aboutsummaryrefslogtreecommitdiff
path: root/drivers/gpio/gpio-ts5500.c
blob: c91890488402539ddff45ffb8d540be1d629bb2d (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
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
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
// SPDX-License-Identifier: GPL-2.0
/*
 * Digital I/O driver for Technologic Systems TS-5500
 *
 * Copyright (c) 2012 Savoir-faire Linux Inc.
 *	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
 *
 * Technologic Systems platforms have pin blocks, exposing several Digital
 * Input/Output lines (DIO). This driver aims to support single pin blocks.
 * In that sense, the support is not limited to the TS-5500 blocks.
 * Actually, the following platforms have DIO support:
 *
 * TS-5500:
 *   Documentation: http://wiki.embeddedarm.com/wiki/TS-5500
 *   Blocks: DIO1, DIO2 and LCD port.
 *
 * TS-5600:
 *   Documentation: http://wiki.embeddedarm.com/wiki/TS-5600
 *   Blocks: LCD port (identical to TS-5500 LCD).
 */

#include <linux/bitops.h>
#include <linux/gpio/driver.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

/* List of supported Technologic Systems platforms DIO blocks */
enum ts5500_blocks { TS5500_DIO1, TS5500_DIO2, TS5500_LCD, TS5600_LCD };

struct ts5500_priv {
	const struct ts5500_dio *pinout;
	struct gpio_chip gpio_chip;
	spinlock_t lock;
	bool strap;
	u8 hwirq;
};

/*
 * Hex 7D is used to control several blocks (e.g. DIO2 and LCD port).
 * This flag ensures that the region has been requested by this driver.
 */
static bool hex7d_reserved;

/*
 * This structure is used to describe capabilities of DIO lines,
 * such as available directions and connected interrupt (if any).
 */
struct ts5500_dio {
	const u8 value_addr;
	const u8 value_mask;
	const u8 control_addr;
	const u8 control_mask;
	const bool no_input;
	const bool no_output;
	const u8 irq;
};

#define TS5500_DIO_IN_OUT(vaddr, vbit, caddr, cbit)	\
	{						\
		.value_addr = vaddr,			\
		.value_mask = BIT(vbit),		\
		.control_addr = caddr,			\
		.control_mask = BIT(cbit),		\
	}

#define TS5500_DIO_IN(addr, bit)		\
	{					\
		.value_addr = addr,		\
		.value_mask = BIT(bit),		\
		.no_output = true,		\
	}

#define TS5500_DIO_IN_IRQ(addr, bit, _irq)	\
	{					\
		.value_addr = addr,		\
		.value_mask = BIT(bit),		\
		.no_output = true,		\
		.irq = _irq,			\
	}

#define TS5500_DIO_OUT(addr, bit)		\
	{					\
		.value_addr = addr,		\
		.value_mask = BIT(bit),		\
		.no_input = true,		\
	}

/*
 * Input/Output DIO lines are programmed in groups of 4. Their values are
 * available through 4 consecutive bits in a value port, whereas the direction
 * of these 4 lines is driven by only 1 bit in a control port.
 */
#define TS5500_DIO_GROUP(vaddr, vbitfrom, caddr, cbit)		\
	TS5500_DIO_IN_OUT(vaddr, vbitfrom + 0, caddr, cbit),	\
	TS5500_DIO_IN_OUT(vaddr, vbitfrom + 1, caddr, cbit),	\
	TS5500_DIO_IN_OUT(vaddr, vbitfrom + 2, caddr, cbit),	\
	TS5500_DIO_IN_OUT(vaddr, vbitfrom + 3, caddr, cbit)

