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2024-02-21reset: Instantiate reset GPIO controller for shared reset-gpiosKrzysztof Kozlowski1-0/+4
Devices sharing a reset GPIO could use the reset framework for coordinated handling of that shared GPIO line. We have several cases of such needs, at least for Devicetree-based platforms. If Devicetree-based device requests a reset line, while "resets" Devicetree property is missing but there is a "reset-gpios" one, instantiate a new "reset-gpio" platform device which will handle such reset line. This allows seamless handling of such shared reset-gpios without need of changing Devicetree binding [1]. To avoid creating multiple "reset-gpio" platform devices, store the Devicetree "reset-gpios" GPIO specifiers used for new devices on a linked list. Later such Devicetree GPIO specifier (phandle to GPIO controller, GPIO number and GPIO flags) is used to check if reset controller for given GPIO was already registered. If two devices have conflicting "reset-gpios" property, e.g. with different ACTIVE_xxx flags, this would allow to spawn two separate "reset-gpio" devices, where the second would fail probing on busy GPIO request. Link: https://lore.kernel.org/all/YXi5CUCEi7YmNxXM@robh.at.kernel.org/ [1] Cc: Bartosz Golaszewski <brgl@bgdev.pl> Cc: Chris Packham <chris.packham@alliedtelesis.co.nz> Cc: Sean Anderson <sean.anderson@seco.com> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Acked-by: Linus Walleij <linus.walleij@linaro.org> Link: https://lore.kernel.org/r/20240129115216.96479-5-krzysztof.kozlowski@linaro.org Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2021-06-09reset: Add compile-test stubsThierry Reding1-0/+22
Add stubs for the reset controller registration functions to allow building reset controller provider drivers with the COMPILE_TEST Kconfig option enabled. Reported-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Suggested-by: Dmitry Osipenko <digetx@gmail.com> Signed-off-by: Thierry Reding <treding@nvidia.com> Link: https://lore.kernel.org/r/20210609112806.3565057-3-thierry.reding@gmail.com Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2019-12-05Merge tag 'armsoc-drivers' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc Pull ARM SoC driver updates from Olof Johansson: "Various driver updates for platforms: - A larger set of work on Tegra 2/3 around memory controller and regulator features, some fuse cleanups, etc.. - MMP platform drivers, in particular for USB PHY, and other smaller additions. - Samsung Exynos 5422 driver for DMC (dynamic memory configuration), and ASV (adaptive voltage), allowing the platform to run at more optimal operating points. - Misc refactorings and support for RZ/G2N and R8A774B1 from Renesas - Clock/reset control driver for TI/OMAP - Meson-A1 reset controller support - Qualcomm sdm845 and sda845 SoC IDs for socinfo" * tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (150 commits) firmware: arm_scmi: Fix doorbell ring logic for !CONFIG_64BIT soc: fsl: add RCPM driver dt-bindings: fsl: rcpm: Add 'little-endian' and update Chassis definition memory: tegra: Consolidate registers definition into common header memory: tegra: Ensure timing control debug features are disabled memory: tegra: Introduce Tegra30 EMC driver memory: tegra: Do not handle error from wait_for_completion_timeout() memory: tegra: Increase handshake timeout on Tegra20 memory: tegra: Print a brief info message about EMC timings memory: tegra: Pre-configure debug register on Tegra20 memory: tegra: Include io.h instead of iopoll.h memory: tegra: Adapt for Tegra20 clock driver changes memory: tegra: Don't set EMC rate to maximum on probe for Tegra20 memory: tegra: Add gr2d and gr3d to DRM IOMMU group memory: tegra: Set DMA mask based on supported address bits soc: at91: Add Atmel SFR SN (Serial Number) support memory: atmel-ebi: switch to SPDX license identifiers memory: atmel-ebi: move NUM_CS definition inside EBI driver soc: mediatek: Refactor bus protection control soc: mediatek: Refactor sram control ...
