1 files changed, 240 insertions, 0 deletions

diff --git a/drivers/cpufreq/tegra124-cpufreq.c b/drivers/cpufreq/tegra124-cpufreq.c
new file mode 100644
index 000000000000..f8a76bbecef9
--- /dev/null
+++ b/drivers/cpufreq/tegra124-cpufreq.c
@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Tegra 124 cpufreq driver
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <linux/clk.h>
+#include <linux/cpufreq.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/types.h>
+
+#include "cpufreq-dt.h"
+
+static struct platform_device *tegra124_cpufreq_pdev;
+
+struct tegra124_cpufreq_priv {
+	struct clk *cpu_clk;
+	struct clk *pllp_clk;
+	struct clk *pllx_clk;
+	struct clk *dfll_clk;
+	struct platform_device *cpufreq_dt_pdev;
+};
+
+static int tegra124_cpu_switch_to_dfll(struct tegra124_cpufreq_priv *priv)
+{
+	struct clk *orig_parent;
+	int ret;
+
+	ret = clk_set_rate(priv->dfll_clk, clk_get_rate(priv->cpu_clk));
+	if (ret)
+		return ret;
+
+	orig_parent = clk_get_parent(priv->cpu_clk);
+	clk_set_parent(priv->cpu_clk, priv->pllp_clk);
+
+	ret = clk_prepare_enable(priv->dfll_clk);
+	if (ret)
+		goto out;
+
+	clk_set_parent(priv->cpu_clk, priv->dfll_clk);
+
+	return 0;
+
+out:
+	clk_set_parent(priv->cpu_clk, orig_parent);
+
+	return ret;
+}
+
+static int tegra124_cpufreq_probe(struct platform_device *pdev)
+{
+	struct device_node *np __free(device_node) = of_cpu_device_node_get(0);
+	struct tegra124_cpufreq_priv *priv;
+	struct device *cpu_dev;
+	int ret;
+
+	if (!np)
+		return -ENODEV;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	cpu_dev = get_cpu_device(0);
+	if (!cpu_dev)
+		return -ENODEV;
+
+	priv->cpu_clk = of_clk_get_by_name(np, "cpu_g");
+	if (IS_ERR(priv->cpu_clk))
+		return PTR_ERR(priv->cpu_clk);
+
+	priv->dfll_clk = of_clk_get_by_name(np, "dfll");
+	if (IS_ERR(priv->dfll_clk)) {
+		ret = PTR_ERR(priv->dfll_clk);
+		goto out_put_cpu_clk;
+	}
+
+	priv->pllx_clk = of_clk_get_by_name(np, "pll_x");
+	if (IS_ERR(priv->pllx_clk)) {
+		ret = PTR_ERR(priv->pllx_clk);
+		goto out_put_dfll_clk;
+	}
+
+	priv->pllp_clk = of_clk_get_by_name(np, "pll_p");
+	if (IS_ERR(priv->pllp_clk)) {
+		ret = PTR_ERR(priv->pllp_clk);
+		goto out_put_pllx_clk;
+	}
+
+	ret = tegra124_cpu_switch_to_dfll(priv);
+	if (ret)
+		goto out_put_pllp_clk;
+
+	priv->cpufreq_dt_pdev = cpufreq_dt_pdev_register(&pdev->dev);
+	if (IS_ERR(priv->cpufreq_dt_pdev)) {
+		ret = PTR_ERR(priv->cpufreq_dt_pdev);
+		goto out_put_pllp_clk;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	return 0;
+
+out_put_pllp_clk:
+	clk_put(priv->pllp_clk);
+out_put_pllx_clk:
+	clk_put(priv->pllx_clk);
+out_put_dfll_clk:
+	clk_put(priv->dfll_clk);
+out_put_cpu_clk:
+	clk_put(priv->cpu_clk);
+
+	return ret;
+}
+
+static int __maybe_unused tegra124_cpufreq_suspend(struct device *dev)
+{
+	struct tegra124_cpufreq_priv *priv = dev_get_drvdata(dev);
+	int err;
+
+	/*
+	 * PLLP rate 408Mhz is below the CPU Fmax at Vmin and is safe to
+	 * use during suspend and resume. So, switch the CPU clock source
+	 * to PLLP and disable DFLL.
+	 */
+	err = clk_set_parent(priv->cpu_clk, priv->pllp_clk);
+	if (err < 0) {
+		dev_err(dev, "failed to reparent to PLLP: %d\n", err);
+		return err;
+	}
+
+	clk_disable_unprepare(priv->dfll_clk);
+
+	return 0;
+}
+
+static int __maybe_unused tegra124_cpufreq_resume(struct device *dev)
+{
+	struct tegra124_cpufreq_priv *priv = dev_get_drvdata(dev);
+	int err;
+
+	/*
+	 * Warmboot code powers up the CPU with PLLP clock source.
+	 * Enable DFLL clock and switch CPU clock source back to DFLL.
+	 */
+	err = clk_prepare_enable(priv->dfll_clk);
+	if (err < 0) {
+		dev_err(dev, "failed to enable DFLL clock for CPU: %d\n", err);
+		goto disable_cpufreq;
+	}
+
+	err = clk_set_parent(priv->cpu_clk, priv->dfll_clk);
+	if (err < 0) {
+		dev_err(dev, "failed to reparent to DFLL clock: %d\n", err);
+		goto disable_dfll;
+	}
+
+	return 0;
+
+disable_dfll:
+	clk_disable_unprepare(priv->dfll_clk);
+disable_cpufreq:
+	disable_cpufreq();
+
+	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)
+};
+
+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;
+
+	if (!(of_machine_is_compatible("nvidia,tegra114") ||
+	      of_machine_is_compatible("nvidia,tegra124") ||
+	      of_machine_is_compatible("nvidia,tegra210")))
+		return -ENODEV;
+
+	/*
+	 * Platform driver+device required for handling EPROBE_DEFER with
+	 * the regulator and the DFLL clock
+	 */
+	ret = platform_driver_register(&tegra124_cpufreq_platdrv);
+	if (ret)
+		return ret;
+
+	tegra124_cpufreq_pdev = platform_device_register_simple("cpufreq-tegra124", -1, NULL, 0);
+	if (IS_ERR(tegra124_cpufreq_pdev)) {
+		platform_driver_unregister(&tegra124_cpufreq_platdrv);
+		return PTR_ERR(tegra124_cpufreq_pdev);
+	}
+
+	return 0;
+}
+module_init(tegra_cpufreq_init);
+
+static void __exit tegra_cpufreq_module_exit(void)
+{
+	if (!IS_ERR_OR_NULL(tegra124_cpufreq_pdev))
+		platform_device_unregister(tegra124_cpufreq_pdev);
+
+	platform_driver_unregister(&tegra124_cpufreq_platdrv);
+}
+module_exit(tegra_cpufreq_module_exit);
+
+MODULE_AUTHOR("Tuomas Tynkkynen <ttynkkynen@nvidia.com>");
+MODULE_DESCRIPTION("cpufreq driver for NVIDIA Tegra124");
+MODULE_LICENSE("GPL");