[linux-block.git] / drivers / gpio / mcp23s08.c

/*
 * mcp23s08.c - SPI gpio expander driver
 */

#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/workqueue.h>
#include <linux/mutex.h>
#include <linux/gpio.h>
#include <linux/spi/spi.h>
#include <linux/spi/mcp23s08.h>


/* Registers are all 8 bits wide.
 *
 * The mcp23s17 has twice as many bits, and can be configured to work
 * with either 16 bit registers or with two adjacent 8 bit banks.
 *
 * Also, there are I2C versions of both chips.
 */
#define MCP_IODIR	0x00		/* init/reset:  all ones */
#define MCP_IPOL	0x01
#define MCP_GPINTEN	0x02
#define MCP_DEFVAL	0x03
#define MCP_INTCON	0x04
#define MCP_IOCON	0x05
#	define IOCON_SEQOP	(1 << 5)
#	define IOCON_HAEN	(1 << 3)
#	define IOCON_ODR	(1 << 2)
#	define IOCON_INTPOL	(1 << 1)
#define MCP_GPPU	0x06
#define MCP_INTF	0x07
#define MCP_INTCAP	0x08
#define MCP_GPIO	0x09
#define MCP_OLAT	0x0a

struct mcp23s08 {
	struct spi_device	*spi;
	u8			addr;

	u8			cache[11];
	/* lock protects the cached values */
	struct mutex		lock;

	struct gpio_chip	chip;

	struct work_struct	work;
};

/* A given spi_device can represent up to four mcp23s08 chips
 * sharing the same chipselect but using different addresses
 * (e.g. chips #0 and #3 might be populated, but not #1 or $2).
 * Driver data holds all the per-chip data.
 */
struct mcp23s08_driver_data {
	unsigned		ngpio;
	struct mcp23s08		*mcp[4];
	struct mcp23s08		chip[];
};

static int mcp23s08_read(struct mcp23s08 *mcp, unsigned reg)
{
	u8	tx[2], rx[1];
	int	status;

	tx[0] = mcp->addr | 0x01;
	tx[1] = reg;
	status = spi_write_then_read(mcp->spi, tx, sizeof tx, rx, sizeof rx);
	return (status < 0) ? status : rx[0];
}

static int mcp23s08_write(struct mcp23s08 *mcp, unsigned reg, u8 val)
{
	u8	tx[3];

	tx[0] = mcp->addr;
	tx[1] = reg;
	tx[2] = val;
	return spi_write_then_read(mcp->spi, tx, sizeof tx, NULL, 0);
}

static int
mcp23s08_read_regs(struct mcp23s08 *mcp, unsigned reg, u8 *vals, unsigned n)
{
	u8	tx[2];

	if ((n + reg) > sizeof mcp->cache)
		return -EINVAL;
	tx[0] = mcp->addr | 0x01;
	tx[1] = reg;
	return spi_write_then_read(mcp->spi, tx, sizeof tx, vals, n);
}

/*----------------------------------------------------------------------*/

static int mcp23s08_direction_input(struct gpio_chip *chip, unsigned offset)
{
	struct mcp23s08	*mcp = container_of(chip, struct mcp23s08, chip);
	int status;

	mutex_lock(&mcp->lock);
	mcp->cache[MCP_IODIR] |= (1 << offset);
	status = mcp23s08_write(mcp, MCP_IODIR, mcp->cache[MCP_IODIR]);
	mutex_unlock(&mcp->lock);
	return status;
}

static int mcp23s08_get(struct gpio_chip *chip, unsigned offset)
{
	struct mcp23s08	*mcp = container_of(chip, struct mcp23s08, chip);
	int status;

	mutex_lock(&mcp->lock);

	/* REVISIT reading this clears any IRQ ... */
	status = mcp23s08_read(mcp, MCP_GPIO);
	if (status < 0)
		status = 0;
	else {
		mcp->cache[MCP_GPIO] = status;
		status = !!(status & (1 << offset));
	}
	mutex_unlock(&mcp->lock);
	return status;
}

static int __mcp23s08_set(struct mcp23s08 *mcp, unsigned mask, int value)
{
	u8 olat = mcp->cache[MCP_OLAT];

	if (value)
		olat |= mask;
	else
		olat &= ~mask;
	mcp->cache[MCP_OLAT] = olat;
	return mcp23s08_write(mcp, MCP_OLAT, olat);
}

