// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Touchscreen driver for WM831x PMICs
 *
 * Copyright 2011 Wolfson Microelectronics plc.
 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/pm.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/mfd/wm831x/core.h>
#include <linux/mfd/wm831x/irq.h>
#include <linux/mfd/wm831x/pdata.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/types.h>

/*
 * R16424 (0x4028) - Touch Control 1
 */
#define WM831X_TCH_ENA                          0x8000  /* TCH_ENA */
#define WM831X_TCH_CVT_ENA                      0x4000  /* TCH_CVT_ENA */
#define WM831X_TCH_SLPENA                       0x1000  /* TCH_SLPENA */
#define WM831X_TCH_Z_ENA                        0x0400  /* TCH_Z_ENA */
#define WM831X_TCH_Y_ENA                        0x0200  /* TCH_Y_ENA */
#define WM831X_TCH_X_ENA                        0x0100  /* TCH_X_ENA */
#define WM831X_TCH_DELAY_MASK                   0x00E0  /* TCH_DELAY - [7:5] */
#define WM831X_TCH_DELAY_SHIFT                       5  /* TCH_DELAY - [7:5] */
#define WM831X_TCH_DELAY_WIDTH                       3  /* TCH_DELAY - [7:5] */
#define WM831X_TCH_RATE_MASK                    0x001F  /* TCH_RATE - [4:0] */
#define WM831X_TCH_RATE_SHIFT                        0  /* TCH_RATE - [4:0] */
#define WM831X_TCH_RATE_WIDTH                        5  /* TCH_RATE - [4:0] */

/*
 * R16425 (0x4029) - Touch Control 2
 */
#define WM831X_TCH_PD_WK                        0x2000  /* TCH_PD_WK */
#define WM831X_TCH_5WIRE                        0x1000  /* TCH_5WIRE */
#define WM831X_TCH_PDONLY                       0x0800  /* TCH_PDONLY */
#define WM831X_TCH_ISEL                         0x0100  /* TCH_ISEL */
#define WM831X_TCH_RPU_MASK                     0x000F  /* TCH_RPU - [3:0] */
#define WM831X_TCH_RPU_SHIFT                         0  /* TCH_RPU - [3:0] */
#define WM831X_TCH_RPU_WIDTH                         4  /* TCH_RPU - [3:0] */

/*
 * R16426-8 (0x402A-C) - Touch Data X/Y/X
 */
#define WM831X_TCH_PD                           0x8000  /* TCH_PD1 */
#define WM831X_TCH_DATA_MASK                    0x0FFF  /* TCH_DATA - [11:0] */
#define WM831X_TCH_DATA_SHIFT                        0  /* TCH_DATA - [11:0] */
#define WM831X_TCH_DATA_WIDTH                       12  /* TCH_DATA - [11:0] */

struct wm831x_ts {
        struct input_dev *input_dev;
        struct wm831x *wm831x;
        unsigned int data_irq;
        unsigned int pd_irq;
        bool pressure;
        bool pen_down;
        struct work_struct pd_data_work;
};

static void wm831x_pd_data_work(struct work_struct *work)
{
        struct wm831x_ts *wm831x_ts =
                container_of(work, struct wm831x_ts, pd_data_work);

        if (wm831x_ts->pen_down) {
                enable_irq(wm831x_ts->data_irq);
                dev_dbg(wm831x_ts->wm831x->dev, "IRQ PD->DATA done\n");
        } else {
                enable_irq(wm831x_ts->pd_irq);
                dev_dbg(wm831x_ts->wm831x->dev, "IRQ DATA->PD done\n");
        }
}

static irqreturn_t wm831x_ts_data_irq(int irq, void *irq_data)
{
        struct wm831x_ts *wm831x_ts = irq_data;
        struct wm831x *wm831x = wm831x_ts->wm831x;
        static int data_types[] = { ABS_X, ABS_Y, ABS_PRESSURE };
        u16 data[3];
        int count;
        int i, ret;

        if (wm831x_ts->pressure)
                count = 3;
        else
                count = 2;

        wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
                        WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);

        ret = wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count,
                               data);
        if (ret != 0) {
                dev_err(wm831x->dev, "Failed to read touch data: %d\n",
                        ret);
                return IRQ_NONE;
        }

