// SPDX-License-Identifier: GPL-2.0-only
/*
 * Driver for cypress touch screen controller
 *
 * Copyright (c) 2009 Aava Mobile
 *
 * Some cleanups by Alan Cox <alan@linux.intel.com>
 */

#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/gpio/consumer.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <asm/byteorder.h>

#define CY8CTMG110_DRIVER_NAME      "cy8ctmg110"

/* Touch coordinates */
#define CY8CTMG110_X_MIN                0
#define CY8CTMG110_Y_MIN                0
#define CY8CTMG110_X_MAX                759
#define CY8CTMG110_Y_MAX                465


/* cy8ctmg110 register definitions */
#define CY8CTMG110_TOUCH_WAKEUP_TIME    0
#define CY8CTMG110_TOUCH_SLEEP_TIME     2
#define CY8CTMG110_TOUCH_X1             3
#define CY8CTMG110_TOUCH_Y1             5
#define CY8CTMG110_TOUCH_X2             7
#define CY8CTMG110_TOUCH_Y2             9
#define CY8CTMG110_FINGERS              11
#define CY8CTMG110_GESTURE              12
#define CY8CTMG110_REG_MAX              13


/*
 * The touch driver structure.
 */
struct cy8ctmg110 {
        struct input_dev *input;
        char phys[32];
        struct i2c_client *client;
        struct gpio_desc *reset_gpio;
};

/*
 * cy8ctmg110_power is the routine that is called when touch hardware
 * is being powered off or on. When powering on this routine de-asserts
 * the RESET line, when powering off reset line is asserted.
 */
static void cy8ctmg110_power(struct cy8ctmg110 *ts, bool poweron)
{
        if (ts->reset_gpio)
                gpiod_set_value_cansleep(ts->reset_gpio, !poweron);
}

static int cy8ctmg110_write_regs(struct cy8ctmg110 *tsc, unsigned char reg,
                unsigned char len, unsigned char *value)
{
        struct i2c_client *client = tsc->client;
        int ret;
        unsigned char i2c_data[6];

        BUG_ON(len > 5);

        i2c_data[0] = reg;
        memcpy(i2c_data + 1, value, len);

        ret = i2c_master_send(client, i2c_data, len + 1);
        if (ret != len + 1) {
                dev_err(&client->dev, "i2c write data cmd failed\n");
                return ret < 0 ? ret : -EIO;
        }

        return 0;
}

static int cy8ctmg110_read_regs(struct cy8ctmg110 *tsc,
                unsigned char *data, unsigned char len, unsigned char cmd)
{
        struct i2c_client *client = tsc->client;
        int ret;
        struct i2c_msg msg[2] = {
                /* first write slave position to i2c devices */
                {
                        .addr = client->addr,
                        .len = 1,
                        .buf = &cmd
                },
                /* Second read data from position */
                {
                        .addr = client->addr,
                        .flags = I2C_M_RD,
                        .len = len,
                        .buf = data
                }
        };

        ret = i2c_transfer(client->adapter, msg, 2);
        if (ret < 0)
                return ret;

        return 0;
}

static int cy8ctmg110_touch_pos(struct cy8ctmg110 *tsc)
{
        struct input_dev *input = tsc->input;
        unsigned char reg_p[CY8CTMG110_REG_MAX];

        memset(reg_p, 0, CY8CTMG110_REG_MAX);

        /* Reading coordinates */
        if (cy8ctmg110_read_regs(tsc, reg_p, 9, CY8CTMG110_TOUCH_X1) != 0)
                return -EIO;

        /* Number of touch */
        if (reg_p[8] == 0) {
                input_report_key(input, BTN_TOUCH, 0);
        } else  {
                input_report_key(input, BTN_TOUCH, 1);
                input_report_abs(input, ABS_X,
                                 be16_to_cpup((__be16 *)(reg_p + 0)));
                input_report_abs(input, ABS_Y,
                                 be16_to_cpup((__be16 *)(reg_p + 2)));
        }

        input_sync(input);

        return 0;
}

static int cy8ctmg110_set_sleepmode(struct cy8ctmg110 *ts, bool sleep)
{
        unsigned char reg_p[3];

        if (sleep) {
                reg_p[0] = 0x00;
                reg_p[1] = 0xff;
                reg_p[2] = 5;
        } else {
                reg_p[0] = 0x10;
                reg_p[1] = 0xff;
                reg_p[2] = 0;
        }

