On Sat, Jan 16, 2016 at 4:56 AM, Michał Kępień <kernel@xxxxxxxxxx> wrote:
>> WMI is logically a bus: the WMI driver binds to an ACPI node (or
>> more than one), and each instance of the WMI driver enumerates its
>> children and hopes that drivers will attach to the children that are
>> useful.
>>
>> This patch gives WMI a driver model bus type and the ability to
>> match to drivers. The bus itself is a device in the new "wmi_bus"
>> class, and all of the individual WMI devices are slotted into the
>> device hierarchy correctly.
>>
>> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
>> ---
>> drivers/platform/x86/wmi.c | 198 +++++++++++++++++++++++++++++++++++----------
>> include/linux/wmi.h | 47 +++++++++++
>> 2 files changed, 202 insertions(+), 43 deletions(-)
>> create mode 100644 include/linux/wmi.h
>>
>> diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
>> index dcb34a5f5669..2fa9493bd35c 100644
>> --- a/drivers/platform/x86/wmi.c
>> +++ b/drivers/platform/x86/wmi.c
>> @@ -37,14 +37,13 @@
>> #include <linux/acpi.h>
>> #include <linux/slab.h>
>> #include <linux/module.h>
>> +#include <linux/wmi.h>
>>
>> ACPI_MODULE_NAME("wmi");
>> MODULE_AUTHOR("Carlos Corbacho");
>> MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
>> MODULE_LICENSE("GPL");
>>
>> -#define ACPI_WMI_CLASS "wmi"
>> -
>> static LIST_HEAD(wmi_block_list);
>>
>> struct guid_block {
>> @@ -61,12 +60,12 @@ struct guid_block {
>> };
>>
>> struct wmi_block {
>> + struct wmi_device dev;
>> struct list_head list;
>> struct guid_block gblock;
>> struct acpi_device *acpi_device;
>> wmi_notify_handler handler;
>> void *handler_data;
>> - struct device dev;
>> };
>>
>>
>> @@ -101,8 +100,8 @@ static const struct acpi_device_id wmi_device_ids[] = {
>> MODULE_DEVICE_TABLE(acpi, wmi_device_ids);
>>
>> static struct acpi_driver acpi_wmi_driver = {
>> - .name = "wmi",
>> - .class = ACPI_WMI_CLASS,
>> + .name = "acpi-wmi",
>> + .owner = THIS_MODULE,
>> .ids = wmi_device_ids,
>> .ops = {
>> .add = acpi_wmi_add,
>> @@ -623,77 +622,146 @@ bool wmi_has_guid(const char *guid_string)
>> }
>> EXPORT_SYMBOL_GPL(wmi_has_guid);
>>
>> +static struct wmi_block *dev_to_wblock(struct device *dev)
>> +{
>> + return container_of(dev, struct wmi_block, dev.dev);
>> +}
>> +
>> +static struct wmi_device *dev_to_wdev(struct device *dev)
>> +{
>> + return container_of(dev, struct wmi_device, dev);
>> +}
>> +
>> /*
>> * sysfs interface
>> */
>> static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
>> char *buf)
>> {
>> - struct wmi_block *wblock;
>> -
>> - wblock = dev_get_drvdata(dev);
>> - if (!wblock) {
>> - strcat(buf, "\n");
>> - return strlen(buf);
>> - }
>> + struct wmi_block *wblock = dev_to_wblock(dev);
>>
>> return sprintf(buf, "wmi:%pUL\n", wblock->gblock.guid);
>> }
>> static DEVICE_ATTR_RO(modalias);
>>
>> +static ssize_t guid_show(struct device *dev, struct device_attribute *attr,
>> + char *buf)
>> +{
>> + struct wmi_block *wblock = dev_to_wblock(dev);
>> +
>> + return sprintf(buf, "%pUL\n", wblock->gblock.guid);
>> +}
>> +static DEVICE_ATTR_RO(guid);
>> +
>> static struct attribute *wmi_attrs[] = {
>> &dev_attr_modalias.attr,
>> + &dev_attr_guid.attr,
>> NULL,
>> };
>> ATTRIBUTE_GROUPS(wmi);
