diff options
| author | Frank Li <Frank.Li@nxp.com> | 2026-05-05 02:54:38 +0300 |
|---|---|---|
| committer | Linus Walleij <linusw@kernel.org> | 2026-05-05 15:48:12 +0300 |
| commit | 418a2bbdee2927d543db6913073d0e7ec8b540ee (patch) | |
| tree | 65c97fd40d32efb1a0ec9d97e58c05b1fbf8b27d | |
| parent | aaaf31be04260316036f50a05b7d015c0d36b55a (diff) | |
| download | linux-418a2bbdee2927d543db6913073d0e7ec8b540ee.tar.xz | |
pinctrl: add optional .release_mux() callback
Add an optional .release_mux() callback to struct pinmux_ops.
Some drivers acquire additional resources in .set_mux(), such as software
locks. These resources may need to be released when the mux function is no
longer active. Introducing a dedicated .release_mux() callback allows
drivers to clean up such resources.
The callback is optional and does not affect existing drivers.
Commit 2243a87d90b42 ("pinctrl: avoid duplicated calling
enable_pinmux_setting for a pin") removed the .disable() callback
to resolve two issues:
1. desc->mux_usecount increasing monotonically
2. Hardware glitches caused by repeated .disable()/.enable() calls
Adding .release_mux() does not reintroduce those problems. The callback is
intended only for releasing driver-side resources (e.g. locks) and must not
modify hardware registers.
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>
| -rw-r--r-- | drivers/pinctrl/pinmux.c | 5 | ||||
| -rw-r--r-- | include/linux/pinctrl/pinmux.h | 5 |
2 files changed, 10 insertions, 0 deletions
diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c index 3a8dd184ba3d..c705bc182266 100644 --- a/drivers/pinctrl/pinmux.c +++ b/drivers/pinctrl/pinmux.c @@ -517,6 +517,7 @@ void pinmux_disable_setting(const struct pinctrl_setting *setting) { struct pinctrl_dev *pctldev = setting->pctldev; const struct pinctrl_ops *pctlops = pctldev->desc->pctlops; + const struct pinmux_ops *ops = pctldev->desc->pmxops; int ret = 0; const unsigned int *pins = NULL; unsigned int num_pins = 0; @@ -563,6 +564,10 @@ void pinmux_disable_setting(const struct pinctrl_setting *setting) pins[i], desc->name, gname); } } + + if (ops->release_mux) + ops->release_mux(pctldev, setting->data.mux.func, + setting->data.mux.group); } #ifdef CONFIG_DEBUG_FS diff --git a/include/linux/pinctrl/pinmux.h b/include/linux/pinctrl/pinmux.h index 094bbe2fd6fd..77664937eeb2 100644 --- a/include/linux/pinctrl/pinmux.h +++ b/include/linux/pinctrl/pinmux.h @@ -51,6 +51,8 @@ struct pinctrl_gpio_range; * are handled by the pinmux subsystem. The @func_selector selects a * certain function whereas @group_selector selects a certain set of pins * to be used. On simple controllers the latter argument may be ignored + * @release_mux: Release software resources acquired by @set_mux. This callback + * must not change hardware state to avoid glitches when switching mux. * @gpio_request_enable: requests and enables GPIO on a certain pin. * Implement this only if you can mux every pin individually as GPIO. The * affected GPIO range is passed along with an offset(pin number) into that @@ -80,6 +82,9 @@ struct pinmux_ops { unsigned int selector); int (*set_mux) (struct pinctrl_dev *pctldev, unsigned int func_selector, unsigned int group_selector); + void (*release_mux) (struct pinctrl_dev *pctldev, + unsigned int func_selector, + unsigned int group_selector); int (*gpio_request_enable) (struct pinctrl_dev *pctldev, struct pinctrl_gpio_range *range, unsigned int offset); |