y_max - 1);
        }
}

/**
 * goodix_read_version - Read goodix touchscreen version
 *
 * @ts: our goodix_ts_data pointer
 */
static int goodix_read_version(struct goodix_ts_data *ts)
{
        int error;
        u8 buf[6];
        char id_str[5];

        error = goodix_i2c_read(ts->client, GOODIX_REG_ID, buf, sizeof(buf));
        if (error) {
                dev_err(&ts->client->dev, "read version failed: %d\n", error);
                return error;
        }

        memcpy(id_str, buf, 4);
        id_str[4] = 0;
        if (kstrtou16(id_str, 10, &ts->id))
                ts->id = 0x1001;

        ts->version = get_unaligned_le16(&buf[4]);

        dev_info(&ts->client->dev, "ID %d, version: %04x\n", ts->id,
                 ts->version);

        return 0;
}

/**
 * goodix_i2c_test - I2C test function to check if the device answers.
 *
 * @client: the i2c client
 */
static int goodix_i2c_test(struct i2c_client *client)
{
        int retry = 0;
        int error;
        u8 test;

        while (retry++ < 2) {
                error = goodix_i2c_read(client, GOODIX_REG_ID,
                                        &test, 1);
                if (!error)
                        return 0;

                dev_err(&client->dev, "i2c test failed attempt %d: %d\n",
                        retry, error);
                msleep(20);
        }

        return error;
}

/**
 * goodix_configure_dev - Finish device initialization
 *
 * @ts: our goodix_ts_data pointer
 *
 * Must be called from probe to finish initialization of the device.
 * Contains the common initialization code for both devices that
 * declare gpio pins and devices that do not. It is either called
 * directly from probe or from request_firmware_wait callback.
 */
static int goodix_configure_dev(struct goodix_ts_data *ts)
{
        int error;

        ts->int_trigger_type = GOODIX_INT_TRIGGER;
        ts->max_touch_num = GOODIX_MAX_CONTACTS;

        ts->input_dev = devm_input_allocate_device(&ts->client->dev);
        if (!ts->input_dev) {
                dev_err(&ts->client->dev, "Failed to allocate input device.");
                return -ENOMEM;
        }

        ts->input_dev->name = "Goodix Capacitive TouchScreen";
        ts->input_dev->phys = "input/ts";
        ts->input_dev->id.bustype = BUS_I2C;
        ts->input_dev->id.vendor = 0x0416;
        ts->input_dev->id.product = ts->id;
        ts->input_dev->id.version = ts->version;

        /* Capacitive Windows/Home button on some devices */
        input_set_capability(ts->input_dev, EV_KEY, KEY_LEFTMETA);

        input_set_capability(ts->input_dev, EV_ABS, ABS_MT_POSITION_X);
        input_set_capability(ts->input_dev, EV_ABS, ABS_MT_POSITION_Y);
        input_set_abs_params(ts->input_dev, ABS_MT_WIDTH_MAJOR, 0, 255, 0, 0);
        input_set_abs_params(ts->input_dev, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);

        /* Read configuration and apply touchscreen parameters */
        goodix_read_config(ts);

        /* Try overriding touchscreen parameters via device properties */
        touchscreen_parse_properties(ts->input_dev, true, &ts->prop);

        if (!ts->prop.max_x || !ts->prop.max_y || !ts->max_touch_num) {
                dev_err(&ts->client->dev, "Invalid config, using defaults\n");
                ts->prop.max_x = GOODIX_MAX_WIDTH - 1;
                ts->prop.max_y = GOODIX_MAX_HEIGHT - 1;
                ts->max_touch_num = GOODIX_MAX_CONTACTS;
                input_abs_set_max(ts->input_dev,
                                  ABS_MT_POSITION_X, ts->prop.max_x);
                input_abs_set_max(ts->input_dev,
                                  ABS_MT_POSITION_Y, ts->prop.max_y);
        }

        if (dmi_check_system(rotated_screen)) {
                ts->prop.invert_x = true;
                ts->prop.invert_y = true;
                dev_dbg(&ts->client->dev,
                        "Applying '180 degrees rotated screen' quirk\n");
        }

        error = input_mt_init_slots(ts->input_dev, ts->max_touch_num,
                                    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
        if (error) {
                dev_err(&ts->client->dev,
                        "Failed to initialize MT slots: %d", error);
                return error;
        }

        error = input_register_device(ts->input_dev);
        if (error) {
                dev_err(&ts->client->dev,
                        "Failed to register input device: %d", error);
                return error;
        }

        ts->irq_flags = goodix_irq_flags[ts->int_trigger_type] | IRQF_ONESHOT;
        error = goodix_request_irq(ts);
        if (error) {
                dev_err(&ts->client->dev, "request IRQ failed: %d\n", error);
                return error;
        }

        return 0;
}

/**
 * goodix_config_cb - Callback to finish device init
 *
 * @ts: our goodix_ts_data pointer
 *
 * request_firmware_wait callback that finishes
 * initialization of the device.
 */
static void goodix_config_cb(const struct firmware *cfg, void *ctx)
{
        struct goodix_ts_data *ts = ctx;
        int error;

        if (cfg) {
                /* send device configuration to the firmware */
                error = goodix_send_cfg(ts, cfg);
                if (error)
                        goto err_release_cfg;
        }

        goodix_configure_dev(ts);

err_release_cfg:
        release_firmware(cfg);
        complete_all(&ts->firmware_loading_complete);
}

static int goodix_ts_probe(struct i2c_client *client,
                           const struct i2c_device_id *id)
{
        struct goodix_ts_data *ts;
        int error;

        dev_dbg(&client->dev, "I2C Address: 0x%02x\n", client->addr);

