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/driver.h>
16 #include <linux/interrupt.h>
17 #include <linux/irq.h>
18
19 #include <linux/platform_data/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 uint8_t int_input_en[3];
45 uint8_t int_lvl_cached[3];
46 };
47
adp5588_gpio_read(struct i2c_client * client,u8 reg)48 static int adp5588_gpio_read(struct i2c_client *client, u8 reg)
49 {
50 int ret = i2c_smbus_read_byte_data(client, reg);
51
52 if (ret < 0)
53 dev_err(&client->dev, "Read Error\n");
54
55 return ret;
56 }
57
adp5588_gpio_write(struct i2c_client * client,u8 reg,u8 val)58 static int adp5588_gpio_write(struct i2c_client *client, u8 reg, u8 val)
59 {
60 int ret = i2c_smbus_write_byte_data(client, reg, val);
61
62 if (ret < 0)
63 dev_err(&client->dev, "Write Error\n");
64
65 return ret;
66 }
67
adp5588_gpio_get_value(struct gpio_chip * chip,unsigned off)68 static int adp5588_gpio_get_value(struct gpio_chip *chip, unsigned off)
69 {
70 struct adp5588_gpio *dev = gpiochip_get_data(chip);
71 unsigned bank = ADP5588_BANK(off);
72 unsigned bit = ADP5588_BIT(off);
73 int val;
74
75 mutex_lock(&dev->lock);
76
77 if (dev->dir[bank] & bit)
78 val = dev->dat_out[bank];
79 else
80 val = adp5588_gpio_read(dev->client, GPIO_DAT_STAT1 + bank);
81
82 mutex_unlock(&dev->lock);
83
84 return !!(val & bit);
85 }
86
adp5588_gpio_set_value(struct gpio_chip * chip,unsigned off,int val)87 static void adp5588_gpio_set_value(struct gpio_chip *chip,
88 unsigned off, int val)
89 {
90 unsigned bank, bit;
91 struct adp5588_gpio *dev = gpiochip_get_data(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 = gpiochip_get_data(chip);
112
113 bank = ADP5588_BANK(off);
114
115 mutex_lock(&dev->lock);
116 dev->dir[bank] &= ~ADP5588_BIT(off);
117 ret = adp5588_gpio_write(dev->client, GPIO_DIR1 + bank, dev->dir[bank]);
118 mutex_unlock(&dev->lock);
119
120 return ret;
121 }
122
adp5588_gpio_direction_output(struct gpio_chip * chip,unsigned off,int val)123 static int adp5588_gpio_direction_output(struct gpio_chip *chip,
124 unsigned off, int val)
125 {
126 int ret;
127 unsigned bank, bit;
128 struct adp5588_gpio *dev = gpiochip_get_data(chip);
129
130 bank = ADP5588_BANK(off);
131 bit = ADP5588_BIT(off);
132
133 mutex_lock(&dev->lock);
134 dev->dir[bank] |= bit;
135
136 if (val)
137 dev->dat_out[bank] |= bit;
138 else
139 dev->dat_out[bank] &= ~bit;
140
141 ret = adp5588_gpio_write(dev->client, GPIO_DAT_OUT1 + bank,
142 dev->dat_out[bank]);
143 ret |= adp5588_gpio_write(dev->client, GPIO_DIR1 + bank,
144 dev->dir[bank]);
145 mutex_unlock(&dev->lock);
146
147 return ret;
148 }
149
150 #ifdef CONFIG_GPIO_ADP5588_IRQ
adp5588_gpio_to_irq(struct gpio_chip * chip,unsigned off)151 static int adp5588_gpio_to_irq(struct gpio_chip *chip, unsigned off)
152 {
153 struct adp5588_gpio *dev = gpiochip_get_data(chip);
154
155 return dev->irq_base + off;
156 }
157
adp5588_irq_bus_lock(struct irq_data * d)158 static void adp5588_irq_bus_lock(struct irq_data *d)
159 {
160 struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
161
162 mutex_lock(&dev->irq_lock);
163 }
164
165 /*
166 * genirq core code can issue chip->mask/unmask from atomic context.
167 * This doesn't work for slow busses where an access needs to sleep.
