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v4.6
  1/*
  2 *  GPIO interface for IT87xx Super I/O chips
  3 *
  4 *  Author: Diego Elio Pettenò <flameeyes@flameeyes.eu>
  5 *
  6 *  Based on it87_wdt.c     by Oliver Schuster
  7 *           gpio-it8761e.c by Denis Turischev
  8 *           gpio-stmpe.c   by Rabin Vincent
  9 *
 10 *  This program is free software; you can redistribute it and/or modify
 11 *  it under the terms of the GNU General Public License 2 as published
 12 *  by the Free Software Foundation.
 13 *
 14 *  This program is distributed in the hope that it will be useful,
 15 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 16 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 17 *  GNU General Public License for more details.
 18 *
 19 *  You should have received a copy of the GNU General Public License
 20 *  along with this program; see the file COPYING.  If not, write to
 21 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 22 */
 23
 24#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 25
 26#include <linux/init.h>
 27#include <linux/kernel.h>
 28#include <linux/module.h>
 29#include <linux/io.h>
 30#include <linux/errno.h>
 31#include <linux/ioport.h>
 32#include <linux/slab.h>
 33#include <linux/gpio.h>
 34
 35/* Chip Id numbers */
 36#define NO_DEV_ID	0xffff
 
 
 37#define IT8728_ID	0x8728
 38#define IT8732_ID	0x8732
 39#define IT8761_ID	0x8761
 40
 41/* IO Ports */
 42#define REG		0x2e
 43#define VAL		0x2f
 44
 45/* Logical device Numbers LDN */
 46#define GPIO		0x07
 47
 48/* Configuration Registers and Functions */
 49#define LDNREG		0x07
 50#define CHIPID		0x20
 51#define CHIPREV		0x22
 52
 53/**
 54 * struct it87_gpio - it87-specific GPIO chip
 55 * @chip the underlying gpio_chip structure
 56 * @lock a lock to avoid races between operations
 57 * @io_base base address for gpio ports
 58 * @io_size size of the port rage starting from io_base.
 59 * @output_base Super I/O register address for Output Enable register
 60 * @simple_base Super I/O 'Simple I/O' Enable register
 61 * @simple_size Super IO 'Simple I/O' Enable register size; this is
 62 *	required because IT87xx chips might only provide Simple I/O
 63 *	switches on a subset of lines, whereas the others keep the
 64 *	same status all time.
 65 */
 66struct it87_gpio {
 67	struct gpio_chip chip;
 68	spinlock_t lock;
 69	u16 io_base;
 70	u16 io_size;
 71	u8 output_base;
 72	u8 simple_base;
 73	u8 simple_size;
 74};
 75
 76static struct it87_gpio it87_gpio_chip = {
 77	.lock = __SPIN_LOCK_UNLOCKED(it87_gpio_chip.lock),
 78};
 79
 80/* Superio chip access functions; copied from wdt_it87 */
 81
 82static inline int superio_enter(void)
 83{
 84	/*
 85	 * Try to reserve REG and REG + 1 for exclusive access.
 86	 */
 87	if (!request_muxed_region(REG, 2, KBUILD_MODNAME))
 88		return -EBUSY;
 89
 90	outb(0x87, REG);
 91	outb(0x01, REG);
 92	outb(0x55, REG);
 93	outb(0x55, REG);
 94	return 0;
 95}
 96
 97static inline void superio_exit(void)
 98{
 99	outb(0x02, REG);
100	outb(0x02, VAL);
101	release_region(REG, 2);
102}
103
104static inline void superio_select(int ldn)
105{
106	outb(LDNREG, REG);
107	outb(ldn, VAL);
108}
109
110static inline int superio_inb(int reg)
111{
112	outb(reg, REG);
113	return inb(VAL);
114}
115
116static inline void superio_outb(int val, int reg)
117{
118	outb(reg, REG);
119	outb(val, VAL);
120}
121
122static inline int superio_inw(int reg)
123{
124	int val;
125
126	outb(reg++, REG);
127	val = inb(VAL) << 8;
128	outb(reg, REG);
129	val |= inb(VAL);
130	return val;
131}
132
133static inline void superio_outw(int val, int reg)
134{
135	outb(reg++, REG);
136	outb(val >> 8, VAL);
137	outb(reg, REG);
138	outb(val, VAL);
139}
140
141static inline void superio_set_mask(int mask, int reg)
142{
143	u8 curr_val = superio_inb(reg);
144	u8 new_val = curr_val | mask;
145
146	if (curr_val != new_val)
147		superio_outb(new_val, reg);
148}
149
150static inline void superio_clear_mask(int mask, int reg)
151{
152	u8 curr_val = superio_inb(reg);
153	u8 new_val = curr_val & ~mask;
154
155	if (curr_val != new_val)
156		superio_outb(new_val, reg);
157}
158
159static int it87_gpio_request(struct gpio_chip *chip, unsigned gpio_num)
160{
161	u8 mask, group;
162	int rc = 0;
163	struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
164
165	mask = 1 << (gpio_num % 8);
166	group = (gpio_num / 8);
167
168	spin_lock(&it87_gpio->lock);
169
170	rc = superio_enter();
171	if (rc)
172		goto exit;
173
174	/* not all the IT87xx chips support Simple I/O and not all of
175	 * them allow all the lines to be set/unset to Simple I/O.
