root/drivers/input/touchscreen/88pm860x-ts.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Touchscreen driver for Marvell 88PM860x
 *
 * Copyright (C) 2009 Marvell International Ltd.
 *      Haojian Zhuang <haojian.zhuang@marvell.com>
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/mfd/88pm860x.h>
#include <linux/slab.h>
#include <linux/device.h>

#define MEAS_LEN                (8)
#define ACCURATE_BIT            (12)

/* touch register */
#define MEAS_EN3                (0x52)

#define MEAS_TSIX_1             (0x8D)
#define MEAS_TSIX_2             (0x8E)
#define MEAS_TSIY_1             (0x8F)
#define MEAS_TSIY_2             (0x90)
#define MEAS_TSIZ1_1            (0x91)
#define MEAS_TSIZ1_2            (0x92)
#define MEAS_TSIZ2_1            (0x93)
#define MEAS_TSIZ2_2            (0x94)

/* bit definitions of touch */
#define MEAS_PD_EN              (1 << 3)
#define MEAS_TSIX_EN            (1 << 4)
#define MEAS_TSIY_EN            (1 << 5)
#define MEAS_TSIZ1_EN           (1 << 6)
#define MEAS_TSIZ2_EN           (1 << 7)

struct pm860x_touch {
        struct input_dev *idev;
        struct i2c_client *i2c;
        struct pm860x_chip *chip;
        int irq;
        int res_x;              /* resistor of Xplate */
};

static irqreturn_t pm860x_touch_handler(int irq, void *data)
{
        struct pm860x_touch *touch = data;
        struct pm860x_chip *chip = touch->chip;
        unsigned char buf[MEAS_LEN];
        int x, y, pen_down;
        int z1, z2, rt = 0;
        int ret;

        ret = pm860x_bulk_read(touch->i2c, MEAS_TSIX_1, MEAS_LEN, buf);
        if (ret < 0)
                goto out;

        pen_down = buf[1] & (1 << 6);
        x = ((buf[0] & 0xFF) << 4) | (buf[1] & 0x0F);
        y = ((buf[2] & 0xFF) << 4) | (buf[3] & 0x0F);
        z1 = ((buf[4] & 0xFF) << 4) | (buf[5] & 0x0F);
        z2 = ((buf[6] & 0xFF) << 4) | (buf[7] & 0x0F);

        if (pen_down) {
                if ((x != 0) && (z1 != 0) && (touch->res_x != 0)) {
                        rt = z2 / z1 - 1;
                        rt = (rt * touch->res_x * x) >> ACCURATE_BIT;
                        dev_dbg(chip->dev, "z1:%d, z2:%d, rt:%d\n",
                                z1, z2, rt);
                }
                input_report_abs(touch->idev, ABS_X, x);
                input_report_abs(touch->idev, ABS_Y, y);
                input_report_abs(touch->idev, ABS_PRESSURE, rt);
                input_report_key(touch->idev, BTN_TOUCH, 1);
                dev_dbg(chip->dev, "pen down at [%d, %d].\n", x, y);
        } else {
                input_report_abs(touch->idev, ABS_PRESSURE, 0);
                input_report_key(touch->idev, BTN_TOUCH, 0);
                dev_dbg(chip->dev, "pen release\n");
        }
        input_sync(touch->idev);

out:
        return IRQ_HANDLED;
}

static int pm860x_touch_open(struct input_dev *dev)
{
        struct pm860x_touch *touch = input_get_drvdata(dev);
        int data, ret;

        data = MEAS_PD_EN | MEAS_TSIX_EN | MEAS_TSIY_EN
                | MEAS_TSIZ1_EN | MEAS_TSIZ2_EN;
        ret = pm860x_set_bits(touch->i2c, MEAS_EN3, data, data);
        if (ret < 0)
                goto out;
        return 0;
out:
        return ret;
}

static void pm860x_touch_close(struct input_dev *dev)
{
        struct pm860x_touch *touch = input_get_drvdata(dev);
        int data;

        data = MEAS_PD_EN | MEAS_TSIX_EN | MEAS_TSIY_EN
                | MEAS_TSIZ1_EN | MEAS_TSIZ2_EN;
        pm860x_set_bits(touch->i2c, MEAS_EN3, data, 0);
}

