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21#include <linux/gpio.h>
22#include <linux/i2c.h>
23#include <linux/i2c/pcf857x.h>
24#include <linux/interrupt.h>
25#include <linux/irq.h>
26#include <linux/irqdomain.h>
27#include <linux/kernel.h>
28#include <linux/module.h>
29#include <linux/of.h>
30#include <linux/of_device.h>
31#include <linux/slab.h>
32#include <linux/spinlock.h>
33
34
35static const struct i2c_device_id pcf857x_id[] = {
36 { "pcf8574", 8 },
37 { "pcf8574a", 8 },
38 { "pca8574", 8 },
39 { "pca9670", 8 },
40 { "pca9672", 8 },
41 { "pca9674", 8 },
42 { "pcf8575", 16 },
43 { "pca8575", 16 },
44 { "pca9671", 16 },
45 { "pca9673", 16 },
46 { "pca9675", 16 },
47 { "max7328", 8 },
48 { "max7329", 8 },
49 { "tca9554", 8 },
50 { }
51};
52MODULE_DEVICE_TABLE(i2c, pcf857x_id);
53
54#ifdef CONFIG_OF
55static const struct of_device_id pcf857x_of_table[] = {
56 { .compatible = "nxp,pcf8574" },
57 { .compatible = "nxp,pcf8574a" },
58 { .compatible = "nxp,pca8574" },
59 { .compatible = "nxp,pca9670" },
60 { .compatible = "nxp,pca9672" },
61 { .compatible = "nxp,pca9674" },
62 { .compatible = "nxp,pcf8575" },
63 { .compatible = "nxp,pca8575" },
64 { .compatible = "nxp,pca9671" },
65 { .compatible = "nxp,pca9673" },
66 { .compatible = "nxp,pca9675" },
67 { .compatible = "maxim,max7328" },
68 { .compatible = "maxim,max7329" },
69 { .compatible = "ti,tca9554" },
70 { }
71};
72MODULE_DEVICE_TABLE(of, pcf857x_of_table);
73#endif
74
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85
86
87struct pcf857x {
88 struct gpio_chip chip;
89 struct i2c_client *client;
90 struct mutex lock;
91 unsigned out;
92 unsigned status;
93 unsigned int irq_parent;
94 unsigned irq_enabled;
95
96 int (*write)(struct i2c_client *client, unsigned data);
97 int (*read)(struct i2c_client *client);
98};
99
100
101
102
103
104static int i2c_write_le8(struct i2c_client *client, unsigned data)
105{
106 return i2c_smbus_write_byte(client, data);
107}
108
109static int i2c_read_le8(struct i2c_client *client)
110{
111 return (int)i2c_smbus_read_byte(client);
112}
113
114
115
116static int i2c_write_le16(struct i2c_client *client, unsigned word)
117{
118 u8 buf[2] = { word & 0xff, word >> 8, };
119 int status;
120
121 status = i2c_master_send(client, buf, 2);
122 return (status < 0) ? status : 0;
123}
124
125static int i2c_read_le16(struct i2c_client *client)
126{
127 u8 buf[2];
128 int status;
129
130 status = i2c_master_recv(client, buf, 2);
131 if (status < 0)
132 return status;
133 return (buf[1] << 8) | buf[0];
134}
135
136
137
138static int pcf857x_input(struct gpio_chip *chip, unsigned offset)
139{
140 struct pcf857x *gpio = gpiochip_get_data(chip);
141 int status;
142
143 mutex_lock(&gpio->lock);
144 gpio->out |= (1 << offset);
145 status = gpio->write(gpio->client, gpio->out);
146 mutex_unlock(&gpio->lock);
147
148 return status;
149}
150
151static int pcf857x_get(struct gpio_chip *chip, unsigned offset)
152{
153 struct pcf857x *gpio = gpiochip_get_data(chip);
154 int value;
155
156 value = gpio->read(gpio->client);
157 return (value < 0) ? value : !!(value & (1 << offset));
158}
159
160static int pcf857x_output(struct gpio_chip *chip, unsigned offset, int value)
161{
162 struct pcf857x *gpio = gpiochip_get_data(chip);
163 unsigned bit = 1 << offset;
