blob: e8faf53f3875df488eaba35c7463de6a3f03bd29 [file] [log] [blame]
David Brownell15fae372008-02-04 22:28:24 -08001/*
Grant Likelyc103de22011-06-04 18:38:28 -06002 * Driver for pcf857x, pca857x, and pca967x I2C GPIO expanders
David Brownell15fae372008-02-04 22:28:24 -08003 *
4 * Copyright (C) 2007 David Brownell
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21#include <linux/kernel.h>
22#include <linux/slab.h>
H Hartley Sweetend120c172009-09-22 16:46:37 -070023#include <linux/gpio.h>
David Brownell15fae372008-02-04 22:28:24 -080024#include <linux/i2c.h>
25#include <linux/i2c/pcf857x.h>
Kuninori Morimoto6e20a0a2012-06-14 19:40:41 -070026#include <linux/interrupt.h>
27#include <linux/irq.h>
28#include <linux/irqdomain.h>
Paul Gortmakerbb207ef2011-07-03 13:38:09 -040029#include <linux/module.h>
Kuninori Morimoto6e20a0a2012-06-14 19:40:41 -070030#include <linux/spinlock.h>
31#include <linux/workqueue.h>
David Brownell15fae372008-02-04 22:28:24 -080032
David Brownell15fae372008-02-04 22:28:24 -080033
Jean Delvare3760f732008-04-29 23:11:40 +020034static const struct i2c_device_id pcf857x_id[] = {
35 { "pcf8574", 8 },
Wolfram Sang4ba2ccb2009-09-18 22:45:47 +020036 { "pcf8574a", 8 },
Jean Delvare3760f732008-04-29 23:11:40 +020037 { "pca8574", 8 },
38 { "pca9670", 8 },
39 { "pca9672", 8 },
40 { "pca9674", 8 },
41 { "pcf8575", 16 },
42 { "pca8575", 16 },
43 { "pca9671", 16 },
44 { "pca9673", 16 },
45 { "pca9675", 16 },
David Brownell1673ad52008-07-21 14:21:34 -070046 { "max7328", 8 },
47 { "max7329", 8 },
Nikolay Balandin02130492013-03-06 15:06:44 +040048 { "tca9554", 8 },
Jean Delvare3760f732008-04-29 23:11:40 +020049 { }
50};
51MODULE_DEVICE_TABLE(i2c, pcf857x_id);
52
David Brownell15fae372008-02-04 22:28:24 -080053/*
54 * The pcf857x, pca857x, and pca967x chips only expose one read and one
55 * write register. Writing a "one" bit (to match the reset state) lets
56 * that pin be used as an input; it's not an open-drain model, but acts
57 * a bit like one. This is described as "quasi-bidirectional"; read the
58 * chip documentation for details.
59 *
60 * Many other I2C GPIO expander chips (like the pca953x models) have
61 * more complex register models and more conventional circuitry using
62 * push/pull drivers. They often use the same 0x20..0x27 addresses as
63 * pcf857x parts, making the "legacy" I2C driver model problematic.
64 */
65struct pcf857x {
66 struct gpio_chip chip;
67 struct i2c_client *client;
David Brownell1673ad52008-07-21 14:21:34 -070068 struct mutex lock; /* protect 'out' */
Kuninori Morimoto6e20a0a2012-06-14 19:40:41 -070069 struct work_struct work; /* irq demux work */
70 struct irq_domain *irq_domain; /* for irq demux */
71 spinlock_t slock; /* protect irq demux */
David Brownell15fae372008-02-04 22:28:24 -080072 unsigned out; /* software latch */
Kuninori Morimoto6e20a0a2012-06-14 19:40:41 -070073 unsigned status; /* current status */
74 int irq; /* real irq number */
Kuninori Morimoto0c65ddd2012-06-13 21:58:08 -070075
76 int (*write)(struct i2c_client *client, unsigned data);
77 int (*read)(struct i2c_client *client);
David Brownell15fae372008-02-04 22:28:24 -080078};
79
80/*-------------------------------------------------------------------------*/
81
82/* Talk to 8-bit I/O expander */
83
Kuninori Morimoto0c65ddd2012-06-13 21:58:08 -070084static int i2c_write_le8(struct i2c_client *client, unsigned data)
David Brownell15fae372008-02-04 22:28:24 -080085{
Kuninori Morimoto0c65ddd2012-06-13 21:58:08 -070086 return i2c_smbus_write_byte(client, data);
David Brownell15fae372008-02-04 22:28:24 -080087}
88
Kuninori Morimoto0c65ddd2012-06-13 21:58:08 -070089static int i2c_read_le8(struct i2c_client *client)
David Brownell15fae372008-02-04 22:28:24 -080090{
Kuninori Morimoto0c65ddd2012-06-13 21:58:08 -070091 return (int)i2c_smbus_read_byte(client);
David Brownell15fae372008-02-04 22:28:24 -080092}
93
David Brownell15fae372008-02-04 22:28:24 -080094/* Talk to 16-bit I/O expander */
95
