Root/drivers/gpio/gpio-mcp23s08.c

1/*
2 * MCP23S08 SPI/GPIO gpio expander driver
3 */
4
5#include <linux/kernel.h>
6#include <linux/device.h>
7#include <linux/mutex.h>
8#include <linux/module.h>
9#include <linux/gpio.h>
10#include <linux/i2c.h>
11#include <linux/spi/spi.h>
12#include <linux/spi/mcp23s08.h>
13#include <linux/slab.h>
14#include <asm/byteorder.h>
15
16/**
17 * MCP types supported by driver
18 */
19#define MCP_TYPE_S08 0
20#define MCP_TYPE_S17 1
21#define MCP_TYPE_008 2
22#define MCP_TYPE_017 3
23
24/* Registers are all 8 bits wide.
25 *
26 * The mcp23s17 has twice as many bits, and can be configured to work
27 * with either 16 bit registers or with two adjacent 8 bit banks.
28 */
29#define MCP_IODIR 0x00 /* init/reset: all ones */
30#define MCP_IPOL 0x01
31#define MCP_GPINTEN 0x02
32#define MCP_DEFVAL 0x03
33#define MCP_INTCON 0x04
34#define MCP_IOCON 0x05
35# define IOCON_SEQOP (1 << 5)
36# define IOCON_HAEN (1 << 3)
37# define IOCON_ODR (1 << 2)
38# define IOCON_INTPOL (1 << 1)
39#define MCP_GPPU 0x06
40#define MCP_INTF 0x07
41#define MCP_INTCAP 0x08
42#define MCP_GPIO 0x09
43#define MCP_OLAT 0x0a
44
45struct mcp23s08;
46
47struct mcp23s08_ops {
48    int (*read)(struct mcp23s08 *mcp, unsigned reg);
49    int (*write)(struct mcp23s08 *mcp, unsigned reg, unsigned val);
50    int (*read_regs)(struct mcp23s08 *mcp, unsigned reg,
51                 u16 *vals, unsigned n);
52};
53
54struct mcp23s08 {
55    u8 addr;
56
57    u16 cache[11];
58    /* lock protects the cached values */
59    struct mutex lock;
60
61    struct gpio_chip chip;
62
63    const struct mcp23s08_ops *ops;
64    void *data; /* ops specific data */
65};
66
67/* A given spi_device can represent up to eight mcp23sxx chips
68 * sharing the same chipselect but using different addresses
69 * (e.g. chips #0 and #3 might be populated, but not #1 or $2).
70 * Driver data holds all the per-chip data.
71 */
72struct mcp23s08_driver_data {
73    unsigned ngpio;
74    struct mcp23s08 *mcp[8];
75    struct mcp23s08 chip[];
76};
77
78/*----------------------------------------------------------------------*/
79
80#ifdef CONFIG_I2C
81
82static int mcp23008_read(struct mcp23s08 *mcp, unsigned reg)
83{
84    return i2c_smbus_read_byte_data(mcp->data, reg);
85}
86
87static int mcp23008_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
88{
89    return i2c_smbus_write_byte_data(mcp->data, reg, val);
90}
91
92static int
93mcp23008_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
94{
95    while (n--) {
96        int ret = mcp23008_read(mcp, reg++);
97        if (ret < 0)
98            return ret;
99        *vals++ = ret;
100    }
101
102    return 0;
103}
104
105static int mcp23017_read(struct mcp23s08 *mcp, unsigned reg)
106{
107    return i2c_smbus_read_word_data(mcp->data, reg << 1);
108}
109
110static int mcp23017_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
111{
112    return i2c_smbus_write_word_data(mcp->data, reg << 1, val);
113}
114
115static int
116mcp23017_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
117{
118    while (n--) {
119        int ret = mcp23017_read(mcp, reg++);
120        if (ret < 0)
121            return ret;
122        *vals++ = ret;
123    }
124
125    return 0;
126}
127
128static const struct mcp23s08_ops mcp23008_ops = {
129    .read = mcp23008_read,
130    .write = mcp23008_write,
131    .read_regs = mcp23008_read_regs,
132};
133
134static const struct mcp23s08_ops mcp23017_ops = {
135    .read = mcp23017_read,
136    .write = mcp23017_write,
137    .read_regs = mcp23017_read_regs,
138};
139
140#endif /* CONFIG_I2C */
141
142/*----------------------------------------------------------------------*/
143
144#ifdef CONFIG_SPI_MASTER
145
146static int mcp23s08_read(struct mcp23s08 *mcp, unsigned reg)
147{
148    u8 tx[2], rx[1];
149    int status;
150
151    tx[0] = mcp->addr | 0x01;
152    tx[1] = reg;
153    status = spi_write_then_read(mcp->data, tx, sizeof tx, rx, sizeof rx);
154    return (status < 0) ? status : rx[0];
155}
156
157static int mcp23s08_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
158{
159    u8 tx[3];
160
161    tx[0] = mcp->addr;
162    tx[1] = reg;
163    tx[2] = val;
164    return spi_write_then_read(mcp->data, tx, sizeof tx, NULL, 0);
165}
166
167static int