#ifdef CONFIG_OF
static int pm860x_touch_dt_init(struct platform_device *pdev,
                                          struct pm860x_chip *chip,
                                          int *res_x)
{
        struct i2c_client *i2c = (chip->id == CHIP_PM8607) ? chip->client \
                                 : chip->companion;
        int data, n, ret;
        if (!pdev->dev.parent->of_node)
                return -ENODEV;

        struct device_node *np __free(device_node) =
                of_get_child_by_name(pdev->dev.parent->of_node, "touch");
        if (!np) {
                dev_err(&pdev->dev, "Can't find touch node\n");
                return -EINVAL;
        }
        /* set GPADC MISC1 register */
        data = 0;
        if (!of_property_read_u32(np, "marvell,88pm860x-gpadc-prebias", &n))
                data |= (n << 1) & PM8607_GPADC_PREBIAS_MASK;
        if (!of_property_read_u32(np, "marvell,88pm860x-gpadc-slot-cycle", &n))
                data |= (n << 3) & PM8607_GPADC_SLOT_CYCLE_MASK;
        if (!of_property_read_u32(np, "marvell,88pm860x-gpadc-off-scale", &n))
                data |= (n << 5) & PM8607_GPADC_OFF_SCALE_MASK;
        if (!of_property_read_u32(np, "marvell,88pm860x-gpadc-sw-cal", &n))
                data |= (n << 7) & PM8607_GPADC_SW_CAL_MASK;
        if (data) {
                ret = pm860x_reg_write(i2c, PM8607_GPADC_MISC1, data);
                if (ret < 0)
                        return -EINVAL;
        }
        /* set tsi prebias time */
        if (!of_property_read_u32(np, "marvell,88pm860x-tsi-prebias", &data)) {
                ret = pm860x_reg_write(i2c, PM8607_TSI_PREBIAS, data);
                if (ret < 0)
                        return -EINVAL;
        }
        /* set prebias & prechg time of pen detect */
        data = 0;
        if (!of_property_read_u32(np, "marvell,88pm860x-pen-prebias", &n))
                data |= n & PM8607_PD_PREBIAS_MASK;
        if (!of_property_read_u32(np, "marvell,88pm860x-pen-prechg", &n))
                data |= n & PM8607_PD_PRECHG_MASK;
        if (data) {
                ret = pm860x_reg_write(i2c, PM8607_PD_PREBIAS, data);
                if (ret < 0)
                        return -EINVAL;
        }
        of_property_read_u32(np, "marvell,88pm860x-resistor-X", res_x);

        return 0;
}
#else
#define pm860x_touch_dt_init(x, y, z)   (-1)
#endif

static int pm860x_touch_probe(struct platform_device *pdev)
{
        struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
        struct pm860x_touch_pdata *pdata = dev_get_platdata(&pdev->dev);
        struct pm860x_touch *touch;
        struct i2c_client *i2c = (chip->id == CHIP_PM8607) ? chip->client \
                                 : chip->companion;
        int irq, ret, res_x = 0, data = 0;