168 * bus_sync_unlock() is therefore called outside the atomic context,
169 * syncs the current irq mask state with the slow external controller
170 * and unlocks the bus.
171 */
172
adp5588_irq_bus_sync_unlock(struct irq_data * d)173 static void adp5588_irq_bus_sync_unlock(struct irq_data *d)
174 {
175 struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
176 int i;
177
178 for (i = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
179 if (dev->int_input_en[i]) {
180 mutex_lock(&dev->lock);
181 dev->dir[i] &= ~dev->int_input_en[i];
182 dev->int_input_en[i] = 0;
183 adp5588_gpio_write(dev->client, GPIO_DIR1 + i,
184 dev->dir[i]);
185 mutex_unlock(&dev->lock);
186 }
187
188 if (dev->int_lvl_cached[i] != dev->int_lvl[i]) {
189 dev->int_lvl_cached[i] = dev->int_lvl[i];
190 adp5588_gpio_write(dev->client, GPIO_INT_LVL1 + i,
191 dev->int_lvl[i]);
192 }
193
194 if (dev->int_en[i] ^ dev->irq_mask[i]) {
195 dev->int_en[i] = dev->irq_mask[i];
196 adp5588_gpio_write(dev->client, GPIO_INT_EN1 + i,
197 dev->int_en[i]);
198 }
199 }
200
201 mutex_unlock(&dev->irq_lock);
202 }
203
adp5588_irq_mask(struct irq_data * d)204 static void adp5588_irq_mask(struct irq_data *d)
205 {
206 struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
207 unsigned gpio = d->irq - dev->irq_base;
208
209 dev->irq_mask[ADP5588_BANK(gpio)] &= ~ADP5588_BIT(gpio);
210 }
211
adp5588_irq_unmask(struct irq_data * d)212 static void adp5588_irq_unmask(struct irq_data *d)
213 {
214 struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
215 unsigned gpio = d->irq - dev->irq_base;
216
217 dev->irq_mask[ADP5588_BANK(gpio)] |= ADP5588_BIT(gpio);
218 }
219
adp5588_irq_set_type(struct irq_data * d,unsigned int type)220 static int adp5588_irq_set_type(struct irq_data *d, unsigned int type)
221 {
222 struct adp5588_gpio *dev = irq_data_get_irq_chip_data(d);
223 uint16_t gpio = d->irq - dev->irq_base;
224 unsigned bank, bit;
225
226 if ((type & IRQ_TYPE_EDGE_BOTH)) {
227 dev_err(&dev->client->dev, "irq %d: unsupported type %d\n",
228 d->irq, type);
229 return -EINVAL;
230 }
231
232 bank = ADP5588_BANK(gpio);
233 bit = ADP5588_BIT(gpio);
234
235 if (type & IRQ_TYPE_LEVEL_HIGH)
236 dev->int_lvl[bank] |= bit;
237 else if (type & IRQ_TYPE_LEVEL_LOW)
238 dev->int_lvl[bank] &= ~bit;
239 else
240 return -EINVAL;
241
242 dev->int_input_en[bank] |= bit;
243
244 return 0;
245 }
246
247 static struct irq_chip adp5588_irq_chip = {
248 .name = "adp5588",
249 .irq_mask = adp5588_irq_mask,
250 .irq_unmask = adp5588_irq_unmask,
251 .irq_bus_lock = adp5588_irq_bus_lock,
252 .irq_bus_sync_unlock = adp5588_irq_bus_sync_unlock,
253 .irq_set_type = adp5588_irq_set_type,
254 };
255
adp5588_gpio_read_intstat(struct i2c_client * client,u8 * buf)256 static int adp5588_gpio_read_intstat(struct i2c_client *client, u8 *buf)
257 {
258 int ret = i2c_smbus_read_i2c_block_data(client, GPIO_INT_STAT1, 3, buf);
259
260 if (ret < 0)
261 dev_err(&client->dev, "Read INT_STAT Error\n");
262
263 return ret;
264 }
265
adp5588_irq_handler(int irq,void * devid)266 static irqreturn_t adp5588_irq_handler(int irq, void *devid)
267 {
268 struct adp5588_gpio *dev = devid;
