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8#include <linux/gpio/driver.h>
9#include <linux/i2c.h>
10#include <linux/platform_data/pcf857x.h>
11#include <linux/interrupt.h>
12#include <linux/irq.h>
13#include <linux/irqdomain.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/of.h>
17#include <linux/of_device.h>
18#include <linux/slab.h>
19#include <linux/spinlock.h>
20
21
22static const struct i2c_device_id pcf857x_id[] = {
23 { "pcf8574", 8 },
24 { "pcf8574a", 8 },
25 { "pca8574", 8 },
26 { "pca9670", 8 },
27 { "pca9672", 8 },
28 { "pca9674", 8 },
29 { "pcf8575", 16 },
30 { "pca8575", 16 },
31 { "pca9671", 16 },
32 { "pca9673", 16 },
33 { "pca9675", 16 },
34 { "max7328", 8 },
35 { "max7329", 8 },
36 { }
37};
38MODULE_DEVICE_TABLE(i2c, pcf857x_id);
39
40#ifdef CONFIG_OF
41static const struct of_device_id pcf857x_of_table[] = {
42 { .compatible = "nxp,pcf8574" },
43 { .compatible = "nxp,pcf8574a" },
44 { .compatible = "nxp,pca8574" },
45 { .compatible = "nxp,pca9670" },
46 { .compatible = "nxp,pca9672" },
47 { .compatible = "nxp,pca9674" },
48 { .compatible = "nxp,pcf8575" },
49 { .compatible = "nxp,pca8575" },
50 { .compatible = "nxp,pca9671" },
51 { .compatible = "nxp,pca9673" },
52 { .compatible = "nxp,pca9675" },
53 { .compatible = "maxim,max7328" },
54 { .compatible = "maxim,max7329" },
55 { }
56};
57MODULE_DEVICE_TABLE(of, pcf857x_of_table);
58#endif
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71
72struct pcf857x {
73 struct gpio_chip chip;
74 struct irq_chip irqchip;
75 struct i2c_client *client;
76 struct mutex lock;
77 unsigned out;
78 unsigned status;
79 unsigned irq_enabled;
80
81 int (*write)(struct i2c_client *client, unsigned data);
82 int (*read)(struct i2c_client *client);
83};
84
85
86
87
88
89static int i2c_write_le8(struct i2c_client *client, unsigned data)
90{
91 return i2c_smbus_write_byte(client, data);
92}
93
94static int i2c_read_le8(struct i2c_client *client)
95{
96 return (int)i2c_smbus_read_byte(client);
97}
98
99
100
101static int i2c_write_le16(struct i2c_client *client, unsigned word)
102{
103 u8 buf[2] = { word & 0xff, word >> 8, };
104 int status;
105
106 status = i2c_master_send(client, buf, 2);
107 return (status < 0) ? status : 0;
108}
109
110static int i2c_read_le16(struct i2c_client *client)
111{
112 u8 buf[2];
113 int status;
114
115 status = i2c_master_recv(client, buf, 2);
116 if (status < 0)
117 return status;
118 return (buf[1] << 8) | buf[0];
119}
120
121
122
123static int pcf857x_input(struct gpio_chip *chip, unsigned offset)
124{
125 struct pcf857x *gpio = gpiochip_get_data(chip);
126 int status;
127
128 mutex_lock(&gpio->lock);
129 gpio->out |= (1 << offset);
130 status = gpio->write(gpio->client, gpio->out);
131 mutex_unlock(&gpio->lock);
132
133 return status;
134}
135
136static int pcf857x_get(struct gpio_chip *chip, unsigned offset)
137{
138 struct pcf857x *gpio = gpiochip_get_data(chip);
139 int value;
140
141 value = gpio->read(gpio->client);
142 return (value < 0) ? value : !!(value & (1 << offset));
143}
144
145static int pcf857x_output(struct gpio_chip *chip, unsigned offset, int value)
146{
147 struct pcf857x *gpio = gpiochip_get_data(chip);
148 unsigned bit = 1 << offset;
149 int status;
150
