Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
wm831x-ts.c
Go to the documentation of this file.
1 /*
2  * Touchscreen driver for WM831x PMICs
3  *
4  * Copyright 2011 Wolfson Microelectronics plc.
5  * Author: Mark Brown <[email protected]>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License as published by the
9  * Free Software Foundation; either version 2 of the License, or (at your
10  * option) any later version.
11  */
12 
13 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 #include <linux/kernel.h>
16 #include <linux/init.h>
17 #include <linux/string.h>
18 #include <linux/pm.h>
19 #include <linux/input.h>
20 #include <linux/interrupt.h>
21 #include <linux/io.h>
22 #include <linux/mfd/wm831x/core.h>
23 #include <linux/mfd/wm831x/irq.h>
24 #include <linux/mfd/wm831x/pdata.h>
25 #include <linux/platform_device.h>
26 #include <linux/slab.h>
27 #include <linux/types.h>
28 
29 /*
30  * R16424 (0x4028) - Touch Control 1
31  */
32 #define WM831X_TCH_ENA 0x8000 /* TCH_ENA */
33 #define WM831X_TCH_CVT_ENA 0x4000 /* TCH_CVT_ENA */
34 #define WM831X_TCH_SLPENA 0x1000 /* TCH_SLPENA */
35 #define WM831X_TCH_Z_ENA 0x0400 /* TCH_Z_ENA */
36 #define WM831X_TCH_Y_ENA 0x0200 /* TCH_Y_ENA */
37 #define WM831X_TCH_X_ENA 0x0100 /* TCH_X_ENA */
38 #define WM831X_TCH_DELAY_MASK 0x00E0 /* TCH_DELAY - [7:5] */
39 #define WM831X_TCH_DELAY_SHIFT 5 /* TCH_DELAY - [7:5] */
40 #define WM831X_TCH_DELAY_WIDTH 3 /* TCH_DELAY - [7:5] */
41 #define WM831X_TCH_RATE_MASK 0x001F /* TCH_RATE - [4:0] */
42 #define WM831X_TCH_RATE_SHIFT 0 /* TCH_RATE - [4:0] */
43 #define WM831X_TCH_RATE_WIDTH 5 /* TCH_RATE - [4:0] */
44 
45 /*
46  * R16425 (0x4029) - Touch Control 2
47  */
48 #define WM831X_TCH_PD_WK 0x2000 /* TCH_PD_WK */
49 #define WM831X_TCH_5WIRE 0x1000 /* TCH_5WIRE */
50 #define WM831X_TCH_PDONLY 0x0800 /* TCH_PDONLY */
51 #define WM831X_TCH_ISEL 0x0100 /* TCH_ISEL */
52 #define WM831X_TCH_RPU_MASK 0x000F /* TCH_RPU - [3:0] */
53 #define WM831X_TCH_RPU_SHIFT 0 /* TCH_RPU - [3:0] */
54 #define WM831X_TCH_RPU_WIDTH 4 /* TCH_RPU - [3:0] */
55 
56 /*
57  * R16426-8 (0x402A-C) - Touch Data X/Y/X
58  */
59 #define WM831X_TCH_PD 0x8000 /* TCH_PD1 */
60 #define WM831X_TCH_DATA_MASK 0x0FFF /* TCH_DATA - [11:0] */
61 #define WM831X_TCH_DATA_SHIFT 0 /* TCH_DATA - [11:0] */
62 #define WM831X_TCH_DATA_WIDTH 12 /* TCH_DATA - [11:0] */
63 
64 struct wm831x_ts {
65  struct input_dev *input_dev;
66  struct wm831x *wm831x;
67  unsigned int data_irq;
68  unsigned int pd_irq;
69  bool pressure;
70  bool pen_down;
71  struct work_struct pd_data_work;
72 };
73 
74 static void wm831x_pd_data_work(struct work_struct *work)
75 {
76  struct wm831x_ts *wm831x_ts =
77  container_of(work, struct wm831x_ts, pd_data_work);
78 
79  if (wm831x_ts->pen_down) {
80  enable_irq(wm831x_ts->data_irq);
81  dev_dbg(wm831x_ts->wm831x->dev, "IRQ PD->DATA done\n");
82  } else {
83  enable_irq(wm831x_ts->pd_irq);
84  dev_dbg(wm831x_ts->wm831x->dev, "IRQ DATA->PD done\n");
85  }
86 }
87 
88 static irqreturn_t wm831x_ts_data_irq(int irq, void *irq_data)
89 {
90  struct wm831x_ts *wm831x_ts = irq_data;
91  struct wm831x *wm831x = wm831x_ts->wm831x;
92  static int data_types[] = { ABS_X, ABS_Y, ABS_PRESSURE };
93  u16 data[3];
94  int count;
95  int i, ret;
96 
97  if (wm831x_ts->pressure)
98  count = 3;
99  else
100  count = 2;
101 
102  wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
103  WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
104 
105  ret = wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count,
