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/types.h>
  14 #include <linux/err.h>
  15 #include <linux/slab.h>
  16 #include <linux/clk.h>
  17 #include <linux/of.h>
  18 #include <linux/of_address.h>
  19 #include <linux/of_graph.h>
  20 #include <linux/of_platform.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/amba/bus.h>
  23 #include <linux/coresight.h>
  24 #include <linux/cpumask.h>
  25 #include <asm/smp_plat.h>
  26
  27
  28 static int of_dev_node_match(struct device *dev, void *data)
  29 {
  30         return dev->of_node == data;
  31 }
  32
  33 static struct device *
  34 of_coresight_get_endpoint_device(struct device_node *endpoint)
  35 {
  36         struct device *dev = NULL;
  37
  38         /*
  39          * If we have a non-configurable replicator, it will be found on the
  40          * platform bus.
  41          */
  42         dev = bus_find_device(&platform_bus_type, NULL,
  43                               endpoint, of_dev_node_match);
  44         if (dev)
  45                 return dev;
  46
  47         /*
  48          * We have a configurable component - circle through the AMBA bus
  49          * looking for the device that matches the endpoint node.
  50          */
  51         return bus_find_device(&amba_bustype, NULL,
  52                                endpoint, of_dev_node_match);
  53 }
  54
  55 static void of_coresight_get_ports(const struct device_node *node,
  56                                    int *nr_inport, int *nr_outport)
  57 {
  58         struct device_node *ep = NULL;
  59         int in = 0, out = 0;
  60
  61         do {
  62                 ep = of_graph_get_next_endpoint(node, ep);
  63                 if (!ep)
  64                         break;
  65
  66                 if (of_property_read_bool(ep, "slave-mode"))
  67                         in++;
  68                 else
  69                         out++;
  70
  71         } while (ep);
  72
  73         *nr_inport = in;
  74         *nr_outport = out;
  75 }
  76
  77 static int of_coresight_alloc_memory(struct device *dev,
  78                         struct coresight_platform_data *pdata)
  79 {
  80         /* List of output port on this component */
  81         pdata->outports = devm_kzalloc(dev, pdata->nr_outport *
  82                                        sizeof(*pdata->outports),
  83                                        GFP_KERNEL);
  84         if (!pdata->outports)
  85                 return -ENOMEM;
  86
  87         /* Children connected to this component via @outports */
  88         pdata->child_names = devm_kzalloc(dev, pdata->nr_outport *
  89                                           sizeof(*pdata->child_names),
  90                                           GFP_KERNEL);
  91         if (!pdata->child_names)
  92                 return -ENOMEM;
  93
  94         /* Port number on the child this component is connected to */
  95         pdata->child_ports = devm_kzalloc(dev, pdata->nr_outport *
  96                                           sizeof(*pdata->child_ports),
  97                                           GFP_KERNEL);
  98         if (!pdata->child_ports)
  99                 return -ENOMEM;
 100
 101         return 0;
 102 }
 103
 104 int of_coresight_get_cpu(const struct device_node *node)
 105 {
 106         int cpu;
 107         struct device_node *dn;
 108
 109         dn = of_parse_phandle(node, "cpu", 0);
 110         /* Affinity defaults to CPU0 */
 111         if (!dn)
 112                 return 0;
 113         cpu = of_cpu_node_to_id(dn);
 114         of_node_put(dn);
 115
 116         /* Affinity to CPU0 if no cpu nodes are found */
 117         return (cpu < 0) ? 0 : cpu;
 118 }
 119 EXPORT_SYMBOL_GPL(of_coresight_get_cpu);
 120
 121 struct coresight_platform_data *
 122 of_get_coresight_platform_data(struct device *dev,
 123                                const struct device_node *node)
 124 {
 125         int i = 0, ret = 0;
 126         struct coresight_platform_data *pdata;
 127         struct of_endpoint endpoint, rendpoint;
 128         struct device *rdev;
 129         struct device_node *ep = NULL;
 130         struct device_node *rparent = NULL;
 131         struct device_node *rport = NULL;
 132
 133         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 134         if (!pdata)
 135                 return ERR_PTR(-ENOMEM);
 136
 137         /* Use device name as sysfs handle */
 138         pdata->name = dev_name(dev);
 139
 140         /* Get the number of input and output port for this component */
 141         of_coresight_get_ports(node, &pdata->nr_inport, &pdata->nr_outport);
 142
 143         if (pdata->nr_outport) {
 144                 ret = of_coresight_alloc_memory(dev, pdata);
 145                 if (ret)
 146                         return ERR_PTR(ret);
 147
 148                 /* Iterate through each port to discover topology */
 149                 do {
 150                         /* Get a handle on a port */
 151                         ep = of_graph_get_next_endpoint(node, ep);
 152                         if (!ep)
 153                                 break;
 154
 155                         /*
 156                          * No need to deal with input ports, processing for as
 157                          * processing for output ports will deal with them.
 158                          */
 159                         if (of_find_property(ep, "slave-mode", NULL))
 160                                 continue;
 161
 162                         /* Get a handle on the local endpoint */
 163                         ret = of_graph_parse_endpoint(ep, &endpoint);
 164
 165                         if (ret)
 166                                 continue;
 167
 168                         /* The local out port number */
 169                         pdata->outports[i] = endpoint.port;
 170
 171                         /*
 172                          * Get a handle on the remote port and parent
 173                          * attached to it.
 174                          */
 175                         rparent = of_graph_get_remote_port_parent(ep);
 176                         rport = of_graph_get_remote_port(ep);
 177
 178                         if (!rparent || !rport)
 179                                 continue;
 180
 181                         if (of_graph_parse_endpoint(rport, &rendpoint))
 182                                 continue;
 183
 184                         rdev = of_coresight_get_endpoint_device(rparent);
 185                         if (!rdev)
 186                                 return ERR_PTR(-EPROBE_DEFER);
 187
 188                         pdata->child_names[i] = dev_name(rdev);
 189                         pdata->child_ports[i] = rendpoint.id;
 190
 191                         i++;
 192                 } while (ep);
 193         }
 194
 195         pdata->cpu = of_coresight_get_cpu(node);
 196
 197         return pdata;
 198 }
 199 EXPORT_SYMBOL_GPL(of_get_coresight_platform_data);