xref: /openbmc/linux/drivers/gpio/gpio-sch311x.c (revision fb574682)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * GPIO driver for the SMSC SCH311x Super-I/O chips
4  *
5  * Copyright (C) 2013 Bruno Randolf <br1@einfach.org>
6  *
7  * SuperIO functions and chip detection:
8  * (c) Copyright 2008 Wim Van Sebroeck <wim@iguana.be>.
9  */
10 
11 #include <linux/ioport.h>
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/platform_device.h>
16 #include <linux/gpio/driver.h>
17 #include <linux/bitops.h>
18 #include <linux/io.h>
19 
20 #define DRV_NAME			"gpio-sch311x"
21 
22 #define SCH311X_GPIO_CONF_DIR		BIT(0)
23 #define SCH311X_GPIO_CONF_INVERT	BIT(1)
24 #define SCH311X_GPIO_CONF_OPEN_DRAIN	BIT(7)
25 
26 #define SIO_CONFIG_KEY_ENTER		0x55
27 #define SIO_CONFIG_KEY_EXIT		0xaa
28 
29 #define GP1				0x4b
30 
31 static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e };
32 
33 static struct platform_device *sch311x_gpio_pdev;
34 
35 struct sch311x_pdev_data {		/* platform device data */
36 	unsigned short runtime_reg;	/* runtime register base address */
37 };
38 
39 struct sch311x_gpio_block {		/* one GPIO block runtime data */
40 	struct gpio_chip chip;
41 	unsigned short data_reg;	/* from definition below */
42 	unsigned short *config_regs;	/* pointer to definition below */
43 	unsigned short runtime_reg;	/* runtime register */
44 	spinlock_t lock;		/* lock for this GPIO block */
45 };
46 
47 struct sch311x_gpio_priv {		/* driver private data */
48 	struct sch311x_gpio_block blocks[6];
49 };
50 
51 struct sch311x_gpio_block_def {		/* register address definitions */
52 	unsigned short data_reg;
53 	unsigned short config_regs[8];
54 	unsigned short base;
55 };
56 
57 /* Note: some GPIOs are not available, these are marked with 0x00 */
58 
59 static struct sch311x_gpio_block_def sch311x_gpio_blocks[] = {
60 	{
61 		.data_reg = 0x4b,	/* GP1 */
62 		.config_regs = {0x23, 0x24, 0x25, 0x26, 0x27, 0x29, 0x2a, 0x2b},
63 		.base = 10,
64 	},
65 	{
66 		.data_reg = 0x4c,	/* GP2 */
67 		.config_regs = {0x00, 0x2c, 0x2d, 0x00, 0x00, 0x00, 0x00, 0x32},
68 		.base = 20,
69 	},
70 	{
71 		.data_reg = 0x4d,	/* GP3 */
72 		.config_regs = {0x33, 0x34, 0x35, 0x36, 0x37, 0x00, 0x39, 0x3a},
73 		.base = 30,
74 	},
75 	{
76 		.data_reg = 0x4e,	/* GP4 */
77 		.config_regs = {0x3b, 0x00, 0x3d, 0x00, 0x6e, 0x6f, 0x72, 0x73},
78 		.base = 40,
79 	},
80 	{
81 		.data_reg = 0x4f,	/* GP5 */
82 		.config_regs = {0x3f, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46},
83 		.base = 50,
84 	},
85 	{
86 		.data_reg = 0x50,	/* GP6 */
87 		.config_regs = {0x47, 0x48, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59},
88 		.base = 60,
89 	},
90 };
91 
92 /*
93  *	Super-IO functions
94  */
95 
96 static inline int sch311x_sio_enter(int sio_config_port)
97 {
98 	/* Don't step on other drivers' I/O space by accident. */
99 	if (!request_muxed_region(sio_config_port, 2, DRV_NAME)) {
100 		pr_err(DRV_NAME "I/O address 0x%04x already in use\n",
101 		       sio_config_port);
102 		return -EBUSY;
103 	}
104 
105 	outb(SIO_CONFIG_KEY_ENTER, sio_config_port);
106 	return 0;
107 }
108 
109 static inline void sch311x_sio_exit(int sio_config_port)
110 {
111 	outb(SIO_CONFIG_KEY_EXIT, sio_config_port);
112 	release_region(sio_config_port, 2);
113 }
114 
115 static inline int sch311x_sio_inb(int sio_config_port, int reg)
116 {
117 	outb(reg, sio_config_port);
