On non DT platforms we cannot get the mux_chip by pnode. Other subsystems (regulator, clock, pwm) have the same problem and solve this by allowing platform / board-setup code to add entries to a lookup table and then use this table to look things up.
This commit adds support for getting a mux controller on a non DT platform following this pattern. It is based on a simplified version of the pwm subsys lookup code, the dev_id and mux_name parts of a lookup table entry are mandatory in the mux-core implementation. Signed-off-by: Hans de Goede <hdego...@redhat.com> --- Changes in v2: -Fixup some kerneldoc comments, add kerneldoc comment to structs -Minor code-style tweaks --- drivers/mux/core.c | 93 +++++++++++++++++++++++++++++++++++++++++++- include/linux/mux/consumer.h | 19 +++++++++ 2 files changed, 111 insertions(+), 1 deletion(-) diff --git a/drivers/mux/core.c b/drivers/mux/core.c index 99d29f982c0e..e25bb7ab03ce 100644 --- a/drivers/mux/core.c +++ b/drivers/mux/core.c @@ -24,6 +24,9 @@ #include <linux/of_platform.h> #include <linux/slab.h> +static DEFINE_MUTEX(mux_lookup_lock); +static LIST_HEAD(mux_lookup_list); + /* * The idle-as-is "state" is not an actual state that may be selected, it * only implies that the state should not be changed. So, use that state @@ -408,6 +411,23 @@ int mux_control_deselect(struct mux_control *mux) } EXPORT_SYMBOL_GPL(mux_control_deselect); +static int parent_name_match(struct device *dev, const void *data) +{ + const char *parent_name = dev_name(dev->parent); + const char *name = data; + + return strcmp(parent_name, name) == 0; +} + +static struct mux_chip *mux_chip_get_by_name(const char *name) +{ + struct device *dev; + + dev = class_find_device(&mux_class, NULL, name, parent_name_match); + + return dev ? to_mux_chip(dev) : NULL; +} + static int of_dev_node_match(struct device *dev, const void *data) { return dev->of_node == data; @@ -480,6 +500,38 @@ static struct mux_control *of_mux_control_get(struct device *dev, } /** + * mux_add_table() - Register consumer to mux-controller mappings + * @table: array of mappings to register + * @num: number of mappings in table + */ +void mux_add_table(struct mux_lookup *table, size_t num) +{ + mutex_lock(&mux_lookup_lock); + + for (; num--; table++) + list_add_tail(&table->list, &mux_lookup_list); + + mutex_unlock(&mux_lookup_lock); +} +EXPORT_SYMBOL_GPL(mux_add_table); + +/** + * mux_remove_table() - Unregister consumer to mux-controller mappings + * @table: array of mappings to unregister + * @num: number of mappings in table + */ +void mux_remove_table(struct mux_lookup *table, size_t num) +{ + mutex_lock(&mux_lookup_lock); + + for (; num--; table++) + list_del(&table->list); + + mutex_unlock(&mux_lookup_lock); +} +EXPORT_SYMBOL_GPL(mux_remove_table); + +/** * 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. @@ -488,11 +540,50 @@ static struct mux_control *of_mux_control_get(struct device *dev, */ struct mux_control *mux_control_get(struct device *dev, const char *mux_name) { + struct mux_lookup *m, *chosen = NULL; + const char *dev_id = dev_name(dev); + struct mux_chip *mux_chip; + /* look up via DT first */ if (IS_ENABLED(CONFIG_OF) && dev->of_node) return of_mux_control_get(dev, mux_name); - return ERR_PTR(-ENODEV); + /* + * For non DT we look up the provider in the static table typically + * provided by board setup code. + * + * If a match is found, the provider mux chip is looked up by name + * and a mux-control is requested using the table provided index. + */ + mutex_lock(&mux_lookup_lock); + list_for_each_entry(m, &mux_lookup_list, list) { + if (WARN_ON(!m->dev_id || !m->mux_name || !m->provider)) + continue; + + if (!strcmp(m->dev_id, dev_id) && + !strcmp(m->mux_name, mux_name)) + { + chosen = m; + break; + } + } + mutex_unlock(&mux_lookup_lock); + + if (!chosen) + return ERR_PTR(-ENODEV); + + mux_chip = mux_chip_get_by_name(chosen->provider); + if (!mux_chip) + return ERR_PTR(-EPROBE_DEFER); + + if (chosen->index >= mux_chip->controllers) { + dev_err(dev, "Mux lookup table index out of bounds %u >= %u\n", + chosen->index, mux_chip->controllers); + put_device(&mux_chip->dev); + return ERR_PTR(-EINVAL); + } + + return &mux_chip->mux[chosen->index]; } EXPORT_SYMBOL_GPL(mux_control_get); diff --git a/include/linux/mux/consumer.h b/include/linux/mux/consumer.h index ea96d4c82be7..62a8ec6171c9 100644 --- a/include/linux/mux/consumer.h +++ b/include/linux/mux/consumer.h @@ -18,6 +18,25 @@ struct device; struct mux_control; +/** + * struct mux_lookup - Mux consumer to mux-controller lookup table entry + * @list: List head, internal use only. + * @provider: dev_name() of the mux-chip's parent-dev. + * @index: mux-controller's index in the mux-chip's mux array + * @dev_id: dev_name() of the consumer to map to this controller + * @mux_name name the consumer passes to mux_control_get + */ +struct mux_lookup { + struct list_head list; + const char *provider; + unsigned int index; + const char *dev_id; + const char *mux_name; +}; + +void mux_add_table(struct mux_lookup *table, size_t num); +void mux_remove_table(struct mux_lookup *table, size_t num); + unsigned int mux_control_states(struct mux_control *mux); int __must_check mux_control_select(struct mux_control *mux, unsigned int state); -- 2.13.5 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html