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/ioport.h>
 16#include <linux/module.h>
 17#include <linux/kernel.h>
 18#include <linux/init.h>
 19#include <linux/platform_device.h>
 20#include <linux/gpio.h>
 21#include <linux/bitops.h>
 22#include <linux/io.h>
 23
 24#define DRV_NAME			"gpio-sch311x"
 25
 26#define SCH311X_GPIO_CONF_OUT		0x00
 27#define SCH311X_GPIO_CONF_IN		0x01
 28#define SCH311X_GPIO_CONF_INVERT	0x02
 29#define SCH311X_GPIO_CONF_OPEN_DRAIN	0x80
 30
 31#define SIO_CONFIG_KEY_ENTER		0x55
 32#define SIO_CONFIG_KEY_EXIT		0xaa
 33
 34#define GP1				0x4b
 35
 36static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e };
 37
 38static struct platform_device *sch311x_gpio_pdev;
 39
 40struct sch311x_pdev_data {		/* platform device data */
 41	unsigned short runtime_reg;	/* runtime register base address */
 42};
 43
 44struct sch311x_gpio_block {		/* one GPIO block runtime data */
 45	struct gpio_chip chip;
 46	unsigned short data_reg;	/* from definition below */
 47	unsigned short *config_regs;	/* pointer to definition below */
 48	unsigned short runtime_reg;	/* runtime register */
 49	spinlock_t lock;		/* lock for this GPIO block */
 50};
 51
 52struct sch311x_gpio_priv {		/* driver private data */
 53	struct sch311x_gpio_block blocks[6];
 54};
 55
 56struct sch311x_gpio_block_def {		/* register address definitions */
 57	unsigned short data_reg;
 58	unsigned short config_regs[8];
 59	unsigned short base;
 60};
 61
 62/* Note: some GPIOs are not available, these are marked with 0x00 */
 63
 64static struct sch311x_gpio_block_def sch311x_gpio_blocks[] = {
 65	{
 66		.data_reg = 0x4b,	/* GP1 */
 67		.config_regs = {0x23, 0x24, 0x25, 0x26, 0x27, 0x29, 0x2a, 0x2b},
 68		.base = 10,
 69	},
 70	{
 71		.data_reg = 0x4c,	/* GP2 */
 72		.config_regs = {0x00, 0x2c, 0x2d, 0x00, 0x00, 0x00, 0x00, 0x32},
 73		.base = 20,
 74	},
 75	{
 76		.data_reg = 0x4d,	/* GP3 */
 77		.config_regs = {0x33, 0x34, 0x35, 0x36, 0x37, 0x00, 0x39, 0x3a},
 78		.base = 30,
 79	},
 80	{
 81		.data_reg = 0x4e,	/* GP4 */
 82		.config_regs = {0x3b, 0x00, 0x3d, 0x00, 0x6e, 0x6f, 0x72, 0x73},
 83		.base = 40,
 84	},
 85	{
 86		.data_reg = 0x4f,	/* GP5 */
 87		.config_regs = {0x3f, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46},
 88		.base = 50,
 89	},
 90	{
 91		.data_reg = 0x50,	/* GP6 */
 92		.config_regs = {0x47, 0x48, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59},
 93		.base = 60,
 94	},
 95};
 96
 97/*
 98 *	Super-IO functions
 99 */
100
101static inline int sch311x_sio_enter(int sio_config_port)
102{
103	/* Don't step on other drivers' I/O space by accident. */
104	if (!request_muxed_region(sio_config_port, 2, DRV_NAME)) {
105		pr_err(DRV_NAME "I/O address 0x%04x already in use\n",
106		       sio_config_port);
107		return -EBUSY;
108	}
109
110	outb(SIO_CONFIG_KEY_ENTER, sio_config_port);
111	return 0;
112}
113
114static inline void sch311x_sio_exit(int sio_config_port)
115{
116	outb(SIO_CONFIG_KEY_EXIT, sio_config_port);
117	release_region(sio_config_port, 2);
118}
119
120static inline int sch311x_sio_inb(int sio_config_port, int reg)
121{
122	outb(reg, sio_config_port);
123	return inb(sio_config_port + 1);
124}
125
126static inline void sch311x_sio_outb(int sio_config_port, int reg, int val)
127{
128	outb(reg, sio_config_port);
129	outb(val, sio_config_port + 1);
130}
131
132
133/*
134 *	GPIO functions
135 */
136
137static int sch311x_gpio_request(struct gpio_chip *chip, unsigned offset)
138{
139	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
140
141	if (block->config_regs[offset] == 0) /* GPIO is not available */
142		return -ENODEV;
143
144	if (!request_region(block->runtime_reg + block->config_regs[offset],
145			    1, DRV_NAME)) {
146		dev_err(chip->parent, "Failed to request region 0x%04x.\n",
