Free Electrons

Embedded Linux Experts

  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
/*
 * GPIO driver for the SMSC SCH311x Super-I/O chips
 *
 * Copyright (C) 2013 Bruno Randolf <br1@einfach.org>
 *
 * SuperIO functions and chip detection:
 * (c) Copyright 2008 Wim Van Sebroeck <wim@iguana.be>.
 *
 * 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.
 */

#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/bitops.h>
#include <linux/io.h>

#define DRV_NAME			"gpio-sch311x"

#define SCH311X_GPIO_CONF_OUT		0x00
#define SCH311X_GPIO_CONF_IN		0x01
#define SCH311X_GPIO_CONF_INVERT	0x02
#define SCH311X_GPIO_CONF_OPEN_DRAIN	0x80

#define SIO_CONFIG_KEY_ENTER		0x55
#define SIO_CONFIG_KEY_EXIT		0xaa

#define GP1				0x4b

static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e };

static struct platform_device *sch311x_gpio_pdev;

struct sch311x_pdev_data {		/* platform device data */
	unsigned short runtime_reg;	/* runtime register base address */
};

struct sch311x_gpio_block {		/* one GPIO block runtime data */
	struct gpio_chip chip;
	unsigned short data_reg;	/* from definition below */
	unsigned short *config_regs;	/* pointer to definition below */
	unsigned short runtime_reg;	/* runtime register */
	spinlock_t lock;		/* lock for this GPIO block */
};

struct sch311x_gpio_priv {		/* driver private data */
	struct sch311x_gpio_block blocks[6];
};

struct sch311x_gpio_block_def {		/* register address definitions */
	unsigned short data_reg;
	unsigned short config_regs[8];
	unsigned short base;
};

/* Note: some GPIOs are not available, these are marked with 0x00 */

static struct sch311x_gpio_block_def sch311x_gpio_blocks[] = {
	{
		.data_reg = 0x4b,	/* GP1 */
		.config_regs = {0x23, 0x24, 0x25, 0x26, 0x27, 0x29, 0x2a, 0x2b},
		.base = 10,
	},
	{
		.data_reg = 0x4c,	/* GP2 */
		.config_regs = {0x00, 0x2c, 0x2d, 0x00, 0x00, 0x00, 0x00, 0x32},
		.base = 20,
	},
	{
		.data_reg = 0x4d,	/* GP3 */
		.config_regs = {0x33, 0x34, 0x35, 0x36, 0x37, 0x00, 0x39, 0x3a},
		.base = 30,
	},
	{
		.data_reg = 0x4e,	/* GP4 */
		.config_regs = {0x3b, 0x00, 0x3d, 0x00, 0x6e, 0x6f, 0x72, 0x73},
		.base = 40,
	},
	{
		.data_reg = 0x4f,	/* GP5 */
		.config_regs = {0x3f, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46},
		.base = 50,
	},
	{
		.data_reg = 0x50,	/* GP6 */
		.config_regs = {0x47, 0x48, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59},
		.base = 60,
	},
};

/*
 *	Super-IO functions
 */

static inline int sch311x_sio_enter(int sio_config_port)
{
	/* Don't step on other drivers' I/O space by accident. */
	if (!request_muxed_region(sio_config_port, 2, DRV_NAME)) {
		pr_err(DRV_NAME "I/O address 0x%04x already in use\n",
		       sio_config_port);
		return -EBUSY;
	}

	outb(SIO_CONFIG_KEY_ENTER, sio_config_port);
	return 0;
}

static inline void sch311x_sio_exit(int sio_config_port)
{
	outb(SIO_CONFIG_KEY_EXIT, sio_config_port);
	release_region(sio_config_port, 2);
}

static inline int sch311x_sio_inb(int sio_config_port, int reg)
{
	outb(reg, sio_config_port);
	return inb(sio_config_port + 1);
}

static inline void sch311x_sio_outb(int sio_config_port, int reg, int val)
{
	outb(reg, sio_config_port);
	outb(val, sio_config_port + 1);
}


