2 * MCP23S08 SPI/GPIO gpio expander driver
5 #include <linux/kernel.h>
6 #include <linux/device.h>
7 #include <linux/mutex.h>
8 #include <linux/gpio.h>
10 #include <linux/spi/spi.h>
11 #include <linux/spi/mcp23s08.h>
12 #include <linux/slab.h>
13 #include <asm/byteorder.h>
16 * MCP types supported by driver
18 #define MCP_TYPE_S08 0
19 #define MCP_TYPE_S17 1
20 #define MCP_TYPE_008 2
21 #define MCP_TYPE_017 3
23 /* Registers are all 8 bits wide.
25 * The mcp23s17 has twice as many bits, and can be configured to work
26 * with either 16 bit registers or with two adjacent 8 bit banks.
28 #define MCP_IODIR 0x00 /* init/reset: all ones */
30 #define MCP_GPINTEN 0x02
31 #define MCP_DEFVAL 0x03
32 #define MCP_INTCON 0x04
33 #define MCP_IOCON 0x05
34 # define IOCON_SEQOP (1 << 5)
35 # define IOCON_HAEN (1 << 3)
36 # define IOCON_ODR (1 << 2)
37 # define IOCON_INTPOL (1 << 1)
40 #define MCP_INTCAP 0x08
47 int (*read)(struct mcp23s08 *mcp, unsigned reg);
48 int (*write)(struct mcp23s08 *mcp, unsigned reg, unsigned val);
49 int (*read_regs)(struct mcp23s08 *mcp, unsigned reg,
50 u16 *vals, unsigned n);
57 /* lock protects the cached values */
60 struct gpio_chip chip;
62 const struct mcp23s08_ops *ops;
63 void *data; /* ops specific data */
66 /* A given spi_device can represent up to eight mcp23sxx chips
67 * sharing the same chipselect but using different addresses
68 * (e.g. chips #0 and #3 might be populated, but not #1 or $2).
69 * Driver data holds all the per-chip data.
71 struct mcp23s08_driver_data {
73 struct mcp23s08 *mcp[8];
74 struct mcp23s08 chip[];
77 /*----------------------------------------------------------------------*/
81 static int mcp23008_read(struct mcp23s08 *mcp, unsigned reg)
83 return i2c_smbus_read_byte_data(mcp->data, reg);
86 static int mcp23008_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
88 return i2c_smbus_write_byte_data(mcp->data, reg, val);
92 mcp23008_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
95 int ret = mcp23008_read(mcp, reg++);
104 static int mcp23017_read(struct mcp23s08 *mcp, unsigned reg)
106 return i2c_smbus_read_word_data(mcp->data, reg << 1);
109 static int mcp23017_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
111 return i2c_smbus_write_word_data(mcp->data, reg << 1, val);
115 mcp23017_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
118 int ret = mcp23017_read(mcp, reg++);
127 static const struct mcp23s08_ops mcp23008_ops = {
128 .read = mcp23008_read,
129 .write = mcp23008_write,
130 .read_regs = mcp23008_read_regs,
133 static const struct mcp23s08_ops mcp23017_ops = {
134 .read = mcp23017_read,
135 .write = mcp23017_write,
136 .read_regs = mcp23017_read_regs,
139 #endif /* CONFIG_I2C */
141 /*----------------------------------------------------------------------*/
143 #ifdef CONFIG_SPI_MASTER
145 static int mcp23s08_read(struct mcp23s08 *mcp, unsigned reg)
150 tx[0] = mcp->addr | 0x01;
152 status = spi_write_then_read(mcp->data, tx, sizeof tx, rx, sizeof rx);
153 return (status < 0) ? status : rx[0];
156 static int mcp23s08_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