168mcp23s08_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
169{
170    u8 tx[2], *tmp;
171    int status;
172
173    if ((n + reg) > sizeof mcp->cache)
174        return -EINVAL;
175    tx[0] = mcp->addr | 0x01;
176    tx[1] = reg;
177
178    tmp = (u8 *)vals;
179    status = spi_write_then_read(mcp->data, tx, sizeof tx, tmp, n);
180    if (status >= 0) {
181        while (n--)
182            vals[n] = tmp[n]; /* expand to 16bit */
183    }
184    return status;
185}
186
187static int mcp23s17_read(struct mcp23s08 *mcp, unsigned reg)
188{
189    u8 tx[2], rx[2];
190    int status;
191
192    tx[0] = mcp->addr | 0x01;
193    tx[1] = reg << 1;
194    status = spi_write_then_read(mcp->data, tx, sizeof tx, rx, sizeof rx);
195    return (status < 0) ? status : (rx[0] | (rx[1] << 8));
196}
197
198static int mcp23s17_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
199{
200    u8 tx[4];
201
202    tx[0] = mcp->addr;
203    tx[1] = reg << 1;
204    tx[2] = val;
205    tx[3] = val >> 8;
206    return spi_write_then_read(mcp->data, tx, sizeof tx, NULL, 0);
207}
208
209static int
210mcp23s17_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
211{
212    u8 tx[2];
213    int status;
214
215    if ((n + reg) > sizeof mcp->cache)
216        return -EINVAL;
217    tx[0] = mcp->addr | 0x01;
218    tx[1] = reg << 1;
219
220    status = spi_write_then_read(mcp->data, tx, sizeof tx,
221                     (u8 *)vals, n * 2);
222    if (status >= 0) {
223        while (n--)
224            vals[n] = __le16_to_cpu((__le16)vals[n]);
225    }
226
227    return status;
228}
229
230static const struct mcp23s08_ops mcp23s08_ops = {
231    .read = mcp23s08_read,
232    .write = mcp23s08_write,
233    .read_regs = mcp23s08_read_regs,
234};
235
236static const struct mcp23s08_ops mcp23s17_ops = {
237    .read = mcp23s17_read,
238    .write = mcp23s17_write,
239    .read_regs = mcp23s17_read_regs,
240};
241
242#endif /* CONFIG_SPI_MASTER */
243
244/*----------------------------------------------------------------------*/
245
246static int mcp23s08_direction_input(struct gpio_chip *chip, unsigned offset)
247{
248    struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
249    int status;
250
251    mutex_lock(&mcp->lock);
252    mcp->cache[MCP_IODIR] |= (1 << offset);
253    status = mcp->ops->write(mcp, MCP_IODIR, mcp->cache[MCP_IODIR]);
254    mutex_unlock(&mcp->lock);
255    return status;
256}
257
258static int mcp23s08_get(struct gpio_chip *chip, unsigned offset)
259{
260    struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
261    int status;
262
263    mutex_lock(&mcp->lock);
264
265    /* REVISIT reading this clears any IRQ ... */
266    status = mcp->ops->read(mcp, MCP_GPIO);
267    if (status < 0)
268        status = 0;
269    else {
270        mcp->cache[MCP_GPIO] = status;
271        status = !!(status & (1 << offset));
272    }
273    mutex_unlock(&mcp->lock);
274    return status;
275}
276
277static int __mcp23s08_set(struct mcp23s08 *mcp, unsigned mask, int value)
278{
279    unsigned olat = mcp->cache[MCP_OLAT];
280
281    if (value)
282        olat |= mask;
283    else
284        olat &= ~mask;
285    mcp->cache[MCP_OLAT] = olat;
286    return mcp->ops->write(mcp, MCP_OLAT, olat);
287}
288
289static void mcp23s08_set(struct gpio_chip *chip, unsigned offset, int value)
290{
291    struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
292    unsigned mask = 1 << offset;
293
294    mutex_lock(&mcp->lock);
295    __mcp23s08_set(mcp, mask, value);
296    mutex_unlock(&mcp->lock);
297}
298
299static int
300mcp23s08_direction_output(struct gpio_chip *chip, unsigned offset, int value)
301{
302    struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
303    unsigned mask = 1 << offset;
304    int status;
305
306    mutex_lock(&mcp->lock);
307    status = __mcp23s08_set(mcp, mask, value);
308    if (status == 0) {
309        mcp->cache[MCP_IODIR] &= ~mask;
310        status = mcp->ops->write(mcp, MCP_IODIR, mcp->cache[MCP_IODIR]);
311    }
312    mutex_unlock(&mcp->lock);
313    return status;
314}
315
316/*----------------------------------------------------------------------*/
317
318#ifdef CONFIG_DEBUG_FS
319
320#include <linux/seq_file.h>
321
322/*
323 * This shows more info than the generic gpio dump code:
324 * pullups, deglitching, open drain drive.
