From 993bcaf32c494014f56357f6cdd87fdfaa4e4d11 Mon Sep 17 00:00:00 2001 From: Josua Mayer Date: Thu, 26 Feb 2026 15:21:11 +0200 Subject: mux: Add helper functions for getting optional and selected mux-state In-tree phy-can-transceiver and phy_rcar_gen3_usb2 have already implemented local versions of devm_mux_state_get_optional. The omap-i2c driver gets and selects an optional mux in its probe function without using any helper. Add new helper functions covering both aforementioned use-cases: - mux_control_get_optional: Get a mux-control if specified in dt, return NULL otherwise. - devm_mux_state_get_optional: Get a mux-state if specified in dt, return NULL otherwise. - devm_mux_state_get_selected: Get and select a mux-state specified in dt, return error otherwise. - devm_mux_state_get_optional_selected: Get and select a mux-state if specified in dt, return error or NULL. Existing mux_get helper function is changed to take an extra argument indicating whether the mux is optional. In this case no error is printed, and NULL returned in case of ENOENT. Calling code is adapted to handle NULL return case, and to pass optional argument as required. To support automatic deselect for _selected helper, a new structure is created storing an exit pointer similar to clock core which is called on release. To facilitate code sharing between optional/mandatory/selected helpers, a new internal helper function is added to handle quiet (optional) and verbose (mandatory) errors, as well as storing the correct callback for devm release: __devm_mux_state_get Due to this structure devm_mux_state_get_*_selected can no longer print a useful error message when select fails. Instead callers should print errors where needed. Commit e153fdea9db04 ("phy: can-transceiver: Re-instate "mux-states" property presence check") noted that "mux_get() always prints an error message in case of an error, including when the property is not present, confusing the user." The first error message covers the case that a mux name is not matched in dt. The second error message is based on of_parse_phandle_with_args return value. In optional case no error is printed and NULL is returned. This ensures that the new helper functions will not confuse the user either. With the addition of optional helper functions it became clear that drivers should compile and link even if CONFIG_MULTIPLEXER was not enabled. Add stubs for all symbols exported by mux core. Acked-by: Wolfram Sang Signed-off-by: Josua Mayer Signed-off-by: Ulf Hansson --- include/linux/mux/consumer.h | 108 +++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 104 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/include/linux/mux/consumer.h b/include/linux/mux/consumer.h index 2e25c838f831..a961861a503b 100644 --- a/include/linux/mux/consumer.h +++ b/include/linux/mux/consumer.h @@ -16,6 +16,8 @@ struct device; struct mux_control; struct mux_state; +#if IS_ENABLED(CONFIG_MULTIPLEXER) + unsigned int mux_control_states(struct mux_control *mux); int __must_check mux_control_select_delay(struct mux_control *mux, unsigned int state, @@ -54,11 +56,109 @@ int mux_control_deselect(struct mux_control *mux); int mux_state_deselect(struct mux_state *mstate); struct mux_control *mux_control_get(struct device *dev, const char *mux_name); +struct mux_control *mux_control_get_optional(struct device *dev, const char *mux_name); void mux_control_put(struct mux_control *mux); -struct mux_control *devm_mux_control_get(struct device *dev, - const char *mux_name); -struct mux_state *devm_mux_state_get(struct device *dev, - const char *mux_name); +struct mux_control *devm_mux_control_get(struct device *dev, const char *mux_name); +struct mux_state *devm_mux_state_get(struct device *dev, const char *mux_name); +struct mux_state *devm_mux_state_get_optional(struct device *dev, const char *mux_name); +struct mux_state *devm_mux_state_get_selected(struct device *dev, const char *mux_name); +struct mux_state *devm_mux_state_get_optional_selected(struct device *dev, const char *mux_name); + +#else + +static inline unsigned int mux_control_states(struct mux_control *mux) +{ + return 0; +} +static inline int __must_check mux_control_select_delay(struct mux_control *mux, + unsigned int state, unsigned int delay_us) +{ + return -EOPNOTSUPP; +} +static inline int __must_check mux_state_select_delay(struct mux_state *mstate, + unsigned int delay_us) +{ + return -EOPNOTSUPP; +} +static inline int __must_check mux_control_try_select_delay(struct mux_control *mux, + unsigned int state, + unsigned int delay_us) +{ + return -EOPNOTSUPP; +} +static inline int __must_check mux_state_try_select_delay(struct mux_state *mstate, + unsigned int delay_us) +{ + return -EOPNOTSUPP; +} + +static inline int __must_check mux_control_select(struct mux_control *mux, + unsigned int state) +{ + return -EOPNOTSUPP; +} + +static inline int __must_check mux_state_select(struct mux_state *mstate) +{ + return -EOPNOTSUPP; +} + +static inline int __must_check mux_control_try_select(struct mux_control *mux, + unsigned int state) +{ + return -EOPNOTSUPP; +} + +static inline int __must_check mux_state_try_select(struct mux_state *mstate) +{ + return -EOPNOTSUPP; +} + +static inline int mux_control_deselect(struct mux_control *mux) +{ + return -EOPNOTSUPP; +} +static inline int mux_state_deselect(struct mux_state *mstate) +{ + return -EOPNOTSUPP; +} + +static inline struct mux_control *mux_control_get(struct device *dev, const char *mux_name) +{ + return ERR_PTR(-EOPNOTSUPP); +} +static inline struct mux_control *mux_control_get_optional(struct device *dev, + const char *mux_name) +{ + return NULL; +} +static inline void mux_control_put(struct mux_control *mux) {} + +static inline struct mux_control *devm_mux_control_get(struct device *dev, const char *mux_name) +{ + return ERR_PTR(-EOPNOTSUPP); +} +static inline struct mux_state *devm_mux_state_get(struct device *dev, const char *mux_name) +{ + return ERR_PTR(-EOPNOTSUPP); +} +static inline struct mux_state *devm_mux_state_get_optional(struct device *dev, + const char *mux_name) +{ + return NULL; +} +static inline struct mux_state *devm_mux_state_get_selected(struct device *dev, + const char *mux_name) +{ + return ERR_PTR(-EOPNOTSUPP); +} +static inline struct mux_state *devm_mux_state_get_optional_selected(struct device *dev, + const char *mux_name) +{ + return NULL; +} + +#endif /* CONFIG_MULTIPLEXER */ #endif /* _LINUX_MUX_CONSUMER_H */ -- cgit v1.2.3