Quelle  tegra20-cpufreq.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2010 Google, Inc.
 *
 * Author:
 * Colin Cross <ccross@google.com>
 * Based on arch/arm/plat-omap/cpu-omap.c, (C) 2005 Nokia Corporation
 */

#include <linux/bits.h>
#include <linux/cpu.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_opp.h>
#include <linux/types.h>

#include <soc/tegra/common.h>
#include <soc/tegra/fuse.h>

static bool cpu0_node_has_opp_v2_prop(void)
{
 struct device_node *np = of_cpu_device_node_get(0);
 bool ret = false;

 if (of_property_present(np, "operating-points-v2"))
  ret = true;

 of_node_put(np);
 return ret;
}

static void tegra20_cpufreq_put_supported_hw(void *opp_token)
{
 dev_pm_opp_put_supported_hw((unsigned long) opp_token);
}

static void tegra20_cpufreq_dt_unregister(void *cpufreq_dt)
{
 platform_device_unregister(cpufreq_dt);
}

static int tegra20_cpufreq_probe(struct platform_device *pdev)
{
 struct platform_device *cpufreq_dt;
 struct device *cpu_dev;
 u32 versions[2];
 int err;

 if (!cpu0_node_has_opp_v2_prop()) {
  dev_err(&pdev->dev, "operating points not found\n");
  dev_err(&pdev->dev, "please update your device tree\n");
  return -ENODEV;
 }

 if (of_machine_is_compatible("nvidia,tegra20")) {
  versions[0] = BIT(tegra_sku_info.cpu_process_id);
  versions[1] = BIT(tegra_sku_info.soc_speedo_id);
 } else {
  versions[0] = BIT(tegra_sku_info.cpu_process_id);
  versions[1] = BIT(tegra_sku_info.cpu_speedo_id);
 }

 dev_info(&pdev->dev, "hardware version 0x%x 0x%x\n",
   versions[0], versions[1]);

 cpu_dev = get_cpu_device(0);
 if (WARN_ON(!cpu_dev))
  return -ENODEV;

 err = dev_pm_opp_set_supported_hw(cpu_dev, versions, 2);
 if (err < 0) {
  dev_err(&pdev->dev, "failed to set supported hw: %d\n", err);
  return err;
 }

 err = devm_add_action_or_reset(&pdev->dev,
           tegra20_cpufreq_put_supported_hw,
           (void *)((unsigned long) err));
 if (err)
  return err;

 cpufreq_dt = platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
 err = PTR_ERR_OR_ZERO(cpufreq_dt);
 if (err) {
  dev_err(&pdev->dev,
   "failed to create cpufreq-dt device: %d\n", err);
  return err;
 }

 err = devm_add_action_or_reset(&pdev->dev,
           tegra20_cpufreq_dt_unregister,
           cpufreq_dt);
 if (err)
  return err;

 return 0;
}

static struct platform_driver tegra20_cpufreq_driver = {
 .probe  = tegra20_cpufreq_probe,
 .driver  = {
  .name = "tegra20-cpufreq",
 },
};
module_platform_driver(tegra20_cpufreq_driver);

MODULE_ALIAS("platform:tegra20-cpufreq");
MODULE_AUTHOR("Colin Cross ");
MODULE_DESCRIPTION("NVIDIA Tegra20 cpufreq driver");
MODULE_LICENSE("GPL");