269 unsigned status, bank, bit, pending;
270 int ret;
271 status = adp5588_gpio_read(dev->client, INT_STAT);
272
273 if (status & ADP5588_GPI_INT) {
274 ret = adp5588_gpio_read_intstat(dev->client, dev->irq_stat);
275 if (ret < 0)
276 memset(dev->irq_stat, 0, ARRAY_SIZE(dev->irq_stat));
277
278 for (bank = 0, bit = 0; bank <= ADP5588_BANK(ADP5588_MAXGPIO);
279 bank++, bit = 0) {
280 pending = dev->irq_stat[bank] & dev->irq_mask[bank];
281
282 while (pending) {
283 if (pending & (1 << bit)) {
284 handle_nested_irq(dev->irq_base +
285 (bank << 3) + bit);
286 pending &= ~(1 << bit);
287
288 }
289 bit++;
290 }
291 }
292 }
293
294 adp5588_gpio_write(dev->client, INT_STAT, status); /* Status is W1C */
295
296 return IRQ_HANDLED;
297 }
298
adp5588_irq_setup(struct adp5588_gpio * dev)299 static int adp5588_irq_setup(struct adp5588_gpio *dev)
300 {
301 struct i2c_client *client = dev->client;
302 struct adp5588_gpio_platform_data *pdata =
303 dev_get_platdata(&client->dev);
304 unsigned gpio;
305 int ret;
306
307 adp5588_gpio_write(client, CFG, ADP5588_AUTO_INC);
308 adp5588_gpio_write(client, INT_STAT, -1); /* status is W1C */
309 adp5588_gpio_read_intstat(client, dev->irq_stat); /* read to clear */
310
311 dev->irq_base = pdata->irq_base;
312 mutex_init(&dev->irq_lock);
313
314 for (gpio = 0; gpio < dev->gpio_chip.ngpio; gpio++) {
315 int irq = gpio + dev->irq_base;
316 irq_set_chip_data(irq, dev);
317 irq_set_chip_and_handler(irq, &adp5588_irq_chip,
318 handle_level_irq);
319 irq_set_nested_thread(irq, 1);
320 irq_modify_status(irq, IRQ_NOREQUEST, IRQ_NOPROBE);
321 }
322
323 ret = request_threaded_irq(client->irq,
324 NULL,
325 adp5588_irq_handler,
326 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
327 dev_name(&client->dev), dev);
328 if (ret) {
329 dev_err(&client->dev, "failed to request irq %d\n",
330 client->irq);
331 goto out;
332 }
333
334 dev->gpio_chip.to_irq = adp5588_gpio_to_irq;
335 adp5588_gpio_write(client, CFG,
336 ADP5588_AUTO_INC | ADP5588_INT_CFG | ADP5588_GPI_INT);
337
338 return 0;
339
340 out:
341 dev->irq_base = 0;
342 return ret;
343 }
344
adp5588_irq_teardown(struct adp5588_gpio * dev)345 static void adp5588_irq_teardown(struct adp5588_gpio *dev)
346 {
347 if (dev->irq_base)
348 free_irq(dev->client->irq, dev);
349 }
350
351 #else
adp5588_irq_setup(struct adp5588_gpio * dev)352 static int adp5588_irq_setup(struct adp5588_gpio *dev)
353 {
354 struct i2c_client *client = dev->client;
355 dev_warn(&client->dev, "interrupt support not compiled in\n");
356
357 return 0;
358 }
359
adp5588_irq_teardown(struct adp5588_gpio * dev)360 static void adp5588_irq_teardown(struct adp5588_gpio *dev)
361 {
362 }
363 #endif /* CONFIG_GPIO_ADP5588_IRQ */
364
adp5588_gpio_probe(struct i2c_client * client,const struct i2c_device_id * id)365 static int adp5588_gpio_probe(struct i2c_client *client,
366 const struct i2c_device_id *id)
367 {
368 struct adp5588_gpio_platform_data *pdata =
369 dev_get_platdata(&client->dev);
370 struct adp5588_gpio *dev;
371 struct gpio_chip *gc;
372 int ret, i, revid;
373
374 if (!pdata) {
375 dev_err(&client->dev, "missing platform data\n");
376 return -ENODEV;
377 }
378
