xref: /openbmc/linux/drivers/gpio/gpio-sch311x.c (revision a8fe58ce)
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/module.h>
16 #include <linux/kernel.h>
17 #include <linux/init.h>
18 #include <linux/platform_device.h>
19 #include <linux/gpio.h>
20 #include <linux/bitops.h>
21 #include <linux/io.h>
22 
23 #define DRV_NAME			"gpio-sch311x"
24 
25 #define SCH311X_GPIO_CONF_OUT		0x00
26 #define SCH311X_GPIO_CONF_IN		0x01
27 #define SCH311X_GPIO_CONF_INVERT	0x02
28 #define SCH311X_GPIO_CONF_OPEN_DRAIN	0x80
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 	unsigned char 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 	unsigned char 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 
199 	spin_lock(&block->lock);
200 	outb(SCH311X_GPIO_CONF_IN, block->runtime_reg +
201 	     block->config_regs[offset]);
202 	spin_unlock(&block->lock);
203 
204 	return 0;
205 }
206 
207 static int sch311x_gpio_direction_out(struct gpio_chip *chip, unsigned offset,
208 				      int value)
209 {
210 	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
211 
212 	spin_lock(&block->lock);
213 
214 	outb(SCH311X_GPIO_CONF_OUT, block->runtime_reg +
215 	     block->config_regs[offset]);
216 
217 	__sch311x_gpio_set(block, offset, value);
218 
219 	spin_unlock(&block->lock);
220 	return 0;
221 }
222 
223 static int sch311x_gpio_probe(struct platform_device *pdev)
224 {
225 	struct sch311x_pdev_data *pdata = dev_get_platdata(&pdev->dev);
226 	struct sch311x_gpio_priv *priv;
227 	struct sch311x_gpio_block *block;
228 	int err, i;
229 
230 	/* we can register all GPIO data registers at once */
231 	if (!request_region(pdata->runtime_reg + GP1, 6, DRV_NAME)) {
232 		dev_err(&pdev->dev, "Failed to request region 0x%04x-0x%04x.\n",
233 			pdata->runtime_reg + GP1, pdata->runtime_reg + GP1 + 5);
234 		return -EBUSY;
235 	}
236 
237 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
238 	if (!priv)
239 		return -ENOMEM;
240 
241 	platform_set_drvdata(pdev, priv);
242 
243 	for (i = 0; i < ARRAY_SIZE(priv->blocks); i++) {
244 		block = &priv->blocks[i];
245 
246 		spin_lock_init(&block->lock);
247 
248 		block->chip.label = DRV_NAME;
249 		block->chip.owner = THIS_MODULE;
250 		block->chip.request = sch311x_gpio_request;
251 		block->chip.free = sch311x_gpio_free;
252 		block->chip.direction_input = sch311x_gpio_direction_in;
253 		block->chip.direction_output = sch311x_gpio_direction_out;
254 		block->chip.get = sch311x_gpio_get;
255 		block->chip.set = sch311x_gpio_set;
256 		block->chip.ngpio = 8;
257 		block->chip.parent = &pdev->dev;
258 		block->chip.base = sch311x_gpio_blocks[i].base;
259 		block->config_regs = sch311x_gpio_blocks[i].config_regs;
260 		block->data_reg = sch311x_gpio_blocks[i].data_reg;
261 		block->runtime_reg = pdata->runtime_reg;
262 
263 		err = gpiochip_add_data(&block->chip, block);
264 		if (err < 0) {
265 			dev_err(&pdev->dev,
266 				"Could not register gpiochip, %d\n", err);
267 			goto exit_err;
268 		}
269 		dev_info(&pdev->dev,
270 			 "SMSC SCH311x GPIO block %d registered.\n", i);
271 	}
272 
273 	return 0;
274 
275 exit_err:
276 	release_region(pdata->runtime_reg + GP1, 6);
277 	/* release already registered chips */
278 	for (--i; i >= 0; i--)
279 		gpiochip_remove(&priv->blocks[i].chip);
280 	return err;
281 }
282 
283 static int sch311x_gpio_remove(struct platform_device *pdev)
284 {
285 	struct sch311x_pdev_data *pdata = dev_get_platdata(&pdev->dev);
286 	struct sch311x_gpio_priv *priv = platform_get_drvdata(pdev);
287 	int i;
288 
289 	release_region(pdata->runtime_reg + GP1, 6);
290 