static void mcp23s08_set(struct gpio_chip *chip, unsigned offset, int value)
{
	struct mcp23s08	*mcp = container_of(chip, struct mcp23s08, chip);
	u8 mask = 1 << offset;

	mutex_lock(&mcp->lock);
	__mcp23s08_set(mcp, mask, value);
	mutex_unlock(&mcp->lock);
}

static int
mcp23s08_direction_output(struct gpio_chip *chip, unsigned offset, int value)
{
	struct mcp23s08	*mcp = container_of(chip, struct mcp23s08, chip);
	u8 mask = 1 << offset;
	int status;

	mutex_lock(&mcp->lock);
	status = __mcp23s08_set(mcp, mask, value);
	if (status == 0) {
		mcp->cache[MCP_IODIR] &= ~mask;
		status = mcp23s08_write(mcp, MCP_IODIR, mcp->cache[MCP_IODIR]);
	}
	mutex_unlock(&mcp->lock);
	return status;
}

/*----------------------------------------------------------------------*/

#ifdef CONFIG_DEBUG_FS

#include <linux/seq_file.h>

/*
 * This shows more info than the generic gpio dump code:
 * pullups, deglitching, open drain drive.
 */
static void mcp23s08_dbg_show(struct seq_file *s, struct gpio_chip *chip)
{
	struct mcp23s08	*mcp;
	char		bank;
	int		t;
	unsigned	mask;

	mcp = container_of(chip, struct mcp23s08, chip);

	/* NOTE: we only handle one bank for now ... */
	bank = '0' + ((mcp->addr >> 1) & 0x3);

	mutex_lock(&mcp->lock);
	t = mcp23s08_read_regs(mcp, 0, mcp->cache, sizeof mcp->cache);
	if (t < 0) {
		seq_printf(s, " I/O ERROR %d\n", t);
		goto done;
	}

	for (t = 0, mask = 1; t < 8; t++, mask <<= 1) {
		const char	*label;

		label = gpiochip_is_requested(chip, t);
		if (!label)
			continue;

		seq_printf(s, " gpio-%-3d P%c.%d (%-12s) %s %s %s",
			chip->base + t, bank, t, label,
			(mcp->cache[MCP_IODIR] & mask) ? "in " : "out",
			(mcp->cache[MCP_GPIO] & mask) ? "hi" : "lo",
			(mcp->cache[MCP_GPPU] & mask) ? "  " : "up");
		/* NOTE:  ignoring the irq-related registers */
		seq_printf(s, "\n");
	}
done:
	mutex_unlock(&mcp->lock);
}

#else
#define mcp23s08_dbg_show	NULL
#endif

/*----------------------------------------------------------------------*/

static int mcp23s08_probe_one(struct spi_device *spi, unsigned addr,
		unsigned base, unsigned pullups)
{
	struct mcp23s08_driver_data	*data = spi_get_drvdata(spi);
	struct mcp23s08			*mcp = data->mcp[addr];
	int				status;
	int				do_update = 0;

	mutex_init(&mcp->lock);

	mcp->spi = spi;
	mcp->addr = 0x40 | (addr << 1);

	mcp->chip.label = "mcp23s08",

	mcp->chip.direction_input = mcp23s08_direction_input;
	mcp->chip.get = mcp23s08_get;
	mcp->chip.direction_output = mcp23s08_direction_output;
	mcp->chip.set = mcp23s08_set;
	mcp->chip.dbg_show = mcp23s08_dbg_show;

	mcp->chip.base = base;
	mcp->chip.ngpio = 8;
	mcp->chip.can_sleep = 1;
	mcp->chip.dev = &spi->dev;
	mcp->chip.owner = THIS_MODULE;

	/* verify MCP_IOCON.SEQOP = 0, so sequential reads work,
	 * and MCP_IOCON.HAEN = 1, so we work with all chips.
	 */
	status = mcp23s08_read(mcp, MCP_IOCON);
	if (status < 0)
		goto fail;
	if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN)) {
		status &= ~IOCON_SEQOP;
		status |= IOCON_HAEN;
		status = mcp23s08_write(mcp, MCP_IOCON, (u8) status);
		if (status < 0)
			goto fail;
	}

	/* configure ~100K pullups */
	status = mcp23s08_write(mcp, MCP_GPPU, pullups);
	if (status < 0)
		goto fail;

	status = mcp23s08_read_regs(mcp, 0, mcp->cache, sizeof mcp->cache);
	if (status < 0)
		goto fail;

