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@xxxxxxxxxxxxx/
2. https://lore.kernel.org/all/20231027033104.1348921-1-chris.packham@xxxxxxxxxxxxxxxxxxx/
3. https://lore.kernel.org/lkml/20191030120440.3699-1-peter.ujfalusi@xxxxxx/
4. https://lore.kernel.org/all/20211018234923.1769028-1-sean.anderson@xxxxxxxx/
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@xxxxxxxxxxxxxxxxxx/
Best regards,
Krzysztof
Cc: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
Cc: Bartosz Golaszewski <brgl@xxxxxxxx>
Cc: Sean Anderson <sean.anderson@xxxxxxxx>
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
--
2.34.1
