snip...

quoted

+static void of_coresight_get_ports(struct device_node *node,
+                                  int *nr_inports, int *nr_outports)
+{
+       struct device_node *ep = NULL;
+       int in = 0, out = 0;
+
+       do {
+               ep = of_get_coresight_endpoint(node, ep);

Does for_each_child_of_node not work here?

Using for_each_child_of_node yields the first child of that node,
which may or may not be "ports" or "port".  By using
of_get_coresight_endpoint we let of_graph_get_next_endpoint to deal
with that hierarchy.  Moreover the latter will also deal with the
hierarchy of port under ports, something that would need to be
duplicated if for_each_child_of_node was used.

Get back to me if you disagree.

quoted

+               if (!ep)
+                       break;
+               of_coresight_is_input_port(ep) ? in++ : out++;
+
+       } while (ep);
+
+       *nr_inports = in;
+       *nr_outports = out;
+}
+
+static int of_coresight_alloc_memory(struct device *dev,
+                       struct coresight_platform_data *pdata)
+{
+       /* list of output port on this component */
+       pdata->outports = devm_kzalloc(dev, pdata->nr_outports *
+                                      sizeof(*pdata->outports),
+                                      GFP_KERNEL);
+       if (!pdata->outports)
+               return -ENOMEM;
+
+
+       /* children connected to this component via @outport */
+       pdata->child_ids = devm_kzalloc(dev, pdata->nr_outports *
+                                       sizeof(*pdata->child_ids),
+                                       GFP_KERNEL);
+       if (!pdata->child_ids)
+               return -ENOMEM;
+
+       /* port number on the child this component is connected to */
+       pdata->child_ports = devm_kzalloc(dev, pdata->nr_outports *
+                                         sizeof(*pdata->child_ports),
+                                         GFP_KERNEL);
+       if (!pdata->child_ports)
+               return -ENOMEM;
+
+       return 0;
+}
+
+struct coresight_platform_data *of_get_coresight_platform_data(
+                               struct device *dev, struct device_node *node)
+{
+       u32 id;
+       int i = 0, ret = 0;
+       struct device_node *cpu;
+       struct coresight_platform_data *pdata;
+       struct of_endpoint endpoint, rendpoint;
+       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)
+               return ERR_PTR(-ENOMEM);
+
+       /* use the base address as id */
+       id = of_get_coresight_id(node);
+       if (id == 0)
+               return  ERR_PTR(-EINVAL);
+
+       pdata->id = id;
+
+       /* use device name as debugfs handle */
+       pdata->name = dev_name(dev);
+
+       /* get the number of input and output port for this component */
+       of_coresight_get_ports(node, &pdata->nr_inports, &pdata->nr_outports);
+
+       if (pdata->nr_outports) {
+               ret = of_coresight_alloc_memory(dev, pdata);
+               if (ret)
+                       return ERR_PTR(-ENOMEM);
+
+               /* iterate through each port to discover topology */
+               do {
+                       /* get a handle on a port */
+                       ep = of_get_coresight_endpoint(node, ep);
+                       if (!ep)
+                               break;

for_each_child_of_node

Same as above.

quoted

+
+                       /* no need to deal with input ports, processing for as
+                        * processing for output ports will deal with them.
+                        */
+                       if (of_coresight_is_input_port(ep))
+                               continue;
+
+                       /* get a handle on the local endpoint */
+                       ret = of_graph_parse_endpoint(ep, &endpoint);
+
+                       if (!ret) {

You can save some indentation with:

if (ret)
 continue;

quoted

+                               /* the local out port number */
+                               *(u32 *)&pdata->outports[i] = endpoint.id;

Can't you avoid this casting?

quoted

+
+                               /* get a handle 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;
+
+                               *(u32 *)&pdata->child_ids[i] =
+                                       of_get_coresight_id(rparent);
+                               *(u32 *)&pdata->child_ports[i] = rendpoint.id;

and these?

quoted

+
+                               i++;
+                       }
+
+               } while (ep);
+       }
+
+       pdata->default_sink = of_property_read_bool(node,
+                                                   "coresight-default-sink");
+
+       /* affinity defaults to CPU0 */
+       pdata->cpu = 0;
+       cpu = of_parse_phandle(node, "cpu", 0);
+       if (cpu) {
+               const u32 *mpidr;
+               int len, index;
+
+               mpidr = of_get_property(cpu, "reg", &len);
+               if (mpidr && len == 4) {
+                       index = get_logical_index(be32_to_cpup(mpidr));

Don't we have some helper for translating a cpu phandle to logical index?

