From 87e3031b6fbd83ea83adf1bf9602bcce313ee787 Mon Sep 17 00:00:00 2001 From: Georgi Djakov Date: Wed, 16 Jan 2019 18:10:58 +0200 Subject: [PATCH] interconnect: Allow endpoints translation via DT Currently we support only platform data for specifying the interconnect endpoints. As now the endpoints are hard-coded into the consumer driver this may lead to complications when a single driver is used by multiple SoCs, which may have different interconnect topology. To avoid cluttering the consumer drivers, introduce a translation function to help us get the board specific interconnect data from device-tree. Reviewed-by: Evan Green Signed-off-by: Georgi Djakov Signed-off-by: Greg Kroah-Hartman --- drivers/interconnect/core.c | 149 ++++++++++++++++++++++++++ include/linux/interconnect-provider.h | 17 +++ include/linux/interconnect.h | 7 ++ 3 files changed, 173 insertions(+) diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c index 2b937b4f43c4..a8c2bd35197f 100644 --- a/drivers/interconnect/core.c +++ b/drivers/interconnect/core.c @@ -15,6 +15,7 @@ #include #include #include +#include #include static DEFINE_IDR(icc_idr); @@ -194,6 +195,152 @@ out: return ret; } +/* of_icc_xlate_onecell() - Translate function using a single index. + * @spec: OF phandle args to map into an interconnect node. + * @data: private data (pointer to struct icc_onecell_data) + * + * This is a generic translate function that can be used to model simple + * interconnect providers that have one device tree node and provide + * multiple interconnect nodes. A single cell is used as an index into + * an array of icc nodes specified in the icc_onecell_data struct when + * registering the provider. + */ +struct icc_node *of_icc_xlate_onecell(struct of_phandle_args *spec, + void *data) +{ + struct icc_onecell_data *icc_data = data; + unsigned int idx = spec->args[0]; + + if (idx >= icc_data->num_nodes) { + pr_err("%s: invalid index %u\n", __func__, idx); + return ERR_PTR(-EINVAL); + } + + return icc_data->nodes[idx]; +} +EXPORT_SYMBOL_GPL(of_icc_xlate_onecell); + +/** + * of_icc_get_from_provider() - Look-up interconnect node + * @spec: OF phandle args to use for look-up + * + * Looks for interconnect provider under the node specified by @spec and if + * found, uses xlate function of the provider to map phandle args to node. + * + * Returns a valid pointer to struct icc_node on success or ERR_PTR() + * on failure. + */ +static struct icc_node *of_icc_get_from_provider(struct of_phandle_args *spec) +{ + struct icc_node *node = ERR_PTR(-EPROBE_DEFER); + struct icc_provider *provider; + + if (!spec || spec->args_count != 1) + return ERR_PTR(-EINVAL); + + mutex_lock(&icc_lock); + list_for_each_entry(provider, &icc_providers, provider_list) { + if (provider->dev->of_node == spec->np) + node = provider->xlate(spec, provider->data); + if (!IS_ERR(node)) + break; + } + mutex_unlock(&icc_lock); + + return node; +} + +/** + * of_icc_get() - get a path handle from a DT node based on name + * @dev: device pointer for the consumer device + * @name: interconnect path name + * + * This function will search for a path between two endpoints and return an + * icc_path handle on success. Use icc_put() to release constraints when they + * are not needed anymore. + * If the interconnect API is disabled, NULL is returned and the consumer + * drivers will still build. Drivers are free to handle this specifically, + * but they don't have to. + * + * Return: icc_path pointer on success or ERR_PTR() on error. NULL is returned + * when the API is disabled or the "interconnects" DT property is missing. + */ +struct icc_path *of_icc_get(struct device *dev, const char *name) +{ + struct icc_path *path = ERR_PTR(-EPROBE_DEFER); + struct icc_node *src_node, *dst_node; + struct device_node *np = NULL; + struct of_phandle_args src_args, dst_args; + int idx = 0; + int ret; + + if (!dev || !dev->of_node) + return ERR_PTR(-ENODEV); + + np = dev->of_node; + + /* + * When the consumer DT node do not have "interconnects" property + * return