linux/drivers/of/of_i2c.c
Olof Johansson ee67016fcc of: i2c: add support for wakeup-source property
Add support for specifying a generic "wakeup-source" property on i2c
clients, which will set the I2C_CLIENT_WAKE flag, thus configuring the
device to wake the system from suspend (via IRQ).

This obviously doesn't make sense on devices lacking IRQ, but since we
still allow that in the i2c_board_info case, I don't see a reason to
restrict it here.

Note: Since the generic i2c bindings aren't documented in the kernel,
I didn't find a good place to add documentation for this binding
extension. I still think it makes sense to have a generic property
instead of having each device do its own binding for the same.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
2012-09-07 15:30:14 -05:00

115 lines
2.9 KiB
C

/*
* 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/irq.h>
#include <linux/of.h>
#include <linux/of_i2c.h>
#include <linux/of_irq.h>
#include <linux/module.h>
void of_i2c_register_devices(struct i2c_adapter *adap)
{
void *result;
struct device_node *node;
/* Only register child devices if the adapter has a node pointer set */
if (!adap->dev.of_node)
return;
dev_dbg(&adap->dev, "of_i2c: walking child nodes\n");
for_each_child_of_node(adap->dev.of_node, node) {
struct i2c_board_info info = {};
struct dev_archdata dev_ad = {};
const __be32 *addr;
int len;
dev_dbg(&adap->dev, "of_i2c: register %s\n", node->full_name);
if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) {
dev_err(&adap->dev, "of_i2c: modalias failure on %s\n",
node->full_name);
continue;
}
addr = of_get_property(node, "reg", &len);
if (!addr || (len < sizeof(int))) {
dev_err(&adap->dev, "of_i2c: invalid reg on %s\n",
node->full_name);
continue;
}
info.addr = be32_to_cpup(addr);
if (info.addr > (1 << 10) - 1) {
dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n",
info.addr, node->full_name);
continue;
}
info.irq = irq_of_parse_and_map(node, 0);
info.of_node = of_node_get(node);
info.archdata = &dev_ad;
if (of_get_property(node, "wakeup-source", NULL))
info.flags |= I2C_CLIENT_WAKE;
request_module("%s%s", I2C_MODULE_PREFIX, info.type);
result = i2c_new_device(adap, &info);
if (result == NULL) {
dev_err(&adap->dev, "of_i2c: Failure registering %s\n",
node->full_name);
of_node_put(node);
irq_dispose_mapping(info.irq);
continue;
}
}
}
EXPORT_SYMBOL(of_i2c_register_devices);
static int of_dev_node_match(struct device *dev, void *data)
{
return dev->of_node == data;
}
/* must call put_device() when done with returned i2c_client device */
struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
{
struct device *dev;
dev = bus_find_device(&i2c_bus_type, NULL, node,
of_dev_node_match);
if (!dev)
return NULL;
return i2c_verify_client(dev);
}
EXPORT_SYMBOL(of_find_i2c_device_by_node);
/* must call put_device() when done with returned i2c_adapter device */
struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
{
struct device *dev;
dev = bus_find_device(&i2c_bus_type, NULL, node,
of_dev_node_match);
if (!dev)
return NULL;
return i2c_verify_adapter(dev);
}
EXPORT_SYMBOL(of_find_i2c_adapter_by_node);
MODULE_LICENSE("GPL");