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authorJochen Friedrich <jochen@scram.de>2008-04-11 15:22:35 -0400
committerPaul Mackerras <paulus@samba.org>2008-04-16 17:46:11 -0400
commit612212a3f2f053ea68ce9cd16d3deeca7754e8c9 (patch)
tree90956837077b037215d4447e670e9a7e8426dedf /drivers/of
parentb7ce341585a51a6d65c7a77b6918132a3b360b81 (diff)
[POWERPC] i2c: OF helpers for the i2c API
This implements various helpers to support OF bindings for the i2c API. Signed-off-by: Jochen Friedrich <jochen@scram.de> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'drivers/of')
-rw-r--r--drivers/of/Kconfig6
-rw-r--r--drivers/of/Makefile1
-rw-r--r--drivers/of/i2c.c115
3 files changed, 122 insertions, 0 deletions
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index 3354ad766a49..7c305317f372 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -7,3 +7,9 @@ config OF_GPIO
7 depends on OF && PPC_OF && HAVE_GPIO_LIB 7 depends on OF && PPC_OF && HAVE_GPIO_LIB
8 help 8 help
9 OpenFirmware GPIO accessors 9 OpenFirmware GPIO accessors
10
11config OF_I2C
12 def_bool y
13 depends on OF && I2C
14 help
15 OpenFirmware I2C accessors
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index 5a61f70b4027..a07b95362c53 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -1,3 +1,4 @@
1obj-y = base.o 1obj-y = base.o
2obj-$(CONFIG_OF_DEVICE) += device.o platform.o 2obj-$(CONFIG_OF_DEVICE) += device.o platform.o
3obj-$(CONFIG_OF_GPIO) += gpio.o 3obj-$(CONFIG_OF_GPIO) += gpio.o
4obj-$(CONFIG_OF_I2C) += i2c.o
diff --git a/drivers/of/i2c.c b/drivers/of/i2c.c
new file mode 100644
index 000000000000..631689171159
--- /dev/null
+++ b/drivers/of/i2c.c
@@ -0,0 +1,115 @@
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
17struct i2c_driver_device {
18 char *of_device;
19 char *i2c_type;
20};
21
22static struct i2c_driver_device i2c_devices[] = {
23 { "dallas,ds1374", "rtc-ds1374" },
24};
25
26static 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
74void 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}
115EXPORT_SYMBOL(of_register_i2c_devices);