From 6691dffab0ab6301bb7b489b1dcf9f5efdef202f Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Wed, 28 Feb 2018 14:08:57 +0100 Subject: [PATCH 1/2] 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 +++++++++++++++++++++++++++++++- include/linux/reset-controller.h | 28 +++++++++++++ 2 files changed, 99 insertions(+), 1 deletion(-) 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); diff --git a/include/linux/reset-controller.h b/include/linux/reset-controller.h index adb88f8cefbc..25698f6c1fae 100644 --- a/include/linux/reset-controller.h +++ b/include/linux/reset-controller.h @@ -26,6 +26,30 @@ struct module; struct device_node; struct of_phandle_args; +/** + * struct reset_control_lookup - represents a single lookup entry + * + * @list: internal list of all reset lookup entries + * @rcdev: reset controller device controlling this reset line + * @index: ID of the reset controller in the reset controller device + * @dev_id: name of the device associated with this reset line + * @con_id name of the reset line (can be NULL) + */ +struct reset_control_lookup { + struct list_head list; + struct reset_controller_dev *rcdev; + unsigned int index; + const char *dev_id; + const char *con_id; +}; + +#define RESET_LOOKUP(_dev_id, _con_id, _index) \ + { \ + .dev_id = _dev_id, \ + .con_id = _con_id, \ + .index = _index, \ + } + /** * struct reset_controller_dev - reset controller entity that might * provide multiple reset controls @@ -58,4 +82,8 @@ struct device; int devm_reset_controller_register(struct device *dev, struct reset_controller_dev *rcdev); +void reset_controller_add_lookup(struct reset_controller_dev *rcdev, + struct reset_control_lookup *lookup, + unsigned int num_entries); + #endif From e2749bb998701e21cdb8b34486b82fc1c051ab41 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Fri, 23 Mar 2018 14:04:48 +0100 Subject: [PATCH 2/2] reset: modify the way reset lookup works for board files Commit 7af1bb19f1d7 ("reset: add support for non-DT systems") introduced reset control lookup mechanism for boards that still use board files. The routine used to register lookup entries takes the corresponding reset_controlled_dev structure as argument. It's been determined however that for the first user of this new interface - davinci psc driver - it will be easier to register the lookup entries using the reset controller device name. This patch changes the way lookup entries are added. Signed-off-by: Bartosz Golaszewski [p.zabel@pengutronix.de: added missing ERR_PTR] Signed-off-by: Philipp Zabel --- drivers/reset/core.c | 38 ++++++++++++++++++++++++++------ include/linux/reset-controller.h | 14 +++++++----- 2 files changed, 39 insertions(+), 13 deletions(-) diff --git a/drivers/reset/core.c b/drivers/reset/core.c index 06fa4907afc4..6488292e129c 100644 --- a/drivers/reset/core.c +++ b/drivers/reset/core.c @@ -153,12 +153,10 @@ 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, +void reset_controller_add_lookup(struct reset_control_lookup *lookup, unsigned int num_entries) { struct reset_control_lookup *entry; @@ -168,13 +166,12 @@ void reset_controller_add_lookup(struct reset_controller_dev *rcdev, 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", + if (!entry->dev_id || !entry->provider) { + pr_warn("%s(): reset lookup entry badly specified, skipping\n", __func__); continue; } - entry->rcdev = rcdev; list_add_tail(&entry->list, &reset_lookup_list); } mutex_unlock(&reset_lookup_mutex); @@ -526,11 +523,30 @@ struct reset_control *__of_reset_control_get(struct device_node *node, } EXPORT_SYMBOL_GPL(__of_reset_control_get); +static struct reset_controller_dev * +__reset_controller_by_name(const char *name) +{ + struct reset_controller_dev *rcdev; + + lockdep_assert_held(&reset_list_mutex); + + list_for_each_entry(rcdev, &reset_controller_list, list) { + if (!rcdev->dev) + continue; + + if (!strcmp(name, dev_name(rcdev->dev))) + return rcdev; + } + + return NULL; +} + 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; + struct reset_controller_dev *rcdev; const char *dev_id = dev_name(dev); struct reset_control *rstc = NULL; @@ -547,7 +563,15 @@ __reset_control_get_from_lookup(struct device *dev, const char *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, + rcdev = __reset_controller_by_name(lookup->provider); + if (!rcdev) { + mutex_unlock(&reset_list_mutex); + mutex_unlock(&reset_lookup_mutex); + /* Reset provider may not be ready yet. */ + return ERR_PTR(-EPROBE_DEFER); + } + + rstc = __reset_control_get_internal(rcdev, lookup->index, shared); mutex_unlock(&reset_list_mutex); diff --git a/include/linux/reset-controller.h b/include/linux/reset-controller.h index 25698f6c1fae..9326d671b6e6 100644 --- a/include/linux/reset-controller.h +++ b/include/linux/reset-controller.h @@ -30,24 +30,25 @@ struct of_phandle_args; * struct reset_control_lookup - represents a single lookup entry * * @list: internal list of all reset lookup entries - * @rcdev: reset controller device controlling this reset line + * @provider: name of the reset controller device controlling this reset line * @index: ID of the reset controller in the reset controller device * @dev_id: name of the device associated with this reset line * @con_id name of the reset line (can be NULL) */ struct reset_control_lookup { struct list_head list; - struct reset_controller_dev *rcdev; + const char *provider; unsigned int index; const char *dev_id; const char *con_id; }; -#define RESET_LOOKUP(_dev_id, _con_id, _index) \ +#define RESET_LOOKUP(_provider, _index, _dev_id, _con_id) \ { \ + .provider = _provider, \ + .index = _index, \ .dev_id = _dev_id, \ .con_id = _con_id, \ - .index = _index, \ } /** @@ -57,6 +58,7 @@ struct reset_control_lookup { * @owner: kernel module of the reset controller driver * @list: internal list of reset controller devices * @reset_control_head: head of internal list of requested reset controls + * @dev: corresponding driver model device struct * @of_node: corresponding device tree node as phandle target * @of_reset_n_cells: number of cells in reset line specifiers * @of_xlate: translation function to translate from specifier as found in the @@ -68,6 +70,7 @@ struct reset_controller_dev { struct module *owner; struct list_head list; struct list_head reset_control_head; + struct device *dev; struct device_node *of_node; int of_reset_n_cells; int (*of_xlate)(struct reset_controller_dev *rcdev, @@ -82,8 +85,7 @@ struct device; int devm_reset_controller_register(struct device *dev, struct reset_controller_dev *rcdev); -void reset_controller_add_lookup(struct reset_controller_dev *rcdev, - struct reset_control_lookup *lookup, +void reset_controller_add_lookup(struct reset_control_lookup *lookup, unsigned int num_entries); #endif