Root/drivers/gpio/gpio-max732x.c

1/*
2 * MAX732x I2C Port Expander with 8/16 I/O
3 *
4 * Copyright (C) 2007 Marvell International Ltd.
5 * Copyright (C) 2008 Jack Ren <jack.ren@marvell.com>
6 * Copyright (C) 2008 Eric Miao <eric.miao@marvell.com>
7 *
8 * Derived from drivers/gpio/pca953x.c
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; version 2 of the License.
13 */
14
15#include <linux/module.h>
16#include <linux/init.h>
17#include <linux/slab.h>
18#include <linux/string.h>
19#include <linux/gpio.h>
20#include <linux/interrupt.h>
21#include <linux/irq.h>
22#include <linux/i2c.h>
23#include <linux/i2c/max732x.h>
24
25
26/*
27 * Each port of MAX732x (including MAX7319) falls into one of the
28 * following three types:
29 *
30 * - Push Pull Output
31 * - Input
32 * - Open Drain I/O
33 *
34 * designated by 'O', 'I' and 'P' individually according to MAXIM's
35 * datasheets. 'I' and 'P' ports are interrupt capables, some with
36 * a dedicated interrupt mask.
37 *
38 * There are two groups of I/O ports, each group usually includes
39 * up to 8 I/O ports, and is accessed by a specific I2C address:
40 *
41 * - Group A : by I2C address 0b'110xxxx
42 * - Group B : by I2C address 0b'101xxxx
43 *
44 * where 'xxxx' is decided by the connections of pin AD2/AD0. The
45 * address used also affects the initial state of output signals.
46 *
47 * Within each group of ports, there are five known combinations of
48 * I/O ports: 4I4O, 4P4O, 8I, 8P, 8O, see the definitions below for
49 * the detailed organization of these ports. Only Goup A is interrupt
50 * capable.
51 *
52 * GPIO numbers start from 'gpio_base + 0' to 'gpio_base + 8/16',
53 * and GPIOs from GROUP_A are numbered before those from GROUP_B
54 * (if there are two groups).
55 *
56 * NOTE: MAX7328/MAX7329 are drop-in replacements for PCF8574/a, so
57 * they are not supported by this driver.
58 */
59
60#define PORT_NONE 0x0 /* '/' No Port */
61#define PORT_OUTPUT 0x1 /* 'O' Push-Pull, Output Only */
62#define PORT_INPUT 0x2 /* 'I' Input Only */
63#define PORT_OPENDRAIN 0x3 /* 'P' Open-Drain, I/O */
64
65#define IO_4I4O 0x5AA5 /* O7 O6 I5 I4 I3 I2 O1 O0 */
66#define IO_4P4O 0x5FF5 /* O7 O6 P5 P4 P3 P2 O1 O0 */
67#define IO_8I 0xAAAA /* I7 I6 I5 I4 I3 I2 I1 I0 */
68#define IO_8P 0xFFFF /* P7 P6 P5 P4 P3 P2 P1 P0 */
69#define IO_8O 0x5555 /* O7 O6 O5 O4 O3 O2 O1 O0 */
70
71#define GROUP_A(x) ((x) & 0xffff) /* I2C Addr: 0b'110xxxx */
72#define GROUP_B(x) ((x) << 16) /* I2C Addr: 0b'101xxxx */
73
74#define INT_NONE 0x0 /* No interrupt capability */
75#define INT_NO_MASK 0x1 /* Has interrupts, no mask */
76#define INT_INDEP_MASK 0x2 /* Has interrupts, independent mask */
77#define INT_MERGED_MASK 0x3 /* Has interrupts, merged mask */
78
79#define INT_CAPS(x) (((uint64_t)(x)) << 32)
80
81enum {
82    MAX7319,
83    MAX7320,
84    MAX7321,
85    MAX7322,
86    MAX7323,
87    MAX7324,
88    MAX7325,
89    MAX7326,
90    MAX7327,
91};
92
93static uint64_t max732x_features[] = {
94    [MAX7319] = GROUP_A(IO_8I) | INT_CAPS(INT_MERGED_MASK),
95    [MAX7320] = GROUP_B(IO_8O),
96    [MAX7321] = GROUP_A(IO_8P) | INT_CAPS(INT_NO_MASK),
97    [MAX7322] = GROUP_A(IO_4I4O) | INT_CAPS(INT_MERGED_MASK),
98    [MAX7323] = GROUP_A(IO_4P4O) | INT_CAPS(INT_INDEP_MASK),
99    [MAX7324] = GROUP_A(IO_8I) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK),
100    [MAX7325] = GROUP_A(IO_8P) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK),
101    [MAX7326] = GROUP_A(IO_4I4O) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK),
102    [MAX7327] = GROUP_A(IO_4P4O) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK),
103};
104
105static const struct i2c_device_id max732x_id[] = {
