Commit 87e3031b authored by Georgi Djakov's avatar Georgi Djakov Committed by Greg Kroah-Hartman

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: default avatarEvan Green <evgreen@chromium.org>
Signed-off-by: default avatarGeorgi Djakov <georgi.djakov@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 06b3773b
......@@ -15,6 +15,7 @@
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/overflow.h>
static DEFINE_IDR(icc_idr);
......@@ -194,6 +195,152 @@ static int apply_constraints(struct icc_path *path)
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);
......
......@@ -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;
......
......@@ -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)
{
}
......
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