| Message ID | 20220303223351.141238-1-bjorn.andersson@linaro.org |
|---|---|
| State | Accepted |
| Commit | 7a20917d30fb627bebff6bacbe860ad4eb3a04d6 |
| Headers | show |
| Series | [v3,1/6] device property: Helper to match multiple connections | expand |
On Fri 04 Mar 06:54 CST 2022, Andy Shevchenko wrote: > On Thu, Mar 03, 2022 at 02:33:46PM -0800, Bjorn Andersson wrote: > > In some cases multiple connections with the same connection id > > needs to be resolved from a fwnode graph. > > > > One such example is when separate hardware is used for performing muxing > > and/or orientation switching of the SuperSpeed and SBU lines in a USB > > Type-C connector. In this case the connector needs to belong to a graph > > with multiple matching remote endpoints, and the Type-C controller needs > > to be able to resolve them both. > > > > Add a new API that allows this kind of lookup. > > ... > > > +static unsigned int fwnode_graph_devcon_matches(struct fwnode_handle *fwnode, > > + const char *con_id, void *data, > > + devcon_match_fn_t match, > > + void **matches, > > + unsigned int matches_len) > > +{ > > + struct fwnode_handle *node; > > + struct fwnode_handle *ep; > > + unsigned int count = 0; > > + void *ret; > > + > > + fwnode_graph_for_each_endpoint(fwnode, ep) { > > > + if (count >= matches_len && matches) { > > + fwnode_handle_put(ep); > > + return count; > > + } > > Wouldn't be the same as > > if (count >= matches_len) { This would cause the return value to be at most matches_len, seems relevant to ignore (or perhaps require it to be 0) when matches is NULL. But flipping the order of the expression seems better to me, now that this has been sitting for a while. > fwnode_handle_put(ep); > break; Right, this isn't an "early return", so nicer to have a single return at the bottom. > } > > ? > > > + node = fwnode_graph_get_remote_port_parent(ep); > > + if (!fwnode_device_is_available(node)) { > > + fwnode_handle_put(node); > > + continue; > > + } > > + > > + ret = match(node, con_id, data); > > + fwnode_handle_put(node); > > + if (ret) { > > + if (matches) > > + matches[count] = ret; > > + count++; > > + } > > + } > > + return count; > > +} > > ... > > > +static unsigned int fwnode_devcon_matches(struct fwnode_handle *fwnode, > > + const char *con_id, void *data, > > + devcon_match_fn_t match, > > + void **matches, > > + unsigned int matches_len) > > +{ > > + struct fwnode_handle *node; > > + unsigned int count = 0; > > + unsigned int i; > > + void *ret; > > + > > + for (i = 0; ; i++) { > > > + if (count >= matches_len && matches) > > + return count; > > Ditto. > > > + node = fwnode_find_reference(fwnode, con_id, i); > > + if (IS_ERR(node)) > > + break; > > + > > + ret = match(node, NULL, data); > > + fwnode_handle_put(node); > > + if (ret) { > > + if (matches) > > + matches[count] = ret; > > + count++; > > + } > > + } > > + > > + return count; > > +} > > ... > > > +int fwnode_connection_find_matches(struct fwnode_handle *fwnode, > > + const char *con_id, void *data, > > + devcon_match_fn_t match, > > + void **matches, unsigned int matches_len) > > +{ > > + unsigned int count_graph; > > + unsigned int count_ref; > > + > > + if (!fwnode || !match) > > + return -EINVAL; > > > + count_graph = fwnode_graph_devcon_matches(fwnode, con_id, data, match, > > + matches, matches_len); > > > + matches += count_graph; > > + matches_len -= count_graph; > > No, won't work when matches == NULL. > Sorry about that, you're obviously correct. > Also, matches_len is expected to be 0 in that case (or at least being ignored, > check with vsnprintf() behaviour in similar case). > > So, something like this, perhaps > > if (matches && matches_len) { > matches += count_graph; > matches_len -= count_graph; > } Seems reasonable. Thanks, Bjorn > > > + count_ref = fwnode_devcon_matches(fwnode, con_id, data, match, > > + matches, matches_len); > > + > > + return count_graph + count_ref; > > +} > > > -- > With Best Regards, > Andy Shevchenko > >
diff --git a/drivers/base/property.c b/drivers/base/property.c index c0e94cce9c29..5cda205136f6 100644 --- a/drivers/base/property.c +++ b/drivers/base/property.c @@ -1218,6 +1218,40 @@ fwnode_graph_devcon_match(struct fwnode_handle *fwnode, const char *con_id, return NULL; } +static unsigned int fwnode_graph_devcon_matches(struct fwnode_handle *fwnode, + const char *con_id, void *data, + devcon_match_fn_t match, + void **matches, + unsigned int matches_len) +{ + struct fwnode_handle *node; + struct fwnode_handle *ep; + unsigned int count = 0; + void *ret; + + fwnode_graph_for_each_endpoint(fwnode, ep) { + if (count >= matches_len && matches) { + fwnode_handle_put(ep); + return count; + } + + node = fwnode_graph_get_remote_port_parent(ep); + if (!fwnode_device_is_available(node)) { + fwnode_handle_put(node); + continue; + } + + ret = match(node, con_id, data); + fwnode_handle_put(node); + if (ret) { + if (matches) + matches[count] = ret; + count++; + } + } + return count; +} + static void * fwnode_devcon_match(struct fwnode_handle *fwnode, const char *con_id, void *data, devcon_match_fn_t match) @@ -1240,6 +1274,37 @@ fwnode_devcon_match(struct fwnode_handle *fwnode, const char *con_id, return NULL; } +static unsigned int fwnode_devcon_matches(struct fwnode_handle *fwnode, + const char *con_id, void *data, + devcon_match_fn_t match, + void **matches, + unsigned int matches_len) +{ + struct fwnode_handle *node; + unsigned int count = 0; + unsigned int i; + void *ret; + + for (i = 0; ; i++) { + if (count >= matches_len && matches) + return count; + + node = fwnode_find_reference(fwnode, con_id, i); + if (IS_ERR(node)) + break; + + ret = match(node, NULL, data); + fwnode_handle_put(node); + if (ret) { + if (matches) + matches[count] = ret; + count++; + } + } + + return count; +} + /** * fwnode_connection_find_match - Find connection from a device node * @fwnode: Device node with the connection @@ -1267,3 +1332,45 @@ void *fwnode_connection_find_match(struct fwnode_handle *fwnode, return fwnode_devcon_match(fwnode, con_id, data, match); } EXPORT_SYMBOL_GPL(fwnode_connection_find_match); + +/** + * fwnode_connection_find_matches - Find connections from a device node + * @fwnode: Device node with the connection + * @con_id: Identifier for the connection + * @data: Data for the match function + * @match: Function to check and convert the connection description + * @matches: Array of pointers to fill with matches + * @matches_len: Length of @matches + * + * Find up to @matches_len connections with unique identifier @con_id between + * @fwnode and other device nodes. @match will be used to convert the + * connection description to data the caller is expecting to be returned + * through the @matches array. + * If @matches is NULL @matches_len is ignored and the total number of resolved + * matches is returned. + * + * Return: Number of matches resolved, or negative errno. + */ +int fwnode_connection_find_matches(struct fwnode_handle *fwnode, + const char *con_id, void *data, + devcon_match_fn_t match, + void **matches, unsigned int matches_len) +{ + unsigned int count_graph; + unsigned int count_ref; + + if (!fwnode || !match) + return -EINVAL; + + count_graph = fwnode_graph_devcon_matches(fwnode, con_id, data, match, + matches, matches_len); + + matches += count_graph; + matches_len -= count_graph; + + count_ref = fwnode_devcon_matches(fwnode, con_id, data, match, + matches, matches_len); + + return count_graph + count_ref; +} +EXPORT_SYMBOL_GPL(fwnode_connection_find_matches); diff --git a/include/linux/property.h b/include/linux/property.h index 4cd4b326941f..de7ff336d2c8 100644 --- a/include/linux/property.h +++ b/include/linux/property.h @@ -447,6 +447,11 @@ static inline void *device_connection_find_match(struct device *dev, return fwnode_connection_find_match(dev_fwnode(dev), con_id, data, match); } +int fwnode_connection_find_matches(struct fwnode_handle *fwnode, + const char *con_id, void *data, + devcon_match_fn_t match, + void **matches, unsigned int matches_len); + /* -------------------------------------------------------------------------- */ /* Software fwnode support - when HW description is incomplete or missing */
In some cases multiple connections with the same connection id needs to be resolved from a fwnode graph. One such example is when separate hardware is used for performing muxing and/or orientation switching of the SuperSpeed and SBU lines in a USB Type-C connector. In this case the connector needs to belong to a graph with multiple matching remote endpoints, and the Type-C controller needs to be able to resolve them both. Add a new API that allows this kind of lookup. Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> --- Changes since v2: - Allow the caller of the new api to pass a matches of NULL, to count possible matches. I previously argued that this will cause memory leaks, but Andy pointed out that this depends on the caller and the match function. - Fixed spelling mistakes in commit message and kernel-doc. - Use two "count" variables to make the math clearer. Changes since v1: - Iterator in fwnode_devcon_matches() is now unsigned. - fwnode_handle_put() node for unavailable nodes. - Extended commit message on the subject of supporting dynamically sized "matches" array. drivers/base/property.c | 107 +++++++++++++++++++++++++++++++++++++++ include/linux/property.h | 5 ++ 2 files changed, 112 insertions(+)