Kuninori Morimoto0c65ddd2012-06-13 21:58:08 -070096static int i2c_write_le16(struct i2c_client *client, unsigned word)
David Brownell15fae372008-02-04 22:28:24 -080097{
98 u8 buf[2] = { word & 0xff, word >> 8, };
99 int status;
100
101 status = i2c_master_send(client, buf, 2);
102 return (status < 0) ? status : 0;
103}
104
105static int i2c_read_le16(struct i2c_client *client)
106{
107 u8 buf[2];
108 int status;
109
110 status = i2c_master_recv(client, buf, 2);
111 if (status < 0)
112 return status;
113 return (buf[1] << 8) | buf[0];
114}
115
Kuninori Morimoto0c65ddd2012-06-13 21:58:08 -0700116/*-------------------------------------------------------------------------*/
117
118static int pcf857x_input(struct gpio_chip *chip, unsigned offset)
David Brownell15fae372008-02-04 22:28:24 -0800119{
120 struct pcf857x *gpio = container_of(chip, struct pcf857x, chip);
David Brownell1673ad52008-07-21 14:21:34 -0700121 int status;
David Brownell15fae372008-02-04 22:28:24 -0800122
David Brownell1673ad52008-07-21 14:21:34 -0700123 mutex_lock(&gpio->lock);
David Brownell15fae372008-02-04 22:28:24 -0800124 gpio->out |= (1 << offset);
Kuninori Morimoto0c65ddd2012-06-13 21:58:08 -0700125 status = gpio->write(gpio->client, gpio->out);
David Brownell1673ad52008-07-21 14:21:34 -0700126 mutex_unlock(&gpio->lock);
127
128 return status;
David Brownell15fae372008-02-04 22:28:24 -0800129}
130
Kuninori Morimoto0c65ddd2012-06-13 21:58:08 -0700131static int pcf857x_get(struct gpio_chip *chip, unsigned offset)
David Brownell15fae372008-02-04 22:28:24 -0800132{
133 struct pcf857x *gpio = container_of(chip, struct pcf857x, chip);
134 int value;
135
Kuninori Morimoto0c65ddd2012-06-13 21:58:08 -0700136 value = gpio->read(gpio->client);
David Brownell15fae372008-02-04 22:28:24 -0800137 return (value < 0) ? 0 : (value & (1 << offset));
138}
139
Kuninori Morimoto0c65ddd2012-06-13 21:58:08 -0700140static int pcf857x_output(struct gpio_chip *chip, unsigned offset, int value)
David Brownell15fae372008-02-04 22:28:24 -0800141{
142 struct pcf857x *gpio = container_of(chip, struct pcf857x, chip);
143 unsigned bit = 1 << offset;
David Brownell1673ad52008-07-21 14:21:34 -0700144 int status;
David Brownell15fae372008-02-04 22:28:24 -0800145
David Brownell1673ad52008-07-21 14:21:34 -0700146 mutex_lock(&gpio->lock);
David Brownell15fae372008-02-04 22:28:24 -0800147 if (value)
148 gpio->out |= bit;
149 else
150 gpio->out &= ~bit;
Kuninori Morimoto0c65ddd2012-06-13 21:58:08 -0700151 status = gpio->write(gpio->client, gpio->out);
David Brownell1673ad52008-07-21 14:21:34 -0700152 mutex_unlock(&gpio->lock);
153
154 return status;
David Brownell15fae372008-02-04 22:28:24 -0800155}
156
Kuninori Morimoto0c65ddd2012-06-13 21:58:08 -0700157static void pcf857x_set(struct gpio_chip *chip, unsigned offset, int value)
David Brownell15fae372008-02-04 22:28:24 -0800158{
Kuninori Morimoto0c65ddd2012-06-13 21:58:08 -0700159 pcf857x_output(chip, offset, value);
David Brownell15fae372008-02-04 22:28:24 -0800160}
161
162/*-------------------------------------------------------------------------*/
163
Kuninori Morimoto6e20a0a2012-06-14 19:40:41 -0700164static int pcf857x_to_irq(struct gpio_chip *chip, unsigned offset)
165{
166 struct pcf857x *gpio = container_of(chip, struct pcf857x, chip);
167
168 return irq_create_mapping(gpio->irq_domain, offset);
169}
170
171static void pcf857x_irq_demux_work(struct work_struct *work)
172{
173 struct pcf857x *gpio = container_of(work,
174 struct pcf857x,
175 work);
176 unsigned long change, i, status, flags;
177
178 status = gpio->read(gpio->client);
179
180 spin_lock_irqsave(&gpio->slock, flags);
181
182 change = gpio->status ^ status;
183 for_each_set_bit(i, &change, gpio->chip.ngpio)
184 generic_handle_irq(irq_find_mapping(gpio->irq_domain, i));
185 gpio->status = status;
186
187 spin_unlock_irqrestore(&gpio->slock, flags);
188}
189
190static irqreturn_t pcf857x_irq_demux(int irq, void *data)
191{
192 struct pcf857x *gpio = data;
193
194 /*
195 * pcf857x can't read/write data here,
196 * since i2c data access might go to sleep.