/*
 * TS-5500 DIO1 block
 *
 *  value    control  dir    hw
 *  addr bit addr bit in out irq name     pin offset
 *
 *  0x7b  0  0x7a  0  x   x      DIO1_0   1   0
 *  0x7b  1  0x7a  0  x   x      DIO1_1   3   1
 *  0x7b  2  0x7a  0  x   x      DIO1_2   5   2
 *  0x7b  3  0x7a  0  x   x      DIO1_3   7   3
 *  0x7b  4  0x7a  1  x   x      DIO1_4   9   4
 *  0x7b  5  0x7a  1  x   x      DIO1_5   11  5
 *  0x7b  6  0x7a  1  x   x      DIO1_6   13  6
 *  0x7b  7  0x7a  1  x   x      DIO1_7   15  7
 *  0x7c  0  0x7a  5  x   x      DIO1_8   4   8
 *  0x7c  1  0x7a  5  x   x      DIO1_9   6   9
 *  0x7c  2  0x7a  5  x   x      DIO1_10  8   10
 *  0x7c  3  0x7a  5  x   x      DIO1_11  10  11
 *  0x7c  4           x          DIO1_12  12  12
 *  0x7c  5           x      7   DIO1_13  14  13
 */
static const struct ts5500_dio ts5500_dio1[] = {
	TS5500_DIO_GROUP(0x7b, 0, 0x7a, 0),
	TS5500_DIO_GROUP(0x7b, 4, 0x7a, 1),
	TS5500_DIO_GROUP(0x7c, 0, 0x7a, 5),
	TS5500_DIO_IN(0x7c, 4),
	TS5500_DIO_IN_IRQ(0x7c, 5, 7),
};

/*
 * TS-5500 DIO2 block
 *
 *  value    control  dir    hw
 *  addr bit addr bit in out irq name     pin offset
 *
 *  0x7e  0  0x7d  0  x   x      DIO2_0   1   0
 *  0x7e  1  0x7d  0  x   x      DIO2_1   3   1
 *  0x7e  2  0x7d  0  x   x      DIO2_2   5   2
 *  0x7e  3  0x7d  0  x   x      DIO2_3   7   3
 *  0x7e  4  0x7d  1  x   x      DIO2_4   9   4
 *  0x7e  5  0x7d  1  x   x      DIO2_5   11  5
 *  0x7e  6  0x7d  1  x   x      DIO2_6   13  6
 *  0x7e  7  0x7d  1  x   x      DIO2_7   15  7
 *  0x7f  0  0x7d  5  x   x      DIO2_8   4   8
 *  0x7f  1  0x7d  5  x   x      DIO2_9   6   9
 *  0x7f  2  0x7d  5  x   x      DIO2_10  8   10
 *  0x7f  3  0x7d  5  x   x      DIO2_11  10  11
 *  0x7f  4           x      6   DIO2_13  14  12
 */
static const struct ts5500_dio ts5500_dio2[] = {
	TS5500_DIO_GROUP(0x7e, 0, 0x7d, 0),
	TS5500_DIO_GROUP(0x7e, 4, 0x7d, 1),
	TS5500_DIO_GROUP(0x7f, 0, 0x7d, 5),
	TS5500_DIO_IN_IRQ(0x7f, 4, 6),
};

/*
 * TS-5500 LCD port used as DIO block
 * TS-5600 LCD port is identical
 *
 *  value    control  dir    hw
 *  addr bit addr bit in out irq name    pin offset
 *
 *  0x72  0  0x7d  2  x   x      LCD_0   8   0
 *  0x72  1  0x7d  2  x   x      LCD_1   7   1
 *  0x72  2  0x7d  2  x   x      LCD_2   10  2
 *  0x72  3  0x7d  2  x   x      LCD_3   9   3
 *  0x72  4  0x7d  3  x   x      LCD_4   12  4
 *  0x72  5  0x7d  3  x   x      LCD_5   11  5
 *  0x72  6  0x7d  3  x   x      LCD_6   14  6
 *  0x72  7  0x7d  3  x   x      LCD_7   13  7
 *  0x73  0               x      LCD_EN  5   8
 *  0x73  6           x          LCD_WR  6   9
 *  0x73  7           x      1   LCD_RS  3   10
 */
static const struct ts5500_dio ts5500_lcd[] = {
	TS5500_DIO_GROUP(0x72, 0, 0x7d, 2),
	TS5500_DIO_GROUP(0x72, 4, 0x7d, 3),
	TS5500_DIO_OUT(0x73, 0),
	TS5500_DIO_IN(0x73, 6),
	TS5500_DIO_IN_IRQ(0x73, 7, 1),
};

static inline void ts5500_set_mask(u8 mask, u8 addr)
{
	u8 val = inb(addr);
	val |= mask;
	outb(val, addr);
}

