1 /* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License version 2 and
5 * only version 2 as published by the Free Software Foundation.
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, write to the Free Software
14 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17 #include <linux/gpio.h>
18 #include <linux/i2c.h>
19 #include <linux/init.h>
20 #include <linux/interrupt.h>
21 #include <linux/irq.h>
22 #include <linux/module.h>
23 #include <linux/mutex.h>
24 #include <linux/slab.h>
25 #include <linux/workqueue.h>
26 #include <linux/i2c/sx150x.h>
28 #define NO_UPDATE_PENDING -1
30 struct sx150x_device_data {
47 struct gpio_chip gpio_chip;
48 struct i2c_client *client;
49 const struct sx150x_device_data *dev_cfg;
57 struct irq_chip irq_chip;
61 static const struct sx150x_device_data sx150x_devices[] = {
94 static const struct i2c_device_id sx150x_id[] = {
99 MODULE_DEVICE_TABLE(i2c, sx150x_id);
101 static s32 sx150x_i2c_write(struct i2c_client *client, u8 reg, u8 val)
103 s32 err = i2c_smbus_write_byte_data(client, reg, val);
106 dev_warn(&client->dev,
107 "i2c write fail: can't write %02x to %02x: %d\n",
112 static s32 sx150x_i2c_read(struct i2c_client *client, u8 reg, u8 *val)
114 s32 err = i2c_smbus_read_byte_data(client, reg);
119 dev_warn(&client->dev,
120 "i2c read fail: can't read from %02x: %d\n",
125 static inline bool offset_is_oscio(struct sx150x_chip *chip, unsigned offset)
127 return (chip->dev_cfg->ngpios == offset);
131 * These utility functions solve the common problem of locating and setting
132 * configuration bits. Configuration bits are grouped into registers
133 * whose indexes increase downwards. For example, with eight-bit registers,
134 * sixteen gpios would have their config bits grouped in the following order:
135 * REGISTER N-1 [ f e d c b a 9 8 ]
136 * N [ 7 6 5 4 3 2 1 0 ]
138 * For multi-bit configurations, the pattern gets wider:
139 * REGISTER N-3 [ f f e e d d c c ]
140 * N-2 [ b b a a 9 9 8 8 ]
141 * N-1 [ 7 7 6 6 5 5 4 4 ]
142 * N [ 3 3 2 2 1 1 0 0 ]
144 * Given the address of the starting register 'N', the index of the gpio
145 * whose configuration we seek to change, and the width in bits of that
146 * configuration, these functions allow us to locate the correct
147 * register and mask the correct bits.
149 static inline void sx150x_find_cfg(u8 offset, u8 width,
150 u8 *reg, u8 *mask, u8 *shift)
152 *reg -= offset * width / 8;
153 *mask = (1 << width) - 1;
154 *shift = (offset * width) % 8;
158 static s32 sx150x_write_cfg(struct sx150x_chip *chip,
159 u8 offset, u8 width, u8 reg, u8 val)
166 sx150x_find_cfg(offset, width, ®, &mask, &shift);
167 err = sx150x_i2c_read(chip->client, reg, &data);
172 data |= (val << shift) & mask;
173 return sx150x_i2c_write(chip->client, reg, data);
176 static int sx150x_get_io(struct sx150x_chip *chip, unsigned offset)
178 u8 reg = chip->dev_cfg->reg_data;
184 sx150x_find_cfg(offset, 1, ®, &mask, &shift);
185 err = sx150x_i2c_read(chip->client, reg, &data);
187 err = (data & mask) != 0 ? 1 : 0;
192 static void sx150x_set_oscio(struct sx150x_chip *chip, int val)
194 sx150x_i2c_write(chip->client,
195 chip->dev_cfg->reg_clock,
196 (val ? 0x1f : 0x10));
