1 /*
2 * GPIO Chip driver for Analog Devices
3 * ADP5588/ADP5587 I/O Expander and QWERTY Keypad Controller
4 *
5 * Copyright 2009-2010 Analog Devices Inc.
6 *
7 * Licensed under the GPL-2 or later.
8 */
9
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <linux/init.h>
14 #include <linux/i2c.h>
15 #include <linux/gpio.h>
16 #include <linux/interrupt.h>
17 #include <linux/irq.h>
18
19 #include <linux/i2c/adp5588.h>
20
21 #define DRV_NAME "adp5588-gpio"
22
23 /*
24 * Early pre 4.0 Silicon required to delay readout by at least 25ms,
25 * since the Event Counter Register updated 25ms after the interrupt
26 * asserted.
27 */
28 #define WA_DELAYED_READOUT_REVID(rev) ((rev) < 4)
29
30 struct adp5588_gpio {
31 struct i2c_client *client;
32 struct gpio_chip gpio_chip;
33 struct mutex lock; /* protect cached dir, dat_out */
34 /* protect serialized access to the interrupt controller bus */
35 struct mutex irq_lock;
36 unsigned gpio_start;
37 unsigned irq_base;
38 uint8_t dat_out[3];
39 uint8_t dir[3];
40 uint8_t int_lvl[3];
41 uint8_t int_en[3];
42 uint8_t irq_mask[3];
43 uint8_t irq_stat[3];
44 };
45
adp5588_gpio_read(struct i2c_client * client,u8 reg)46 static int adp5588_gpio_read(struct i2c_client *client, u8 reg)
47 {
48 int ret = i2c_smbus_read_byte_data(client, reg);
49
50 if (ret < 0)
51 dev_err(&client->dev, "Read Error\n");
52
53 return ret;
54 }
55
adp5588_gpio_write(struct i2c_client * client,u8 reg,u8 val)56 static int adp5588_gpio_write(struct i2c_client *client, u8 reg, u8 val)
57 {
58 int ret = i2c_smbus_write_byte_data(client, reg, val);
59
60 if (ret < 0)
61 dev_err(&client->dev, "Write Error\n");
62
63 return ret;
64 }
65
adp5588_gpio_get_value(struct gpio_chip * chip,unsigned off)66 static int adp5588_gpio_get_value(struct gpio_chip *chip, unsigned off)
67 {
68 struct adp5588_gpio *dev =
69 container_of(chip, struct adp5588_gpio, gpio_chip);
70 unsigned bank = ADP5588_BANK(off);
71 unsigned bit = ADP5588_BIT(off);
72 int val;
73
74 mutex_lock(&dev->lock);
75
76 if (dev->dir[bank] & bit)
77 val = dev->dat_out[bank];
78 else
79 val = adp5588_gpio_read(dev->client, GPIO_DAT_STAT1 + bank);
80
81 mutex_unlock(&dev->lock);
82
83 return !!(val & bit);
84 }
85
adp5588_gpio_set_value(struct gpio_chip * chip,unsigned off,int val)86 static void adp5588_gpio_set_value(struct gpio_chip *chip,
87 unsigned off, int val)
88 {
89 unsigned bank, bit;
90 struct adp5588_gpio *dev =
91 container_of(chip, struct adp5588_gpio, gpio_chip);
92
93 bank = ADP5588_BANK(off);
94 bit = ADP5588_BIT(off);
95
96 mutex_lock(&dev->lock);
97 if (val)
98 dev->dat_out[bank] |= bit;
99 else
100 dev->dat_out[bank] &= ~bit;
101
102 adp5588_gpio_write(dev->client, GPIO_DAT_OUT1 + bank,
103 dev->dat_out[bank]);
104 mutex_unlock(&dev->lock);
105 }
106
adp5588_gpio_direction_input(struct gpio_chip * chip,unsigned off)107 static int adp5588_gpio_direction_input(struct gpio_chip *chip, unsigned off)
108 {
109 int ret;
110 unsigned bank;
111 struct adp5588_gpio *dev =
112 container_of(chip, struct adp5588_gpio, gpio_chip);
113
114 bank = ADP5588_BANK(off);
115
116 mutex_lock(&dev->lock);
117 dev->dir[bank] &= ~ADP5588_BIT(off);
118 ret = adp5588_gpio_write(dev->client, GPIO_DIR1 + bank, dev->dir[bank]);
119 mutex_unlock(&dev->lock);
120
121 return ret;
122 }
123
adp5588_gpio_direction_output(struct gpio_chip * chip,unsigned off,int val)124 static int adp5588_gpio_direction_output(struct gpio_chip *chip,
125 unsigned off, int val)
126 {
