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/*
* 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>
#include <linux/module.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);
MODULE_LICENSE("GPL");
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