147			block->runtime_reg + block->config_regs[offset]);
148		return -EBUSY;
149	}
150	return 0;
151}
152
153static void sch311x_gpio_free(struct gpio_chip *chip, unsigned offset)
154{
155	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
156
157	if (block->config_regs[offset] == 0) /* GPIO is not available */
158		return;
159
160	release_region(block->runtime_reg + block->config_regs[offset], 1);
161}
162
163static int sch311x_gpio_get(struct gpio_chip *chip, unsigned offset)
164{
165	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
166	unsigned char data;
167
168	spin_lock(&block->lock);
169	data = inb(block->runtime_reg + block->data_reg);
170	spin_unlock(&block->lock);
171
172	return !!(data & BIT(offset));
173}
174
175static void __sch311x_gpio_set(struct sch311x_gpio_block *block,
176			       unsigned offset, int value)
177{
178	unsigned char data = inb(block->runtime_reg + block->data_reg);
179	if (value)
180		data |= BIT(offset);
181	else
182		data &= ~BIT(offset);
183	outb(data, block->runtime_reg + block->data_reg);
184}
185
186static void sch311x_gpio_set(struct gpio_chip *chip, unsigned offset,
187			     int value)
188{
189	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
190
191	spin_lock(&block->lock);
192	 __sch311x_gpio_set(block, offset, value);
193	spin_unlock(&block->lock);
194}
195
196static int sch311x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
197{
198	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
199
200	spin_lock(&block->lock);
201	outb(SCH311X_GPIO_CONF_IN, block->runtime_reg +
202	     block->config_regs[offset]);
203	spin_unlock(&block->lock);
204
205	return 0;
206}
207
208static int sch311x_gpio_direction_out(struct gpio_chip *chip, unsigned offset,
209				      int value)
210{
211	struct sch311x_gpio_block *block = gpiochip_get_data(chip);
212
213	spin_lock(&block->lock);
214
215	outb(SCH311X_GPIO_CONF_OUT, block->runtime_reg +
216	     block->config_regs[offset]);
217
218	__sch311x_gpio_set(block, offset, value);
219
220	spin_unlock(&block->lock);
221	return 0;
222}
223
224static int sch311x_gpio_probe(struct platform_device *pdev)
225{
226	struct sch311x_pdev_data *pdata = dev_get_platdata(&pdev->dev);
227	struct sch311x_gpio_priv *priv;
228	struct sch311x_gpio_block *block;
229	int err, i;
230
231	/* we can register all GPIO data registers at once */
232	if (!devm_request_region(&pdev->dev, pdata->runtime_reg + GP1, 6,
233		DRV_NAME)) {
234		dev_err(&pdev->dev, "Failed to request region 0x%04x-0x%04x.\n",
235			pdata->runtime_reg + GP1, pdata->runtime_reg + GP1 + 5);
236		return -EBUSY;
237	}
238
239	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
240	if (!priv)
241		return -ENOMEM;
242
243	platform_set_drvdata(pdev, priv);
244
245	for (i = 0; i < ARRAY_SIZE(priv->blocks); i++) {
246		block = &priv->blocks[i];
247
248		spin_lock_init(&block->lock);
249
250		block->chip.label = DRV_NAME;
251		block->chip.owner = THIS_MODULE;
252		block->chip.request = sch311x_gpio_request;
253		block->chip.free = sch311x_gpio_free;
254		block->chip.direction_input = sch311x_gpio_direction_in;
255		block->chip.direction_output = sch311x_gpio_direction_out;
256		block->chip.get = sch311x_gpio_get;
257		block->chip.set = sch311x_gpio_set;
258		block->chip.ngpio = 8;
259		block->chip.parent = &pdev->dev;
260		block->chip.base = sch311x_gpio_blocks[i].base;
261		block->config_regs = sch311x_gpio_blocks[i].config_regs;
262		block->data_reg = sch311x_gpio_blocks[i].data_reg;
263		block->runtime_reg = pdata->runtime_reg;
264
265		err = gpiochip_add_data(&block->chip, block);
266		if (err < 0) {
267			dev_err(&pdev->dev,
268				"Could not register gpiochip, %d\n", err);
269			goto exit_err;
270		}
271		dev_info(&pdev->dev,
272			 "SMSC SCH311x GPIO block %d registered.\n", i);
