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Subject[PATCH v2 02/10] coresight: platform: Refactor graph endpoint parsing
Date
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 v1:
- Splitted from the of_node refcounting fix, part1
---
drivers/hwtracing/coresight/of_coresight.c | 129 +++++++++++++++++------------
1 file changed, 75 insertions(+), 54 deletions(-)

diff --git a/drivers/hwtracing/coresight/of_coresight.c b/drivers/hwtracing/coresight/of_coresight.c
index 6880bee..68faaf8 100644
--- a/drivers/hwtracing/coresight/of_coresight.c
+++ b/drivers/hwtracing/coresight/of_coresight.c
@@ -114,17 +114,69 @@ 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. Also
+ * updates *@i to point to the next index, when an entry is added.
+ *
+ * Returns :
+ * 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;
+ /* Move the index */
+ (*i)++;
+ } 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 +184,33 @@ 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 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, processing for as
+ * processing for output ports will deal with them.
+ */
+ if (of_find_property(ep, "slave-mode", NULL))
+ continue;
+
+ ret = of_coresight_parse_endpoint(dev, ep, pdata, &i);
if (ret)
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);
--
2.7.4
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