199 static void sx150x_set_io(struct sx150x_chip *chip, unsigned offset, int val)
201 sx150x_write_cfg(chip,
204 chip->dev_cfg->reg_data,
208 static int sx150x_io_input(struct sx150x_chip *chip, unsigned offset)
210 return sx150x_write_cfg(chip,
213 chip->dev_cfg->reg_dir,
217 static int sx150x_io_output(struct sx150x_chip *chip, unsigned offset, int val)
221 err = sx150x_write_cfg(chip,
224 chip->dev_cfg->reg_data,
227 err = sx150x_write_cfg(chip,
230 chip->dev_cfg->reg_dir,
235 static int sx150x_gpio_get(struct gpio_chip *gc, unsigned offset)
237 struct sx150x_chip *chip;
238 int status = -EINVAL;
240 chip = container_of(gc, struct sx150x_chip, gpio_chip);
242 if (!offset_is_oscio(chip, offset)) {
243 mutex_lock(&chip->lock);
244 status = sx150x_get_io(chip, offset);
245 mutex_unlock(&chip->lock);
251 static void sx150x_gpio_set(struct gpio_chip *gc, unsigned offset, int val)
253 struct sx150x_chip *chip;
255 chip = container_of(gc, struct sx150x_chip, gpio_chip);
257 mutex_lock(&chip->lock);
258 if (offset_is_oscio(chip, offset))
259 sx150x_set_oscio(chip, val);
261 sx150x_set_io(chip, offset, val);
262 mutex_unlock(&chip->lock);
265 static int sx150x_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
267 struct sx150x_chip *chip;
268 int status = -EINVAL;
270 chip = container_of(gc, struct sx150x_chip, gpio_chip);
272 if (!offset_is_oscio(chip, offset)) {
273 mutex_lock(&chip->lock);
274 status = sx150x_io_input(chip, offset);
275 mutex_unlock(&chip->lock);
280 static int sx150x_gpio_direction_output(struct gpio_chip *gc,
284 struct sx150x_chip *chip;
287 chip = container_of(gc, struct sx150x_chip, gpio_chip);
289 if (!offset_is_oscio(chip, offset)) {
290 mutex_lock(&chip->lock);
291 status = sx150x_io_output(chip, offset, val);
292 mutex_unlock(&chip->lock);
297 static int sx150x_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
299 struct sx150x_chip *chip;
301 chip = container_of(gc, struct sx150x_chip, gpio_chip);
303 if (offset >= chip->dev_cfg->ngpios)
306 if (chip->irq_base < 0)
309 return chip->irq_base + offset;
312 static void sx150x_irq_mask(struct irq_data *d)
314 struct irq_chip *ic = irq_data_get_irq_chip(d);
315 struct sx150x_chip *chip;
318 chip = container_of(ic, struct sx150x_chip, irq_chip);
319 n = d->irq - chip->irq_base;
320 chip->irq_masked |= (1 << n);
321 chip->irq_update = n;
324 static void sx150x_irq_unmask(struct irq_data *d)
326 struct irq_chip *ic = irq_data_get_irq_chip(d);
327 struct sx150x_chip *chip;
330 chip = container_of(ic, struct sx150x_chip, irq_chip);
331 n = d->irq - chip->irq_base;
333 chip->irq_masked &= ~(1 << n);
334 chip->irq_update = n;
337 static int sx150x_irq_set_type(struct irq_data *d, unsigned int flow_type)
339 struct irq_chip *ic = irq_data_get_irq_chip(d);
340 struct sx150x_chip *chip;
343 if (flow_type & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW))
346 chip = container_of(ic, struct sx150x_chip, irq_chip);
347 n = d->irq - chip->irq_base;
349 if (flow_type & IRQ_TYPE_EDGE_RISING)
351 if (flow_type & IRQ_TYPE_EDGE_FALLING)
354 chip->irq_sense &= ~(3UL << (n * 2));
355 chip->irq_sense |= val << (n * 2);
356 chip->irq_update = n;
