aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/input/touchscreen/sun4i-ts.c
blob: c0116994067d5cf46503a14d51de62a33a2ea05b (plain) (blame)
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
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
/*
 * Allwinner sunxi resistive touchscreen controller driver
 *
 * Copyright (C) 2013 - 2014 Hans de Goede <hdegoede@redhat.com>
 *
 * The hwmon parts are based on work by Corentin LABBE which is:
 * Copyright (C) 2013 Corentin LABBE <clabbe.montjoie@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

/*
 * The sun4i-ts controller is capable of detecting a second touch, but when a
 * second touch is present then the accuracy becomes so bad the reported touch
 * location is not useable.
 *
 * The original android driver contains some complicated heuristics using the
 * aprox. distance between the 2 touches to see if the user is making a pinch
 * open / close movement, and then reports emulated multi-touch events around
 * the last touch coordinate (as the dual-touch coordinates are worthless).
 *
 * These kinds of heuristics are just asking for trouble (and don't belong
 * in the kernel). So this driver offers straight forward, reliable single
 * touch functionality only.
 *
 * s.a. A20 User Manual "1.15 TP" (Documentation/arm/sunxi/README)
 * (looks like the description in the A20 User Manual v1.3 is better
 * than the one in the A10 User Manual v.1.5)
 */

#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/thermal.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#define TP_CTRL0		0x00
#define TP_CTRL1		0x04
#define TP_CTRL2		0x08
#define TP_CTRL3		0x0c
#define TP_INT_FIFOC		0x10
#define TP_INT_FIFOS		0x14
#define TP_TPR			0x18
#define TP_CDAT			0x1c
#define TEMP_DATA		0x20
#define TP_DATA			0x24

/* TP_CTRL0 bits */
#define ADC_FIRST_DLY(x)	((x) << 24) /* 8 bits */
#define ADC_FIRST_DLY_MODE(x)	((x) << 23)
#define ADC_CLK_SEL(x)		((x) << 22)
#define ADC_CLK_DIV(x)		((x) << 20) /* 3 bits */
#define FS_DIV(x)		((x) << 16) /* 4 bits */
#define T_ACQ(x)		((x) << 0) /* 16 bits */

/* TP_CTRL1 bits */
#define STYLUS_UP_DEBOUN(x)	((x) << 12) /* 8 bits */
#define STYLUS_UP_DEBOUN_EN(x)	((x) << 9)
#define TOUCH_PAN_CALI_EN(x)	((x) << 6)
#define TP_DUAL_EN(x)		((x) << 5)
#define TP_MODE_EN(x)		((x) << 4)
#define TP_ADC_SELECT(x)	((x) << 3)
#define ADC_CHAN_SELECT(x)	((x) << 0)  /* 3 bits */

/* on sun6i, bits 3~6 are left shifted by 1 to 4~7 */
#define SUN6I_TP_MODE_EN(x)	((x) << 5)

/* TP_CTRL2 bits */
#define TP_SENSITIVE_ADJUST(x)	((x) << 28) /* 4 bits */
#define TP_MODE_SELECT(x)	((x) << 26) /* 2 bits */
#define PRE_MEA_EN(x)		((x) << 24)
#define PRE_MEA_THRE_CNT(x)	((x) << 0) /* 24 bits */

/* TP_CTRL3 bits */
#define FILTER_EN(x)		((x) << 2)
#define FILTER_TYPE(x)		((x) << 0)  /* 2 bits */

/* TP_INT_FIFOC irq and fifo mask / control bits */
#define TEMP_IRQ_EN(x)		((x) << 18)
#define OVERRUN_IRQ_EN(x)	((x) << 17)
#define DATA_IRQ_EN(x)		((x) << 16)
#define TP_DATA_XY_CHANGE(x)	((x) << 13)
#define FIFO_TRIG(x)		((x) << 8)  /* 5 bits */
#define DATA_DRQ_EN(x)		((x) << 7)
#define FIFO_FLUSH(x)		((x) << 4)
#define TP_UP_IRQ_EN(x)		((x) << 1)
#define TP_DOWN_IRQ_EN(x)	((x) << 0)