197 */
198 schedule_work(&gpio->work);
199
200 return IRQ_HANDLED;
201}
202
203static int pcf857x_irq_domain_map(struct irq_domain *domain, unsigned int virq,
204 irq_hw_number_t hw)
205{
206 irq_set_chip_and_handler(virq,
207 &dummy_irq_chip,
208 handle_level_irq);
209 return 0;
210}
211
212static struct irq_domain_ops pcf857x_irq_domain_ops = {
213 .map = pcf857x_irq_domain_map,
214};
215
216static void pcf857x_irq_domain_cleanup(struct pcf857x *gpio)
217{
218 if (gpio->irq_domain)
219 irq_domain_remove(gpio->irq_domain);
220
221 if (gpio->irq)
222 free_irq(gpio->irq, gpio);
223}
224
225static int pcf857x_irq_domain_init(struct pcf857x *gpio,
226 struct pcf857x_platform_data *pdata,
Kuninori Morimoto805f8642012-12-06 01:10:28 -0800227 struct i2c_client *client)
Kuninori Morimoto6e20a0a2012-06-14 19:40:41 -0700228{
229 int status;
230
Kuninori Morimoto805f8642012-12-06 01:10:28 -0800231 gpio->irq_domain = irq_domain_add_linear(client->dev.of_node,
Kuninori Morimoto6e20a0a2012-06-14 19:40:41 -0700232 gpio->chip.ngpio,
233 &pcf857x_irq_domain_ops,
234 NULL);
235 if (!gpio->irq_domain)
236 goto fail;
237
238 /* enable real irq */
Kuninori Morimoto805f8642012-12-06 01:10:28 -0800239 status = request_irq(client->irq, pcf857x_irq_demux, 0,
240 dev_name(&client->dev), gpio);
Kuninori Morimoto6e20a0a2012-06-14 19:40:41 -0700241 if (status)
242 goto fail;
243
244 /* enable gpio_to_irq() */
245 INIT_WORK(&gpio->work, pcf857x_irq_demux_work);
246 gpio->chip.to_irq = pcf857x_to_irq;
Kuninori Morimoto805f8642012-12-06 01:10:28 -0800247 gpio->irq = client->irq;
Kuninori Morimoto6e20a0a2012-06-14 19:40:41 -0700248
249 return 0;
250
251fail:
252 pcf857x_irq_domain_cleanup(gpio);
253 return -EINVAL;
254}
255
256/*-------------------------------------------------------------------------*/
257
Jean Delvared2653e92008-04-29 23:11:39 +0200258static int pcf857x_probe(struct i2c_client *client,
259 const struct i2c_device_id *id)
David Brownell15fae372008-02-04 22:28:24 -0800260{
261 struct pcf857x_platform_data *pdata;
262 struct pcf857x *gpio;
263 int status;
264
265 pdata = client->dev.platform_data;
Ben Dooksa342d212009-01-15 13:50:45 -0800266 if (!pdata) {
267 dev_dbg(&client->dev, "no platform data\n");
Ben Dooksa342d212009-01-15 13:50:45 -0800268 }
David Brownell15fae372008-02-04 22:28:24 -0800269
270 /* Allocate, initialize, and register this gpio_chip. */
Jingoo Hanf39f54a2013-03-15 18:16:11 +0900271 gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL);
David Brownell15fae372008-02-04 22:28:24 -0800272 if (!gpio)
273 return -ENOMEM;
274
David Brownell1673ad52008-07-21 14:21:34 -0700275 mutex_init(&gpio->lock);
Kuninori Morimoto6e20a0a2012-06-14 19:40:41 -0700276 spin_lock_init(&gpio->slock);
David Brownell1673ad52008-07-21 14:21:34 -0700277
Kuninori Morimoto0c65ddd2012-06-13 21:58:08 -0700278 gpio->chip.base = pdata ? pdata->gpio_base : -1;
279 gpio->chip.can_sleep = 1;
280 gpio->chip.dev = &client->dev;
281 gpio->chip.owner = THIS_MODULE;
282 gpio->chip.get = pcf857x_get;
283 gpio->chip.set = pcf857x_set;
284 gpio->chip.direction_input = pcf857x_input;
