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alistair23-linux/drivers/gpio/gpio-mcp23s08.c
Lars Poeschel 4597168696 gpio: mcp23s08: rename the device tree property 
The device tree property should be more descriptive.
microchip seems more reasonable than mcp. The old mcp
prefix is still supported but marked as deprecated.
Users of mcp have to switch to the microchip prefix.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-08-30 09:25:52 +02:00

826 lines
18 KiB
C
Raw Blame History

/*
* MCP23S08 SPI/GPIO gpio expander driver
*/
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/gpio.h>
#include <linux/i2c.h>
#include <linux/spi/spi.h>
#include <linux/spi/mcp23s08.h>
#include <linux/slab.h>
#include <asm/byteorder.h>
#include <linux/of.h>
#include <linux/of_device.h>
/**
* MCP types supported by driver
*/
#define MCP_TYPE_S08 0
#define MCP_TYPE_S17 1
#define MCP_TYPE_008 2
#define MCP_TYPE_017 3
/* 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.
*/
#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 mcp23s08_ops {
int (*read)(struct mcp23s08 *mcp, unsigned reg);
int (*write)(struct mcp23s08 *mcp, unsigned reg, unsigned val);
int (*read_regs)(struct mcp23s08 *mcp, unsigned reg,
u16 *vals, unsigned n);
};
struct mcp23s08 {
u8 addr;
u16 cache[11];
/* lock protects the cached values */
struct mutex lock;
struct gpio_chip chip;
const struct mcp23s08_ops *ops;
void *data; /* ops specific data */
};
/* A given spi_device can represent up to eight mcp23sxx 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[8];
struct mcp23s08 chip[];
};
/*----------------------------------------------------------------------*/
#if IS_ENABLED(CONFIG_I2C)
static int mcp23008_read(struct mcp23s08 *mcp, unsigned reg)
{
return i2c_smbus_read_byte_data(mcp->data, reg);
}
static int mcp23008_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
{
return i2c_smbus_write_byte_data(mcp->data, reg, val);
}
static int
mcp23008_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
{
while (n--) {
int ret = mcp23008_read(mcp, reg++);
if (ret < 0)
return ret;
*vals++ = ret;
}
return 0;
}
static int mcp23017_read(struct mcp23s08 *mcp, unsigned reg)
{
return i2c_smbus_read_word_data(mcp->data, reg << 1);
}
static int mcp23017_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
{
return i2c_smbus_write_word_data(mcp->data, reg << 1, val);
}
static int
mcp23017_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
{
while (n--) {
int ret = mcp23017_read(mcp, reg++);
if (ret < 0)
return ret;
*vals++ = ret;
}
return 0;
}
static const struct mcp23s08_ops mcp23008_ops = {
.read = mcp23008_read,
.write = mcp23008_write,
.read_regs = mcp23008_read_regs,
};
static const struct mcp23s08_ops mcp23017_ops = {
.read = mcp23017_read,
.write = mcp23017_write,
.read_regs = mcp23017_read_regs,
};
#endif /* CONFIG_I2C */
/*----------------------------------------------------------------------*/
#ifdef CONFIG_SPI_MASTER
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->data, tx, sizeof tx, rx, sizeof rx);
return (status < 0) ? status : rx[0];
}
static int mcp23s08_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
{
u8 tx[3];
tx[0] = mcp->addr;
tx[1] = reg;
tx[2] = val;
return spi_write_then_read(mcp->data, tx, sizeof tx, NULL, 0);
}
static int
mcp23s08_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
{
u8 tx[2], *tmp;
int status;
if ((n + reg) > sizeof mcp->cache)
return -EINVAL;
tx[0] = mcp->addr | 0x01;
tx[1] = reg;
tmp = (u8 *)vals;
status = spi_write_then_read(mcp->data, tx, sizeof tx, tmp, n);
if (status >= 0) {
while (n--)
