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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