diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/of/Kconfig | 6 | ||||
| -rw-r--r-- | drivers/of/Makefile | 1 | ||||
| -rw-r--r-- | drivers/of/i2c.c | 115 |
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 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 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 @@ obj-y = base.o obj-$(CONFIG_OF_DEVICE) += device.o platform.o obj-$(CONFIG_OF_GPIO) += gpio.o +obj-$(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 @@ +/* + * 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); |