127 int ret;
128 unsigned bank, bit;
129 struct adp5588_gpio *dev =
130 container_of(chip, struct adp5588_gpio, gpio_chip);
131
132 bank = ADP5588_BANK(off);
133 bit = ADP5588_BIT(off);
134
135 mutex_lock(&dev->lock);
136 dev->dir[bank] |= bit;
137
138 if (val)
139 dev->dat_out[bank] |= bit;
140 else
141 dev->dat_out[bank] &= ~bit;
142
143 ret = adp5588_gpio_write(dev->client, GPIO_DAT_OUT1 + bank,
144 dev->dat_out[bank]);
145 ret |= adp5588_gpio_write(dev->client, GPIO_DIR1 + bank,
146 dev->dir[bank]);
147 mutex_unlock(&dev->lock);
148
149 return ret;
150 }
151
152 #ifdef CONFIG_GPIO_ADP5588_IRQ
adp5588_gpio_to_irq(struct gpio_chip * chip,unsigned off)153 static int adp5588_gpio_to_irq(struct gpio_chip *chip, unsigned off)
154 {
155 struct adp5588_gpio *dev =
156 container_of(chip, struct adp5588_gpio, gpio_chip);
157 return dev->irq_base + off;
158 }
159
adp5588_irq_bus_lock(struct irq_data * d)160 static void adp5588_irq_bus_lock(struct irq_data *d)
161 {
162 struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
163
164 mutex_lock(&dev->irq_lock);
165 }
166
167 /*
168 * genirq core code can issue chip->mask/unmask from atomic context.
169 * This doesn't work for slow busses where an access needs to sleep.
170 * bus_sync_unlock() is therefore called outside the atomic context,
171 * syncs the current irq mask state with the slow external controller
172 * and unlocks the bus.
173 */
174
adp5588_irq_bus_sync_unlock(struct irq_data * d)175 static void adp5588_irq_bus_sync_unlock(struct irq_data *d)
176 {
177 struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
178 int i;
179
180 for (i = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++)
181 if (dev->int_en[i] ^ dev->irq_mask[i]) {
182 dev->int_en[i] = dev->irq_mask[i];
183 adp5588_gpio_write(dev->client, GPIO_INT_EN1 + i,
184 dev->int_en[i]);
185 }
186
187 mutex_unlock(&dev->irq_lock);
188 }
189
adp5588_irq_mask(struct irq_data * d)190 static void adp5588_irq_mask(struct irq_data *d)
191 {
192 struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
193 unsigned gpio = d->irq - dev->irq_base;
194
195 dev->irq_mask[ADP5588_BANK(gpio)] &= ~ADP5588_BIT(gpio);
196 }
197
adp5588_irq_unmask(struct irq_data * d)198 static void adp5588_irq_unmask(struct irq_data *d)
199 {
200 struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
201 unsigned gpio = d->irq - dev->irq_base;
202
203 dev->irq_mask[ADP5588_BANK(gpio)] |= ADP5588_BIT(gpio);
204 }
205
adp5588_irq_set_type(struct irq_data * d,unsigned int type)206 static int adp5588_irq_set_type(struct irq_data *d, unsigned int type)
207 {
208 struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
209 uint16_t gpio = d->irq - dev->irq_base;
210 unsigned bank, bit;
211
212 if ((type & IRQ_TYPE_EDGE_BOTH)) {
213 dev_err(&dev->client->dev, "irq %d: unsupported type %d\n",
214 d->irq, type);
215 return -EINVAL;
216 }
217
218 bank = ADP5588_BANK(gpio);
219 bit = ADP5588_BIT(gpio);
220
221 if (type & IRQ_TYPE_LEVEL_HIGH)
222 dev->int_lvl[bank] |= bit;
223 else if (type & IRQ_TYPE_LEVEL_LOW)
224 dev->int_lvl[bank] &= ~bit;
225 else
226 return -EINVAL;
227
228 adp5588_gpio_direction_input(&dev->gpio_chip, gpio);
229 adp5588_gpio_write(dev->client, GPIO_INT_LVL1 + bank,
230 dev->int_lvl[bank]);
231
232 return 0;
233 }
234
235 static struct irq_chip adp5588_irq_chip = {
236 .name = "adp5588",
237 .irq_mask = adp5588_irq_mask,
238 .irq_unmask = adp5588_irq_unmask,
239 .irq_bus_lock = adp5588_irq_bus_lock,
