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/drivers/input/touchscreen/tps6507x-ts.c

https://bitbucket.org/ndreys/linux-sunxi
C | 390 lines | 287 code | 73 blank | 30 comment | 31 complexity | 2f359191a9a6668c7beb3354d23eb025 MD5 | raw file
Possible License(s): GPL-2.0, LGPL-2.0, AGPL-1.0
  1/*
  2 * drivers/input/touchscreen/tps6507x_ts.c
  3 *
  4 * Touchscreen driver for the tps6507x chip.
  5 *
  6 * Copyright (c) 2009 RidgeRun (todd.fischer@ridgerun.com)
  7 *
  8 * Credits:
  9 *
 10 *    Using code from tsc2007, MtekVision Co., Ltd.
 11 *
 12 * For licencing details see kernel-base/COPYING
 13 *
 14 * TPS65070, TPS65073, TPS650731, and TPS650732 support
 15 * 10 bit touch screen interface.
 16 */
 17
 18#include <linux/module.h>
 19#include <linux/workqueue.h>
 20#include <linux/slab.h>
 21#include <linux/input.h>
 22#include <linux/platform_device.h>
 23#include <linux/mfd/tps6507x.h>
 24#include <linux/input/tps6507x-ts.h>
 25#include <linux/delay.h>
 26
 27#define TSC_DEFAULT_POLL_PERIOD 30 /* ms */
 28#define TPS_DEFAULT_MIN_PRESSURE 0x30
 29#define MAX_10BIT ((1 << 10) - 1)
 30
 31#define	TPS6507X_ADCONFIG_CONVERT_TS (TPS6507X_ADCONFIG_AD_ENABLE | \
 32					 TPS6507X_ADCONFIG_START_CONVERSION | \
 33					 TPS6507X_ADCONFIG_INPUT_REAL_TSC)
 34#define	TPS6507X_ADCONFIG_POWER_DOWN_TS (TPS6507X_ADCONFIG_INPUT_REAL_TSC)
 35
 36struct ts_event {
 37	u16	x;
 38	u16	y;
 39	u16	pressure;
 40};
 41
 42struct tps6507x_ts {
 43	struct input_dev	*input_dev;
 44	struct device		*dev;
 45	char			phys[32];
 46	struct delayed_work	work;
 47	unsigned		polling;	/* polling is active */
 48	struct ts_event		tc;
 49	struct tps6507x_dev	*mfd;
 50	u16			model;
 51	unsigned		pendown;
 52	int			irq;
 53	void			(*clear_penirq)(void);
 54	unsigned long		poll_period;	/* ms */
 55	u16			min_pressure;
 56	int			vref;		/* non-zero to leave vref on */
 57};
 58
 59static int tps6507x_read_u8(struct tps6507x_ts *tsc, u8 reg, u8 *data)
 60{
 61	int err;
 62
 63	err = tsc->mfd->read_dev(tsc->mfd, reg, 1, data);
 64
 65	if (err)
 66		return err;
 67
 68	return 0;
 69}
 70
 71static int tps6507x_write_u8(struct tps6507x_ts *tsc, u8 reg, u8 data)
 72{
 73	return tsc->mfd->write_dev(tsc->mfd, reg, 1, &data);
 74}
 75
 76static s32 tps6507x_adc_conversion(struct tps6507x_ts *tsc,
 77				   u8 tsc_mode, u16 *value)
 78{
 79	s32 ret;
 80	u8 adc_status;
 81	u8 result;
 82
 83	/* Route input signal to A/D converter */
 84
 85	ret = tps6507x_write_u8(tsc, TPS6507X_REG_TSCMODE, tsc_mode);
 86	if (ret) {
 87		dev_err(tsc->dev, "TSC mode read failed\n");
 88		goto err;
 89	}
 90
 91	/* Start A/D conversion */
 92
 93	ret = tps6507x_write_u8(tsc, TPS6507X_REG_ADCONFIG,
 94				TPS6507X_ADCONFIG_CONVERT_TS);
 95	if (ret) {
 96		dev_err(tsc->dev, "ADC config write failed\n");
 97		return ret;
 98	}
 99
100	do {
101		ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADCONFIG,
102				       &adc_status);
103		if (ret) {
104			dev_err(tsc->dev, "ADC config read failed\n");
105			goto err;
106		}
107	} while (adc_status & TPS6507X_ADCONFIG_START_CONVERSION);
108
109	ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADRESULT_2, &result);
110	if (ret) {
111		dev_err(tsc->dev, "ADC result 2 read failed\n");
112		goto err;
113	}
114
115	*value = (result & TPS6507X_REG_ADRESULT_2_MASK) << 8;
116
117	ret = tps6507x_read_u8(tsc, TPS6507X_REG_ADRESULT_1, &result);
118	if (ret) {
119		dev_err(tsc->dev, "ADC result 1 read failed\n");
120		goto err;
121	}
122
123	*value |= result;
124
125	dev_dbg(tsc->dev, "TSC channel %d = 0x%X\n", tsc_mode, *value);
126
127err:
128	return ret;
129}
130
131/* Need to call tps6507x_adc_standby() after using A/D converter for the
132 * touch screen interrupt to work properly.
