[PATCH v4 2/2] cpufreq: tegra124: Allow building as a module

Aaron Kling via B4 Relay
2025-05-09T00:04:17Z

From: Aaron Kling <webgeek1234@gmail.com>

This requires three changes:
* A soft dependency on cpufreq-dt as this driver only handles power
management and cpufreq-dt does the real operations
* Adding a remove routine to remove the cpufreq-dt device
* Adding a exit routine to handle cleaning up the driver

Signed-off-by: Aaron Kling <webgeek1234@gmail.com>
---
drivers/cpufreq/Kconfig.arm | 2 +-
drivers/cpufreq/tegra124-cpufreq.c | 36 ++++++++++++++++++++++++++++++++----
2 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 4f9cb943d945c244eb2b29f543d14df6cac4e5d4..625f6fbdaaf5fd774e3b0bb996eb7ce980da41ee 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -238,7 +238,7 @@ config ARM_TEGRA20_CPUFREQ
This adds the CPUFreq driver support for Tegra20/30 SOCs.

config ARM_TEGRA124_CPUFREQ
- bool "Tegra124 CPUFreq support"
+ tristate "Tegra124 CPUFreq support"
depends on ARCH_TEGRA || COMPILE_TEST
depends on CPUFREQ_DT
default y
diff --git a/drivers/cpufreq/tegra124-cpufreq.c b/drivers/cpufreq/tegra124-cpufreq.c
index bc0691e8971f9454def37f489e4a3e244100b9f4..b6059c91f2474c56809c403eca94eacf51df734f 100644
--- a/drivers/cpufreq/tegra124-cpufreq.c
+++ b/drivers/cpufreq/tegra124-cpufreq.c
@@ -16,6 +16,8 @@
#include <linux/pm_opp.h>
#include <linux/types.h>

+static struct platform_device *platform_device;
+
struct tegra124_cpufreq_priv {
struct clk *cpu_clk;
struct clk *pllp_clk;
@@ -176,6 +178,21 @@ static int __maybe_unused tegra124_cpufreq_resume(struct device *dev)
return err;
}

+static void tegra124_cpufreq_remove(struct platform_device *pdev)
+{
+ struct tegra124_cpufreq_priv *priv = dev_get_drvdata(&pdev->dev);
+
+ if (!IS_ERR(priv->cpufreq_dt_pdev)) {
+ platform_device_unregister(priv->cpufreq_dt_pdev);
+ priv->cpufreq_dt_pdev = ERR_PTR(-ENODEV);
+ }
+
+ clk_put(priv->pllp_clk);
+ clk_put(priv->pllx_clk);
+ clk_put(priv->dfll_clk);
+ clk_put(priv->cpu_clk);
+}
+
static const struct dev_pm_ops tegra124_cpufreq_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(tegra124_cpufreq_suspend,
tegra124_cpufreq_resume)
@@ -185,12 +202,12 @@ static struct platform_driver tegra124_cpufreq_platdrv = {
.driver.name = "cpufreq-tegra124",
.driver.pm = &tegra124_cpufreq_pm_ops,
.probe = tegra124_cpufreq_probe,
+ .remove = tegra124_cpufreq_remove,
};

static int __init tegra_cpufreq_init(void)
{
int ret;
- struct platform_device *pdev;

if (!(of_machine_is_compatible("nvidia,tegra124") ||
of_machine_is_compatible("nvidia,tegra210")))
@@ -204,15 +221,26 @@ static int __init tegra_cpufreq_init(void)
if (ret)
return ret;

- pdev = platform_device_register_simple("cpufreq-tegra124", -1, NULL, 0);
- if (IS_ERR(pdev)) {
+ platform_device = platform_device_register_simple("cpufreq-tegra124", -1, NULL, 0);
+ if (IS_ERR(platform_device)) {
platform_driver_unregister(&tegra124_cpufreq_platdrv);
- return PTR_ERR(pdev);
+ return PTR_ERR(platform_device);
}

return 0;
}
module_init(tegra_cpufreq_init);

+static void __exit tegra_cpufreq_module_exit(void)
+{
+ if (platform_device && !IS_ERR(platform_device))
+ platform_device_unregister(platform_device);
+
+ platform_driver_unregister(&tegra124_cpufreq_platdrv);
+}
+module_exit(tegra_cpufreq_module_exit);
+
+MODULE_SOFTDEP("pre: cpufreq-dt");
MODULE_AUTHOR("Tuomas Tynkkynen <ttynkkynen@nvidia.com>");
MODULE_DESCRIPTION("cpufreq driver for NVIDIA Tegra124");
+MODULE_LICENSE("GPL");

--
2.48.1