1 /*
2 * Touchscreen driver for WM831x PMICs
3 *
4 * Copyright 2011 Wolfson Microelectronics plc.
5 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
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/string.h>
17 #include <linux/pm.h>
18 #include <linux/input.h>
19 #include <linux/interrupt.h>
20 #include <linux/io.h>
21 #include <linux/mfd/wm831x/core.h>
22 #include <linux/mfd/wm831x/irq.h>
23 #include <linux/mfd/wm831x/pdata.h>
24 #include <linux/platform_device.h>
25 #include <linux/slab.h>
26 #include <linux/types.h>
27
28 /*
29 * R16424 (0x4028) - Touch Control 1
30 */
31 #define WM831X_TCH_ENA 0x8000 /* TCH_ENA */
32 #define WM831X_TCH_CVT_ENA 0x4000 /* TCH_CVT_ENA */
33 #define WM831X_TCH_SLPENA 0x1000 /* TCH_SLPENA */
34 #define WM831X_TCH_Z_ENA 0x0400 /* TCH_Z_ENA */
35 #define WM831X_TCH_Y_ENA 0x0200 /* TCH_Y_ENA */
36 #define WM831X_TCH_X_ENA 0x0100 /* TCH_X_ENA */
37 #define WM831X_TCH_DELAY_MASK 0x00E0 /* TCH_DELAY - [7:5] */
38 #define WM831X_TCH_DELAY_SHIFT 5 /* TCH_DELAY - [7:5] */
39 #define WM831X_TCH_DELAY_WIDTH 3 /* TCH_DELAY - [7:5] */
40 #define WM831X_TCH_RATE_MASK 0x001F /* TCH_RATE - [4:0] */
41 #define WM831X_TCH_RATE_SHIFT 0 /* TCH_RATE - [4:0] */
42 #define WM831X_TCH_RATE_WIDTH 5 /* TCH_RATE - [4:0] */
43
44 /*
45 * R16425 (0x4029) - Touch Control 2
46 */
47 #define WM831X_TCH_PD_WK 0x2000 /* TCH_PD_WK */
48 #define WM831X_TCH_5WIRE 0x1000 /* TCH_5WIRE */
49 #define WM831X_TCH_PDONLY 0x0800 /* TCH_PDONLY */
50 #define WM831X_TCH_ISEL 0x0100 /* TCH_ISEL */
51 #define WM831X_TCH_RPU_MASK 0x000F /* TCH_RPU - [3:0] */
52 #define WM831X_TCH_RPU_SHIFT 0 /* TCH_RPU - [3:0] */
53 #define WM831X_TCH_RPU_WIDTH 4 /* TCH_RPU - [3:0] */
54
55 /*
56 * R16426-8 (0x402A-C) - Touch Data X/Y/X
57 */
58 #define WM831X_TCH_PD 0x8000 /* TCH_PD1 */
59 #define WM831X_TCH_DATA_MASK 0x0FFF /* TCH_DATA - [11:0] */
60 #define WM831X_TCH_DATA_SHIFT 0 /* TCH_DATA - [11:0] */
61 #define WM831X_TCH_DATA_WIDTH 12 /* TCH_DATA - [11:0] */
62
63 struct wm831x_ts {
64 struct input_dev *input_dev;
65 struct wm831x *wm831x;
66 unsigned int data_irq;
67 unsigned int pd_irq;
68 bool pressure;
69 bool pen_down;
70 struct work_struct pd_data_work;
71 };
72
wm831x_pd_data_work(struct work_struct * work)73 static void wm831x_pd_data_work(struct work_struct *work)
74 {
75 struct wm831x_ts *wm831x_ts =
76 container_of(work, struct wm831x_ts, pd_data_work);
77
78 if (wm831x_ts->pen_down) {
79 enable_irq(wm831x_ts->data_irq);
80 dev_dbg(wm831x_ts->wm831x->dev, "IRQ PD->DATA done\n");
81 } else {
82 enable_irq(wm831x_ts->pd_irq);
83 dev_dbg(wm831x_ts->wm831x->dev, "IRQ DATA->PD done\n");
84 }
85 }
86
wm831x_ts_data_irq(int irq,void * irq_data)87 static irqreturn_t wm831x_ts_data_irq(int irq, void *irq_data)
88 {
89 struct wm831x_ts *wm831x_ts = irq_data;
90 struct wm831x *wm831x = wm831x_ts->wm831x;
91 static int data_types[] = { ABS_X, ABS_Y, ABS_PRESSURE };
92 u16 data[3];
93 int count;
94 int i, ret;
95
96 if (wm831x_ts->pressure)
97 count = 3;
98 else
99 count = 2;
100
101 wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
102 WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
103
104 ret = wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count,
105 data);
106 if (ret != 0) {
107 dev_err(wm831x->dev, "Failed to read touch data: %d\n",
108 ret);
109 return IRQ_NONE;
110 }
111
112 /*
113 * We get a pen down reading on every reading, report pen up if any
114 * individual reading does so.
