xref: /openbmc/linux/drivers/gpio/gpio-sch311x.c (revision 2fa49589)
1 /*
2  * GPIO driver for the SMSC SCH311x Super-I/O chips
3  *
4  * Copyright (C) 2013 Bruno Randolf <br1@einfach.org>
5  *
6  * SuperIO functions and chip detection:
7  * (c) Copyright 2008 Wim Van Sebroeck <wim@iguana.be>.
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  */
14 
15 #include <linux/ioport.h>
16 #include <linux/module.h>
17 #include <linux/kernel.h>
18 #include <linux/init.h>
19 #include <linux/platform_device.h>
20 #include <linux/gpio/driver.h>
21 #include <linux/bitops.h>
22 #include <linux/io.h>
23 
24 #define DRV_NAME			"gpio-sch311x"
25 
26 #define SCH311X_GPIO_CONF_DIR		BIT(0)
27 #define SCH311X_GPIO_CONF_INVERT	BIT(1)
28 #define SCH311X_GPIO_CONF_OPEN_DRAIN	BIT(7)
29 
30 #define SIO_CONFIG_KEY_ENTER		0x55
31 #define SIO_CONFIG_KEY_EXIT		0xaa
32 
33 #define GP1				0x4b
34 
35 static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e };
36 
37 static struct platform_device *sch311x_gpio_pdev;
38 
39 struct sch311x_pdev_data {		/* platform device data */
40 	unsigned short runtime_reg;	/* runtime register base address */
41 };
42 
43 struct sch311x_gpio_block {		/* one GPIO block runtime data */
44 	struct gpio_chip chip;
45 	unsigned short data_reg;	/* from definition below */
46 	unsigned short *config_regs;	/* pointer to definition below */
47 	unsigned short runtime_reg;	/* runtime register */
48 	spinlock_t lock;		/* lock for this GPIO block */
49 };
50 
51 struct sch311x_gpio_priv {		/* driver private data */
52 	struct sch311x_gpio_block blocks[6];
53 };
54 
55 struct sch311x_gpio_block_def {		/* register address definitions */
56 	unsigned short data_reg;
57 	unsigned short config_regs[8];
58 	unsigned short base;
59 };
60 
61 /* Note: some GPIOs are not available, these are marked with 0x00 */
62 
63 static struct sch311x_gpio_block_def sch311x_gpio_blocks[] = {
64 	{
65 		.data_reg = 0x4b,	/* GP1 */
66 		.config_regs = {0x23, 0x24, 0x25, 0x26, 0x27, 0x29, 0x2a, 0x2b},
67 		.base = 10,
68 	},
69 	{
70 		.data_reg = 0x4c,	/* GP2 */
71 		.config_regs = {0x00, 0x2c, 0x2d, 0x00, 0x00, 0x00, 0x00, 0x32},
72 		.base = 20,
73 	},
74 	{
75 		.data_reg = 0x4d,	/* GP3 */
76 		.config_regs = {0x33, 0x34, 0x35, 0x36, 0x37, 0x00, 0x39, 0x3a},
77 		.base = 30,
78 	},
79 	{
80 		.data_reg = 0x4e,	/* GP4 */
81 		.config_regs = {0x3b, 0x00, 0x3d, 0x00, 0x6e, 0x6f, 0x72, 0x73},
82 		.base = 40,
83 	},
84 	{
85 		.data_reg = 0x4f,	/* GP5 */
86 		.config_regs = {0x3f, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46},
87 		.base = 50,
88 	},
89 	{
90 		.data_reg = 0x50,	/* GP6 */
91 		.config_regs = {0x47, 0x48, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59},
92 		.base = 60,
93 	},
94 };
95 
96 /*
97  *	Super-IO functions
98  */
99 
100 static inline int sch311x_sio_enter(int sio_config_port)
101 {
102 	/* Don't step on other drivers' I/O space by accident. */
103 	if (!request_muxed_region(sio_config_port, 2, DRV_NAME)) {
104 		pr_err(DRV_NAME "I/O address 0x%04x already in use\n",
105 		       sio_config_port);
106 		return -EBUSY;
107 	}
108 
109 	outb(SIO_CONFIG_KEY_ENTER, sio_config_port);
110 	return 0;
111 }
112 
113 static inline void sch311x_sio_exit(int sio_config_port)
114 {
115 	outb(SIO_CONFIG_KEY_EXIT, sio_config_port);
116 	release_region(sio_config_port, 2);
117 }
118 