2019-10-28reset: fix reset_control_ops kerneldoc commentRandy Dunlap1-1/+1
Add a missing short description to the reset_control_ops documentation. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> [p.zabel@pengutronix.de: rebased and updated commit message] Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2019-10-24reset: improve of_xlate documentationPhilipp Zabel1-1/+2
Mention of_reset_simple_xlate as the default if of_xlate is not set. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2019-10-24reset: fix reset_control_lookup kerneldoc commentPhilipp Zabel1-1/+1
Add a missing colon to fix a documentation build warning: ./include/linux/reset-controller.h:45: warning: Function parameter or member 'con_id' not described in 'reset_control_lookup' Fixes: 6691dffab0ab ("reset: add support for non-DT systems") Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2018-03-27reset: modify the way reset lookup works for board filesBartosz Golaszewski1-6/+8
Commit 7af1bb19f1d7 ("reset: add support for non-DT systems") introduced reset control lookup mechanism for boards that still use board files. The routine used to register lookup entries takes the corresponding reset_controlled_dev structure as argument. It's been determined however that for the first user of this new interface - davinci psc driver - it will be easier to register the lookup entries using the reset controller device name. This patch changes the way lookup entries are added. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> [p.zabel@pengutronix.de: added missing ERR_PTR] Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2018-03-27reset: add support for non-DT systemsBartosz Golaszewski1-0/+28
The reset framework only supports device-tree. There are some platforms however, which need to use it even in legacy, board-file based mode. An example of such architecture is the DaVinci family of SoCs which supports both device tree and legacy boot modes and we don't want to introduce any regressions. We're currently working on converting the platform from its hand-crafted clock API to using the common clock framework. Part of the overhaul will be representing the chip's power sleep controller's reset lines using the reset framework. This changeset extends the core reset code with a new reset lookup entry structure. It contains data allowing the reset core to associate reset lines with devices by comparing the dev_id and con_id strings. It also provides a function allowing drivers to register lookup entries with the framework. The new lookup function is only called as a fallback in case the of_node field is NULL and doesn't change anything for current users. Tested with a dummy reset driver with several lookup entries. An example lookup table registration from a driver can be found below: static struct reset_control_lookup foobar_reset_lookup[] = { RESET_LOOKUP("foo.0", "foo", 15), RESET_LOOKUP("bar.0", NULL, 5), }; foobar_probe() { ... reset_controller_add_lookup(&rcdev, foobar_reset_lookup, ARRAY_SIZE(foobar_reset_lookup)); ... } Cc: Sekhar Nori <nsekhar@ti.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: David Lechner <david@lechnology.com> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2017-11-02License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman1-0/+1
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-30reset: add devm_reset_controller_register APIMasahiro Yamada1-0/+4
Add a device managed API for reset_controller_register(). This helps in reducing code in .remove callbacks and sometimes dropping .remove callbacks entirely. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2016-03-30reset: Share struct reset_control between reset_control_get callsHans de Goede1-0/+2
Now that struct reset_control no longer stores the device pointer for the device calling reset_control_get we can share a single struct reset_control when multiple calls to reset_control_get are made for the same reset line (same id / index). This is a preparation patch for adding support for shared reset lines. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2016-01-25reset: Make reset_control_ops constMaxime Ripard1-1/+1
The ops pointer is holding a pointer to a structure that is usually not modified. Make it const. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2014-10-20reset: add reset_control_status helper functionDinh Nguyen1-0/+2
There are cases where a system will want to read a reset status bit before doing any other toggling. Add a reset_control_status helper function to the reset controller API. Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
2014-01-17reset: Silence warning in reset-controller.hStephen Boyd1-0/+1
If a user of <linux/reset-controller.h> doesn't include <linux/of.h> before including reset-controller.h they'll get a warning as follows: include/linux/reset-controller.h:44:17: warning: 'struct of_phandle_args' declared inside parameter list This is because of_phandle_args is not forward declared. Add the declaration to silence this warning. Acked-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Mike Turquette <mturquette@linaro.org>
2013-04-12reset: Add reset controller APIPhilipp Zabel1-0/+51
This adds a simple API for devices to request being reset by separate reset controller hardware and implements the reset signal device tree binding. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Reviewed-by: Stephen Warren <swarren@nvidia.com> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> Reviewed-by: Marek Vasut <marex@denx.de> Reviewed-by: Pavel Machek <pavel@ucw.cz>