115 */
116 wm831x_ts->pen_down = true;
117 for (i = 0; i < count; i++) {
118 if (!(data[i] & WM831X_TCH_PD)) {
119 wm831x_ts->pen_down = false;
120 continue;
121 }
122 input_report_abs(wm831x_ts->input_dev, data_types[i],
123 data[i] & WM831X_TCH_DATA_MASK);
124 }
125
126 if (!wm831x_ts->pen_down) {
127 /* Switch from data to pen down */
128 dev_dbg(wm831x->dev, "IRQ DATA->PD\n");
129
130 disable_irq_nosync(wm831x_ts->data_irq);
131
132 /* Don't need data any more */
133 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
134 WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
135 WM831X_TCH_Z_ENA, 0);
136
137 /* Flush any final samples that arrived while reading */
138 wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
139 WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
140
141 wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count, data);
142
143 if (wm831x_ts->pressure)
144 input_report_abs(wm831x_ts->input_dev,
145 ABS_PRESSURE, 0);
146
147 input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 0);
148
149 schedule_work(&wm831x_ts->pd_data_work);
150 } else {
151 input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 1);
152 }
153
154 input_sync(wm831x_ts->input_dev);
155
156 return IRQ_HANDLED;
157 }
158
wm831x_ts_pen_down_irq(int irq,void * irq_data)159 static irqreturn_t wm831x_ts_pen_down_irq(int irq, void *irq_data)
160 {
161 struct wm831x_ts *wm831x_ts = irq_data;
162 struct wm831x *wm831x = wm831x_ts->wm831x;
163 int ena = 0;
164
165 if (wm831x_ts->pen_down)
166 return IRQ_HANDLED;
167
168 disable_irq_nosync(wm831x_ts->pd_irq);
169
170 /* Start collecting data */
171 if (wm831x_ts->pressure)
172 ena |= WM831X_TCH_Z_ENA;
173
174 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
175 WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA,
176 WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | ena);
177
178 wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
179 WM831X_TCHPD_EINT, WM831X_TCHPD_EINT);
180
181 wm831x_ts->pen_down = true;
182
183 /* Switch from pen down to data */
184 dev_dbg(wm831x->dev, "IRQ PD->DATA\n");
185 schedule_work(&wm831x_ts->pd_data_work);
186
187 return IRQ_HANDLED;
188 }
189
wm831x_ts_input_open(struct input_dev * idev)190 static int wm831x_ts_input_open(struct input_dev *idev)
191 {
192 struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
193 struct wm831x *wm831x = wm831x_ts->wm831x;
194
195 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
196 WM831X_TCH_ENA | WM831X_TCH_CVT_ENA |
197 WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
198 WM831X_TCH_Z_ENA, WM831X_TCH_ENA);
199
200 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
201 WM831X_TCH_CVT_ENA, WM831X_TCH_CVT_ENA);
202
203 return 0;
204 }
205
wm831x_ts_input_close(struct input_dev * idev)206 static void wm831x_ts_input_close(struct input_dev *idev)
207 {
208 struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
209 struct wm831x *wm831x = wm831x_ts->wm831x;
210
211 /* Shut the controller down, disabling all other functionality too */
212 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
213 WM831X_TCH_ENA | WM831X_TCH_X_ENA |
214 WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA, 0);
215
216 /* Make sure any pending IRQs are done, the above will prevent
217 * new ones firing.
218 */
219 synchronize_irq(wm831x_ts->data_irq);
220 synchronize_irq(wm831x_ts->pd_irq);
221
222 /* Make sure the IRQ completion work is quiesced */
223 flush_work(&wm831x_ts->pd_data_work);
224
225 /* If we ended up with the pen down then make sure we revert back
226 * to pen detection state for the next time we start up.
227 */
228 if (wm831x_ts->pen_down) {
229 disable_irq(wm831x_ts->data_irq);
230 enable_irq(wm831x_ts->pd_irq);
231 wm831x_ts->pen_down = false;
232 }
233 }
234
wm831x_ts_probe(struct platform_device * pdev)235 static int wm831x_ts_probe(struct platform_device *pdev)
236 {
237 struct wm831x_ts *wm831x_ts;
238 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
239 struct wm831x_pdata *core_pdata = dev_get_platdata(pdev->dev.parent);
240 struct wm831x_touch_pdata *pdata = NULL;
241 struct input_dev *input_dev;
242 int error, irqf;
243
244 if (core_pdata)
245 pdata = core_pdata->touch;
246
247 wm831x_ts = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_ts),
248 GFP_KERNEL);
249 input_dev = devm_input_allocate_device(&pdev->dev);
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
379 return error;
380 }
381
wm831x_ts_remove(struct platform_device * pdev)382 static int wm831x_ts_remove(struct platform_device *pdev)
383 {
384 struct wm831x_ts *wm831x_ts = platform_get_drvdata(pdev);
385
386 free_irq(wm831x_ts->pd_irq, wm831x_ts);
387 free_irq(wm831x_ts->data_irq, wm831x_ts);
388
389 return 0;
390 }
391
392 static struct platform_driver wm831x_ts_driver = {
393 .driver = {
394 .name = "wm831x-touch",
395 },
396 .probe = wm831x_ts_probe,
397 .remove = wm831x_ts_remove,
398 };
399 module_platform_driver(wm831x_ts_driver);
400
401 /* Module information */
402 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
403 MODULE_DESCRIPTION("WM831x PMIC touchscreen driver");
404 MODULE_LICENSE("GPL");
405 MODULE_ALIAS("platform:wm831x-touch");
406
