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 <yamada.masahiro@socionext.com>
Acked-by: Simon Glass <sjg@chromium.org>
Not all boards use garbage collection in their link step, so we should avoid
adding options that rely on this for prevention of code bloat. Add separate
Kconfig options for syscon and regmap uclasses.
Signed-off-by: Simon Glass <sjg@chromium.org>
As you see in driver/Makefile, Kbuild descends into the driver/core/
directory only when CONFIG_DM is enabled.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Simon Glass <sjg@chromium.org>
Many SoCs have a number of system controllers which are dealt with as a
group by a single driver. It is a pain to have to add lots of compatible
strings and/or separate drivers for each. Instead we can identify the
controllers by a number and request the address of the one we want.
Add a simple implementation of this which can be used by SoC driver code.
Signed-off-by: Simon Glass <sjg@chromium.org>
Add a simple implementaton of register maps, supporting only direct I/O
for now. This can be enhanced later to support buses which have registers,
such as I2C, SPI and PCI.
It allows drivers which can operate with multiple buses to avoid dealing
with the particulars of register access on that bus.
Signed-off-by: Simon Glass <sjg@chromium.org>
In SPL it is sometimes useful to be able to obtain a dump of the current
driver model state. Since commands are not available, provide a way to
directly call the functions to output this information.
Adjust the existing commands to use these functions.
Signed-off-by: Simon Glass <sjg@chromium.org>
Allow SPL to be built with this option so that we can support device tree
control. Disable the simple bus for now in SPL. It may be needed later.
Signed-off-by: Simon Glass <sjg@chromium.org>
For SPL we don't expect to need to remove a device. Save some code space
by dropping this feature. The board config can define
CONFIG_DM_DEVICE_REMOVE if this is in fact needed.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@ti.com>
[1] Move driver/core/, driver/input/ and drivers/input/ entries
from the top Makefile to drivers/Makefile
[2] Remove the conditional by CONFIG_DM in drivers/core/Makefile
because the whole drivers/core directory is already selected
by CONFIG_DM in the upper level
[3] Likewise for CONFIG_DM_DEMO in drivers/demo/Makefile
[4] Simplify common/Makefile - both CONFIG_DDR_SPD and
CONFIG_SPD_EEPROM are boolean macros so they can directly
select objects
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Marek Vasut <marex@denx.de>
Add driver model functionality for generic board.
This includes data structures and base code for registering devices and
uclasses (groups of devices with the same purpose, e.g. all I2C ports will
be in the same uclass).
The feature is enabled with CONFIG_DM.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Pavel Herrmann <morpheus.ibis@gmail.com>
Signed-off-by: Viktor Křivák <viktor.krivak@gmail.com>
Signed-off-by: Tomas Hlavacek <tmshlvck@gmail.com>
