Quelle  wm831x-ts.c   Sprache: C

// 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 ");
MODULE_DESCRIPTION("WM831x PMIC touchscreen driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm831x-touch");