        /*
         * We get a pen down reading on every reading, report pen up if any
         * individual reading does so.
         */
        wm831x_ts->pen_down = true;
        for (i = 0; i < count; i++) {
                if (!(data[i] & WM831X_TCH_PD)) {
                        wm831x_ts->pen_down = false;
                        continue;
                }
                input_report_abs(wm831x_ts->input_dev, data_types[i],
                                 data[i] & WM831X_TCH_DATA_MASK);
        }

        if (!wm831x_ts->pen_down) {
                /* Switch from data to pen down */
                dev_dbg(wm831x->dev, "IRQ DATA->PD\n");

                disable_irq_nosync(wm831x_ts->data_irq);

                /* Don't need data any more */
                wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
                                WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
                                WM831X_TCH_Z_ENA, 0);

                /* Flush any final samples that arrived while reading */
                wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
                                WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);

                wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count, data);

                if (wm831x_ts->pressure)
                        input_report_abs(wm831x_ts->input_dev,
                                         ABS_PRESSURE, 0);

                input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 0);

                schedule_work(&wm831x_ts->pd_data_work);
        } else {
                input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 1);
        }

        input_sync(wm831x_ts->input_dev);

        return IRQ_HANDLED;
}

static irqreturn_t wm831x_ts_pen_down_irq(int irq, void *irq_data)
{
        struct wm831x_ts *wm831x_ts = irq_data;
        struct wm831x *wm831x = wm831x_ts->wm831x;
        int ena = 0;

        if (wm831x_ts->pen_down)
                return IRQ_HANDLED;

        disable_irq_nosync(wm831x_ts->pd_irq);

        /* Start collecting data */
        if (wm831x_ts->pressure)
                ena |= WM831X_TCH_Z_ENA;

        wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
                        WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA,
                        WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | ena);

        wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
                        WM831X_TCHPD_EINT, WM831X_TCHPD_EINT);

        wm831x_ts->pen_down = true;

        /* Switch from pen down to data */
        dev_dbg(wm831x->dev, "IRQ PD->DATA\n");
        schedule_work(&wm831x_ts->pd_data_work);

        return IRQ_HANDLED;
}

static int wm831x_ts_input_open(struct input_dev *idev)
{
        struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
        struct wm831x *wm831x = wm831x_ts->wm831x;

        wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
                        WM831X_TCH_ENA | WM831X_TCH_CVT_ENA |
                        WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
                        WM831X_TCH_Z_ENA, WM831X_TCH_ENA);

        wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
                        WM831X_TCH_CVT_ENA, WM831X_TCH_CVT_ENA);

        return 0;
}

static void wm831x_ts_input_close(struct input_dev *idev)
{
        struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
        struct wm831x *wm831x = wm831x_ts->wm831x;

        /* Shut the controller down, disabling all other functionality too */
        wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
                        WM831X_TCH_ENA | WM831X_TCH_X_ENA |
                        WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA, 0);

        /* Make sure any pending IRQs are done, the above will prevent
         * new ones firing.
         */
        synchronize_irq(wm831x_ts->data_irq);
        synchronize_irq(wm831x_ts->pd_irq);

        /* Make sure the IRQ completion work is quiesced */
        flush_work(&wm831x_ts->pd_data_work);

        /* If we ended up with the pen down then make sure we revert back
         * to pen detection state for the next time we start up.
         */
        if (wm831x_ts->pen_down) {
                disable_irq(wm831x_ts->data_irq);
                enable_irq(wm831x_ts->pd_irq);
                wm831x_ts->pen_down = false;
        }
}

static int wm831x_ts_probe(struct platform_device *pdev)
{
        struct wm831x_ts *wm831x_ts;
        struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
        struct wm831x_pdata *core_pdata = dev_get_platdata(pdev->dev.parent);
        struct wm831x_touch_pdata *pdata = NULL;
        struct input_dev *input_dev;
        int error, irqf;

        if (core_pdata)
                pdata = core_pdata->touch;

        wm831x_ts = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_ts),
                                 GFP_KERNEL);
        input_dev = devm_input_allocate_device(&pdev->dev);
        if (!wm831x_ts || !input_dev) {
                error = -ENOMEM;
                goto err_alloc;
        }

        wm831x_ts->wm831x = wm831x;
        wm831x_ts->input_dev = input_dev;
        INIT_WORK(&wm831x_ts->pd_data_work, wm831x_pd_data_work);

