drivers/bus/tegra-aconnect.c

   1 /*
   2  * Tegra ACONNECT Bus Driver
   3  *
   4  * Copyright (C) 2016, NVIDIA CORPORATION.  All rights reserved.
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License.  See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  */
  10
  11 #include <linux/clk.h>
  12 #include <linux/module.h>
  13 #include <linux/of_platform.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/pm_runtime.h>
  16
  17 struct tegra_aconnect {
  18         struct clk      *ape_clk;
  19         struct clk      *apb2ape_clk;
  20 };
  21
  22 static int tegra_aconnect_probe(struct platform_device *pdev)
  23 {
  24         struct tegra_aconnect *aconnect;
  25
  26         if (!pdev->dev.of_node)
  27                 return -EINVAL;
  28
  29         aconnect = devm_kzalloc(&pdev->dev, sizeof(struct tegra_aconnect),
  30                                 GFP_KERNEL);
  31         if (!aconnect)
  32                 return -ENOMEM;
  33
  34         aconnect->ape_clk = devm_clk_get(&pdev->dev, "ape");
  35         if (IS_ERR(aconnect->ape_clk)) {
  36                 dev_err(&pdev->dev, "Can't retrieve ape clock\n");
  37                 return PTR_ERR(aconnect->ape_clk);
  38         }
  39
  40         aconnect->apb2ape_clk = devm_clk_get(&pdev->dev, "apb2ape");
  41         if (IS_ERR(aconnect->apb2ape_clk)) {
  42                 dev_err(&pdev->dev, "Can't retrieve apb2ape clock\n");
  43                 return PTR_ERR(aconnect->apb2ape_clk);
  44         }
  45
  46         dev_set_drvdata(&pdev->dev, aconnect);
  47         pm_runtime_enable(&pdev->dev);
  48
  49         of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
  50
  51         dev_info(&pdev->dev, "Tegra ACONNECT bus registered\n");
  52
  53         return 0;
  54 }
  55
  56 static int tegra_aconnect_remove(struct platform_device *pdev)
  57 {
  58         pm_runtime_disable(&pdev->dev);
  59
  60         return 0;
  61 }
  62
  63 static int tegra_aconnect_runtime_resume(struct device *dev)
  64 {
  65         struct tegra_aconnect *aconnect = dev_get_drvdata(dev);
  66         int ret;
  67
  68         ret = clk_prepare_enable(aconnect->ape_clk);
  69         if (ret) {
  70                 dev_err(dev, "ape clk_enable failed: %d\n", ret);
  71                 return ret;
  72         }
  73
  74         ret = clk_prepare_enable(aconnect->apb2ape_clk);
  75         if (ret) {
  76                 clk_disable_unprepare(aconnect->ape_clk);
  77                 dev_err(dev, "apb2ape clk_enable failed: %d\n", ret);
  78                 return ret;
  79         }
  80
  81         return 0;
  82 }
  83
  84 static int tegra_aconnect_runtime_suspend(struct device *dev)
  85 {
  86         struct tegra_aconnect *aconnect = dev_get_drvdata(dev);
  87
  88         clk_disable_unprepare(aconnect->ape_clk);
  89         clk_disable_unprepare(aconnect->apb2ape_clk);
  90
  91         return 0;
  92 }
  93
  94 static const struct dev_pm_ops tegra_aconnect_pm_ops = {
  95         SET_RUNTIME_PM_OPS(tegra_aconnect_runtime_suspend,
  96                            tegra_aconnect_runtime_resume, NULL)
  97         SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
  98                                       pm_runtime_force_resume)
  99 };
 100
 101 static const struct of_device_id tegra_aconnect_of_match[] = {
 102         { .compatible = "nvidia,tegra210-aconnect", },
 103         { }
 104 };
 105 MODULE_DEVICE_TABLE(of, tegra_aconnect_of_match);
 106
 107 static struct platform_driver tegra_aconnect_driver = {
 108         .probe = tegra_aconnect_probe,
 109         .remove = tegra_aconnect_remove,
 110         .driver = {
 111                 .name = "tegra-aconnect",
 112                 .of_match_table = tegra_aconnect_of_match,
 113                 .pm = &tegra_aconnect_pm_ops,
 114         },
 115 };
 116 module_platform_driver(tegra_aconnect_driver);
 117
 118 MODULE_DESCRIPTION("NVIDIA Tegra ACONNECT Bus Driver");
 119 MODULE_AUTHOR("Jon Hunter <jonathanh@nvidia.com>");
 120 MODULE_LICENSE("GPL v2");