summaryrefslogtreecommitdiffstats
path: root/drivers/input/touchscreen/atmel_tsadcc.c
blob: 9c7fce4d74d09b3f6ec1927e87ad659a6fc8a910 (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
/*
 *  Atmel Touch Screen Driver
 *
 *  Copyright (c) 2008 ATMEL
 *  Copyright (c) 2008 Dan Liang
 *  Copyright (c) 2008 TimeSys Corporation
 *  Copyright (c) 2008 Justin Waters
 *
 *  Based on touchscreen code from Atmel Corporation.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 */
#include <linux/init.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/input.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/clk.h>
#include <linux/platform_device.h>
#include <linux/io.h>

/* Register definitions based on AT91SAM9RL64 preliminary draft datasheet */

#define ATMEL_TSADCC_CR		0x00	/* Control register */
#define   ATMEL_TSADCC_SWRST	(1 << 0)	/* Software Reset*/
#define	  ATMEL_TSADCC_START	(1 << 1)	/* Start conversion */

#define ATMEL_TSADCC_MR		0x04	/* Mode register */
#define	  ATMEL_TSADCC_TSAMOD	(3    <<  0)	/* ADC mode */
#define	    ATMEL_TSADCC_TSAMOD_ADC_ONLY_MODE	(0x0)	/* ADC Mode */
#define	    ATMEL_TSADCC_TSAMOD_TS_ONLY_MODE	(0x1)	/* Touch Screen Only Mode */
#define	  ATMEL_TSADCC_LOWRES	(1    <<  4)	/* Resolution selection */
#define	  ATMEL_TSADCC_SLEEP	(1    <<  5)	/* Sleep mode */
#define	  ATMEL_TSADCC_PENDET	(1    <<  6)	/* Pen Detect selection */
#define	  ATMEL_TSADCC_PRESCAL	(0x3f <<  8)	/* Prescalar Rate Selection */
#define	  ATMEL_TSADCC_STARTUP	(0x7f << 16)	/* Start Up time */
#define	  ATMEL_TSADCC_SHTIM	(0xf  << 24)	/* Sample & Hold time */
#define	  ATMEL_TSADCC_PENDBC	(0xf  << 28)	/* Pen Detect debouncing time */

#define ATMEL_TSADCC_TRGR	0x08	/* Trigger register */
#define	  ATMEL_TSADCC_TRGMOD	(7      <<  0)	/* Trigger mode */
#define	    ATMEL_TSADCC_TRGMOD_NONE		(0 << 0)
#define     ATMEL_TSADCC_TRGMOD_EXT_RISING	(1 << 0)
#define     ATMEL_TSADCC_TRGMOD_EXT_FALLING	(2 << 0)
#define     ATMEL_TSADCC_TRGMOD_EXT_ANY		(3 << 0)
#define     ATMEL_TSADCC_TRGMOD_PENDET		(4 << 0)
#define     ATMEL_TSADCC_TRGMOD_PERIOD		(5 << 0)
#define     ATMEL_TSADCC_TRGMOD_CONTINUOUS	(6 << 0)
#define   ATMEL_TSADCC_TRGPER	(0xffff << 16)	/* Trigger period */

#define ATMEL_TSADCC_TSR	0x0C	/* Touch Screen register */
#define	  ATMEL_TSADCC_TSFREQ	(0xf <<  0)	/* TS Frequency in Interleaved mode */
#define	  ATMEL_TSADCC_TSSHTIM	(0xf << 24)	/* Sample & Hold time */

#define ATMEL_TSADCC_CHER	0x10	/* Channel Enable register */
#define ATMEL_TSADCC_CHDR	0x14	/* Channel Disable register */
#define ATMEL_TSADCC_CHSR	0x18	/* Channel Status register */
#define	  ATMEL_TSADCC_CH(n)	(1 << (n))	/* Channel number */