325 */
326static void mcp23s08_dbg_show(struct seq_file *s, struct gpio_chip *chip)
327{
328    struct mcp23s08 *mcp;
329    char bank;
330    int t;
331    unsigned mask;
332
333    mcp = container_of(chip, struct mcp23s08, chip);
334
335    /* NOTE: we only handle one bank for now ... */
336    bank = '0' + ((mcp->addr >> 1) & 0x7);
337
338    mutex_lock(&mcp->lock);
339    t = mcp->ops->read_regs(mcp, 0, mcp->cache, ARRAY_SIZE(mcp->cache));
340    if (t < 0) {
341        seq_printf(s, " I/O ERROR %d\n", t);
342        goto done;
343    }
344
345    for (t = 0, mask = 1; t < chip->ngpio; t++, mask <<= 1) {
346        const char *label;
347
348        label = gpiochip_is_requested(chip, t);
349        if (!label)
350            continue;
351
352        seq_printf(s, " gpio-%-3d P%c.%d (%-12s) %s %s %s",
353            chip->base + t, bank, t, label,
354            (mcp->cache[MCP_IODIR] & mask) ? "in " : "out",
355            (mcp->cache[MCP_GPIO] & mask) ? "hi" : "lo",
356            (mcp->cache[MCP_GPPU] & mask) ? "up" : " ");
357        /* NOTE: ignoring the irq-related registers */
358        seq_printf(s, "\n");
359    }
360done:
361    mutex_unlock(&mcp->lock);
362}
363
364#else
365#define mcp23s08_dbg_show NULL
366#endif
367
368/*----------------------------------------------------------------------*/
369
370static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
371                  void *data, unsigned addr,
372                  unsigned type, unsigned base, unsigned pullups)
373{
374    int status;
375
376    mutex_init(&mcp->lock);
377
378    mcp->data = data;
379    mcp->addr = addr;
380
381    mcp->chip.direction_input = mcp23s08_direction_input;
382    mcp->chip.get = mcp23s08_get;
383    mcp->chip.direction_output = mcp23s08_direction_output;
384    mcp->chip.set = mcp23s08_set;
385    mcp->chip.dbg_show = mcp23s08_dbg_show;
386
387    switch (type) {
388#ifdef CONFIG_SPI_MASTER
389    case MCP_TYPE_S08:
390        mcp->ops = &mcp23s08_ops;
391        mcp->chip.ngpio = 8;
392        mcp->chip.label = "mcp23s08";
393        break;
394
395    case MCP_TYPE_S17:
396        mcp->ops = &mcp23s17_ops;
397        mcp->chip.ngpio = 16;
398        mcp->chip.label = "mcp23s17";
399        break;
400#endif /* CONFIG_SPI_MASTER */
401
402#ifdef CONFIG_I2C
403    case MCP_TYPE_008:
404        mcp->ops = &mcp23008_ops;
405        mcp->chip.ngpio = 8;
406        mcp->chip.label = "mcp23008";
407        break;
408
409    case MCP_TYPE_017:
410        mcp->ops = &mcp23017_ops;
411        mcp->chip.ngpio = 16;
412        mcp->chip.label = "mcp23017";
413        break;
414#endif /* CONFIG_I2C */
415
416    default:
417        dev_err(dev, "invalid device type (%d)\n", type);
418        return -EINVAL;
419    }
420
421    mcp->chip.base = base;
422    mcp->chip.can_sleep = 1;
423    mcp->chip.dev = dev;
424    mcp->chip.owner = THIS_MODULE;
425
426    /* verify MCP_IOCON.SEQOP = 0, so sequential reads work,
427     * and MCP_IOCON.HAEN = 1, so we work with all chips.