        return cy8ctmg110_write_regs(ts, CY8CTMG110_TOUCH_WAKEUP_TIME, 3, reg_p);
}

static irqreturn_t cy8ctmg110_irq_thread(int irq, void *dev_id)
{
        struct cy8ctmg110 *tsc = dev_id;

        cy8ctmg110_touch_pos(tsc);

        return IRQ_HANDLED;
}

static void cy8ctmg110_shut_off(void *_ts)
{
        struct cy8ctmg110 *ts = _ts;

        cy8ctmg110_set_sleepmode(ts, true);
        cy8ctmg110_power(ts, false);
}

static int cy8ctmg110_probe(struct i2c_client *client)
{
        struct cy8ctmg110 *ts;
        struct input_dev *input_dev;
        int err;

        if (!i2c_check_functionality(client->adapter,
                                        I2C_FUNC_SMBUS_READ_WORD_DATA))
                return -EIO;

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

        input_dev = devm_input_allocate_device(&client->dev);
        if (!input_dev)
                return -ENOMEM;

        ts->client = client;
        ts->input = input_dev;

        snprintf(ts->phys, sizeof(ts->phys),
                 "%s/input0", dev_name(&client->dev));

        input_dev->name = CY8CTMG110_DRIVER_NAME " Touchscreen";
        input_dev->phys = ts->phys;
        input_dev->id.bustype = BUS_I2C;

        input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
        input_set_abs_params(input_dev, ABS_X,
                        CY8CTMG110_X_MIN, CY8CTMG110_X_MAX, 4, 0);
        input_set_abs_params(input_dev, ABS_Y,
                        CY8CTMG110_Y_MIN, CY8CTMG110_Y_MAX, 4, 0);

        /* Request and assert reset line */
        ts->reset_gpio = devm_gpiod_get_optional(&client->dev, NULL,
                                                 GPIOD_OUT_HIGH);
        if (IS_ERR(ts->reset_gpio)) {
                err = PTR_ERR(ts->reset_gpio);
                dev_err(&client->dev,
                        "Unable to request reset GPIO: %d\n", err);
                return err;
        }

        cy8ctmg110_power(ts, true);
        cy8ctmg110_set_sleepmode(ts, false);

        err = devm_add_action_or_reset(&client->dev, cy8ctmg110_shut_off, ts);
        if (err)
                return err;

        err = devm_request_threaded_irq(&client->dev, client->irq,
                                        NULL, cy8ctmg110_irq_thread,
                                        IRQF_ONESHOT, "touch_reset_key", ts);
        if (err) {
                dev_err(&client->dev,
                        "irq %d busy? error %d\n", client->irq, err);
                return err;
        }

        err = input_register_device(input_dev);
        if (err)
                return err;

        i2c_set_clientdata(client, ts);

        return 0;
}

static int cy8ctmg110_suspend(struct device *dev)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct cy8ctmg110 *ts = i2c_get_clientdata(client);

        if (!device_may_wakeup(&client->dev)) {
                cy8ctmg110_set_sleepmode(ts, true);
                cy8ctmg110_power(ts, false);
        }

        return 0;
}

static int cy8ctmg110_resume(struct device *dev)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct cy8ctmg110 *ts = i2c_get_clientdata(client);

        if (!device_may_wakeup(&client->dev)) {
                cy8ctmg110_power(ts, true);
                cy8ctmg110_set_sleepmode(ts, false);
        }

        return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(cy8ctmg110_pm,
                                cy8ctmg110_suspend, cy8ctmg110_resume);

static const struct i2c_device_id cy8ctmg110_idtable[] = {
        { .name = CY8CTMG110_DRIVER_NAME, .driver_data = 1 },
        { }
};

MODULE_DEVICE_TABLE(i2c, cy8ctmg110_idtable);

static struct i2c_driver cy8ctmg110_driver = {
        .driver         = {
                .name   = CY8CTMG110_DRIVER_NAME,
                .pm     = pm_sleep_ptr(&cy8ctmg110_pm),
        },
        .id_table       = cy8ctmg110_idtable,
        .probe          = cy8ctmg110_probe,
};

module_i2c_driver(cy8ctmg110_driver);

MODULE_AUTHOR("Samuli Konttila <samuli.konttila@aavamobile.com>");
MODULE_DESCRIPTION("cy8ctmg110 TouchScreen Driver");
MODULE_LICENSE("GPL v2");