163 return spi_write_then_read(mcp->data, tx, sizeof tx, NULL, 0);
167 mcp23s08_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
172 if ((n + reg) > sizeof mcp->cache)
174 tx[0] = mcp->addr | 0x01;
178 status = spi_write_then_read(mcp->data, tx, sizeof tx, tmp, n);
181 vals[n] = tmp[n]; /* expand to 16bit */
186 static int mcp23s17_read(struct mcp23s08 *mcp, unsigned reg)
191 tx[0] = mcp->addr | 0x01;
193 status = spi_write_then_read(mcp->data, tx, sizeof tx, rx, sizeof rx);
194 return (status < 0) ? status : (rx[0] | (rx[1] << 8));
197 static int mcp23s17_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
205 return spi_write_then_read(mcp->data, tx, sizeof tx, NULL, 0);
209 mcp23s17_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
214 if ((n + reg) > sizeof mcp->cache)
216 tx[0] = mcp->addr | 0x01;
219 status = spi_write_then_read(mcp->data, tx, sizeof tx,
223 vals[n] = __le16_to_cpu((__le16)vals[n]);
229 static const struct mcp23s08_ops mcp23s08_ops = {
230 .read = mcp23s08_read,
231 .write = mcp23s08_write,
232 .read_regs = mcp23s08_read_regs,
235 static const struct mcp23s08_ops mcp23s17_ops = {
236 .read = mcp23s17_read,
237 .write = mcp23s17_write,
238 .read_regs = mcp23s17_read_regs,
241 #endif /* CONFIG_SPI_MASTER */
243 /*----------------------------------------------------------------------*/
245 static int mcp23s08_direction_input(struct gpio_chip *chip, unsigned offset)
247 struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
250 mutex_lock(&mcp->lock);
251 mcp->cache[MCP_IODIR] |= (1 << offset);
252 status = mcp->ops->write(mcp, MCP_IODIR, mcp->cache[MCP_IODIR]);
253 mutex_unlock(&mcp->lock);
257 static int mcp23s08_get(struct gpio_chip *chip, unsigned offset)
259 struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
262 mutex_lock(&mcp->lock);
264 /* REVISIT reading this clears any IRQ ... */
265 status = mcp->ops->read(mcp, MCP_GPIO);
269 mcp->cache[MCP_GPIO] = status;
270 status = !!(status & (1 << offset));
272 mutex_unlock(&mcp->lock);
276 static int __mcp23s08_set(struct mcp23s08 *mcp, unsigned mask, int value)
278 unsigned olat = mcp->cache[MCP_OLAT];
284 mcp->cache[MCP_OLAT] = olat;
285 return mcp->ops->write(mcp, MCP_OLAT, olat);
288 static void mcp23s08_set(struct gpio_chip *chip, unsigned offset, int value)
290 struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
291 unsigned mask = 1 << offset;
293 mutex_lock(&mcp->lock);
294 __mcp23s08_set(mcp, mask, value);
295 mutex_unlock(&mcp->lock);
299 mcp23s08_direction_output(struct gpio_chip *chip, unsigned offset, int value)
301 struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
302 unsigned mask = 1 << offset;
305 mutex_lock(&mcp->lock);
306 status = __mcp23s08_set(mcp, mask, value);
308 mcp->cache[MCP_IODIR] &= ~mask;
309 status = mcp->ops->write(mcp, MCP_IODIR, mcp->cache[MCP_IODIR]);
311 mutex_unlock(&mcp->lock);
315 /*----------------------------------------------------------------------*/
317 #ifdef CONFIG_DEBUG_FS
319 #include <linux/seq_file.h>
322 * This shows more info than the generic gpio dump code:
323 * pullups, deglitching, open drain drive.
