wm831x-ts.c revision e7cbb90ad244b9d3ba5c6d57aec05d6c73df0a98 
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};
72
73static irqreturn_t wm831x_ts_data_irq(int irq, void *irq_data)
74{
75	struct wm831x_ts *wm831x_ts = irq_data;
76	struct wm831x *wm831x = wm831x_ts->wm831x;
77	static int data_types[] = { ABS_X, ABS_Y, ABS_PRESSURE };
78	u16 data[3];
79	int count;
80	int i, ret;
81
82	if (wm831x_ts->pressure)
83		count = 3;
84	else
85		count = 2;
86
87	wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
88			WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
89
90	ret = wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count,
91			       data);
92	if (ret != 0) {
93		dev_err(wm831x->dev, "Failed to read touch data: %d\n",
94			ret);
95		return IRQ_NONE;
96	}
97
98	/*
99	 * We get a pen down reading on every reading, report pen up if any
100	 * individual reading does so.
101	 */
102	wm831x_ts->pen_down = true;
103	for (i = 0; i < count; i++) {
104		if (!(data[i] & WM831X_TCH_PD)) {
105			wm831x_ts->pen_down = false;
106			continue;
107		}
108		input_report_abs(wm831x_ts->input_dev, data_types[i],
109				 data[i] & WM831X_TCH_DATA_MASK);
110	}
111
112	if (!wm831x_ts->pen_down) {
113		disable_irq_nosync(wm831x_ts->data_irq);
114
115		/* Don't need data any more */
116		wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
117				WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
118				WM831X_TCH_Z_ENA, 0);
119
120		/* Flush any final samples that arrived while reading */
121		wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
122				WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
123
124		wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count, data);
125
126		if (wm831x_ts->pressure)
127			input_report_abs(wm831x_ts->input_dev,
128					 ABS_PRESSURE, 0);
129
130		input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 0);
131	}
132
133	input_sync(wm831x_ts->input_dev);
134
135	return IRQ_HANDLED;
136}
137
138static irqreturn_t wm831x_ts_pen_down_irq(int irq, void *irq_data)
139{
140	struct wm831x_ts *wm831x_ts = irq_data;
141	struct wm831x *wm831x = wm831x_ts->wm831x;
142	int ena = 0;
143
144	/* Start collecting data */
145	if (wm831x_ts->pressure)
146		ena |= WM831X_TCH_Z_ENA;
147
148	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
149			WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA,
150			WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | ena);
151
152	input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 1);
153	input_sync(wm831x_ts->input_dev);
154
155	wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
156			WM831X_TCHPD_EINT, WM831X_TCHPD_EINT);
157
158	wm831x_ts->pen_down = true;
159	enable_irq(wm831x_ts->data_irq);
160
161	return IRQ_HANDLED;
162}
163
164static int wm831x_ts_input_open(struct input_dev *idev)
165{
166	struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
167	struct wm831x *wm831x = wm831x_ts->wm831x;
168
169	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
170			WM831X_TCH_ENA | WM831X_TCH_CVT_ENA |
171			WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
172			WM831X_TCH_Z_ENA, WM831X_TCH_ENA);
173
174	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
175			WM831X_TCH_CVT_ENA, WM831X_TCH_CVT_ENA);
176
177	return 0;
178}
179
180static void wm831x_ts_input_close(struct input_dev *idev)
181{
182	struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
183	struct wm831x *wm831x = wm831x_ts->wm831x;
184
185	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
186			WM831X_TCH_ENA | WM831X_TCH_CVT_ENA |
187			WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
188			WM831X_TCH_Z_ENA, 0);
189
190	if (wm831x_ts->pen_down)
191		disable_irq(wm831x_ts->data_irq);
192}
193
194static __devinit int wm831x_ts_probe(struct platform_device *pdev)
195{
196	struct wm831x_ts *wm831x_ts;
197	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
198	struct wm831x_pdata *core_pdata = dev_get_platdata(pdev->dev.parent);
199	struct wm831x_touch_pdata *pdata = NULL;
200	struct input_dev *input_dev;
201	int error;
202
203	if (core_pdata)
204		pdata = core_pdata->touch;
205
206	wm831x_ts = kzalloc(sizeof(struct wm831x_ts), GFP_KERNEL);
207	input_dev = input_allocate_device();
208	if (!wm831x_ts || !input_dev) {
209		error = -ENOMEM;
210		goto err_alloc;
211	}
212
213	wm831x_ts->wm831x = wm831x;
214	wm831x_ts->input_dev = input_dev;
215
216	/*
217	 * If we have a direct IRQ use it, otherwise use the interrupt
218	 * from the WM831x IRQ controller.