106  data);
107  if (ret != 0) {
108  dev_err(wm831x->dev, "Failed to read touch data: %d\n",
109  ret);
110  return IRQ_NONE;
111  }
112 
113  /*
114  * We get a pen down reading on every reading, report pen up if any
115  * individual reading does so.
116  */
117  wm831x_ts->pen_down = true;
118  for (i = 0; i < count; i++) {
119  if (!(data[i] & WM831X_TCH_PD)) {
120  wm831x_ts->pen_down = false;
121  continue;
122  }
123  input_report_abs(wm831x_ts->input_dev, data_types[i],
124  data[i] & WM831X_TCH_DATA_MASK);
125  }
126 
127  if (!wm831x_ts->pen_down) {
128  /* Switch from data to pen down */
129  dev_dbg(wm831x->dev, "IRQ DATA->PD\n");
130 
131  disable_irq_nosync(wm831x_ts->data_irq);
132 
133  /* Don't need data any more */
134  wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
135  WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
136  WM831X_TCH_Z_ENA, 0);
137 
138  /* Flush any final samples that arrived while reading */
139  wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
140  WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
141 
142  wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count, data);
143 
144  if (wm831x_ts->pressure)
145  input_report_abs(wm831x_ts->input_dev,
146  ABS_PRESSURE, 0);
147 
148  input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 0);
149 
150  schedule_work(&wm831x_ts->pd_data_work);
151  } else {
152  input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 1);
153  }
154 
155  input_sync(wm831x_ts->input_dev);
156 
157  return IRQ_HANDLED;
158 }
159 
160 static irqreturn_t wm831x_ts_pen_down_irq(int irq, void *irq_data)
161 {
162  struct wm831x_ts *wm831x_ts = irq_data;
163  struct wm831x *wm831x = wm831x_ts->wm831x;
164  int ena = 0;
165 
166  if (wm831x_ts->pen_down)
167  return IRQ_HANDLED;
168 
169  disable_irq_nosync(wm831x_ts->pd_irq);
170 
171  /* Start collecting data */
172  if (wm831x_ts->pressure)
173  ena |= WM831X_TCH_Z_ENA;
174 
175  wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
176  WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA,
177  WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | ena);
178 
179  wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
180  WM831X_TCHPD_EINT, WM831X_TCHPD_EINT);
181 
182  wm831x_ts->pen_down = true;
183 
184  /* Switch from pen down to data */
185  dev_dbg(wm831x->dev, "IRQ PD->DATA\n");
186  schedule_work(&wm831x_ts->pd_data_work);
187 
188  return IRQ_HANDLED;
189 }
190 
191 static int wm831x_ts_input_open(struct input_dev *idev)
192 {
193  struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
194  struct wm831x *wm831x = wm831x_ts->wm831x;
195 
196  wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
197  WM831X_TCH_ENA | WM831X_TCH_CVT_ENA |
198  WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
199  WM831X_TCH_Z_ENA, WM831X_TCH_ENA);
200 
201  wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
202  WM831X_TCH_CVT_ENA, WM831X_TCH_CVT_ENA);
203 
204  return 0;
205 }
206 
207 static void wm831x_ts_input_close(struct input_dev *idev)
208 {
209  struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
210  struct wm831x *wm831x = wm831x_ts->wm831x;
211 
212  /* Shut the controller down, disabling all other functionality too */
213  wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
214  WM831X_TCH_ENA | WM831X_TCH_X_ENA |
215  WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA, 0);
216 
217  /* Make sure any pending IRQs are done, the above will prevent
218  * new ones firing.
