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

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

drivers/gpio/Kconfig

+4 −3
Original line number Diff line number Diff line
@@ -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

drivers/gpio/gpio-mcp23s08.c

+187 −5
Original line number Diff line number Diff line 
/*

 * 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 @@ fail: 
	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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