	/* disable inverter on input */
	if (mcp->cache[MCP_IPOL] != 0) {
		mcp->cache[MCP_IPOL] = 0;
		do_update = 1;
	}

	/* disable irqs */
	if (mcp->cache[MCP_GPINTEN] != 0) {
		mcp->cache[MCP_GPINTEN] = 0;
		do_update = 1;
	}

	if (do_update) {
		u8 tx[4];

		tx[0] = mcp->addr;
		tx[1] = MCP_IPOL;
		memcpy(&tx[2], &mcp->cache[MCP_IPOL], sizeof(tx) - 2);
		status = spi_write_then_read(mcp->spi, tx, sizeof tx, NULL, 0);
		if (status < 0)
			goto fail;
	}

	status = gpiochip_add(&mcp->chip);
fail:
	if (status < 0)
		dev_dbg(&spi->dev, "can't setup chip %d, --> %d\n",
				addr, status);
	return status;
}

static int mcp23s08_probe(struct spi_device *spi)
{
	struct mcp23s08_platform_data	*pdata;
	unsigned			addr;
	unsigned			chips = 0;
	struct mcp23s08_driver_data	*data;
	int				status;
	unsigned			base;

	pdata = spi->dev.platform_data;
	if (!pdata || !gpio_is_valid(pdata->base)) {
		dev_dbg(&spi->dev, "invalid or missing platform data\n");
		return -EINVAL;
	}

	for (addr = 0; addr < 4; addr++) {
		if (!pdata->chip[addr].is_present)
			continue;
		chips++;
	}
	if (!chips)
		return -ENODEV;

	data = kzalloc(sizeof *data + chips * sizeof(struct mcp23s08),
			GFP_KERNEL);
	if (!data)
		return -ENOMEM;
	spi_set_drvdata(spi, data);

	base = pdata->base;
	for (addr = 0; addr < 4; addr++) {
		if (!pdata->chip[addr].is_present)
			continue;
		chips--;
		data->mcp[addr] = &data->chip[chips];
		status = mcp23s08_probe_one(spi, addr, base,
				pdata->chip[addr].pullups);
		if (status < 0)
			goto fail;
		base += 8;
	}
	data->ngpio = base - pdata->base;

	/* NOTE:  these chips have a relatively sane IRQ framework, with
	 * per-signal masking and level/edge triggering.  It's not yet
	 * handled here...
	 */

	if (pdata->setup) {
		status = pdata->setup(spi,
				pdata->base, data->ngpio,
				pdata->context);
		if (status < 0)
			dev_dbg(&spi->dev, "setup --> %d\n", status);
	}

	return 0;

fail:
	for (addr = 0; addr < 4; addr++) {
		int tmp;

		if (!data->mcp[addr])
			continue;
		tmp = gpiochip_remove(&data->mcp[addr]->chip);
		if (tmp < 0)
			dev_err(&spi->dev, "%s --> %d\n", "remove", tmp);
	}
	kfree(data);
	return status;
}

static int mcp23s08_remove(struct spi_device *spi)
{
	struct mcp23s08_driver_data	*data = spi_get_drvdata(spi);
	struct mcp23s08_platform_data	*pdata = spi->dev.platform_data;
	unsigned			addr;
	int				status = 0;

	if (pdata->teardown) {
		status = pdata->teardown(spi,
				pdata->base, data->ngpio,
				pdata->context);
		if (status < 0) {
			dev_err(&spi->dev, "%s --> %d\n", "teardown", status);
			return status;
		}
	}

	for (addr = 0; addr < 4; addr++) {
		int tmp;

		if (!data->mcp[addr])
			continue;

		tmp = gpiochip_remove(&data->mcp[addr]->chip);
		if (tmp < 0) {
			dev_err(&spi->dev, "%s --> %d\n", "remove", tmp);
			status = tmp;
		}
	}
	if (status == 0)
		kfree(data);
	return status;
}

static struct spi_driver mcp23s08_driver = {
	.probe		= mcp23s08_probe,
	.remove		= mcp23s08_remove,
	.driver = {
		.name	= "mcp23s08",
		.owner	= THIS_MODULE,
	},
};