119 static inline int sch311x_sio_inb(int sio_config_port, int reg)
120 {
121 	outb(reg, sio_config_port);
122 	return inb(sio_config_port + 1);
123 }
124 
125 static inline void sch311x_sio_outb(int sio_config_port, int reg, int val)
126 {
127 	outb(reg, sio_config_port);
128 	outb(val, sio_config_port + 1);
129 }
130 
131 
132 /*
133  *	GPIO functions
134  */
135 
136 static int sch311x_gpio_request(struct gpio_chip *chip, unsigned offset)
137 {
138 	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
139 
140 	if (block->config_regs[offset] == 0) /* GPIO is not available */
141 		return -ENODEV;
142 
143 	if (!request_region(block->runtime_reg + block->config_regs[offset],
144 			    1, DRV_NAME)) {
145 		dev_err(chip->parent, "Failed to request region 0x%04x.\n",
146 			block->runtime_reg + block->config_regs[offset]);
147 		return -EBUSY;
148 	}
149 	return 0;
150 }
151 
152 static void sch311x_gpio_free(struct gpio_chip *chip, unsigned offset)
153 {
154 	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
155 
156 	if (block->config_regs[offset] == 0) /* GPIO is not available */
157 		return;
158 
159 	release_region(block->runtime_reg + block->config_regs[offset], 1);
160 }
161 
162 static int sch311x_gpio_get(struct gpio_chip *chip, unsigned offset)
163 {
164 	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
165 	u8 data;
166 
167 	spin_lock(&block->lock);
168 	data = inb(block->runtime_reg + block->data_reg);
169 	spin_unlock(&block->lock);
170 
171 	return !!(data & BIT(offset));
172 }
173 
174 static void __sch311x_gpio_set(struct sch311x_gpio_block *block,
175 			       unsigned offset, int value)
176 {
177 	u8 data = inb(block->runtime_reg + block->data_reg);
178 	if (value)
179 		data |= BIT(offset);
180 	else
181 		data &= ~BIT(offset);
182 	outb(data, block->runtime_reg + block->data_reg);
183 }
184 
185 static void sch311x_gpio_set(struct gpio_chip *chip, unsigned offset,
186 			     int value)
187 {
188 	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
189 
190 	spin_lock(&block->lock);
191 	__sch311x_gpio_set(block, offset, value);
192 	spin_unlock(&block->lock);
193 }
194 
195 static int sch311x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
196 {
197 	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
198 	u8 data;
199 
200 	spin_lock(&block->lock);
201 	data = inb(block->runtime_reg + block->config_regs[offset]);
202 	data |= SCH311X_GPIO_CONF_DIR;
203 	outb(data, block->runtime_reg + block->config_regs[offset]);
204 	spin_unlock(&block->lock);
205 
206 	return 0;
207 }
208 
209 static int sch311x_gpio_direction_out(struct gpio_chip *chip, unsigned offset,
210 				      int value)
211 {
212 	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
213 	u8 data;
214 
215 	spin_lock(&block->lock);
216 
217 	data = inb(block->runtime_reg + block->config_regs[offset]);
218 	data &= ~SCH311X_GPIO_CONF_DIR;
219 	outb(data, block->runtime_reg + block->config_regs[offset]);
220 	__sch311x_gpio_set(block, offset, value);
221 
222 	spin_unlock(&block->lock);
223 	return 0;
224 }
225 
226 static int sch311x_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
227 {
228 	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
229 	u8 data;
230 
231 	spin_lock(&block->lock);
232 	data = inb(block->runtime_reg + block->config_regs[offset]);
233 	spin_unlock(&block->lock);
234 
235 	return !!(data & SCH311X_GPIO_CONF_DIR);
236 }