#define ATMEL_TSADCC_SR		0x1C	/* Status register */
#define	  ATMEL_TSADCC_EOC(n)	(1 << ((n)+0))	/* End of conversion for channel N */
#define	  ATMEL_TSADCC_OVRE(n)	(1 << ((n)+8))	/* Overrun error for channel N */
#define	  ATMEL_TSADCC_DRDY	(1 << 16)	/* Data Ready */
#define	  ATMEL_TSADCC_GOVRE	(1 << 17)	/* General Overrun Error */
#define	  ATMEL_TSADCC_ENDRX	(1 << 18)	/* End of RX Buffer */
#define	  ATMEL_TSADCC_RXBUFF	(1 << 19)	/* TX Buffer full */
#define	  ATMEL_TSADCC_PENCNT	(1 << 20)	/* Pen contact */
#define	  ATMEL_TSADCC_NOCNT	(1 << 21)	/* No contact */

#define ATMEL_TSADCC_LCDR	0x20	/* Last Converted Data register */
#define	  ATMEL_TSADCC_DATA	(0x3ff << 0)	/* Channel data */

#define ATMEL_TSADCC_IER	0x24	/* Interrupt Enable register */
#define ATMEL_TSADCC_IDR	0x28	/* Interrupt Disable register */
#define ATMEL_TSADCC_IMR	0x2C	/* Interrupt Mask register */
#define ATMEL_TSADCC_CDR0	0x30	/* Channel Data 0 */
#define ATMEL_TSADCC_CDR1	0x34	/* Channel Data 1 */
#define ATMEL_TSADCC_CDR2	0x38	/* Channel Data 2 */
#define ATMEL_TSADCC_CDR3	0x3C	/* Channel Data 3 */
#define ATMEL_TSADCC_CDR4	0x40	/* Channel Data 4 */
#define ATMEL_TSADCC_CDR5	0x44	/* Channel Data 5 */

#define ADC_CLOCK	1000000

struct atmel_tsadcc {
	struct input_dev	*input;
	char			phys[32];
	struct clk		*clk;
	int			irq;
	unsigned int		prev_absx;
	unsigned int		prev_absy;
	unsigned char		bufferedmeasure;
};

static void __iomem		*tsc_base;

#define atmel_tsadcc_read(reg)		__raw_readl(tsc_base + (reg))
#define atmel_tsadcc_write(reg, val)	__raw_writel((val), tsc_base + (reg))

static irqreturn_t atmel_tsadcc_interrupt(int irq, void *dev)
{
	struct atmel_tsadcc	*ts_dev = (struct atmel_tsadcc *)dev;
	struct input_dev	*input_dev = ts_dev->input;

	unsigned int status;
	unsigned int reg;

	status = atmel_tsadcc_read(ATMEL_TSADCC_SR);
	status &= atmel_tsadcc_read(ATMEL_TSADCC_IMR);

	if (status & ATMEL_TSADCC_NOCNT) {
		/* Contact lost */
		reg = atmel_tsadcc_read(ATMEL_TSADCC_MR) | ATMEL_TSADCC_PENDBC;

		atmel_tsadcc_write(ATMEL_TSADCC_MR, reg);
		atmel_tsadcc_write(ATMEL_TSADCC_TRGR, ATMEL_TSADCC_TRGMOD_NONE);
		atmel_tsadcc_write(ATMEL_TSADCC_IDR,
				   ATMEL_TSADCC_EOC(3) | ATMEL_TSADCC_NOCNT);
		atmel_tsadcc_write(ATMEL_TSADCC_IER, ATMEL_TSADCC_PENCNT);

		input_report_key(input_dev, BTN_TOUCH, 0);
		ts_dev->bufferedmeasure = 0;
		input_sync(input_dev);