/*----------------------------------------------------------------------*/

static int __init mcp23s08_init(void)
{
	return spi_register_driver(&mcp23s08_driver);
}
/* register after spi postcore initcall and before
 * subsys initcalls that may rely on these GPIOs
 */
subsys_initcall(mcp23s08_init);

static void __exit mcp23s08_exit(void)
{
	spi_unregister_driver(&mcp23s08_driver);
}
module_exit(mcp23s08_exit);

MODULE_LICENSE("GPL");
MODULE_ALIAS("spi:mcp23s08");
Commit	Line	Data
e58b9e27 DB	1	/*
	2	* mcp23s08.c - SPI gpio expander driver
	3	*/
	4
	5	#include <linux/kernel.h>
	6	#include <linux/device.h>
	7	#include <linux/workqueue.h>
	8	#include <linux/mutex.h>
d120c17f	9	#include <linux/gpio.h>
e58b9e27 DB	10	#include <linux/spi/spi.h>
	11	#include <linux/spi/mcp23s08.h>
	12
e58b9e27 DB	13
	14	/* Registers are all 8 bits wide.
	15	*
	16	* The mcp23s17 has twice as many bits, and can be configured to work
	17	* with either 16 bit registers or with two adjacent 8 bit banks.
	18	*
	19	* Also, there are I2C versions of both chips.
	20	*/
	21	#define MCP_IODIR 0x00 /* init/reset: all ones */
	22	#define MCP_IPOL 0x01
	23	#define MCP_GPINTEN 0x02
	24	#define MCP_DEFVAL 0x03
	25	#define MCP_INTCON 0x04
	26	#define MCP_IOCON 0x05
	27	# define IOCON_SEQOP (1 << 5)
	28	# define IOCON_HAEN (1 << 3)
	29	# define IOCON_ODR (1 << 2)
	30	# define IOCON_INTPOL (1 << 1)
	31	#define MCP_GPPU 0x06
	32	#define MCP_INTF 0x07
	33	#define MCP_INTCAP 0x08
	34	#define MCP_GPIO 0x09
	35	#define MCP_OLAT 0x0a
	36
	37	struct mcp23s08 {
	38	struct spi_device *spi;
	39	u8 addr;
	40
8f1cc3b1	41	u8 cache[11];
e58b9e27 DB	42	/* lock protects the cached values */
e58b9e27 DB	43	struct mutex lock;
e58b9e27 DB	44
	45	struct gpio_chip chip;
	46
	47	struct work_struct work;
	48	};
	49
8f1cc3b1 DB	50	/* A given spi_device can represent up to four mcp23s08 chips
	51	* sharing the same chipselect but using different addresses
	52	* (e.g. chips #0 and #3 might be populated, but not #1 or $2).
	53	* Driver data holds all the per-chip data.
	54	*/
	55	struct mcp23s08_driver_data {
	56	unsigned ngpio;
	57	struct mcp23s08 *mcp[4];
	58	struct mcp23s08 chip[];
	59	};
	60
e58b9e27 DB	61	static int mcp23s08_read(struct mcp23s08 *mcp, unsigned reg)
	62	{
	63	u8 tx[2], rx[1];
	64	int status;
	65
	66	tx[0] = mcp->addr \| 0x01;
	67	tx[1] = reg;
	68	status = spi_write_then_read(mcp->spi, tx, sizeof tx, rx, sizeof rx);
	69	return (status < 0) ? status : rx[0];
	70	}
	71
	72	static int mcp23s08_write(struct mcp23s08 *mcp, unsigned reg, u8 val)
	73	{
	74	u8 tx[3];
	75
	76	tx[0] = mcp->addr;
	77	tx[1] = reg;
	78	tx[2] = val;
	79	return spi_write_then_read(mcp->spi, tx, sizeof tx, NULL, 0);
	80	}
	81
	82	static int
	83	mcp23s08_read_regs(struct mcp23s08 mcp, unsigned reg, u8 vals, unsigned n)
	84	{
	85	u8 tx[2];
	86
	87	if ((n + reg) > sizeof mcp->cache)
	88	return -EINVAL;
	89	tx[0] = mcp->addr \| 0x01;
	90	tx[1] = reg;
	91	return spi_write_then_read(mcp->spi, tx, sizeof tx, vals, n);
	92	}
	93
	94	/----------------------------------------------------------------------/
	95
	96	static int mcp23s08_direction_input(struct gpio_chip *chip, unsigned offset)