/* TP_INT_FIFOS irq and fifo status bits */
#define TEMP_DATA_PENDING	BIT(18)
#define FIFO_OVERRUN_PENDING	BIT(17)
#define FIFO_DATA_PENDING	BIT(16)
#define TP_IDLE_FLG		BIT(2)
#define TP_UP_PENDING		BIT(1)
#define TP_DOWN_PENDING		BIT(0)

/* TP_TPR bits */
#define TEMP_ENABLE(x)		((x) << 16)
#define TEMP_PERIOD(x)		((x) << 0)  /* t = x * 256 * 16 / clkin */

struct sun4i_ts_data {
	struct device *dev;
	struct input_dev *input;
	struct thermal_zone_device *tz;
	void __iomem *base;
	unsigned int irq;
	bool ignore_fifo_data;
	int temp_data;
	int temp_offset;
	int temp_step;
};

static void sun4i_ts_irq_handle_input(struct sun4i_ts_data *ts, u32 reg_val)
{
	u32 x, y;

	if (reg_val & FIFO_DATA_PENDING) {
		x = readl(ts->base + TP_DATA);
		y = readl(ts->base + TP_DATA);
		/* The 1st location reported after an up event is unreliable */
		if (!ts->ignore_fifo_data) {
			input_report_abs(ts->input, ABS_X, x);
			input_report_abs(ts->input, ABS_Y, y);
			/*
			 * The hardware has a separate down status bit, but
			 * that gets set before we get the first location,
			 * resulting in reporting a click on the old location.
			 */
			input_report_key(ts->input, BTN_TOUCH, 1);
			input_sync(ts->input);
		} else {
			ts->ignore_fifo_data = false;
		}
	}

	if (reg_val & TP_UP_PENDING) {
		ts->ignore_fifo_data = true;
		input_report_key(ts->input, BTN_TOUCH, 0);
		input_sync(ts->input);
	}
}

static irqreturn_t sun4i_ts_irq(int irq, void *dev_id)
{
	struct sun4i_ts_data *ts = dev_id;
	u32 reg_val;

	reg_val  = readl(ts->base + TP_INT_FIFOS);

	if (reg_val & TEMP_DATA_PENDING)
		ts->temp_data = readl(ts->base + TEMP_DATA);

	if (ts->input)
		sun4i_ts_irq_handle_input(ts, reg_val);

	writel(reg_val, ts->base + TP_INT_FIFOS);

	return IRQ_HANDLED;
}

static int sun4i_ts_open(struct input_dev *dev)
{
	struct sun4i_ts_data *ts = input_get_drvdata(dev);

	/* Flush, set trig level to 1, enable temp, data and up irqs */
	writel(TEMP_IRQ_EN(1) | DATA_IRQ_EN(1) | FIFO_TRIG(1) | FIFO_FLUSH(1) |
		TP_UP_IRQ_EN(1), ts->base + TP_INT_FIFOC);

	return 0;
}

static void sun4i_ts_close(struct input_dev *dev)
{
	struct sun4i_ts_data *ts = input_get_drvdata(dev);

	/* Deactivate all input IRQs */
	writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
}

static int sun4i_get_temp(const struct sun4i_ts_data *ts, long *temp)
{
	/* No temp_data until the first irq */
	if (ts->temp_data == -1)
		return -EAGAIN;

