This patch implements sysfs interfaces to access system device hotplug
functionalities. These sysfs interfaces are mainly used to drive the
hotplug slot state machine as below:
[ABSENT] <-> [PRESENT] <-> [POWERED] <-> [CONNECTED] <-> [CONFIGURED]
[ABSENT]: no devices attached to the hotplug slot
[PRESENT]: devices physically attached to the hotplug slot
[POWERED]: devices attached to the hotplug slot are powered
[CONNECTED]: ACPI device objects have been created for devices attached
to the hotplug slot
[CONFIGURED]: devices attached to the slot are in use by system
Two sysfs interfaces have been implemented as below:
SLOT/dependency: show dependency relationship among hotplug slots
SLOT/control: trigger system device hotplug operations
read from control sysfs file gives some help messages and you may
write following commands to it:
poweron: transit to POWERED from PRESENT
connect: transit to CONNECTED from PRESENT/POWERED
configure: transit to CONFIGURED from PRESENT/POWERED/CONNECTED
unconfigure: transit to CONNECTED from CONFIGURED
disconnect: transit to POWERED from CONFIGURED/CONNECTED
poweroff: transit PRESENT from CONFIGURED/CONNECTED/POWERED
enable, 1: the same as configure
disable, 0: the same as poweroff
cancel: cancel inprogress hotplug operations
Signed-off-by: Jiang Liu <jiang....@huawei.com>
Signed-off-by: Hanjun Guo <guohan...@huawei.com>
---
drivers/acpi/hotplug/Makefile | 1 +
drivers/acpi/hotplug/acpihp_drv.h | 3 +
drivers/acpi/hotplug/drv_main.c | 5 +
drivers/acpi/hotplug/sysfs.c | 181 +++++++++++++++++++++++++++++++++++++
4 files changed, 190 insertions(+)
create mode 100644 drivers/acpi/hotplug/sysfs.c
diff --git a/drivers/acpi/hotplug/Makefile b/drivers/acpi/hotplug/Makefile
index 0f43933..57e348a 100644
--- a/drivers/acpi/hotplug/Makefile
+++ b/drivers/acpi/hotplug/Makefile
@@ -16,3 +16,4 @@ acpihp_drv-y += dependency.o
acpihp_drv-y += cancel.o
acpihp_drv-y += configure.o
acpihp_drv-y += state_machine.o
+acpihp_drv-y += sysfs.o
diff --git a/drivers/acpi/hotplug/acpihp_drv.h
b/drivers/acpi/hotplug/acpihp_drv.h
index 175ef81..2ec2547 100644
--- a/drivers/acpi/hotplug/acpihp_drv.h
+++ b/drivers/acpi/hotplug/acpihp_drv.h
@@ -92,4 +92,7 @@ int acpihp_drv_unconfigure(struct list_head *list);
/* The heart of the ACPI system device hotplug driver */
int acpihp_drv_change_state(struct acpihp_slot *slot, enum acpihp_drv_cmd cmd);
+int acpihp_drv_create_sysfs(struct acpihp_slot *slot);
+void acpihp_drv_remove_sysfs(struct acpihp_slot *slot);
+
#endif /* __ACPIHP_DRV_H__ */
diff --git a/drivers/acpi/hotplug/drv_main.c b/drivers/acpi/hotplug/drv_main.c
index 5a919e7..bd5c97c 100644
--- a/drivers/acpi/hotplug/drv_main.c
+++ b/drivers/acpi/hotplug/drv_main.c
@@ -284,6 +284,10 @@ static int acpihp_drv_slot_add(struct device *dev, struct
class_interface *intf)
return -ENOMEM;
}
+ if (acpihp_drv_create_sysfs(slot))
+ ACPIHP_SLOT_DEBUG(slot,
+ "fails to create sysfs interfaces, some functions will
not be available to user.\n");
+
return 0;
}
@@ -294,6 +298,7 @@ static void acpihp_drv_intf_remove(struct device *dev,
struct acpihp_slot *slot =
container_of(dev, struct acpihp_slot, dev);
+ acpihp_drv_remove_sysfs(slot);
acpihp_drv_uninstall_handler(slot);
acpihp_drv_remove_devices(slot);
acpihp_slot_detach_drv_data(slot, intf, (void **)&drv_data);
diff --git a/drivers/acpi/hotplug/sysfs.c b/drivers/acpi/hotplug/sysfs.c
new file mode 100644
index 0000000..4519eea
--- /dev/null
+++ b/drivers/acpi/hotplug/sysfs.c
@@ -0,0 +1,181 @@
+/*
+ * Copyright (C) 2012 Huawei Tech. Co., Ltd.
