drivers/base: add bus for System-on-Chip devices
Traditionally, any System-on-Chip based platform creates a flat list of platform_devices directly under /sys/devices/platform. In order to give these some better structure, this introduces a new bus type for soc_devices that are registered with the new soc_device_register() function. All devices that are on the same chip should then be registered as child devices of the soc device. The soc bus also exports a few standardised device attributes which allow user space to query the specific type of soc. Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Lee Jones
Greg Kroah-Hartman
parent
956563362b
commit
74d1d82cda
@ -176,6 +176,9 @@ config GENERIC_CPU_DEVICES
|
||||
bool
|
||||
default n
|
||||
|
||||
config SOC_BUS
|
||||
bool
|
||||
|
||||
source "drivers/base/regmap/Kconfig"
|
||||
|
||||
config DMA_SHARED_BUFFER
|
||||
|
||||
@ -19,6 +19,7 @@ obj-$(CONFIG_MODULES) += module.o
|
||||
endif
|
||||
obj-$(CONFIG_SYS_HYPERVISOR) += hypervisor.o
|
||||
obj-$(CONFIG_REGMAP) += regmap/
|
||||
obj-$(CONFIG_SOC_BUS) += soc.o
|
||||
|
||||
ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG
|
||||
|
||||
|
||||
183
drivers/base/soc.c
Normal file
183
drivers/base/soc.c
Normal file
@ -0,0 +1,183 @@
|
||||
/*
|
||||
* Copyright (C) ST-Ericsson SA 2011
|
||||
*
|
||||
* Author: Lee Jones <lee.jones@linaro.org> for ST-Ericsson.
|
||||
* License terms: GNU General Public License (GPL), version 2
|
||||
*/
|
||||
|
||||
#include <linux/sysfs.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/init.h>
|
||||
#include <linux/stat.h>
|
||||
#include <linux/slab.h>
|
||||
#include <linux/idr.h>
|
||||
#include <linux/spinlock.h>
|
||||
#include <linux/sys_soc.h>
|
||||
#include <linux/err.h>
|
||||
|
||||
static DEFINE_IDR(soc_ida);
|
||||
static DEFINE_SPINLOCK(soc_lock);
|
||||
|
||||
static ssize_t soc_info_get(struct device *dev,
|
||||
struct device_attribute *attr,
|
||||
char *buf);
|
||||
|
||||
struct soc_device {
|
||||
struct device dev;
|
||||
struct soc_device_attribute *attr;
|
||||
int soc_dev_num;
|
||||
};
|
||||
|
||||
static struct bus_type soc_bus_type = {
|
||||
.name = "soc",
|
||||
};
|
||||
|
||||
static DEVICE_ATTR(machine, S_IRUGO, soc_info_get, NULL);
|
||||
static DEVICE_ATTR(family, S_IRUGO, soc_info_get, NULL);
|
||||
static DEVICE_ATTR(soc_id, S_IRUGO, soc_info_get, NULL);
|
||||
static DEVICE_ATTR(revision, S_IRUGO, soc_info_get, NULL);
|
||||
|
||||
struct device *soc_device_to_device(struct soc_device *soc_dev)
|
||||
{
|
||||
return &soc_dev->dev;
|
||||
}
|
||||
|
||||
static mode_t soc_attribute_mode(struct kobject *kobj,
|
||||
struct attribute *attr,
|
||||
int index)
|
||||
{
|
||||
struct device *dev = container_of(kobj, struct device, kobj);
|
||||
struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
|
||||
|
||||
if ((attr == &dev_attr_machine.attr)
|
||||
&& (soc_dev->attr->machine != NULL))
|
||||
return attr->mode;
|
||||
if ((attr == &dev_attr_family.attr)
|
||||
&& (soc_dev->attr->family != NULL))
|
||||
return attr->mode;
|
||||
if ((attr == &dev_attr_revision.attr)
|
||||
&& (soc_dev->attr->revision != NULL))
|
||||
return attr->mode;
|
||||
if ((attr == &dev_attr_soc_id.attr)
|
||||
&& (soc_dev->attr->soc_id != NULL))
|
||||
return attr->mode;
|
||||
|
||||
/* Unknown or unfilled attribute. */
|
||||
return 0;
|
||||
}
|
||||
|
||||
static ssize_t soc_info_get(struct device *dev,
|
||||
struct device_attribute *attr,
|
||||
char *buf)
|
||||
{
|
||||
struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
|
||||
|
||||
if (attr == &dev_attr_machine)
|
||||
return sprintf(buf, "%s\n", soc_dev->attr->machine);
|
||||
if (attr == &dev_attr_family)
|
||||
return sprintf(buf, "%s\n", soc_dev->attr->family);
|
||||
if (attr == &dev_attr_revision)
|
||||
return sprintf(buf, "%s\n", soc_dev->attr->revision);
|
||||
if (attr == &dev_attr_soc_id)
|
||||