        /*
         * If we have a direct IRQ use it, otherwise use the interrupt
         * from the WM831x IRQ controller.
         */
        wm831x_ts->data_irq = wm831x_irq(wm831x,
                                         platform_get_irq_byname(pdev,
                                                                 "TCHDATA"));
        if (pdata && pdata->data_irq)
                wm831x_ts->data_irq = pdata->data_irq;

        wm831x_ts->pd_irq = wm831x_irq(wm831x,
                                       platform_get_irq_byname(pdev, "TCHPD"));
        if (pdata && pdata->pd_irq)
                wm831x_ts->pd_irq = pdata->pd_irq;

        if (pdata)
                wm831x_ts->pressure = pdata->pressure;
        else
                wm831x_ts->pressure = true;

        /* Five wire touchscreens can't report pressure */
        if (pdata && pdata->fivewire) {
                wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
                                WM831X_TCH_5WIRE, WM831X_TCH_5WIRE);

                /* Pressure measurements are not possible for five wire mode */
                WARN_ON(pdata->pressure && pdata->fivewire);
                wm831x_ts->pressure = false;
        } else {
                wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
                                WM831X_TCH_5WIRE, 0);
        }

        if (pdata) {
                switch (pdata->isel) {
                default:
                        dev_err(&pdev->dev, "Unsupported ISEL setting: %d\n",
                                pdata->isel);
                        fallthrough;
                case 200:
                case 0:
                        wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
                                        WM831X_TCH_ISEL, 0);
                        break;
                case 400:
                        wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
                                        WM831X_TCH_ISEL, WM831X_TCH_ISEL);
                        break;
                }
        }

        wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
                        WM831X_TCH_PDONLY, 0);

        /* Default to 96 samples/sec */
        wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
                        WM831X_TCH_RATE_MASK, 6);

        if (pdata && pdata->data_irqf)
                irqf = pdata->data_irqf;
        else
                irqf = IRQF_TRIGGER_HIGH;

        error = request_threaded_irq(wm831x_ts->data_irq,
                                     NULL, wm831x_ts_data_irq,
                                     irqf | IRQF_ONESHOT | IRQF_NO_AUTOEN,
                                     "Touchscreen data", wm831x_ts);
        if (error) {
                dev_err(&pdev->dev, "Failed to request data IRQ %d: %d\n",
                        wm831x_ts->data_irq, error);
                goto err_alloc;
        }

        if (pdata && pdata->pd_irqf)
                irqf = pdata->pd_irqf;
        else
                irqf = IRQF_TRIGGER_HIGH;

        error = request_threaded_irq(wm831x_ts->pd_irq,
                                     NULL, wm831x_ts_pen_down_irq,
                                     irqf | IRQF_ONESHOT,
                                     "Touchscreen pen down", wm831x_ts);
        if (error) {
                dev_err(&pdev->dev, "Failed to request pen down IRQ %d: %d\n",
                        wm831x_ts->pd_irq, error);
                goto err_data_irq;
        }

        /* set up touch configuration */
        input_dev->name = "WM831x touchscreen";
        input_dev->phys = "wm831x";
        input_dev->open = wm831x_ts_input_open;
        input_dev->close = wm831x_ts_input_close;

        __set_bit(EV_ABS, input_dev->evbit);
        __set_bit(EV_KEY, input_dev->evbit);
        __set_bit(BTN_TOUCH, input_dev->keybit);

        input_set_abs_params(input_dev, ABS_X, 0, 4095, 5, 0);
        input_set_abs_params(input_dev, ABS_Y, 0, 4095, 5, 0);
        if (wm831x_ts->pressure)
                input_set_abs_params(input_dev, ABS_PRESSURE, 0, 4095, 5, 0);

        input_set_drvdata(input_dev, wm831x_ts);
        input_dev->dev.parent = &pdev->dev;

        error = input_register_device(input_dev);
        if (error)
                goto err_pd_irq;

        platform_set_drvdata(pdev, wm831x_ts);
        return 0;

err_pd_irq:
        free_irq(wm831x_ts->pd_irq, wm831x_ts);
err_data_irq:
        free_irq(wm831x_ts->data_irq, wm831x_ts);
err_alloc:

        return error;
}

static void wm831x_ts_remove(struct platform_device *pdev)
{
        struct wm831x_ts *wm831x_ts = platform_get_drvdata(pdev);

        free_irq(wm831x_ts->pd_irq, wm831x_ts);
        free_irq(wm831x_ts->data_irq, wm831x_ts);
}

static struct platform_driver wm831x_ts_driver = {
        .driver = {
                .name = "wm831x-touch",
        },
        .probe = wm831x_ts_probe,
        .remove = wm831x_ts_remove,
};
module_platform_driver(wm831x_ts_driver);

/* Module information */
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("WM831x PMIC touchscreen driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm831x-touch");