325 static void mcp23s08_dbg_show(struct seq_file *s, struct gpio_chip *chip)
327 struct mcp23s08 *mcp;
332 mcp = container_of(chip, struct mcp23s08, chip);
334 /* NOTE: we only handle one bank for now ... */
335 bank = '0' + ((mcp->addr >> 1) & 0x7);
337 mutex_lock(&mcp->lock);
338 t = mcp->ops->read_regs(mcp, 0, mcp->cache, ARRAY_SIZE(mcp->cache));
340 seq_printf(s, " I/O ERROR %d\n", t);
344 for (t = 0, mask = 1; t < chip->ngpio; t++, mask <<= 1) {
347 label = gpiochip_is_requested(chip, t);
351 seq_printf(s, " gpio-%-3d P%c.%d (%-12s) %s %s %s",
352 chip->base + t, bank, t, label,
353 (mcp->cache[MCP_IODIR] & mask) ? "in " : "out",
354 (mcp->cache[MCP_GPIO] & mask) ? "hi" : "lo",
355 (mcp->cache[MCP_GPPU] & mask) ? " " : "up");
356 /* NOTE: ignoring the irq-related registers */
360 mutex_unlock(&mcp->lock);
364 #define mcp23s08_dbg_show NULL
367 /*----------------------------------------------------------------------*/
369 static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
370 void *data, unsigned addr,
371 unsigned type, unsigned base, unsigned pullups)
375 mutex_init(&mcp->lock);
380 mcp->chip.direction_input = mcp23s08_direction_input;
381 mcp->chip.get = mcp23s08_get;
382 mcp->chip.direction_output = mcp23s08_direction_output;
383 mcp->chip.set = mcp23s08_set;
384 mcp->chip.dbg_show = mcp23s08_dbg_show;
387 #ifdef CONFIG_SPI_MASTER
389 mcp->ops = &mcp23s08_ops;
391 mcp->chip.label = "mcp23s08";
395 mcp->ops = &mcp23s17_ops;
396 mcp->chip.ngpio = 16;
397 mcp->chip.label = "mcp23s17";
399 #endif /* CONFIG_SPI_MASTER */
403 mcp->ops = &mcp23008_ops;
405 mcp->chip.label = "mcp23008";
409 mcp->ops = &mcp23017_ops;
410 mcp->chip.ngpio = 16;
411 mcp->chip.label = "mcp23017";
413 #endif /* CONFIG_I2C */
416 dev_err(dev, "invalid device type (%d)\n", type);
420 mcp->chip.base = base;
421 mcp->chip.can_sleep = 1;
423 mcp->chip.owner = THIS_MODULE;
425 /* verify MCP_IOCON.SEQOP = 0, so sequential reads work,
426 * and MCP_IOCON.HAEN = 1, so we work with all chips.
428 status = mcp->ops->read(mcp, MCP_IOCON);
431 if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN)) {
432 /* mcp23s17 has IOCON twice, make sure they are in sync */
433 status &= ~(IOCON_SEQOP | (IOCON_SEQOP << 8));
434 status |= IOCON_HAEN | (IOCON_HAEN << 8);
435 status = mcp->ops->write(mcp, MCP_IOCON, status);
440 /* configure ~100K pullups */
441 status = mcp->ops->write(mcp, MCP_GPPU, pullups);
445 status = mcp->ops->read_regs(mcp, 0, mcp->cache, ARRAY_SIZE(mcp->cache));
449 /* disable inverter on input */
450 if (mcp->cache[MCP_IPOL] != 0) {
451 mcp->cache[MCP_IPOL] = 0;
452 status = mcp->ops->write(mcp, MCP_IPOL, 0);
458 if (mcp->cache[MCP_GPINTEN] != 0) {
459 mcp->cache[MCP_GPINTEN] = 0;
460 status = mcp->ops->write(mcp, MCP_GPINTEN, 0);
465 status = gpiochip_add(&mcp->chip);
468 dev_dbg(dev, "can't setup chip %d, --> %d\n",
473 /*----------------------------------------------------------------------*/
477 static int __devinit mcp230xx_probe(struct i2c_client *client,
478 const struct i2c_device_id *id)
480 struct mcp23s08_platform_data *pdata;
481 struct mcp23s08 *mcp;
484 pdata = client->dev.platform_data;
485 if (!pdata || !gpio_is_valid(pdata->base)) {
486 dev_dbg(&client->dev, "invalid or missing platform data\n");
490 mcp = kzalloc(sizeof *mcp, GFP_KERNEL);
494 status = mcp23s08_probe_one(mcp, &client->dev, client, client->addr,
495 id->driver_data, pdata->base,
496 pdata->chip[0].pullups);
500 i2c_set_clientdata(client, mcp);
510 static int __devexit mcp230xx_remove(struct i2c_client *client)