static inline void ts5500_clear_mask(u8 mask, u8 addr)
{
	u8 val = inb(addr);
	val &= ~mask;
	outb(val, addr);
}

static int ts5500_gpio_input(struct gpio_chip *chip, unsigned offset)
{
	struct ts5500_priv *priv = gpiochip_get_data(chip);
	const struct ts5500_dio line = priv->pinout[offset];
	unsigned long flags;

	if (line.no_input)
		return -ENXIO;

	if (line.no_output)
		return 0;

	spin_lock_irqsave(&priv->lock, flags);
	ts5500_clear_mask(line.control_mask, line.control_addr);
	spin_unlock_irqrestore(&priv->lock, flags);

	return 0;
}

static int ts5500_gpio_get(struct gpio_chip *chip, unsigned offset)
{
	struct ts5500_priv *priv = gpiochip_get_data(chip);
	const struct ts5500_dio line = priv->pinout[offset];

	return !!(inb(line.value_addr) & line.value_mask);
}

static int ts5500_gpio_output(struct gpio_chip *chip, unsigned offset, int val)
{
	struct ts5500_priv *priv = gpiochip_get_data(chip);
	const struct ts5500_dio line = priv->pinout[offset];
	unsigned long flags;

	if (line.no_output)
		return -ENXIO;

	spin_lock_irqsave(&priv->lock, flags);
	if (!line.no_input)
		ts5500_set_mask(line.control_mask, line.control_addr);

	if (val)
		ts5500_set_mask(line.value_mask, line.value_addr);
	else
		ts5500_clear_mask(line.value_mask, line.value_addr);
	spin_unlock_irqrestore(&priv->lock, flags);

	return 0;
}

static void ts5500_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
{
	struct ts5500_priv *priv = gpiochip_get_data(chip);
	const struct ts5500_dio line = priv->pinout[offset];
	unsigned long flags;

	spin_lock_irqsave(&priv->lock, flags);
	if (val)
		ts5500_set_mask(line.value_mask, line.value_addr);
	else
		ts5500_clear_mask(line.value_mask, line.value_addr);
	spin_unlock_irqrestore(&priv->lock, flags);
}

static int ts5500_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
	struct ts5500_priv *priv = gpiochip_get_data(chip);
	const struct ts5500_dio *block = priv->pinout;
	const struct ts5500_dio line = block[offset];

	/* Only one pin is connected to an interrupt */
	if (line.irq)
		return line.irq;

	/* As this pin is input-only, we may strap it to another in/out pin */
	if (priv->strap)
		return priv->hwirq;

	return -ENXIO;
}

static int ts5500_enable_irq(struct ts5500_priv *priv)
{
	int ret = 0;
	unsigned long flags;

	spin_lock_irqsave(&priv->lock, flags);
	if (priv->hwirq == 7)
		ts5500_set_mask(BIT(7), 0x7a); /* DIO1_13 on IRQ7 */
	else if (priv->hwirq == 6)
		ts5500_set_mask(BIT(7), 0x7d); /* DIO2_13 on IRQ6 */
	else if (priv->hwirq == 1)
		ts5500_set_mask(BIT(6), 0x7d); /* LCD_RS on IRQ1 */
	else
		ret = -EINVAL;
	spin_unlock_irqrestore(&priv->lock, flags);

	return ret;
}

static void ts5500_disable_irq(struct ts5500_priv *priv)
{
	unsigned long flags;

	spin_lock_irqsave(&priv->lock, flags);
	if (priv->hwirq == 7)
		ts5500_clear_mask(BIT(7), 0x7a); /* DIO1_13 on IRQ7 */
	else if (priv->hwirq == 6)
		ts5500_clear_mask(BIT(7), 0x7d); /* DIO2_13 on IRQ6 */
	else if (priv->hwirq == 1)
		ts5500_clear_mask(BIT(6), 0x7d); /* LCD_RS on IRQ1 */
	else
		dev_err(priv->gpio_chip.parent, "invalid hwirq %d\n",
			priv->hwirq);
	spin_unlock_irqrestore(&priv->lock, flags);
}

static int ts5500_dio_probe(struct platform_device *pdev)
{
	enum ts5500_blocks block = platform_get_device_id(pdev)->driver_data;
	struct device *dev = &pdev->dev;
	const char *name = dev_name(dev);
	struct ts5500_priv *priv;
	struct resource *res;
	unsigned long flags;
	int ret;

