This patch adds support for a new struct device member "assets" which may point to an array of struct assets.
The array is terminated by one with a NULL pre_probe callback. These assets consist of named (in .name) or anonymous object pointers (.data) operated on by specified callbacks. A void * is provided to give configuration data or pointer if needed. Before device probe, any assets associated with the device have their pre_probe() callback called, which will typically "enable" them, and after device removal the post_remove() callback is called which will typically disable them. Signed-off-by: Andy Green <[email protected]> --- drivers/base/dd.c | 36 ++++++++++++++++++++++++++++++++++++ include/linux/device.h | 25 +++++++++++++++++++++++++ 2 files changed, 61 insertions(+) diff --git a/drivers/base/dd.c b/drivers/base/dd.c index e3bbed8..d37210a 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -261,6 +261,7 @@ static DECLARE_WAIT_QUEUE_HEAD(probe_waitqueue); static int really_probe(struct device *dev, struct device_driver *drv) { + struct device_asset *asset; int ret = 0; atomic_inc(&probe_count); @@ -275,6 +276,23 @@ static int really_probe(struct device *dev, struct device_driver *drv) goto probe_failed; } + asset = dev->assets; + while (asset && asset->pre_probe) { + dev_info(dev, "Enabling pre-probe asset %s\n", asset->name); + ret = asset->pre_probe(dev, asset); + if (ret) { + dev_err(dev, "Error Enabling pre-probe asset %s\n", + asset->name); + if (asset != dev->assets) + do { + asset--; + asset->post_remove(dev, asset); + } while (asset != dev->assets); + goto probe_failed; + } + asset++; + } + if (dev->bus->probe) { ret = dev->bus->probe(dev); if (ret) @@ -478,6 +496,7 @@ EXPORT_SYMBOL_GPL(driver_attach); static void __device_release_driver(struct device *dev) { struct device_driver *drv; + struct device_asset *asset; drv = dev->driver; if (drv) { @@ -496,6 +515,23 @@ static void __device_release_driver(struct device *dev) dev->bus->remove(dev); else if (drv->remove) drv->remove(dev); + + asset = dev->assets; + if (asset) { + /* remove in reverse order */ + while (asset->pre_probe) + asset++; + + if (asset != dev->assets) + do { + asset--; + dev_info(dev, + "Disabling post-remove asset %s\n", + asset->name); + asset->post_remove(dev, asset); + } while (asset != dev->assets); + } + devres_release_all(dev); dev->driver = NULL; dev_set_drvdata(dev, NULL); diff --git a/include/linux/device.h b/include/linux/device.h index 86ef6ab..6eabe1d 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -577,6 +577,26 @@ struct device_dma_parameters { }; /** + * struct device_asset - a prerequisite for this device's probing + * @name: Name of the regulator, clock, etc. Optional. + * @asset: Pointer to the regulator, clock, etc. If no name is given, + * this can be set before device probe, otherwise the pre_probe + * handler will dereference the name and store a pointer here + * @data: Optional configuration data the asset may need + * @pre_probe: Called before this device this is associated with gets + * probed. + * @post_remove: Called after this device instance gets removed. + */ + +struct device_asset { + const char *name; + void *asset; + void *data; + int (*pre_probe)(struct device *device, struct device_asset *asset); + void (*post_remove)(struct device *device, struct device_asset *asset); +}; + +/** * struct device - The basic device structure * @parent: The device's "parent" device, the device to which it is attached. * In most cases, a parent device is some sort of bus or host @@ -600,6 +620,9 @@ struct device_dma_parameters { * variants, which GPIO pins act in what additional roles, and so * on. This shrinks the "Board Support Packages" (BSPs) and * minimizes board-specific #ifdefs in drivers. + * @assets: Pointer to a NULL-pre_probe terminated array of named or + * pointed-to objects that should be enabled for this device + * just before probe and disabled after removal * @power: For device power management. * See Documentation/power/devices.txt for details. * @pm_domain: Provide callbacks that are executed during system suspend, @@ -653,6 +676,8 @@ struct device { device */ void *platform_data; /* Platform specific data, device core doesn't touch it */ + struct device_asset *assets; /* optional assets enabled before probe + * and disabled after removal */ struct dev_pm_info power; struct dev_pm_domain *pm_domain; -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