133 */
134
135static s32 tps6507x_adc_standby(struct tps6507x_ts *tsc)
136{
137	s32 ret;
138	s32 loops = 0;
139	u8 val;
140
141	ret = tps6507x_write_u8(tsc,  TPS6507X_REG_ADCONFIG,
142				TPS6507X_ADCONFIG_INPUT_TSC);
143	if (ret)
144		return ret;
145
146	ret = tps6507x_write_u8(tsc, TPS6507X_REG_TSCMODE,
147				TPS6507X_TSCMODE_STANDBY);
148	if (ret)
149		return ret;
150
151	ret = tps6507x_read_u8(tsc, TPS6507X_REG_INT, &val);
152	if (ret)
153		return ret;
154
155	while (val & TPS6507X_REG_TSC_INT) {
156		mdelay(10);
157		ret = tps6507x_read_u8(tsc, TPS6507X_REG_INT, &val);
158		if (ret)
159			return ret;
160		loops++;
161	}
162
163	return ret;
164}
165
166static void tps6507x_ts_handler(struct work_struct *work)
167{
168	struct tps6507x_ts *tsc =  container_of(work,
169				struct tps6507x_ts, work.work);
170	struct input_dev *input_dev = tsc->input_dev;
171	int pendown;
172	int schd;
173	int poll = 0;
174	s32 ret;
175
176	ret =  tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_PRESSURE,
177				       &tsc->tc.pressure);
178	if (ret)
179		goto done;
180
181	pendown = tsc->tc.pressure > tsc->min_pressure;
182
183	if (unlikely(!pendown && tsc->pendown)) {
184		dev_dbg(tsc->dev, "UP\n");
185		input_report_key(input_dev, BTN_TOUCH, 0);
186		input_report_abs(input_dev, ABS_PRESSURE, 0);
187		input_sync(input_dev);
188		tsc->pendown = 0;
189	}
190
191	if (pendown) {
192
193		if (!tsc->pendown) {
194			dev_dbg(tsc->dev, "DOWN\n");
195			input_report_key(input_dev, BTN_TOUCH, 1);
196		} else
197			dev_dbg(tsc->dev, "still down\n");
198
199		ret =  tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_X_POSITION,
200					       &tsc->tc.x);
201		if (ret)
202			goto done;
203
204		ret =  tps6507x_adc_conversion(tsc, TPS6507X_TSCMODE_Y_POSITION,
205					       &tsc->tc.y);
206		if (ret)
207			goto done;
208
209		input_report_abs(input_dev, ABS_X, tsc->tc.x);
210		input_report_abs(input_dev, ABS_Y, tsc->tc.y);
211		input_report_abs(input_dev, ABS_PRESSURE, tsc->tc.pressure);
212		input_sync(input_dev);
213		tsc->pendown = 1;
214		poll = 1;
215	}
216
217done:
218	/* always poll if not using interrupts */
219	poll = 1;
220
221	if (poll) {
222		schd = schedule_delayed_work(&tsc->work,
223					msecs_to_jiffies(tsc->poll_period));
224		if (schd)
225			tsc->polling = 1;
226		else {
227			tsc->polling = 0;
228			dev_err(tsc->dev, "re-schedule failed");
229		}
230	} else
231		tsc->polling = 0;
232
233	ret = tps6507x_adc_standby(tsc);
234}
235
236static int tps6507x_ts_probe(struct platform_device *pdev)
237{
238	int error;
239	struct tps6507x_ts *tsc;
240	struct tps6507x_dev *tps6507x_dev = dev_get_drvdata(pdev->dev.parent);
241	struct touchscreen_init_data *init_data;
242	struct input_dev *input_dev;
243	struct tps6507x_board *tps_board;
244	int schd;
245
246	/**
247	 * tps_board points to pmic related constants
248	 * coming from the board-evm file.
249	 */
250
251	tps_board = (struct tps6507x_board *)tps6507x_dev->dev->platform_data;
252
253	if (!tps_board) {
254		dev_err(tps6507x_dev->dev,
255			"Could not find tps6507x platform data\n");
256		return -EIO;
257	}
258
259	/**
260	 * init_data points to array of regulator_init structures
261	 * coming from the board-evm file.