a NULL path to skip setting constraints. + */ + if (!of_find_property(np, "interconnects", NULL)) + return NULL; + + /* + * We use a combination of phandle and specifier for endpoint. For now + * lets support only global ids and extend this in the future if needed + * without breaking DT compatibility. + */ + if (name) { + idx = of_property_match_string(np, "interconnect-names", name); + if (idx < 0) + return ERR_PTR(idx); + } + + ret = of_parse_phandle_with_args(np, "interconnects", + "#interconnect-cells", idx * 2, + &src_args); + if (ret) + return ERR_PTR(ret); + + of_node_put(src_args.np); + + ret = of_parse_phandle_with_args(np, "interconnects", + "#interconnect-cells", idx * 2 + 1, + &dst_args); + if (ret) + return ERR_PTR(ret); + + of_node_put(dst_args.np); + + src_node = of_icc_get_from_provider(&src_args); + + if (IS_ERR(src_node)) { + if (PTR_ERR(src_node) != -EPROBE_DEFER) + dev_err(dev, "error finding src node: %ld\n", + PTR_ERR(src_node)); + return ERR_CAST(src_node); + } + + dst_node = of_icc_get_from_provider(&dst_args); + + if (IS_ERR(dst_node)) { + if (PTR_ERR(dst_node) != -EPROBE_DEFER) + dev_err(dev, "error finding dst node: %ld\n", + PTR_ERR(dst_node)); + return ERR_CAST(dst_node); + } + + mutex_lock(&icc_lock); + path = path_find(dev, src_node, dst_node); + if (IS_ERR(path)) + dev_err(dev, "%s: invalid path=%ld\n", __func__, PTR_ERR(path)); + mutex_unlock(&icc_lock); + + return path; +} +EXPORT_SYMBOL_GPL(of_icc_get); + /** * icc_set_bw() - set bandwidth constraints on an interconnect path * @path: reference to the path returned by icc_get() @@ -519,6 +666,8 @@ int icc_provider_add(struct icc_provider *provider) { if (WARN_ON(!provider->set)) return -EINVAL; + if (WARN_ON(!provider->xlate)) + return -EINVAL; mutex_lock(&icc_lock); diff --git a/include/linux/interconnect-provider.h b/include/linux/interconnect-provider.h index 78208a754181..63caccadc2db 100644 --- a/include/linux/interconnect-provider.h +++ b/include/linux/interconnect-provider.h @@ -12,6 +12,21 @@ #define icc_units_to_bps(bw) ((bw) * 1000ULL) struct icc_node; +struct of_phandle_args; + +/** + * struct icc_onecell_data - driver data for onecell interconnect providers + * + * @num_nodes: number of nodes in this device + * @nodes: array of pointers to the nodes in this device + */ +struct icc_onecell_data { + unsigned int num_nodes; + struct icc_node *nodes[]; +}; + +struct icc_node *of_icc_xlate_onecell(struct of_phandle_args *spec, + void *data); /** * struct icc_provider - interconnect provider (controller) entity that might @@ -21,6 +36,7 @@ struct icc_node; * @nodes: internal list of the interconnect provider nodes * @set: pointer to device specific set operation function * @aggregate: pointer to device specific aggregate operation function + * @xlate: provider-specific callback for mapping nodes from phandle arguments * @dev: the device this interconnect provider belongs to * @users: count of active users * @data: pointer to private data @@ -31,6 +47,7 @@ struct icc_provider { int (*set)(struct icc_node *src, struct icc_node *dst); int (*aggregate)(struct icc_node *node, u32 avg_bw, u32 peak_bw, u32 *agg_avg, u32 *agg_peak); + struct icc_node* (*xlate)(struct of_phandle_args *spec, void *data); struct device *dev; int users; void *data; diff --git a/include/linux/interconnect.h b/include/linux/interconnect.h index c331afb3a2c8..dc25864755ba 100644 --- a/include/linux/interconnect.h +++ b/include/linux/interconnect.h @@ -27,6 +27,7 @@ struct device; struct icc_path *icc_get(struct device *dev, const int src_id, const int dst_id); +struct icc_path *of_icc_get(struct device *dev, const char *name); void icc_put(struct icc_path *path); int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw); @@ -38,6 +39,12 @@ static inline struct icc_path *icc_get(struct device *dev, const int src_id, return NULL; } +static inline struct icc_path *of_icc_get(struct device *dev, + const char *name) +{ + return NULL; +} + static inline void icc_put(struct icc_path *path) { } -- 2.30.2