Refactor the of graph endpoint parsing code, to make the error handling easier.
Cc: Mathieu Poirier mathieu.poirier@linaro.org Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com --- Changes since v2: - Use return code to indicate a record was updated than moving the index from the helper function --- drivers/hwtracing/coresight/of_coresight.c | 138 +++++++++++++++++------------ 1 file changed, 83 insertions(+), 55 deletions(-)
diff --git a/drivers/hwtracing/coresight/of_coresight.c b/drivers/hwtracing/coresight/of_coresight.c index 6880bee..70205f3 100644 --- a/drivers/hwtracing/coresight/of_coresight.c +++ b/drivers/hwtracing/coresight/of_coresight.c @@ -114,17 +114,70 @@ int of_coresight_get_cpu(const struct device_node *node) } EXPORT_SYMBOL_GPL(of_coresight_get_cpu);
+/* + * of_coresight_parse_endpoint : Parse the given output endpoint @ep + * and fill the connection information in @pdata[@i]. + * + * Parses the local port, remote device name and the remote port. + * + * Returns : + * 1 - If the parsing is successful and a connection record + * was created for an output connection. + * 0 - If the parsing completed without any fatal errors. + * -Errno - Fatal error, abort the scanning. + */ +static int of_coresight_parse_endpoint(struct device *dev, + struct device_node *ep, + struct coresight_platform_data *pdata, + int i) +{ + int ret = 0; + struct of_endpoint endpoint, rendpoint; + struct device_node *rparent = NULL; + struct device_node *rport = NULL; + struct device *rdev = NULL; + + do { + /* Parse the local port details */ + if (of_graph_parse_endpoint(ep, &endpoint)) + break; + /* + * Get a handle on the remote port and parent + * attached to it. + */ + rparent = of_graph_get_remote_port_parent(ep); + if (!rparent) + break; + rport = of_graph_get_remote_port(ep); + if (!rport) + break; + if (of_graph_parse_endpoint(rport, &rendpoint)) + break; + + /* If the remote device is not available, defer probing */ + rdev = of_coresight_get_endpoint_device(rparent); + if (!rdev) { + ret = -EPROBE_DEFER; + break; + } + + pdata->outports[i] = endpoint.port; + pdata->child_names[i] = dev_name(rdev); + pdata->child_ports[i] = rendpoint.id; + /* Connection record updated */ + ret = 1; + } while (0); + + return ret; +} + struct coresight_platform_data * of_get_coresight_platform_data(struct device *dev, const struct device_node *node) { int i = 0, ret = 0; struct coresight_platform_data *pdata; - struct of_endpoint endpoint, rendpoint; - struct device *rdev; struct device_node *ep = NULL; - struct device_node *rparent = NULL; - struct device_node *rport = NULL;
pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); if (!pdata) @@ -132,64 +185,39 @@ of_get_coresight_platform_data(struct device *dev,
/* Use device name as sysfs handle */ pdata->name = dev_name(dev); + pdata->cpu = of_coresight_get_cpu(node);
/* Get the number of input and output port for this component */ of_coresight_get_ports(node, &pdata->nr_inport, &pdata->nr_outport);
- if (pdata->nr_outport) { - ret = of_coresight_alloc_memory(dev, pdata); - if (ret) + /* If there are no output connections, we are done */ + if (!pdata->nr_outport) + return pdata; + + ret = of_coresight_alloc_memory(dev, pdata); + if (ret) + return ERR_PTR(ret); + + /* Iterate through each port to discover topology */ + while ((ep = of_graph_get_next_endpoint(node, ep))) { + /* + * No need to deal with input ports, as processing the + * output ports connected to them will process the details. + */ + if (of_find_property(ep, "slave-mode", NULL)) + continue; + + ret = of_coresight_parse_endpoint(dev, ep, pdata, i); + switch (ret) { + case 1: + i++; /* Fall through */ + case 0: + break; + default: return ERR_PTR(ret); - - /* Iterate through each port to discover topology */ - do { - /* Get a handle on a port */ - ep = of_graph_get_next_endpoint(node, ep); - if (!ep) - break; - - /* - * No need to deal with input ports, processing for as - * processing for output ports will deal with them. - */ - if (of_find_property(ep, "slave-mode", NULL)) - continue; - - /* Get a handle on the local endpoint */ - ret = of_graph_parse_endpoint(ep, &endpoint); - - if (ret) - continue; - - /* The local out port number */ - pdata->outports[i] = endpoint.port; - - /* - * Get a handle on the remote port and parent - * attached to it. - */ - rparent = of_graph_get_remote_port_parent(ep); - rport = of_graph_get_remote_port(ep); - - if (!rparent || !rport) - continue; - - if (of_graph_parse_endpoint(rport, &rendpoint)) - continue; - - rdev = of_coresight_get_endpoint_device(rparent); - if (!rdev) - return ERR_PTR(-EPROBE_DEFER); - - pdata->child_names[i] = dev_name(rdev); - pdata->child_ports[i] = rendpoint.id; - - i++; - } while (ep); + } }
- pdata->cpu = of_coresight_get_cpu(node); - return pdata; } EXPORT_SYMBOL_GPL(of_get_coresight_platform_data);