>>
>> static int wmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
>> {
>> - char guid_string[37];
>> -
>> - struct wmi_block *wblock;
>> + struct wmi_block *wblock = dev_to_wblock(dev);
>>
>> - if (add_uevent_var(env, "MODALIAS="))
>> + if (add_uevent_var(env, "MODALIAS=wmi:%pUL", wblock->gblock.guid))
>> return -ENOMEM;
>>
>> - wblock = dev_get_drvdata(dev);
>> - if (!wblock)
>> + if (add_uevent_var(env, "WMI_GUID=%pUL", wblock->gblock.guid))
>> return -ENOMEM;
>>
>> - sprintf(guid_string, "%pUL", wblock->gblock.guid);
>> + return 0;
>> +}
>> +
>> +static void wmi_dev_release(struct device *dev)
>> +{
>> + struct wmi_block *wblock = dev_to_wblock(dev);
>> +
>> + kfree(wblock);
>> +}
>> +
>> +static int wmi_dev_match(struct device *dev, struct device_driver *driver)
>> +{
>> + struct wmi_driver *wmi_driver =
>> + container_of(driver, struct wmi_driver, driver);
>> + struct wmi_block *wblock = dev_to_wblock(dev);
>> + const struct wmi_device_id *id = wmi_driver->id_table;
>>
>> - strcpy(&env->buf[env->buflen - 1], "wmi:");
>> - memcpy(&env->buf[env->buflen - 1 + 4], guid_string, 36);
>> - env->buflen += 40;
>> + while (id->guid_string) {
>> + u8 tmp[16], driver_guid[16];
>> +
>> + wmi_parse_guid(id->guid_string, tmp);
>> + wmi_swap_bytes(tmp, driver_guid);
>> + if (!memcmp(driver_guid, wblock->gblock.guid, 16))
>> + return 1;
>> +
>> + id++;
>> + }
>>
>> return 0;
>> }
>>
>> -static void wmi_dev_free(struct device *dev)
>> +int wmi_dev_probe(struct device *dev)
>
> Can be static.
Indeed, thanks.
>
>> {
>> - struct wmi_block *wmi_block = container_of(dev, struct wmi_block, dev);
>> + struct wmi_block *wblock = dev_to_wblock(dev);
>> + struct wmi_driver *wdriver =
>> + container_of(dev->driver, struct wmi_driver, driver);
>> + int ret = 0;
>> +
>> + if (ACPI_FAILURE(wmi_method_enable(wblock, 1)))
>> + dev_warn(dev, "failed to enable device -- probing anyway\n");
>> +
>> + if (wdriver->probe) {
>> + ret = wdriver->probe(dev_to_wdev(dev));
>> + if (ret != 0 && ACPI_FAILURE(wmi_method_enable(wblock, 0)))
>> + dev_warn(dev, "failed to disable device\n");
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +int wmi_dev_remove(struct device *dev)
>
> Can be static.
Fixed.
>
>> +{
>> + struct wmi_block *wblock = dev_to_wblock(dev);
>> + struct wmi_driver *wdriver =
>> + container_of(dev->driver, struct wmi_driver, driver);
>> + int ret = 0;
>> +
>> + if (wdriver->remove)
>> + ret = wdriver->remove(dev_to_wdev(dev));
>> +
>> + if (ACPI_FAILURE(wmi_method_enable(wblock, 0)))
>> + dev_warn(dev, "failed to disable device\n");
>>
>> - kfree(wmi_block);
>> + return ret;
>> }
>>
>> -static struct class wmi_class = {
>> +static struct class wmi_bus_class = {
>> + .name = "wmi_bus",
>> +};
>> +
>> +static struct bus_type wmi_bus_type = {
>> .name = "wmi",
>> - .dev_release = wmi_dev_free,
>> - .dev_uevent = wmi_dev_uevent,
>> .dev_groups = wmi_groups,
>> + .match = wmi_dev_match,
>> + .uevent = wmi_dev_uevent,
>> + .probe = wmi_dev_probe,
>> + .remove = wmi_dev_remove,
>> };
>>
>> -static int wmi_create_device(const struct guid_block *gblock,
>> +static int wmi_create_device(struct device *wmi_bus_dev,
>> + const struct guid_block *gblock,
>> struct wmi_block *wblock,
