This is useful to check which uclass a device is in.
Signed-off-by: NSimon Glass <sjg@chromium.org>
Reviewed-by: NMasahiro 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: NSimon Glass <sjg@chromium.org>
Reviewed-by: NMasahiro 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: NMasahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: NSimon 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: NSimon Glass <sjg@chromium.org>
Reviewed-by: NMasahiro Yamada <yamada.m@jp.panasonic.com>

When using allocated platform data, allocate it when we bind the device.
This makes it possible to fill in this information before the device is
probed.

This fits with the platform data model (when not using device tree),
since platform data exists at bind-time.
Signed-off-by: NSimon Glass <sjg@chromium.org>
Reviewed-by: NMasahiro Yamada <yamada.m@jp.panasonic.com>

Make the error handling more standard to make it easier to build on top of
it. Also correct a bug in the error path where there is no parent.
Signed-off-by: NSimon Glass <sjg@chromium.org>
Reviewed-by: NMasahiro Yamada <yamada.m@jp.panasonic.com>

The root device corresponds to the root device tree node, so set this up.
Also add a few notes to the documentation.
Signed-off-by: NSimon Glass <sjg@chromium.org>

Some of these are missing a newline. Add it.
Signed-off-by: NSimon Glass <sjg@chromium.org>

These conditions never happen.
 - There is no real uclass with UCLASS_INVALID id.
 - uclass never becomes NULL because ll_entry_start() always returns
   a valid pointer.
Signed-off-by: NMasahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: NSimon Glass <sjg@chromium.org>

The variable "drv" never becomes NULL because ll_entry_start()
always returns a valid pointer even if there are no entries.

The case "n_ents == 0" is covered by the following "for" loop.
Signed-off-by: NMasahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: NSimon Glass <sjg@chromium.org>

If the variable "ret" is equal to "-ENOENT", it is trapped at [1] and
never reaches [2].  At [3], the condition "ret != -ENOENT" is always
true.

  if (ret == -ENOENT) {                       <------------------ [1]
          continue;
  } else if (ret == -ENODEV) {
          dm_dbg("Device '%s' has no compatible string\n", name);
          break;
  } else if (ret) {                           <------------------ [2]
          dm_warn("Device tree error at offset %d\n", offset);
          if (!result || ret != -ENOENT)      <------------------ [3]
                  result = ret;
          break;
  }
Signed-off-by: NMasahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: NSimon Glass <sjg@chromium.org>

Signed-off-by: NMasahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: NSimon Glass <sjg@chromium.org>

In some cases we need to manually bind a device to a particular driver.
Add a function to do this.
Signed-off-by: NSimon Glass <sjg@chromium.org>
Reviewed-by: NJagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
Acked-by: NHeiko Schocher <hs@denx.de>

Add dev_get_parent() as a convenience to obtain the parent of a device.
Signed-off-by: NSimon Glass <sjg@chromium.org>
Reviewed-by: NTom Rini <trini@ti.com>
Acked-by: NHeiko Schocher <hs@denx.de>

When the device is created from a device tree node, it matches a compatible
string. Allow access to that string and the associated data.
Signed-off-by: NSimon Glass <sjg@chromium.org>
Reviewed-by: NTom Rini <trini@ti.com>
Acked-by: NHeiko Schocher <hs@denx.de>

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: NSimon Glass <sjg@chromium.org>
Reviewed-by: NTom Rini <trini@ti.com>

Create entries of CONFIG_DM, CONFIG_DM_SERIAL, CONFIG_DM_GPIO
and CONFIG_DM_SPI.
Signed-off-by: NMasahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: NSimon Glass <sjg@chromium.org>

Add a driver for the simple-bus nodes, which allows devices within these
nodes to be bound.
Signed-off-by: NSimon Glass <sjg@chromium.org>

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: NSimon Glass <sjg@chromium.org>
Acked-by: NJagannadha 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: NSimon Glass <sjg@chromium.org>
Acked-by: NJagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>

if (strncmp(name, entry->name, len))
                continue;

        /* Full match */
        if (len == strlen(entry->name))
                return entry;

is equivalent to:

        if (!strcmp(name, entry->name))
                return entry;

The latter is simpler.
Signed-off-by: NMasahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: NSimon Glass <sjg@chromium.org>
Acked-by: NIgor Grinberg <grinberg@compulab.co.il>

The function uclass_add() checks uc_drv->ops as follows:

        if (uc_drv->ops) {
                dm_warn("No ops for uclass id %d\n", id);
                return -EINVAL;
        }

It seems odd because it warns "No ops" when uc_drv->ops has
non-NULL pointer.  (Looks opposite.)

Anyway, most of UCLASS_DRIVER entries have no .ops member.
This check makes no sense.
Signed-off-by: NMasahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: NSimon Glass <sjg@chromium.org>

[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: NMasahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: NMarek Vasut <marex@denx.de>

This would be useful to start moving various config options.
Signed-off-by: NMasahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: NSimon Glass <sjg@chromium.org>
Tested-by: NSimon Glass <sjg@chromium.org>

Since dev->req_seq value is initialized from "reg" property of fdt node,
there is posibility, that address value contained in fdt is greater than
INT_MAX, and then value in dev->req_seq is negative which led to probe()
fail.

This patch fix this problem by ensuring that req_seq is positive, unless
it's one of errno codes.
Signed-off-by: NRobert Baldyga <r.baldyga@samsung.com>
Acked-by: NSimon Glass <sjg@chromium.org>

The sequence number support in driver model requires device tree control.
It should be skipped if CONFIG_OF_CONTROL is not defined, and should not
require functions from fdtdec.
Signed-off-by: NSimon Glass <sjg@chromium.org>

Allow the caller to find out the device that was bound in response to this
call.
Signed-off-by: NSimon Glass <sjg@chromium.org>

Some boards will have devices which are not in the device tree and do not
have platform data. They may be programnatically created, for example.
Add a hook which boards can use to bind those devices early in boot.
Signed-off-by: NSimon Glass <sjg@chromium.org>

Add a debug message for when a device tree node has no driver. Also reword
the warning when a device fails to bind, which was misleading.
Signed-off-by: NSimon 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: NSimon 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: NSimon 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: NSimon 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: NSimon Glass <sjg@chromium.org>

Don't allow access to uclasses before they have been initialised.
Signed-off-by: NSimon Glass <sjg@chromium.org>

Each device that was bound from a device tree has an node that caused it to
be bound. Add functions that find and return a device based on a device tree
offset.
Signed-off-by: NSimon 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: NSimon Glass <sjg@chromium.org>

Several functions will use this same pattern, so bring it into a function.
Signed-off-by: NSimon Glass <sjg@chromium.org>

Initialise devices marked 'pre-reloc' and make them available prior to
relocation. Note that this requires pre-reloc malloc() to be available.
Signed-off-by: NSimon 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: NSimon Glass <sjg@chromium.org>

Add a new method which removes and unbinds all drivers.
Signed-off-by: NSimon Glass <sjg@chromium.org>
Acked-by: NMarek Vasut <marex@denx.de>