+ * Copyright (C) 2012 Jiang Liu <jiang....@huawei.com>
+ * Copyright (C) 2012 Hanjun Guo <guohan...@huawei.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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/device.h>
+#include <linux/mutex.h>
+#include <acpi/acpi_hotplug.h>
+#include "acpihp_drv.h"
+
+static ssize_t acpihp_drv_control_show(struct device *dev,
+ struct device_attribute *attr, char *page)
+{
+ ssize_t off;
+ struct acpihp_slot *slot = container_of(dev, struct acpihp_slot, dev);
+
+ off = snprintf(page, PAGE_SIZE, "supported commands:\n");
+ if (slot->capabilities & ACPIHP_SLOT_CAP_POWERON)
+ off += snprintf(page + off, PAGE_SIZE - off,
+ "\tpoweron: power on the hotplug slot\n");
+ off += snprintf(page + off, PAGE_SIZE - off,
+ "\tconnect: create ACPI device nodes and bind ACPI
device drivers\n");
+ off += snprintf(page + off, PAGE_SIZE - off,
+ "\tconfigure: put system devices into running state\n");
+ off += snprintf(page + off, PAGE_SIZE - off,
+ "\tunconfigure: stop system devices from running
state\n");
+ off += snprintf(page + off, PAGE_SIZE - off,
+ "\tdisconnect: unbind ACPI device drivers and destroy
ACPI device nodes\n");
+ if (slot->capabilities & ACPIHP_SLOT_CAP_POWEROFF)
+ off += snprintf(page + off, PAGE_SIZE - off,
+ "\tpoweroff: power off the hotplug slot\n");
+ off += snprintf(page + off, PAGE_SIZE - off,
+ "\tcancel: cancel inprogress hotplug operations\n");
+ off += snprintf(page + off, PAGE_SIZE - off,
+ "\tenable, 1: the same as configure\n");
+ off += snprintf(page + off, PAGE_SIZE - off,
+ "\tdisable, 0: the same as poweroff\n");
+
+ return off;
+}
+
+static ssize_t acpihp_drv_control_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ int result = -EINVAL;
+ char *temp, *pos, *token;
+ enum acpihp_drv_cmd cmd = ACPIHP_DRV_CMD_NOOP;
+ struct acpihp_slot *slot = container_of(dev, struct acpihp_slot, dev);
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ temp = pos = kstrndup(buf, PAGE_SIZE - 1, GFP_KERNEL);
+ if (!temp)
+ return -ENOMEM;
+
+ token = strsep(&pos, " \t\r\n");
+ if (!token)
+ goto out;
+
+ if (!strcmp(token, "enable"))
+ cmd = ACPIHP_DRV_CMD_CONFIGURE;
+ else if (!strcmp(token, "1"))
+ cmd = ACPIHP_DRV_CMD_CONFIGURE;
+ else if (!strcmp(token, "disable"))
+ cmd = ACPIHP_DRV_CMD_POWEROFF;
+ else if (!strcmp(token, "0"))
+ cmd = ACPIHP_DRV_CMD_POWEROFF;
+ else if (!strcmp(token, "connect"))
+ cmd = ACPIHP_DRV_CMD_CONNECT;
+ else if (!strcmp(token, "configure"))
+ cmd = ACPIHP_DRV_CMD_CONFIGURE;
+ else if (!strcmp(token, "unconfigure"))
+ cmd = ACPIHP_DRV_CMD_UNCONFIGURE;
+ else if (!strcmp(token, "disconnect"))
+ cmd = ACPIHP_DRV_CMD_DISCONNECT;
+ else if (!strcmp(token, "cancel"))
+ cmd = ACPIHP_DRV_CMD_CANCEL;
+ else if (!strcmp(token, "poweron")) {
+ if (slot->capabilities & ACPIHP_SLOT_CAP_POWERON)
+ cmd = ACPIHP_DRV_CMD_POWERON;
+ } else if (!strcmp(token, "poweroff")) {
+ if (slot->capabilities & ACPIHP_SLOT_CAP_POWEROFF)
+ cmd = ACPIHP_DRV_CMD_POWEROFF;
+ }
+
+ if (cmd != ACPIHP_DRV_CMD_NOOP)
+ result = acpihp_drv_change_state(slot, cmd);
+out:
+ kfree(temp);
+
+ return result < 0 ? result : count;
+}
+
+static DEVICE_ATTR(control, S_IRUGO | S_IWUSR,
+ &acpihp_drv_control_show, &acpihp_drv_control_store);
+
+static ssize_t acpihp_drv_dependency_show(struct device *dev,
+ struct device_attribute *attr, char *page)
+{
+ int ret;
+ char *p, *end;
+ struct list_head list;
+ enum acpihp_drv_cmd cmd;
+ struct acpihp_slot_dependency *dep;
+ struct acpihp_slot *slot = container_of(dev, struct acpihp_slot, dev);
+
+ INIT_LIST_HEAD(&list);
+ mutex_lock(&state_machine_mutex);
+ cmd = acpihp_slot_powered(slot) ? ACPIHP_DRV_CMD_POWEROFF :
+ ACPIHP_DRV_CMD_POWERON;
+ ret = acpihp_drv_generate_dependency_list(slot, &list, cmd);
+ if (ret) {
+ ret = -ENXIO;
+ } else {
+ p = page;
+ end = page + PAGE_SIZE;
+
+ list_for_each_entry(dep, &list, node) {
+ if (dep->slot == slot)
+ continue;
+ if (p + strlen(dep->slot->name) + 2 >= end)
+ break;
+ p += snprintf(p, end - p, "%s\n", dep->slot->name);
+ }
+
+ acpihp_drv_destroy_dependency_list(&list);
+ ret = p - page;
+ }
+ mutex_unlock(&state_machine_mutex);
+
+ return ret;
+}
+
+static DEVICE_ATTR(dependency, S_IRUGO,
+ &acpihp_drv_dependency_show, NULL);
+
+int acpihp_drv_create_sysfs(struct acpihp_slot *slot)
+{
+ int retval;
+ struct device *dev = &slot->dev;
+
+ retval = device_create_file(dev, &dev_attr_control);
+ if (retval)
+ goto out;
+ retval = device_create_file(dev, &dev_attr_dependency);
+ if (!retval)
+ return 0;
+
+ device_remove_file(dev, &dev_attr_control);
+out:
+ ACPIHP_SLOT_DEBUG(slot, "fails to create sysfs interfaces for slot.\n");
+ return retval;
+}
+
+void acpihp_drv_remove_sysfs(struct acpihp_slot *slot)
+{
+ struct device *dev = &slot->dev;
+
+ device_remove_file(dev, &dev_attr_dependency);
+ device_remove_file(dev, &dev_attr_control);
+}
--
1.7.9.5
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