360 static irqreturn_t sx150x_irq_thread_fn(int irq, void *dev_id)
362 struct sx150x_chip *chip = (struct sx150x_chip *)dev_id;
363 unsigned nhandled = 0;
370 for (i = (chip->dev_cfg->ngpios / 8) - 1; i >= 0; --i) {
371 err = sx150x_i2c_read(chip->client,
372 chip->dev_cfg->reg_irq_src - i,
377 sx150x_i2c_write(chip->client,
378 chip->dev_cfg->reg_irq_src - i,
380 for (n = 0; n < 8; ++n) {
381 if (val & (1 << n)) {
382 sub_irq = chip->irq_base + (i * 8) + n;
383 handle_nested_irq(sub_irq);
389 return (nhandled > 0 ? IRQ_HANDLED : IRQ_NONE);
392 static void sx150x_irq_bus_lock(struct irq_data *d)
394 struct irq_chip *ic = irq_data_get_irq_chip(d);
395 struct sx150x_chip *chip;
397 chip = container_of(ic, struct sx150x_chip, irq_chip);
399 mutex_lock(&chip->lock);
402 static void sx150x_irq_bus_sync_unlock(struct irq_data *d)
404 struct irq_chip *ic = irq_data_get_irq_chip(d);
405 struct sx150x_chip *chip;
408 chip = container_of(ic, struct sx150x_chip, irq_chip);
410 if (chip->irq_update == NO_UPDATE_PENDING)
413 n = chip->irq_update;
414 chip->irq_update = NO_UPDATE_PENDING;
416 /* Avoid updates if nothing changed */
417 if (chip->dev_sense == chip->irq_sense &&
418 chip->dev_sense == chip->irq_masked)
421 chip->dev_sense = chip->irq_sense;
422 chip->dev_masked = chip->irq_masked;
424 if (chip->irq_masked & (1 << n)) {
425 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 1);
426 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense, 0);
428 sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 0);
429 sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense,
430 chip->irq_sense >> (n * 2));
433 mutex_unlock(&chip->lock);
436 static void sx150x_init_chip(struct sx150x_chip *chip,
437 struct i2c_client *client,
438 kernel_ulong_t driver_data,
439 struct sx150x_platform_data *pdata)
441 mutex_init(&chip->lock);
443 chip->client = client;
444 chip->dev_cfg = &sx150x_devices[driver_data];
445 chip->gpio_chip.label = client->name;
446 chip->gpio_chip.direction_input = sx150x_gpio_direction_input;
447 chip->gpio_chip.direction_output = sx150x_gpio_direction_output;
448 chip->gpio_chip.get = sx150x_gpio_get;
449 chip->gpio_chip.set = sx150x_gpio_set;
450 chip->gpio_chip.to_irq = sx150x_gpio_to_irq;
451 chip->gpio_chip.base = pdata->gpio_base;
452 chip->gpio_chip.can_sleep = 1;
453 chip->gpio_chip.ngpio = chip->dev_cfg->ngpios;
454 if (pdata->oscio_is_gpo)
455 ++chip->gpio_chip.ngpio;
457 chip->irq_chip.name = client->name;
458 chip->irq_chip.irq_mask = sx150x_irq_mask;
459 chip->irq_chip.irq_unmask = sx150x_irq_unmask;
460 chip->irq_chip.irq_set_type = sx150x_irq_set_type;
461 chip->irq_chip.irq_bus_lock = sx150x_irq_bus_lock;
462 chip->irq_chip.irq_bus_sync_unlock = sx150x_irq_bus_sync_unlock;
463 chip->irq_summary = -1;
465 chip->irq_masked = ~0;
467 chip->dev_masked = ~0;
469 chip->irq_update = NO_UPDATE_PENDING;
472 static int sx150x_init_io(struct sx150x_chip *chip, u8 base, u16 cfg)
477 for (n = 0; err >= 0 && n < (chip->dev_cfg->ngpios / 8); ++n)
478 err = sx150x_i2c_write(chip->client, base - n, cfg >> (n * 8));
482 static int sx150x_reset(struct sx150x_chip *chip)
486 err = i2c_smbus_write_byte_data(chip->client,
