[deliverable/linux.git] / drivers / i2c / busses / i2c-parport-light.c

/* ------------------------------------------------------------------------ *
 * i2c-parport-light.c I2C bus over parallel port                           *
 * ------------------------------------------------------------------------ *
   Copyright (C) 2003-2007 Jean Delvare <khali@linux-fr.org>
   
   Based on older i2c-velleman.c driver
   Copyright (C) 1995-2000 Simon G. Vogl
   With some changes from:
   Frodo Looijaard <frodol@dds.nl>
   Kyösti Mälkki <kmalkki@cc.hut.fi>
   
   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, or
   (at your option) any later version.

   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., 675 Mass Ave, Cambridge, MA 02139, USA.
 * ------------------------------------------------------------------------ */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/ioport.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>
#include <asm/io.h>
#include "i2c-parport.h"

#define DEFAULT_BASE 0x378
#define DRVNAME "i2c-parport-light"

static struct platform_device *pdev;

static u16 base;
module_param(base, ushort, 0);
MODULE_PARM_DESC(base, "Base I/O address");

/* ----- Low-level parallel port access ----------------------------------- */

static inline void port_write(unsigned char p, unsigned char d)
{
	outb(d, base+p);
}

static inline unsigned char port_read(unsigned char p)
{
	return inb(base+p);
}

/* ----- Unified line operation functions --------------------------------- */

static inline void line_set(int state, const struct lineop *op)
{
	u8 oldval = port_read(op->port);

	/* Touch only the bit(s) needed */
	if ((op->inverted && !state) || (!op->inverted && state))
		port_write(op->port, oldval | op->val);
	else
		port_write(op->port, oldval & ~op->val);
}

static inline int line_get(const struct lineop *op)
{
	u8 oldval = port_read(op->port);

	return ((op->inverted && (oldval & op->val) != op->val)
	    || (!op->inverted && (oldval & op->val) == op->val));
}

/* ----- I2C algorithm call-back functions and structures ----------------- */

static void parport_setscl(void *data, int state)
{
	line_set(state, &adapter_parm[type].setscl);
}

static void parport_setsda(void *data, int state)
{
	line_set(state, &adapter_parm[type].setsda);
}

static int parport_getscl(void *data)
{
	return line_get(&adapter_parm[type].getscl);
}

static int parport_getsda(void *data)
{
	return line_get(&adapter_parm[type].getsda);
}

/* Encapsulate the functions above in the correct structure
   Note that getscl will be set to NULL by the attaching code for adapters
   that cannot read SCL back */
static struct i2c_algo_bit_data parport_algo_data = {
	.setsda		= parport_setsda,
	.setscl		= parport_setscl,
	.getsda		= parport_getsda,
	.getscl		= parport_getscl,
	.udelay		= 50,
	.timeout	= HZ,
}; 

/* ----- Driver registration ---------------------------------------------- */

static struct i2c_adapter parport_adapter = {
	.owner		= THIS_MODULE,
	.class		= I2C_CLASS_HWMON,
	.id		= I2C_HW_B_LP,
	.algo_data	= &parport_algo_data,
	.name		= "Parallel port adapter (light)",
};

static int __devinit i2c_parport_probe(struct platform_device *pdev)
{
	int err;
	struct resource *res;

	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
	if (!request_region(res->start, res->end - res->start + 1, DRVNAME))
		return -EBUSY;

	/* Reset hardware to a sane state (SCL and SDA high) */
	parport_setsda(NULL, 1);
	parport_setscl(NULL, 1);
	/* Other init if needed (power on...) */
	if (adapter_parm[type].init.val)
		line_set(1, &adapter_parm[type].init);

	parport_adapter.dev.parent = &pdev->dev;
	err = i2c_bit_add_bus(&parport_adapter);
	if (err) {
		dev_err(&pdev->dev, "Unable to register with I2C\n");
		goto exit_region;
	}
	return 0;

exit_region:
	release_region(res->start, res->end - res->start + 1);
	return err;
}

static int __devexit i2c_parport_remove(struct platform_device *pdev)
{
	struct resource *res;

	i2c_del_adapter(&parport_adapter);

