Commit 612212a3 authored by Jochen Friedrich's avatar Jochen Friedrich Committed by Paul Mackerras
Browse files

[POWERPC] i2c: OF helpers for the i2c API 



This implements various helpers to support OF bindings for the i2c
API.

Signed-off-by: default avatarJochen Friedrich <jochen@scram.de>
Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
Acked-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent b7ce3415

drivers/of/Kconfig

+6 −0
Original line number Diff line number Diff line
@@ -7,3 +7,9 @@ config OF_GPIO 
	depends on OF && PPC_OF && HAVE_GPIO_LIB

	help

	  OpenFirmware GPIO accessors



config OF_I2C

	def_bool y

	depends on OF && I2C

	help

	  OpenFirmware I2C accessors

drivers/of/Makefile

+1 −0
Original line number Diff line number Diff line 
obj-y = base.o

obj-$(CONFIG_OF_DEVICE) += device.o platform.o

obj-$(CONFIG_OF_GPIO)   += gpio.o

obj-$(CONFIG_OF_I2C)	+= i2c.o

drivers/of/i2c.c

0 → 100644
+115 −0
Original line number Diff line number Diff line 
/*

 * OF helpers for the I2C API

 *

 * Copyright (c) 2008 Jochen Friedrich <jochen@scram.de>

 *

 * Based on a previous patch from Jon Smirl <jonsmirl@gmail.com>

 *

 * 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.

 */



#include <linux/i2c.h>

#include <linux/of.h>



struct i2c_driver_device {

	char    *of_device;

	char    *i2c_type;

};



static struct i2c_driver_device i2c_devices[] = {

	{ "dallas,ds1374", "rtc-ds1374" },

};



static int of_find_i2c_driver(struct device_node *node,

			      struct i2c_board_info *info)

{

	int i, cplen;

	const char *compatible;

	const char *p;



	/* 1. search for exception list entry */

	for (i = 0; i < ARRAY_SIZE(i2c_devices); i++) {

		if (!of_device_is_compatible(node, i2c_devices[i].of_device))

			continue;

		if (strlcpy(info->type, i2c_devices[i].i2c_type,

			    I2C_NAME_SIZE) >= I2C_NAME_SIZE)

			return -ENOMEM;



		return 0;

	}



	compatible = of_get_property(node, "compatible", &cplen);

	if (!compatible)

		return -ENODEV;



	/* 2. search for linux,<i2c-type> entry */

	p = compatible;

	while (cplen > 0) {

		if (!strncmp(p, "linux,", 6)) {

			p += 6;

			if (strlcpy(info->type, p,

				    I2C_NAME_SIZE) >= I2C_NAME_SIZE)

				return -ENOMEM;

			return 0;

		}



		i = strlen(p) + 1;

		p += i;

		cplen -= i;

	}



	/* 3. take fist compatible entry and strip manufacturer */

	p = strchr(compatible, ',');

	if (!p)

		return -ENODEV;

	p++;

	if (strlcpy(info->type, p, I2C_NAME_SIZE) >= I2C_NAME_SIZE)

		return -ENOMEM;

	return 0;

}



void of_register_i2c_devices(struct i2c_adapter *adap,

			     struct device_node *adap_node)

{

	void *result;

	struct device_node *node;



	for_each_child_of_node(adap_node, node) {

		struct i2c_board_info info = {};

		const u32 *addr;

		int len;



		addr = of_get_property(node, "reg", &len);

		if (!addr || len < sizeof(int) || *addr > (1 << 10) - 1) {

			printk(KERN_ERR

			       "of-i2c: invalid i2c device entry\n");

			continue;

		}



		info.irq = irq_of_parse_and_map(node, 0);

		if (info.irq == NO_IRQ)

			info.irq = -1;



		if (of_find_i2c_driver(node, &info) < 0) {

			irq_dispose_mapping(info.irq);

			continue;

		}



		info.addr = *addr;



		request_module(info.type);



		result = i2c_new_device(adap, &info);

		if (result == NULL) {

			printk(KERN_ERR

			       "of-i2c: Failed to load driver for %s\n",

			       info.type);

			irq_dispose_mapping(info.irq);

			continue;

		}

	}

}

EXPORT_SYMBOL(of_register_i2c_devices);

include/linux/of_i2c.h

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Original line number Diff line number Diff line 
/*

 * Generic I2C API implementation for PowerPC.

 *

 * Copyright (c) 2008 Jochen Friedrich <jochen@scram.de>

 *

 * 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.

 */



#ifndef __LINUX_OF_I2C_H

#define __LINUX_OF_I2C_H



#include <linux/i2c.h>



#ifdef CONFIG_OF_I2C



void of_register_i2c_devices(struct i2c_adapter *adap,

			     struct device_node *adap_node);



#endif /* CONFIG_OF_I2C */



#endif /* __LINUX_OF_I2C_H */