240 .irq_bus_sync_unlock = adp5588_irq_bus_sync_unlock,
241 .irq_set_type = adp5588_irq_set_type,
242 };
243
adp5588_gpio_read_intstat(struct i2c_client * client,u8 * buf)244 static int adp5588_gpio_read_intstat(struct i2c_client *client, u8 *buf)
245 {
246 int ret = i2c_smbus_read_i2c_block_data(client, GPIO_INT_STAT1, 3, buf);
247
248 if (ret < 0)
249 dev_err(&client->dev, "Read INT_STAT Error\n");
250
251 return ret;
252 }
253
adp5588_irq_handler(int irq,void * devid)254 static irqreturn_t adp5588_irq_handler(int irq, void *devid)
255 {
256 struct adp5588_gpio *dev = devid;
257 unsigned status, bank, bit, pending;
258 int ret;
259 status = adp5588_gpio_read(dev->client, INT_STAT);
260
261 if (status & ADP5588_GPI_INT) {
262 ret = adp5588_gpio_read_intstat(dev->client, dev->irq_stat);
263 if (ret < 0)
264 memset(dev->irq_stat, 0, ARRAY_SIZE(dev->irq_stat));
265
266 for (bank = 0, bit = 0; bank <= ADP5588_BANK(ADP5588_MAXGPIO);
267 bank++, bit = 0) {
268 pending = dev->irq_stat[bank] & dev->irq_mask[bank];
269
270 while (pending) {
271 if (pending & (1 << bit)) {
272 handle_nested_irq(dev->irq_base +
273 (bank << 3) + bit);
274 pending &= ~(1 << bit);
275
276 }
277 bit++;
278 }
279 }
280 }
281
282 adp5588_gpio_write(dev->client, INT_STAT, status); /* Status is W1C */
283
284 return IRQ_HANDLED;
285 }
286
adp5588_irq_setup(struct adp5588_gpio * dev)287 static int adp5588_irq_setup(struct adp5588_gpio *dev)
288 {
289 struct i2c_client *client = dev->client;
290 struct adp5588_gpio_platform_data *pdata =
291 dev_get_platdata(&client->dev);
292 unsigned gpio;
293 int ret;
294
295 adp5588_gpio_write(client, CFG, ADP5588_AUTO_INC);
296 adp5588_gpio_write(client, INT_STAT, -1); /* status is W1C */
297 adp5588_gpio_read_intstat(client, dev->irq_stat); /* read to clear */
298
299 dev->irq_base = pdata->irq_base;
300 mutex_init(&dev->irq_lock);
301
302 for (gpio = 0; gpio < dev->gpio_chip.ngpio; gpio++) {
303 int irq = gpio + dev->irq_base;
304 irq_set_chip_data(irq, dev);
305 irq_set_chip_and_handler(irq, &adp5588_irq_chip,
306 handle_level_irq);
307 irq_set_nested_thread(irq, 1);
308 irq_modify_status(irq, IRQ_NOREQUEST, IRQ_NOPROBE);
309 }
310
311 ret = request_threaded_irq(client->irq,
312 NULL,
313 adp5588_irq_handler,
314 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
315 dev_name(&client->dev), dev);
316 if (ret) {
317 dev_err(&client->dev, "failed to request irq %d\n",
318 client->irq);
319 goto out;
320 }
321
322 dev->gpio_chip.to_irq = adp5588_gpio_to_irq;
323 adp5588_gpio_write(client, CFG,
324 ADP5588_AUTO_INC | ADP5588_INT_CFG | ADP5588_GPI_INT);
325
326 return 0;
327
328 out:
329 dev->irq_base = 0;
330 return ret;
331 }
332
adp5588_irq_teardown(struct adp5588_gpio * dev)333 static void adp5588_irq_teardown(struct adp5588_gpio *dev)
334 {
335 if (dev->irq_base)
336 free_irq(dev->client->irq, dev);
337 }
338
339 #else
adp5588_irq_setup(struct adp5588_gpio * dev)340 static int adp5588_irq_setup(struct adp5588_gpio *dev)
341 {
342 struct i2c_client *client = dev->client;
343 dev_warn(&client->dev, "interrupt support not compiled in\n");
344
345 return 0;
346 }
347
adp5588_irq_teardown(struct adp5588_gpio * dev)348 static void adp5588_irq_teardown(struct adp5588_gpio *dev)
349 {
350 }
351 #endif /* CONFIG_GPIO_ADP5588_IRQ */
352
adp5588_gpio_probe(struct i2c_client * client,const struct i2c_device_id * id)353 static int adp5588_gpio_probe(struct i2c_client *client,
354 const struct i2c_device_id *id)
355 {