	/* Un-init if needed (power off...) */
	if (adapter_parm[type].init.val)
		line_set(0, &adapter_parm[type].init);

	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
	release_region(res->start, res->end - res->start + 1);
	return 0;
}

static struct platform_driver i2c_parport_driver = {
	.driver = {
		.owner	= THIS_MODULE,
		.name	= DRVNAME,
	},
	.probe		= i2c_parport_probe,
	.remove		= __devexit_p(i2c_parport_remove),
};

static int __init i2c_parport_device_add(u16 address)
{
	struct resource res = {
		.start	= address,
		.end	= address + 2,
		.name	= DRVNAME,
		.flags	= IORESOURCE_IO,
	};
	int err;

	pdev = platform_device_alloc(DRVNAME, -1);
	if (!pdev) {
		err = -ENOMEM;
		printk(KERN_ERR DRVNAME ": Device allocation failed\n");
		goto exit;
	}

	err = platform_device_add_resources(pdev, &res, 1);
	if (err) {
		printk(KERN_ERR DRVNAME ": Device resource addition failed "
		       "(%d)\n", err);
		goto exit_device_put;
	}

	err = platform_device_add(pdev);
	if (err) {
		printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n",
		       err);
		goto exit_device_put;
	}

	return 0;

exit_device_put:
	platform_device_put(pdev);
exit:
	return err;
}

static int __init i2c_parport_init(void)
{
	int err;

	if (type < 0) {
		printk(KERN_ERR DRVNAME ": adapter type unspecified\n");
		return -ENODEV;
	}

	if (type >= ARRAY_SIZE(adapter_parm)) {
		printk(KERN_ERR DRVNAME ": invalid type (%d)\n", type);
		return -ENODEV;
	}

	if (base == 0) {
		pr_info(DRVNAME ": using default base 0x%x\n", DEFAULT_BASE);
		base = DEFAULT_BASE;
	}

        if (!adapter_parm[type].getscl.val)
		parport_algo_data.getscl = NULL;

	/* Sets global pdev as a side effect */
	err = i2c_parport_device_add(base);
	if (err)
		goto exit;

	err = platform_driver_register(&i2c_parport_driver);
	if (err)
		goto exit_device;

	return 0;

exit_device:
	platform_device_unregister(pdev);
exit:
	return err;
}

static void __exit i2c_parport_exit(void)
{
	platform_driver_unregister(&i2c_parport_driver);
	platform_device_unregister(pdev);
}

MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
MODULE_DESCRIPTION("I2C bus over parallel port (light)");
MODULE_LICENSE("GPL");