219	 */
220	if (pdata && pdata->data_irq)
221		wm831x_ts->data_irq = pdata->data_irq;
222	else
223		wm831x_ts->data_irq = platform_get_irq_byname(pdev, "TCHDATA");
224
225	if (pdata && pdata->pd_irq)
226		wm831x_ts->pd_irq = pdata->pd_irq;
227	else
228		wm831x_ts->pd_irq = platform_get_irq_byname(pdev, "TCHPD");
229
230	if (pdata)
231		wm831x_ts->pressure = pdata->pressure;
232	else
233		wm831x_ts->pressure = true;
234
235	/* Five wire touchscreens can't report pressure */
236	if (pdata && pdata->fivewire) {
237		wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
238				WM831X_TCH_5WIRE, WM831X_TCH_5WIRE);
239
240		/* Pressure measurements are not possible for five wire mode */
241		WARN_ON(pdata->pressure && pdata->fivewire);
242		wm831x_ts->pressure = false;
243	} else {
244		wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
245				WM831X_TCH_5WIRE, 0);
246	}
247
248	if (pdata) {
249		switch (pdata->isel) {
250		default:
251			dev_err(&pdev->dev, "Unsupported ISEL setting: %d\n",
252				pdata->isel);
253			/* Fall through */
254		case 200:
255		case 0:
256			wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
257					WM831X_TCH_ISEL, 0);
258			break;
259		case 400:
260			wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
261					WM831X_TCH_ISEL, WM831X_TCH_ISEL);
262			break;
263		}
264	}
265
266	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
267			WM831X_TCH_PDONLY, 0);
268
269	/* Default to 96 samples/sec */
270	wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
271			WM831X_TCH_RATE_MASK, 6);
272
273	error = request_threaded_irq(wm831x_ts->data_irq,
274				     NULL, wm831x_ts_data_irq,
275				     IRQF_ONESHOT,
276				     "Touchscreen data", wm831x_ts);
277	if (error) {
278		dev_err(&pdev->dev, "Failed to request data IRQ %d: %d\n",
279			wm831x_ts->data_irq, error);
280		goto err_alloc;
281	}
282	disable_irq(wm831x_ts->data_irq);
283
284	error = request_threaded_irq(wm831x_ts->pd_irq,
285				     NULL, wm831x_ts_pen_down_irq,
286				     IRQF_ONESHOT,
287				     "Touchscreen pen down", wm831x_ts);
288	if (error) {
289		dev_err(&pdev->dev, "Failed to request pen down IRQ %d: %d\n",
290			wm831x_ts->pd_irq, error);
291		goto err_data_irq;
292	}
293
294	/* set up touch configuration */
295	input_dev->name = "WM831x touchscreen";
296	input_dev->phys = "wm831x";
297	input_dev->open = wm831x_ts_input_open;
298	input_dev->close = wm831x_ts_input_close;
299
300	__set_bit(EV_ABS, input_dev->evbit);
301	__set_bit(EV_KEY, input_dev->evbit);
302	__set_bit(BTN_TOUCH, input_dev->keybit);
303
304	input_set_abs_params(input_dev, ABS_X, 0, 4095, 5, 0);
305	input_set_abs_params(input_dev, ABS_Y, 0, 4095, 5, 0);
306	if (wm831x_ts->pressure)
307		input_set_abs_params(input_dev, ABS_PRESSURE, 0, 4095, 5, 0);
308
309	input_set_drvdata(input_dev, wm831x_ts);
310	input_dev->dev.parent = &pdev->dev;
311
312	error = input_register_device(input_dev);
313	if (error)
314		goto err_pd_irq;
315
316	platform_set_drvdata(pdev, wm831x_ts);
317	return 0;
318
319err_pd_irq:
320	free_irq(wm831x_ts->pd_irq, wm831x_ts);
321err_data_irq:
322	free_irq(wm831x_ts->data_irq, wm831x_ts);
323err_alloc:
324	input_free_device(input_dev);
325	kfree(wm831x_ts);
326
327	return error;
328}
329
330static __devexit int wm831x_ts_remove(struct platform_device *pdev)
331{
332	struct wm831x_ts *wm831x_ts = platform_get_drvdata(pdev);
333
334	free_irq(wm831x_ts->pd_irq, wm831x_ts);
335	free_irq(wm831x_ts->data_irq, wm831x_ts);
336	input_unregister_device(wm831x_ts->input_dev);
337	kfree(wm831x_ts);
338
339	platform_set_drvdata(pdev, NULL);
340	return 0;
341}
342
343static struct platform_driver wm831x_ts_driver = {
344	.driver = {
345		.name = "wm831x-touch",
346		.owner = THIS_MODULE,
347	},
348	.probe = wm831x_ts_probe,
349	.remove = __devexit_p(wm831x_ts_remove),
350};
351
352static int __init wm831x_ts_init(void)
353{
354	return platform_driver_register(&wm831x_ts_driver);
355}
356module_init(wm831x_ts_init);
357
358static void __exit wm831x_ts_exit(void)
359{
360	platform_driver_unregister(&wm831x_ts_driver);
361}
362module_exit(wm831x_ts_exit);
363
364/* Module information */
365MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
366MODULE_DESCRIPTION("WM831x PMIC touchscreen driver");
367MODULE_LICENSE("GPL");
368MODULE_ALIAS("platform:wm831x-touch");
369