gpio-ts5500.c 12.4 KB
Newer Older
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
/*
 * 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).
 *
 * 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/bitops.h>
#include <linux/gpio.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_data/gpio-ts5500.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 struct ts5500_priv *ts5500_gc_to_priv(struct gpio_chip *chip)
{
	return container_of(chip, struct ts5500_priv, gpio_chip);
}

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 = ts5500_gc_to_priv(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 = ts5500_gc_to_priv(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 = ts5500_gc_to_priv(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 = ts5500_gc_to_priv(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 = ts5500_gc_to_priv(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.dev, "invalid hwirq %d\n", priv->hwirq);
	spin_unlock_irqrestore(&priv->lock, flags);
}

322
static int ts5500_dio_probe(struct platform_device *pdev)
323 324
{
	enum ts5500_blocks block = platform_get_device_id(pdev)->driver_data;
Jingoo Han's avatar
Jingoo Han committed
325
	struct ts5500_dio_platform_data *pdata = dev_get_platdata(&pdev->dev);
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
	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.dev = 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;
	if (pdata) {
		priv->gpio_chip.base = pdata->base;
		priv->strap = pdata->strap;
	}

	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 = gpiochip_add(&priv->gpio_chip);
	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);
		goto cleanup;
	}

	return 0;
cleanup:
430
	gpiochip_remove(&priv->gpio_chip);
431 432 433
	return ret;
}

434
static int ts5500_dio_remove(struct platform_device *pdev)
435 436 437 438
{
	struct ts5500_priv *priv = platform_get_drvdata(pdev);

	ts5500_disable_irq(priv);
439 440
	gpiochip_remove(&priv->gpio_chip);
	return 0;
441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456
}

static 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,
457
	.remove = ts5500_dio_remove,
458 459 460 461 462 463 464 465
	.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");