module_init(i2c_parport_init);
module_exit(i2c_parport_exit);
Commit	Line	Data
1da177e4	1	/* ------------------------------------------------------------------------ *
c6e8bb2c	2	* i2c-parport-light.c I2C bus over parallel port *
1da177e4	3	* ------------------------------------------------------------------------ *
c6e8bb2c	4	Copyright (C) 2003-2007 Jean Delvare <khali@linux-fr.org>
1da177e4 LT	5
	6	Based on older i2c-velleman.c driver
	7	Copyright (C) 1995-2000 Simon G. Vogl
	8	With some changes from:
	9	Frodo Looijaard <frodol@dds.nl>
96de0e25	10	Kyösti Mälkki <kmalkki@cc.hut.fi>
1da177e4 LT	11
	12	This program is free software; you can redistribute it and/or modify
	13	it under the terms of the GNU General Public License as published by
	14	the Free Software Foundation; either version 2 of the License, or
	15	(at your option) any later version.
	16
	17	This program is distributed in the hope that it will be useful,
	18	but WITHOUT ANY WARRANTY; without even the implied warranty of
	19	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	20	GNU General Public License for more details.
	21
	22	You should have received a copy of the GNU General Public License
	23	along with this program; if not, write to the Free Software
	24	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	25	* ------------------------------------------------------------------------ */
	26
1da177e4 LT	27	#include <linux/kernel.h>
	28	#include <linux/module.h>
	29	#include <linux/init.h>
c6e8bb2c	30	#include <linux/platform_device.h>
1da177e4 LT	31	#include <linux/ioport.h>
	32	#include <linux/i2c.h>
	33	#include <linux/i2c-algo-bit.h>
	34	#include <asm/io.h>
	35	#include "i2c-parport.h"
	36
	37	#define DEFAULT_BASE 0x378
c6e8bb2c JD	38	#define DRVNAME "i2c-parport-light"
	39
	40	static struct platform_device *pdev;
1da177e4 LT	41
	42	static u16 base;
	43	module_param(base, ushort, 0);
	44	MODULE_PARM_DESC(base, "Base I/O address");
	45
	46	/* ----- Low-level parallel port access ----------------------------------- */
	47
	48	static inline void port_write(unsigned char p, unsigned char d)
	49	{
	50	outb(d, base+p);
	51	}
	52
	53	static inline unsigned char port_read(unsigned char p)
	54	{
	55	return inb(base+p);
	56	}
	57
	58	/* ----- Unified line operation functions --------------------------------- */
	59
	60	static inline void line_set(int state, const struct lineop *op)
	61	{
	62	u8 oldval = port_read(op->port);
	63
	64	/* Touch only the bit(s) needed */
	65	if ((op->inverted && !state) \|\| (!op->inverted && state))
	66	port_write(op->port, oldval \| op->val);
	67	else
	68	port_write(op->port, oldval & ~op->val);
	69	}
	70
	71	static inline int line_get(const struct lineop *op)
	72	{
	73	u8 oldval = port_read(op->port);
	74
	75	return ((op->inverted && (oldval & op->val) != op->val)
	76	\|\| (!op->inverted && (oldval & op->val) == op->val));
	77	}
	78
	79	/* ----- I2C algorithm call-back functions and structures ----------------- */
	80
	81	static void parport_setscl(void *data, int state)
	82	{
	83	line_set(state, &adapter_parm[type].setscl);
	84	}
	85
	86	static void parport_setsda(void *data, int state)
	87	{
	88	line_set(state, &adapter_parm[type].setsda);
	89	}
	90
	91	static int parport_getscl(void *data)
	92	{
	93	return line_get(&adapter_parm[type].getscl);
	94	}
	95
	96	static int parport_getsda(void *data)
	97	{
	98	return line_get(&adapter_parm[type].getsda);
	99	}
	100
	101	/* Encapsulate the functions above in the correct structure
	102	Note that getscl will be set to NULL by the attaching code for adapters
	103	that cannot read SCL back */
	104	static struct i2c_algo_bit_data parport_algo_data = {
105	.setsda = parport_setsda,
106	.setscl = parport_setscl,
107	.getsda = parport_getsda,
108	.getscl = parport_getscl,
109	.udelay = 50,
1da177e4 LT	110	.timeout = HZ,
	111	};
	112
c6e8bb2c	113	/* ----- Driver registration ---------------------------------------------- */
1da177e4 LT	114
	115	static struct i2c_adapter parport_adapter = {
	116	.owner = THIS_MODULE,