118 	return inb(sio_config_port + 1);
119 }
120 
121 static inline void sch311x_sio_outb(int sio_config_port, int reg, int val)
122 {
123 	outb(reg, sio_config_port);
124 	outb(val, sio_config_port + 1);
125 }
126 
127 
128 /*
129  *	GPIO functions
130  */
131 
132 static int sch311x_gpio_request(struct gpio_chip *chip, unsigned offset)
133 {
134 	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
135 
136 	if (block->config_regs[offset] == 0) /* GPIO is not available */
137 		return -ENODEV;
138 
139 	if (!request_region(block->runtime_reg + block->config_regs[offset],
140 			    1, DRV_NAME)) {
141 		dev_err(chip->parent, "Failed to request region 0x%04x.\n",
142 			block->runtime_reg + block->config_regs[offset]);
143 		return -EBUSY;
144 	}
145 	return 0;
146 }
147 
148 static void sch311x_gpio_free(struct gpio_chip *chip, unsigned offset)
149 {
150 	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
151 
152 	if (block->config_regs[offset] == 0) /* GPIO is not available */
153 		return;
154 
155 	release_region(block->runtime_reg + block->config_regs[offset], 1);
156 }
157 
158 static int sch311x_gpio_get(struct gpio_chip *chip, unsigned offset)
159 {
160 	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
161 	u8 data;
162 
163 	spin_lock(&block->lock);
164 	data = inb(block->runtime_reg + block->data_reg);
165 	spin_unlock(&block->lock);
166 
167 	return !!(data & BIT(offset));
168 }
169 
170 static void __sch311x_gpio_set(struct sch311x_gpio_block *block,
171 			       unsigned offset, int value)
172 {
173 	u8 data = inb(block->runtime_reg + block->data_reg);
174 	if (value)
175 		data |= BIT(offset);
176 	else
177 		data &= ~BIT(offset);
178 	outb(data, block->runtime_reg + block->data_reg);
179 }
180 
181 static void sch311x_gpio_set(struct gpio_chip *chip, unsigned offset,
182 			     int value)
183 {
184 	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
185 
186 	spin_lock(&block->lock);
187 	__sch311x_gpio_set(block, offset, value);
188 	spin_unlock(&block->lock);
189 }
190 
191 static int sch311x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
192 {
193 	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
194 	u8 data;
195 
196 	spin_lock(&block->lock);
197 	data = inb(block->runtime_reg + block->config_regs[offset]);
198 	data |= SCH311X_GPIO_CONF_DIR;
199 	outb(data, block->runtime_reg + block->config_regs[offset]);
200 	spin_unlock(&block->lock);
201 
202 	return 0;
203 }
204 
205 static int sch311x_gpio_direction_out(struct gpio_chip *chip, unsigned offset,
206 				      int value)
207 {
208 	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
209 	u8 data;
210 
211 	spin_lock(&block->lock);
212 
213 	data = inb(block->runtime_reg + block->config_regs[offset]);
214 	data &= ~SCH311X_GPIO_CONF_DIR;
215 	outb(data, block->runtime_reg + block->config_regs[offset]);
216 	__sch311x_gpio_set(block, offset, value);
217 
218 	spin_unlock(&block->lock);
219 	return 0;
220 }
221 
222 static int sch311x_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
223 {
224 	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
225 	u8 data;
226 
227 	spin_lock(&block->lock);
228 	data = inb(block->runtime_reg + block->config_regs[offset]);
229 	spin_unlock(&block->lock);
230 
231 	if (data & SCH311X_GPIO_CONF_DIR)
232 		return GPIO_LINE_DIRECTION_IN;
233 
234 	return GPIO_LINE_DIRECTION_OUT;