176	 */
177	if (group < it87_gpio->simple_size)
178		superio_set_mask(mask, group + it87_gpio->simple_base);
179
180	/* clear output enable, setting the pin to input, as all the
181	 * newly-exported GPIO interfaces are set to input.
182	 */
183	superio_clear_mask(mask, group + it87_gpio->output_base);
184
185	superio_exit();
186
187exit:
188	spin_unlock(&it87_gpio->lock);
189	return rc;
190}
191
192static int it87_gpio_get(struct gpio_chip *chip, unsigned gpio_num)
193{
194	u16 reg;
195	u8 mask;
196	struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
197
198	mask = 1 << (gpio_num % 8);
199	reg = (gpio_num / 8) + it87_gpio->io_base;
200
201	return !!(inb(reg) & mask);
202}
203
204static int it87_gpio_direction_in(struct gpio_chip *chip, unsigned gpio_num)
205{
206	u8 mask, group;
207	int rc = 0;
208	struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
209
210	mask = 1 << (gpio_num % 8);
211	group = (gpio_num / 8);
212
213	spin_lock(&it87_gpio->lock);
214
215	rc = superio_enter();
216	if (rc)
217		goto exit;
218
219	/* clear the output enable bit */
220	superio_clear_mask(mask, group + it87_gpio->output_base);
221
222	superio_exit();
223
224exit:
225	spin_unlock(&it87_gpio->lock);
226	return rc;
227}
228
229static void it87_gpio_set(struct gpio_chip *chip,
230			  unsigned gpio_num, int val)
231{
232	u8 mask, curr_vals;
233	u16 reg;
234	struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
235
236	mask = 1 << (gpio_num % 8);
237	reg = (gpio_num / 8) + it87_gpio->io_base;
238
239	curr_vals = inb(reg);
240	if (val)
241		outb(curr_vals | mask, reg);
242	else
243		outb(curr_vals & ~mask, reg);
244}
245
246static int it87_gpio_direction_out(struct gpio_chip *chip,
247				   unsigned gpio_num, int val)
248{
249	u8 mask, group;
250	int rc = 0;
251	struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
252
253	mask = 1 << (gpio_num % 8);
254	group = (gpio_num / 8);
255
256	spin_lock(&it87_gpio->lock);
257
258	rc = superio_enter();
259	if (rc)
260		goto exit;
261
262	/* set the output enable bit */
263	superio_set_mask(mask, group + it87_gpio->output_base);
264
265	it87_gpio_set(chip, gpio_num, val);
266
267	superio_exit();
268
269exit:
270	spin_unlock(&it87_gpio->lock);
271	return rc;
272}
273
274static struct gpio_chip it87_template_chip = {
275	.label			= KBUILD_MODNAME,
276	.owner			= THIS_MODULE,
277	.request		= it87_gpio_request,
278	.get			= it87_gpio_get,
279	.direction_input	= it87_gpio_direction_in,
280	.set			= it87_gpio_set,
281	.direction_output	= it87_gpio_direction_out,
282	.base			= -1
283};
284
285static int __init it87_gpio_init(void)
286{
287	int rc = 0, i;
288	u16 chip_type;
289	u8 chip_rev, gpio_ba_reg;
290	char *labels, **labels_table;
291
292	struct it87_gpio *it87_gpio = &it87_gpio_chip;
293
294	rc = superio_enter();
295	if (rc)
296		return rc;
297
298	chip_type = superio_inw(CHIPID);
299	chip_rev  = superio_inb(CHIPREV) & 0x0f;
300	superio_exit();
301
302	it87_gpio->chip = it87_template_chip;
303
304	switch (chip_type) {
 
 
 
 
 
 
 
 
305	case IT8728_ID:
306	case IT8732_ID:
307		gpio_ba_reg = 0x62;
308		it87_gpio->io_size = 8;
309		it87_gpio->output_base = 0xc8;
