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
35static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e };
36
37static struct platform_device *sch311x_gpio_pdev;
38
39struct sch311x_pdev_data {		/* platform device data */
40	unsigned short runtime_reg;	/* runtime register base address */
41};
42
43struct 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
51struct sch311x_gpio_priv {		/* driver private data */
52	struct sch311x_gpio_block blocks[6];
53};
54
55struct 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
63static 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
96static inline struct sch311x_gpio_block *
97to_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
107static 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
120static 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
126static 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
132static 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
143static 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
159static 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
169static 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
181static 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
192static 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
202static 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
214static 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
230static 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
282exit_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
290static 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 i;
295
296	release_region(pdata->runtime_reg + GP1, 6);
297
298	for (i = 0; i < ARRAY_SIZE(priv->blocks); i++) {
299		gpiochip_remove(&priv->blocks[i].chip);
300		dev_info(&pdev->dev,
301			 "SMSC SCH311x GPIO block %d unregistered.\n", i);
302	}
303	return 0;
304}
305
306static struct platform_driver sch311x_gpio_driver = {
307	.driver.name	= DRV_NAME,
308	.driver.owner	= THIS_MODULE,
309	.probe		= sch311x_gpio_probe,
310	.remove		= sch311x_gpio_remove,
311};
312
313
314/*
315 *	Init & exit routines
316 */
317
318static int __init sch311x_detect(int sio_config_port, unsigned short *addr)
319{
320	int err = 0, reg;
321	unsigned short base_addr;
322	unsigned char dev_id;
323
324	err = sch311x_sio_enter(sio_config_port);
325	if (err)
326		return err;
327
328	/* Check device ID. */
329	reg = sch311x_sio_inb(sio_config_port, 0x20);
330	switch (reg) {
331	case 0x7c: /* SCH3112 */
332		dev_id = 2;
333		break;
334	case 0x7d: /* SCH3114 */
335		dev_id = 4;
336		break;
337	case 0x7f: /* SCH3116 */
338		dev_id = 6;
339		break;
340	default:
341		err = -ENODEV;
342		goto exit;
343	}
344
345	/* Select logical device A (runtime registers) */
346	sch311x_sio_outb(sio_config_port, 0x07, 0x0a);
347
348	/* Check if Logical Device Register is currently active */
349	if ((sch311x_sio_inb(sio_config_port, 0x30) & 0x01) == 0)
350		pr_info("Seems that LDN 0x0a is not active...\n");
351
352	/* Get the base address of the runtime registers */
353	base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) |
354			   sch311x_sio_inb(sio_config_port, 0x61);
355	if (!base_addr) {
356		pr_err("Base address not set\n");
357		err = -ENODEV;
358		goto exit;
359	}
360	*addr = base_addr;
361
362	pr_info("Found an SMSC SCH311%d chip at 0x%04x\n", dev_id, base_addr);
363
364exit:
365	sch311x_sio_exit(sio_config_port);
366	return err;
367}
368
369static int __init sch311x_gpio_pdev_add(const unsigned short addr)
370{
371	struct sch311x_pdev_data pdata;
372	int err;
373
374	pdata.runtime_reg = addr;
375
376	sch311x_gpio_pdev = platform_device_alloc(DRV_NAME, -1);
377	if (!sch311x_gpio_pdev)
378		return -ENOMEM;
379
380	err = platform_device_add_data(sch311x_gpio_pdev,
381				       &pdata, sizeof(pdata));
382	if (err) {
383		pr_err(DRV_NAME "Platform data allocation failed\n");
384		goto err;
385	}
386
387	err = platform_device_add(sch311x_gpio_pdev);
388	if (err) {
389		pr_err(DRV_NAME "Device addition failed\n");
390		goto err;
391	}
392	return 0;
393
394err:
395	platform_device_put(sch311x_gpio_pdev);
396	return err;
397}
398
399static int __init sch311x_gpio_init(void)
400{
401	int err, i;
402	unsigned short addr = 0;
403
404	for (i = 0; i < ARRAY_SIZE(sch311x_ioports); i++)
405		if (sch311x_detect(sch311x_ioports[i], &addr) == 0)
406			break;
407
408	if (!addr)
409		return -ENODEV;
410
411	err = platform_driver_register(&sch311x_gpio_driver);
412	if (err)
413		return err;
414
415	err = sch311x_gpio_pdev_add(addr);
416	if (err)
417		goto unreg_platform_driver;
418
419	return 0;
420
421unreg_platform_driver:
422	platform_driver_unregister(&sch311x_gpio_driver);
423	return err;
424}
425
426static void __exit sch311x_gpio_exit(void)
427{
428	platform_device_unregister(sch311x_gpio_pdev);
429	platform_driver_unregister(&sch311x_gpio_driver);
430}
431
432module_init(sch311x_gpio_init);
433module_exit(sch311x_gpio_exit);
434
435MODULE_AUTHOR("Bruno Randolf <br1@einfach.org>");
436MODULE_DESCRIPTION("SMSC SCH311x GPIO Driver");
437MODULE_LICENSE("GPL");
438MODULE_ALIAS("platform:gpio-sch311x");
439