vals[n] = tmp[n]; /* expand to 16bit */
}
return status;
}
static int mcp23s17_read(struct mcp23s08 *mcp, unsigned reg)
{
u8 tx[2], rx[2];
int status;
tx[0] = mcp->addr | 0x01;
tx[1] = reg << 1;
status = spi_write_then_read(mcp->data, tx, sizeof tx, rx, sizeof rx);
return (status < 0) ? status : (rx[0] | (rx[1] << 8));
}
static int mcp23s17_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
{
u8 tx[4];
tx[0] = mcp->addr;
tx[1] = reg << 1;
tx[2] = val;
tx[3] = val >> 8;
return spi_write_then_read(mcp->data, tx, sizeof tx, NULL, 0);
}
static int
mcp23s17_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
{
u8 tx[2];
int status;
if ((n + reg) > sizeof mcp->cache)
return -EINVAL;
tx[0] = mcp->addr | 0x01;
tx[1] = reg << 1;
status = spi_write_then_read(mcp->data, tx, sizeof tx,
(u8 *)vals, n * 2);
if (status >= 0) {
while (n--)
vals[n] = __le16_to_cpu((__le16)vals[n]);
}
return status;
}
static const struct mcp23s08_ops mcp23s08_ops = {
.read = mcp23s08_read,
.write = mcp23s08_write,
.read_regs = mcp23s08_read_regs,
};
static const struct mcp23s08_ops mcp23s17_ops = {
.read = mcp23s17_read,
.write = mcp23s17_write,
.read_regs = mcp23s17_read_regs,
};
#endif /* CONFIG_SPI_MASTER */
/*----------------------------------------------------------------------*/
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 = mcp->ops->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 = mcp->ops->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)
{
unsigned olat = mcp->cache[MCP_OLAT];
if (value)
olat |= mask;
else
olat &= ~mask;
mcp->cache[MCP_OLAT] = olat;
return mcp->ops->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);
unsigned 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);
unsigned mask = 1 << offset;
int status;
mutex_lock(&mcp->lock);
status = __mcp23s08_set(mcp, mask, value);
if (status == 0) {
mcp->cache[MCP_IODIR] &= ~mask;
status = mcp->ops->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) & 0x7);
mutex_lock(&mcp->lock);
t = mcp->ops->read_regs(mcp, 0, mcp->cache, ARRAY_SIZE(mcp->cache));
if (t < 0) {
seq_printf(s, " I/O ERROR %d\n", t);
goto done;
}
for (t = 0, mask = 1; t < chip->ngpio; 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 mcp23s08 *mcp, struct device *dev,
void *data, unsigned addr,
unsigned type, unsigned base, unsigned pullups)
{
int status;
mutex_init(&mcp->lock);
mcp->data = data;
mcp->addr = addr;
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;
#ifdef CONFIG_OF
mcp->chip.of_gpio_n_cells = 2;
mcp->chip.of_node = dev->of_node;
#endif
switch (type) {
#ifdef CONFIG_SPI_MASTER
case MCP_TYPE_S08:
mcp->ops = &mcp23s08_ops;
mcp->chip.ngpio = 8;
mcp->chip.label = "mcp23s08";
break;
case MCP_TYPE_S17:
mcp->ops = &mcp23s17_ops;
mcp->chip.ngpio = 16;
mcp->chip.label = "mcp23s17";
break;
#endif /* CONFIG_SPI_MASTER */
#if IS_ENABLED(CONFIG_I2C)
case MCP_TYPE_008:
mcp->ops = &mcp23008_ops;
mcp->chip.ngpio = 8;
mcp->chip.label = "mcp23008";
break;
case MCP_TYPE_017:
mcp->ops = &mcp23017_ops;
mcp->chip.ngpio = 16;
mcp->chip.label = "mcp23017";
break;
#endif /* CONFIG_I2C */
default:
dev_err(dev, "invalid device type (%d)\n", type);
return -EINVAL;
}
mcp->chip.base = base;
mcp->chip.can_sleep = 1;
mcp->chip.dev = 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 = mcp->ops->read(mcp, MCP_IOCON);
if (status < 0)
goto fail;
if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN)) {
/* mcp23s17 has IOCON twice, make sure they are in sync */
status &= ~(IOCON_SEQOP | (IOCON_SEQOP << 8));
status |= IOCON_HAEN | (IOCON_HAEN << 8);
status = mcp->ops->write(mcp, MCP_IOCON, status);
if (status < 0)
goto fail;