        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                return -EINVAL;

        if (pm860x_touch_dt_init(pdev, chip, &res_x)) {
                if (pdata) {
                        /* set GPADC MISC1 register */
                        data = 0;
                        data |= (pdata->gpadc_prebias << 1)
                                & PM8607_GPADC_PREBIAS_MASK;
                        data |= (pdata->slot_cycle << 3)
                                & PM8607_GPADC_SLOT_CYCLE_MASK;
                        data |= (pdata->off_scale << 5)
                                & PM8607_GPADC_OFF_SCALE_MASK;
                        data |= (pdata->sw_cal << 7)
                                & PM8607_GPADC_SW_CAL_MASK;
                        if (data) {
                                ret = pm860x_reg_write(i2c,
                                        PM8607_GPADC_MISC1, data);
                                if (ret < 0)
                                        return -EINVAL;
                        }
                        /* set tsi prebias time */
                        if (pdata->tsi_prebias) {
                                data = pdata->tsi_prebias;
                                ret = pm860x_reg_write(i2c,
                                        PM8607_TSI_PREBIAS, data);
                                if (ret < 0)
                                        return -EINVAL;
                        }
                        /* set prebias & prechg time of pen detect */
                        data = 0;
                        data |= pdata->pen_prebias
                                & PM8607_PD_PREBIAS_MASK;
                        data |= (pdata->pen_prechg << 5)
                                & PM8607_PD_PRECHG_MASK;
                        if (data) {
                                ret = pm860x_reg_write(i2c,
                                        PM8607_PD_PREBIAS, data);
                                if (ret < 0)
                                        return -EINVAL;
                        }
                        res_x = pdata->res_x;
                } else {
                        dev_err(&pdev->dev, "failed to get platform data\n");
                        return -EINVAL;
                }
        }
        /* enable GPADC */
        ret = pm860x_set_bits(i2c, PM8607_GPADC_MISC1, PM8607_GPADC_EN,
                              PM8607_GPADC_EN);
        if (ret)
                return ret;

        touch = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_touch),
                             GFP_KERNEL);
        if (!touch)
                return -ENOMEM;

        touch->idev = devm_input_allocate_device(&pdev->dev);
        if (!touch->idev) {
                dev_err(&pdev->dev, "Failed to allocate input device!\n");
                return -ENOMEM;
        }

        touch->idev->name = "88pm860x-touch";
        touch->idev->phys = "88pm860x/input0";
        touch->idev->id.bustype = BUS_I2C;
        touch->idev->dev.parent = &pdev->dev;
        touch->idev->open = pm860x_touch_open;
        touch->idev->close = pm860x_touch_close;
        touch->chip = chip;
        touch->i2c = i2c;
        touch->irq = irq;
        touch->res_x = res_x;
        input_set_drvdata(touch->idev, touch);

        ret = devm_request_threaded_irq(&pdev->dev, touch->irq, NULL,
                                        pm860x_touch_handler, IRQF_ONESHOT,
                                        "touch", touch);
        if (ret < 0)
                return ret;

        __set_bit(EV_ABS, touch->idev->evbit);
        __set_bit(ABS_X, touch->idev->absbit);
        __set_bit(ABS_Y, touch->idev->absbit);
        __set_bit(ABS_PRESSURE, touch->idev->absbit);
        __set_bit(EV_SYN, touch->idev->evbit);
        __set_bit(EV_KEY, touch->idev->evbit);
        __set_bit(BTN_TOUCH, touch->idev->keybit);

        input_set_abs_params(touch->idev, ABS_X, 0, 1 << ACCURATE_BIT, 0, 0);
        input_set_abs_params(touch->idev, ABS_Y, 0, 1 << ACCURATE_BIT, 0, 0);
        input_set_abs_params(touch->idev, ABS_PRESSURE, 0, 1 << ACCURATE_BIT,
                                0, 0);

        ret = input_register_device(touch->idev);
        if (ret < 0) {
                dev_err(chip->dev, "Failed to register touch!\n");
                return ret;
        }

        return 0;
}

static struct platform_driver pm860x_touch_driver = {
        .driver = {
                .name   = "88pm860x-touch",
        },
        .probe  = pm860x_touch_probe,
};
module_platform_driver(pm860x_touch_driver);

MODULE_DESCRIPTION("Touchscreen driver for Marvell Semiconductor 88PM860x");
MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:88pm860x-touch");