| Jochen Friedrich | 612212a | 2008-04-12 05:22:35 +1000 | [diff] [blame] | 1 | /* |
| 2 | * OF helpers for the I2C API |
| 3 | * |
| 4 | * Copyright (c) 2008 Jochen Friedrich <jochen@scram.de> |
| 5 | * |
| 6 | * Based on a previous patch from Jon Smirl <jonsmirl@gmail.com> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; either version 2 of the License, or |
| 11 | * (at your option) any later version. |
| 12 | */ |
| 13 | |
| 14 | #include <linux/i2c.h> |
| 15 | #include <linux/of.h> |
| 16 | |
| 17 | struct i2c_driver_device { |
| 18 | char *of_device; |
| 19 | char *i2c_type; |
| 20 | }; |
| 21 | |
| 22 | static struct i2c_driver_device i2c_devices[] = { |
| 23 | { "dallas,ds1374", "rtc-ds1374" }, |
| 24 | }; |
| 25 | |
| 26 | static int of_find_i2c_driver(struct device_node *node, |
| 27 | struct i2c_board_info *info) |
| 28 | { |
| 29 | int i, cplen; |
| 30 | const char *compatible; |
| 31 | const char *p; |
| 32 | |
| 33 | /* 1. search for exception list entry */ |
| 34 | for (i = 0; i < ARRAY_SIZE(i2c_devices); i++) { |
| 35 | if (!of_device_is_compatible(node, i2c_devices[i].of_device)) |
| 36 | continue; |
| 37 | if (strlcpy(info->type, i2c_devices[i].i2c_type, |
| 38 | I2C_NAME_SIZE) >= I2C_NAME_SIZE) |
| 39 | return -ENOMEM; |
| 40 | |
| 41 | return 0; |
| 42 | } |
| 43 | |
| 44 | compatible = of_get_property(node, "compatible", &cplen); |
| 45 | if (!compatible) |
| 46 | return -ENODEV; |
| 47 | |
| 48 | /* 2. search for linux,<i2c-type> entry */ |
| 49 | p = compatible; |
| 50 | while (cplen > 0) { |
| 51 | if (!strncmp(p, "linux,", 6)) { |
| 52 | p += 6; |
| 53 | if (strlcpy(info->type, p, |
| 54 | I2C_NAME_SIZE) >= I2C_NAME_SIZE) |
| 55 | return -ENOMEM; |
| 56 | return 0; |
| 57 | } |
| 58 | |
| 59 | i = strlen(p) + 1; |
| 60 | p += i; |
| 61 | cplen -= i; |
| 62 | } |
| 63 | |
| 64 | /* 3. take fist compatible entry and strip manufacturer */ |
| 65 | p = strchr(compatible, ','); |
| 66 | if (!p) |
| 67 | return -ENODEV; |
| 68 | p++; |
| 69 | if (strlcpy(info->type, p, I2C_NAME_SIZE) >= I2C_NAME_SIZE) |
| 70 | return -ENOMEM; |
| 71 | return 0; |
| 72 | } |
| 73 | |
| 74 | void of_register_i2c_devices(struct i2c_adapter *adap, |
| 75 | struct device_node *adap_node) |
| 76 | { |
| 77 | void *result; |
| 78 | struct device_node *node; |
| 79 | |
| 80 | for_each_child_of_node(adap_node, node) { |
| 81 | struct i2c_board_info info = {}; |
| 82 | const u32 *addr; |
| 83 | int len; |
| 84 | |
| 85 | addr = of_get_property(node, "reg", &len); |
| 86 | if (!addr || len < sizeof(int) || *addr > (1 << 10) - 1) { |
| 87 | printk(KERN_ERR |
| 88 | "of-i2c: invalid i2c device entry\n"); |
| 89 | continue; |
| 90 | } |
| 91 | |
| 92 | info.irq = irq_of_parse_and_map(node, 0); |
| 93 | if (info.irq == NO_IRQ) |
| 94 | info.irq = -1; |
| 95 | |
| 96 | if (of_find_i2c_driver(node, &info) < 0) { |
| 97 | irq_dispose_mapping(info.irq); |
| 98 | continue; |
| 99 | } |
| 100 | |
| 101 | info.addr = *addr; |
| 102 | |
| 103 | request_module(info.type); |
| 104 | |
| 105 | result = i2c_new_device(adap, &info); |
| 106 | if (result == NULL) { |
| 107 | printk(KERN_ERR |
| 108 | "of-i2c: Failed to load driver for %s\n", |
| 109 | info.type); |
| 110 | irq_dispose_mapping(info.irq); |
| 111 | continue; |
| 112 | } |
| 113 | } |
| 114 | } |
| 115 | EXPORT_SYMBOL(of_register_i2c_devices); |