151 mutex_lock(&gpio->lock);
152 if (value)
153 gpio->out |= bit;
154 else
155 gpio->out &= ~bit;
156 status = gpio->write(gpio->client, gpio->out);
157 mutex_unlock(&gpio->lock);
158
159 return status;
160}
161
162static void pcf857x_set(struct gpio_chip *chip, unsigned offset, int value)
163{
164 pcf857x_output(chip, offset, value);
165}
166
167
168
169static irqreturn_t pcf857x_irq(int irq, void *data)
170{
171 struct pcf857x *gpio = data;
172 unsigned long change, i, status;
173
174 status = gpio->read(gpio->client);
175
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179
180 mutex_lock(&gpio->lock);
181 change = (gpio->status ^ status) & gpio->irq_enabled;
182 gpio->status = status;
183 mutex_unlock(&gpio->lock);
184
185 for_each_set_bit(i, &change, gpio->chip.ngpio)
186 handle_nested_irq(irq_find_mapping(gpio->chip.irq.domain, i));
187
188 return IRQ_HANDLED;
189}
190
191
192
193
194static void noop(struct irq_data *data) { }
195
196static int pcf857x_irq_set_wake(struct irq_data *data, unsigned int on)
197{
198 struct pcf857x *gpio = irq_data_get_irq_chip_data(data);
199
200 return irq_set_irq_wake(gpio->client->irq, on);
201}
202
203static void pcf857x_irq_enable(struct irq_data *data)
204{
205 struct pcf857x *gpio = irq_data_get_irq_chip_data(data);
206
207 gpio->irq_enabled |= (1 << data->hwirq);
208}
209
210static void pcf857x_irq_disable(struct irq_data *data)
211{
212 struct pcf857x *gpio = irq_data_get_irq_chip_data(data);
213
214 gpio->irq_enabled &= ~(1 << data->hwirq);
215}
216
217static void pcf857x_irq_bus_lock(struct irq_data *data)
218{
219 struct pcf857x *gpio = irq_data_get_irq_chip_data(data);
220
221 mutex_lock(&gpio->lock);
222}
223
224static void pcf857x_irq_bus_sync_unlock(struct irq_data *data)
225{
226 struct pcf857x *gpio = irq_data_get_irq_chip_data(data);
227
228 mutex_unlock(&gpio->lock);
229}
230
231
232
233static int pcf857x_probe(struct i2c_client *client,
234 const struct i2c_device_id *id)
235{
236 struct pcf857x_platform_data *pdata = dev_get_platdata(&client->dev);
237 struct device_node *np = client->dev.of_node;
238 struct pcf857x *gpio;
239 unsigned int n_latch = 0;
240 int status;
241
242 if (IS_ENABLED(CONFIG_OF) && np)
243 of_property_read_u32(np, "lines-initial-states", &n_latch);
244 else if (pdata)
245 n_latch = pdata->n_latch;
246 else
247 dev_dbg(&client->dev, "no platform data\n");
248
249
250 gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL);
251 if (!gpio)
252 return -ENOMEM;
253
254 mutex_init(&gpio->lock);
255
256 gpio->chip.base = pdata ? pdata->gpio_base : -1;
257 gpio->chip.can_sleep = true;
258 gpio->chip.parent = &client->dev;
259 gpio->chip.owner = THIS_MODULE;
260 gpio->chip.get = pcf857x_get;
261 gpio->chip.set = pcf857x_set;
262 gpio->chip.direction_input = pcf857x_input;
263 gpio->chip.direction_output = pcf857x_output;
264 gpio->chip.ngpio = id->driver_data;
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277 if (gpio->chip.ngpio == 8) {
278 gpio->write = i2c_write_le8;
279 gpio->read = i2c_read_le8;
280
281 if (!i2c_check_functionality(client->adapter,
282 I2C_FUNC_SMBUS_BYTE))
283 status = -EIO;
284
285
286 else
287 status = i2c_smbus_read_byte(client);
288
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291
