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Commit bcda9f1e authored by Ben Dooks's avatar Ben Dooks Committed by Jean Delvare
Browse files

i2c: New Simtec I2C bus driver 



Platform driver for the Simtec CPLD based simple I2C logic.

Signed-off-by: default avatarBen Dooks <ben-linux@fluff.org>
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
parent 1c23af90

drivers/i2c/busses/Kconfig

+12 −0
Original line number Diff line number Diff line
@@ -413,6 +413,18 @@ config I2C_SIBYTE 
	help

	  Supports the SiByte SOC on-chip I2C interfaces (2 channels).



config I2C_SIMTEC

	tristate "Simtec Generic I2C interface"

	select I2C_ALGOBIT

	help

	  If you say yes to this option, support will be inclyded for

	  the Simtec Generic I2C interface. This driver is for the

	  simple I2C bus used on newer Simtec products for general

	  I2C, such as DDC on the Simtec BBD2016A.



	  This driver can also be build as a module. If so, the module

	  will be called i2c-simtec.



config SCx200_I2C

	tristate "NatSemi SCx200 I2C using GPIO pins"

	depends on SCx200_GPIO

drivers/i2c/busses/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ obj-$(CONFIG_I2C_RPXLITE) += i2c-rpx.o 
obj-$(CONFIG_I2C_S3C2410)	+= i2c-s3c2410.o

obj-$(CONFIG_I2C_SAVAGE4)	+= i2c-savage4.o

obj-$(CONFIG_I2C_SIBYTE)	+= i2c-sibyte.o

obj-$(CONFIG_I2C_SIMTEC)	+= i2c-simtec.o

obj-$(CONFIG_I2C_SIS5595)	+= i2c-sis5595.o

obj-$(CONFIG_I2C_SIS630)	+= i2c-sis630.o

obj-$(CONFIG_I2C_SIS96X)	+= i2c-sis96x.o

drivers/i2c/busses/i2c-simtec.c

0 → 100644
+186 −0
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2005 Simtec Electronics

 *	Ben Dooks <ben@simtec.co.uk>

 *

 * Simtec Generic I2C Controller

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

*/



#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/delay.h>

#include <linux/platform_device.h>



#include <linux/i2c.h>

#include <linux/i2c-algo-bit.h>



#include <asm/io.h>



struct simtec_i2c_data {

	struct resource		*ioarea;

	void __iomem		*reg;

	struct i2c_adapter	 adap;

	struct i2c_algo_bit_data bit;

};



#define CMD_SET_SDA	(1<<2)

#define CMD_SET_SCL	(1<<3)



#define STATE_SDA	(1<<0)

#define STATE_SCL	(1<<1)



/* i2c bit-bus functions */



static void simtec_i2c_setsda(void *pw, int state)

{

	struct simtec_i2c_data *pd = pw;

	writeb(CMD_SET_SDA | (state ? STATE_SDA : 0), pd->reg);

}



static void simtec_i2c_setscl(void *pw, int state)

{

	struct simtec_i2c_data *pd = pw;

	writeb(CMD_SET_SCL | (state ? STATE_SCL : 0), pd->reg);

}



static int simtec_i2c_getsda(void *pw)

{

	struct simtec_i2c_data *pd = pw;

	return readb(pd->reg) & STATE_SDA ? 1 : 0;

}



static int simtec_i2c_getscl(void *pw)

{

	struct simtec_i2c_data *pd = pw;

	return readb(pd->reg) & STATE_SCL ? 1 : 0;

}



/* device registration */



static int simtec_i2c_probe(struct platform_device *dev)

{

	struct simtec_i2c_data *pd;

	struct resource *res;

	int size;

	int ret;



	pd = kzalloc(sizeof(struct simtec_i2c_data), GFP_KERNEL);

	if (pd == NULL) {

		dev_err(&dev->dev, "cannot allocate private data\n");

		return -ENOMEM;

	}



	platform_set_drvdata(dev, pd);



	res = platform_get_resource(dev, IORESOURCE_MEM, 0);

	if (res == NULL) {

		dev_err(&dev->dev, "cannot find IO resource\n");

		ret = -ENOENT;

		goto err;

	}



	size = (res->end-res->start)+1;



	pd->ioarea = request_mem_region(res->start, size, dev->name);

	if (pd->ioarea == NULL) {

		dev_err(&dev->dev, "cannot request IO\n");

		ret = -ENXIO;

		goto err;

	}



	pd->reg = ioremap(res->start, size);

	if (pd->reg == NULL) {

		dev_err(&dev->dev, "cannot map IO\n");

		ret = -ENXIO;

		goto err_res;

	}



	/* setup the private data */



	pd->adap.owner = THIS_MODULE;

	pd->adap.algo_data = &pd->bit;

	pd->adap.dev.parent = &dev->dev;



	strlcpy(pd->adap.name, "Simtec I2C", sizeof(pd->adap.name));



	pd->bit.data = pd;

	pd->bit.setsda = simtec_i2c_setsda;

	pd->bit.setscl = simtec_i2c_setscl;

	pd->bit.getsda = simtec_i2c_getsda;

	pd->bit.getscl = simtec_i2c_getscl;

	pd->bit.timeout = HZ;

	pd->bit.udelay = 20;



	ret = i2c_bit_add_bus(&pd->adap);

	if (ret)

		goto err_all;



	return 0;



 err_all:

	iounmap(pd->reg);



 err_res:

	release_resource(pd->ioarea);

	kfree(pd->ioarea);



 err:

	kfree(pd);

	return ret;

}



static int simtec_i2c_remove(struct platform_device *dev)

{

	struct simtec_i2c_data *pd = platform_get_drvdata(dev);



	i2c_del_adapter(&pd->adap);



	iounmap(pd->reg);

	release_resource(pd->ioarea);

	kfree(pd->ioarea);

	kfree(pd);



	return 0;

}





/* device driver */



static struct platform_driver simtec_i2c_driver = {

	.driver		= {

		.name		= "simtec-i2c",

		.owner		= THIS_MODULE,

	},

	.probe		= simtec_i2c_probe,

	.remove		= simtec_i2c_remove,

};



static int __init i2c_adap_simtec_init(void)

{

	return platform_driver_register(&simtec_i2c_driver);

}



static void __exit i2c_adap_simtec_exit(void)

{

	platform_driver_unregister(&simtec_i2c_driver);

}



module_init(i2c_adap_simtec_init);

module_exit(i2c_adap_simtec_exit);



MODULE_DESCRIPTION("Simtec Generic I2C Bus driver");

MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");

MODULE_LICENSE("GPL");