diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt index 7c1bb3d0c2229363fcc2eb5d729f911f59c258d9..a3e8bceb5f19b84e56a90a21f43d7b57333222f1 100644 --- a/Documentation/driver-model/devres.txt +++ b/Documentation/driver-model/devres.txt @@ -344,6 +344,7 @@ MUX devm_mux_chip_alloc() devm_mux_chip_register() devm_mux_control_get() + devm_mux_control_get_optional() PER-CPU MEM devm_alloc_percpu() diff --git a/drivers/mux/core.c b/drivers/mux/core.c index d1271c1ee23ced2c5da81826ec7fbdac02bd87c6..0f18ef79dc530b34e135cfd5ee0dbd7f001ca323 100644 --- a/drivers/mux/core.c +++ b/drivers/mux/core.c @@ -286,6 +286,9 @@ EXPORT_SYMBOL_GPL(devm_mux_chip_register); */ unsigned int mux_control_states(struct mux_control *mux) { + if (!mux) + return 0; + return mux->states; } EXPORT_SYMBOL_GPL(mux_control_states); @@ -335,6 +338,9 @@ int mux_control_select(struct mux_control *mux, unsigned int state) { int ret; + if (!mux) + return 0; + ret = down_killable(&mux->lock); if (ret < 0) return ret; @@ -367,6 +373,9 @@ int mux_control_try_select(struct mux_control *mux, unsigned int state) { int ret; + if (!mux) + return 0; + if (down_trylock(&mux->lock)) return -EBUSY; @@ -395,6 +404,9 @@ int mux_control_deselect(struct mux_control *mux) { int ret = 0; + if (!mux) + return 0; + if (mux->idle_state != MUX_IDLE_AS_IS && mux->idle_state != mux->cached_state) ret = mux_control_set(mux, mux->idle_state); @@ -420,14 +432,8 @@ static struct mux_chip *of_find_mux_chip_by_node(struct device_node *np) return dev ? to_mux_chip(dev) : NULL; } -/** - * mux_control_get() - Get the mux-control for a device. - * @dev: The device that needs a mux-control. - * @mux_name: The name identifying the mux-control. - * - * Return: A pointer to the mux-control, or an ERR_PTR with a negative errno. - */ -struct mux_control *mux_control_get(struct device *dev, const char *mux_name) +static struct mux_control * +__mux_control_get(struct device *dev, const char *mux_name, bool optional) { struct device_node *np = dev->of_node; struct of_phandle_args args; @@ -439,16 +445,22 @@ struct mux_control *mux_control_get(struct device *dev, const char *mux_name) if (mux_name) { index = of_property_match_string(np, "mux-control-names", mux_name); + if ((index == -EINVAL || index == -ENODATA) && optional) + return NULL; if (index < 0) { dev_err(dev, "mux controller '%s' not found\n", mux_name); return ERR_PTR(index); } + /* OF does point to a mux, so it's no longer optional */ + optional = false; } ret = of_parse_phandle_with_args(np, "mux-controls", "#mux-control-cells", index, &args); + if (ret == -ENOENT && optional) + return NULL; if (ret) { dev_err(dev, "%pOF: failed to get mux-control %s(%i)\n", np, mux_name ?: "", index); @@ -481,8 +493,35 @@ struct mux_control *mux_control_get(struct device *dev, const char *mux_name) return &mux_chip->mux[controller]; } + +/** + * mux_control_get() - Get the mux-control for a device. + * @dev: The device that needs a mux-control. + * @mux_name: The name identifying the mux-control. + * + * Return: A pointer to the mux-control, or an ERR_PTR with a negative errno. + */ +struct mux_control *mux_control_get(struct device *dev, const char *mux_name) +{ + return __mux_control_get(dev, mux_name, false); +} EXPORT_SYMBOL_GPL(mux_control_get); +/** + * mux_control_get_optional() - Get the optional mux-control for a device. + * @dev: The device that needs a mux-control. + * @mux_name: The name identifying the mux-control. + * + * Return: NULL if no mux with the provided name is found, a pointer to + * the named mux-control or an ERR_PTR with a negative errno. + */ +struct mux_control * +mux_control_get_optional(struct device *dev, const char *mux_name) +{ + return __mux_control_get(dev, mux_name, true); +} +EXPORT_SYMBOL_GPL(mux_control_get_optional); + /** * mux_control_put() - Put away the mux-control for good. * @mux: The mux-control to put away. @@ -491,6 +530,9 @@ EXPORT_SYMBOL_GPL(mux_control_get); */ void mux_control_put(struct mux_control *mux) { + if (!mux) + return; + put_device(&mux->chip->dev); } EXPORT_SYMBOL_GPL(mux_control_put); @@ -502,16 +544,8 @@ static void devm_mux_control_release(struct device *dev, void *res) mux_control_put(mux); } -/** - * devm_mux_control_get() - Get the mux-control for a device, with resource - * management. - * @dev: The device that needs a mux-control. - * @mux_name: The name identifying the mux-control. - * - * Return: Pointer to the mux-control, or an ERR_PTR with a negative errno. - */ -struct mux_control *devm_mux_control_get(struct device *dev, - const char *mux_name) +static struct mux_control * +__devm_mux_control_get(struct device *dev, const char *mux_name, bool optional) { struct mux_control **ptr, *mux; @@ -519,8 +553,8 @@ struct mux_control *devm_mux_control_get(struct device *dev, if (!ptr) return ERR_PTR(-ENOMEM); - mux = mux_control_get(dev, mux_name); - if (IS_ERR(mux)) { + mux = __mux_control_get(dev, mux_name, optional); + if (IS_ERR_OR_NULL(mux)) { devres_free(ptr); return mux; } @@ -530,8 +564,38 @@ struct mux_control *devm_mux_control_get(struct device *dev, return mux; } + +/** + * devm_mux_control_get() - Get the mux-control for a device, with resource + * management. + * @dev: The device that needs a mux-control. + * @mux_name: The name identifying the mux-control. + * + * Return: Pointer to the mux-control, or an ERR_PTR with a negative errno. + */ +struct mux_control * +devm_mux_control_get(struct device *dev, const char *mux_name) +{ + return __devm_mux_control_get(dev, mux_name, false); +} EXPORT_SYMBOL_GPL(devm_mux_control_get); +/** + * devm_mux_control_get_optional() - Get the optional mux-control for a device, + * with resource management. + * @dev: The device that needs a mux-control. + * @mux_name: The name identifying the mux-control. + * + * Return: NULL if no mux with the provided name is found, a pointer to + * the named mux-control or an ERR_PTR with a negative errno. + */ +struct mux_control * +devm_mux_control_get_optional(struct device *dev, const char *mux_name) +{ + return __devm_mux_control_get(dev, mux_name, true); +} +EXPORT_SYMBOL_GPL(devm_mux_control_get_optional); + /* * Using subsys_initcall instead of module_init here to try to ensure - for * the non-modular case - that the subsystem is initialized when mux consumers diff --git a/include/linux/mux/consumer.h b/include/linux/mux/consumer.h index 5fc6bb2fefad96a739fc6502ae49330a3d4991dc..b02ec71670f978e0ceee2e809a3e84fd751d8d40 100644 --- a/include/linux/mux/consumer.h +++ b/include/linux/mux/consumer.h @@ -23,9 +23,13 @@ int __must_check mux_control_try_select(struct mux_control *mux, int mux_control_deselect(struct mux_control *mux); 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_control *devm_mux_control_get_optional(struct device *dev, + const char *mux_name); #endif /* _LINUX_MUX_CONSUMER_H */