235 }
236 
237 static int sch311x_gpio_set_config(struct gpio_chip *chip, unsigned offset,
238 				   unsigned long config)
239 {
240 	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
241 	enum pin_config_param param = pinconf_to_config_param(config);
242 	u8 data;
243 
244 	switch (param) {
245 	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
246 		spin_lock(&block->lock);
247 		data = inb(block->runtime_reg + block->config_regs[offset]);
248 		data |= SCH311X_GPIO_CONF_OPEN_DRAIN;
249 		outb(data, block->runtime_reg + block->config_regs[offset]);
250 		spin_unlock(&block->lock);
251 		return 0;
252 	case PIN_CONFIG_DRIVE_PUSH_PULL:
253 		spin_lock(&block->lock);
254 		data = inb(block->runtime_reg + block->config_regs[offset]);
255 		data &= ~SCH311X_GPIO_CONF_OPEN_DRAIN;
256 		outb(data, block->runtime_reg + block->config_regs[offset]);
257 		spin_unlock(&block->lock);
258 		return 0;
259 	default:
260 		break;
261 	}
262 	return -ENOTSUPP;
263 }
264 
265 static int sch311x_gpio_probe(struct platform_device *pdev)
266 {
267 	struct sch311x_pdev_data *pdata = dev_get_platdata(&pdev->dev);
268 	struct sch311x_gpio_priv *priv;
269 	struct sch311x_gpio_block *block;
270 	int err, i;
271 
272 	/* we can register all GPIO data registers at once */
273 	if (!devm_request_region(&pdev->dev, pdata->runtime_reg + GP1, 6,
274 		DRV_NAME)) {
275 		dev_err(&pdev->dev, "Failed to request region 0x%04x-0x%04x.\n",
276 			pdata->runtime_reg + GP1, pdata->runtime_reg + GP1 + 5);
277 		return -EBUSY;
278 	}
279 
280 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
281 	if (!priv)
282 		return -ENOMEM;
283 
284 	platform_set_drvdata(pdev, priv);
285 
286 	for (i = 0; i < ARRAY_SIZE(priv->blocks); i++) {
287 		block = &priv->blocks[i];
288 
289 		spin_lock_init(&block->lock);
290 
291 		block->chip.label = DRV_NAME;
292 		block->chip.owner = THIS_MODULE;
293 		block->chip.request = sch311x_gpio_request;
294 		block->chip.free = sch311x_gpio_free;
295 		block->chip.direction_input = sch311x_gpio_direction_in;
296 		block->chip.direction_output = sch311x_gpio_direction_out;
297 		block->chip.get_direction = sch311x_gpio_get_direction;
298 		block->chip.set_config = sch311x_gpio_set_config;
299 		block->chip.get = sch311x_gpio_get;
300 		block->chip.set = sch311x_gpio_set;
301 		block->chip.ngpio = 8;
302 		block->chip.parent = &pdev->dev;
303 		block->chip.base = sch311x_gpio_blocks[i].base;
304 		block->config_regs = sch311x_gpio_blocks[i].config_regs;
305 		block->data_reg = sch311x_gpio_blocks[i].data_reg;
306 		block->runtime_reg = pdata->runtime_reg;
307 
308 		err = gpiochip_add_data(&block->chip, block);
309 		if (err < 0) {
310 			dev_err(&pdev->dev,
311 				"Could not register gpiochip, %d\n", err);
312 			goto exit_err;
313 		}
314 		dev_info(&pdev->dev,
315 			 "SMSC SCH311x GPIO block %d registered.\n", i);
316 	}
317 
318 	return 0;
319 
320 exit_err:
321 	/* release already registered chips */
322 	for (--i; i >= 0; i--)
323 		gpiochip_remove(&priv->blocks[i].chip);
324 	return err;
325 }
326 
327 static int sch311x_gpio_remove(struct platform_device *pdev)
328 {
329 	struct sch311x_gpio_priv *priv = platform_get_drvdata(pdev);
330 	int i;
331 
332 	for (i = 0; i < ARRAY_SIZE(priv->blocks); i++) {
333 		gpiochip_remove(&priv->blocks[i].chip);
334 		dev_info(&pdev->dev,
335 			 "SMSC SCH311x GPIO block %d unregistered.\n", i);