}
/* configure ~100K pullups */
status = mcp->ops->write(mcp, MCP_GPPU, pullups);
if (status < 0)
goto fail;
status = mcp->ops->read_regs(mcp, 0, mcp->cache, ARRAY_SIZE(mcp->cache));
if (status < 0)
goto fail;
/* disable inverter on input */
if (mcp->cache[MCP_IPOL] != 0) {
mcp->cache[MCP_IPOL] = 0;
status = mcp->ops->write(mcp, MCP_IPOL, 0);
if (status < 0)
goto fail;
}
/* disable irqs */
if (mcp->cache[MCP_GPINTEN] != 0) {
mcp->cache[MCP_GPINTEN] = 0;
status = mcp->ops->write(mcp, MCP_GPINTEN, 0);
if (status < 0)
goto fail;
}
status = gpiochip_add(&mcp->chip);
fail:
if (status < 0)
dev_dbg(dev, "can't setup chip %d, --> %d\n",
addr, status);
return status;
}
/*----------------------------------------------------------------------*/
#ifdef CONFIG_OF
#ifdef CONFIG_SPI_MASTER
static struct of_device_id mcp23s08_spi_of_match[] = {
{
.compatible = "microchip,mcp23s08",
.data = (void *) MCP_TYPE_S08,
},
{
.compatible = "microchip,mcp23s17",
.data = (void *) MCP_TYPE_S17,
},
/* NOTE: The use of the mcp prefix is deprecated and will be removed. */
{
.compatible = "mcp,mcp23s08",
.data = (void *) MCP_TYPE_S08,
},
{
.compatible = "mcp,mcp23s17",
.data = (void *) MCP_TYPE_S17,
},
{ },
};
MODULE_DEVICE_TABLE(of, mcp23s08_spi_of_match);
#endif
#if IS_ENABLED(CONFIG_I2C)
static struct of_device_id mcp23s08_i2c_of_match[] = {
{
.compatible = "microchip,mcp23008",
.data = (void *) MCP_TYPE_008,
},
{
.compatible = "microchip,mcp23017",
.data = (void *) MCP_TYPE_017,
},
/* NOTE: The use of the mcp prefix is deprecated and will be removed. */
{
.compatible = "mcp,mcp23008",
.data = (void *) MCP_TYPE_008,
},
{
.compatible = "mcp,mcp23017",
.data = (void *) MCP_TYPE_017,
},
{ },
};
MODULE_DEVICE_TABLE(of, mcp23s08_i2c_of_match);
#endif
#endif /* CONFIG_OF */
#if IS_ENABLED(CONFIG_I2C)
static int mcp230xx_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct mcp23s08_platform_data *pdata;
struct mcp23s08 *mcp;
int status, base, pullups;
const struct of_device_id *match;
match = of_match_device(of_match_ptr(mcp23s08_i2c_of_match),
&client->dev);
pdata = dev_get_platdata(&client->dev);
if (match || !pdata) {
base = -1;
pullups = 0;
} else {
if (!gpio_is_valid(pdata->base)) {
dev_dbg(&client->dev, "invalid platform data\n");
return -EINVAL;
}
base = pdata->base;
pullups = pdata->chip[0].pullups;
}
mcp = kzalloc(sizeof *mcp, GFP_KERNEL);
if (!mcp)
return -ENOMEM;
status = mcp23s08_probe_one(mcp, &client->dev, client, client->addr,
id->driver_data, base, pullups);
if (status)
goto fail;
i2c_set_clientdata(client, mcp);
return 0;
fail:
kfree(mcp);
return status;
}
static int mcp230xx_remove(struct i2c_client *client)
{
struct mcp23s08 *mcp = i2c_get_clientdata(client);
int status;
status = gpiochip_remove(&mcp->chip);
if (status == 0)
kfree(mcp);
return status;
}
static const struct i2c_device_id mcp230xx_id[] = {
{ "mcp23008", MCP_TYPE_008 },
{ "mcp23017", MCP_TYPE_017 },
{ },
};
MODULE_DEVICE_TABLE(i2c, mcp230xx_id);
static struct i2c_driver mcp230xx_driver = {
.driver = {
.name = "mcp230xx",
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(mcp23s08_i2c_of_match),
},
.probe = mcp230xx_probe,
.remove = mcp230xx_remove,
.id_table = mcp230xx_id,
};
static int __init mcp23s08_i2c_init(void)
{
return i2c_add_driver(&mcp230xx_driver);
}
static void mcp23s08_i2c_exit(void)
{
i2c_del_driver(&mcp230xx_driver);
}
#else
static int __init mcp23s08_i2c_init(void) { return 0; }
static void mcp23s08_i2c_exit(void) { }
#endif /* CONFIG_I2C */
/*----------------------------------------------------------------------*/
#ifdef CONFIG_SPI_MASTER
