From: Zhang Rui Date: Fri, 8 Dec 2006 09:23:43 +0000 (+0800) Subject: ACPI: use PNPID:instance_no as bus_id of ACPI device X-Git-Tag: v2.6.21-rc2~42^2~12^2^2~7^2~6 X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=e49bd2dd5a503bb94fe2f2af45422b610940b75d;p=linux-2.6-omap-h63xx.git ACPI: use PNPID:instance_no as bus_id of ACPI device Previously we used the device name in the DSDT, but would crash upon encountering a duplicate. Also, exposing the DSDT device name to the user in a patch isn't a good idea, because it is arbitrary. After some discussion, we finally decided to use "PNPID:instance_no" as the bus_id of ACPI devices. Two attributes for each device are added at the same time, the full pathname in ACPI namespace and hardware_id if it has. NOTE: acpi_bus_id_list is used to keep the information of PNPID and instance number of the given PNPID. Loop the acpi_bus_id_list to find the instance_no of the same PNPID when register a device. If failed, i.e. we don't have a node with this PNPID, allocate one and link it to this list. NOTE: Now I don't take the memory free work in charge. If necessary, I can add a reference count in struct acpi_device_bus_id, and check the reference and when unregister a device, i.e. memory is freed when the reference count of a given PNPID is 0. Signed-off-by: Li Shaohua Signed-off-by: Len Brown --- diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 9efe3e9dbf2..769e54bc922 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -21,9 +21,15 @@ extern struct acpi_device *acpi_root; #define ACPI_BUS_DEVICE_NAME "System Bus" static LIST_HEAD(acpi_device_list); +static LIST_HEAD(acpi_bus_id_list); DEFINE_SPINLOCK(acpi_device_lock); LIST_HEAD(acpi_wakeup_device_list); +struct acpi_device_bus_id{ + char bus_id[9]; + unsigned int instance_no; + struct list_head node; +}; static int acpi_eject_operation(acpi_handle handle, int lockable) { struct acpi_object_list arg_list; @@ -103,18 +109,61 @@ acpi_eject_store(struct device *d, struct device_attribute *attr, static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store); -static void acpi_device_setup_files(struct acpi_device *dev) +static ssize_t +acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) { + struct acpi_device *acpi_dev = to_acpi_device(dev); + + return sprintf(buf, "%s\n", acpi_dev->pnp.hardware_id); +} +static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL); + +static ssize_t +acpi_device_path_show(struct device *dev, struct device_attribute *attr, char *buf) { + struct acpi_device *acpi_dev = to_acpi_device(dev); + struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL}; + int result; + + result = acpi_get_name(acpi_dev->handle, ACPI_FULL_PATHNAME, &path); + if(result) + goto end; + + result = sprintf(buf, "%s\n", (char*)path.pointer); + kfree(path.pointer); + end: + return result; +} +static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL); + +static int acpi_device_setup_files(struct acpi_device *dev) { acpi_status status; acpi_handle temp; + int result = 0; /* - * If device has _EJ0, 'eject' file is created that is used to trigger - * hot-removal function from userland. + * Devices gotten from FADT don't have a "path" attribute */ + if(dev->handle) { + result = device_create_file(&dev->dev, &dev_attr_path); + if(result) + goto end; + } + + if(dev->flags.hardware_id) { + result = device_create_file(&dev->dev, &dev_attr_hid); + if(result) + goto end; + } + + /* + * If device has _EJ0, 'eject' file is created that is used to trigger + * hot-removal function from userland. + */ status = acpi_get_handle(dev->handle, "_EJ0", &temp); if (ACPI_SUCCESS(status)) - device_create_file(&dev->dev, &dev_attr_eject); + result = device_create_file(&dev->dev, &dev_attr_eject); + end: + return result; } static void acpi_device_remove_files(struct acpi_device *dev) @@ -129,6 +178,11 @@ static void acpi_device_remove_files(struct acpi_device *dev) status = acpi_get_handle(dev->handle, "_EJ0", &temp); if (ACPI_SUCCESS(status)) device_remove_file(&dev->dev, &dev_attr_eject); + + if(dev->flags.hardware_id) + device_remove_file(&dev->dev, &dev_attr_hid); + if(dev->handle) + device_remove_file(&dev->dev, &dev_attr_path); } /* -------------------------------------------------------------------------- ACPI Bus operations @@ -260,9 +314,12 @@ static struct bus_type acpi_bus_type = { .uevent = acpi_device_uevent, }; -static void acpi_device_register(struct acpi_device *device, +static int acpi_device_register(struct acpi_device *device, struct acpi_device *parent) { + int result; + struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id; + int found = 0; /* * Linkage * ------- @@ -273,7 +330,33 @@ static void acpi_device_register(struct acpi_device *device, INIT_LIST_HEAD(&device->g_list); INIT_LIST_HEAD(&device->wakeup_list); + new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL); + if (!new_bus_id) { + printk(KERN_ERR PREFIX "Memory allocation error\n"); + return -ENOMEM; + } + spin_lock(&acpi_device_lock); + /* + * Find suitable bus_id and instance number in acpi_bus_id_list + * If failed, create one and link it into acpi_bus_id_list + */ + list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) { + if(!strcmp(acpi_device_bus_id->bus_id, device->flags.hardware_id? device->pnp.hardware_id : "PNPIDNON")) { + acpi_device_bus_id->instance_no ++; + found = 1; + kfree(new_bus_id); + break; + } + } + if(!found) { + acpi_device_bus_id = new_bus_id; + strcpy(acpi_device_bus_id->bus_id, device->flags.hardware_id ? device->pnp.hardware_id : "PNPIDNON"); + acpi_device_bus_id->instance_no = 0; + list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list); + } + sprintf(device->dev.bus_id, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no); + if (device->parent) { list_add_tail(&device->node, &device->parent->children); list_add_tail(&device->g_list, &device->parent->g_list); @@ -287,12 +370,29 @@ static void acpi_device_register(struct acpi_device *device, device->dev.parent = &parent->dev; device->dev.bus = &acpi_bus_type; device_initialize(&device->dev); - sprintf(device->dev.bus_id, "%s", device->pnp.bus_id); device->dev.release = &acpi_device_release; - device_add(&device->dev); + result = device_add(&device->dev); + if(result) { + printk("Error adding device %s", device->dev.bus_id); + goto end; + } + + result = acpi_device_setup_files(device); + if(result) + ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Error creating sysfs interface for device %s\n", device->dev.bus_id)); - acpi_device_setup_files(device); device->removal_type = ACPI_BUS_REMOVAL_NORMAL; + return 0; + end: + spin_lock(&acpi_device_lock); + if (device->parent) { + list_del(&device->node); + list_del(&device->g_list); + } else + list_del(&device->g_list); + list_del(&device->wakeup_list); + spin_unlock(&acpi_device_lock); + return result; } static void acpi_device_unregister(struct acpi_device *device, int type) @@ -1035,7 +1135,7 @@ acpi_add_single_object(struct acpi_device **child, acpi_device_get_debug_info(device, handle, type); - acpi_device_register(device, parent); + result = acpi_device_register(device, parent); end: if (!result)