This adds support for "nvmem cells" as seen in Linux. The nvmem device
class in Linux is used for various assorted ROMs and EEPROMs. In this
sense, it is similar to UCLASS_MISC, but also includes
UCLASS_I2C_EEPROM, UCLASS_RTC, and UCLASS_MTD. New drivers corresponding
to a Linux-style nvmem device should be implemented as one of the
previously-mentioned uclasses. The nvmem API acts as a compatibility
layer to adapt the (slightly different) APIs of these uclasses. It also
handles the lookup of nvmem cells.
While nvmem devices can be accessed directly, they are most often used
by reading/writing contiguous values called "cells". Cells typically
hold information like calibration, versions, or configuration (such as
mac addresses).
nvmem devices can specify "cells" in their device tree:
qfprom: eeprom@700000 {
#address-cells = <1>;
#size-cells = <1>;
reg = <0x00700000 0x100000>;
/* ... */
tsens_calibration: calib@404 {
reg = <0x404 0x10>;
};
};
which can then be referenced like:
tsens {
/* ... */
nvmem-cells = <&tsens_calibration>;
nvmem-cell-names = "calibration";
};
The tsens driver could then read the calibration value like:
struct nvmem_cell cal_cell;
u8 cal[16];
nvmem_cell_get_by_name(dev, "calibration", &cal_cell);
nvmem_cell_read(&cal_cell, cal, sizeof(cal));
Because nvmem devices are not all of the same uclass, supported uclasses
must register a nvmem_interface struct. This allows CONFIG_NVMEM to be
enabled without depending on specific uclasses. At the moment,
nvmem_interface is very bare-bones, and assumes that no initialization
is necessary. However, this could be amended in the future.
Although I2C_EEPROM and MISC are quite similar (and could likely be
unified), they present different read/write function signatures. To
abstract over this, NVMEM uses the same read/write signature as Linux.
In particular, short read/writes are not allowed, which is allowed by
MISC.
The functionality implemented by nvmem cells is very similar to that
provided by i2c_eeprom_partition. "fixed-partition"s for eeproms does
not seem to have made its way into Linux or into any device tree other
than sandbox. It is possible that with the introduction of this API it
would be possible to remove it.
Signed-off-by: Sean Anderson <sean.anderson@seco.com>
This converts the existing client (aka clk.h) documentation to kernel doc
format, and adds it to the HTML docs. I have tried to preserve existing
comments as much as possible, refraining from semantic changes.
Signed-off-by: Sean Anderson <seanga2@gmail.com>
Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Link: https://lore.kernel.org/r/20211222171114.3091780-4-seanga2@gmail.com
[rebased onto u-boot/master and resolved conflicts]
Signed-off-by: Sean Anderson <seanga2@gmail.com>
Correct Sphinx style comments in include/dm/uclass.h
and add the driver model UCLASS API to the HTML documentation.
Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Correct Sphinx style comments in include/lmb.h
Add the logical memory block API to the HTML documentation.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Complete the Sphinx documentation in include/sysreset.h
Add the include to the generated HTML documentation of the U-Boot API.
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Sphinx 3 builds fail due to doc/develop/logging.rst producing duplicate
labels.
Include logging.h only once in the API section and use cross-references for
the enums log_level_t and log_category_t.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Some commands can get very unweildy if they have too many positional
arguments. Adding options makes them easier to read, remember, and
understand.
This implementation of getopt has been taken from barebox, which has had
option support for quite a while. I have made a few modifications to their
version, such as the removal of opterr in favor of a separate getopt_silent
function. In addition, I have moved all global variables into struct
getopt_context.
The getopt from barebox also re-orders the arguments passed to it so that
non-options are placed last. This allows users to specify options anywhere.
For example, `ls -l foo/ -R` would be re-ordered to `ls -l -R foo/` as
getopt parsed the options. However, this feature conflicts with the const
argv in cmd_tbl->cmd. This was originally added in 54841ab50c ("Make sure
that argv[] argument pointers are not modified."). The reason stated in
that commit is that hush requires argv to stay unmodified. Has this
situation changed? Barebox also uses hush, and does not have this problem.
Perhaps we could use their fix?
I have assigned maintenance of getopt to Simon Glass, as it is currently
only used by the log command. I would also be fine maintaining it.
Signed-off-by: Sean Anderson <seanga2@gmail.com>
This adds kerneldocs for <timer.h>.
I don't know who should maintain doc/api/timer.rst, since the timer
subsystem seems to be maintained by SoC maintainers. MAINTAINERS is left
un-updated for the moment.
Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
This normalizes the documentation to conform to kernel-doc style [1]. It
also moves the documentation for pinctrl_ops inline, and adds argument and
return-value documentation. I have kept the usual function style for these
comments. I could not find any existing examples of function documentation
inside structs.
[1] https://www.kernel.org/doc/html/latest/doc-guide/kernel-doc.html
Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Add the device firmware update functions to the generated HTML
documentation.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: Lukasz Majewski <lukma@denx.de>
Currently the Sphinx doc only contains API descriptions of several
U-Boot subsystems. For future extension, group these existing docs
into an API sub-directory.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
