Buses sometimes want to pass data to their children when they are probed.
For example, a SPI bus may want to tell the slave device about the chip
select it is connected to.
Add a new function to permit the parent data to be supplied to the child.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
Buses need to iterate through their children in some situations. Add a few
functions to make this easy.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
The driver model supports two ways for passing device parameters;
Device Tree and platform_data (board file).
Each driver should generally support both of them because some
popular IPs are used on various platforms.
Assume the following scenario:
- The driver Foo is used on SoC Bar and SoC Baz
- The SoC Bar uses Device Tree control (CONFIG_OF_CONTROL=y)
- The SoC Baz does not support Device Tree; uses a board file
In this situation, the device driver Foo should work with/without
the device tree control. The driver should have .of_match and
.ofdata_to_platdata members for SoC Bar, while they are meaningless
for SoC Baz; therefore those device-tree control code should go
inside #ifdef CONFIG_OF_CONTROL.
The driver code will be like this:
#ifdef CONFIG_OF_CONTROL
static const struct udevice_id foo_of_match = {
{ .compatible = "foo_driver" },
{},
}
static int foo_ofdata_to_platdata(struct udevice *dev)
{
...
}
#endif
U_BOOT_DRIVER(foo_driver) = {
...
.of_match = of_match_ptr(foo_of_match),
.ofdata_to_platdata = of_match_ptr(foo_ofdata_to_platdata),
...
}
This idea has been borrowed from Linux.
(In Linux, this macro is defined in include/linux/of.h)
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Simon Glass <sjg@chromium.org>
Some devices (particularly bus devices) must track their children, knowing
when a new child is added so that it can be set up for communication on the
bus.
Add a child_pre_probe() method to provide this feature, and a corresponding
child_post_remove() method.
Signed-off-by: Simon Glass <sjg@chromium.org>
Some device types can have child devices and want to store information
about them. For example a USB flash stick attached to a USB host
controller would likely use this space. The controller can hold
information about the USB state of each of its children.
The data is stored attached to the child device in the 'parent_priv'
member. It can be auto-allocated by dm when the child is probed. To
do this, add a per_child_auto_alloc_size value to the parent driver.
Signed-off-by: Simon Glass <sjg@chromium.org>
Devices can have childen that can be addressed by a simple index, the
sequence number or a device tree offset. Add functions to access a child
in each of these ways.
The index is typically used as a fallback when the sequence number is not
available. For example we may use a serial UART with sequence number 0 as
the console, but if no UART has sequence number 0, then we can fall back
to just using the first UART (index 0).
The device tree offset function is useful for buses, where they want to
locate one of their children. The device tree can be scanned to find the
offset of each child, and that offset can then find the device.
Signed-off-by: Simon Glass <sjg@chromium.org>
In U-Boot it is pretty common to number devices from 0 and access them
on the command line using this numbering. While it may come to pass that
we will move away from this numbering, the possibility seems remote at
present.
Given that devices within a uclass will have an implied numbering, it
makes sense to build this into driver model as a core feature. The cost
is fairly small in terms of code and data space.
With each uclass having numbered devices we can ask for SPI port 0 or
serial port 1 and receive a single device.
Devices typically request a sequence number using aliases in the device
tree. These are resolved when the device is probed, to deal with conflicts.
Sequence numbers need not be sequential and holes are permitted.
At present there is no support for sequence numbers using static platform
data. It could easily be added to 'struct driver_info' if needed, but it
seems better to add features as we find a use for them, and the use of -1
to mean 'no sequence' makes the default value somewhat painful.
Signed-off-by: Simon Glass <sjg@chromium.org>
Driver model currently only operates after relocation is complete. In this
state U-Boot typically has a small amount of memory available. In adding
support for driver model prior to relocation we must try to use as little
memory as possible.
In addition, on some machines the memory has not be inited and/or the CPU
is not running at full speed or the data cache is off. These can reduce
execution performance, so the less initialisation that is done before
relocation the better.
An immediately-obvious improvement is to only initialise drivers which are
actually going to be used before relocation. On many boards the only such
driver is a serial UART, so this provides a very large potential benefit.
Allow drivers to mark themselves as 'pre-reloc' which means that they will
be initialised prior to relocation. This can be done either with a driver
flag or with a 'dm,pre-reloc' device tree property.
To support this, the various dm scanning function now take a 'pre_reloc_only'
parameter which indicates that only drivers marked pre-reloc should be
bound.
Signed-off-by: Simon Glass <sjg@chromium.org>
There is a spelling mistake and two functions are missing comments
altogether. Also the flags declaration is correct, but doesn't follow
style. Finally, the uclass_get_device() function has some errors in
its documentation.
Fix these problems.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Marek Vasut <marex@denx.de>
using UBI and DM together leads in compiler error, as
both define a "struct device", so rename "struct device"
in include/dm/device.h to "struct udevice", as we use
linux code (MTD/UBI/UBIFS some USB code,...) and cannot
change the linux "struct device"
Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: 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>
