diff options
Diffstat (limited to 'drivers/mux/core.c')
| -rw-r--r-- | drivers/mux/core.c | 194 |
1 files changed, 167 insertions, 27 deletions
diff --git a/drivers/mux/core.c b/drivers/mux/core.c index f09ee8782e3d..23538de2c91b 100644 --- a/drivers/mux/core.c +++ b/drivers/mux/core.c @@ -46,6 +46,16 @@ static const struct class mux_class = { .name = "mux", }; +/** + * struct devm_mux_state_state - Tracks managed resources for mux-state objects. + * @mstate: Pointer to a mux state. + * @exit: An optional callback to execute before free. + */ +struct devm_mux_state_state { + struct mux_state *mstate; + int (*exit)(struct mux_state *mstate); +}; + static DEFINE_IDA(mux_ida); static int __init mux_init(void) @@ -516,17 +526,19 @@ static struct mux_chip *of_find_mux_chip_by_node(struct device_node *np) return dev ? to_mux_chip(dev) : NULL; } -/* +/** * mux_get() - Get the mux-control for a device. * @dev: The device that needs a mux-control. * @mux_name: The name identifying the mux-control. * @state: Pointer to where the requested state is returned, or NULL when * the required multiplexer states are handled by other means. + * @optional: Whether to return NULL and silence errors when mux doesn't exist. * - * Return: A pointer to the mux-control, or an ERR_PTR with a negative errno. + * Return: Pointer to the mux-control on success, an ERR_PTR with a negative + * errno on error, or NULL if optional is true and mux doesn't exist. */ static struct mux_control *mux_get(struct device *dev, const char *mux_name, - unsigned int *state) + unsigned int *state, bool optional) { struct device_node *np = dev->of_node; struct of_phandle_args args; @@ -542,7 +554,9 @@ static struct mux_control *mux_get(struct device *dev, const char *mux_name, else index = of_property_match_string(np, "mux-control-names", mux_name); - if (index < 0) { + if (index < 0 && optional) { + return NULL; + } else if (index < 0) { dev_err(dev, "mux controller '%s' not found\n", mux_name); return ERR_PTR(index); @@ -558,8 +572,12 @@ static struct mux_control *mux_get(struct device *dev, const char *mux_name, "mux-controls", "#mux-control-cells", index, &args); if (ret) { + if (optional && ret == -ENOENT) + return NULL; + dev_err(dev, "%pOF: failed to get mux-%s %s(%i)\n", - np, state ? "state" : "control", mux_name ?: "", index); + np, state ? "state" : "control", + mux_name ?: "", index); return ERR_PTR(ret); } @@ -617,11 +635,30 @@ static struct mux_control *mux_get(struct device *dev, const char *mux_name, */ struct mux_control *mux_control_get(struct device *dev, const char *mux_name) { - return mux_get(dev, mux_name, NULL); + struct mux_control *mux = mux_get(dev, mux_name, NULL, false); + + if (!mux) + return ERR_PTR(-ENOENT); + + return mux; } 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: Pointer to the mux-control on success, an ERR_PTR with a negative + * errno on error, or NULL if mux doesn't exist. + */ +struct mux_control *mux_control_get_optional(struct device *dev, const char *mux_name) +{ + return mux_get(dev, mux_name, NULL, 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. * @@ -670,14 +707,16 @@ struct mux_control *devm_mux_control_get(struct device *dev, } EXPORT_SYMBOL_GPL(devm_mux_control_get); -/* +/** * mux_state_get() - Get the mux-state for a device. * @dev: The device that needs a mux-state. * @mux_name: The name identifying the mux-state. + * @optional: Whether to return NULL and silence errors when mux doesn't exist. * - * Return: A pointer to the mux-state, or an ERR_PTR with a negative errno. + * Return: Pointer to the mux-state on success, an ERR_PTR with a negative + * errno on error, or NULL if optional is true and mux doesn't exist. */ -static struct mux_state *mux_state_get(struct device *dev, const char *mux_name) +static struct mux_state *mux_state_get(struct device *dev, const char *mux_name, bool optional) { struct mux_state *mstate; @@ -685,12 +724,15 @@ static struct mux_state *mux_state_get(struct device *dev, const char *mux_name) if (!mstate) return ERR_PTR(-ENOMEM); - mstate->mux = mux_get(dev, mux_name, &mstate->state); + mstate->mux = mux_get(dev, mux_name, &mstate->state, optional); if (IS_ERR(mstate->mux)) { int err = PTR_ERR(mstate->mux); kfree(mstate); return ERR_PTR(err); + } else if (!mstate->mux) { + kfree(mstate); + return optional ? NULL : ERR_PTR(-ENOENT); } return mstate; @@ -710,9 +752,66 @@ static void mux_state_put(struct mux_state *mstate) static void devm_mux_state_release(struct device *dev, void *res) { - struct mux_state *mstate = *(struct mux_state **)res; + struct