512 struct mcp23s08 *mcp = i2c_get_clientdata(client);
515 status = gpiochip_remove(&mcp->chip);
522 static const struct i2c_device_id mcp230xx_id[] = {
523 { "mcp23008", MCP_TYPE_008 },
524 { "mcp23017", MCP_TYPE_017 },
527 MODULE_DEVICE_TABLE(i2c, mcp230xx_id);
529 static struct i2c_driver mcp230xx_driver = {
532 .owner = THIS_MODULE,
534 .probe = mcp230xx_probe,
535 .remove = __devexit_p(mcp230xx_remove),
536 .id_table = mcp230xx_id,
539 static int __init mcp23s08_i2c_init(void)
541 return i2c_add_driver(&mcp230xx_driver);
544 static void mcp23s08_i2c_exit(void)
546 i2c_del_driver(&mcp230xx_driver);
551 static int __init mcp23s08_i2c_init(void) { return 0; }
552 static void mcp23s08_i2c_exit(void) { }
554 #endif /* CONFIG_I2C */
556 /*----------------------------------------------------------------------*/
558 #ifdef CONFIG_SPI_MASTER
560 static int mcp23s08_probe(struct spi_device *spi)
562 struct mcp23s08_platform_data *pdata;
565 struct mcp23s08_driver_data *data;
569 type = spi_get_device_id(spi)->driver_data;
571 pdata = spi->dev.platform_data;
572 if (!pdata || !gpio_is_valid(pdata->base)) {
573 dev_dbg(&spi->dev, "invalid or missing platform data\n");
577 for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
578 if (!pdata->chip[addr].is_present)
581 if ((type == MCP_TYPE_S08) && (addr > 3)) {
583 "mcp23s08 only supports address 0..3\n");
590 data = kzalloc(sizeof *data + chips * sizeof(struct mcp23s08),
594 spi_set_drvdata(spi, data);
597 for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
598 if (!pdata->chip[addr].is_present)
601 data->mcp[addr] = &data->chip[chips];
602 status = mcp23s08_probe_one(data->mcp[addr], &spi->dev, spi,
603 0x40 | (addr << 1), type, base,
604 pdata->chip[addr].pullups);
608 base += (type == MCP_TYPE_S17) ? 16 : 8;
610 data->ngpio = base - pdata->base;
612 /* NOTE: these chips have a relatively sane IRQ framework, with
613 * per-signal masking and level/edge triggering. It's not yet
620 for (addr = 0; addr < ARRAY_SIZE(data->mcp); addr++) {
623 if (!data->mcp[addr])
625 tmp = gpiochip_remove(&data->mcp[addr]->chip);
627 dev_err(&spi->dev, "%s --> %d\n", "remove", tmp);
633 static int mcp23s08_remove(struct spi_device *spi)
635 struct mcp23s08_driver_data *data = spi_get_drvdata(spi);
639 for (addr = 0; addr < ARRAY_SIZE(data->mcp); addr++) {
642 if (!data->mcp[addr])
645 tmp = gpiochip_remove(&data->mcp[addr]->chip);
647 dev_err(&spi->dev, "%s --> %d\n", "remove", tmp);
656 static const struct spi_device_id mcp23s08_ids[] = {
657 { "mcp23s08", MCP_TYPE_S08 },
658 { "mcp23s17", MCP_TYPE_S17 },
661 MODULE_DEVICE_TABLE(spi, mcp23s08_ids);
663 static struct spi_driver mcp23s08_driver = {
664 .probe = mcp23s08_probe,
665 .remove = mcp23s08_remove,
666 .id_table = mcp23s08_ids,
669 .owner = THIS_MODULE,
673 static int __init mcp23s08_spi_init(void)
675 return spi_register_driver(&mcp23s08_driver);
678 static void mcp23s08_spi_exit(void)
680 spi_unregister_driver(&mcp23s08_driver);
685 static int __init mcp23s08_spi_init(void) { return 0; }
686 static void mcp23s08_spi_exit(void) { }
688 #endif /* CONFIG_SPI_MASTER */
690 /*----------------------------------------------------------------------*/
692 static int __init mcp23s08_init(void)
696 ret = mcp23s08_spi_init();
700 ret = mcp23s08_i2c_init();
711 /* register after spi/i2c postcore initcall and before
712 * subsys initcalls that may rely on these GPIOs
714 subsys_initcall(mcp23s08_init);
716 static void __exit mcp23s08_exit(void)
721 module_exit(mcp23s08_exit);
723 MODULE_LICENSE("GPL");