	97	{
	98	struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
	99	int status;
	100
	101	mutex_lock(&mcp->lock);
	102	mcp->cache[MCP_IODIR] \|= (1 << offset);
	103	status = mcp23s08_write(mcp, MCP_IODIR, mcp->cache[MCP_IODIR]);
	104	mutex_unlock(&mcp->lock);
	105	return status;
	106	}
	107
	108	static int mcp23s08_get(struct gpio_chip *chip, unsigned offset)
	109	{
	110	struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
	111	int status;
	112
	113	mutex_lock(&mcp->lock);
	114
	115	/* REVISIT reading this clears any IRQ ... */
	116	status = mcp23s08_read(mcp, MCP_GPIO);
	117	if (status < 0)
	118	status = 0;
	119	else {
	120	mcp->cache[MCP_GPIO] = status;
	121	status = !!(status & (1 << offset));
	122	}
	123	mutex_unlock(&mcp->lock);
	124	return status;
125	}
126
127	static int __mcp23s08_set(struct mcp23s08 *mcp, unsigned mask, int value)
128	{
129	u8 olat = mcp->cache[MCP_OLAT];
130
131	if (value)
132	olat \|= mask;
133	else
134	olat &= ~mask;
135	mcp->cache[MCP_OLAT] = olat;
136	return mcp23s08_write(mcp, MCP_OLAT, olat);
137	}
138
139	static void mcp23s08_set(struct gpio_chip *chip, unsigned offset, int value)
140	{
141	struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
142	u8 mask = 1 << offset;
143
144	mutex_lock(&mcp->lock);
145	__mcp23s08_set(mcp, mask, value);
146	mutex_unlock(&mcp->lock);
147	}
148
149	static int
150	mcp23s08_direction_output(struct gpio_chip *chip, unsigned offset, int value)
151	{
152	struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
153	u8 mask = 1 << offset;
154	int status;
155
156	mutex_lock(&mcp->lock);
157	status = __mcp23s08_set(mcp, mask, value);
158	if (status == 0) {
159	mcp->cache[MCP_IODIR] &= ~mask;
160	status = mcp23s08_write(mcp, MCP_IODIR, mcp->cache[MCP_IODIR]);
161	}
162	mutex_unlock(&mcp->lock);
163	return status;
164	}
165
166	/----------------------------------------------------------------------/
167
168	#ifdef CONFIG_DEBUG_FS
169
170	#include <linux/seq_file.h>
171
172	/*
173	* This shows more info than the generic gpio dump code:
174	* pullups, deglitching, open drain drive.
175	*/
176	static void mcp23s08_dbg_show(struct seq_file s, struct gpio_chip chip)
177	{
178	struct mcp23s08 *mcp;
179	char bank;
1d1c1d9b	180	int t;
e58b9e27 DB	181	unsigned mask;
	182
	183	mcp = container_of(chip, struct mcp23s08, chip);
	184
	185	/* NOTE: we only handle one bank for now ... */
	186	bank = '0' + ((mcp->addr >> 1) & 0x3);
	187
	188	mutex_lock(&mcp->lock);
	189	t = mcp23s08_read_regs(mcp, 0, mcp->cache, sizeof mcp->cache);
	190	if (t < 0) {
	191	seq_printf(s, " I/O ERROR %d\n", t);
	192	goto done;
	193	}
	194
	195	for (t = 0, mask = 1; t < 8; t++, mask <<= 1) {
	196	const char *label;
	197
	198	label = gpiochip_is_requested(chip, t);
	199	if (!label)
	200	continue;
	201
	202	seq_printf(s, " gpio-%-3d P%c.%d (%-12s) %s %s %s",
	203	chip->base + t, bank, t, label,
	204	(mcp->cache[MCP_IODIR] & mask) ? "in " : "out",
	205	(mcp->cache[MCP_GPIO] & mask) ? "hi" : "lo",
	206	(mcp->cache[MCP_GPPU] & mask) ? " " : "up");
	207	/* NOTE: ignoring the irq-related registers */
