Commit 752ad5e8 authored by Peter Korsgaard's avatar Peter Korsgaard Committed by Grant Likely

mcp23s08: add i2c support

Add i2c bindings for the mcp230xx devices. This is quite a lot simpler
than the spi one as there's no funky sub addressing done (one struct
i2c_client per struct gpio_chip).

The mcp23s08_platform_data structure is reused for i2c, even though
only a single mcp23s08_chip_info structure is needed.

To use, simply fill out a platform_data structure and pass it in
i2c_board_info, E.G.:

static const struct mcp23s08_platform_data mcp23017_data = {
	.chip[0] = {
		.pullups = 0x00ff,
	},
	.base = 240,
};

static struct i2c_board_info __initdata i2c_devs[] = {
	{ I2C_BOARD_INFO("mcp23017", 0x20),
	  .platform_data = &smartview_mcp23017_data, },
	...
};
Signed-off-by: default avatarPeter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent d62b98f3
......@@ -412,10 +412,11 @@ config GPIO_MAX7301
GPIO driver for Maxim MAX7301 SPI-based GPIO expander.
config GPIO_MCP23S08
tristate "Microchip MCP23Sxx I/O expander"
depends on SPI_MASTER
tristate "Microchip MCP23xxx I/O expander"
depends on SPI_MASTER || I2C
help
SPI driver for Microchip MCP23S08/MPC23S17 I/O expanders.
SPI/I2C driver for Microchip MCP23S08/MCP23S17/MCP23008/MCP23017
I/O expanders.
This provides a GPIO interface supporting inputs and outputs.
config GPIO_MC33880
......
/*
* MCP23S08 SPI gpio expander driver
* MCP23S08 SPI/GPIO gpio expander driver
*/
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/gpio.h>
#include <linux/i2c.h>
#include <linux/spi/spi.h>
#include <linux/spi/mcp23s08.h>
#include <linux/slab.h>
......@@ -16,13 +17,13 @@
*/
#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.
*
* Also, there are I2C versions of both chips.
*/
#define MCP_IODIR 0x00 /* init/reset: all ones */
#define MCP_IPOL 0x01
......@@ -73,6 +74,72 @@ struct mcp23s08_driver_data {
struct mcp23s08 chip[];
};
/*----------------------------------------------------------------------*/
#ifdef 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)
......@@ -331,6 +398,20 @@ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
break;
#endif /* CONFIG_SPI_MASTER */
#ifdef 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;
......@@ -389,6 +470,91 @@ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
return status;
}
/*----------------------------------------------------------------------*/
#ifdef CONFIG_I2C
static int __devinit mcp230xx_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct mcp23s08_platform_data *pdata;
struct mcp23s08 *mcp;
int status;
pdata = client->dev.platform_data;
if (!pdata || !gpio_is_valid(pdata->base)) {
dev_dbg(&client->dev, "invalid or missing platform data\n");
return -EINVAL;
}
mcp = kzalloc(sizeof *mcp, GFP_KERNEL);
if (!mcp)
return -ENOMEM;
status = mcp23s08_probe_one(mcp, &client->dev, client, client->addr,
id->driver_data, pdata->base,
pdata->chip[0].pullups);
if (status)
goto fail;
i2c_set_clientdata(client, mcp);
return 0;
fail:
kfree(mcp);
return status;
}
static int __devexit 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,
},
.probe = mcp230xx_probe,
.remove = __devexit_p(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)
......@@ -525,9 +691,24 @@ static void mcp23s08_spi_exit(void) { }
static int __init mcp23s08_init(void)
{
return mcp23s08_spi_init();
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 postcore initcall and before
/* register after spi/i2c postcore initcall and before
* subsys initcalls that may rely on these GPIOs
*/
subsys_initcall(mcp23s08_init);
......@@ -535,6 +716,7 @@ subsys_initcall(mcp23s08_init);
static void __exit mcp23s08_exit(void)
{
mcp23s08_spi_exit();
mcp23s08_i2c_exit();
}
module_exit(mcp23s08_exit);
......
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