291 	for (i = 0; i < ARRAY_SIZE(priv->blocks); i++) {
292 		gpiochip_remove(&priv->blocks[i].chip);
293 		dev_info(&pdev->dev,
294 			 "SMSC SCH311x GPIO block %d unregistered.\n", i);
295 	}
296 	return 0;
297 }
298 
299 static struct platform_driver sch311x_gpio_driver = {
300 	.driver.name	= DRV_NAME,
301 	.driver.owner	= THIS_MODULE,
302 	.probe		= sch311x_gpio_probe,
303 	.remove		= sch311x_gpio_remove,
304 };
305 
306 
307 /*
308  *	Init & exit routines
309  */
310 
311 static int __init sch311x_detect(int sio_config_port, unsigned short *addr)
312 {
313 	int err = 0, reg;
314 	unsigned short base_addr;
315 	unsigned char dev_id;
316 
317 	err = sch311x_sio_enter(sio_config_port);
318 	if (err)
319 		return err;
320 
321 	/* Check device ID. */
322 	reg = sch311x_sio_inb(sio_config_port, 0x20);
323 	switch (reg) {
324 	case 0x7c: /* SCH3112 */
325 		dev_id = 2;
326 		break;
327 	case 0x7d: /* SCH3114 */
328 		dev_id = 4;
329 		break;
330 	case 0x7f: /* SCH3116 */
331 		dev_id = 6;
332 		break;
333 	default:
334 		err = -ENODEV;
335 		goto exit;
336 	}
337 
338 	/* Select logical device A (runtime registers) */
339 	sch311x_sio_outb(sio_config_port, 0x07, 0x0a);
340 
341 	/* Check if Logical Device Register is currently active */
342 	if ((sch311x_sio_inb(sio_config_port, 0x30) & 0x01) == 0)
343 		pr_info("Seems that LDN 0x0a is not active...\n");
344 
345 	/* Get the base address of the runtime registers */
346 	base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) |
347 			   sch311x_sio_inb(sio_config_port, 0x61);
348 	if (!base_addr) {
349 		pr_err("Base address not set\n");
350 		err = -ENODEV;
351 		goto exit;
352 	}
353 	*addr = base_addr;
354 
355 	pr_info("Found an SMSC SCH311%d chip at 0x%04x\n", dev_id, base_addr);
356 
357 exit:
358 	sch311x_sio_exit(sio_config_port);
359 	return err;
360 }
361 
362 static int __init sch311x_gpio_pdev_add(const unsigned short addr)
363 {
364 	struct sch311x_pdev_data pdata;
365 	int err;
366 
367 	pdata.runtime_reg = addr;
368 
369 	sch311x_gpio_pdev = platform_device_alloc(DRV_NAME, -1);
370 	if (!sch311x_gpio_pdev)
371 		return -ENOMEM;
372 
373 	err = platform_device_add_data(sch311x_gpio_pdev,
374 				       &pdata, sizeof(pdata));
375 	if (err) {
376 		pr_err(DRV_NAME "Platform data allocation failed\n");
377 		goto err;
378 	}
379 
380 	err = platform_device_add(sch311x_gpio_pdev);
381 	if (err) {
382 		pr_err(DRV_NAME "Device addition failed\n");
383 		goto err;
384 	}
385 	return 0;
386 
387 err:
388 	platform_device_put(sch311x_gpio_pdev);
389 	return err;
390 }
391 
392 static int __init sch311x_gpio_init(void)
393 {
394 	int err, i;
395 	unsigned short addr = 0;
396 
397 	for (i = 0; i < ARRAY_SIZE(sch311x_ioports); i++)
398 		if (sch311x_detect(sch311x_ioports[i], &addr) == 0)
399 			break;
400 
401 	if (!addr)
402 		return -ENODEV;
403 
404 	err = platform_driver_register(&sch311x_gpio_driver);
405 	if (err)
406 		return err;
407 
408 	err = sch311x_gpio_pdev_add(addr);
409 	if (err)
410 		goto unreg_platform_driver;
411 
412 	return 0;
413 
414 unreg_platform_driver:
415 	platform_driver_unregister(&sch311x_gpio_driver);
416 	return err;
417 }
418 
419 static void __exit sch311x_gpio_exit(void)
420 {
421 	platform_device_unregister(sch311x_gpio_pdev);
422 	platform_driver_unregister(&sch311x_gpio_driver);
423 }
424 
425 module_init(sch311x_gpio_init);
426 module_exit(sch311x_gpio_exit);
427 
428 MODULE_AUTHOR("Bruno Randolf <br1@einfach.org>");
429 MODULE_DESCRIPTION("SMSC SCH311x GPIO Driver");
430 MODULE_LICENSE("GPL");
431 MODULE_ALIAS("platform:gpio-sch311x");
432