164 int status;
165
166 mutex_lock(&gpio->lock);
167 if (value)
168 gpio->out |= bit;
169 else
170 gpio->out &= ~bit;
171 status = gpio->write(gpio->client, gpio->out);
172 mutex_unlock(&gpio->lock);
173
174 return status;
175}
176
177static void pcf857x_set(struct gpio_chip *chip, unsigned offset, int value)
178{
179 pcf857x_output(chip, offset, value);
180}
181
182
183
184static irqreturn_t pcf857x_irq(int irq, void *data)
185{
186 struct pcf857x *gpio = data;
187 unsigned long change, i, status;
188
189 status = gpio->read(gpio->client);
190
191
192
193
194
195 mutex_lock(&gpio->lock);
196 change = (gpio->status ^ status) & gpio->irq_enabled;
197 gpio->status = status;
198 mutex_unlock(&gpio->lock);
199
200 for_each_set_bit(i, &change, gpio->chip.ngpio)
201 handle_nested_irq(irq_find_mapping(gpio->chip.irqdomain, i));
202
203 return IRQ_HANDLED;
204}
205
206
207
208
209static void noop(struct irq_data *data) { }
210
211static int pcf857x_irq_set_wake(struct irq_data *data, unsigned int on)
212{
213 struct pcf857x *gpio = irq_data_get_irq_chip_data(data);
214
215 int error = 0;
216
217 if (gpio->irq_parent) {
218 error = irq_set_irq_wake(gpio->irq_parent, on);
219 if (error) {
220 dev_dbg(&gpio->client->dev,
221 "irq %u doesn't support irq_set_wake\n",
222 gpio->irq_parent);
223 gpio->irq_parent = 0;
224 }
225 }
226 return error;
227}
228
229static void pcf857x_irq_enable(struct irq_data *data)
230{
231 struct pcf857x *gpio = irq_data_get_irq_chip_data(data);
232
233 gpio->irq_enabled |= (1 << data->hwirq);
234}
235
236static void pcf857x_irq_disable(struct irq_data *data)
237{
238 struct pcf857x *gpio = irq_data_get_irq_chip_data(data);
239
240 gpio->irq_enabled &= ~(1 << data->hwirq);
241}
242
243static void pcf857x_irq_bus_lock(struct irq_data *data)
244{
245 struct pcf857x *gpio = irq_data_get_irq_chip_data(data);
246
247 mutex_lock(&gpio->lock);
248}
249
250static void pcf857x_irq_bus_sync_unlock(struct irq_data *data)
251{
252 struct pcf857x *gpio = irq_data_get_irq_chip_data(data);
253
254 mutex_unlock(&gpio->lock);
255}
256
257static struct irq_chip pcf857x_irq_chip = {
258 .name = "pcf857x",
259 .irq_enable = pcf857x_irq_enable,
260 .irq_disable = pcf857x_irq_disable,
261 .irq_ack = noop,
262 .irq_mask = noop,
263 .irq_unmask = noop,
264 .irq_set_wake = pcf857x_irq_set_wake,
265 .irq_bus_lock = pcf857x_irq_bus_lock,
266 .irq_bus_sync_unlock = pcf857x_irq_bus_sync_unlock,
267};
268
269
270
271static int pcf857x_probe(struct i2c_client *client,
272 const struct i2c_device_id *id)
273{
274 struct pcf857x_platform_data *pdata = dev_get_platdata(&client->dev);
275 struct device_node *np = client->dev.of_node;
276 struct pcf857x *gpio;
277 unsigned int n_latch = 0;
278 int status;
279
280 if (IS_ENABLED(CONFIG_OF) && np)
281 of_property_read_u32(np, "lines-initial-states", &n_latch);
282 else if (pdata)
283 n_latch = pdata->n_latch;
284 else
285 dev_dbg(&client->dev, "no platform data\n");
286
287
288 gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL);
289 if (!gpio)
290 return -ENOMEM;
291
292 mutex_init(&gpio->lock);
293
294 gpio->chip.base = pdata ? pdata->gpio_base : -1;
295 gpio->chip.can_sleep = true;
296 gpio->chip.parent = &client->dev;
297 gpio->chip.owner = THIS_MODULE;
298 gpio->chip.get = pcf857x_get;
