From aed1a4dd88e94001b811b297c1ff734c3f8d22d9 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sat, 25 Jul 2015 21:52:34 +0900 Subject: dm: add DM_FLAG_BOUND flag Currently, we only have DM_FLAG_ACTIVATED to indicate the device status, but we still cannot know in which stage is in progress, binding or probing. This commit introduces a new flag, DM_FLAG_BOUND, which is set when the device is really bound, and cleared when it is unbound. Signed-off-by: Masahiro Yamada Acked-by: Simon Glass --- drivers/core/device-remove.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/core/device-remove.c') diff --git a/drivers/core/device-remove.c b/drivers/core/device-remove.c index 6b87f865e40..45d6543067b 100644 --- a/drivers/core/device-remove.c +++ b/drivers/core/device-remove.c @@ -61,6 +61,9 @@ int device_unbind(struct udevice *dev) if (dev->flags & DM_FLAG_ACTIVATED) return -EINVAL; + if (!(dev->flags & DM_FLAG_BOUND)) + return -EINVAL; + drv = dev->driver; assert(drv); -- cgit v1.2.3 From 608f26c51bebc68db7f2edc7590ee513d2bc5465 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sat, 25 Jul 2015 21:52:35 +0900 Subject: devres: introduce Devres (Managed Device Resource) framework In U-Boot's driver model, memory is basically allocated and freed in the core framework. So, low level drivers generally only have to specify the size of needed memory with .priv_auto_alloc_size, .platdata_auto_alloc_size, etc. Nevertheless, some drivers still need to allocate/free memory on their own in case they cannot statically know the necessary memory size. So, I believe it is reasonable enough to port Devres into U-boot. Devres, which originates in Linux, manages device resources for each device and automatically releases them on driver detach. With devres, device resources are guaranteed to be freed whether initialization fails half-way or the device gets detached. The basic idea is totally the same to that of Linux, but I tweaked it a bit so that it fits in U-Boot's driver model. In U-Boot, drivers are activated in two steps: binding and probing. Binding puts a driver and a device together. It is just data manipulation on the system memory, so nothing has happened on the hardware device at this moment. When the device is really used, it is probed. Probing initializes the real hardware device to make it really ready for use. So, the resources acquired during the probing process must be freed when the device is removed. Likewise, what has been allocated in binding should be released when the device is unbound. The struct devres has a member "probe" to remember when the resource was allocated. CONFIG_DEBUG_DEVRES is also supported for easier debugging. If enabled, debug messages are printed each time a resource is allocated/freed. Signed-off-by: Masahiro Yamada Acked-by: Simon Glass --- drivers/core/device-remove.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/core/device-remove.c') diff --git a/drivers/core/device-remove.c b/drivers/core/device-remove.c index 45d6543067b..bd6d4062c93 100644 --- a/drivers/core/device-remove.c +++ b/drivers/core/device-remove.c @@ -95,6 +95,9 @@ int device_unbind(struct udevice *dev) if (dev->parent) list_del(&dev->sibling_node); + + devres_release_all(dev); + free(dev); return 0; @@ -128,6 +131,8 @@ void device_free(struct udevice *dev) dev->parent_priv = NULL; } } + + devres_release_probe(dev); } int device_remove(struct udevice *dev) -- cgit v1.2.3