106    { "max7319", MAX7319 },
107    { "max7320", MAX7320 },
108    { "max7321", MAX7321 },
109    { "max7322", MAX7322 },
110    { "max7323", MAX7323 },
111    { "max7324", MAX7324 },
112    { "max7325", MAX7325 },
113    { "max7326", MAX7326 },
114    { "max7327", MAX7327 },
115    { },
116};
117MODULE_DEVICE_TABLE(i2c, max732x_id);
118
119struct max732x_chip {
120    struct gpio_chip gpio_chip;
121
122    struct i2c_client *client; /* "main" client */
123    struct i2c_client *client_dummy;
124    struct i2c_client *client_group_a;
125    struct i2c_client *client_group_b;
126
127    unsigned int mask_group_a;
128    unsigned int dir_input;
129    unsigned int dir_output;
130
131    struct mutex lock;
132    uint8_t reg_out[2];
133
134#ifdef CONFIG_GPIO_MAX732X_IRQ
135    struct mutex irq_lock;
136    int irq_base;
137    uint8_t irq_mask;
138    uint8_t irq_mask_cur;
139    uint8_t irq_trig_raise;
140    uint8_t irq_trig_fall;
141    uint8_t irq_features;
142#endif
143};
144
145static int max732x_writeb(struct max732x_chip *chip, int group_a, uint8_t val)
146{
147    struct i2c_client *client;
148    int ret;
149
150    client = group_a ? chip->client_group_a : chip->client_group_b;
151    ret = i2c_smbus_write_byte(client, val);
152    if (ret < 0) {
153        dev_err(&client->dev, "failed writing\n");
154        return ret;
155    }
156
157    return 0;
158}
159
160static int max732x_readb(struct max732x_chip *chip, int group_a, uint8_t *val)
161{
162    struct i2c_client *client;
163    int ret;
164
165    client = group_a ? chip->client_group_a : chip->client_group_b;
166    ret = i2c_smbus_read_byte(client);
167    if (ret < 0) {
168        dev_err(&client->dev, "failed reading\n");
169        return ret;
170    }
171
172    *val = (uint8_t)ret;
173    return 0;
174}
175
176static inline int is_group_a(struct max732x_chip *chip, unsigned off)
177{
178    return (1u << off) & chip->mask_group_a;
179}
180
181static int max732x_gpio_get_value(struct gpio_chip *gc, unsigned off)
182{
183    struct max732x_chip *chip;
184    uint8_t reg_val;
185    int ret;
186
187    chip = container_of(gc, struct max732x_chip, gpio_chip);
188
189    ret = max732x_readb(chip, is_group_a(chip, off), &reg_val);
190    if (ret < 0)
191        return 0;
192
193    return reg_val & (1u << (off & 0x7));
194}
195
196static void max732x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
197{
198    struct max732x_chip *chip;
199    uint8_t reg_out, mask = 1u << (off & 0x7);
200    int ret;
201
202    chip = container_of(gc, struct max732x_chip, gpio_chip);
203
204    mutex_lock(&chip->lock);
205
206    reg_out = (off > 7) ? chip->reg_out[1] : chip->reg_out[0];
207    reg_out = (val) ? reg_out | mask : reg_out & ~mask;
208
209    ret = max732x_writeb(chip, is_group_a(chip, off), reg_out);
210    if (ret < 0)
211        goto out;
212
213    /* update the shadow register then */
214    if (off > 7)
215        chip->reg_out[1] = reg_out;
216    else
217        chip->reg_out[0] = reg_out;
218out:
219    mutex_unlock(&chip->lock);
220}
221
222static int max732x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
223{
224    struct max732x_chip *chip;
225    unsigned int mask = 1u << off;
226
227    chip = container_of(gc, struct max732x_chip, gpio_chip);
228
229    if ((mask & chip->dir_input) == 0) {
230        dev_dbg(&chip->client->dev, "%s port %d is output only\n",
231            chip->client->name, off);
232        return -EACCES;
233    }
234
235    /*
236     * Open-drain pins must be set to high impedance (which is
237     * equivalent to output-high) to be turned into an input.
