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path: root/drivers/core/syscon-uclass.c
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2018-05-07syscon: add Linux-compatible syscon APIMasahiro Yamada
The syscon implementation in U-Boot is different from that in Linux. Thus, DT files imported from Linux do not work for U-Boot. In U-Boot driver model, each node is bound to a dedicated driver that is the most compatible to it. This design gets along with the concept of DT, and the syscon in Linux originally worked like that. However, Linux commit bdb0066df96e ("mfd: syscon: Decouple syscon interface from platform devices") changed the behavior because it is useful to let a device bind to another driver, but still work as a syscon provider. That change had happened before U-Boot initially supported the syscon driver by commit 6f98b7504f70 ("dm: Add support for generic system controllers (syscon)"). So, the U-Boot's syscon works differently from the beginning. I'd say this is mis-implementation given that DT is not oriented to a particular project, but Linux is the canon of DT in practice. The problem typically arises in the combination of "syscon" and "simple-mfd" compatibles. In Linux, they are orthogonal, i.e., the order between "syscon" and "simple-mfd" does not matter at all. Assume the following compatible. compatible = "foo,bar-syscon", "syscon", "simple-mfd"; In U-Boot, this device node is bound to the syscon driver (driver/core/syscon-uclass.c) since the "syscon" is found to be the most compatible. Then, syscon_get_regmap() succeeds. However, compatible = "foo,bar-syscon", "simple-mfd", "syscon"; does not work because this node is bound to the simple-bus driver (drivers/core/simple-bus.c) in favor of "simple-mfd" compatible. The compatible string "syscon" is just dismissed. Moreover, compatible = "foo,bar-syscon", "syscon"; works like the first case because the syscon driver populates the child devices. This is wrong because populating children is the job of "simple-mfd" (or "simple-bus"). This commit ports syscon_node_to_regmap() from Linux. This API does not require the given node to be bound to a driver in any way. Reported-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-05-07regmap: change regmap_init_mem() to take ofnode instead udeviceMasahiro Yamada
Currently, regmap_init_mem() takes a udevice. This requires the node has already been associated with a device. It prevents syscon/regmap from behaving like those in Linux. Change the first argumenet to take a device node. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Neil Armstrong <narmstrong@baylibre.com> Reviewed-by: Simon Glass <sjg@chromium.org>
2018-05-07SPDX: Convert all of our single license tags to Linux Kernel styleTom Rini
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>
2017-08-17dm: core: Avoid calling dm_scan_fdt_dev() with of-platdataSimon Glass
We cannot call dm_scan_fdt_dev() with of-platdata since there is no device tree. Fix this with an #if check. Fixes: 3be9a37 (dm: syscon: scan sub-nodes of the syscon node) Signed-off-by: Simon Glass <sjg@chromium.org>
2016-09-21dm: syscon: Provide a generic syscon driverPaul Burton
Provide a trivial syscon driver matching the generic "syscon" compatible string, allowing for simple system controllers to be used without a custom driver just as in Linux. Signed-off-by: Paul Burton <paul.burton@imgtec.com>
2016-07-14dm: syscon: Add support for of-platdataSimon Glass
Provide a new function which can cope with obtaining information from of-platdata instead of the device tree. Signed-off-by: Simon Glass <sjg@chromium.org>
2016-03-17syscon: Avoid returning a device on failureSimon Glass
If the device cannot be probed, syscon_get_by_driver_data() will still return a useful value in its devp parameter. Ensure that it returns NULL instead. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2016-01-24dm: syscon: Allow finding devices by driver dataSimon Glass
We have a way to find a regmap by its syscon driver data value. Add the same for syscon itself. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2015-07-21dm: core: Add device checking to syscon_get_regmap()Simon Glass
This function can only handle a syscon device. It is possible that someone will make a mistake, so add a check for this. Also we should return -ENODEV when a device cannot be found, so update the syscon_get_regmap_by_driver_data() to follow this convention. Signed-off-by: Simon Glass <sjg@chromium.org>
2015-07-21dm: Add support for generic system controllers (syscon)Simon Glass
Many SoCs have a number of system controllers which are dealt with as a group by a single driver. It is a pain to have to add lots of compatible strings and/or separate drivers for each. Instead we can identify the controllers by a number and request the address of the one we want. Add a simple implementation of this which can be used by SoC driver code. Signed-off-by: Simon Glass <sjg@chromium.org>