1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Touchscreen driver for WM831x PMICs
4 *
5 * Copyright 2011 Wolfson Microelectronics plc.
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7 */
8
9 #include <linux/module.h>
10 #include <linux/moduleparam.h>
11 #include <linux/kernel.h>
12 #include <linux/string.h>
13 #include <linux/pm.h>
14 #include <linux/input.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/mfd/wm831x/core.h>
18 #include <linux/mfd/wm831x/irq.h>
19 #include <linux/mfd/wm831x/pdata.h>
20 #include <linux/platform_device.h>
21 #include <linux/slab.h>
22 #include <linux/types.h>
23
24 /*
25 * R16424 (0x4028) - Touch Control 1
26 */
27 #define WM831X_TCH_ENA 0x8000 /* TCH_ENA */
28 #define WM831X_TCH_CVT_ENA 0x4000 /* TCH_CVT_ENA */
29 #define WM831X_TCH_SLPENA 0x1000 /* TCH_SLPENA */
30 #define WM831X_TCH_Z_ENA 0x0400 /* TCH_Z_ENA */
31 #define WM831X_TCH_Y_ENA 0x0200 /* TCH_Y_ENA */
32 #define WM831X_TCH_X_ENA 0x0100 /* TCH_X_ENA */
33 #define WM831X_TCH_DELAY_MASK 0x00E0 /* TCH_DELAY - [7:5] */
34 #define WM831X_TCH_DELAY_SHIFT 5 /* TCH_DELAY - [7:5] */
35 #define WM831X_TCH_DELAY_WIDTH 3 /* TCH_DELAY - [7:5] */
36 #define WM831X_TCH_RATE_MASK 0x001F /* TCH_RATE - [4:0] */
37 #define WM831X_TCH_RATE_SHIFT 0 /* TCH_RATE - [4:0] */
38 #define WM831X_TCH_RATE_WIDTH 5 /* TCH_RATE - [4:0] */
39
40 /*
41 * R16425 (0x4029) - Touch Control 2
42 */
43 #define WM831X_TCH_PD_WK 0x2000 /* TCH_PD_WK */
44 #define WM831X_TCH_5WIRE 0x1000 /* TCH_5WIRE */
45 #define WM831X_TCH_PDONLY 0x0800 /* TCH_PDONLY */
46 #define WM831X_TCH_ISEL 0x0100 /* TCH_ISEL */
47 #define WM831X_TCH_RPU_MASK 0x000F /* TCH_RPU - [3:0] */
48 #define WM831X_TCH_RPU_SHIFT 0 /* TCH_RPU - [3:0] */
49 #define WM831X_TCH_RPU_WIDTH 4 /* TCH_RPU - [3:0] */
50
51 /*
52 * R16426-8 (0x402A-C) - Touch Data X/Y/X
53 */
54 #define WM831X_TCH_PD 0x8000 /* TCH_PD1 */
55 #define WM831X_TCH_DATA_MASK 0x0FFF /* TCH_DATA - [11:0] */
56 #define WM831X_TCH_DATA_SHIFT 0 /* TCH_DATA - [11:0] */
57 #define WM831X_TCH_DATA_WIDTH 12 /* TCH_DATA - [11:0] */
58
59 struct wm831x_ts {
60 struct input_dev *input_dev;
61 struct wm831x *wm831x;
62 unsigned int data_irq;
63 unsigned int pd_irq;
64 bool pressure;
65 bool pen_down;
66 struct work_struct pd_data_work;
67 };
68
wm831x_pd_data_work(struct work_struct * work)69 static void wm831x_pd_data_work(struct work_struct *work)
70 {
71 struct wm831x_ts *wm831x_ts =
72 container_of(work, struct wm831x_ts, pd_data_work);
73
74 if (wm831x_ts->pen_down) {
75 enable_irq(wm831x_ts->data_irq);
76 dev_dbg(wm831x_ts->wm831x->dev, "IRQ PD->DATA done\n");
77 } else {
78 enable_irq(wm831x_ts->pd_irq);
79 dev_dbg(wm831x_ts->wm831x->dev, "IRQ DATA->PD done\n");
80 }
81 }
82
wm831x_ts_data_irq(int irq,void * irq_data)83 static irqreturn_t wm831x_ts_data_irq(int irq, void *irq_data)
84 {
85 struct wm831x_ts *wm831x_ts = irq_data;
86 struct wm831x *wm831x = wm831x_ts->wm831x;
87 static int data_types[] = { ABS_X, ABS_Y, ABS_PRESSURE };
88 u16 data[3];
89 int count;
90 int i, ret;
91
92 if (wm831x_ts->pressure)
93 count = 3;
94 else
95 count = 2;
96
97 wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
98 WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
99
100 ret = wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count,
101 data);
102 if (ret != 0) {
103 dev_err(wm831x->dev, "Failed to read touch data: %d\n",
104 ret);
105 return IRQ_NONE;
106 }
107
108 /*
109 * We get a pen down reading on every reading, report pen up if any
110 * individual reading does so.
