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