summaryrefslogtreecommitdiff
path: root/drivers/input/touchscreen/lpc32xx_ts.c
blob: b51450b3d943a24cc46485440ef0d03a7e2b4fd9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * LPC32xx built-in touchscreen driver
 *
 * Copyright (C) 2010 NXP Semiconductors
 */

#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/of.h>

/*
 * Touchscreen controller register offsets
 */
#define LPC32XX_TSC_STAT			0x00
#define LPC32XX_TSC_SEL				0x04
#define LPC32XX_TSC_CON				0x08
#define LPC32XX_TSC_FIFO			0x0C
#define LPC32XX_TSC_DTR				0x10
#define LPC32XX_TSC_RTR				0x14
#define LPC32XX_TSC_UTR				0x18
#define LPC32XX_TSC_TTR				0x1C
#define LPC32XX_TSC_DXP				0x20
#define LPC32XX_TSC_MIN_X			0x24
#define LPC32XX_TSC_MAX_X			0x28
#define LPC32XX_TSC_MIN_Y			0x2C
#define LPC32XX_TSC_MAX_Y			0x30
#define LPC32XX_TSC_AUX_UTR			0x34
#define LPC32XX_TSC_AUX_MIN			0x38
#define LPC32XX_TSC_AUX_MAX			0x3C

#define LPC32XX_TSC_STAT_FIFO_OVRRN		(1 << 8)
#define LPC32XX_TSC_STAT_FIFO_EMPTY		(1 << 7)

#define LPC32XX_TSC_SEL_DEFVAL			0x0284

#define LPC32XX_TSC_ADCCON_IRQ_TO_FIFO_4	(0x1 << 11)
#define LPC32XX_TSC_ADCCON_X_SAMPLE_SIZE(s)	((10 - (s)) << 7)
#define LPC32XX_TSC_ADCCON_Y_SAMPLE_SIZE(s)	((10 - (s)) << 4)
#define LPC32XX_TSC_ADCCON_POWER_UP		(1 << 2)
#define LPC32XX_TSC_ADCCON_AUTO_EN		(1 << 0)

#define LPC32XX_TSC_FIFO_TS_P_LEVEL		(1 << 31)
#define LPC32XX_TSC_FIFO_NORMALIZE_X_VAL(x)	(((x) & 0x03FF0000) >> 16)
#define LPC32XX_TSC_FIFO_NORMALIZE_Y_VAL(y)	((y) & 0x000003FF)

#define LPC32XX_TSC_ADCDAT_VALUE_MASK		0x000003FF

#define LPC32XX_TSC_MIN_XY_VAL			0x0
#define LPC32XX_TSC_MAX_XY_VAL			0x3FF

#define MOD_NAME "ts-lpc32xx"

#define tsc_readl(dev, reg) \
	__raw_readl((dev)->tsc_base + (reg))
#define tsc_writel(dev, reg, val) \
	__raw_writel((val), (dev)->tsc_base + (reg))

struct lpc32xx_tsc {
	struct input_dev *dev;
	void __iomem *tsc_base;
	int irq;
	struct clk *clk;
};

static void lpc32xx_fifo_clear(struct lpc32xx_tsc *tsc)
{
	while (!(tsc_readl(tsc, LPC32XX_TSC_STAT) &
			LPC32XX_TSC_STAT_FIFO_EMPTY))
		tsc_readl(tsc, LPC32XX_TSC_FIFO);
}

static irqreturn_t lpc32xx_ts_interrupt(int irq, void *dev_id)
{
	u32 tmp, rv[4], xs[4], ys[4];
	int idx;
	struct lpc32xx_tsc *tsc = dev_id;
	struct input_dev *input = tsc->dev;

	tmp = tsc_readl(tsc, LPC32XX_TSC_STAT);

	if (tmp & LPC32XX_TSC_STAT_FIFO_OVRRN) {
		/* FIFO overflow - throw away samples */
		lpc32xx_fifo_clear(tsc);
		return IRQ_HANDLED;
	}

	/*
	 * Gather and normalize 4 samples. Pen-up events may have less
	 * than 4 samples, but its ok to pop 4 and let the last sample
	 * pen status check drop the samples.
	 */
	idx = 0;
	while (idx < 4 &&
	       !(tsc_readl(tsc, LPC32XX_TSC_STAT) &
			LPC32XX_TSC_STAT_FIFO_EMPTY)) {
		tmp = tsc_readl(tsc, LPC32XX_TSC_FIFO);
		xs[idx] = LPC32XX_TSC_ADCDAT_VALUE_MASK -
			LPC32XX_TSC_FIFO_NORMALIZE_X_VAL(tmp);
		ys[idx] = LPC32XX_TSC_ADCDAT_VALUE_MASK -
			LPC32XX_TSC_FIFO_NORMALIZE_Y_VAL(tmp);
		rv[idx] = tmp;
		idx++;
	}

