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/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 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 = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_ts),
249 				 GFP_KERNEL);
250 	input_dev = devm_input_allocate_device(&pdev->dev);
251 	if (!wm831x_ts || !input_dev) {
252 		error = -ENOMEM;
253 		goto err_alloc;
254 	}
255 
256 	wm831x_ts->wm831x = wm831x;
257 	wm831x_ts->input_dev = input_dev;
258 	INIT_WORK(&wm831x_ts->pd_data_work, wm831x_pd_data_work);
259 
260 	/*
261 	 * If we have a direct IRQ use it, otherwise use the interrupt
262 	 * from the WM831x IRQ controller.
263 	 */
264 	wm831x_ts->data_irq = wm831x_irq(wm831x,
265 					 platform_get_irq_byname(pdev,
266 								 "TCHDATA"));
267 	if (pdata && pdata->data_irq)
268 		wm831x_ts->data_irq = pdata->data_irq;
269 
270 	wm831x_ts->pd_irq = wm831x_irq(wm831x,
271 				       platform_get_irq_byname(pdev, "TCHPD"));
272 	if (pdata && pdata->pd_irq)
273 		wm831x_ts->pd_irq = pdata->pd_irq;
274 
275 	if (pdata)
276 		wm831x_ts->pressure = pdata->pressure;
277 	else
278 		wm831x_ts->pressure = true;
279 
280 	/* Five wire touchscreens can't report pressure */
281 	if (pdata && pdata->fivewire) {
282 		wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
283 				WM831X_TCH_5WIRE, WM831X_TCH_5WIRE);
284 
285 		/* Pressure measurements are not possible for five wire mode */
286 		WARN_ON(pdata->pressure && pdata->fivewire);
287 		wm831x_ts->pressure = false;
288 	} else {
289 		wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
290 				WM831X_TCH_5WIRE, 0);
291 	}
292 
293 	if (pdata) {
294 		switch (pdata->isel) {
295 		default:
296 			dev_err(&pdev->dev, "Unsupported ISEL setting: %d\n",
297 				pdata->isel);
298 			/* Fall through */
299 		case 200:
300 		case 0:
301 			wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
302 					WM831X_TCH_ISEL, 0);
303 			break;
304 		case 400:
305 			wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
306 					WM831X_TCH_ISEL, WM831X_TCH_ISEL);
307 			break;
308 		}
309 	}
310 
311 	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
312 			WM831X_TCH_PDONLY, 0);
313 
314 	/* Default to 96 samples/sec */
315 	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
316 			WM831X_TCH_RATE_MASK, 6);
317 
318 	if (pdata && pdata->data_irqf)
319 		irqf = pdata->data_irqf;
320 	else
321 		irqf = IRQF_TRIGGER_HIGH;
322 
323 	error = request_threaded_irq(wm831x_ts->data_irq,
324 				     NULL, wm831x_ts_data_irq,
325 				     irqf | IRQF_ONESHOT,
326 				     "Touchscreen data", wm831x_ts);
327 	if (error) {
328 		dev_err(&pdev->dev, "Failed to request data IRQ %d: %d\n",
329 			wm831x_ts->data_irq, error);
330 		goto err_alloc;
331 	}
332 	disable_irq(wm831x_ts->data_irq);
333 
334 	if (pdata && pdata->pd_irqf)
335 		irqf = pdata->pd_irqf;
336 	else
337 		irqf = IRQF_TRIGGER_HIGH;
338 
339 	error = request_threaded_irq(wm831x_ts->pd_irq,
340 				     NULL, wm831x_ts_pen_down_irq,
341 				     irqf | IRQF_ONESHOT,
342 				     "Touchscreen pen down", wm831x_ts);
343 	if (error) {
344 		dev_err(&pdev->dev, "Failed to request pen down IRQ %d: %d\n",
345 			wm831x_ts->pd_irq, error);
346 		goto err_data_irq;
347 	}
348 
349 	/* set up touch configuration */
350 	input_dev->name = "WM831x touchscreen";
351 	input_dev->phys = "wm831x";
352 	input_dev->open = wm831x_ts_input_open;
353 	input_dev->close = wm831x_ts_input_close;
354 
355 	__set_bit(EV_ABS, input_dev->evbit);
356 	__set_bit(EV_KEY, input_dev->evbit);
357 	__set_bit(BTN_TOUCH, input_dev->keybit);
358 
359 	input_set_abs_params(input_dev, ABS_X, 0, 4095, 5, 0);
360 	input_set_abs_params(input_dev, ABS_Y, 0, 4095, 5, 0);
361 	if (wm831x_ts->pressure)
362 		input_set_abs_params(input_dev, ABS_PRESSURE, 0, 4095, 5, 0);
363 
364 	input_set_drvdata(input_dev, wm831x_ts);
365 	input_dev->dev.parent = &pdev->dev;
366 
367 	error = input_register_device(input_dev);
368 	if (error)
369 		goto err_pd_irq;
370 
371 	platform_set_drvdata(pdev, wm831x_ts);
372 	return 0;
373 
374 err_pd_irq:
375 	free_irq(wm831x_ts->pd_irq, wm831x_ts);
376 err_data_irq:
377 	free_irq(wm831x_ts->data_irq, wm831x_ts);
378 err_alloc:
379 
380 	return error;
381 }
382 
383 static int wm831x_ts_remove(struct platform_device *pdev)
384 {
385 	struct wm831x_ts *wm831x_ts = platform_get_drvdata(pdev);
386 
387 	free_irq(wm831x_ts->pd_irq, wm831x_ts);
388 	free_irq(wm831x_ts->data_irq, wm831x_ts);
389 
390 	return 0;
391 }
392 
393 static struct platform_driver wm831x_ts_driver = {
394 	.driver = {
395 		.name = "wm831x-touch",
396 		.owner = THIS_MODULE,
397 	},
398 	.probe = wm831x_ts_probe,
399 	.remove = wm831x_ts_remove,
400 };
401 module_platform_driver(wm831x_ts_driver);
402 
403 /* Module information */
404 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
405 MODULE_DESCRIPTION("WM831x PMIC touchscreen driver");
406 MODULE_LICENSE("GPL");
407 MODULE_ALIAS("platform:wm831x-touch");
408