I haven't found one - the same trickery can be found in [1] [2]. Even
the very recent 64 bit implementation doesn't use a helper function
[3].  The opposite direction i.e, going from a logical CPU to a
device_node, has a helper function.  If you have something on the top
of your mind I'd like to know.

[1]. arch/arm/kernel/devtree.c, (arm_dt_init_cpu_maps)
[2]. arch/powerpc/kernel/smp.c, (cpu_to_corei_id)
[3]. arch/arm64/kernel/smp.c, (smp_init_cpus)

quoted

+                       if (index != -EINVAL)
+                               pdata->cpu = index;
+               }
+       }
+
+       return pdata;
+}
+EXPORT_SYMBOL_GPL(of_get_coresight_platform_data);

diff --git a/include/linux/amba/bus.h b/include/linux/amba/bus.h
index fdd7e1b..cdddabe 100644
--- a/include/linux/amba/bus.h
+++ b/include/linux/amba/bus.h

@@ -23,6 +23,7 @@

 #define AMBA_NR_IRQS   9
 #define AMBA_CID       0xb105f00d
+#define CORESIGHT_CID  0xb105900d

 struct clk;

diff --git a/include/linux/coresight.h b/include/linux/coresight.h
new file mode 100644
index 0000000..a19420e
--- /dev/null
+++ b/include/linux/coresight.h

@@ -0,0 +1,190 @@
+/* Copyright (c) 2012, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _LINUX_CORESIGHT_H
+#define _LINUX_CORESIGHT_H
+
+#include <linux/device.h>
+
+/* Peripheral id registers (0xFD0-0xFEC) */
+#define CORESIGHT_PERIPHIDR4   (0xFD0)
+#define CORESIGHT_PERIPHIDR5   (0xFD4)
+#define CORESIGHT_PERIPHIDR6   (0xFD8)
+#define CORESIGHT_PERIPHIDR7   (0xFDC)
+#define CORESIGHT_PERIPHIDR0   (0xFE0)
+#define CORESIGHT_PERIPHIDR1   (0xFE4)
+#define CORESIGHT_PERIPHIDR2   (0xFE8)
+#define CORESIGHT_PERIPHIDR3   (0xFEC)
+/* Component id registers (0xFF0-0xFFC) */
+#define CORESIGHT_COMPIDR0     (0xFF0)
+#define CORESIGHT_COMPIDR1     (0xFF4)
+#define CORESIGHT_COMPIDR2     (0xFF8)
+#define CORESIGHT_COMPIDR3     (0xFFC)
+
+#define ETM_ARCH_V3_3          (0x23)
+#define ETM_ARCH_V3_5          (0x25)
+#define PFT_ARCH_V1_1          (0x31)
+
+#define CORESIGHT_UNLOCK       (0xC5ACCE55)

Parentheses are not necessary.