219  */
220  synchronize_irq(wm831x_ts->data_irq);
221  synchronize_irq(wm831x_ts->pd_irq);
222 
223  /* Make sure the IRQ completion work is quiesced */
224  flush_work(&wm831x_ts->pd_data_work);
225 
226  /* If we ended up with the pen down then make sure we revert back
227  * to pen detection state for the next time we start up.
228  */
229  if (wm831x_ts->pen_down) {
230  disable_irq(wm831x_ts->data_irq);
231  enable_irq(wm831x_ts->pd_irq);
232  wm831x_ts->pen_down = false;
233  }
234 }
235 
236 static __devinit int wm831x_ts_probe(struct platform_device *pdev)
237 {
238  struct wm831x_ts *wm831x_ts;
239  struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
240  struct wm831x_pdata *core_pdata = dev_get_platdata(pdev->dev.parent);
241  struct wm831x_touch_pdata *pdata = NULL;
242  struct input_dev *input_dev;
243  int error, irqf;
244 
245  if (core_pdata)
246  pdata = core_pdata->touch;
247 
248  wm831x_ts = kzalloc(sizeof(struct wm831x_ts), GFP_KERNEL);
249  input_dev = input_allocate_device();
250  if (!wm831x_ts || !input_dev) {
251  error = -ENOMEM;
252  goto err_alloc;
253  }
254 
255  wm831x_ts->wm831x = wm831x;
256  wm831x_ts->input_dev = input_dev;
257  INIT_WORK(&wm831x_ts->pd_data_work, wm831x_pd_data_work);
258 
259  /*
260  * If we have a direct IRQ use it, otherwise use the interrupt
261  * from the WM831x IRQ controller.
262  */
263  wm831x_ts->data_irq = wm831x_irq(wm831x,
264  platform_get_irq_byname(pdev,
265  "TCHDATA"));
266  if (pdata && pdata->data_irq)
267  wm831x_ts->data_irq = pdata->data_irq;
268 
269  wm831x_ts->pd_irq = wm831x_irq(wm831x,
270  platform_get_irq_byname(pdev, "TCHPD"));
271  if (pdata && pdata->pd_irq)
272  wm831x_ts->pd_irq = pdata->pd_irq;
273 
274  if (pdata)
275  wm831x_ts->pressure = pdata->pressure;
276  else
277  wm831x_ts->pressure = true;
278 
279  /* Five wire touchscreens can't report pressure */
280  if (pdata && pdata->fivewire) {
281  wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
282  WM831X_TCH_5WIRE, WM831X_TCH_5WIRE);
283 
284  /* Pressure measurements are not possible for five wire mode */
285  WARN_ON(pdata->pressure && pdata->fivewire);
286  wm831x_ts->pressure = false;
287  } else {
288  wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
289  WM831X_TCH_5WIRE, 0);
290  }
291 
292  if (pdata) {
293  switch (pdata->isel) {
294  default:
295  dev_err(&pdev->dev, "Unsupported ISEL setting: %d\n",
296  pdata->isel);
297  /* Fall through */
298  case 200:
299  case 0:
300  wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
301  WM831X_TCH_ISEL, 0);
302  break;
303  case 400:
304  wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
305  WM831X_TCH_ISEL, WM831X_TCH_ISEL);
306  break;
307  }
308  }
309 
310  wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
311  WM831X_TCH_PDONLY, 0);
312 
313  /* Default to 96 samples/sec */
314  wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