237 
238 static int sch311x_gpio_set_config(struct gpio_chip *chip, unsigned offset,
239 				   unsigned long config)
240 {
241 	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
242 	enum pin_config_param param = pinconf_to_config_param(config);
243 	u8 data;
244 
245 	switch (param) {
246 	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
247 		spin_lock(&block->lock);
248 		data = inb(block->runtime_reg + block->config_regs[offset]);
249 		data |= SCH311X_GPIO_CONF_OPEN_DRAIN;
250 		outb(data, block->runtime_reg + block->config_regs[offset]);
251 		spin_unlock(&block->lock);
252 		return 0;
253 	case PIN_CONFIG_DRIVE_PUSH_PULL:
254 		spin_lock(&block->lock);
255 		data = inb(block->runtime_reg + block->config_regs[offset]);
256 		data &= ~SCH311X_GPIO_CONF_OPEN_DRAIN;
257 		outb(data, block->runtime_reg + block->config_regs[offset]);
258 		spin_unlock(&block->lock);
259 		return 0;
260 	default:
261 		break;
262 	}
263 	return -ENOTSUPP;
264 }
265 
266 static int sch311x_gpio_probe(struct platform_device *pdev)
267 {
268 	struct sch311x_pdev_data *pdata = dev_get_platdata(&pdev->dev);
269 	struct sch311x_gpio_priv *priv;
270 	struct sch311x_gpio_block *block;
271 	int err, i;
272 
273 	/* we can register all GPIO data registers at once */
274 	if (!devm_request_region(&pdev->dev, pdata->runtime_reg + GP1, 6,
275 		DRV_NAME)) {
276 		dev_err(&pdev->dev, "Failed to request region 0x%04x-0x%04x.\n",
277 			pdata->runtime_reg + GP1, pdata->runtime_reg + GP1 + 5);
278 		return -EBUSY;
279 	}
280 
281 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
282 	if (!priv)
283 		return -ENOMEM;
284 
285 	platform_set_drvdata(pdev, priv);
286 
287 	for (i = 0; i < ARRAY_SIZE(priv->blocks); i++) {
288 		block = &priv->blocks[i];
289 
290 		spin_lock_init(&block->lock);
291 
292 		block->chip.label = DRV_NAME;
293 		block->chip.owner = THIS_MODULE;
294 		block->chip.request = sch311x_gpio_request;
295 		block->chip.free = sch311x_gpio_free;
296 		block->chip.direction_input = sch311x_gpio_direction_in;
297 		block->chip.direction_output = sch311x_gpio_direction_out;
298 		block->chip.get_direction = sch311x_gpio_get_direction;
299 		block->chip.set_config = sch311x_gpio_set_config;
300 		block->chip.get = sch311x_gpio_get;
301 		block->chip.set = sch311x_gpio_set;
302 		block->chip.ngpio = 8;
303 		block->chip.parent = &pdev->dev;
304 		block->chip.base = sch311x_gpio_blocks[i].base;
305 		block->config_regs = sch311x_gpio_blocks[i].config_regs;
306 		block->data_reg = sch311x_gpio_blocks[i].data_reg;
307 		block->runtime_reg = pdata->runtime_reg;
308 
309 		err = gpiochip_add_data(&block->chip, block);
310 		if (err < 0) {
311 			dev_err(&pdev->dev,
312 				"Could not register gpiochip, %d\n", err);
313 			goto exit_err;
314 		}
315 		dev_info(&pdev->dev,
316 			 "SMSC SCH311x GPIO block %d registered.\n", i);
317 	}
318 
319 	return 0;
320 
321 exit_err:
322 	/* release already registered chips */
323 	for (--i; i >= 0; i--)
324 		gpiochip_remove(&priv->blocks[i].chip);
325 	return err;
326 }
327 
328 static int sch311x_gpio_remove(struct platform_device *pdev)
329 {
330 	struct sch311x_gpio_priv *priv = platform_get_drvdata(pdev);
331 	int i;
332 
333 	for (i = 0; i < ARRAY_SIZE(priv->blocks); i++) {
334 		gpiochip_remove(&priv->blocks[i].chip);
335 		dev_info(&pdev->dev,
336 			 "SMSC SCH311x GPIO block %d unregistered.\n", i);