428     */
429    status = mcp->ops->read(mcp, MCP_IOCON);
430    if (status < 0)
431        goto fail;
432    if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN)) {
433        /* mcp23s17 has IOCON twice, make sure they are in sync */
434        status &= ~(IOCON_SEQOP | (IOCON_SEQOP << 8));
435        status |= IOCON_HAEN | (IOCON_HAEN << 8);
436        status = mcp->ops->write(mcp, MCP_IOCON, status);
437        if (status < 0)
438            goto fail;
439    }
440
441    /* configure ~100K pullups */
442    status = mcp->ops->write(mcp, MCP_GPPU, pullups);
443    if (status < 0)
444        goto fail;
445
446    status = mcp->ops->read_regs(mcp, 0, mcp->cache, ARRAY_SIZE(mcp->cache));
447    if (status < 0)
448        goto fail;
449
450    /* disable inverter on input */
451    if (mcp->cache[MCP_IPOL] != 0) {
452        mcp->cache[MCP_IPOL] = 0;
453        status = mcp->ops->write(mcp, MCP_IPOL, 0);
454        if (status < 0)
455            goto fail;
456    }
457
458    /* disable irqs */
459    if (mcp->cache[MCP_GPINTEN] != 0) {
460        mcp->cache[MCP_GPINTEN] = 0;
461        status = mcp->ops->write(mcp, MCP_GPINTEN, 0);
462        if (status < 0)
463            goto fail;
464    }
465
466    status = gpiochip_add(&mcp->chip);
467fail:
468    if (status < 0)
469        dev_dbg(dev, "can't setup chip %d, --> %d\n",
470            addr, status);
471    return status;
472}
473
474/*----------------------------------------------------------------------*/
475
476#ifdef CONFIG_I2C
477
478static int __devinit mcp230xx_probe(struct i2c_client *client,
479                    const struct i2c_device_id *id)
480{
481    struct mcp23s08_platform_data *pdata;
482    struct mcp23s08 *mcp;
483    int status;
484
485    pdata = client->dev.platform_data;
486    if (!pdata || !gpio_is_valid(pdata->base)) {
487        dev_dbg(&client->dev, "invalid or missing platform data\n");
488        return -EINVAL;
489    }
490
491    mcp = kzalloc(sizeof *mcp, GFP_KERNEL);
492    if (!mcp)
493        return -ENOMEM;
494
495    status = mcp23s08_probe_one(mcp, &client->dev, client, client->addr,
496                    id->driver_data, pdata->base,
497                    pdata->chip[0].pullups);
498    if (status)
499        goto fail;
500
501    i2c_set_clientdata(client, mcp);
502
503    return 0;
504
505fail:
506    kfree(mcp);
507
508    return status;
509}
510
511static int __devexit mcp230xx_remove(struct i2c_client *client)
512{
513    struct mcp23s08 *mcp = i2c_get_clientdata(client);
514    int status;
515
516    status = gpiochip_remove(&mcp->chip);
517    if (status == 0)
518        kfree(mcp);
519
520    return status;
521}
522
523static const struct i2c_device_id mcp230xx_id[] = {
524    { "mcp23008", MCP_TYPE_008 },
525    { "mcp23017", MCP_TYPE_017 },
526    { },
527};
528MODULE_DEVICE_TABLE(i2c, mcp230xx_id);
529
530static struct i2c_driver mcp230xx_driver = {
531    .driver = {
532        .name = "mcp230xx",
533        .owner = THIS_MODULE,
534    },
535    .probe = mcp230xx_probe,
536    .remove = __devexit_p(mcp230xx_remove),
537    .id_table = mcp230xx_id,
538};
539
540static int __init mcp23s08_i2c_init(void)
541{
542    return i2c_add_driver(&mcp230xx_driver);
543}
544
545static void mcp23s08_i2c_exit(void)
546{
547    i2c_del_driver(&mcp230xx_driver);
548}
549
550#else
551
552static int __init mcp23s08_i2c_init(void) { return 0; }
553static void mcp23s08_i2c_exit(void) { }
554
555#endif /* CONFIG_I2C */
556
557/*----------------------------------------------------------------------*/
558
559#ifdef CONFIG_SPI_MASTER
560
561static int mcp23s08_probe(struct spi_device *spi)
562{
563    struct mcp23s08_platform_data *pdata;
564    unsigned addr;
565    unsigned chips = 0;
566    struct mcp23s08_driver_data *data;
567    int status, type;
568    unsigned base;
569
570    type = spi_get_device_id(spi)->driver_data;
571
572    pdata = spi->dev.platform_data;
573    if (!pdata || !gpio_is_valid(pdata->base)) {