487 chip->dev_cfg->reg_reset,
492 err = i2c_smbus_write_byte_data(chip->client,
493 chip->dev_cfg->reg_reset,
498 static int sx150x_init_hw(struct sx150x_chip *chip,
499 struct sx150x_platform_data *pdata)
503 if (pdata->reset_during_probe) {
504 err = sx150x_reset(chip);
509 err = sx150x_i2c_write(chip->client,
510 chip->dev_cfg->reg_misc,
515 err = sx150x_init_io(chip, chip->dev_cfg->reg_pullup,
516 pdata->io_pullup_ena);
520 err = sx150x_init_io(chip, chip->dev_cfg->reg_pulldn,
521 pdata->io_pulldn_ena);
525 err = sx150x_init_io(chip, chip->dev_cfg->reg_drain,
526 pdata->io_open_drain_ena);
530 err = sx150x_init_io(chip, chip->dev_cfg->reg_polarity,
535 if (pdata->oscio_is_gpo)
536 sx150x_set_oscio(chip, 0);
541 static int sx150x_install_irq_chip(struct sx150x_chip *chip,
549 chip->irq_summary = irq_summary;
550 chip->irq_base = irq_base;
552 for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
554 irq_set_chip_and_handler(irq, &chip->irq_chip, handle_edge_irq);
555 irq_set_nested_thread(irq, 1);
557 set_irq_flags(irq, IRQF_VALID);
559 irq_set_noprobe(irq);
563 err = request_threaded_irq(irq_summary,
565 sx150x_irq_thread_fn,
566 IRQF_SHARED | IRQF_TRIGGER_FALLING,
570 chip->irq_summary = -1;
577 static void sx150x_remove_irq_chip(struct sx150x_chip *chip)
582 free_irq(chip->irq_summary, chip);
584 for (n = 0; n < chip->dev_cfg->ngpios; ++n) {
585 irq = chip->irq_base + n;
586 irq_set_handler(irq, NULL);
587 irq_set_chip(irq, NULL);
591 static int __devinit sx150x_probe(struct i2c_client *client,
592 const struct i2c_device_id *id)
594 static const u32 i2c_funcs = I2C_FUNC_SMBUS_BYTE_DATA |
595 I2C_FUNC_SMBUS_WRITE_WORD_DATA;
596 struct sx150x_platform_data *pdata;
597 struct sx150x_chip *chip;
600 pdata = client->dev.platform_data;
604 if (!i2c_check_functionality(client->adapter, i2c_funcs))
607 chip = kzalloc(sizeof(struct sx150x_chip), GFP_KERNEL);
611 sx150x_init_chip(chip, client, id->driver_data, pdata);
612 rc = sx150x_init_hw(chip, pdata);
614 goto probe_fail_pre_gpiochip_add;
616 rc = gpiochip_add(&chip->gpio_chip);
618 goto probe_fail_pre_gpiochip_add;
620 if (pdata->irq_summary >= 0) {
621 rc = sx150x_install_irq_chip(chip,
625 goto probe_fail_post_gpiochip_add;
628 i2c_set_clientdata(client, chip);
631 probe_fail_post_gpiochip_add:
632 WARN_ON(gpiochip_remove(&chip->gpio_chip) < 0);
633 probe_fail_pre_gpiochip_add:
638 static int __devexit sx150x_remove(struct i2c_client *client)
640 struct sx150x_chip *chip;
643 chip = i2c_get_clientdata(client);
644 rc = gpiochip_remove(&chip->gpio_chip);
648 if (chip->irq_summary >= 0)
649 sx150x_remove_irq_chip(chip);
656 static struct i2c_driver sx150x_driver = {
661 .probe = sx150x_probe,
662 .remove = __devexit_p(sx150x_remove),
663 .id_table = sx150x_id,
666 static int __init sx150x_init(void)
668 return i2c_add_driver(&sx150x_driver);
670 subsys_initcall(sx150x_init);
672 static void __exit sx150x_exit(void)
674 return i2c_del_driver(&sx150x_driver);
676 module_exit(sx150x_exit);
678 MODULE_AUTHOR("Gregory Bean <gbean@codeaurora.org>");
679 MODULE_DESCRIPTION("Driver for Semtech SX150X I2C GPIO Expanders");
680 MODULE_LICENSE("GPL v2");
681 MODULE_ALIAS("i2c:sx150x");