356 struct adp5588_gpio_platform_data *pdata =
357 dev_get_platdata(&client->dev);
358 struct adp5588_gpio *dev;
359 struct gpio_chip *gc;
360 int ret, i, revid;
361
362 if (!pdata) {
363 dev_err(&client->dev, "missing platform data\n");
364 return -ENODEV;
365 }
366
367 if (!i2c_check_functionality(client->adapter,
368 I2C_FUNC_SMBUS_BYTE_DATA)) {
369 dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
370 return -EIO;
371 }
372
373 dev = devm_kzalloc(&client->dev, sizeof(*dev), GFP_KERNEL);
374 if (!dev)
375 return -ENOMEM;
376
377 dev->client = client;
378
379 gc = &dev->gpio_chip;
380 gc->direction_input = adp5588_gpio_direction_input;
381 gc->direction_output = adp5588_gpio_direction_output;
382 gc->get = adp5588_gpio_get_value;
383 gc->set = adp5588_gpio_set_value;
384 gc->can_sleep = true;
385
386 gc->base = pdata->gpio_start;
387 gc->ngpio = ADP5588_MAXGPIO;
388 gc->label = client->name;
389 gc->owner = THIS_MODULE;
390 gc->names = pdata->names;
391
392 mutex_init(&dev->lock);
393
394 ret = adp5588_gpio_read(dev->client, DEV_ID);
395 if (ret < 0)
396 goto err;
397
398 revid = ret & ADP5588_DEVICE_ID_MASK;
399
400 for (i = 0, ret = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
401 dev->dat_out[i] = adp5588_gpio_read(client, GPIO_DAT_OUT1 + i);
402 dev->dir[i] = adp5588_gpio_read(client, GPIO_DIR1 + i);
403 ret |= adp5588_gpio_write(client, KP_GPIO1 + i, 0);
404 ret |= adp5588_gpio_write(client, GPIO_PULL1 + i,
405 (pdata->pullup_dis_mask >> (8 * i)) & 0xFF);
406 ret |= adp5588_gpio_write(client, GPIO_INT_EN1 + i, 0);
407 if (ret)
408 goto err;
409 }
410
411 if (pdata->irq_base) {
412 if (WA_DELAYED_READOUT_REVID(revid)) {
413 dev_warn(&client->dev, "GPIO int not supported\n");
414 } else {
415 ret = adp5588_irq_setup(dev);
416 if (ret)
417 goto err;
418 }
419 }
420
421 ret = gpiochip_add(&dev->gpio_chip);
422 if (ret)
423 goto err_irq;
424
425 dev_info(&client->dev, "IRQ Base: %d Rev.: %d\n",
426 pdata->irq_base, revid);
427
428 if (pdata->setup) {
429 ret = pdata->setup(client, gc->base, gc->ngpio, pdata->context);
430 if (ret < 0)
431 dev_warn(&client->dev, "setup failed, %d\n", ret);
432 }
433
434 i2c_set_clientdata(client, dev);
435
436 return 0;
437
438 err_irq:
439 adp5588_irq_teardown(dev);
440 err:
441 return ret;
442 }
443
adp5588_gpio_remove(struct i2c_client * client)444 static int adp5588_gpio_remove(struct i2c_client *client)
445 {
446 struct adp5588_gpio_platform_data *pdata =
447 dev_get_platdata(&client->dev);
448 struct adp5588_gpio *dev = i2c_get_clientdata(client);
449 int ret;
450
451 if (pdata->teardown) {
452 ret = pdata->teardown(client,
453 dev->gpio_chip.base, dev->gpio_chip.ngpio,
454 pdata->context);
455 if (ret < 0) {
456 dev_err(&client->dev, "teardown failed %d\n", ret);
457 return ret;
458 }
459 }
460
461 if (dev->irq_base)
462 free_irq(dev->client->irq, dev);
463
464 gpiochip_remove(&dev->gpio_chip);
465
466 return 0;
467 }
468
469 static const struct i2c_device_id adp5588_gpio_id[] = {
470 {DRV_NAME, 0},
471 {}
472 };
473
474 MODULE_DEVICE_TABLE(i2c, adp5588_gpio_id);
475
476 static struct i2c_driver adp5588_gpio_driver = {
477 .driver = {
478 .name = DRV_NAME,
479 },
480 .probe = adp5588_gpio_probe,
481 .remove = adp5588_gpio_remove,
482 .id_table = adp5588_gpio_id,
483 };
484
485 module_i2c_driver(adp5588_gpio_driver);
486
487 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
488 MODULE_DESCRIPTION("GPIO ADP5588 Driver");
489 MODULE_LICENSE("GPL");
490