273	}
274
275	return 0;
276
277exit_err:
278	/* release already registered chips */
279	for (--i; i >= 0; i--)
280		gpiochip_remove(&priv->blocks[i].chip);
281	return err;
282}
283
284static int sch311x_gpio_remove(struct platform_device *pdev)
285{
286	struct sch311x_gpio_priv *priv = platform_get_drvdata(pdev);
287	int i;
288
289	for (i = 0; i < ARRAY_SIZE(priv->blocks); i++) {
290		gpiochip_remove(&priv->blocks[i].chip);
291		dev_info(&pdev->dev,
292			 "SMSC SCH311x GPIO block %d unregistered.\n", i);
293	}
294	return 0;
295}
296
297static struct platform_driver sch311x_gpio_driver = {
298	.driver.name	= DRV_NAME,
299	.probe		= sch311x_gpio_probe,
300	.remove		= sch311x_gpio_remove,
301};
302
303
304/*
305 *	Init & exit routines
306 */
307
308static int __init sch311x_detect(int sio_config_port, unsigned short *addr)
309{
310	int err = 0, reg;
311	unsigned short base_addr;
312	unsigned char dev_id;
313
314	err = sch311x_sio_enter(sio_config_port);
315	if (err)
316		return err;
317
318	/* Check device ID. */
319	reg = sch311x_sio_inb(sio_config_port, 0x20);
320	switch (reg) {
321	case 0x7c: /* SCH3112 */
322		dev_id = 2;
323		break;
324	case 0x7d: /* SCH3114 */
325		dev_id = 4;
326		break;
327	case 0x7f: /* SCH3116 */
328		dev_id = 6;
329		break;
330	default:
331		err = -ENODEV;
332		goto exit;
333	}
334
335	/* Select logical device A (runtime registers) */
336	sch311x_sio_outb(sio_config_port, 0x07, 0x0a);
337
338	/* Check if Logical Device Register is currently active */
339	if ((sch311x_sio_inb(sio_config_port, 0x30) & 0x01) == 0)
340		pr_info("Seems that LDN 0x0a is not active...\n");
341
342	/* Get the base address of the runtime registers */
343	base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) |
344			   sch311x_sio_inb(sio_config_port, 0x61);
345	if (!base_addr) {
346		pr_err("Base address not set\n");
347		err = -ENODEV;
348		goto exit;
349	}
350	*addr = base_addr;
351
352	pr_info("Found an SMSC SCH311%d chip at 0x%04x\n", dev_id, base_addr);
353
354exit:
355	sch311x_sio_exit(sio_config_port);
356	return err;
357}
358
359static int __init sch311x_gpio_pdev_add(const unsigned short addr)
360{
361	struct sch311x_pdev_data pdata;
362	int err;
363
364	pdata.runtime_reg = addr;
365
366	sch311x_gpio_pdev = platform_device_alloc(DRV_NAME, -1);
367	if (!sch311x_gpio_pdev)
368		return -ENOMEM;
369
370	err = platform_device_add_data(sch311x_gpio_pdev,
371				       &pdata, sizeof(pdata));
372	if (err) {
373		pr_err(DRV_NAME "Platform data allocation failed\n");
374		goto err;
375	}
376
377	err = platform_device_add(sch311x_gpio_pdev);
378	if (err) {
379		pr_err(DRV_NAME "Device addition failed\n");
380		goto err;
381	}
382	return 0;
383
384err:
385	platform_device_put(sch311x_gpio_pdev);
386	return err;
387}
388
389static int __init sch311x_gpio_init(void)
390{
391	int err, i;
392	unsigned short addr = 0;
393
394	for (i = 0; i < ARRAY_SIZE(sch311x_ioports); i++)
395		if (sch311x_detect(sch311x_ioports[i], &addr) == 0)
396			break;
397
398	if (!addr)
399		return -ENODEV;
400
401	err = platform_driver_register(&sch311x_gpio_driver);
402	if (err)
403		return err;
404
405	err = sch311x_gpio_pdev_add(addr);
406	if (err)
407		goto unreg_platform_driver;
408
409	return 0;
410
411unreg_platform_driver:
412	platform_driver_unregister(&sch311x_gpio_driver);
413	return err;
414}
415
416static void __exit sch311x_gpio_exit(void)
417{
418	platform_device_unregister(sch311x_gpio_pdev);
419	platform_driver_unregister(&sch311x_gpio_driver);
420}
421
422module_init(sch311x_gpio_init);
423module_exit(sch311x_gpio_exit);
424
425MODULE_AUTHOR("Bruno Randolf <br1@einfach.org>");
426MODULE_DESCRIPTION("SMSC SCH311x GPIO Driver");
427MODULE_LICENSE("GPL");
428MODULE_ALIAS("platform:gpio-sch311x");