From 6691dffab0ab6301bb7b489b1dcf9f5efdef202f Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Wed, 28 Feb 2018 14:08:57 +0100 Subject: reset: add support for non-DT systems The reset framework only supports device-tree. There are some platforms however, which need to use it even in legacy, board-file based mode. An example of such architecture is the DaVinci family of SoCs which supports both device tree and legacy boot modes and we don't want to introduce any regressions. We're currently working on converting the platform from its hand-crafted clock API to using the common clock framework. Part of the overhaul will be representing the chip's power sleep controller's reset lines using the reset framework. This changeset extends the core reset code with a new reset lookup entry structure. It contains data allowing the reset core to associate reset lines with devices by comparing the dev_id and con_id strings. It also provides a function allowing drivers to register lookup entries with the framework. The new lookup function is only called as a fallback in case the of_node field is NULL and doesn't change anything for current users. Tested with a dummy reset driver with several lookup entries. An example lookup table registration from a driver can be found below: static struct reset_control_lookup foobar_reset_lookup[] = { RESET_LOOKUP("foo.0", "foo", 15), RESET_LOOKUP("bar.0", NULL, 5), }; foobar_probe() { ... reset_controller_add_lookup(&rcdev, foobar_reset_lookup, ARRAY_SIZE(foobar_reset_lookup)); ... } Cc: Sekhar Nori Cc: Kevin Hilman Cc: David Lechner Signed-off-by: Bartosz Golaszewski Signed-off-by: Philipp Zabel --- drivers/reset/core.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 71 insertions(+), 1 deletion(-) (limited to 'drivers/reset') diff --git a/drivers/reset/core.c b/drivers/reset/core.c index da4292e9de97..06fa4907afc4 100644 --- a/drivers/reset/core.c +++ b/drivers/reset/core.c @@ -23,6 +23,9 @@ static DEFINE_MUTEX(reset_list_mutex); static LIST_HEAD(reset_controller_list); +static DEFINE_MUTEX(reset_lookup_mutex); +static LIST_HEAD(reset_lookup_list); + /** * struct reset_control - a reset control * @rcdev: a pointer to the reset controller device @@ -148,6 +151,36 @@ int devm_reset_controller_register(struct device *dev, } EXPORT_SYMBOL_GPL(devm_reset_controller_register); +/** + * reset_controller_add_lookup - register a set of lookup entries + * @rcdev: initialized reset controller device owning the reset line + * @lookup: array of reset lookup entries + * @num_entries: number of entries in the lookup array + */ +void reset_controller_add_lookup(struct reset_controller_dev *rcdev, + struct reset_control_lookup *lookup, + unsigned int num_entries) +{ + struct reset_control_lookup *entry; + unsigned int i; + + mutex_lock(&reset_lookup_mutex); + for (i = 0; i < num_entries; i++) { + entry = &lookup[i]; + + if (!entry->dev_id) { + pr_warn("%s(): reset lookup entry has no dev_id, skipping\n", + __func__); + continue; + } + + entry->rcdev = rcdev; + list_add_tail(&entry->list, &reset_lookup_list); + } + mutex_unlock(&reset_lookup_mutex); +} +EXPORT_SYMBOL_GPL(reset_controller_add_lookup); + static inline struct reset_control_array * rstc_to_array(struct reset_control *rstc) { return container_of(rstc, struct reset_control_array, base); @@ -493,6 +526,43 @@ struct reset_control *__of_reset_control_get(struct device_node *node, } EXPORT_SYMBOL_GPL(__of_reset_control_get); +static struct reset_control * +__reset_control_get_from_lookup(struct device *dev, const char *con_id, + bool shared, bool optional) +{ + const struct reset_control_lookup *lookup; + const char *dev_id = dev_name(dev); + struct reset_control *rstc = NULL; + + if (!dev) + return ERR_PTR(-EINVAL); + + mutex_lock(&reset_lookup_mutex); + + list_for_each_entry(lookup, &reset_lookup_list, list) { + if (strcmp(lookup->dev_id, dev_id)) + continue; + + if ((!con_id && !lookup->con_id) || + ((con_id && lookup->con_id) && + !strcmp(con_id, lookup->con_id))) { + mutex_lock(&reset_list_mutex); + rstc = __reset_control_get_internal(lookup->rcdev, + lookup->index, + shared); + mutex_unlock(&reset_list_mutex); + break; + } + } + + mutex_unlock(&reset_lookup_mutex); + + if (!rstc) + return optional ? NULL : ERR_PTR(-ENOENT); + + return rstc; +} + struct reset_control *__reset_control_get(struct device *dev, const char *id, int index, bool shared, bool optional) { @@ -500,7 +570,7 @@ struct reset_control *__reset_control_get(struct device *dev, const char *id, return __of_reset_control_get(dev->of_node, id, index, shared, optional); - return optional ? NULL : ERR_PTR(-EINVAL); + return __reset_control_get_from_lookup(dev, id, shared, optional); } EXPORT_SYMBOL_GPL(__reset_control_get); -- cgit v1.2.3