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, type;
unsigned base = -1,
ngpio = 0,
pullups[ARRAY_SIZE(pdata->chip)];
const struct of_device_id *match;
u32 spi_present_mask = 0;
match = of_match_device(of_match_ptr(mcp23s08_spi_of_match), &spi->dev);
if (match) {
type = (int)match->data;
status = of_property_read_u32(spi->dev.of_node,
"microchip,spi-present-mask", &spi_present_mask);
if (status) {
status = of_property_read_u32(spi->dev.of_node,
"mcp,spi-present-mask", &spi_present_mask);
if (status) {
dev_err(&spi->dev,
"DT has no spi-present-mask\n");
return -ENODEV;
}
}
if ((spi_present_mask <= 0) || (spi_present_mask >= 256)) {
dev_err(&spi->dev, "invalid spi-present-mask\n");
return -ENODEV;
}
for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++)
pullups[addr] = 0;
} else {
type = spi_get_device_id(spi)->driver_data;
pdata = dev_get_platdata(&spi->dev);
if (!pdata || !gpio_is_valid(pdata->base)) {
dev_dbg(&spi->dev,
"invalid or missing platform data\n");
return -EINVAL;
}
for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
if (!pdata->chip[addr].is_present)
continue;
chips++;
if ((type == MCP_TYPE_S08) && (addr > 3)) {
dev_err(&spi->dev,
"mcp23s08 only supports address 0..3\n");
return -EINVAL;
}
spi_present_mask |= 1 << addr;
pullups[addr] = pdata->chip[addr].pullups;
}
if (!chips)
return -ENODEV;
base = pdata->base;
}
data = kzalloc(sizeof *data + chips * sizeof(struct mcp23s08),
GFP_KERNEL);
if (!data)
return -ENOMEM;
spi_set_drvdata(spi, data);
for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
if (!(spi_present_mask & (1 << addr)))
continue;
chips--;
data->mcp[addr] = &data->chip[chips];
status = mcp23s08_probe_one(data->mcp[addr], &spi->dev, spi,
0x40 | (addr << 1), type, base,
pullups[addr]);
if (status < 0)
goto fail;
if (base != -1)
base += (type == MCP_TYPE_S17) ? 16 : 8;
ngpio += (type == MCP_TYPE_S17) ? 16 : 8;
}
data->ngpio = ngpio;
/* NOTE: these chips have a relatively sane IRQ framework, with
* per-signal masking and level/edge triggering. It's not yet
* handled here...
*/
return 0;
fail:
for (addr = 0; addr < ARRAY_SIZE(data->mcp); 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);
unsigned addr;
int status = 0;
for (addr = 0; addr < ARRAY_SIZE(data->mcp); 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 const struct spi_device_id mcp23s08_ids[] = {
{ "mcp23s08", MCP_TYPE_S08 },
{ "mcp23s17", MCP_TYPE_S17 },
{ },
};
MODULE_DEVICE_TABLE(spi, mcp23s08_ids);
static struct spi_driver mcp23s08_driver = {
.probe = mcp23s08_probe,
.remove = mcp23s08_remove,
.id_table = mcp23s08_ids,
.driver = {
.name = "mcp23s08",
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(mcp23s08_spi_of_match),
},
};
static int __init mcp23s08_spi_init(void)
{
return spi_register_driver(&mcp23s08_driver);
}
static void mcp23s08_spi_exit(void)
{
spi_unregister_driver(&mcp23s08_driver);
}
#else
static int __init mcp23s08_spi_init(void) { return 0; }
static void mcp23s08_spi_exit(void) { }
#endif /* CONFIG_SPI_MASTER */
/*----------------------------------------------------------------------*/
static int __init mcp23s08_init(void)
{
int ret;
ret = mcp23s08_spi_init();
if (ret)
goto spi_fail;
ret = mcp23s08_i2c_init();
if (ret)
goto i2c_fail;
return 0;
i2c_fail:
mcp23s08_spi_exit();
spi_fail:
return ret;
}
/* register after spi/i2c postcore initcall and before
* subsys initcalls that may rely on these GPIOs
*/
subsys_initcall(mcp23s08_init);
static void __exit mcp23s08_exit(void)
{
mcp23s08_spi_exit();
mcp23s08_i2c_exit();
}
module_exit(mcp23s08_exit);
MODULE_LICENSE("GPL");
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