379 if (!i2c_check_functionality(client->adapter,
380 I2C_FUNC_SMBUS_BYTE_DATA)) {
381 dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
382 return -EIO;
383 }
384
385 dev = devm_kzalloc(&client->dev, sizeof(*dev), GFP_KERNEL);
386 if (!dev)
387 return -ENOMEM;
388
389 dev->client = client;
390
391 gc = &dev->gpio_chip;
392 gc->direction_input = adp5588_gpio_direction_input;
393 gc->direction_output = adp5588_gpio_direction_output;
394 gc->get = adp5588_gpio_get_value;
395 gc->set = adp5588_gpio_set_value;
396 gc->can_sleep = true;
397
398 gc->base = pdata->gpio_start;
399 gc->ngpio = ADP5588_MAXGPIO;
400 gc->label = client->name;
401 gc->owner = THIS_MODULE;
402 gc->names = pdata->names;
403
404 mutex_init(&dev->lock);
405
406 ret = adp5588_gpio_read(dev->client, DEV_ID);
407 if (ret < 0)
408 goto err;
409
410 revid = ret & ADP5588_DEVICE_ID_MASK;
411
412 for (i = 0, ret = 0; i <= ADP5588_BANK(ADP5588_MAXGPIO); i++) {
413 dev->dat_out[i] = adp5588_gpio_read(client, GPIO_DAT_OUT1 + i);
414 dev->dir[i] = adp5588_gpio_read(client, GPIO_DIR1 + i);
415 ret |= adp5588_gpio_write(client, KP_GPIO1 + i, 0);
416 ret |= adp5588_gpio_write(client, GPIO_PULL1 + i,
417 (pdata->pullup_dis_mask >> (8 * i)) & 0xFF);
418 ret |= adp5588_gpio_write(client, GPIO_INT_EN1 + i, 0);
419 if (ret)
420 goto err;
421 }
422
423 if (pdata->irq_base) {
424 if (WA_DELAYED_READOUT_REVID(revid)) {
425 dev_warn(&client->dev, "GPIO int not supported\n");
426 } else {
427 ret = adp5588_irq_setup(dev);
428 if (ret)
429 goto err;
430 }
431 }
432
433 ret = devm_gpiochip_add_data(&client->dev, &dev->gpio_chip, dev);
434 if (ret)
435 goto err_irq;
436
437 dev_info(&client->dev, "IRQ Base: %d Rev.: %d\n",
438 pdata->irq_base, revid);
439
440 if (pdata->setup) {
441 ret = pdata->setup(client, gc->base, gc->ngpio, pdata->context);
442 if (ret < 0)
443 dev_warn(&client->dev, "setup failed, %d\n", ret);
444 }
445
446 i2c_set_clientdata(client, dev);
447
448 return 0;
449
450 err_irq:
451 adp5588_irq_teardown(dev);
452 err:
453 return ret;
454 }
455
adp5588_gpio_remove(struct i2c_client * client)456 static int adp5588_gpio_remove(struct i2c_client *client)
457 {
458 struct adp5588_gpio_platform_data *pdata =
459 dev_get_platdata(&client->dev);
460 struct adp5588_gpio *dev = i2c_get_clientdata(client);
461 int ret;
462
463 if (pdata->teardown) {
464 ret = pdata->teardown(client,
465 dev->gpio_chip.base, dev->gpio_chip.ngpio,
466 pdata->context);
467 if (ret < 0) {
468 dev_err(&client->dev, "teardown failed %d\n", ret);
469 return ret;
470 }
471 }
472
473 if (dev->irq_base)
474 free_irq(dev->client->irq, dev);
475
476 return 0;
477 }
478
479 static const struct i2c_device_id adp5588_gpio_id[] = {
480 {DRV_NAME, 0},
481 {}
482 };
483
484 MODULE_DEVICE_TABLE(i2c, adp5588_gpio_id);
485
486 static struct i2c_driver adp5588_gpio_driver = {
487 .driver = {
488 .name = DRV_NAME,
489 },
490 .probe = adp5588_gpio_probe,
491 .remove = adp5588_gpio_remove,
492 .id_table = adp5588_gpio_id,
493 };
494
495 module_i2c_driver(adp5588_gpio_driver);
496
497 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
498 MODULE_DESCRIPTION("GPIO ADP5588 Driver");
499 MODULE_LICENSE("GPL");
500