238     */
239    if ((mask & chip->dir_output))
240        max732x_gpio_set_value(gc, off, 1);
241
242    return 0;
243}
244
245static int max732x_gpio_direction_output(struct gpio_chip *gc,
246        unsigned off, int val)
247{
248    struct max732x_chip *chip;
249    unsigned int mask = 1u << off;
250
251    chip = container_of(gc, struct max732x_chip, gpio_chip);
252
253    if ((mask & chip->dir_output) == 0) {
254        dev_dbg(&chip->client->dev, "%s port %d is input only\n",
255            chip->client->name, off);
256        return -EACCES;
257    }
258
259    max732x_gpio_set_value(gc, off, val);
260    return 0;
261}
262
263#ifdef CONFIG_GPIO_MAX732X_IRQ
264static int max732x_writew(struct max732x_chip *chip, uint16_t val)
265{
266    int ret;
267
268    val = cpu_to_le16(val);
269
270    ret = i2c_master_send(chip->client_group_a, (char *)&val, 2);
271    if (ret < 0) {
272        dev_err(&chip->client_group_a->dev, "failed writing\n");
273        return ret;
274    }
275
276    return 0;
277}
278
279static int max732x_readw(struct max732x_chip *chip, uint16_t *val)
280{
281    int ret;
282
283    ret = i2c_master_recv(chip->client_group_a, (char *)val, 2);
284    if (ret < 0) {
285        dev_err(&chip->client_group_a->dev, "failed reading\n");
286        return ret;
287    }
288
289    *val = le16_to_cpu(*val);
290    return 0;
291}
292
293static void max732x_irq_update_mask(struct max732x_chip *chip)
294{
295    uint16_t msg;
296
297    if (chip->irq_mask == chip->irq_mask_cur)
298        return;
299
300    chip->irq_mask = chip->irq_mask_cur;
301
302    if (chip->irq_features == INT_NO_MASK)
303        return;
304
305    mutex_lock(&chip->lock);
306
307    switch (chip->irq_features) {
308    case INT_INDEP_MASK:
309        msg = (chip->irq_mask << 8) | chip->reg_out[0];
310        max732x_writew(chip, msg);
311        break;
312
313    case INT_MERGED_MASK:
314        msg = chip->irq_mask | chip->reg_out[0];
315        max732x_writeb(chip, 1, (uint8_t)msg);
316        break;
317    }
318
319    mutex_unlock(&chip->lock);
320}
321
322static int max732x_gpio_to_irq(struct gpio_chip *gc, unsigned off)
323{
324    struct max732x_chip *chip;
325
326    chip = container_of(gc, struct max732x_chip, gpio_chip);
327    return chip->irq_base + off;
328}
329
330static void max732x_irq_mask(struct irq_data *d)
331{
332    struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
333
334    chip->irq_mask_cur &= ~(1 << (d->irq - chip->irq_base));
335}
336
337static void max732x_irq_unmask(struct irq_data *d)
338{
339    struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
340
341    chip->irq_mask_cur |= 1 << (d->irq - chip->irq_base);
342}
343
344static void max732x_irq_bus_lock(struct irq_data *d)
345{
346    struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
347
348    mutex_lock(&chip->irq_lock);
349    chip->irq_mask_cur = chip->irq_mask;
350}
351
352static void max732x_irq_bus_sync_unlock(struct irq_data *d)
353{
354    struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
355
356    max732x_irq_update_mask(chip);
357    mutex_unlock(&chip->irq_lock);
358}
359
360static int max732x_irq_set_type(struct irq_data *d, unsigned int type)
361{
362    struct max732x_chip *chip = irq_data_get_irq_chip_data(d);
363    uint16_t off = d->irq - chip->irq_base;
364    uint16_t mask = 1 << off;
365