/*
 *	GPIO functions
 */

static int sch311x_gpio_request(struct gpio_chip *chip, unsigned offset)
{
	struct sch311x_gpio_block *block = gpiochip_get_data(chip);

	if (block->config_regs[offset] == 0) /* GPIO is not available */
		return -ENODEV;

	if (!request_region(block->runtime_reg + block->config_regs[offset],
			    1, DRV_NAME)) {
		dev_err(chip->parent, "Failed to request region 0x%04x.\n",
			block->runtime_reg + block->config_regs[offset]);
		return -EBUSY;
	}
	return 0;
}

static void sch311x_gpio_free(struct gpio_chip *chip, unsigned offset)
{
	struct sch311x_gpio_block *block = gpiochip_get_data(chip);

	if (block->config_regs[offset] == 0) /* GPIO is not available */
		return;

	release_region(block->runtime_reg + block->config_regs[offset], 1);
}

static int sch311x_gpio_get(struct gpio_chip *chip, unsigned offset)
{
	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
	unsigned char data;

	spin_lock(&block->lock);
	data = inb(block->runtime_reg + block->data_reg);
	spin_unlock(&block->lock);

	return !!(data & BIT(offset));
}

static void __sch311x_gpio_set(struct sch311x_gpio_block *block,
			       unsigned offset, int value)
{
	unsigned char data = inb(block->runtime_reg + block->data_reg);
	if (value)
		data |= BIT(offset);
	else
		data &= ~BIT(offset);
	outb(data, block->runtime_reg + block->data_reg);
}

static void sch311x_gpio_set(struct gpio_chip *chip, unsigned offset,
			     int value)
{
	struct sch311x_gpio_block *block = gpiochip_get_data(chip);

	spin_lock(&block->lock);
	 __sch311x_gpio_set(block, offset, value);
	spin_unlock(&block->lock);
}

static int sch311x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
{
	struct sch311x_gpio_block *block = gpiochip_get_data(chip);

	spin_lock(&block->lock);
	outb(SCH311X_GPIO_CONF_IN, block->runtime_reg +
	     block->config_regs[offset]);
	spin_unlock(&block->lock);

	return 0;
}

static int sch311x_gpio_direction_out(struct gpio_chip *chip, unsigned offset,
				      int value)
{
	struct sch311x_gpio_block *block = gpiochip_get_data(chip);

	spin_lock(&block->lock);

	outb(SCH311X_GPIO_CONF_OUT, block->runtime_reg +
	     block->config_regs[offset]);

	__sch311x_gpio_set(block, offset, value);

	spin_unlock(&block->lock);
	return 0;
}

static int sch311x_gpio_probe(struct platform_device *pdev)
{
	struct sch311x_pdev_data *pdata = dev_get_platdata(&pdev->dev);
	struct sch311x_gpio_priv *priv;
	struct sch311x_gpio_block *block;
	int err, i;

	/* we can register all GPIO data registers at once */
	if (!devm_request_region(&pdev->dev, pdata->runtime_reg + GP1, 6,
		DRV_NAME)) {
		dev_err(&pdev->dev, "Failed to request region 0x%04x-0x%04x.\n",
			pdata->runtime_reg + GP1, pdata->runtime_reg + GP1 + 5);
		return -EBUSY;
	}

	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	platform_set_drvdata(pdev, priv);

	for (i = 0; i < ARRAY_SIZE(priv->blocks); i++) {
		block = &priv->blocks[i];

		spin_lock_init(&block->lock);

		block->chip.label = DRV_NAME;
		block->chip.owner = THIS_MODULE;
		block->chip.request = sch311x_gpio_request;
		block->chip.free = sch311x_gpio_free;
		block->chip.direction_input = sch311x_gpio_direction_in;
		block->chip.direction_output = sch311x_gpio_direction_out;
		block->chip.get = sch311x_gpio_get;
		block->chip.set = sch311x_gpio_set;
		block->chip.ngpio = 8;
		block->chip.parent = &pdev->dev;
		block->chip.base = sch311x_gpio_blocks[i].base;
		block->config_regs = sch311x_gpio_blocks[i].config_regs;
		block->data_reg = sch311x_gpio_blocks[i].data_reg;
		block->runtime_reg = pdata->runtime_reg;

		err = gpiochip_add_data(&block->chip, block);
		if (err < 0) {
			dev_err(&pdev->dev,
				"Could not register gpiochip, %d\n", err);
			goto exit_err;
		}
		dev_info(&pdev->dev,
			 "SMSC SCH311x GPIO block %d registered.\n", i);
	}