	} else if (status & ATMEL_TSADCC_PENCNT) {
		/* Pen detected */
		reg = atmel_tsadcc_read(ATMEL_TSADCC_MR);
		reg &= ~ATMEL_TSADCC_PENDBC;

		atmel_tsadcc_write(ATMEL_TSADCC_IDR, ATMEL_TSADCC_PENCNT);
		atmel_tsadcc_write(ATMEL_TSADCC_MR, reg);
		atmel_tsadcc_write(ATMEL_TSADCC_IER,
				   ATMEL_TSADCC_EOC(3) | ATMEL_TSADCC_NOCNT);
		atmel_tsadcc_write(ATMEL_TSADCC_TRGR,
				   ATMEL_TSADCC_TRGMOD_PERIOD | (0x0FFF << 16));

	} else if (status & ATMEL_TSADCC_EOC(3)) {
		/* Conversion finished */

		if (ts_dev->bufferedmeasure) {
			/* Last measurement is always discarded, since it can
			 * be erroneous.
			 * Always report previous measurement */
			input_report_abs(input_dev, ABS_X, ts_dev->prev_absx);
			input_report_abs(input_dev, ABS_Y, ts_dev->prev_absy);
			input_report_key(input_dev, BTN_TOUCH, 1);
			input_sync(input_dev);
		} else
			ts_dev->bufferedmeasure = 1;

		/* Now make new measurement */
		ts_dev->prev_absx = atmel_tsadcc_read(ATMEL_TSADCC_CDR3) << 10;
		ts_dev->prev_absx /= atmel_tsadcc_read(ATMEL_TSADCC_CDR2);

		ts_dev->prev_absy = atmel_tsadcc_read(ATMEL_TSADCC_CDR1) << 10;
		ts_dev->prev_absy /= atmel_tsadcc_read(ATMEL_TSADCC_CDR0);
	}

	return IRQ_HANDLED;
}

/*
 * The functions for inserting/removing us as a module.
 */

static int __devinit atmel_tsadcc_probe(struct platform_device *pdev)
{
	struct atmel_tsadcc	*ts_dev;
	struct input_dev	*input_dev;
	struct resource		*res;
	int		err = 0;
	unsigned int	prsc;
	unsigned int	reg;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		dev_err(&pdev->dev, "no mmio resource defined.\n");
		return -ENXIO;
	}

	/* Allocate memory for device */
	ts_dev = kzalloc(sizeof(struct atmel_tsadcc), GFP_KERNEL);
	if (!ts_dev) {
		dev_err(&pdev->dev, "failed to allocate memory.\n");
		return -ENOMEM;
	}
	platform_set_drvdata(pdev, ts_dev);

	input_dev = input_allocate_device();
	if (!input_dev) {
		dev_err(&pdev->dev, "failed to allocate input device.\n");
		err = -EBUSY;
		goto err_free_mem;
	}

	ts_dev->irq = platform_get_irq(pdev, 0);
	if (ts_dev->irq < 0) {
		dev_err(&pdev->dev, "no irq ID is designated.\n");
		err = -ENODEV;
		goto err_free_dev;
	}

	if (!request_mem_region(res->start, resource_size(res),
				"atmel tsadcc regs")) {
		dev_err(&pdev->dev, "resources is unavailable.\n");
		err = -EBUSY;
		goto err_free_dev;
	}

	tsc_base = ioremap(res->start, resource_size(res));
	if (!tsc_base) {
		dev_err(&pdev->dev, "failed to map registers.\n");
		err = -ENOMEM;
		goto err_release_mem;
	}

	err = request_irq(ts_dev->irq, atmel_tsadcc_interrupt, IRQF_DISABLED,
			pdev->dev.driver->name, ts_dev);
	if (err) {
		dev_err(&pdev->dev, "failed to allocate irq.\n");
		goto err_unmap_regs;
	}

	ts_dev->clk = clk_get(&pdev->dev, "tsc_clk");
	if (IS_ERR(ts_dev->clk)) {
		dev_err(&pdev->dev, "failed to get ts_clk\n");
		err = PTR_ERR(ts_dev->clk);
		goto err_free_irq;
	}

	ts_dev->input = input_dev;
	ts_dev->bufferedmeasure = 0;

	snprintf(ts_dev->phys, sizeof(ts_dev->phys),
		 "%s/input0", dev_name(&pdev->dev));

	input_dev->name = "atmel touch screen controller";
	input_dev->phys = ts_dev->phys;
	input_dev->dev.parent = &pdev->dev;

