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
63struct 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
73static 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
87static 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
159static 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
190static 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
206static 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
235static 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
373err_pd_irq:
374	free_irq(wm831x_ts->pd_irq, wm831x_ts);
375err_data_irq:
376	free_irq(wm831x_ts->data_irq, wm831x_ts);
377err_alloc:
378
379	return error;
380}
381
382static 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
392static struct platform_driver wm831x_ts_driver = {
393	.driver = {
394		.name = "wm831x-touch",
395		.owner = THIS_MODULE,
396	},
397	.probe = wm831x_ts_probe,
398	.remove = wm831x_ts_remove,
399};
400module_platform_driver(wm831x_ts_driver);
401
402/* Module information */
403MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
404MODULE_DESCRIPTION("WM831x PMIC touchscreen driver");
405MODULE_LICENSE("GPL");
406MODULE_ALIAS("platform:wm831x-touch");
407