336 	}
337 	return 0;
338 }
339 
340 static struct platform_driver sch311x_gpio_driver = {
341 	.driver.name	= DRV_NAME,
342 	.probe		= sch311x_gpio_probe,
343 	.remove		= sch311x_gpio_remove,
344 };
345 
346 
347 /*
348  *	Init & exit routines
349  */
350 
351 static int __init sch311x_detect(int sio_config_port, unsigned short *addr)
352 {
353 	int err = 0, reg;
354 	unsigned short base_addr;
355 	u8 dev_id;
356 
357 	err = sch311x_sio_enter(sio_config_port);
358 	if (err)
359 		return err;
360 
361 	/* Check device ID. */
362 	reg = sch311x_sio_inb(sio_config_port, 0x20);
363 	switch (reg) {
364 	case 0x7c: /* SCH3112 */
365 		dev_id = 2;
366 		break;
367 	case 0x7d: /* SCH3114 */
368 		dev_id = 4;
369 		break;
370 	case 0x7f: /* SCH3116 */
371 		dev_id = 6;
372 		break;
373 	default:
374 		err = -ENODEV;
375 		goto exit;
376 	}
377 
378 	/* Select logical device A (runtime registers) */
379 	sch311x_sio_outb(sio_config_port, 0x07, 0x0a);
380 
381 	/* Check if Logical Device Register is currently active */
382 	if ((sch311x_sio_inb(sio_config_port, 0x30) & 0x01) == 0)
383 		pr_info("Seems that LDN 0x0a is not active...\n");
384 
385 	/* Get the base address of the runtime registers */
386 	base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) |
387 			   sch311x_sio_inb(sio_config_port, 0x61);
388 	if (!base_addr) {
389 		pr_err("Base address not set\n");
390 		err = -ENODEV;
391 		goto exit;
392 	}
393 	*addr = base_addr;
394 
395 	pr_info("Found an SMSC SCH311%d chip at 0x%04x\n", dev_id, base_addr);
396 
397 exit:
398 	sch311x_sio_exit(sio_config_port);
399 	return err;
400 }
401 
402 static int __init sch311x_gpio_pdev_add(const unsigned short addr)
403 {
404 	struct sch311x_pdev_data pdata;
405 	int err;
406 
407 	pdata.runtime_reg = addr;
408 
409 	sch311x_gpio_pdev = platform_device_alloc(DRV_NAME, -1);
410 	if (!sch311x_gpio_pdev)
411 		return -ENOMEM;
412 
413 	err = platform_device_add_data(sch311x_gpio_pdev,
414 				       &pdata, sizeof(pdata));
415 	if (err) {
416 		pr_err(DRV_NAME "Platform data allocation failed\n");
417 		goto err;
418 	}
419 
420 	err = platform_device_add(sch311x_gpio_pdev);
421 	if (err) {
422 		pr_err(DRV_NAME "Device addition failed\n");
423 		goto err;
424 	}
425 	return 0;
426 
427 err:
428 	platform_device_put(sch311x_gpio_pdev);
429 	return err;
430 }
431 
432 static int __init sch311x_gpio_init(void)
433 {
434 	int err, i;
435 	unsigned short addr = 0;
436 
437 	for (i = 0; i < ARRAY_SIZE(sch311x_ioports); i++)
438 		if (sch311x_detect(sch311x_ioports[i], &addr) == 0)
439 			break;
440 
441 	if (!addr)
442 		return -ENODEV;
443 
444 	err = platform_driver_register(&sch311x_gpio_driver);
445 	if (err)
446 		return err;
447 
448 	err = sch311x_gpio_pdev_add(addr);
449 	if (err)
450 		goto unreg_platform_driver;
451 
452 	return 0;
453 
454 unreg_platform_driver:
455 	platform_driver_unregister(&sch311x_gpio_driver);
456 	return err;
457 }
458 
459 static void __exit sch311x_gpio_exit(void)
460 {
461 	platform_device_unregister(sch311x_gpio_pdev);
462 	platform_driver_unregister(&sch311x_gpio_driver);
463 }
464 
465 module_init(sch311x_gpio_init);
466 module_exit(sch311x_gpio_exit);
467 
468 MODULE_AUTHOR("Bruno Randolf <br1@einfach.org>");
469 MODULE_DESCRIPTION("SMSC SCH311x GPIO Driver");
470 MODULE_LICENSE("GPL");
471 MODULE_ALIAS("platform:gpio-sch311x");
472