xref: /openbmc/linux/drivers/gpio/gpio-sch311x.c (revision f7018c21)
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 static inline struct sch311x_gpio_block *
97 to_sch311x_gpio_block(struct gpio_chip *chip)
98 {
99 	return container_of(chip, struct sch311x_gpio_block, chip);
100 }
101 
102 
103 /*
104  *	Super-IO functions
105  */
106 
107 static inline int sch311x_sio_enter(int sio_config_port)
108 {
109 	/* Don't step on other drivers' I/O space by accident. */
110 	if (!request_muxed_region(sio_config_port, 2, DRV_NAME)) {
111 		pr_err(DRV_NAME "I/O address 0x%04x already in use\n",
112 		       sio_config_port);
113 		return -EBUSY;
114 	}
115 
116 	outb(SIO_CONFIG_KEY_ENTER, sio_config_port);
117 	return 0;
118 }
119 
120 static inline void sch311x_sio_exit(int sio_config_port)
121 {
122 	outb(SIO_CONFIG_KEY_EXIT, sio_config_port);
123 	release_region(sio_config_port, 2);
124 }
125 
126 static inline int sch311x_sio_inb(int sio_config_port, int reg)
127 {
128 	outb(reg, sio_config_port);
129 	return inb(sio_config_port + 1);
130 }
131 
132 static inline void sch311x_sio_outb(int sio_config_port, int reg, int val)
133 {
134 	outb(reg, sio_config_port);
135 	outb(val, sio_config_port + 1);
136 }
137 
138 
139 /*
140  *	GPIO functions
141  */
142 
143 static int sch311x_gpio_request(struct gpio_chip *chip, unsigned offset)
144 {
145 	struct sch311x_gpio_block *block = to_sch311x_gpio_block(chip);
146 
147 	if (block->config_regs[offset] == 0) /* GPIO is not available */
148 		return -ENODEV;
149 
150 	if (!request_region(block->runtime_reg + block->config_regs[offset],
151 			    1, DRV_NAME)) {
152 		dev_err(chip->dev, "Failed to request region 0x%04x.\n",
153 			block->runtime_reg + block->config_regs[offset]);
154 		return -EBUSY;
155 	}
156 	return 0;
157 }
158 
159 static void sch311x_gpio_free(struct gpio_chip *chip, unsigned offset)
160 {
161 	struct sch311x_gpio_block *block = to_sch311x_gpio_block(chip);
162 
163 	if (block->config_regs[offset] == 0) /* GPIO is not available */
164 		return;
165 
166 	release_region(block->runtime_reg + block->config_regs[offset], 1);
167 }
168 
169 static int sch311x_gpio_get(struct gpio_chip *chip, unsigned offset)
170 {
171 	struct sch311x_gpio_block *block = to_sch311x_gpio_block(chip);
172 	unsigned char data;
173 
174 	spin_lock(&block->lock);
175 	data = inb(block->runtime_reg + block->data_reg);
176 	spin_unlock(&block->lock);
177 
178 	return !!(data & BIT(offset));
179 }
180 
181 static void __sch311x_gpio_set(struct sch311x_gpio_block *block,
182 			       unsigned offset, int value)
183 {
184 	unsigned char data = inb(block->runtime_reg + block->data_reg);
185 	if (value)
186 		data |= BIT(offset);
187 	else
188 		data &= ~BIT(offset);
189 	outb(data, block->runtime_reg + block->data_reg);
190 }
191 
192 static void sch311x_gpio_set(struct gpio_chip *chip, unsigned offset,
193 			     int value)
194 {
195 	struct sch311x_gpio_block *block = to_sch311x_gpio_block(chip);
196 
197 	spin_lock(&block->lock);
198 	 __sch311x_gpio_set(block, offset, value);
199 	spin_unlock(&block->lock);
200 }
201 
202 static int sch311x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
203 {
204 	struct sch311x_gpio_block *block = to_sch311x_gpio_block(chip);