devm_mux_state_state *devm_state = res; + + if (devm_state->exit) + devm_state->exit(devm_state->mstate); + + mux_state_put(devm_state->mstate); +} + +/** + * __devm_mux_state_get() - Get the optional mux-state for a device, + * with resource management. + * @dev: The device that needs a mux-state. + * @mux_name: The name identifying the mux-state. + * @optional: Whether to return NULL and silence errors when mux doesn't exist. + * @init: Optional function pointer for mux-state object initialisation. + * @exit: Optional function pointer for mux-state object cleanup on release. + * + * Return: Pointer to the mux-state on success, an ERR_PTR with a negative + * errno on error, or NULL if optional is true and mux doesn't exist. + */ +static struct mux_state *__devm_mux_state_get(struct device *dev, const char *mux_name, + bool optional, + int (*init)(struct mux_state *mstate), + int (*exit)(struct mux_state *mstate)) +{ + struct devm_mux_state_state *devm_state; + struct mux_state *mstate; + int ret; + + mstate = mux_state_get(dev, mux_name, optional); + if (IS_ERR(mstate)) + return ERR_CAST(mstate); + else if (optional && !mstate) + return NULL; + else if (!mstate) + return ERR_PTR(-ENOENT); + + devm_state = devres_alloc(devm_mux_state_release, sizeof(*devm_state), GFP_KERNEL); + if (!devm_state) { + ret = -ENOMEM; + goto err_devres_alloc; + } + + if (init) { + ret = init(mstate); + if (ret) + goto err_mux_state_init; + } + + devm_state->mstate = mstate; + devm_state->exit = exit; + devres_add(dev, devm_state); + return mstate; + +err_mux_state_init: + devres_free(devm_state); +err_devres_alloc: mux_state_put(mstate); + return ERR_PTR(ret); } /** @@ -722,28 +821,69 @@ static void devm_mux_state_release(struct device *dev, void *res) * @mux_name: The name identifying the mux-control. * * Return: Pointer to the mux-state, or an ERR_PTR with a negative errno. + * + * The mux-state will automatically be freed on release. */ -struct mux_state *devm_mux_state_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 **ptr, *mstate; - - ptr = devres_alloc(devm_mux_state_release, sizeof(*ptr), GFP_KERNEL); - if (!ptr) - return ERR_PTR(-ENOMEM); + return __devm_mux_state_get(dev, mux_name, false, NULL, NULL); +} +EXPORT_SYMBOL_GPL(devm_mux_state_get); - mstate = mux_state_get(dev, mux_name); - if (IS_ERR(mstate)) { - devres_free(ptr); - return mstate; - } +/** + * devm_mux_state_get_optional() - Get the optional mux-state for a device, + * with resource management. + * @dev: The device that needs a mux-state. + * @mux_name: The name identifying the mux-state. + * + * Return: Pointer to the mux-state on success, an ERR_PTR with a negative + * errno on error, or NULL if mux doesn't exist. + * + * The mux-state will automatically be freed on release. + */ +struct mux_state *devm_mux_state_get_optional(struct device *dev, const char *mux_name) +{ + return __devm_mux_state_get(dev, mux_name, true, NULL, NULL); +} +EXPORT_SYMBOL_GPL(devm_mux_state_get_optional); - *ptr = mstate; - devres_add(dev, ptr); +/** + * devm_mux_state_get_selected() - Get the mux-state for a device, with + * resource management. + * @dev: The device that needs a mux-state. + * @mux_name: The name identifying the mux-state. + * + * Return: Pointer to the mux-state, or an ERR_PTR with a negative errno. + * + * The returned mux-state (if valid) is already selected. + * + * The mux-state will automatically be deselected and freed on release. + */ +struct mux_state *devm_mux_state_get_selected(struct device *dev, const char *mux_name) +{ + return __devm_mux_state_get(dev, mux_name, false, mux_state_select, mux_state_deselect); +} +EXPORT_SYMBOL_GPL(devm_mux_state_get_selected); - return mstate; +/** + * devm_mux_state_get_optional_selected() - Get the optional mux-state for + * a device, with resource management. + * @dev: The device that needs a mux-state. + * @mux_name: The name identifying the mux-state. + * + * Return: Pointer to the mux-state on success, an ERR_PTR with a negative + * errno on error, or NULL if mux doesn't exist. + * + * The returned mux-state (if valid) is already selected. + * + * The mux-state will automatically be deselected and freed on release. + */ +struct mux_state *devm_mux_state_get_optional_selected(struct device *dev, + const char *mux_name) +{ + return __devm_mux_state_get(dev, mux_name, true, mux_state_select, mux_state_deselect); } -EXPORT_SYMBOL_GPL(devm_mux_state_get); +EXPORT_SYMBOL_GPL(devm_mux_state_get_optional_selected); /* * Using subsys_initcall instead of module_init here to try to ensure - for |