Hi,
Patch #2 (cpufreq: do not open-code of_phandle_args_equal()) and patch #4 (reset: Instantiate reset GPIO controller for shared reset-gpios) depend on OF change (patch #1).
Changes in v5 ============= 1. Minor comments from Philipp: missing cleanup.h, correct indentation of pr_err(), shorten gpio_device_find_by_fwnode() line. 2. Acks/Rbs.
Changes in v4 ============= 1. New patches: of: add of_phandle_args_equal() helper cpufreq: do not open-code of_phandle_args_equal()
2. reset-gpio.c: - Drop unneeded comment (Bartosz), add Rb tag. - Do not assign of_node.
3. reset/core.c: - Implement most of Bartosz feedback (I responded to one which I did not implement) and comments from Philipp. - Expect either rcdev->of_args or rcdev->of_node. - Drop __reset_gpios_args_match() and use common helper (Philipp). - Move declarations of automatic-cleanup variables in __reset_add_reset_gpio_lookup() to place of use (Bartosz). - Separate gpio_device_get_label() and kstrdup() (Philipp). - Correct doc for __reset_add_reset_gpio_device(), rewrite few comments. - Drop unneeded "r" variable in __reset_find_rcdev() (Philipp). - Drop of_phandle_args initialization in __of_reset_control_get (Philipp). - Check if CONFIG_RESET_GPIO is enabled before trying to look up reset-gpios.
4. Drop Chris' patch: "i2c: muxes: pca954x: Allow sharing reset GPIO", because discussion is on going.
Changes in v3 ============= 1. reset-gpio.c: - Add reset_gpio_of_xlate (Philipp). - reset_gpio_of_args_put->reset_gpio_of_node_put (Philipp). - Expect via platdata of_phandle_args. - Do not call device_set_node() to attach itself to reset consumer (the final device). This was questionable idea in the first place. Bartosz suggested to use GPIO_LOOKUP to solve this.
2. reset/core.c, implement Philipp's feedback. That was a lot: - Commit msg fixes. - Add new platform_device earlier, when reset core found "reset-gpios" but not "resets". - Do not overwrite of_phandle_args. - Expect matching .of_reset_n_cells. - Pass of_phandle_args as platdata to reset-gpio. - Rename reset_gpio_device->reset_gpio_lookup and others. Fix few comments and code cleanup pointed on review. - From Bartosz: Use GPIO_LOOKUP and a lot of cleanup.h in __reset_add_reset_gpio_lookup().
3. Include here Chris' patch: "i2c: muxes: pca954x: Allow sharing reset GPIO".
Changes in v2 ============= 1. wsa884x.c: add missing return in wsa884x_get_reset(), correct comment. 2. qcom,wsa8840.yaml: fix oneOf syntax. 3. reset-gpio.c: - Fix smatch warning on platdata evaluation. - Parse GPIO args and store them in rc.of_args. 4. reset/core.c: - Revise approach based on Bartosz comments: parse the reset-gpios phandle with arguments, do not use deprecated API and do not rely on gpio_desc pointer. - Create a list of instantiated platform devices to avoid any duplicates. - After creating reset-gpio platform device, try to get new reset controller or return EPROBE_DEFER. - Drop the "cookie" member and add new "of_args" to "struct reset_controller_dev".
Description ===========
We have at least few cases where hardware engineers decided to use one powerdown/shutdown/reset GPIO line for multiple devices:
1. WSA884x (this and previous patch): https://lore.kernel.org/all/b7aeda24-d638-45b7-8e30-80d287f498f8@sirena.org.... 2. https://lore.kernel.org/all/20231027033104.1348921-1-chris.packham@alliedtel... 3. https://lore.kernel.org/lkml/20191030120440.3699-1-peter.ujfalusi@ti.com/ 4. https://lore.kernel.org/all/20211018234923.1769028-1-sean.anderson@seco.com/ 5. https://social.treehouse.systems/@marcan/111268780311634160
I try to solve my case, hopefuly Chris' (2), partially Sean's (4) and maybe Hectors (5), using Rob's suggestion:
https://lore.kernel.org/all/YXi5CUCEi7YmNxXM@robh.at.kernel.org/
Best regards, Krzysztof
Cc: Chris Packham chris.packham@alliedtelesis.co.nz Cc: Bartosz Golaszewski brgl@bgdev.pl Cc: Sean Anderson sean.anderson@seco.com
Krzysztof Kozlowski (6): of: Add of_phandle_args_equal() helper cpufreq: do not open-code of_phandle_args_equal() reset: gpio: Add GPIO-based reset controller reset: Instantiate reset GPIO controller for shared reset-gpios ASoC: dt-bindings: qcom,wsa8840: Add reset-gpios for shared line ASoC: codecs: wsa884x: Allow sharing reset GPIO
.../bindings/sound/qcom,wsa8840.yaml | 11 +- MAINTAINERS | 5 + drivers/reset/Kconfig | 9 + drivers/reset/Makefile | 1 + drivers/reset/core.c | 215 ++++++++++++++++-- drivers/reset/reset-gpio.c | 119 ++++++++++ include/linux/cpufreq.h | 3 +- include/linux/of.h | 16 ++ include/linux/reset-controller.h | 4 + sound/soc/codecs/wsa884x.c | 53 ++++- 10 files changed, 410 insertions(+), 26 deletions(-) create mode 100644 drivers/reset/reset-gpio.c