	208	seq_printf(s, "\n");
	209	}
	210	done:
	211	mutex_unlock(&mcp->lock);
	212	}
	213
	214	#else
	215	#define mcp23s08_dbg_show NULL
	216	#endif
	217
	218	/----------------------------------------------------------------------/
	219
8f1cc3b1 DB	220	static int mcp23s08_probe_one(struct spi_device *spi, unsigned addr,
8f1cc3b1 DB	221	unsigned base, unsigned pullups)
e58b9e27	222	{
8f1cc3b1 DB	223	struct mcp23s08_driver_data *data = spi_get_drvdata(spi);
8f1cc3b1 DB	224	struct mcp23s08 *mcp = data->mcp[addr];
e58b9e27 DB	225	int status;
	226	int do_update = 0;
	227
e58b9e27 DB	228	mutex_init(&mcp->lock);
	229
	230	mcp->spi = spi;
8f1cc3b1	231	mcp->addr = 0x40 \| (addr << 1);
e58b9e27 DB	232
	233	mcp->chip.label = "mcp23s08",
	234
	235	mcp->chip.direction_input = mcp23s08_direction_input;
	236	mcp->chip.get = mcp23s08_get;
	237	mcp->chip.direction_output = mcp23s08_direction_output;
	238	mcp->chip.set = mcp23s08_set;
	239	mcp->chip.dbg_show = mcp23s08_dbg_show;
	240
8f1cc3b1	241	mcp->chip.base = base;
e58b9e27 DB	242	mcp->chip.ngpio = 8;
e58b9e27 DB	243	mcp->chip.can_sleep = 1;
d8f388d8	244	mcp->chip.dev = &spi->dev;
d72cbed0	245	mcp->chip.owner = THIS_MODULE;
e58b9e27	246
8f1cc3b1 DB	247	/* verify MCP_IOCON.SEQOP = 0, so sequential reads work,
	248	* and MCP_IOCON.HAEN = 1, so we work with all chips.
	249	*/
e58b9e27 DB	250	status = mcp23s08_read(mcp, MCP_IOCON);
	251	if (status < 0)
	252	goto fail;
8f1cc3b1	253	if ((status & IOCON_SEQOP) \|\| !(status & IOCON_HAEN)) {
e58b9e27	254	status &= ~IOCON_SEQOP;
8f1cc3b1	255	status \|= IOCON_HAEN;
e58b9e27 DB	256	status = mcp23s08_write(mcp, MCP_IOCON, (u8) status);
	257	if (status < 0)
	258	goto fail;
	259	}
	260
	261	/* configure ~100K pullups */
8f1cc3b1	262	status = mcp23s08_write(mcp, MCP_GPPU, pullups);
e58b9e27 DB	263	if (status < 0)
	264	goto fail;
	265
	266	status = mcp23s08_read_regs(mcp, 0, mcp->cache, sizeof mcp->cache);
	267	if (status < 0)
	268	goto fail;
	269
	270	/* disable inverter on input */
	271	if (mcp->cache[MCP_IPOL] != 0) {
	272	mcp->cache[MCP_IPOL] = 0;
	273	do_update = 1;
	274	}
	275
	276	/* disable irqs */
	277	if (mcp->cache[MCP_GPINTEN] != 0) {
	278	mcp->cache[MCP_GPINTEN] = 0;
	279	do_update = 1;
	280	}
	281
	282	if (do_update) {
	283	u8 tx[4];
	284
	285	tx[0] = mcp->addr;
	286	tx[1] = MCP_IPOL;
	287	memcpy(&tx[2], &mcp->cache[MCP_IPOL], sizeof(tx) - 2);
	288	status = spi_write_then_read(mcp->spi, tx, sizeof tx, NULL, 0);
8f1cc3b1 DB	289	if (status < 0)
8f1cc3b1 DB	290	goto fail;
e58b9e27 DB	291	}
	292
	293	status = gpiochip_add(&mcp->chip);
8f1cc3b1 DB	294	fail:
	295	if (status < 0)
	296	dev_dbg(&spi->dev, "can't setup chip %d, --> %d\n",
	297	addr, status);
	298	return status;
	299	}
	300
	301	static int mcp23s08_probe(struct spi_device *spi)
	302	{
	303	struct mcp23s08_platform_data *pdata;
	304	unsigned addr;
	305	unsigned chips = 0;
	306	struct mcp23s08_driver_data *data;
	307	int status;
	308	unsigned base;
	309
	310	pdata = spi->dev.platform_data;
a342d215 BD	311	if (!pdata \|\| !gpio_is_valid(pdata->base)) {
	312	dev_dbg(&spi->dev, "invalid or missing platform data\n");
	313	return -EINVAL;
	314	}