return sprintf(buf, "%s\n", soc_dev->attr->soc_id);
|
||||
|
||||
return -EINVAL;
|
||||
|
||||
}
|
||||
|
||||
static struct attribute *soc_attr[] = {
|
||||
&dev_attr_machine.attr,
|
||||
&dev_attr_family.attr,
|
||||
&dev_attr_soc_id.attr,
|
||||
&dev_attr_revision.attr,
|
||||
NULL,
|
||||
};
|
||||
|
||||
static const struct attribute_group soc_attr_group = {
|
||||
.attrs = soc_attr,
|
||||
.is_visible = soc_attribute_mode,
|
||||
};
|
||||
|
||||
static const struct attribute_group *soc_attr_groups[] = {
|
||||
&soc_attr_group,
|
||||
NULL,
|
||||
};
|
||||
|
||||
static void soc_release(struct device *dev)
|
||||
{
|
||||
struct soc_device *soc_dev = container_of(dev, struct soc_device, dev);
|
||||
|
||||
kfree(soc_dev);
|
||||
}
|
||||
|
||||
struct soc_device *soc_device_register(struct soc_device_attribute *soc_dev_attr)
|
||||
{
|
||||
struct soc_device *soc_dev;
|
||||
int ret;
|
||||
|
||||
soc_dev = kzalloc(sizeof(*soc_dev), GFP_KERNEL);
|
||||
if (!soc_dev) {
|
||||
ret = -ENOMEM;
|
||||
goto out1;
|
||||
}
|
||||
|
||||
/* Fetch a unique (reclaimable) SOC ID. */
|
||||
do {
|
||||
if (!ida_pre_get(&soc_ida, GFP_KERNEL)) {
|
||||
ret = -ENOMEM;
|
||||
goto out2;
|
||||
}
|
||||
|
||||
spin_lock(&soc_lock);
|
||||
ret = ida_get_new(&soc_ida, &soc_dev->soc_dev_num);
|
||||
spin_unlock(&soc_lock);
|
||||
|
||||
} while (ret == -EAGAIN);
|
||||
|
||||
if (ret)
|
||||
goto out2;
|
||||
|
||||
soc_dev->attr = soc_dev_attr;
|
||||
soc_dev->dev.bus = &soc_bus_type;
|
||||
soc_dev->dev.groups = soc_attr_groups;
|
||||
soc_dev->dev.release = soc_release;
|
||||
|
||||
dev_set_name(&soc_dev->dev, "soc%d", soc_dev->soc_dev_num);
|
||||
|
||||
ret = device_register(&soc_dev->dev);
|
||||
if (ret)
|
||||
goto out3;
|
||||
|
||||
return soc_dev;
|
||||
|
||||
out3:
|
||||
ida_remove(&soc_ida, soc_dev->soc_dev_num);
|
||||
out2:
|
||||
kfree(soc_dev);
|
||||
out1:
|
||||
return ERR_PTR(ret);
|
||||
}
|
||||
|
||||
/* Ensure soc_dev->attr is freed prior to calling soc_device_unregister. */
|
||||
void soc_device_unregister(struct soc_device *soc_dev)
|
||||
{
|
||||
ida_remove(&soc_ida, soc_dev->soc_dev_num);
|
||||
|
||||
device_unregister(&soc_dev->dev);
|
||||
}
|
||||
|
||||
static int __init soc_bus_register(void)
|
||||
{
|
||||
spin_lock_init(&soc_lock);
|
||||
|
||||
return bus_register(&soc_bus_type);
|
||||
}
|
||||
core_initcall(soc_bus_register);
|
||||
|
||||
static void __exit soc_bus_unregister(void)
|
||||
{
|
||||
ida_destroy(&soc_ida);
|
||||
|
||||
bus_unregister(&soc_bus_type);
|
||||
}
|
||||
module_exit(soc_bus_unregister);
|
||||
37
include/linux/sys_soc.h
Normal file
37
include/linux/sys_soc.h
Normal file
@ -0,0 +1,37 @@
|
||||
/*
|
||||
* Copyright (C) ST-Ericsson SA 2011
|
||||
* Author: Lee Jones <lee.jones@linaro.org> for ST-Ericsson.
|
||||
* License terms: GNU General Public License (GPL), version 2
|
||||
*/
|
||||
#ifndef __SOC_BUS_H
|
||||
#define __SOC_BUS_H
|
||||
|
||||
#include <linux/device.h>
|
||||
|
||||
struct soc_device_attribute {
|
||||
const char *machine;
|
||||
const char *family;
|
||||
const char *revision;
|
||||
const char *soc_id;
|
||||
};
|
||||
|
||||
/**
|
||||
* soc_device_register - register SoC as a device
|
||||
* @soc_plat_dev_attr: Attributes passed from platform to be attributed to a SoC
|
||||
*/
|
||||
struct soc_device *soc_device_register(
|
||||
struct soc_device_attribute *soc_plat_dev_attr);
|
||||
|
||||
/**
|
||||
* soc_device_unregister - unregister SoC device
|
||||
* @dev: SoC device to be unregistered
|
||||
*/
|
||||
void soc_device_unregister(struct soc_device *soc_dev);
|
||||
|
||||
/**
|
||||
* soc_device_to_device - helper function to fetch struct device
|
||||
* @soc: Previously registered SoC device container
|
||||
*/
|
||||
struct device *soc_device_to_device(struct soc_device *soc);
|
||||
|
||||
#endif /* __SOC_BUS_H */
|
||||
Loading…
Reference in New Issue
Block a user