u-boot/lib/acpi/acpi_device.c
Simon Glass 2715b3623c acpi: Add a way to check device status
At present U-Boot does not support the different ACPI status values, but
it is best to put this logic in a central place. Add a function to get the
device status.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-07-17 14:32:24 +08:00

88 lines
2 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Generation of tables for particular device types
*
* Copyright 2019 Google LLC
* Mostly taken from coreboot file of the same name
*/
#include <common.h>
#include <dm.h>
#include <log.h>
#include <acpi/acpi_device.h>
#include <dm/acpi.h>
/**
* acpi_device_path_fill() - Find the root device and build a path from there
*
* This recursively reaches back to the root device and progressively adds path
* elements until the device is reached.
*
* @dev: Device to return path of
* @buf: Buffer to hold the path
* @buf_len: Length of buffer
* @cur: Current position in the buffer
* @return new position in buffer after adding @dev, or -ve on error
*/
static int acpi_device_path_fill(const struct udevice *dev, char *buf,
size_t buf_len, int cur)
{
char name[ACPI_NAME_MAX];
int next = 0;
int ret;
ret = acpi_get_name(dev, name);
if (ret)
return ret;
/*
* Make sure this name segment will fit, including the path segment
* separator and possible NULL terminator, if this is the last segment.
*/
if (cur + strlen(name) + 2 > buf_len)
return -ENOSPC;
/* Walk up the tree to the root device */
if (dev_get_parent(dev)) {
next = acpi_device_path_fill(dev_get_parent(dev), buf, buf_len,
cur);
if (next < 0)
return next;
}
/* Fill in the path from the root device */
next += snprintf(buf + next, buf_len - next, "%s%s",
dev_get_parent(dev) && *name ? "." : "", name);
return next;
}
int acpi_device_path(const struct udevice *dev, char *buf, int maxlen)
{
int ret;
ret = acpi_device_path_fill(dev, buf, maxlen, 0);
if (ret < 0)
return ret;
return 0;
}
int acpi_device_scope(const struct udevice *dev, char *scope, int maxlen)
{
int ret;
if (!dev_get_parent(dev))
return log_msg_ret("noparent", -EINVAL);
ret = acpi_device_path_fill(dev_get_parent(dev), scope, maxlen, 0);
if (ret < 0)
return log_msg_ret("fill", ret);
return 0;
}
enum acpi_dev_status acpi_device_status(const struct udevice *dev)
{
return ACPI_DSTATUS_ALL_ON;
}