The pinmux property allows for smaller and more compact device trees,
especially when there are many pins which need to be assigned individually.
Instead of specifying an array of strings to be parsed as pins and a
function property, the pinmux property contains an array of integers
representing pinmux groups. A pinmux group consists of the pin identifier
and mux settings represented as a single integer or an array of integers.
Each individual pin controller driver specifies the exact format of a
pinmux group. As specified in the Linux documentation, a pinmux group may
be multiple integers long. However, no existing drivers use multi-integer
pinmux groups, so I have chosen to omit this feature. This makes the
implementation easier, since there is no need to allocate a buffer to do
endian conversions.
Support for the pinmux property is done differently than in Linux. As far
as I can tell, inversion of control is used when implementing support for
the pins and groups properties to avoid allocating. This results in some
duplication of effort; every property in a config node is parsed once for
each pin in that node. This is not such an overhead with pins and groups
properties, since having multiple pins in one config node does not occur
especially often. However, the semantics of the pinmux property make such a
configuration much more appealing. A future patch could parse all config
properties at once and store them in an array. This would make it easier to
create drivers which do not function solely as callbacks from
pinctrl-generic.
This commit increases the size of the sandbox build by approximately 48
bytes. However, it also decreases the size of the K210 device tree by 2
KiB from the previous version of this series.
The documentation has been updated from the last Linux commit before it was
split off into yaml files.
Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Migrate pinctrl-generic to livetree:
- dev_for_each_property
- dev_read_prop_by_prop
- dev_read_string_count
- dev_read_string_index
and get rid of DECLARE_GLOBAL_DATA_PTR.
This patch solves the parsing issue during sandbox tests for pin
configuration (OF_LIVE is activated in sandbox_defconfig
and sub node are not correctly parsed in
pinctrl_generic_set_state_subnode with fdt lib API).
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
At present dm/device.h includes the linux-compatible features. This
requires including linux/compat.h which in turn includes a lot of headers.
One of these is malloc.h which we thus end up including in every file in
U-Boot. Apart from the inefficiency of this, it is problematic for sandbox
which needs to use the system malloc() in some files.
Move the compatibility features into a separate header file.
Signed-off-by: Simon Glass <sjg@chromium.org>
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from. So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry. Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.
In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.
This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents. There's also a few places where I found we did not have a tag
and have introduced one.
Signed-off-by: Tom Rini <trini@konsulko.com>
This header includes things that are needed to make driver build. Adjust
existing users to include that always, even if other dm/ includes are
present
Signed-off-by: Simon Glass <sjg@chromium.org>
At present devices use a simple integer offset to record the device tree
node associated with the device. In preparation for supporting a live
device tree, which uses a node pointer instead, refactor existing code to
access this field through an inline function.
Signed-off-by: Simon Glass <sjg@chromium.org>
Commit b02e4044ff ("libfdt: Bring in upstream stringlist
functions") broke codying style in some places especially
by inserting an extra whitespace before fdt_stringlist_count().
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Simon Glass <sjg@chromium.org>
These have now landed upstream. The naming is different and in one case the
function signature has changed. Update the code to match.
This applies the following upstream commits by
Thierry Reding <treding@nvidia.com> :
604e61e fdt: Add functions to retrieve strings
8702bd1 fdt: Add a function to get the index of a string
2218387 fdt: Add a function to count strings
Signed-off-by: Simon Glass <sjg@chromium.org>
In cases where the pins and groups definitions are in a sub-node, as:
uart_a {
mux {
groups = "uart_tx_a", "uart_rx_a";
function = "uart_a";
};
};
pinctrl_generic_set_state_subnode() returns an error for the top-level
node and pinctrl_generic_set_state() fails. Instead, return success so
that the child nodes are tried.
Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Masahiro Yamada <yamada.masahiro@socionext.com>
This creates a new framework for handling of pin control devices,
i.e. devices that control different aspects of package pins.
This uclass handles pinmuxing and pin configuration; pinmuxing
controls switching among silicon blocks that share certain physical
pins, pin configuration handles electronic properties such as pin-
biasing, load capacitance etc.
This framework can support the same device tree bindings, but if you
do not need full interface support, you can disable some features to
reduce memory foot print. Typically around 1.5KB is necessary to
include full-featured uclass support on ARM board (CONFIG_PINCTRL +
CONFIG_PINCTRL_FULL + CONFIG_PINCTRL_GENERIC + CONFIG_PINCTRL_PINMUX),
for example.
We are often limited on code size for SPL. Besides, we still have
many boards that do not support device tree configuration. The full
pinctrl, which requires OF_CONTROL, does not make sense for those
boards. So, this framework also has a Do-It-Yourself (let's say
simple pinctrl) interface. With CONFIG_PINCTRL_FULL disabled, the
uclass itself provides no systematic mechanism for identifying the
peripheral device, applying pinctrl settings, etc. They must be
done in each low-level driver. In return, you can save much memory
footprint and it might be useful especially for SPL.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Simon Glass <sjg@chromium.org>