	117	.class = I2C_CLASS_HWMON,
	118	.id = I2C_HW_B_LP,
	119	.algo_data = &parport_algo_data,
	120	.name = "Parallel port adapter (light)",
	121	};
	122
c6e8bb2c JD	123	static int __devinit i2c_parport_probe(struct platform_device *pdev)
	124	{
	125	int err;
	126	struct resource *res;
	127
	128	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
	129	if (!request_region(res->start, res->end - res->start + 1, DRVNAME))
	130	return -EBUSY;
	131
	132	/* Reset hardware to a sane state (SCL and SDA high) */
	133	parport_setsda(NULL, 1);
	134	parport_setscl(NULL, 1);
	135	/* Other init if needed (power on...) */
	136	if (adapter_parm[type].init.val)
	137	line_set(1, &adapter_parm[type].init);
	138
	139	parport_adapter.dev.parent = &pdev->dev;
	140	err = i2c_bit_add_bus(&parport_adapter);
	141	if (err) {
	142	dev_err(&pdev->dev, "Unable to register with I2C\n");
	143	goto exit_region;
	144	}
	145	return 0;
	146
	147	exit_region:
	148	release_region(res->start, res->end - res->start + 1);
	149	return err;
	150	}
	151
	152	static int __devexit i2c_parport_remove(struct platform_device *pdev)
	153	{
	154	struct resource *res;
	155
	156	i2c_del_adapter(&parport_adapter);
	157
	158	/* Un-init if needed (power off...) */
	159	if (adapter_parm[type].init.val)
	160	line_set(0, &adapter_parm[type].init);
	161
	162	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
	163	release_region(res->start, res->end - res->start + 1);
	164	return 0;
	165	}
	166
	167	static struct platform_driver i2c_parport_driver = {
	168	.driver = {
	169	.owner = THIS_MODULE,
	170	.name = DRVNAME,
	171	},
	172	.probe = i2c_parport_probe,
	173	.remove = __devexit_p(i2c_parport_remove),
	174	};
	175
	176	static int __init i2c_parport_device_add(u16 address)
	177	{
	178	struct resource res = {
	179	.start = address,
	180	.end = address + 2,
	181	.name = DRVNAME,
	182	.flags = IORESOURCE_IO,
	183	};
	184	int err;
	185
	186	pdev = platform_device_alloc(DRVNAME, -1);
187	if (!pdev) {
188	err = -ENOMEM;
189	printk(KERN_ERR DRVNAME ": Device allocation failed\n");
190	goto exit;
191	}
192
193	err = platform_device_add_resources(pdev, &res, 1);
194	if (err) {
195	printk(KERN_ERR DRVNAME ": Device resource addition failed "
196	"(%d)\n", err);
197	goto exit_device_put;
198	}
199
200	err = platform_device_add(pdev);
201	if (err) {
202	printk(KERN_ERR DRVNAME ": Device addition failed (%d)\n",
203	err);
204	goto exit_device_put;
205	}
206
207	return 0;
208
209	exit_device_put:
210	platform_device_put(pdev);
211	exit:
212	return err;
213	}
1da177e4 LT	214
	215	static int __init i2c_parport_init(void)
	216	{
c6e8bb2c JD	217	int err;
c6e8bb2c JD	218
e97b81dd	219	if (type < 0) {
c6e8bb2c	220	printk(KERN_ERR DRVNAME ": adapter type unspecified\n");
e97b81dd MH	221	return -ENODEV;
	222	}
	223
	224	if (type >= ARRAY_SIZE(adapter_parm)) {
c6e8bb2c	225	printk(KERN_ERR DRVNAME ": invalid type (%d)\n", type);
e97b81dd	226	return -ENODEV;
1da177e4	227	}
7e3d7db5	228
1da177e4	229	if (base == 0) {
c6e8bb2c	230	pr_info(DRVNAME ": using default base 0x%x\n", DEFAULT_BASE);
1da177e4 LT	231	base = DEFAULT_BASE;
	232	}
	233
1da177e4 LT	234	if (!adapter_parm[type].getscl.val)
	235	parport_algo_data.getscl = NULL;
	236
c6e8bb2c JD	237	/* Sets global pdev as a side effect */
	238	err = i2c_parport_device_add(base);
	239	if (err)
	240	goto exit;
1da177e4	241
c6e8bb2c JD	242	err = platform_driver_register(&i2c_parport_driver);
	243	if (err)
	244	goto exit_device;
7e3d7db5	245
1da177e4	246	return 0;
c6e8bb2c JD	247
	248	exit_device:
	249	platform_device_unregister(pdev);
	250	exit:
	251	return err;
1da177e4 LT	252	}
	253
	254	static void __exit i2c_parport_exit(void)
	255	{
c6e8bb2c JD	256	platform_driver_unregister(&i2c_parport_driver);
c6e8bb2c JD	257	platform_device_unregister(pdev);
1da177e4 LT	258	}
	259
	260	MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
	261	MODULE_DESCRIPTION("I2C bus over parallel port (light)");
	262	MODULE_LICENSE("GPL");
	263
	264	module_init(i2c_parport_init);
	265	module_exit(i2c_parport_exit);