	/* Data is only valid if pen is still down in last sample */
	if (!(rv[3] & LPC32XX_TSC_FIFO_TS_P_LEVEL) && idx == 4) {
		/* Use average of 2nd and 3rd sample for position */
		input_report_abs(input, ABS_X, (xs[1] + xs[2]) / 2);
		input_report_abs(input, ABS_Y, (ys[1] + ys[2]) / 2);
		input_report_key(input, BTN_TOUCH, 1);
	} else {
		input_report_key(input, BTN_TOUCH, 0);
	}

	input_sync(input);

	return IRQ_HANDLED;
}

static void lpc32xx_stop_tsc(struct lpc32xx_tsc *tsc)
{
	/* Disable auto mode */
	tsc_writel(tsc, LPC32XX_TSC_CON,
		   tsc_readl(tsc, LPC32XX_TSC_CON) &
			     ~LPC32XX_TSC_ADCCON_AUTO_EN);

	clk_disable_unprepare(tsc->clk);
}

static int lpc32xx_setup_tsc(struct lpc32xx_tsc *tsc)
{
	u32 tmp;
	int err;

	err = clk_prepare_enable(tsc->clk);
	if (err)
		return err;

	tmp = tsc_readl(tsc, LPC32XX_TSC_CON) & ~LPC32XX_TSC_ADCCON_POWER_UP;

	/* Set the TSC FIFO depth to 4 samples @ 10-bits per sample (max) */
	tmp = LPC32XX_TSC_ADCCON_IRQ_TO_FIFO_4 |
	      LPC32XX_TSC_ADCCON_X_SAMPLE_SIZE(10) |
	      LPC32XX_TSC_ADCCON_Y_SAMPLE_SIZE(10);
	tsc_writel(tsc, LPC32XX_TSC_CON, tmp);

	/* These values are all preset */
	tsc_writel(tsc, LPC32XX_TSC_SEL, LPC32XX_TSC_SEL_DEFVAL);
	tsc_writel(tsc, LPC32XX_TSC_MIN_X, LPC32XX_TSC_MIN_XY_VAL);
	tsc_writel(tsc, LPC32XX_TSC_MAX_X, LPC32XX_TSC_MAX_XY_VAL);
	tsc_writel(tsc, LPC32XX_TSC_MIN_Y, LPC32XX_TSC_MIN_XY_VAL);
	tsc_writel(tsc, LPC32XX_TSC_MAX_Y, LPC32XX_TSC_MAX_XY_VAL);

	/* Aux support is not used */
	tsc_writel(tsc, LPC32XX_TSC_AUX_UTR, 0);
	tsc_writel(tsc, LPC32XX_TSC_AUX_MIN, 0);
	tsc_writel(tsc, LPC32XX_TSC_AUX_MAX, 0);

	/*
	 * Set sample rate to about 240Hz per X/Y pair. A single measurement
	 * consists of 4 pairs which gives about a 60Hz sample rate based on
	 * a stable 32768Hz clock source. Values are in clocks.
	 * Rate is (32768 / (RTR + XCONV + RTR + YCONV + DXP + TTR + UTR) / 4
	 */
	tsc_writel(tsc, LPC32XX_TSC_RTR, 0x2);
	tsc_writel(tsc, LPC32XX_TSC_DTR, 0x2);
	tsc_writel(tsc, LPC32XX_TSC_TTR, 0x10);
	tsc_writel(tsc, LPC32XX_TSC_DXP, 0x4);
	tsc_writel(tsc, LPC32XX_TSC_UTR, 88);

	lpc32xx_fifo_clear(tsc);

	/* Enable automatic ts event capture */
	tsc_writel(tsc, LPC32XX_TSC_CON, tmp | LPC32XX_TSC_ADCCON_AUTO_EN);

	return 0;
}

static int lpc32xx_ts_open(struct input_dev *dev)
{
	struct lpc32xx_tsc *tsc = input_get_drvdata(dev);

	return lpc32xx_setup_tsc(tsc);
}

static void lpc32xx_ts_close(struct input_dev *dev)
{
	struct lpc32xx_tsc *tsc = input_get_drvdata(dev);

	lpc32xx_stop_tsc(tsc);
}

static int lpc32xx_ts_probe(struct platform_device *pdev)
{
	struct lpc32xx_tsc *tsc;
	struct input_dev *input;
	struct resource *res;
	resource_size_t size;
	int irq;
	int error;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		dev_err(&pdev->dev, "Can't get memory resource\n");
		return -ENOENT;
	}