        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
                dev_err(&client->dev, "I2C check functionality failed.\n");
                return -ENXIO;
        }

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

        ts->client = client;
        i2c_set_clientdata(client, ts);
        init_completion(&ts->firmware_loading_complete);

        error = goodix_get_gpio_config(ts);
        if (error)
                return error;

        if (ts->gpiod_int && ts->gpiod_rst) {
                /* reset the controller */
                error = goodix_reset(ts);
                if (error) {
                        dev_err(&client->dev, "Controller reset failed.\n");
                        return error;
                }
        }

        error = goodix_i2c_test(client);
        if (error) {
                dev_err(&client->dev, "I2C communication failure: %d\n", error);
                return error;
        }

        error = goodix_read_version(ts);
        if (error) {
                dev_err(&client->dev, "Read version failed.\n");
                return error;
        }

        ts->chip = goodix_get_chip_data(ts->id);

        if (ts->gpiod_int && ts->gpiod_rst) {
                /* update device config */
                ts->cfg_name = devm_kasprintf(&client->dev, GFP_KERNEL,
                                              "goodix_%d_cfg.bin", ts->id);
                if (!ts->cfg_name)
                        return -ENOMEM;

                error = request_firmware_nowait(THIS_MODULE, true, ts->cfg_name,
                                                &client->dev, GFP_KERNEL, ts,
                                                goodix_config_cb);
                if (error) {
                        dev_err(&client->dev,
                                "Failed to invoke firmware loader: %d\n",
                                error);
                        return error;
                }

                return 0;
        } else {
                error = goodix_configure_dev(ts);
                if (error)
                        return error;
        }

        return 0;
}

static int goodix_ts_remove(struct i2c_client *client)
{
        struct goodix_ts_data *ts = i2c_get_clientdata(client);

        if (ts->gpiod_int && ts->gpiod_rst)
                wait_for_completion(&ts->firmware_loading_complete);

        return 0;
}

static int __maybe_unused goodix_suspend(struct device *dev)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct goodix_ts_data *ts = i2c_get_clientdata(client);
        int error;

        /* We need gpio pins to suspend/resume */
        if (!ts->gpiod_int || !ts->gpiod_rst) {
                disable_irq(client->irq);
                return 0;
        }

        wait_for_completion(&ts->firmware_loading_complete);

        /* Free IRQ as IRQ pin is used as output in the suspend sequence */
        goodix_free_irq(ts);

        /* Output LOW on the INT pin for 5 ms */
        error = gpiod_direction_output(ts->gpiod_int, 0);
        if (error) {
                goodix_request_irq(ts);
                return error;
        }

        usleep_range(5000, 6000);

        error = goodix_i2c_write_u8(ts->client, GOODIX_REG_COMMAND,
                                    GOODIX_CMD_SCREEN_OFF);
        if (error) {
                dev_err(&ts->client->dev, "Screen off command failed\n");
                gpiod_direction_input(ts->gpiod_int);
                goodix_request_irq(ts);
                return -EAGAIN;
        }

        /*
         * The datasheet specifies that the interval between sending screen-off
         * command and wake-up should be longer than 58 ms. To avoid waking up
         * sooner, delay 58ms here.
         */
        msleep(58);
        return 0;
}

static int __maybe_unused goodix_resume(struct device *dev)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct goodix_ts_data *ts = i2c_get_clientdata(client);
        int error;

        if (!ts->gpiod_int || !ts->gpiod_rst) {
                enable_irq(client->irq);
                return 0;
        }

        /*
         * Exit sleep mode by outputting HIGH level to INT pin
         * for 2ms~5ms.
         */
        error = gpiod_direction_output(ts->gpiod_int, 1);
        if (error)
                return error;

        usleep_range(2000, 5000);

        error = goodix_int_sync(ts);
        if (error)
                return error;

        error = goodix_request_irq(ts);
        if (error)
                return error;

        return 0;
}

static SIMPLE_DEV_PM_OPS(goodix_pm_ops, goodix_suspend, goodix_resume);

static const struct i2c_device_id goodix_ts_id[] = {
        { "GDIX1001:00", 0 },
        { }
};
MODULE_DEVICE_TABLE(i2c, goodix_ts_id);

#ifdef CONFIG_ACPI
static const struct acpi_device_id goodix_acpi_match[] = {
        { "GDIX1001", 0 },
        { }
};
MODULE_DEVICE_TABLE(acpi, goodix_acpi_match);
#endif

#ifdef CONFIG_OF
static const struct of_device_id goodix_of_match[] = {
        { .compatible = "goodix,gt1151" },
        { .compatible = "goodix,gt911" },
        { .compatible = "goodix,gt9110" },
        { .compatible = "goodix,gt912" },
        { .compatible = "goodix,gt927" },
        { .compatible = "goodix,gt9271" },
        { .compatible = "goodix,gt928" },
        { .compatible = "goodix,gt967" },
        { }
};
MODULE_DEVICE_TABLE(of, goodix_of_match);
#endif

static struct i2c_driver goodix_ts_driver = {
        .probe = goodix_ts_probe,
        .remove = goodix_ts_remove,
        .id_table = goodix_ts_id,
        .driver = {
                .name = "Goodix-TS",
                .acpi_match_table = ACPI_PTR(goodix_acpi_match),
                .of_match_table = of_match_ptr(goodix_of_match),
                .pm = &goodix_pm_ops,
        },
};
module_i2c_driver(goodix_ts_driver);

MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
MODULE_AUTHOR("Bastien Nocera <hadess@hadess.net>");
MODULE_DESCRIPTION("Goodix touchscreen driver");
MODULE_LICENSE("GPL v2");