kernel/drivers/hwtracing/coresight/coresight-replicator.c

   1 /* Copyright (c) 2011-2012, 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/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/device.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/io.h>
  18 #include <linux/err.h>
  19 #include <linux/slab.h>
  20 #include <linux/pm_runtime.h>
  21 #include <linux/clk.h>
  22 #include <linux/of.h>
  23 #include <linux/coresight.h>
  24
  25 #include "coresight-priv.h"
  26
  27 /**
  28  * struct replicator_drvdata - specifics associated to a replicator component
  29  * @dev:        the device entity associated with this component
  30  * @atclk:      optional clock for the core parts of the replicator.
  31  * @csdev:      component vitals needed by the framework
  32  */
  33 struct replicator_drvdata {
  34         struct device           *dev;
  35         struct clk              *atclk;
  36         struct coresight_device *csdev;
  37 };
  38
  39 static int replicator_enable(struct coresight_device *csdev, int inport,
  40                              int outport)
  41 {
  42         struct replicator_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
  43
  44         pm_runtime_get_sync(drvdata->dev);
  45         dev_info(drvdata->dev, "REPLICATOR enabled\n");
  46         return 0;
  47 }
  48
  49 static void replicator_disable(struct coresight_device *csdev, int inport,
  50                                int outport)
  51 {
  52         struct replicator_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
  53
  54         pm_runtime_put(drvdata->dev);
  55         dev_info(drvdata->dev, "REPLICATOR disabled\n");
  56 }
  57
  58 static const struct coresight_ops_link replicator_link_ops = {
  59         .enable         = replicator_enable,
  60         .disable        = replicator_disable,
  61 };
  62
  63 static const struct coresight_ops replicator_cs_ops = {
  64         .link_ops       = &replicator_link_ops,
  65 };
  66
  67 static int replicator_probe(struct platform_device *pdev)
  68 {
  69         int ret;
  70         struct device *dev = &pdev->dev;
  71         struct coresight_platform_data *pdata = NULL;
  72         struct replicator_drvdata *drvdata;
  73         struct coresight_desc *desc;
  74         struct device_node *np = pdev->dev.of_node;
  75
  76         if (np) {
  77                 pdata = of_get_coresight_platform_data(dev, np);
  78                 if (IS_ERR(pdata))
  79                         return PTR_ERR(pdata);
  80                 pdev->dev.platform_data = pdata;
  81         }
  82
  83         drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
  84         if (!drvdata)
  85                 return -ENOMEM;
  86
  87         drvdata->dev = &pdev->dev;
  88         drvdata->atclk = devm_clk_get(&pdev->dev, "atclk"); /* optional */
  89         if (!IS_ERR(drvdata->atclk)) {
  90                 ret = clk_prepare_enable(drvdata->atclk);
  91                 if (ret)
  92                         return ret;
  93         }
  94         pm_runtime_get_noresume(&pdev->dev);
  95         pm_runtime_set_active(&pdev->dev);
  96         pm_runtime_enable(&pdev->dev);
  97         platform_set_drvdata(pdev, drvdata);
  98
  99         desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
 100         if (!desc) {
 101                 ret = -ENOMEM;
 102                 goto out_disable_pm;
 103         }
 104
 105         desc->type = CORESIGHT_DEV_TYPE_LINK;
 106         desc->subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_SPLIT;
 107         desc->ops = &replicator_cs_ops;
 108         desc->pdata = pdev->dev.platform_data;
 109         desc->dev = &pdev->dev;
 110         drvdata->csdev = coresight_register(desc);
 111         if (IS_ERR(drvdata->csdev)) {
 112                 ret = PTR_ERR(drvdata->csdev);
 113                 goto out_disable_pm;
 114         }
 115
 116         pm_runtime_put(&pdev->dev);
 117
 118         dev_info(dev, "REPLICATOR initialized\n");
 119         return 0;
 120
 121 out_disable_pm:
 122         if (!IS_ERR(drvdata->atclk))
 123                 clk_disable_unprepare(drvdata->atclk);
 124         pm_runtime_put_noidle(&pdev->dev);
 125         pm_runtime_disable(&pdev->dev);
 126
 127         return ret;
 128 }
 129
 130 static int replicator_remove(struct platform_device *pdev)
 131 {
 132         struct replicator_drvdata *drvdata = platform_get_drvdata(pdev);
 133
 134         coresight_unregister(drvdata->csdev);
 135         pm_runtime_get_sync(&pdev->dev);
 136         if (!IS_ERR(drvdata->atclk))
 137                 clk_disable_unprepare(drvdata->atclk);
 138         pm_runtime_put_noidle(&pdev->dev);
 139         pm_runtime_disable(&pdev->dev);
 140
 141         return 0;
 142 }
 143
 144 #ifdef CONFIG_PM
 145 static int replicator_runtime_suspend(struct device *dev)
 146 {
 147         struct replicator_drvdata *drvdata = dev_get_drvdata(dev);
 148
 149         if (drvdata && !IS_ERR(drvdata->atclk))
 150                 clk_disable_unprepare(drvdata->atclk);
 151
 152         return 0;
 153 }
 154
 155 static int replicator_runtime_resume(struct device *dev)
 156 {
 157         struct replicator_drvdata *drvdata = dev_get_drvdata(dev);
 158
 159         if (drvdata && !IS_ERR(drvdata->atclk))
 160                 clk_prepare_enable(drvdata->atclk);
 161
 162         return 0;
 163 }
 164 #endif
 165
 166 static const struct dev_pm_ops replicator_dev_pm_ops = {
 167         SET_RUNTIME_PM_OPS(replicator_runtime_suspend,
 168                            replicator_runtime_resume, NULL)
 169 };
 170
 171 static const struct of_device_id replicator_match[] = {
 172         {.compatible = "arm,coresight-replicator"},
 173         {}
 174 };
 175
 176 static struct platform_driver replicator_driver = {
 177         .probe          = replicator_probe,
 178         .remove         = replicator_remove,
 179         .driver         = {
 180                 .name   = "coresight-replicator",
 181                 .of_match_table = replicator_match,
 182                 .pm     = &replicator_dev_pm_ops,
 183         },
 184 };
 185
 186 builtin_platform_driver(replicator_driver);
 187
 188 MODULE_LICENSE("GPL v2");
 189 MODULE_DESCRIPTION("CoreSight Replicator driver");