366    if (!(mask & chip->dir_input)) {
367        dev_dbg(&chip->client->dev, "%s port %d is output only\n",
368            chip->client->name, off);
369        return -EACCES;
370    }
371
372    if (!(type & IRQ_TYPE_EDGE_BOTH)) {
373        dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
374            d->irq, type);
375        return -EINVAL;
376    }
377
378    if (type & IRQ_TYPE_EDGE_FALLING)
379        chip->irq_trig_fall |= mask;
380    else
381        chip->irq_trig_fall &= ~mask;
382
383    if (type & IRQ_TYPE_EDGE_RISING)
384        chip->irq_trig_raise |= mask;
385    else
386        chip->irq_trig_raise &= ~mask;
387
388    return max732x_gpio_direction_input(&chip->gpio_chip, off);
389}
390
391static struct irq_chip max732x_irq_chip = {
392    .name = "max732x",
393    .irq_mask = max732x_irq_mask,
394    .irq_unmask = max732x_irq_unmask,
395    .irq_bus_lock = max732x_irq_bus_lock,
396    .irq_bus_sync_unlock = max732x_irq_bus_sync_unlock,
397    .irq_set_type = max732x_irq_set_type,
398};
399
400static uint8_t max732x_irq_pending(struct max732x_chip *chip)
401{
402    uint8_t cur_stat;
403    uint8_t old_stat;
404    uint8_t trigger;
405    uint8_t pending;
406    uint16_t status;
407    int ret;
408
409    ret = max732x_readw(chip, &status);
410    if (ret)
411        return 0;
412
413    trigger = status >> 8;
414    trigger &= chip->irq_mask;
415
416    if (!trigger)
417        return 0;
418
419    cur_stat = status & 0xFF;
420    cur_stat &= chip->irq_mask;
421
422    old_stat = cur_stat ^ trigger;
423
424    pending = (old_stat & chip->irq_trig_fall) |
425          (cur_stat & chip->irq_trig_raise);
426    pending &= trigger;
427
428    return pending;
429}
430
431static irqreturn_t max732x_irq_handler(int irq, void *devid)
432{
433    struct max732x_chip *chip = devid;
434    uint8_t pending;
435    uint8_t level;
436
437    pending = max732x_irq_pending(chip);
438
439    if (!pending)
440        return IRQ_HANDLED;
441
442    do {
443        level = __ffs(pending);
444        handle_nested_irq(level + chip->irq_base);
445
446        pending &= ~(1 << level);
447    } while (pending);
448
449    return IRQ_HANDLED;
450}
451
452static int max732x_irq_setup(struct max732x_chip *chip,
453                 const struct i2c_device_id *id)
454{
455    struct i2c_client *client = chip->client;
456    struct max732x_platform_data *pdata = client->dev.platform_data;
457    int has_irq = max732x_features[id->driver_data] >> 32;
458    int ret;
459
460    if (pdata->irq_base && has_irq != INT_NONE) {
461        int lvl;
462
463        chip->irq_base = pdata->irq_base;
464        chip->irq_features = has_irq;
465        mutex_init(&chip->irq_lock);
466
467        for (lvl = 0; lvl < chip->gpio_chip.ngpio; lvl++) {
468            int irq = lvl + chip->irq_base;
469
470            if (!(chip->dir_input & (1 << lvl)))
471                continue;
472
473            irq_set_chip_data(irq, chip);
474            irq_set_chip_and_handler(irq, &max732x_irq_chip,
475                         handle_edge_irq);
476            irq_set_nested_thread(irq, 1);
477#ifdef CONFIG_ARM
478            set_irq_flags(irq, IRQF_VALID);
479#else
480            irq_set_noprobe(irq);
481#endif
482        }
483
484        ret = request_threaded_irq(client->irq,
485                       NULL,
486                       max732x_irq_handler,