205 
206 	spin_lock(&block->lock);
207 	outb(SCH311X_GPIO_CONF_IN, block->runtime_reg +
208 	     block->config_regs[offset]);
209 	spin_unlock(&block->lock);
210 
211 	return 0;
212 }
213 
214 static int sch311x_gpio_direction_out(struct gpio_chip *chip, unsigned offset,
215 				      int value)
216 {
217 	struct sch311x_gpio_block *block = to_sch311x_gpio_block(chip);
218 
219 	spin_lock(&block->lock);
220 
221 	outb(SCH311X_GPIO_CONF_OUT, block->runtime_reg +
222 	     block->config_regs[offset]);
223 
224 	__sch311x_gpio_set(block, offset, value);
225 
226 	spin_unlock(&block->lock);
227 	return 0;
228 }
229 
230 static int sch311x_gpio_probe(struct platform_device *pdev)
231 {
232 	struct sch311x_pdev_data *pdata = pdev->dev.platform_data;
233 	struct sch311x_gpio_priv *priv;
234 	struct sch311x_gpio_block *block;
235 	int err, i;
236 
237 	/* we can register all GPIO data registers at once */
238 	if (!request_region(pdata->runtime_reg + GP1, 6, DRV_NAME)) {
239 		dev_err(&pdev->dev, "Failed to request region 0x%04x-0x%04x.\n",
240 			pdata->runtime_reg + GP1, pdata->runtime_reg + GP1 + 5);
241 		return -EBUSY;
242 	}
243 
244 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
245 	if (!priv)
246 		return -ENOMEM;
247 
248 	platform_set_drvdata(pdev, priv);
249 
250 	for (i = 0; i < ARRAY_SIZE(priv->blocks); i++) {
251 		block = &priv->blocks[i];
252 
253 		spin_lock_init(&block->lock);
254 
255 		block->chip.label = DRV_NAME;
256 		block->chip.owner = THIS_MODULE;
257 		block->chip.request = sch311x_gpio_request;
258 		block->chip.free = sch311x_gpio_free;
259 		block->chip.direction_input = sch311x_gpio_direction_in;
260 		block->chip.direction_output = sch311x_gpio_direction_out;
261 		block->chip.get = sch311x_gpio_get;
262 		block->chip.set = sch311x_gpio_set;
263 		block->chip.ngpio = 8;
264 		block->chip.dev = &pdev->dev;
265 		block->chip.base = sch311x_gpio_blocks[i].base;
266 		block->config_regs = sch311x_gpio_blocks[i].config_regs;
267 		block->data_reg = sch311x_gpio_blocks[i].data_reg;
268 		block->runtime_reg = pdata->runtime_reg;
269 
270 		err = gpiochip_add(&block->chip);
271 		if (err < 0) {
272 			dev_err(&pdev->dev,
273 				"Could not register gpiochip, %d\n", err);
274 			goto exit_err;
275 		}
276 		dev_info(&pdev->dev,
277 			 "SMSC SCH311x GPIO block %d registered.\n", i);
278 	}
279 
280 	return 0;
281 
282 exit_err:
283 	release_region(pdata->runtime_reg + GP1, 6);
284 	/* release already registered chips */
285 	for (--i; i >= 0; i--)
286 		gpiochip_remove(&priv->blocks[i].chip);
287 	return err;
288 }
289 
290 static int sch311x_gpio_remove(struct platform_device *pdev)
291 {
292 	struct sch311x_pdev_data *pdata = pdev->dev.platform_data;
293 	struct sch311x_gpio_priv *priv = platform_get_drvdata(pdev);
294 	int err, i;
295 
296 	release_region(pdata->runtime_reg + GP1, 6);
297 
298 	for (i = 0; i < ARRAY_SIZE(priv->blocks); i++) {
299 		err = gpiochip_remove(&priv->blocks[i].chip);
300 		if (err)
301 			return err;
302 		dev_info(&pdev->dev,
303 			 "SMSC SCH311x GPIO block %d unregistered.\n", i);
304 	}
305 	return 0;
306 }
307 
308 static struct platform_driver sch311x_gpio_driver = {
309 	.driver.name	= DRV_NAME,
310 	.driver.owner	= THIS_MODULE,
