kernel/drivers/hwtracing/coresight/of_coresight.c

   1 /* Copyright (c) 2012, The Linux Foundation. All rights reserved.
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License version 2 and
   5  * only version 2 as published by the Free Software Foundation.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/types.h>
  15 #include <linux/err.h>
  16 #include <linux/slab.h>
  17 #include <linux/clk.h>
  18 #include <linux/of.h>
  19 #include <linux/of_address.h>
  20 #include <linux/of_graph.h>
  21 #include <linux/of_platform.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/amba/bus.h>
  24 #include <linux/coresight.h>
  25 #include <linux/cpumask.h>
  26 #include <asm/smp_plat.h>
  27
  28
  29 static int of_dev_node_match(struct device *dev, void *data)
  30 {
  31         return dev->of_node == data;
  32 }
  33
  34 static struct device *
  35 of_coresight_get_endpoint_device(struct device_node *endpoint)
  36 {
  37         struct device *dev = NULL;
  38
  39         /*
  40          * If we have a non-configuable replicator, it will be found on the
  41          * platform bus.
  42          */
  43         dev = bus_find_device(&platform_bus_type, NULL,
  44                               endpoint, of_dev_node_match);
  45         if (dev)
  46                 return dev;
  47
  48         /*
  49          * We have a configurable component - circle through the AMBA bus
  50          * looking for the device that matches the endpoint node.
  51          */
  52         return bus_find_device(&amba_bustype, NULL,
  53                                endpoint, of_dev_node_match);
  54 }
  55
  56 static void of_coresight_get_ports(struct device_node *node,
  57                                    int *nr_inport, int *nr_outport)
  58 {
  59         struct device_node *ep = NULL;
  60         int in = 0, out = 0;
  61
  62         do {
  63                 ep = of_graph_get_next_endpoint(node, ep);
  64                 if (!ep)
  65                         break;
  66
  67                 if (of_property_read_bool(ep, "slave-mode"))
  68                         in++;
  69                 else
  70                         out++;
  71
  72         } while (ep);
  73
  74         *nr_inport = in;
  75         *nr_outport = out;
  76 }
  77
  78 static int of_coresight_alloc_memory(struct device *dev,
  79                         struct coresight_platform_data *pdata)
  80 {
  81         /* List of output port on this component */
  82         pdata->outports = devm_kzalloc(dev, pdata->nr_outport *
  83                                        sizeof(*pdata->outports),
  84                                        GFP_KERNEL);
  85         if (!pdata->outports)
  86                 return -ENOMEM;
  87
  88         /* Children connected to this component via @outports */
  89          pdata->child_names = devm_kzalloc(dev, pdata->nr_outport *
  90                                           sizeof(*pdata->child_names),
  91                                           GFP_KERNEL);
  92         if (!pdata->child_names)
  93                 return -ENOMEM;
  94
  95         /* Port number on the child this component is connected to */
  96         pdata->child_ports = devm_kzalloc(dev, pdata->nr_outport *
  97                                           sizeof(*pdata->child_ports),
  98                                           GFP_KERNEL);
  99         if (!pdata->child_ports)
 100                 return -ENOMEM;
 101
 102         return 0;
 103 }
 104
 105 struct coresight_platform_data *of_get_coresight_platform_data(
 106                                 struct device *dev, struct device_node *node)
 107 {
 108         int i = 0, ret = 0, cpu;
 109         struct coresight_platform_data *pdata;
 110         struct of_endpoint endpoint, rendpoint;
 111         struct device *rdev;
 112         struct device_node *dn;
 113         struct device_node *ep = NULL;
 114         struct device_node *rparent = NULL;
 115         struct device_node *rport = NULL;
 116
 117         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 118         if (!pdata)
 119                 return ERR_PTR(-ENOMEM);
 120
 121         /* Use device name as sysfs handle */
 122         pdata->name = dev_name(dev);
 123
 124         /* Get the number of input and output port for this component */
 125         of_coresight_get_ports(node, &pdata->nr_inport, &pdata->nr_outport);
 126
 127         if (pdata->nr_outport) {
 128                 ret = of_coresight_alloc_memory(dev, pdata);
 129                 if (ret)
 130                         return ERR_PTR(ret);
 131
 132                 /* Iterate through each port to discover topology */
 133                 do {
 134                         /* Get a handle on a port */
 135                         ep = of_graph_get_next_endpoint(node, ep);
 136                         if (!ep)
 137                                 break;
 138
 139                         /*
 140                          * No need to deal with input ports, processing for as
 141                          * processing for output ports will deal with them.
 142                          */
 143                         if (of_find_property(ep, "slave-mode", NULL))
 144                                 continue;
 145
 146                         /* Get a handle on the local endpoint */
 147                         ret = of_graph_parse_endpoint(ep, &endpoint);
 148
 149                         if (ret)
 150                                 continue;
 151
 152                         /* The local out port number */
 153                         pdata->outports[i] = endpoint.id;
 154
 155                         /*
 156                          * Get a handle on the remote port and parent
 157                          * attached to it.
 158                          */
 159                         rparent = of_graph_get_remote_port_parent(ep);
 160                         rport = of_graph_get_remote_port(ep);
 161
 162                         if (!rparent || !rport)
 163                                 continue;
 164
 165                         if (of_graph_parse_endpoint(rport, &rendpoint))
 166                                 continue;
 167
 168                         rdev = of_coresight_get_endpoint_device(rparent);
 169                         if (!rdev)
 170                                 continue;
 171
 172                         pdata->child_names[i] = dev_name(rdev);
 173                         pdata->child_ports[i] = rendpoint.id;
 174
 175                         i++;
 176                 } while (ep);
 177         }
 178
 179         /* Affinity defaults to CPU0 */
 180         pdata->cpu = 0;
 181         dn = of_parse_phandle(node, "cpu", 0);
 182         for (cpu = 0; dn && cpu < nr_cpu_ids; cpu++) {
 183                 if (dn == of_get_cpu_node(cpu, NULL)) {
 184                         pdata->cpu = cpu;
 185                         break;
 186                 }
 187         }
 188
 189         return pdata;
 190 }
 191 EXPORT_SYMBOL_GPL(of_get_coresight_platform_data);