>> struct acpi_device *device)
>> {
>> - wblock->dev.class = &wmi_class;
>> + wblock->dev.dev.bus = &wmi_bus_type;
>> + wblock->dev.dev.parent = wmi_bus_dev;
>>
>> - dev_set_name(&wblock->dev, "%pUL", gblock->guid);
>> + dev_set_name(&wblock->dev.dev, "%pUL", gblock->guid);
>>
>> - dev_set_drvdata(&wblock->dev, wblock);
>> + wblock->dev.dev.release = wmi_dev_release;
>>
>> - return device_register(&wblock->dev);
>> + return device_register(&wblock->dev.dev);
>> }
>>
>> static void wmi_free_devices(struct acpi_device *device)
>> @@ -704,8 +772,8 @@ static void wmi_free_devices(struct acpi_device *device)
>> list_for_each_entry_safe(wblock, next, &wmi_block_list, list) {
>> if (wblock->acpi_device == device) {
>> list_del(&wblock->list);
>> - if (wblock->dev.class)
>> - device_unregister(&wblock->dev);
>> + if (wblock->dev.dev.bus)
>> + device_unregister(&wblock->dev.dev);
>> else
>> kfree(wblock);
>> }
>> @@ -737,7 +805,7 @@ static bool guid_already_parsed(struct acpi_device *device,
>> /*
>> * Parse the _WDG method for the GUID data blocks
>> */
>> -static int parse_wdg(struct acpi_device *device)
>> +static int parse_wdg(struct device *wmi_bus_dev, struct acpi_device *device)
>> {
>> struct acpi_buffer out = {ACPI_ALLOCATE_BUFFER, NULL};
>> union acpi_object *obj;
>> @@ -781,7 +849,8 @@ static int parse_wdg(struct acpi_device *device)
>> for device creation.
>> */
>> if (!guid_already_parsed(device, gblock[i].guid)) {
>> - retval = wmi_create_device(&gblock[i], wblock, device);
>> + retval = wmi_create_device(wmi_bus_dev, &gblock[i],
>> + wblock, device);
>> if (retval) {
>> wmi_free_devices(device);
>> goto out_free_pointer;
>> @@ -881,12 +950,15 @@ static int acpi_wmi_remove(struct acpi_device *device)
>> acpi_remove_address_space_handler(device->handle,
>> ACPI_ADR_SPACE_EC, &acpi_wmi_ec_space_handler);
>> wmi_free_devices(device);
>> + device_unregister((struct device *)acpi_driver_data(device));
>> + device->driver_data = NULL;
>>
>> return 0;
>> }
>>
>> static int acpi_wmi_add(struct acpi_device *device)
>> {
>> + struct device *wmi_bus_dev;
>> acpi_status status;
>> int error;
>>
>> @@ -899,14 +971,26 @@ static int acpi_wmi_add(struct acpi_device *device)
>> return -ENODEV;
>> }
>>
>> - error = parse_wdg(device);
>> + wmi_bus_dev = device_create(&wmi_bus_class, &device->dev, MKDEV(0, 0),
>> + NULL, "wmi_bus-%s", dev_name(&device->dev));
>> + if (IS_ERR(wmi_bus_dev)) {
>> + error = PTR_ERR(wmi_bus_dev);
>> + goto err_remove_handler;
>> + }
>> + device->driver_data = wmi_bus_dev;
>> +
>> + error = parse_wdg(wmi_bus_dev, device);
>> if (error) {
>> pr_err("Failed to parse WDG method\n");
>> - goto err_remove_handler;
>> + goto err_remove_busdev;
>> }
>>
>> return 0;
>>
>> +err_remove_busdev:
>> + device_unregister(wmi_bus_dev);
>> + put_device(wmi_bus_dev);
>
> I believe this put_device() call is excessive. device_create() calls
> device_initialize() and device_add(); device_unregister() calls
> device_del() and put_device(), so it should already take care of
> removing all references to wmi_bus_dev. Am I missing something?
>
I think you're right, and my acpi_wmi_remove agrees.
--Andy
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