111 */
112 wm831x_ts->pen_down = true;
113 for (i = 0; i < count; i++) {
114 if (!(data[i] & WM831X_TCH_PD)) {
115 wm831x_ts->pen_down = false;
116 continue;
117 }
118 input_report_abs(wm831x_ts->input_dev, data_types[i],
119 data[i] & WM831X_TCH_DATA_MASK);
120 }
121
122 if (!wm831x_ts->pen_down) {
123 /* Switch from data to pen down */
124 dev_dbg(wm831x->dev, "IRQ DATA->PD\n");
125
126 disable_irq_nosync(wm831x_ts->data_irq);
127
128 /* Don't need data any more */
129 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
130 WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
131 WM831X_TCH_Z_ENA, 0);
132
133 /* Flush any final samples that arrived while reading */
134 wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
135 WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
136
137 wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count, data);
138
139 if (wm831x_ts->pressure)
140 input_report_abs(wm831x_ts->input_dev,
141 ABS_PRESSURE, 0);
142
143 input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 0);
144
145 schedule_work(&wm831x_ts->pd_data_work);
146 } else {
147 input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 1);
148 }
149
150 input_sync(wm831x_ts->input_dev);
151
152 return IRQ_HANDLED;
153 }
154
wm831x_ts_pen_down_irq(int irq,void * irq_data)155 static irqreturn_t wm831x_ts_pen_down_irq(int irq, void *irq_data)
156 {
157 struct wm831x_ts *wm831x_ts = irq_data;
158 struct wm831x *wm831x = wm831x_ts->wm831x;
159 int ena = 0;
160
161 if (wm831x_ts->pen_down)
162 return IRQ_HANDLED;
163
164 disable_irq_nosync(wm831x_ts->pd_irq);
165
166 /* Start collecting data */
167 if (wm831x_ts->pressure)
168 ena |= WM831X_TCH_Z_ENA;
169
170 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
171 WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA,
172 WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | ena);
173
174 wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
175 WM831X_TCHPD_EINT, WM831X_TCHPD_EINT);
176
177 wm831x_ts->pen_down = true;
178
179 /* Switch from pen down to data */
180 dev_dbg(wm831x->dev, "IRQ PD->DATA\n");
181 schedule_work(&wm831x_ts->pd_data_work);
182
183 return IRQ_HANDLED;
184 }
185
wm831x_ts_input_open(struct input_dev * idev)186 static int wm831x_ts_input_open(struct input_dev *idev)
187 {
188 struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
189 struct wm831x *wm831x = wm831x_ts->wm831x;
190
191 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
192 WM831X_TCH_ENA | WM831X_TCH_CVT_ENA |
193 WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
194 WM831X_TCH_Z_ENA, WM831X_TCH_ENA);
195
196 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
197 WM831X_TCH_CVT_ENA, WM831X_TCH_CVT_ENA);
198
199 return 0;
200 }
201
wm831x_ts_input_close(struct input_dev * idev)202 static void wm831x_ts_input_close(struct input_dev *idev)
203 {
204 struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
205 struct wm831x *wm831x = wm831x_ts->wm831x;
206
207 /* Shut the controller down, disabling all other functionality too */
208 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
209 WM831X_TCH_ENA | WM831X_TCH_X_ENA |
210 WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA, 0);
211
212 /* Make sure any pending IRQs are done, the above will prevent
213 * new ones firing.
214 */
215 synchronize_irq(wm831x_ts->data_irq);
216 synchronize_irq(wm831x_ts->pd_irq);
217
218 /* Make sure the IRQ completion work is quiesced */
219 flush_work(&wm831x_ts->pd_data_work);
220
221 /* If we ended up with the pen down then make sure we revert back
222 * to pen detection state for the next time we start up.
223 */
224 if (wm831x_ts->pen_down) {
225 disable_irq(wm831x_ts->data_irq);
226 enable_irq(wm831x_ts->pd_irq);
227 wm831x_ts->pen_down = false;
228 }
229 }
230
wm831x_ts_probe(struct platform_device * pdev)231 static int wm831x_ts_probe(struct platform_device *pdev)
232 {
233 struct wm831x_ts *wm831x_ts;
234 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
235 struct wm831x_pdata *core_pdata = dev_get_platdata(pdev->dev.parent);
236 struct wm831x_touch_pdata *pdata = NULL;
237 struct input_dev *input_dev;
238 int error, irqf;
239
240 if (core_pdata)
241 pdata = core_pdata->touch;
242
243 wm831x_ts = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_ts),
244 GFP_KERNEL);
245 input_dev = devm_input_allocate_device(&pdev->dev);
246 if (!wm831x_ts || !input_dev) {
247 error = -ENOMEM;
248 goto err_alloc;
249 }
250
251 wm831x_ts->wm831x = wm831x;
252 wm831x_ts->input_dev = input_dev;
253 INIT_WORK(&wm831x_ts->pd_data_work, wm831x_pd_data_work);
254
255 /*
256 * If we have a direct IRQ use it, otherwise use the interrupt
257 * from the WM831x IRQ controller.