	return 0;

exit_err:
	/* release already registered chips */
	for (--i; i >= 0; i--)
		gpiochip_remove(&priv->blocks[i].chip);
	return err;
}

static int sch311x_gpio_remove(struct platform_device *pdev)
{
	struct sch311x_gpio_priv *priv = platform_get_drvdata(pdev);
	int i;

	for (i = 0; i < ARRAY_SIZE(priv->blocks); i++) {
		gpiochip_remove(&priv->blocks[i].chip);
		dev_info(&pdev->dev,
			 "SMSC SCH311x GPIO block %d unregistered.\n", i);
	}
	return 0;
}

static struct platform_driver sch311x_gpio_driver = {
	.driver.name	= DRV_NAME,
	.probe		= sch311x_gpio_probe,
	.remove		= sch311x_gpio_remove,
};


/*
 *	Init & exit routines
 */

static int __init sch311x_detect(int sio_config_port, unsigned short *addr)
{
	int err = 0, reg;
	unsigned short base_addr;
	unsigned char dev_id;

	err = sch311x_sio_enter(sio_config_port);
	if (err)
		return err;

	/* Check device ID. */
	reg = sch311x_sio_inb(sio_config_port, 0x20);
	switch (reg) {
	case 0x7c: /* SCH3112 */
		dev_id = 2;
		break;
	case 0x7d: /* SCH3114 */
		dev_id = 4;
		break;
	case 0x7f: /* SCH3116 */
		dev_id = 6;
		break;
	default:
		err = -ENODEV;
		goto exit;
	}

	/* Select logical device A (runtime registers) */
	sch311x_sio_outb(sio_config_port, 0x07, 0x0a);

	/* Check if Logical Device Register is currently active */
	if ((sch311x_sio_inb(sio_config_port, 0x30) & 0x01) == 0)
		pr_info("Seems that LDN 0x0a is not active...\n");

	/* Get the base address of the runtime registers */
	base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) |
			   sch311x_sio_inb(sio_config_port, 0x61);
	if (!base_addr) {
		pr_err("Base address not set\n");
		err = -ENODEV;
		goto exit;
	}
	*addr = base_addr;

	pr_info("Found an SMSC SCH311%d chip at 0x%04x\n", dev_id, base_addr);

exit:
	sch311x_sio_exit(sio_config_port);
	return err;
}

static int __init sch311x_gpio_pdev_add(const unsigned short addr)
{
	struct sch311x_pdev_data pdata;
	int err;

	pdata.runtime_reg = addr;

	sch311x_gpio_pdev = platform_device_alloc(DRV_NAME, -1);
	if (!sch311x_gpio_pdev)
		return -ENOMEM;

	err = platform_device_add_data(sch311x_gpio_pdev,
				       &pdata, sizeof(pdata));
	if (err) {
		pr_err(DRV_NAME "Platform data allocation failed\n");
		goto err;
	}

	err = platform_device_add(sch311x_gpio_pdev);
	if (err) {
		pr_err(DRV_NAME "Device addition failed\n");
		goto err;
	}
	return 0;

err:
	platform_device_put(sch311x_gpio_pdev);
	return err;
}

static int __init sch311x_gpio_init(void)
{
	int err, i;
	unsigned short addr = 0;

	for (i = 0; i < ARRAY_SIZE(sch311x_ioports); i++)
		if (sch311x_detect(sch311x_ioports[i], &addr) == 0)
			break;

	if (!addr)
		return -ENODEV;

	err = platform_driver_register(&sch311x_gpio_driver);
	if (err)
		return err;

	err = sch311x_gpio_pdev_add(addr);
	if (err)
		goto unreg_platform_driver;

	return 0;

unreg_platform_driver:
	platform_driver_unregister(&sch311x_gpio_driver);
	return err;
}

static void __exit sch311x_gpio_exit(void)
{
	platform_device_unregister(sch311x_gpio_pdev);
	platform_driver_unregister(&sch311x_gpio_driver);
}

module_init(sch311x_gpio_init);
module_exit(sch311x_gpio_exit);

MODULE_AUTHOR("Bruno Randolf <br1@einfach.org>");
MODULE_DESCRIPTION("SMSC SCH311x GPIO Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:gpio-sch311x");