285 gpio->chip.direction_output = pcf857x_output;
286 gpio->chip.ngpio = id->driver_data;
David Brownell15fae372008-02-04 22:28:24 -0800287
Kuninori Morimoto6e20a0a2012-06-14 19:40:41 -0700288 /* enable gpio_to_irq() if platform has settings */
Kuninori Morimoto805f8642012-12-06 01:10:28 -0800289 if (pdata && client->irq) {
290 status = pcf857x_irq_domain_init(gpio, pdata, client);
Kuninori Morimoto6e20a0a2012-06-14 19:40:41 -0700291 if (status < 0) {
292 dev_err(&client->dev, "irq_domain init failed\n");
293 goto fail;
294 }
295 }
296
David Brownell15fae372008-02-04 22:28:24 -0800297 /* NOTE: the OnSemi jlc1562b is also largely compatible with
298 * these parts, notably for output. It has a low-resolution
299 * DAC instead of pin change IRQs; and its inputs can be the
300 * result of comparators.
301 */
302
303 /* 8574 addresses are 0x20..0x27; 8574a uses 0x38..0x3f;
304 * 9670, 9672, 9764, and 9764a use quite a variety.
305 *
306 * NOTE: we don't distinguish here between *4 and *4a parts.
307 */
Jean Delvare3760f732008-04-29 23:11:40 +0200308 if (gpio->chip.ngpio == 8) {
Kuninori Morimoto0c65ddd2012-06-13 21:58:08 -0700309 gpio->write = i2c_write_le8;
310 gpio->read = i2c_read_le8;
David Brownell15fae372008-02-04 22:28:24 -0800311
312 if (!i2c_check_functionality(client->adapter,
313 I2C_FUNC_SMBUS_BYTE))
314 status = -EIO;
315
316 /* fail if there's no chip present */
317 else
318 status = i2c_smbus_read_byte(client);
319
320 /* '75/'75c addresses are 0x20..0x27, just like the '74;
321 * the '75c doesn't have a current source pulling high.
322 * 9671, 9673, and 9765 use quite a variety of addresses.
323 *
324 * NOTE: we don't distinguish here between '75 and '75c parts.
325 */
Jean Delvare3760f732008-04-29 23:11:40 +0200326 } else if (gpio->chip.ngpio == 16) {
Kuninori Morimoto0c65ddd2012-06-13 21:58:08 -0700327 gpio->write = i2c_write_le16;
328 gpio->read = i2c_read_le16;
David Brownell15fae372008-02-04 22:28:24 -0800329
330 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
331 status = -EIO;
332
333 /* fail if there's no chip present */
334 else
335 status = i2c_read_le16(client);
336
Ben Dooksa342d212009-01-15 13:50:45 -0800337 } else {
338 dev_dbg(&client->dev, "unsupported number of gpios\n");
339 status = -EINVAL;
340 }
David Brownell15fae372008-02-04 22:28:24 -0800341
342 if (status < 0)
343 goto fail;
344
345 gpio->chip.label = client->name;
346
347 gpio->client = client;
348 i2c_set_clientdata(client, gpio);
349
350 /* NOTE: these chips have strange "quasi-bidirectional" I/O pins.
351 * We can't actually know whether a pin is configured (a) as output
352 * and driving the signal low, or (b) as input and reporting a low
353 * value ... without knowing the last value written since the chip
354 * came out of reset (if any). We can't read the latched output.
355 *
356 * In short, the only reliable solution for setting up pin direction
357 * is to do it explicitly. The setup() method can do that, but it
358 * may cause transient glitching since it can't know the last value
359 * written (some pins may need to be driven low).