310		it87_gpio->simple_base = 0xc0;
311		it87_gpio->simple_size = 5;
312		it87_gpio->chip.ngpio = 64;
313		break;
314	case IT8761_ID:
315		gpio_ba_reg = 0x60;
316		it87_gpio->io_size = 4;
317		it87_gpio->output_base = 0xf0;
318		it87_gpio->simple_size = 0;
319		it87_gpio->chip.ngpio = 16;
320		break;
321	case NO_DEV_ID:
322		pr_err("no device\n");
323		return -ENODEV;
324	default:
325		pr_err("Unknown Chip found, Chip %04x Revision %x\n",
326		       chip_type, chip_rev);
327		return -ENODEV;
328	}
329
330	rc = superio_enter();
331	if (rc)
332		return rc;
333
334	superio_select(GPIO);
335
336	/* fetch GPIO base address */
337	it87_gpio->io_base = superio_inw(gpio_ba_reg);
338
339	superio_exit();
340
341	pr_info("Found Chip IT%04x rev %x. %u GPIO lines starting at %04xh\n",
342		chip_type, chip_rev, it87_gpio->chip.ngpio,
343		it87_gpio->io_base);
344
345	if (!request_region(it87_gpio->io_base, it87_gpio->io_size,
346							KBUILD_MODNAME))
347		return -EBUSY;
348
349	/* Set up aliases for the GPIO connection.
350	 *
351	 * ITE documentation for recent chips such as the IT8728F
352	 * refers to the GPIO lines as GPxy, with a coordinates system
353	 * where x is the GPIO group (starting from 1) and y is the
354	 * bit within the group.
355	 *
356	 * By creating these aliases, we make it easier to understand
357	 * to which GPIO pin we're referring to.
358	 */
359	labels = kcalloc(it87_gpio->chip.ngpio, sizeof("it87_gpXY"),
360								GFP_KERNEL);
361	labels_table = kcalloc(it87_gpio->chip.ngpio, sizeof(const char *),
362								GFP_KERNEL);
363
364	if (!labels || !labels_table) {
365		rc = -ENOMEM;
366		goto labels_free;
367	}
368
369	for (i = 0; i < it87_gpio->chip.ngpio; i++) {
370		char *label = &labels[i * sizeof("it87_gpXY")];
371
372		sprintf(label, "it87_gp%u%u", 1+(i/8), i%8);
373		labels_table[i] = label;
374	}
375
376	it87_gpio->chip.names = (const char *const*)labels_table;
377
378	rc = gpiochip_add_data(&it87_gpio->chip, it87_gpio);
379	if (rc)
380		goto labels_free;
381
382	return 0;
383
384labels_free:
385	kfree(labels_table);
386	kfree(labels);
387	release_region(it87_gpio->io_base, it87_gpio->io_size);
388	return rc;
389}
390
391static void __exit it87_gpio_exit(void)
392{
393	struct it87_gpio *it87_gpio = &it87_gpio_chip;
394
395	gpiochip_remove(&it87_gpio->chip);
396	release_region(it87_gpio->io_base, it87_gpio->io_size);
397	kfree(it87_gpio->chip.names[0]);
398	kfree(it87_gpio->chip.names);
399}
400
401module_init(it87_gpio_init);
402module_exit(it87_gpio_exit);
403
404MODULE_AUTHOR("Diego Elio Pettenò <flameeyes@flameeyes.eu>");
405MODULE_DESCRIPTION("GPIO interface for IT87xx Super I/O chips");
406MODULE_LICENSE("GPL");
v4.10.11
  1/*
  2 *  GPIO interface for IT87xx Super I/O chips
  3 *
  4 *  Author: Diego Elio Pettenò <flameeyes@flameeyes.eu>
  5 *
  6 *  Based on it87_wdt.c     by Oliver Schuster
  7 *           gpio-it8761e.c by Denis Turischev
  8 *           gpio-stmpe.c   by Rabin Vincent
  9 *
 10 *  This program is free software; you can redistribute it and/or modify
 11 *  it under the terms of the GNU General Public License 2 as published
 12 *  by the Free Software Foundation.