299 gpio->chip.set = pcf857x_set;
300 gpio->chip.direction_input = pcf857x_input;
301 gpio->chip.direction_output = pcf857x_output;
302 gpio->chip.ngpio = id->driver_data;
303
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312
313
314
315 if (gpio->chip.ngpio == 8) {
316 gpio->write = i2c_write_le8;
317 gpio->read = i2c_read_le8;
318
319 if (!i2c_check_functionality(client->adapter,
320 I2C_FUNC_SMBUS_BYTE))
321 status = -EIO;
322
323
324 else
325 status = i2c_smbus_read_byte(client);
326
327
328
329
330
331
332
333 } else if (gpio->chip.ngpio == 16) {
334 gpio->write = i2c_write_le16;
335 gpio->read = i2c_read_le16;
336
337 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
338 status = -EIO;
339
340
341 else
342 status = i2c_read_le16(client);
343
344 } else {
345 dev_dbg(&client->dev, "unsupported number of gpios\n");
346 status = -EINVAL;
347 }
348
349 if (status < 0)
350 goto fail;
351
352 gpio->chip.label = client->name;
353
354 gpio->client = client;
355 i2c_set_clientdata(client, gpio);
356
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370
371
372 gpio->out = ~n_latch;
373 gpio->status = gpio->out;
374
375 status = devm_gpiochip_add_data(&client->dev, &gpio->chip, gpio);
376 if (status < 0)
377 goto fail;
378
379
380 if (client->irq) {
381 status = gpiochip_irqchip_add(&gpio->chip, &pcf857x_irq_chip,
382 0, handle_level_irq,
383 IRQ_TYPE_NONE);
384 if (status) {
385 dev_err(&client->dev, "cannot add irqchip\n");
386 goto fail;
387 }
388
389 status = devm_request_threaded_irq(&client->dev, client->irq,
390 NULL, pcf857x_irq, IRQF_ONESHOT |
391 IRQF_TRIGGER_FALLING | IRQF_SHARED,
392 dev_name(&client->dev), gpio);
393 if (status)
394 goto fail;
395
396 gpiochip_set_chained_irqchip(&gpio->chip, &pcf857x_irq_chip,
397 client->irq, NULL);
398 gpio->irq_parent = client->irq;
399 }
400
401
402
403
404 if (pdata && pdata->setup) {
405 status = pdata->setup(client,
406 gpio->chip.base, gpio->chip.ngpio,
407 pdata->context);
408 if (status < 0)
409 dev_warn(&client->dev, "setup --> %d\n", status);
410 }
411
412 dev_info(&client->dev, "probed\n");
413
414 return 0;
415
416fail:
417 dev_dbg(&client->dev, "probe error %d for '%s'\n", status,
418 client->name);
419
420 return status;
421}
422
423static int pcf857x_remove(struct i2c_client *client)
424{
425 struct pcf857x_platform_data *pdata = dev_get_platdata(&client->dev);
426 struct pcf857x *gpio = i2c_get_clientdata(client);
427 int status = 0;
428
429 if (pdata && pdata->teardown) {
430 status = pdata->teardown(client,
431 gpio->chip.base, gpio->chip.ngpio,
432 pdata->context);
433 if (status < 0) {
434 dev_err(&client->dev, "%s --> %d\n",
435 "teardown", status);
436 return status;
437 }
438 }
439
440 return status;
441}
442
443static struct i2c_driver pcf857x_driver = {
444 .driver = {
445 .name = "pcf857x",
446 .of_match_table = of_match_ptr(pcf857x_of_table),
447 },
448 .probe = pcf857x_probe,
449 .remove = pcf857x_remove,
450 .id_table = pcf857x_id,
451};
452
453static int __init pcf857x_init(void)
454{
455 return i2c_add_driver(&pcf857x_driver);
456}
457
458
459
460subsys_initcall(pcf857x_init);
461
462static void __exit pcf857x_exit(void)
463{
464 i2c_del_driver(&pcf857x_driver);
465}
466module_exit(pcf857x_exit);
467
468MODULE_LICENSE("GPL");
469MODULE_AUTHOR("David Brownell");
470