262	 */
263
264	init_data = tps_board->tps6507x_ts_init_data;
265
266	tsc = kzalloc(sizeof(struct tps6507x_ts), GFP_KERNEL);
267	if (!tsc) {
268		dev_err(tps6507x_dev->dev, "failed to allocate driver data\n");
269		error = -ENOMEM;
270		goto err0;
271	}
272
273	tps6507x_dev->ts = tsc;
274	tsc->mfd = tps6507x_dev;
275	tsc->dev = tps6507x_dev->dev;
276	input_dev = input_allocate_device();
277	if (!input_dev) {
278		dev_err(tsc->dev, "Failed to allocate input device.\n");
279		error = -ENOMEM;
280		goto err1;
281	}
282
283	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
284	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
285
286	input_set_abs_params(input_dev, ABS_X, 0, MAX_10BIT, 0, 0);
287	input_set_abs_params(input_dev, ABS_Y, 0, MAX_10BIT, 0, 0);
288	input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_10BIT, 0, 0);
289
290	input_dev->name = "TPS6507x Touchscreen";
291	input_dev->id.bustype = BUS_I2C;
292	input_dev->dev.parent = tsc->dev;
293
294	snprintf(tsc->phys, sizeof(tsc->phys),
295		 "%s/input0", dev_name(tsc->dev));
296	input_dev->phys = tsc->phys;
297
298	dev_dbg(tsc->dev, "device: %s\n", input_dev->phys);
299
300	input_set_drvdata(input_dev, tsc);
301
302	tsc->input_dev = input_dev;
303
304	INIT_DELAYED_WORK(&tsc->work, tps6507x_ts_handler);
305
306	if (init_data) {
307		tsc->poll_period = init_data->poll_period;
308		tsc->vref = init_data->vref;
309		tsc->min_pressure = init_data->min_pressure;
310		input_dev->id.vendor = init_data->vendor;
311		input_dev->id.product = init_data->product;
312		input_dev->id.version = init_data->version;
313	} else {
314		tsc->poll_period = TSC_DEFAULT_POLL_PERIOD;
315		tsc->min_pressure = TPS_DEFAULT_MIN_PRESSURE;
316	}
317
318	error = tps6507x_adc_standby(tsc);
319	if (error)
320		goto err2;
321
322	error = input_register_device(input_dev);
323	if (error)
324		goto err2;
325
326	schd = schedule_delayed_work(&tsc->work,
327				     msecs_to_jiffies(tsc->poll_period));
328
329	if (schd)
330		tsc->polling = 1;
331	else {
332		tsc->polling = 0;
333		dev_err(tsc->dev, "schedule failed");
334		goto err2;
335	 }
336	platform_set_drvdata(pdev, tps6507x_dev);
337
338	return 0;
339
340err2:
341	cancel_delayed_work_sync(&tsc->work);
342	input_free_device(input_dev);
343err1:
344	kfree(tsc);
345	tps6507x_dev->ts = NULL;
346err0:
347	return error;
348}
349
350static int __devexit tps6507x_ts_remove(struct platform_device *pdev)
351{
352	struct tps6507x_dev *tps6507x_dev = platform_get_drvdata(pdev);
353	struct tps6507x_ts *tsc = tps6507x_dev->ts;
354	struct input_dev *input_dev = tsc->input_dev;
355
356	cancel_delayed_work_sync(&tsc->work);
357
358	input_unregister_device(input_dev);
359
360	tps6507x_dev->ts = NULL;
361	kfree(tsc);
362
363	return 0;
364}
365
366static struct platform_driver tps6507x_ts_driver = {
367	.driver = {
368		.name = "tps6507x-ts",
369		.owner = THIS_MODULE,
370	},
371	.probe = tps6507x_ts_probe,
372	.remove = __devexit_p(tps6507x_ts_remove),
373};
374
375static int __init tps6507x_ts_init(void)
376{
377	return platform_driver_register(&tps6507x_ts_driver);
378}
379module_init(tps6507x_ts_init);
380
381static void __exit tps6507x_ts_exit(void)
382{
383	platform_driver_unregister(&tps6507x_ts_driver);
384}
385module_exit(tps6507x_ts_exit);
386
387MODULE_AUTHOR("Todd Fischer <todd.fischer@ridgerun.com>");
388MODULE_DESCRIPTION("TPS6507x - TouchScreen driver");
389MODULE_LICENSE("GPL v2");
390MODULE_ALIAS("platform:tps6507x-tsc");