337 	}
338 	return 0;
339 }
340 
341 static struct platform_driver sch311x_gpio_driver = {
342 	.driver.name	= DRV_NAME,
343 	.probe		= sch311x_gpio_probe,
344 	.remove		= sch311x_gpio_remove,
345 };
346 
347 
348 /*
349  *	Init & exit routines
350  */
351 
352 static int __init sch311x_detect(int sio_config_port, unsigned short *addr)
353 {
354 	int err = 0, reg;
355 	unsigned short base_addr;
356 	u8 dev_id;
357 
358 	err = sch311x_sio_enter(sio_config_port);
359 	if (err)
360 		return err;
361 
362 	/* Check device ID. */
363 	reg = sch311x_sio_inb(sio_config_port, 0x20);
364 	switch (reg) {
365 	case 0x7c: /* SCH3112 */
366 		dev_id = 2;
367 		break;
368 	case 0x7d: /* SCH3114 */
369 		dev_id = 4;
370 		break;
371 	case 0x7f: /* SCH3116 */
372 		dev_id = 6;
373 		break;
374 	default:
375 		err = -ENODEV;
376 		goto exit;
377 	}
378 
379 	/* Select logical device A (runtime registers) */
380 	sch311x_sio_outb(sio_config_port, 0x07, 0x0a);
381 
382 	/* Check if Logical Device Register is currently active */
383 	if ((sch311x_sio_inb(sio_config_port, 0x30) & 0x01) == 0)
384 		pr_info("Seems that LDN 0x0a is not active...\n");
385 
386 	/* Get the base address of the runtime registers */
387 	base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) |
388 			   sch311x_sio_inb(sio_config_port, 0x61);
389 	if (!base_addr) {
390 		pr_err("Base address not set\n");
391 		err = -ENODEV;
392 		goto exit;
393 	}
394 	*addr = base_addr;
395 
396 	pr_info("Found an SMSC SCH311%d chip at 0x%04x\n", dev_id, base_addr);
397 
398 exit:
399 	sch311x_sio_exit(sio_config_port);
400 	return err;
401 }
402 
403 static int __init sch311x_gpio_pdev_add(const unsigned short addr)
404 {
405 	struct sch311x_pdev_data pdata;
406 	int err;
407 
408 	pdata.runtime_reg = addr;
409 
410 	sch311x_gpio_pdev = platform_device_alloc(DRV_NAME, -1);
411 	if (!sch311x_gpio_pdev)
412 		return -ENOMEM;
413 
414 	err = platform_device_add_data(sch311x_gpio_pdev,
415 				       &pdata, sizeof(pdata));
416 	if (err) {
417 		pr_err(DRV_NAME "Platform data allocation failed\n");
418 		goto err;
419 	}
420 
421 	err = platform_device_add(sch311x_gpio_pdev);
422 	if (err) {
423 		pr_err(DRV_NAME "Device addition failed\n");
424 		goto err;
425 	}
426 	return 0;
427 
428 err:
429 	platform_device_put(sch311x_gpio_pdev);
430 	return err;
431 }
432 
433 static int __init sch311x_gpio_init(void)
434 {
435 	int err, i;
436 	unsigned short addr = 0;
437 
438 	for (i = 0; i < ARRAY_SIZE(sch311x_ioports); i++)
439 		if (sch311x_detect(sch311x_ioports[i], &addr) == 0)
440 			break;
441 
442 	if (!addr)
443 		return -ENODEV;
444 
445 	err = platform_driver_register(&sch311x_gpio_driver);
446 	if (err)
447 		return err;
448 
449 	err = sch311x_gpio_pdev_add(addr);
450 	if (err)
451 		goto unreg_platform_driver;
452 
453 	return 0;
454 
455 unreg_platform_driver:
456 	platform_driver_unregister(&sch311x_gpio_driver);
457 	return err;
458 }
459 
460 static void __exit sch311x_gpio_exit(void)
461 {
462 	platform_device_unregister(sch311x_gpio_pdev);
463 	platform_driver_unregister(&sch311x_gpio_driver);
464 }
465 
466 module_init(sch311x_gpio_init);
467 module_exit(sch311x_gpio_exit);
468 
469 MODULE_AUTHOR("Bruno Randolf <br1@einfach.org>");
470 MODULE_DESCRIPTION("SMSC SCH311x GPIO Driver");
471 MODULE_LICENSE("GPL");
472 MODULE_ALIAS("platform:gpio-sch311x");
473