	*temp = ts->temp_data * ts->temp_step - ts->temp_offset;

	return 0;
}

static int sun4i_get_tz_temp(void *data, long *temp)
{
	return sun4i_get_temp(data, temp);
}

static struct thermal_zone_of_device_ops sun4i_ts_tz_ops = {
	.get_temp = sun4i_get_tz_temp,
};

static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
			 char *buf)
{
	struct sun4i_ts_data *ts = dev_get_drvdata(dev);
	long temp;
	int error;

	error = sun4i_get_temp(ts, &temp);
	if (error)
		return error;

	return sprintf(buf, "%ld\n", temp);
}

static ssize_t show_temp_label(struct device *dev,
			      struct device_attribute *devattr, char *buf)
{
	return sprintf(buf, "SoC temperature\n");
}

static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL);
static DEVICE_ATTR(temp1_label, S_IRUGO, show_temp_label, NULL);

static struct attribute *sun4i_ts_attrs[] = {
	&dev_attr_temp1_input.attr,
	&dev_attr_temp1_label.attr,
	NULL
};
ATTRIBUTE_GROUPS(sun4i_ts);

static int sun4i_ts_probe(struct platform_device *pdev)
{
	struct sun4i_ts_data *ts;
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct device *hwmon;
	int error;
	u32 reg;
	bool ts_attached;
	u32 tp_sensitive_adjust = 15;
	u32 filter_type = 1;

	ts = devm_kzalloc(dev, sizeof(struct sun4i_ts_data), GFP_KERNEL);
	if (!ts)
		return -ENOMEM;

	ts->dev = dev;
	ts->ignore_fifo_data = true;
	ts->temp_data = -1;
	if (of_device_is_compatible(np, "allwinner,sun6i-a31-ts")) {
		/* Allwinner SDK has temperature (C) = (value / 6) - 271 */
		ts->temp_offset = 271000;
		ts->temp_step = 167;
	} else if (of_device_is_compatible(np, "allwinner,sun4i-a10-ts")) {
		/*
		 * The A10 temperature sensor has quite a wide spread, these
		 * parameters are based on the averaging of the calibration
		 * results of 4 completely different boards, with a spread of
		 * temp_step from 0.096 - 0.170 and temp_offset from 176 - 331.
		 */
		ts->temp_offset = 257000;
		ts->temp_step = 133;
	} else {
		/*
		 * The user manuals do not contain the formula for calculating
		 * the temperature. The formula used here is from the AXP209,
		 * which is designed by X-Powers, an affiliate of Allwinner:
		 *
		 *     temperature (C) = (value * 0.1) - 144.7
		 *
		 * Allwinner does not have any documentation whatsoever for
		 * this hardware. Moreover, it is claimed that the sensor
		 * is inaccurate and cannot work properly.
		 */
		ts->temp_offset = 144700;
		ts->temp_step = 100;
	}

	ts_attached = of_property_read_bool(np, "allwinner,ts-attached");
	if (ts_attached) {
		ts->input = devm_input_allocate_device(dev);
		if (!ts->input)
			return -ENOMEM;

		ts->input->name = pdev->name;
		ts->input->phys = "sun4i_ts/input0";
		ts->input->open = sun4i_ts_open;
		ts->input->close = sun4i_ts_close;
		ts->input->id.bustype = BUS_HOST;
		ts->input->id.vendor = 0x0001;
		ts->input->id.product = 0x0001;
		ts->input->id.version = 0x0100;
		ts->input->evbit[0] =  BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS);
		__set_bit(BTN_TOUCH, ts->input->keybit);
		input_set_abs_params(ts->input, ABS_X, 0, 4095, 0, 0);
		input_set_abs_params(ts->input, ABS_Y, 0, 4095, 0, 0);
		input_set_drvdata(ts->input, ts);
	}

	ts->base = devm_ioremap_resource(dev,
			      platform_get_resource(pdev, IORESOURCE_MEM, 0));
	if (IS_ERR(ts->base))
		return PTR_ERR(ts->base);

	ts->irq = platform_get_irq(pdev, 0);
	error = devm_request_irq(dev, ts->irq, sun4i_ts_irq, 0, "sun4i-ts", ts);
	if (error)
		return error;