quoted

+enum coresight_clk_rate {
+       CORESIGHT_CLK_RATE_OFF,
+       CORESIGHT_CLK_RATE_TRACE,
+       CORESIGHT_CLK_RATE_HSTRACE,
+};
+
+enum coresight_dev_type {
+       CORESIGHT_DEV_TYPE_NONE,
+       CORESIGHT_DEV_TYPE_SINK,
+       CORESIGHT_DEV_TYPE_LINK,
+       CORESIGHT_DEV_TYPE_LINKSINK,
+       CORESIGHT_DEV_TYPE_SOURCE,
+};
+
+enum coresight_dev_subtype_sink {
+       CORESIGHT_DEV_SUBTYPE_SINK_NONE,
+       CORESIGHT_DEV_SUBTYPE_SINK_PORT,
+       CORESIGHT_DEV_SUBTYPE_SINK_BUFFER,
+};
+
+enum coresight_dev_subtype_link {
+       CORESIGHT_DEV_SUBTYPE_LINK_NONE,
+       CORESIGHT_DEV_SUBTYPE_LINK_MERG,
+       CORESIGHT_DEV_SUBTYPE_LINK_SPLIT,
+       CORESIGHT_DEV_SUBTYPE_LINK_FIFO,
+};
+
+enum coresight_dev_subtype_source {
+       CORESIGHT_DEV_SUBTYPE_SOURCE_NONE,
+       CORESIGHT_DEV_SUBTYPE_SOURCE_PROC,
+       CORESIGHT_DEV_SUBTYPE_SOURCE_BUS,
+       CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE,
+};
+
+struct coresight_ops_entry {
+       const char *name;
+       umode_t mode;
+       const struct file_operations *ops;
+};
+
+struct coresight_dev_subtype {
+       enum coresight_dev_subtype_sink sink_subtype;
+       enum coresight_dev_subtype_link link_subtype;
+       enum coresight_dev_subtype_source source_subtype;
+};
+
+struct coresight_platform_data {
+       int id;
+       int cpu;
+       const char *name;
+       int nr_inports;
+       const int *outports;
+       const int *child_ids;
+       const int *child_ports;
+       int nr_outports;
+       bool default_sink;
+       struct clk *clk;
+};
+
+struct coresight_desc {
+       enum coresight_dev_type type;
+       struct coresight_dev_subtype subtype;
+       const struct coresight_ops *ops;
+       struct coresight_platform_data *pdata;
+       struct device *dev;
+       const struct coresight_ops_entry **debugfs_ops;
+       struct module *owner;
+};
+
+struct coresight_connection {
+       int outport;
+       int child_id;
+       int child_port;
+       struct coresight_device *child_dev;
+       struct list_head link;
+};
+
+struct coresight_refcnt {
+       int sink_refcnt;
+       int *link_refcnts;
+       int source_refcnt;
+};
+
+struct coresight_device {
+       int id;
+       struct coresight_connection *conns;
+       int nr_conns;
+       enum coresight_dev_type type;
+       struct coresight_dev_subtype subtype;
+       const struct coresight_ops *ops;
+       struct dentry *de;
+       struct device dev;
+       struct coresight_refcnt refcnt;
+       struct list_head dev_link;
+       struct list_head path_link;
+       struct module *owner;
+       bool enable;
+};
+
+#define to_coresight_device(d) container_of(d, struct coresight_device, dev)
+
+#define CORESIGHT_DEBUGFS_ENTRY(__name, __entry_name,                  \
+                                __mode, __get, __set, __fmt)           \
+DEFINE_SIMPLE_ATTRIBUTE(__name ## _ops, __get, __set, __fmt)           \
+static const struct coresight_ops_entry __name ## _entry = {           \
+       .name = __entry_name,                                           \
+       .mode = __mode,                                                 \
+       .ops  = &__name ## _ops                                         \
+}
+
+struct coresight_ops_sink {
+       int (*enable)(struct coresight_device *csdev);
+       void (*disable)(struct coresight_device *csdev);
+       void (*abort)(struct coresight_device *csdev);
+};
+
+struct coresight_ops_link {
+       int (*enable)(struct coresight_device *csdev, int iport, int oport);
+       void (*disable)(struct coresight_device *csdev, int iport, int oport);
+};
+
+struct coresight_ops_source {
+       int (*enable)(struct coresight_device *csdev);
+       void (*disable)(struct coresight_device *csdev);
+};
+
+struct coresight_ops {
+       const struct coresight_ops_sink *sink_ops;
+       const struct coresight_ops_link *link_ops;
+       const struct coresight_ops_source *sourcearch/arm64/kernel/smp.c_ops;
+};
+
+#ifdef CONFIG_CORESIGHT
+extern struct coresight_device *
+coresight_register(struct coresight_desc *desc);
+extern void coresight_unregister(struct coresight_device *csdev);
+extern int coresight_enable(struct coresight_device *csdev);
+extern void coresight_disable(struct coresight_device *csdev);
+extern void coresight_abort(void);
+extern struct clk *coresight_get_clk(void);
+#else
+static inline struct coresight_device *
+coresight_register(struct coresight_desc *desc) { return NULL; }
+static inline void coresight_unregister(struct coresight_device *csdev) {}
+static inline int
+coresight_enable(struct coresight_device *csdev) { return -ENOSYS; }
+static inline void coresight_disable(struct coresight_device *csdev) {}
+static inline void coresight_abort(void) {}
+extern struct clk *coresight_get_clk(void) {};
+#endif
+
+#endif

diff --git a/include/linux/of_coresight.h b/include/linux/of_coresight.h
new file mode 100644
index 0000000..6a5e4d4
--- /dev/null
+++ b/include/linux/of_coresight.h

I would just put this into coresight.h.

quoted

@@ -0,0 +1,27 @@
+/* Copyright (c) 2012, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __LINUX_OF_CORESIGHT_H
+#define __LINUX_OF_CORESIGHT_H
+
+#ifdef CONFIG_OF
+extern struct coresight_platform_data *of_get_coresight_platform_data(
+                               struct device *dev, struct device_node *node);
+#else
+static inline struct coresight_platform_data *of_get_coresight_platform_data(
+                               struct device *dev, struct device_node *node)
+{
+       return NULL;
+}
+#endif
+
+#endif
--

1.9.1