linux/drivers/bus/tegra-aconnect.c
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   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
  17struct tegra_aconnect {
  18        struct clk      *ape_clk;
  19        struct clk      *apb2ape_clk;
  20};
  21
  22static 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
  56static int tegra_aconnect_remove(struct platform_device *pdev)
  57{
  58        pm_runtime_disable(&pdev->dev);
  59
  60        return 0;
  61}
  62
  63static 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
  84static 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
  94static 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
 101static const struct of_device_id tegra_aconnect_of_match[] = {
 102        { .compatible = "nvidia,tegra210-aconnect", },
 103        { }
 104};
 105MODULE_DEVICE_TABLE(of, tegra_aconnect_of_match);
 106
 107static 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};
 116module_platform_driver(tegra_aconnect_driver);
 117
 118MODULE_DESCRIPTION("NVIDIA Tegra ACONNECT Bus Driver");
 119MODULE_AUTHOR("Jon Hunter <jonathanh@nvidia.com>");
 120MODULE_LICENSE("GPL v2");
 121