	/*
	 * Select HOSC clk, clkin = clk / 6, adc samplefreq = clkin / 8192,
	 * t_acq = clkin / (16 * 64)
	 */
	writel(ADC_CLK_SEL(0) | ADC_CLK_DIV(2) | FS_DIV(7) | T_ACQ(63),
	       ts->base + TP_CTRL0);

	/*
	 * tp_sensitive_adjust is an optional property
	 * tp_mode = 0 : only x and y coordinates, as we don't use dual touch
	 */
	of_property_read_u32(np, "allwinner,tp-sensitive-adjust",
			     &tp_sensitive_adjust);
	writel(TP_SENSITIVE_ADJUST(tp_sensitive_adjust) | TP_MODE_SELECT(0),
	       ts->base + TP_CTRL2);

	/*
	 * Enable median and averaging filter, optional property for
	 * filter type.
	 */
	of_property_read_u32(np, "allwinner,filter-type", &filter_type);
	writel(FILTER_EN(1) | FILTER_TYPE(filter_type), ts->base + TP_CTRL3);

	/* Enable temperature measurement, period 1953 (2 seconds) */
	writel(TEMP_ENABLE(1) | TEMP_PERIOD(1953), ts->base + TP_TPR);

	/*
	 * Set stylus up debounce to aprox 10 ms, enable debounce, and
	 * finally enable tp mode.
	 */
	reg = STYLUS_UP_DEBOUN(5) | STYLUS_UP_DEBOUN_EN(1);
	if (of_device_is_compatible(np, "allwinner,sun6i-a31-ts"))
		reg |= SUN6I_TP_MODE_EN(1);
	else
		reg |= TP_MODE_EN(1);
	writel(reg, ts->base + TP_CTRL1);

	/*
	 * The thermal core does not register hwmon devices for DT-based
	 * thermal zone sensors, such as this one.
	 */
	hwmon = devm_hwmon_device_register_with_groups(ts->dev, "sun4i_ts",
						       ts, sun4i_ts_groups);
	if (IS_ERR(hwmon))
		return PTR_ERR(hwmon);

	ts->tz = thermal_zone_of_sensor_register(ts->dev, 0, ts,
						 &sun4i_ts_tz_ops);
	if (IS_ERR(ts->tz))
		ts->tz = NULL;

	writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC);

	if (ts_attached) {
		error = input_register_device(ts->input);
		if (error) {
			writel(0, ts->base + TP_INT_FIFOC);
			thermal_zone_of_sensor_unregister(ts->dev, ts->tz);
			return error;
		}
	}

	platform_set_drvdata(pdev, ts);
	return 0;
}

static int sun4i_ts_remove(struct platform_device *pdev)
{
	struct sun4i_ts_data *ts = platform_get_drvdata(pdev);

	/* Explicit unregister to avoid open/close changing the imask later */
	if (ts->input)
		input_unregister_device(ts->input);

	thermal_zone_of_sensor_unregister(ts->dev, ts->tz);

	/* Deactivate all IRQs */
	writel(0, ts->base + TP_INT_FIFOC);

	return 0;
}

static const struct of_device_id sun4i_ts_of_match[] = {
	{ .compatible = "allwinner,sun4i-a10-ts", },
	{ .compatible = "allwinner,sun5i-a13-ts", },
	{ .compatible = "allwinner,sun6i-a31-ts", },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, sun4i_ts_of_match);

static struct platform_driver sun4i_ts_driver = {
	.driver = {
		.name	= "sun4i-ts",
		.of_match_table = of_match_ptr(sun4i_ts_of_match),
	},
	.probe	= sun4i_ts_probe,
	.remove	= sun4i_ts_remove,
};

module_platform_driver(sun4i_ts_driver);

MODULE_DESCRIPTION("Allwinner sun4i resistive touchscreen controller driver");
MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
MODULE_LICENSE("GPL");