Some buses need to set up their devices before they can be used. This setup
may well be common to all buses in a particular uclass. Support a common
pre-probe method for the uclass, called before any bus devices are probed.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
For buses, after a child is bound, allow the uclass to perform some
processing. This can be used to figure out the address of the child (e.g.
the chip select for SPI slaves) so that it is ready to be probed.
This avoids bus drivers having to repeat the same process, which really
should be done by the uclass, since it is common.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
In many cases the per-child private data for a device's children is defined
by the uclass rather than the individual driver. For example, a SPI bus
needs to store information about each of its children, but all SPI drivers
store the same information. It makes sense to allow the uclass to define
this data.
If the driver provides a size value for its per-child private data, then use
it. Failng that, fall back to that provided by the uclass.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
At present we try to use the 'reg' property and device tree aliases to give
devices a sequence number. The 'reg' property is often actually a memory
address, so the sequence numbers thus-obtained are not useful. It would be
better if the devices were just sequentially numbered in that case. In fact
neither I2C nor SPI use this feature, so drop it.
Some devices need us to look up an alias to number them within the uclass.
Add a flag to control this, so it is not done unless it is needed.
Adjust the tests to test this new behaviour.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Allow parent drivers to be called when a new child is bound to them. This
allows a bus to set up information it needs for that child.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
In many cases the child platform data for a device's children is defined by
the uclass rather than the individual devices. For example, a SPI bus needs
to know the chip select and speed for each of its children. It makes sense
to allow this information to be defined the SPI uclass rather than each
individual driver.
If the device provides a size value for its child platdata, then use it.
Failng that, fall back to that provided by the uclass.
Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
For buses it is common for parents to need to know the address of the child
on the bus, the bus speed to use for that child, and other information. This
can be provided in platform data attached to each child.
Add driver model support for this, including auto-allocation which can be
requested using a new property to specify the size of the data.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.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>
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>
At present only root nodes in the device tree are scanned for devices.
But some devices can have children. For example a SPI bus may have
several children for each of its chip selects.
Add a function which scans subnodes and binds devices for each one. This
can be used for the root node scan also, so change it.
A device can call this function in its bind() or probe() methods to bind
its children.
Signed-off-by: Simon Glass <sjg@chromium.org>