8f1cc3b1 DB	315
	316	for (addr = 0; addr < 4; addr++) {
	317	if (!pdata->chip[addr].is_present)
	318	continue;
	319	chips++;
	320	}
	321	if (!chips)
	322	return -ENODEV;
	323
	324	data = kzalloc(sizeof data + chips sizeof(struct mcp23s08),
	325	GFP_KERNEL);
	326	if (!data)
	327	return -ENOMEM;
	328	spi_set_drvdata(spi, data);
	329
	330	base = pdata->base;
	331	for (addr = 0; addr < 4; addr++) {
	332	if (!pdata->chip[addr].is_present)
	333	continue;
	334	chips--;
	335	data->mcp[addr] = &data->chip[chips];
	336	status = mcp23s08_probe_one(spi, addr, base,
	337	pdata->chip[addr].pullups);
	338	if (status < 0)
	339	goto fail;
	340	base += 8;
	341	}
	342	data->ngpio = base - pdata->base;
e58b9e27 DB	343
	344	/* NOTE: these chips have a relatively sane IRQ framework, with
	345	* per-signal masking and level/edge triggering. It's not yet
	346	* handled here...
	347	*/
	348
	349	if (pdata->setup) {
8f1cc3b1 DB	350	status = pdata->setup(spi,
	351	pdata->base, data->ngpio,
	352	pdata->context);
e58b9e27 DB	353	if (status < 0)
	354	dev_dbg(&spi->dev, "setup --> %d\n", status);
	355	}
	356
	357	return 0;
	358
	359	fail:
8f1cc3b1 DB	360	for (addr = 0; addr < 4; addr++) {
	361	int tmp;
	362
	363	if (!data->mcp[addr])
	364	continue;
	365	tmp = gpiochip_remove(&data->mcp[addr]->chip);
	366	if (tmp < 0)
	367	dev_err(&spi->dev, "%s --> %d\n", "remove", tmp);
	368	}
	369	kfree(data);
e58b9e27 DB	370	return status;
	371	}
	372
	373	static int mcp23s08_remove(struct spi_device *spi)
	374	{
8f1cc3b1	375	struct mcp23s08_driver_data *data = spi_get_drvdata(spi);
e58b9e27	376	struct mcp23s08_platform_data *pdata = spi->dev.platform_data;
8f1cc3b1	377	unsigned addr;
e58b9e27 DB	378	int status = 0;
	379
	380	if (pdata->teardown) {
	381	status = pdata->teardown(spi,
8f1cc3b1	382	pdata->base, data->ngpio,
e58b9e27 DB	383	pdata->context);
	384	if (status < 0) {
	385	dev_err(&spi->dev, "%s --> %d\n", "teardown", status);
	386	return status;
	387	}
	388	}
	389
8f1cc3b1 DB	390	for (addr = 0; addr < 4; addr++) {
	391	int tmp;
	392
	393	if (!data->mcp[addr])
	394	continue;
	395
	396	tmp = gpiochip_remove(&data->mcp[addr]->chip);
	397	if (tmp < 0) {
	398	dev_err(&spi->dev, "%s --> %d\n", "remove", tmp);
	399	status = tmp;
	400	}
	401	}
e58b9e27	402	if (status == 0)
8f1cc3b1	403	kfree(data);
e58b9e27 DB	404	return status;
	405	}
	406
	407	static struct spi_driver mcp23s08_driver = {
	408	.probe = mcp23s08_probe,
	409	.remove = mcp23s08_remove,
	410	.driver = {
	411	.name = "mcp23s08",
	412	.owner = THIS_MODULE,
	413	},
	414	};
	415
	416	/----------------------------------------------------------------------/
	417
	418	static int __init mcp23s08_init(void)
	419	{
	420	return spi_register_driver(&mcp23s08_driver);
	421	}
673c0c00 DB	422	/* register after spi postcore initcall and before
	423	* subsys initcalls that may rely on these GPIOs
	424	*/
	425	subsys_initcall(mcp23s08_init);
e58b9e27 DB	426
	427	static void __exit mcp23s08_exit(void)
	428	{
	429	spi_unregister_driver(&mcp23s08_driver);
	430	}
	431	module_exit(mcp23s08_exit);
	432
	433	MODULE_LICENSE("GPL");
e0626e38	434	MODULE_ALIAS("spi:mcp23s08");