 13 *
 14 *  This program is distributed in the hope that it will be useful,
 15 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 16 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 17 *  GNU General Public License for more details.
 18 *
 19 *  You should have received a copy of the GNU General Public License
 20 *  along with this program; see the file COPYING.  If not, write to
 21 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 22 */
 23
 24#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 25
 26#include <linux/init.h>
 27#include <linux/kernel.h>
 28#include <linux/module.h>
 29#include <linux/io.h>
 30#include <linux/errno.h>
 31#include <linux/ioport.h>
 32#include <linux/slab.h>
 33#include <linux/gpio.h>
 34
 35/* Chip Id numbers */
 36#define NO_DEV_ID	0xffff
 37#define IT8620_ID	0x8620
 38#define IT8628_ID	0x8628
 39#define IT8728_ID	0x8728
 40#define IT8732_ID	0x8732
 41#define IT8761_ID	0x8761
 42
 43/* IO Ports */
 44#define REG		0x2e
 45#define VAL		0x2f
 46
 47/* Logical device Numbers LDN */
 48#define GPIO		0x07
 49
 50/* Configuration Registers and Functions */
 51#define LDNREG		0x07
 52#define CHIPID		0x20
 53#define CHIPREV		0x22
 54
 55/**
 56 * struct it87_gpio - it87-specific GPIO chip
 57 * @chip the underlying gpio_chip structure
 58 * @lock a lock to avoid races between operations
 59 * @io_base base address for gpio ports
 60 * @io_size size of the port rage starting from io_base.
 61 * @output_base Super I/O register address for Output Enable register
 62 * @simple_base Super I/O 'Simple I/O' Enable register
 63 * @simple_size Super IO 'Simple I/O' Enable register size; this is
 64 *	required because IT87xx chips might only provide Simple I/O
 65 *	switches on a subset of lines, whereas the others keep the
 66 *	same status all time.
 67 */
 68struct it87_gpio {
 69	struct gpio_chip chip;
 70	spinlock_t lock;
 71	u16 io_base;
 72	u16 io_size;
 73	u8 output_base;
 74	u8 simple_base;
 75	u8 simple_size;
 76};
 77
 78static struct it87_gpio it87_gpio_chip = {
 79	.lock = __SPIN_LOCK_UNLOCKED(it87_gpio_chip.lock),
 80};
 81
 82/* Superio chip access functions; copied from wdt_it87 */
 83
 84static inline int superio_enter(void)
 85{
 86	/*
 87	 * Try to reserve REG and REG + 1 for exclusive access.
 88	 */
 89	if (!request_muxed_region(REG, 2, KBUILD_MODNAME))
 90		return -EBUSY;
 91
 92	outb(0x87, REG);
 93	outb(0x01, REG);
 94	outb(0x55, REG);
 95	outb(0x55, REG);
 96	return 0;
 97}
 98
 99static inline void superio_exit(void)
100{
101	outb(0x02, REG);
102	outb(0x02, VAL);
103	release_region(REG, 2);
104}
105
106static inline void superio_select(int ldn)
107{
108	outb(LDNREG, REG);
109	outb(ldn, VAL);
110}
111
112static inline int superio_inb(int reg)
113{
114	outb(reg, REG);
115	return inb(VAL);
116}
117
118static inline void superio_outb(int val, int reg)
119{
120	outb(reg, REG);
121	outb(val, VAL);
122}
123
124static inline int superio_inw(int reg)
125{
126	int val;
127
128	outb(reg++, REG);
129	val = inb(VAL) << 8;
130	outb(reg, REG);
131	val |= inb(VAL);
132	return val;
133}
134
135static inline void superio_outw(int val, int reg)
136{
137	outb(reg++, REG);
138	outb(val >> 8, VAL);
139	outb(reg, REG);
140	outb(val, VAL);
141}
142
143static inline void superio_set_mask(int mask, int reg)
144{
145	u8 curr_val = superio_inb(reg);
146	u8 new_val = curr_val | mask;
147
148	if (curr_val != new_val)
149		superio_outb(new_val, reg);
150}
151
152static inline void superio_clear_mask(int mask, int reg)
153{
154	u8 curr_val = superio_inb(reg);
155	u8 new_val = curr_val & ~mask;
156
157	if (curr_val != new_val)
158		superio_outb(new_val, reg);
159}
160
161static int it87_gpio_request(struct gpio_chip *chip, unsigned gpio_num)
162{
163	u8 mask, group;
164	int rc = 0;
165	struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
166
167	mask = 1 << (gpio_num % 8);
168	group = (gpio_num / 8);
169
170	spin_lock(&it87_gpio->lock);
171
172	rc = superio_enter();
173	if (rc)
174		goto exit;
175
176	/* not all the IT87xx chips support Simple I/O and not all of
177	 * them allow all the lines to be set/unset to Simple I/O.