311 	.probe		= sch311x_gpio_probe,
312 	.remove		= sch311x_gpio_remove,
313 };
314 
315 
316 /*
317  *	Init & exit routines
318  */
319 
320 static int __init sch311x_detect(int sio_config_port, unsigned short *addr)
321 {
322 	int err = 0, reg;
323 	unsigned short base_addr;
324 	unsigned char dev_id;
325 
326 	err = sch311x_sio_enter(sio_config_port);
327 	if (err)
328 		return err;
329 
330 	/* Check device ID. We currently know about:
331 	 * SCH3112 (0x7c), SCH3114 (0x7d), and SCH3116 (0x7f). */
332 	reg = sch311x_sio_inb(sio_config_port, 0x20);
333 	if (!(reg == 0x7c || reg == 0x7d || reg == 0x7f)) {
334 		err = -ENODEV;
335 		goto exit;
336 	}
337 	dev_id = reg == 0x7c ? 2 : reg == 0x7d ? 4 : 6;
338 
339 	/* Select logical device A (runtime registers) */
340 	sch311x_sio_outb(sio_config_port, 0x07, 0x0a);
341 
342 	/* Check if Logical Device Register is currently active */
343 	if ((sch311x_sio_inb(sio_config_port, 0x30) & 0x01) == 0)
344 		pr_info("Seems that LDN 0x0a is not active...\n");
345 
346 	/* Get the base address of the runtime registers */
347 	base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) |
348 			   sch311x_sio_inb(sio_config_port, 0x61);
349 	if (!base_addr) {
350 		pr_err("Base address not set\n");
351 		err = -ENODEV;
352 		goto exit;
353 	}
354 	*addr = base_addr;
355 
356 	pr_info("Found an SMSC SCH311%d chip at 0x%04x\n", dev_id, base_addr);
357 
358 exit:
359 	sch311x_sio_exit(sio_config_port);
360 	return err;
361 }
362 
363 static int __init sch311x_gpio_pdev_add(const unsigned short addr)
364 {
365 	struct sch311x_pdev_data pdata;
366 	int err;
367 
368 	pdata.runtime_reg = addr;
369 
370 	sch311x_gpio_pdev = platform_device_alloc(DRV_NAME, -1);
371 	if (!sch311x_gpio_pdev)
372 		return -ENOMEM;
373 
374 	err = platform_device_add_data(sch311x_gpio_pdev,
375 				       &pdata, sizeof(pdata));
376 	if (err) {
377 		pr_err(DRV_NAME "Platform data allocation failed\n");
378 		goto err;
379 	}
380 
381 	err = platform_device_add(sch311x_gpio_pdev);
382 	if (err) {
383 		pr_err(DRV_NAME "Device addition failed\n");
384 		goto err;
385 	}
386 	return 0;
387 
388 err:
389 	platform_device_put(sch311x_gpio_pdev);
390 	return err;
391 }
392 
393 static int __init sch311x_gpio_init(void)
394 {
395 	int err, i;
396 	unsigned short addr = 0;
397 
398 	for (i = 0; i < ARRAY_SIZE(sch311x_ioports); i++)
399 		if (sch311x_detect(sch311x_ioports[i], &addr) == 0)
400 			break;
401 
402 	if (!addr)
403 		return -ENODEV;
404 
405 	err = platform_driver_register(&sch311x_gpio_driver);
406 	if (err)
407 		return err;
408 
409 	err = sch311x_gpio_pdev_add(addr);
410 	if (err)
411 		goto unreg_platform_driver;
412 
413 	return 0;
414 
415 unreg_platform_driver:
416 	platform_driver_unregister(&sch311x_gpio_driver);
417 	return err;
418 }
419 
420 static void __exit sch311x_gpio_exit(void)
421 {
422 	platform_device_unregister(sch311x_gpio_pdev);
423 	platform_driver_unregister(&sch311x_gpio_driver);
424 }
425 
426 module_init(sch311x_gpio_init);
427 module_exit(sch311x_gpio_exit);
428 
429 MODULE_AUTHOR("Bruno Randolf <br1@einfach.org>");
430 MODULE_DESCRIPTION("SMSC SCH311x GPIO Driver");
431 MODULE_LICENSE("GPL");
432 MODULE_ALIAS("platform:gpio-sch311x");
433