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Subject[RFC PATCH 2/6] ACPI: Reference devices in ACPI Power Resource
Date
From: Zhang Rui <rui.zhang@intel.com>

ACPI Power Resource can power on/off a couple of devices.
Introduce interfaces to register/unregister a device to/from
an ACPI Power Resource.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
---
drivers/acpi/power.c | 128 +++++++++++++++++++++++++++++++++++++++++++++++
include/acpi/acpi_bus.h | 2 +
2 files changed, 130 insertions(+), 0 deletions(-)

diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
index 0d681fb..a7e2305 100644
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -84,10 +84,25 @@ struct acpi_power_resource {
u32 order;
unsigned int ref_count;
struct mutex resource_lock;
+ struct list_head devices; /* list for devices powered by this PR */
};

static struct list_head acpi_power_resource_list;

+/*
+ * When a power resource is turned on, all the devices are put to an uninitialized
+ * state although their ACPI states are still D0.
+ * To handle this, we need to keep a list of all devices powered by the power resource,
+ * and resume all of them.
+ * Currently, we only support this case:
+ * 1) multiple devices share the same power resoruce,
+ * 2) One device uses One Power Resource ONLY.
+ */
+struct acpi_powered_device {
+ struct list_head node;
+ struct device *dev;
+};
+
/* --------------------------------------------------------------------------
Power Resource Management
-------------------------------------------------------------------------- */
@@ -455,6 +470,118 @@ int acpi_disable_wakeup_device_power(struct acpi_device *dev)
Device Power Management
-------------------------------------------------------------------------- */

+int acpi_power_resource_register_device(struct device *dev, acpi_handle handle)
+{
+ struct acpi_power_resource *resource;
+ struct acpi_device *acpi_dev, *res_dev;
+ acpi_handle res_handle = NULL;
+ struct acpi_powered_device *apd;
+ int i;
+ int ret;
+
+ if (!handle || !dev)
+ return -EINVAL;
+
+ ret = acpi_bus_get_device(handle, &acpi_dev);
+ if (ret)
+ goto no_power_resource;
+
+ if (!acpi_dev->power.flags.power_resources)
+ goto no_power_resource;
+
+ for (i = 0; i <= ACPI_STATE_D3; i++) {
+ struct acpi_device_power_state *ps = &acpi_dev->power.states[i];
+
+ if (!ps->flags.valid)
+ continue;
+
+ if (ps->resources.count > 1)
+ return 0;
+
+ if (!res_handle)
+ res_handle = ps->resources.handles[0];
+ else if (res_handle != ps->resources.handles[0])
+ return 0;
+ }
+
+ ret = acpi_bus_get_device(res_handle, &res_dev);
+ if (ret)
+ goto no_power_resource;
+
+ resource = res_dev->driver_data;
+ if (!resource)
+ goto no_power_resource;
+
+ apd = kzalloc(sizeof(struct acpi_powered_device), GFP_KERNEL);
+ if (!apd)
+ return -ENOMEM;
+
+ apd->dev = dev;
+ mutex_lock(&resource->resource_lock);
+ list_add_tail(&apd->node, &resource->devices);
+ mutex_unlock(&resource->resource_lock);
+ printk(KERN_INFO PREFIX "Device %s uses Power Resource %s\n", dev->kobj.name, acpi_device_name(res_dev));
+
+ return 0;
+
+no_power_resource:
+ printk(KERN_WARNING PREFIX "Invalid Power Resource to register!");
+ return -ENODEV;
+}
+
+void acpi_power_resource_unregister_device(struct device *dev, acpi_handle handle)
+{
+ struct acpi_power_resource *resource;
+ struct acpi_device *acpi_dev, *res_dev;
+ acpi_handle res_handle = NULL;
+ struct acpi_powered_device *apd, *tmp;
+ int i;
+ int ret;
+
+ if (!handle || !dev)
+ return;
+
+ ret = acpi_bus_get_device(handle, &acpi_dev);
+ if (ret)
+ return;
+
+ if (!acpi_dev->power.flags.power_resources)
+ return;
+
+ for (i = 0; i <= ACPI_STATE_D3; i++) {
+ struct acpi_device_power_state *ps = &acpi_dev->power.states[i];
+
+ if (!ps->flags.valid)
+ continue;
+
+ if (ps->resources.count > 1)
+ return;
+
+ res_handle = ps->resources.handles[0];
+ break;
+ }
+
+ if (!res_handle)
+ return;
+
+ ret = acpi_bus_get_device(res_handle, &res_dev);
+ if (ret)
+ return;
+
+ resource = res_dev->driver_data;
+ if (!resource)
+ return;
+
+ mutex_lock(&resource->resource_lock);
+ list_for_each_entry_safe(apd, tmp, &resource->devices, node) {
+ if (apd->dev == dev) {
+ list_del(&apd->node);
+ kfree(apd);
+ }
+ }
+ mutex_unlock(&resource->resource_lock);
+}
+
int acpi_power_get_inferred_state(struct acpi_device *device, int *state)
{
int result = 0;
@@ -550,6 +677,7 @@ static int acpi_power_add(struct acpi_device *device)

resource->device = device;
mutex_init(&resource->resource_lock);
+ INIT_LIST_HEAD(&resource->devices);
strcpy(resource->name, device->pnp.bus_id);
strcpy(acpi_device_name(device), ACPI_POWER_DEVICE_NAME);
strcpy(acpi_device_class(device), ACPI_POWER_CLASS);
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 6cd5b64..32fb899 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -322,6 +322,8 @@ int acpi_bus_get_status(struct acpi_device *device);
int acpi_bus_set_power(acpi_handle handle, int state);
int acpi_bus_update_power(acpi_handle handle, int *state_p);
bool acpi_bus_power_manageable(acpi_handle handle);
+int acpi_power_resource_register_device(struct device *dev, acpi_handle handle);
+void acpi_power_resource_unregister_device(struct device *dev, acpi_handle handle);
bool acpi_bus_can_wakeup(acpi_handle handle);
#ifdef CONFIG_ACPI_PROC_EVENT
int acpi_bus_generate_proc_event(struct acpi_device *device, u8 type, int data);
--
1.7.2.5


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