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293
294
295 } else if (gpio->chip.ngpio == 16) {
296 gpio->write = i2c_write_le16;
297 gpio->read = i2c_read_le16;
298
299 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
300 status = -EIO;
301
302
303 else
304 status = i2c_read_le16(client);
305
306 } else {
307 dev_dbg(&client->dev, "unsupported number of gpios\n");
308 status = -EINVAL;
309 }
310
311 if (status < 0)
312 goto fail;
313
314 gpio->chip.label = client->name;
315
316 gpio->client = client;
317 i2c_set_clientdata(client, gpio);
318
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334 gpio->out = ~n_latch;
335 gpio->status = gpio->out;
336
337 status = devm_gpiochip_add_data(&client->dev, &gpio->chip, gpio);
338 if (status < 0)
339 goto fail;
340
341
342 if (client->irq) {
343 gpio->irqchip.name = "pcf857x",
344 gpio->irqchip.irq_enable = pcf857x_irq_enable,
345 gpio->irqchip.irq_disable = pcf857x_irq_disable,
346 gpio->irqchip.irq_ack = noop,
347 gpio->irqchip.irq_mask = noop,
348 gpio->irqchip.irq_unmask = noop,
349 gpio->irqchip.irq_set_wake = pcf857x_irq_set_wake,
350 gpio->irqchip.irq_bus_lock = pcf857x_irq_bus_lock,
351 gpio->irqchip.irq_bus_sync_unlock = pcf857x_irq_bus_sync_unlock,
352 status = gpiochip_irqchip_add_nested(&gpio->chip,
353 &gpio->irqchip,
354 0, handle_level_irq,
355 IRQ_TYPE_NONE);
356 if (status) {
357 dev_err(&client->dev, "cannot add irqchip\n");
358 goto fail;
359 }
360
361 status = devm_request_threaded_irq(&client->dev, client->irq,
362 NULL, pcf857x_irq, IRQF_ONESHOT |
363 IRQF_TRIGGER_FALLING | IRQF_SHARED,
364 dev_name(&client->dev), gpio);
365 if (status)
366 goto fail;
367
368 gpiochip_set_nested_irqchip(&gpio->chip, &gpio->irqchip,
369 client->irq);
370 }
371
372
373
374
375 if (pdata && pdata->setup) {
376 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
383 dev_info(&client->dev, "probed\n");
384
385 return 0;
386
387fail:
388 dev_dbg(&client->dev, "probe error %d for '%s'\n", status,
389 client->name);
390
391 return status;
392}
393
394static int pcf857x_remove(struct i2c_client *client)
395{
396 struct pcf857x_platform_data *pdata = dev_get_platdata(&client->dev);
397 struct pcf857x *gpio = i2c_get_clientdata(client);
398 int status = 0;
399
400 if (pdata && pdata->teardown) {
401 status = pdata->teardown(client,
402 gpio->chip.base, gpio->chip.ngpio,
403 pdata->context);
404 if (status < 0) {
405 dev_err(&client->dev, "%s --> %d\n",
406 "teardown", status);
407 return status;
408 }
409 }
410
411 return status;
412}
413
414static void pcf857x_shutdown(struct i2c_client *client)
415{
416 struct pcf857x *gpio = i2c_get_clientdata(client);
417
418
419 gpio->write(gpio->client, BIT(gpio->chip.ngpio) - 1);
420}
421
422static struct i2c_driver pcf857x_driver = {
423 .driver = {
424 .name = "pcf857x",
425 .of_match_table = of_match_ptr(pcf857x_of_table),
426 },
427 .probe = pcf857x_probe,
428 .remove = pcf857x_remove,
429 .shutdown = pcf857x_shutdown,
430 .id_table = pcf857x_id,
431};
432
433static int __init pcf857x_init(void)
434{
435 return i2c_add_driver(&pcf857x_driver);
436}
437
438
439
440subsys_initcall(pcf857x_init);
441
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");
450