	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

	input_set_abs_params(input_dev, ABS_X, 0, 0x3FF, 0, 0);
	input_set_abs_params(input_dev, ABS_Y, 0, 0x3FF, 0, 0);

	/* clk_enable() always returns 0, no need to check it */
	clk_enable(ts_dev->clk);

	prsc = clk_get_rate(ts_dev->clk);
	dev_info(&pdev->dev, "Master clock is set at: %d Hz\n", prsc);

	prsc = prsc / ADC_CLOCK / 2 - 1;

	reg = ATMEL_TSADCC_TSAMOD_TS_ONLY_MODE		|
		((0x00 << 5) & ATMEL_TSADCC_SLEEP)	|	/* Normal Mode */
		((0x01 << 6) & ATMEL_TSADCC_PENDET)	|	/* Enable Pen Detect */
		((prsc << 8) & ATMEL_TSADCC_PRESCAL)	|	/* PRESCAL */
		((0x13 << 16) & ATMEL_TSADCC_STARTUP)	|	/* STARTUP */
		((0x0F << 28) & ATMEL_TSADCC_PENDBC);		/* PENDBC */

	atmel_tsadcc_write(ATMEL_TSADCC_CR, ATMEL_TSADCC_SWRST);
	atmel_tsadcc_write(ATMEL_TSADCC_MR, reg);
	atmel_tsadcc_write(ATMEL_TSADCC_TRGR, ATMEL_TSADCC_TRGMOD_NONE);
	atmel_tsadcc_write(ATMEL_TSADCC_TSR, (0x3 << 24) & ATMEL_TSADCC_TSSHTIM);

	atmel_tsadcc_read(ATMEL_TSADCC_SR);
	atmel_tsadcc_write(ATMEL_TSADCC_IER, ATMEL_TSADCC_PENCNT);

	/* All went ok, so register to the input system */
	err = input_register_device(input_dev);
	if (err)
		goto err_fail;

	return 0;

err_fail:
	clk_disable(ts_dev->clk);
	clk_put(ts_dev->clk);
err_free_irq:
	free_irq(ts_dev->irq, ts_dev);
err_unmap_regs:
	iounmap(tsc_base);
err_release_mem:
	release_mem_region(res->start, resource_size(res));
err_free_dev:
	input_free_device(ts_dev->input);
err_free_mem:
	kfree(ts_dev);
	return err;
}

static int __devexit atmel_tsadcc_remove(struct platform_device *pdev)
{
	struct atmel_tsadcc *ts_dev = dev_get_drvdata(&pdev->dev);
	struct resource *res;

	free_irq(ts_dev->irq, ts_dev);

	input_unregister_device(ts_dev->input);

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

	clk_disable(ts_dev->clk);
	clk_put(ts_dev->clk);

	kfree(ts_dev);

	return 0;
}

static struct platform_driver atmel_tsadcc_driver = {
	.probe		= atmel_tsadcc_probe,
	.remove		= __devexit_p(atmel_tsadcc_remove),
	.driver		= {
		.name	= "atmel_tsadcc",
	},
};

static int __init atmel_tsadcc_init(void)
{
	return platform_driver_register(&atmel_tsadcc_driver);
}

static void __exit atmel_tsadcc_exit(void)
{
	platform_driver_unregister(&atmel_tsadcc_driver);
}

module_init(atmel_tsadcc_init);
module_exit(atmel_tsadcc_exit);


MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Atmel TouchScreen Driver");
MODULE_AUTHOR("Dan Liang <dan.liang@atmel.com>");

OpenPOWER on IntegriCloud