487                       IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
488                       dev_name(&client->dev), chip);
489        if (ret) {
490            dev_err(&client->dev, "failed to request irq %d\n",
491                client->irq);
492            goto out_failed;
493        }
494
495        chip->gpio_chip.to_irq = max732x_gpio_to_irq;
496    }
497
498    return 0;
499
500out_failed:
501    chip->irq_base = 0;
502    return ret;
503}
504
505static void max732x_irq_teardown(struct max732x_chip *chip)
506{
507    if (chip->irq_base)
508        free_irq(chip->client->irq, chip);
509}
510#else /* CONFIG_GPIO_MAX732X_IRQ */
511static int max732x_irq_setup(struct max732x_chip *chip,
512                 const struct i2c_device_id *id)
513{
514    struct i2c_client *client = chip->client;
515    struct max732x_platform_data *pdata = client->dev.platform_data;
516    int has_irq = max732x_features[id->driver_data] >> 32;
517
518    if (pdata->irq_base && has_irq != INT_NONE)
519        dev_warn(&client->dev, "interrupt support not compiled in\n");
520
521    return 0;
522}
523
524static void max732x_irq_teardown(struct max732x_chip *chip)
525{
526}
527#endif
528
529static int __devinit max732x_setup_gpio(struct max732x_chip *chip,
530                    const struct i2c_device_id *id,
531                    unsigned gpio_start)
532{
533    struct gpio_chip *gc = &chip->gpio_chip;
534    uint32_t id_data = (uint32_t)max732x_features[id->driver_data];
535    int i, port = 0;
536
537    for (i = 0; i < 16; i++, id_data >>= 2) {
538        unsigned int mask = 1 << port;
539
540        switch (id_data & 0x3) {
541        case PORT_OUTPUT:
542            chip->dir_output |= mask;
543            break;
544        case PORT_INPUT:
545            chip->dir_input |= mask;
546            break;
547        case PORT_OPENDRAIN:
548            chip->dir_output |= mask;
549            chip->dir_input |= mask;
550            break;
551        default:
552            continue;
553        }
554
555        if (i < 8)
556            chip->mask_group_a |= mask;
557        port++;
558    }
559
560    if (chip->dir_input)
561        gc->direction_input = max732x_gpio_direction_input;
562    if (chip->dir_output) {
563        gc->direction_output = max732x_gpio_direction_output;
564        gc->set = max732x_gpio_set_value;
565    }
566    gc->get = max732x_gpio_get_value;
567    gc->can_sleep = 1;
568
569    gc->base = gpio_start;
570    gc->ngpio = port;
571    gc->label = chip->client->name;
572    gc->owner = THIS_MODULE;
573
574    return port;
575}
576
577static int __devinit max732x_probe(struct i2c_client *client,
578                   const struct i2c_device_id *id)
579{
580    struct max732x_platform_data *pdata;
581    struct max732x_chip *chip;
582    struct i2c_client *c;
583    uint16_t addr_a, addr_b;
584    int ret, nr_port;
585
586    pdata = client->dev.platform_data;
587    if (pdata == NULL) {
588        dev_dbg(&client->dev, "no platform data\n");
589        return -EINVAL;
590    }
591
592    chip = kzalloc(sizeof(struct max732x_chip), GFP_KERNEL);
593    if (chip == NULL)
594        return -ENOMEM;
595    chip->client = client;
596
597    nr_port = max732x_setup_gpio(chip, id, pdata->gpio_base);
598
599    addr_a = (client->addr & 0x0f) | 0x60;
600    addr_b = (client->addr & 0x0f) | 0x50;
601
602    switch (client->addr & 0x70) {