574        dev_dbg(&spi->dev, "invalid or missing platform data\n");
575        return -EINVAL;
576    }
577
578    for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
579        if (!pdata->chip[addr].is_present)
580            continue;
581        chips++;
582        if ((type == MCP_TYPE_S08) && (addr > 3)) {
583            dev_err(&spi->dev,
584                "mcp23s08 only supports address 0..3\n");
585            return -EINVAL;
586        }
587    }
588    if (!chips)
589        return -ENODEV;
590
591    data = kzalloc(sizeof *data + chips * sizeof(struct mcp23s08),
592            GFP_KERNEL);
593    if (!data)
594        return -ENOMEM;
595    spi_set_drvdata(spi, data);
596
597    base = pdata->base;
598    for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
599        if (!pdata->chip[addr].is_present)
600            continue;
601        chips--;
602        data->mcp[addr] = &data->chip[chips];
603        status = mcp23s08_probe_one(data->mcp[addr], &spi->dev, spi,
604                        0x40 | (addr << 1), type, base,
605                        pdata->chip[addr].pullups);
606        if (status < 0)
607            goto fail;
608
609        base += (type == MCP_TYPE_S17) ? 16 : 8;
610    }
611    data->ngpio = base - pdata->base;
612
613    /* NOTE: these chips have a relatively sane IRQ framework, with
614     * per-signal masking and level/edge triggering. It's not yet
615     * handled here...
616     */
617
618    return 0;
619
620fail:
621    for (addr = 0; addr < ARRAY_SIZE(data->mcp); addr++) {
622        int tmp;
623
624        if (!data->mcp[addr])
625            continue;
626        tmp = gpiochip_remove(&data->mcp[addr]->chip);
627        if (tmp < 0)
628            dev_err(&spi->dev, "%s --> %d\n", "remove", tmp);
629    }
630    kfree(data);
631    return status;
632}
633
634static int mcp23s08_remove(struct spi_device *spi)
635{
636    struct mcp23s08_driver_data *data = spi_get_drvdata(spi);
637    unsigned addr;
638    int status = 0;
639
640    for (addr = 0; addr < ARRAY_SIZE(data->mcp); addr++) {
641        int tmp;
642
643        if (!data->mcp[addr])
644            continue;
645
646        tmp = gpiochip_remove(&data->mcp[addr]->chip);
647        if (tmp < 0) {
648            dev_err(&spi->dev, "%s --> %d\n", "remove", tmp);
649            status = tmp;
650        }
651    }
652    if (status == 0)
653        kfree(data);
654    return status;
655}
656
657static const struct spi_device_id mcp23s08_ids[] = {
658    { "mcp23s08", MCP_TYPE_S08 },
659    { "mcp23s17", MCP_TYPE_S17 },
660    { },
661};
662MODULE_DEVICE_TABLE(spi, mcp23s08_ids);
663
664static struct spi_driver mcp23s08_driver = {
665    .probe = mcp23s08_probe,
666    .remove = mcp23s08_remove,
667    .id_table = mcp23s08_ids,
668    .driver = {
669        .name = "mcp23s08",
670        .owner = THIS_MODULE,
671    },
672};
673
674static int __init mcp23s08_spi_init(void)
675{
676    return spi_register_driver(&mcp23s08_driver);
677}
678
679static void mcp23s08_spi_exit(void)
680{
681    spi_unregister_driver(&mcp23s08_driver);
682}
683
684#else
685
686static int __init mcp23s08_spi_init(void) { return 0; }
687static void mcp23s08_spi_exit(void) { }
688
689#endif /* CONFIG_SPI_MASTER */
690
691/*----------------------------------------------------------------------*/
692
693static int __init mcp23s08_init(void)
694{
695    int ret;
696
697    ret = mcp23s08_spi_init();
698    if (ret)
699        goto spi_fail;
700
701    ret = mcp23s08_i2c_init();
702    if (ret)
703        goto i2c_fail;
704
705    return 0;
706
707 i2c_fail:
708    mcp23s08_spi_exit();
709 spi_fail:
710    return ret;
711}
712/* register after spi/i2c postcore initcall and before
713 * subsys initcalls that may rely on these GPIOs
714 */
715subsys_initcall(mcp23s08_init);
716
717static void __exit mcp23s08_exit(void)
718{
719    mcp23s08_spi_exit();
720    mcp23s08_i2c_exit();
721}
722module_exit(mcp23s08_exit);
723
724MODULE_LICENSE("GPL");
725

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