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return irq;

	tsc = kzalloc(sizeof(*tsc), GFP_KERNEL);
	input = input_allocate_device();
	if (!tsc || !input) {
		dev_err(&pdev->dev, "failed allocating memory\n");
		error = -ENOMEM;
		goto err_free_mem;
	}

	tsc->dev = input;
	tsc->irq = irq;

	size = resource_size(res);

	if (!request_mem_region(res->start, size, pdev->name)) {
		dev_err(&pdev->dev, "TSC registers are not free\n");
		error = -EBUSY;
		goto err_free_mem;
	}

	tsc->tsc_base = ioremap(res->start, size);
	if (!tsc->tsc_base) {
		dev_err(&pdev->dev, "Can't map memory\n");
		error = -ENOMEM;
		goto err_release_mem;
	}

	tsc->clk = clk_get(&pdev->dev, NULL);
	if (IS_ERR(tsc->clk)) {
		dev_err(&pdev->dev, "failed getting clock\n");
		error = PTR_ERR(tsc->clk);
		goto err_unmap;
	}

	input->name = MOD_NAME;
	input->phys = "lpc32xx/input0";
	input->id.bustype = BUS_HOST;
	input->id.vendor = 0x0001;
	input->id.product = 0x0002;
	input->id.version = 0x0100;
	input->dev.parent = &pdev->dev;
	input->open = lpc32xx_ts_open;
	input->close = lpc32xx_ts_close;

	input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
	input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
	input_set_abs_params(input, ABS_X, LPC32XX_TSC_MIN_XY_VAL,
			     LPC32XX_TSC_MAX_XY_VAL, 0, 0);
	input_set_abs_params(input, ABS_Y, LPC32XX_TSC_MIN_XY_VAL,
			     LPC32XX_TSC_MAX_XY_VAL, 0, 0);

	input_set_drvdata(input, tsc);

	error = request_irq(tsc->irq, lpc32xx_ts_interrupt,
			    0, pdev->name, tsc);
	if (error) {
		dev_err(&pdev->dev, "failed requesting interrupt\n");
		goto err_put_clock;
	}

	error = input_register_device(input);
	if (error) {
		dev_err(&pdev->dev, "failed registering input device\n");
		goto err_free_irq;
	}

	platform_set_drvdata(pdev, tsc);
	device_init_wakeup(&pdev->dev, 1);

	return 0;

err_free_irq:
	free_irq(tsc->irq, tsc);
err_put_clock:
	clk_put(tsc->clk);
err_unmap:
	iounmap(tsc->tsc_base);
err_release_mem:
	release_mem_region(res->start, size);
err_free_mem:
	input_free_device(input);
	kfree(tsc);

	return error;
}

static int lpc32xx_ts_remove(struct platform_device *pdev)
{
	struct lpc32xx_tsc *tsc = platform_get_drvdata(pdev);
	struct resource *res;

	free_irq(tsc->irq, tsc);

	input_unregister_device(tsc->dev);

	clk_put(tsc->clk);

	iounmap(tsc->tsc_base);
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	release_mem_region(res->start, resource_size(res));

	kfree(tsc);

	return 0;
}

#ifdef CONFIG_PM
static int lpc32xx_ts_suspend(struct device *dev)
{
	struct lpc32xx_tsc *tsc = dev_get_drvdata(dev);
	struct input_dev *input = tsc->dev;

	/*
	 * Suspend and resume can be called when the device hasn't been
	 * enabled. If there are no users that have the device open, then
	 * avoid calling the TSC stop and start functions as the TSC
	 * isn't yet clocked.
	 */
	mutex_lock(&input->mutex);

	if (input_device_enabled(input)) {
		if (device_may_wakeup(dev))
			enable_irq_wake(tsc->irq);
		else
			lpc32xx_stop_tsc(tsc);
	}

	mutex_unlock(&input->mutex);

	return 0;
}

static int lpc32xx_ts_resume(struct device *dev)
{
	struct lpc32xx_tsc *tsc = dev_get_drvdata(dev);
	struct input_dev *input = tsc->dev;

	mutex_lock(&input->mutex);

	if (input_device_enabled(input)) {
		if (device_may_wakeup(dev))
			disable_irq_wake(tsc->irq);
		else
			lpc32xx_setup_tsc(tsc);
	}

	mutex_unlock(&input->mutex);

	return 0;
}

static const struct dev_pm_ops lpc32xx_ts_pm_ops = {
	.suspend	= lpc32xx_ts_suspend,
	.resume		= lpc32xx_ts_resume,
};
#define LPC32XX_TS_PM_OPS (&lpc32xx_ts_pm_ops)
#else
#define LPC32XX_TS_PM_OPS NULL
#endif

#ifdef CONFIG_OF
static const struct of_device_id lpc32xx_tsc_of_match[] = {
	{ .compatible = "nxp,lpc3220-tsc", },
	{ },
};
MODULE_DEVICE_TABLE(of, lpc32xx_tsc_of_match);
#endif

static struct platform_driver lpc32xx_ts_driver = {
	.probe		= lpc32xx_ts_probe,
	.remove		= lpc32xx_ts_remove,
	.driver		= {
		.name	= MOD_NAME,
		.pm	= LPC32XX_TS_PM_OPS,
		.of_match_table = of_match_ptr(lpc32xx_tsc_of_match),
	},
};
module_platform_driver(lpc32xx_ts_driver);

MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com");
MODULE_DESCRIPTION("LPC32XX TSC Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:lpc32xx_ts");