315  WM831X_TCH_RATE_MASK, 6);
316 
317  if (pdata && pdata->data_irqf)
318  irqf = pdata->data_irqf;
319  else
320  irqf = IRQF_TRIGGER_HIGH;
321 
322  error = request_threaded_irq(wm831x_ts->data_irq,
323  NULL, wm831x_ts_data_irq,
324  irqf | IRQF_ONESHOT,
325  "Touchscreen data", wm831x_ts);
326  if (error) {
327  dev_err(&pdev->dev, "Failed to request data IRQ %d: %d\n",
328  wm831x_ts->data_irq, error);
329  goto err_alloc;
330  }
331  disable_irq(wm831x_ts->data_irq);
332 
333  if (pdata && pdata->pd_irqf)
334  irqf = pdata->pd_irqf;
335  else
336  irqf = IRQF_TRIGGER_HIGH;
337 
338  error = request_threaded_irq(wm831x_ts->pd_irq,
339  NULL, wm831x_ts_pen_down_irq,
340  irqf | IRQF_ONESHOT,
341  "Touchscreen pen down", wm831x_ts);
342  if (error) {
343  dev_err(&pdev->dev, "Failed to request pen down IRQ %d: %d\n",
344  wm831x_ts->pd_irq, error);
345  goto err_data_irq;
346  }
347 
348  /* set up touch configuration */
349  input_dev->name = "WM831x touchscreen";
350  input_dev->phys = "wm831x";
351  input_dev->open = wm831x_ts_input_open;
352  input_dev->close = wm831x_ts_input_close;
353 
354  __set_bit(EV_ABS, input_dev->evbit);
355  __set_bit(EV_KEY, input_dev->evbit);
356  __set_bit(BTN_TOUCH, input_dev->keybit);
357 
358  input_set_abs_params(input_dev, ABS_X, 0, 4095, 5, 0);
359  input_set_abs_params(input_dev, ABS_Y, 0, 4095, 5, 0);
360  if (wm831x_ts->pressure)
361  input_set_abs_params(input_dev, ABS_PRESSURE, 0, 4095, 5, 0);
362 
363  input_set_drvdata(input_dev, wm831x_ts);
364  input_dev->dev.parent = &pdev->dev;
365 
366  error = input_register_device(input_dev);
367  if (error)
368  goto err_pd_irq;
369 
370  platform_set_drvdata(pdev, wm831x_ts);
371  return 0;
372 
373 err_pd_irq:
374  free_irq(wm831x_ts->pd_irq, wm831x_ts);
375 err_data_irq:
376  free_irq(wm831x_ts->data_irq, wm831x_ts);
377 err_alloc:
378  input_free_device(input_dev);
379  kfree(wm831x_ts);
380 
381  return error;
382 }
383 
384 static __devexit int wm831x_ts_remove(struct platform_device *pdev)
385 {
386  struct wm831x_ts *wm831x_ts = platform_get_drvdata(pdev);
387 
388  free_irq(wm831x_ts->pd_irq, wm831x_ts);
389  free_irq(wm831x_ts->data_irq, wm831x_ts);
390  input_unregister_device(wm831x_ts->input_dev);
391  kfree(wm831x_ts);
392 
393  platform_set_drvdata(pdev, NULL);
394  return 0;
395 }
396 
397 static struct platform_driver wm831x_ts_driver = {
398  .driver = {
399  .name = "wm831x-touch",
400  .owner = THIS_MODULE,
401  },
402  .probe = wm831x_ts_probe,
403  .remove = __devexit_p(wm831x_ts_remove),
404 };
405 module_platform_driver(wm831x_ts_driver);
406 
407 /* Module information */
408 MODULE_AUTHOR("Mark Brown <[email protected]>");
409 MODULE_DESCRIPTION("WM831x PMIC touchscreen driver");
410 MODULE_LICENSE("GPL");
411 MODULE_ALIAS("platform:wm831x-touch");
Generated on Thu Jan 10 2013 13:40:27 for Linux Kernel by   doxygen 1.8.2