[PATCH v4 1/8] reset: modify the way reset lookup works for board files

Bartosz Golaszewski
2018-03-23T13:05:04Z

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

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 <bgolaszewski@baylibre.com>
---
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..f4a29c046995 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 -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
--
2.16.1