178	 */
179	if (group < it87_gpio->simple_size)
180		superio_set_mask(mask, group + it87_gpio->simple_base);
181
182	/* clear output enable, setting the pin to input, as all the
183	 * newly-exported GPIO interfaces are set to input.
184	 */
185	superio_clear_mask(mask, group + it87_gpio->output_base);
186
187	superio_exit();
188
189exit:
190	spin_unlock(&it87_gpio->lock);
191	return rc;
192}
193
194static int it87_gpio_get(struct gpio_chip *chip, unsigned gpio_num)
195{
196	u16 reg;
197	u8 mask;
198	struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
199
200	mask = 1 << (gpio_num % 8);
201	reg = (gpio_num / 8) + it87_gpio->io_base;
202
203	return !!(inb(reg) & mask);
204}
205
206static int it87_gpio_direction_in(struct gpio_chip *chip, unsigned gpio_num)
207{
208	u8 mask, group;
209	int rc = 0;
210	struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
211
212	mask = 1 << (gpio_num % 8);
213	group = (gpio_num / 8);
214
215	spin_lock(&it87_gpio->lock);
216
217	rc = superio_enter();
218	if (rc)
219		goto exit;
220
221	/* clear the output enable bit */
222	superio_clear_mask(mask, group + it87_gpio->output_base);
223
224	superio_exit();
225
226exit:
227	spin_unlock(&it87_gpio->lock);
228	return rc;
229}
230
231static void it87_gpio_set(struct gpio_chip *chip,
232			  unsigned gpio_num, int val)
233{
234	u8 mask, curr_vals;
235	u16 reg;
236	struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
237
238	mask = 1 << (gpio_num % 8);
239	reg = (gpio_num / 8) + it87_gpio->io_base;
240
241	curr_vals = inb(reg);
242	if (val)
243		outb(curr_vals | mask, reg);
244	else
245		outb(curr_vals & ~mask, reg);
246}
247
248static int it87_gpio_direction_out(struct gpio_chip *chip,
249				   unsigned gpio_num, int val)
250{
251	u8 mask, group;
252	int rc = 0;
253	struct it87_gpio *it87_gpio = gpiochip_get_data(chip);
254
255	mask = 1 << (gpio_num % 8);
256	group = (gpio_num / 8);
257
258	spin_lock(&it87_gpio->lock);
259
260	rc = superio_enter();
261	if (rc)
262		goto exit;
263
264	/* set the output enable bit */
265	superio_set_mask(mask, group + it87_gpio->output_base);
266
267	it87_gpio_set(chip, gpio_num, val);
268
269	superio_exit();
270
271exit:
272	spin_unlock(&it87_gpio->lock);
273	return rc;
274}
275
276static const struct gpio_chip it87_template_chip = {
277	.label			= KBUILD_MODNAME,
278	.owner			= THIS_MODULE,
279	.request		= it87_gpio_request,
280	.get			= it87_gpio_get,
281	.direction_input	= it87_gpio_direction_in,
282	.set			= it87_gpio_set,
283	.direction_output	= it87_gpio_direction_out,
284	.base			= -1
285};
286
287static int __init it87_gpio_init(void)
288{
289	int rc = 0, i;
290	u16 chip_type;
291	u8 chip_rev, gpio_ba_reg;
292	char *labels, **labels_table;
293
294	struct it87_gpio *it87_gpio = &it87_gpio_chip;
295
296	rc = superio_enter();
297	if (rc)
298		return rc;
299
300	chip_type = superio_inw(CHIPID);
301	chip_rev  = superio_inb(CHIPREV) & 0x0f;
302	superio_exit();
303
304	it87_gpio->chip = it87_template_chip;
305
306	switch (chip_type) {