258 */
259 wm831x_ts->data_irq = wm831x_irq(wm831x,
260 platform_get_irq_byname(pdev,
261 "TCHDATA"));
262 if (pdata && pdata->data_irq)
263 wm831x_ts->data_irq = pdata->data_irq;
264
265 wm831x_ts->pd_irq = wm831x_irq(wm831x,
266 platform_get_irq_byname(pdev, "TCHPD"));
267 if (pdata && pdata->pd_irq)
268 wm831x_ts->pd_irq = pdata->pd_irq;
269
270 if (pdata)
271 wm831x_ts->pressure = pdata->pressure;
272 else
273 wm831x_ts->pressure = true;
274
275 /* Five wire touchscreens can't report pressure */
276 if (pdata && pdata->fivewire) {
277 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
278 WM831X_TCH_5WIRE, WM831X_TCH_5WIRE);
279
280 /* Pressure measurements are not possible for five wire mode */
281 WARN_ON(pdata->pressure && pdata->fivewire);
282 wm831x_ts->pressure = false;
283 } else {
284 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
285 WM831X_TCH_5WIRE, 0);
286 }
287
288 if (pdata) {
289 switch (pdata->isel) {
290 default:
291 dev_err(&pdev->dev, "Unsupported ISEL setting: %d\n",
292 pdata->isel);
293 fallthrough;
294 case 200:
295 case 0:
296 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
297 WM831X_TCH_ISEL, 0);
298 break;
299 case 400:
300 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
301 WM831X_TCH_ISEL, WM831X_TCH_ISEL);
302 break;
303 }
304 }
305
306 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
307 WM831X_TCH_PDONLY, 0);
308
309 /* Default to 96 samples/sec */
310 wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
311 WM831X_TCH_RATE_MASK, 6);
312
313 if (pdata && pdata->data_irqf)
314 irqf = pdata->data_irqf;
315 else
316 irqf = IRQF_TRIGGER_HIGH;
317
318 error = request_threaded_irq(wm831x_ts->data_irq,
319 NULL, wm831x_ts_data_irq,
320 irqf | IRQF_ONESHOT | IRQF_NO_AUTOEN,
321 "Touchscreen data", wm831x_ts);
322 if (error) {
323 dev_err(&pdev->dev, "Failed to request data IRQ %d: %d\n",
324 wm831x_ts->data_irq, error);
325 goto err_alloc;
326 }
327
328 if (pdata && pdata->pd_irqf)
329 irqf = pdata->pd_irqf;
330 else
331 irqf = IRQF_TRIGGER_HIGH;
332
333 error = request_threaded_irq(wm831x_ts->pd_irq,
334 NULL, wm831x_ts_pen_down_irq,
335 irqf | IRQF_ONESHOT,
336 "Touchscreen pen down", wm831x_ts);
337 if (error) {
338 dev_err(&pdev->dev, "Failed to request pen down IRQ %d: %d\n",
339 wm831x_ts->pd_irq, error);
340 goto err_data_irq;
341 }
342
343 /* set up touch configuration */
344 input_dev->name = "WM831x touchscreen";
345 input_dev->phys = "wm831x";
346 input_dev->open = wm831x_ts_input_open;
347 input_dev->close = wm831x_ts_input_close;
348
349 __set_bit(EV_ABS, input_dev->evbit);
350 __set_bit(EV_KEY, input_dev->evbit);
351 __set_bit(BTN_TOUCH, input_dev->keybit);
352
353 input_set_abs_params(input_dev, ABS_X, 0, 4095, 5, 0);
354 input_set_abs_params(input_dev, ABS_Y, 0, 4095, 5, 0);
355 if (wm831x_ts->pressure)
356 input_set_abs_params(input_dev, ABS_PRESSURE, 0, 4095, 5, 0);
357
358 input_set_drvdata(input_dev, wm831x_ts);
359 input_dev->dev.parent = &pdev->dev;
360
361 error = input_register_device(input_dev);
362 if (error)
363 goto err_pd_irq;
364
365 platform_set_drvdata(pdev, wm831x_ts);
366 return 0;
367
368 err_pd_irq:
369 free_irq(wm831x_ts->pd_irq, wm831x_ts);
370 err_data_irq:
371 free_irq(wm831x_ts->data_irq, wm831x_ts);
372 err_alloc:
373
374 return error;
375 }
376
wm831x_ts_remove(struct platform_device * pdev)377 static int wm831x_ts_remove(struct platform_device *pdev)
378 {
379 struct wm831x_ts *wm831x_ts = platform_get_drvdata(pdev);
380
381 free_irq(wm831x_ts->pd_irq, wm831x_ts);
382 free_irq(wm831x_ts->data_irq, wm831x_ts);
383
384 return 0;
385 }
386
387 static struct platform_driver wm831x_ts_driver = {
388 .driver = {
389 .name = "wm831x-touch",
390 },
391 .probe = wm831x_ts_probe,
392 .remove = wm831x_ts_remove,
393 };
394 module_platform_driver(wm831x_ts_driver);
395
396 /* Module information */
397 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
398 MODULE_DESCRIPTION("WM831x PMIC touchscreen driver");
399 MODULE_LICENSE("GPL");
400 MODULE_ALIAS("platform:wm831x-touch");
401