360 *
361 * Using pdata->n_latch avoids that trouble. When left initialized
362 * to zero, our software copy of the "latch" then matches the chip's
363 * all-ones reset state. Otherwise it flags pins to be driven low.
364 */
Dmitry Eremin-Solenikov49946f62010-08-10 18:02:24 -0700365 gpio->out = pdata ? ~pdata->n_latch : ~0;
Kuninori Morimoto6e20a0a2012-06-14 19:40:41 -0700366 gpio->status = gpio->out;
David Brownell15fae372008-02-04 22:28:24 -0800367
368 status = gpiochip_add(&gpio->chip);
369 if (status < 0)
370 goto fail;
371
David Brownell15fae372008-02-04 22:28:24 -0800372 /* Let platform code set up the GPIOs and their users.
373 * Now is the first time anyone could use them.
374 */
Dmitry Eremin-Solenikov49946f62010-08-10 18:02:24 -0700375 if (pdata && pdata->setup) {
David Brownell15fae372008-02-04 22:28:24 -0800376 status = pdata->setup(client,
377 gpio->chip.base, gpio->chip.ngpio,
378 pdata->context);
379 if (status < 0)
380 dev_warn(&client->dev, "setup --> %d\n", status);
381 }
382
Kuninori Morimoto805f8642012-12-06 01:10:28 -0800383 dev_info(&client->dev, "probed\n");
384
David Brownell15fae372008-02-04 22:28:24 -0800385 return 0;
386
387fail:
388 dev_dbg(&client->dev, "probe error %d for '%s'\n",
389 status, client->name);
Kuninori Morimoto6e20a0a2012-06-14 19:40:41 -0700390
Kuninori Morimoto805f8642012-12-06 01:10:28 -0800391 if (pdata && client->irq)
Kuninori Morimoto6e20a0a2012-06-14 19:40:41 -0700392 pcf857x_irq_domain_cleanup(gpio);
393
David Brownell15fae372008-02-04 22:28:24 -0800394 return status;
395}
396
397static int pcf857x_remove(struct i2c_client *client)
398{
399 struct pcf857x_platform_data *pdata = client->dev.platform_data;
400 struct pcf857x *gpio = i2c_get_clientdata(client);
401 int status = 0;
402
Dmitry Eremin-Solenikov49946f62010-08-10 18:02:24 -0700403 if (pdata && pdata->teardown) {
David Brownell15fae372008-02-04 22:28:24 -0800404 status = pdata->teardown(client,
405 gpio->chip.base, gpio->chip.ngpio,
406 pdata->context);
407 if (status < 0) {
408 dev_err(&client->dev, "%s --> %d\n",
409 "teardown", status);
410 return status;
411 }
412 }
413
Kuninori Morimoto805f8642012-12-06 01:10:28 -0800414 if (pdata && client->irq)
Kuninori Morimoto6e20a0a2012-06-14 19:40:41 -0700415 pcf857x_irq_domain_cleanup(gpio);
416
David Brownell15fae372008-02-04 22:28:24 -0800417 status = gpiochip_remove(&gpio->chip);
Jingoo Hanf39f54a2013-03-15 18:16:11 +0900418 if (status)
David Brownell15fae372008-02-04 22:28:24 -0800419 dev_err(&client->dev, "%s --> %d\n", "remove", status);
420 return status;
421}
422
423static struct i2c_driver pcf857x_driver = {
424 .driver = {
425 .name = "pcf857x",
426 .owner = THIS_MODULE,
427 },
428 .probe = pcf857x_probe,
429 .remove = pcf857x_remove,
Jean Delvare3760f732008-04-29 23:11:40 +0200430 .id_table = pcf857x_id,
David Brownell15fae372008-02-04 22:28:24 -0800431};
432
433static int __init pcf857x_init(void)
434{
435 return i2c_add_driver(&pcf857x_driver);
436}
David Brownell2f8d1192008-10-15 22:03:13 -0700437/* register after i2c postcore initcall and before
438 * subsys initcalls that may rely on these GPIOs
439 */
440subsys_initcall(pcf857x_init);
David Brownell15fae372008-02-04 22:28:24 -0800441
442static void __exit pcf857x_exit(void)
443{
444 i2c_del_driver(&pcf857x_driver);
445}
446module_exit(pcf857x_exit);
447
448MODULE_LICENSE("GPL");
449MODULE_AUTHOR("David Brownell");