603    case 0x60:
604        chip->client_group_a = client;
605        if (nr_port > 8) {
606            c = i2c_new_dummy(client->adapter, addr_b);
607            chip->client_group_b = chip->client_dummy = c;
608        }
609        break;
610    case 0x50:
611        chip->client_group_b = client;
612        if (nr_port > 8) {
613            c = i2c_new_dummy(client->adapter, addr_a);
614            chip->client_group_a = chip->client_dummy = c;
615        }
616        break;
617    default:
618        dev_err(&client->dev, "invalid I2C address specified %02x\n",
619                client->addr);
620        ret = -EINVAL;
621        goto out_failed;
622    }
623
624    mutex_init(&chip->lock);
625
626    max732x_readb(chip, is_group_a(chip, 0), &chip->reg_out[0]);
627    if (nr_port > 8)
628        max732x_readb(chip, is_group_a(chip, 8), &chip->reg_out[1]);
629
630    ret = max732x_irq_setup(chip, id);
631    if (ret)
632        goto out_failed;
633
634    ret = gpiochip_add(&chip->gpio_chip);
635    if (ret)
636        goto out_failed;
637
638    if (pdata->setup) {
639        ret = pdata->setup(client, chip->gpio_chip.base,
640                chip->gpio_chip.ngpio, pdata->context);
641        if (ret < 0)
642            dev_warn(&client->dev, "setup failed, %d\n", ret);
643    }
644
645    i2c_set_clientdata(client, chip);
646    return 0;
647
648out_failed:
649    max732x_irq_teardown(chip);
650    kfree(chip);
651    return ret;
652}
653
654static int __devexit max732x_remove(struct i2c_client *client)
655{
656    struct max732x_platform_data *pdata = client->dev.platform_data;
657    struct max732x_chip *chip = i2c_get_clientdata(client);
658    int ret;
659
660    if (pdata->teardown) {
661        ret = pdata->teardown(client, chip->gpio_chip.base,
662                chip->gpio_chip.ngpio, pdata->context);
663        if (ret < 0) {
664            dev_err(&client->dev, "%s failed, %d\n",
665                    "teardown", ret);
666            return ret;
667        }
668    }
669
670    ret = gpiochip_remove(&chip->gpio_chip);
671    if (ret) {
672        dev_err(&client->dev, "%s failed, %d\n",
673                "gpiochip_remove()", ret);
674        return ret;
675    }
676
677    max732x_irq_teardown(chip);
678
679    /* unregister any dummy i2c_client */
680    if (chip->client_dummy)
681        i2c_unregister_device(chip->client_dummy);
682
683    kfree(chip);
684    return 0;
685}
686
687static struct i2c_driver max732x_driver = {
688    .driver = {
689        .name = "max732x",
690        .owner = THIS_MODULE,
691    },
692    .probe = max732x_probe,
693    .remove = __devexit_p(max732x_remove),
694    .id_table = max732x_id,
695};
696
697static int __init max732x_init(void)
698{
699    return i2c_add_driver(&max732x_driver);
700}
701/* register after i2c postcore initcall and before
702 * subsys initcalls that may rely on these GPIOs
703 */
704subsys_initcall(max732x_init);
705
706static void __exit max732x_exit(void)
707{
708    i2c_del_driver(&max732x_driver);
709}
710module_exit(max732x_exit);
711
712MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
713MODULE_DESCRIPTION("GPIO expander driver for MAX732X");
714MODULE_LICENSE("GPL");
715

Archive Download this file

Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master

Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9



interactive