307	case IT8620_ID:
308	case IT8628_ID:
309		gpio_ba_reg = 0x62;
310		it87_gpio->io_size = 11;
311		it87_gpio->output_base = 0xc8;
312		it87_gpio->simple_size = 0;
313		it87_gpio->chip.ngpio = 64;
314		break;
315	case IT8728_ID:
316	case IT8732_ID:
317		gpio_ba_reg = 0x62;
318		it87_gpio->io_size = 8;
319		it87_gpio->output_base = 0xc8;
320		it87_gpio->simple_base = 0xc0;
321		it87_gpio->simple_size = 5;
322		it87_gpio->chip.ngpio = 64;
323		break;
324	case IT8761_ID:
325		gpio_ba_reg = 0x60;
326		it87_gpio->io_size = 4;
327		it87_gpio->output_base = 0xf0;
328		it87_gpio->simple_size = 0;
329		it87_gpio->chip.ngpio = 16;
330		break;
331	case NO_DEV_ID:
332		pr_err("no device\n");
333		return -ENODEV;
334	default:
335		pr_err("Unknown Chip found, Chip %04x Revision %x\n",
336		       chip_type, chip_rev);
337		return -ENODEV;
338	}
339
340	rc = superio_enter();
341	if (rc)
342		return rc;
343
344	superio_select(GPIO);
345
346	/* fetch GPIO base address */
347	it87_gpio->io_base = superio_inw(gpio_ba_reg);
348
349	superio_exit();
350
351	pr_info("Found Chip IT%04x rev %x. %u GPIO lines starting at %04xh\n",
352		chip_type, chip_rev, it87_gpio->chip.ngpio,
353		it87_gpio->io_base);
354
355	if (!request_region(it87_gpio->io_base, it87_gpio->io_size,
356							KBUILD_MODNAME))
357		return -EBUSY;
358
359	/* Set up aliases for the GPIO connection.
360	 *
361	 * ITE documentation for recent chips such as the IT8728F
362	 * refers to the GPIO lines as GPxy, with a coordinates system
363	 * where x is the GPIO group (starting from 1) and y is the
364	 * bit within the group.
365	 *
366	 * By creating these aliases, we make it easier to understand
367	 * to which GPIO pin we're referring to.
368	 */
369	labels = kcalloc(it87_gpio->chip.ngpio, sizeof("it87_gpXY"),
370								GFP_KERNEL);
371	labels_table = kcalloc(it87_gpio->chip.ngpio, sizeof(const char *),
372								GFP_KERNEL);
373
374	if (!labels || !labels_table) {
375		rc = -ENOMEM;
376		goto labels_free;
377	}
378
379	for (i = 0; i < it87_gpio->chip.ngpio; i++) {
380		char *label = &labels[i * sizeof("it87_gpXY")];
381
382		sprintf(label, "it87_gp%u%u", 1+(i/8), i%8);
383		labels_table[i] = label;
384	}
385
386	it87_gpio->chip.names = (const char *const*)labels_table;
387
388	rc = gpiochip_add_data(&it87_gpio->chip, it87_gpio);
389	if (rc)
390		goto labels_free;
391
392	return 0;
393
394labels_free:
395	kfree(labels_table);
396	kfree(labels);
397	release_region(it87_gpio->io_base, it87_gpio->io_size);
398	return rc;
399}
400
401static void __exit it87_gpio_exit(void)
402{
403	struct it87_gpio *it87_gpio = &it87_gpio_chip;
404
405	gpiochip_remove(&it87_gpio->chip);
406	release_region(it87_gpio->io_base, it87_gpio->io_size);
407	kfree(it87_gpio->chip.names[0]);
408	kfree(it87_gpio->chip.names);
409}
410
411module_init(it87_gpio_init);
412module_exit(it87_gpio_exit);
413
414MODULE_AUTHOR("Diego Elio Pettenò <flameeyes@flameeyes.eu>");
415MODULE_DESCRIPTION("GPIO interface for IT87xx Super I/O chips");
416MODULE_LICENSE("GPL");