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 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
308static 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
320static 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
358exit:
359	sch311x_sio_exit(sio_config_port);
360	return err;
361}
362
363static 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
388err:
389	platform_device_put(sch311x_gpio_pdev);
390	return err;
391}
392
393static 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
415unreg_platform_driver:
416	platform_driver_unregister(&sch311x_gpio_driver);
417	return err;
418}
419
420static void __exit sch311x_gpio_exit(void)
421{
422	platform_device_unregister(sch311x_gpio_pdev);
423	platform_driver_unregister(&sch311x_gpio_driver);
424}
425
426module_init(sch311x_gpio_init);
427module_exit(sch311x_gpio_exit);
428
429MODULE_AUTHOR("Bruno Randolf <br1@einfach.org>");
430MODULE_DESCRIPTION("SMSC SCH311x GPIO Driver");
431MODULE_LICENSE("GPL");
432MODULE_ALIAS("platform:gpio-sch311x");