	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	if (!res) {
		dev_err(dev, "missing IRQ resource\n");
		return -EINVAL;
	}

	priv = devm_kzalloc(dev, sizeof(struct ts5500_priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	platform_set_drvdata(pdev, priv);
	priv->hwirq = res->start;
	spin_lock_init(&priv->lock);

	priv->gpio_chip.owner = THIS_MODULE;
	priv->gpio_chip.label = name;
	priv->gpio_chip.parent = dev;
	priv->gpio_chip.direction_input = ts5500_gpio_input;
	priv->gpio_chip.direction_output = ts5500_gpio_output;
	priv->gpio_chip.get = ts5500_gpio_get;
	priv->gpio_chip.set = ts5500_gpio_set;
	priv->gpio_chip.to_irq = ts5500_gpio_to_irq;
	priv->gpio_chip.base = -1;

	switch (block) {
	case TS5500_DIO1:
		priv->pinout = ts5500_dio1;
		priv->gpio_chip.ngpio = ARRAY_SIZE(ts5500_dio1);

		if (!devm_request_region(dev, 0x7a, 3, name)) {
			dev_err(dev, "failed to request %s ports\n", name);
			return -EBUSY;
		}
		break;
	case TS5500_DIO2:
		priv->pinout = ts5500_dio2;
		priv->gpio_chip.ngpio = ARRAY_SIZE(ts5500_dio2);

		if (!devm_request_region(dev, 0x7e, 2, name)) {
			dev_err(dev, "failed to request %s ports\n", name);
			return -EBUSY;
		}

		if (hex7d_reserved)
			break;

		if (!devm_request_region(dev, 0x7d, 1, name)) {
			dev_err(dev, "failed to request %s 7D\n", name);
			return -EBUSY;
		}

		hex7d_reserved = true;
		break;
	case TS5500_LCD:
	case TS5600_LCD:
		priv->pinout = ts5500_lcd;
		priv->gpio_chip.ngpio = ARRAY_SIZE(ts5500_lcd);

		if (!devm_request_region(dev, 0x72, 2, name)) {
			dev_err(dev, "failed to request %s ports\n", name);
			return -EBUSY;
		}

		if (!hex7d_reserved) {
			if (!devm_request_region(dev, 0x7d, 1, name)) {
				dev_err(dev, "failed to request %s 7D\n", name);
				return -EBUSY;
			}

			hex7d_reserved = true;
		}

		/* Ensure usage of LCD port as DIO */
		spin_lock_irqsave(&priv->lock, flags);
		ts5500_clear_mask(BIT(4), 0x7d);
		spin_unlock_irqrestore(&priv->lock, flags);
		break;
	}

	ret = devm_gpiochip_add_data(dev, &priv->gpio_chip, priv);
	if (ret) {
		dev_err(dev, "failed to register the gpio chip\n");
		return ret;
	}

	ret = ts5500_enable_irq(priv);
	if (ret) {
		dev_err(dev, "invalid interrupt %d\n", priv->hwirq);
		return ret;
	}

	return 0;
}

static int ts5500_dio_remove(struct platform_device *pdev)
{
	struct ts5500_priv *priv = platform_get_drvdata(pdev);

	ts5500_disable_irq(priv);

	return 0;
}

static const struct platform_device_id ts5500_dio_ids[] = {
	{ "ts5500-dio1", TS5500_DIO1 },
	{ "ts5500-dio2", TS5500_DIO2 },
	{ "ts5500-dio-lcd", TS5500_LCD },
	{ "ts5600-dio-lcd", TS5600_LCD },
	{ }
};
MODULE_DEVICE_TABLE(platform, ts5500_dio_ids);

static struct platform_driver ts5500_dio_driver = {
	.driver = {
		.name = "ts5500-dio",
	},
	.probe = ts5500_dio_probe,
	.remove = ts5500_dio_remove,
	.id_table = ts5500_dio_ids,
};

module_platform_driver(ts5500_dio_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Savoir-faire Linux Inc. <kernel@savoirfairelinux.com>");
MODULE_DESCRIPTION("Technologic Systems TS-5500 Digital I/O driver");