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
64struct 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
74static 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
88static 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
160static 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
191static 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
207static 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_sync(&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
236static __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	if (pdata && pdata->data_irq)
264		wm831x_ts->data_irq = pdata->data_irq;
265	else
266		wm831x_ts->data_irq = platform_get_irq_byname(pdev, "TCHDATA");
267
268	if (pdata && pdata->pd_irq)
269		wm831x_ts->pd_irq = pdata->pd_irq;
270	else
271		wm831x_ts->pd_irq = platform_get_irq_byname(pdev, "TCHPD");
272
273	if (pdata)
274		wm831x_ts->pressure = pdata->pressure;
275	else
276		wm831x_ts->pressure = true;
277
278	/* Five wire touchscreens can't report pressure */
279	if (pdata && pdata->fivewire) {
280		wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
281				WM831X_TCH_5WIRE, WM831X_TCH_5WIRE);
282
283		/* Pressure measurements are not possible for five wire mode */
284		WARN_ON(pdata->pressure && pdata->fivewire);
285		wm831x_ts->pressure = false;
286	} else {
287		wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
288				WM831X_TCH_5WIRE, 0);
289	}
290
291	if (pdata) {
292		switch (pdata->isel) {
293		default:
294			dev_err(&pdev->dev, "Unsupported ISEL setting: %d\n",
295				pdata->isel);
296			/* Fall through */
297		case 200:
298		case 0:
299			wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
300					WM831X_TCH_ISEL, 0);
301			break;
302		case 400:
303			wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
304					WM831X_TCH_ISEL, WM831X_TCH_ISEL);
305			break;
306		}
307	}
308
309	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
310			WM831X_TCH_PDONLY, 0);
311
312	/* Default to 96 samples/sec */
313	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
314			WM831X_TCH_RATE_MASK, 6);
315
316	if (pdata && pdata->data_irqf)
317		irqf = pdata->data_irqf;
318	else
319		irqf = IRQF_TRIGGER_HIGH;
320
321	error = request_threaded_irq(wm831x_ts->data_irq,
322				     NULL, wm831x_ts_data_irq,
323				     irqf | IRQF_ONESHOT,
324				     "Touchscreen data", wm831x_ts);
325	if (error) {
326		dev_err(&pdev->dev, "Failed to request data IRQ %d: %d\n",
327			wm831x_ts->data_irq, error);
328		goto err_alloc;
329	}
330	disable_irq(wm831x_ts->data_irq);
331
332	if (pdata && pdata->pd_irqf)
333		irqf = pdata->pd_irqf;
334	else
335		irqf = IRQF_TRIGGER_HIGH;
336
337	error = request_threaded_irq(wm831x_ts->pd_irq,
338				     NULL, wm831x_ts_pen_down_irq,
339				     irqf | IRQF_ONESHOT,
340				     "Touchscreen pen down", wm831x_ts);
341	if (error) {
342		dev_err(&pdev->dev, "Failed to request pen down IRQ %d: %d\n",
343			wm831x_ts->pd_irq, error);
344		goto err_data_irq;
345	}
346
347	/* set up touch configuration */
348	input_dev->name = "WM831x touchscreen";
349	input_dev->phys = "wm831x";
350	input_dev->open = wm831x_ts_input_open;
351	input_dev->close = wm831x_ts_input_close;
352
353	__set_bit(EV_ABS, input_dev->evbit);
354	__set_bit(EV_KEY, input_dev->evbit);
355	__set_bit(BTN_TOUCH, input_dev->keybit);
356
357	input_set_abs_params(input_dev, ABS_X, 0, 4095, 5, 0);
358	input_set_abs_params(input_dev, ABS_Y, 0, 4095, 5, 0);
359	if (wm831x_ts->pressure)
360		input_set_abs_params(input_dev, ABS_PRESSURE, 0, 4095, 5, 0);
361
362	input_set_drvdata(input_dev, wm831x_ts);
363	input_dev->dev.parent = &pdev->dev;
364
365	error = input_register_device(input_dev);
366	if (error)
367		goto err_pd_irq;
368
369	platform_set_drvdata(pdev, wm831x_ts);
370	return 0;
371
372err_pd_irq:
373	free_irq(wm831x_ts->pd_irq, wm831x_ts);
374err_data_irq:
375	free_irq(wm831x_ts->data_irq, wm831x_ts);
376err_alloc:
377	input_free_device(input_dev);
378	kfree(wm831x_ts);
379
380	return error;
381}
382
383static __devexit 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	input_unregister_device(wm831x_ts->input_dev);
390	kfree(wm831x_ts);
391
392	platform_set_drvdata(pdev, NULL);
393	return 0;
394}
395
396static struct platform_driver wm831x_ts_driver = {
397	.driver = {
398		.name = "wm831x-touch",
399		.owner = THIS_MODULE,
400	},
401	.probe = wm831x_ts_probe,
402	.remove = __devexit_p(wm831x_ts_remove),
403};
404module_platform_driver(wm831x_ts_driver);
405
406/* Module information */
407MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
408MODULE_DESCRIPTION("WM831x PMIC touchscreen driver");
409MODULE_LICENSE("GPL");
410MODULE_ALIAS("platform:wm831x-touch");
411