drivers/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 <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-configuable 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 struct device_node *of_get_coresight_endpoint(
  56                 const struct device_node *parent, struct device_node *prev)
  57 {
  58         struct device_node *node = of_graph_get_next_endpoint(parent, prev);
  59
  60         of_node_put(prev);
  61         return node;
  62 }
  63
  64 static void of_coresight_get_ports(struct device_node *node,
  65                                    int *nr_inport, int *nr_outport)
  66 {
  67         struct device_node *ep = NULL;
  68         int in = 0, out = 0;
  69
  70         do {
  71                 ep = of_get_coresight_endpoint(node, ep);
  72                 if (!ep)
  73                         break;
  74
  75                 if (of_property_read_bool(ep, "slave-mode"))
  76                         in++;
  77                 else
  78                         out++;
  79
  80         } while (ep);
  81
  82         *nr_inport = in;
  83         *nr_outport = out;
  84 }
  85
  86 static int of_coresight_alloc_memory(struct device *dev,
  87                         struct coresight_platform_data *pdata)
  88 {
  89         /* List of output port on this component */
  90         pdata->outports = devm_kzalloc(dev, pdata->nr_outport *
  91                                        sizeof(*pdata->outports),
  92                                        GFP_KERNEL);
  93         if (!pdata->outports)
  94                 return -ENOMEM;
  95
  96         /* Children connected to this component via @outport */
  97          pdata->child_names = devm_kzalloc(dev, pdata->nr_outport *
  98                                           sizeof(*pdata->child_names),
  99                                           GFP_KERNEL);
 100         if (!pdata->child_names)
 101                 return -ENOMEM;
 102
 103         /* Port number on the child this component is connected to */
 104         pdata->child_ports = devm_kzalloc(dev, pdata->nr_outport *
 105                                           sizeof(*pdata->child_ports),
 106                                           GFP_KERNEL);
 107         if (!pdata->child_ports)
 108                 return -ENOMEM;
 109
 110         return 0;
 111 }
 112
 113 struct coresight_platform_data *of_get_coresight_platform_data(
 114                                 struct device *dev, struct device_node *node)
 115 {
 116         int i = 0, ret = 0;
 117         struct coresight_platform_data *pdata;
 118         struct of_endpoint endpoint, rendpoint;
 119         struct device *rdev;
 120         struct device_node *cpu;
 121         struct device_node *ep = NULL;
 122         struct device_node *rparent = NULL;
 123         struct device_node *rport = NULL;
 124
 125         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 126         if (!pdata)
 127                 return ERR_PTR(-ENOMEM);
 128
 129         /* Use device name as debugfs handle */
 130         pdata->name = dev_name(dev);
 131
 132         /* Get the number of input and output port for this component */
 133         of_coresight_get_ports(node, &pdata->nr_inport, &pdata->nr_outport);
 134
 135         if (pdata->nr_outport) {
 136                 ret = of_coresight_alloc_memory(dev, pdata);
 137                 if (ret)
 138                         return ERR_PTR(ret);
 139
 140                 /* Iterate through each port to discover topology */
 141                 do {
 142                         /* Get a handle on a port */
 143                         ep = of_get_coresight_endpoint(node, ep);
 144                         if (!ep)
 145                                 break;
 146
 147                         /*
 148                          * No need to deal with input ports, processing for as
 149                          * processing for output ports will deal with them.
 150                          */
 151                         if (of_find_property(ep, "slave-mode", NULL))
 152                                 continue;
 153
 154                         /* Get a handle on the local endpoint */
 155                         ret = of_graph_parse_endpoint(ep, &endpoint);
 156
 157                         if (ret)
 158                                 continue;
 159
 160                         /* The local out port number */
 161                         pdata->outports[i] = endpoint.id;
 162
 163                         /*
 164                          * Get a handle on the remote port and parent
 165                          * attached to it.
 166                          */
 167                         rparent = of_graph_get_remote_port_parent(ep);
 168                         rport = of_graph_get_remote_port(ep);
 169
 170                         if (!rparent || !rport)
 171                                 continue;
 172
 173                         if (of_graph_parse_endpoint(rport, &rendpoint))
 174                                 continue;
 175
 176                         rdev = of_coresight_get_endpoint_device(rparent);
 177                         if (!dev)
 178                                 continue;
 179
 180                         pdata->child_names[i] = dev_name(rdev);
 181                         pdata->child_ports[i] = rendpoint.id;
 182
 183                         i++;
 184                 } while (ep);
 185         }
 186
 187         /* Affinity defaults to CPU0 */
 188         pdata->cpu = 0;
 189         cpu = of_parse_phandle(node, "cpu", 0);
 190         if (cpu) {
 191                 const u32 *mpidr;
 192                 int len, index;
 193
 194                 mpidr = of_get_property(cpu, "reg", &len);
 195                 if (mpidr && len == 4) {
 196                         index = get_logical_index(be32_to_cpup(mpidr));
 197                         if (index != -EINVAL)
 198                                 pdata->cpu = index;
 199                 }
 200         }
 201
 202         return pdata;
 203 }
 204 EXPORT_SYMBOL_GPL(of_get_coresight_platform_data);