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path: root/drivers/cpufreq/tegra124-cpufreq.c
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Diffstat (limited to 'drivers/cpufreq/tegra124-cpufreq.c')
-rw-r--r--drivers/cpufreq/tegra124-cpufreq.c214
1 files changed, 214 insertions, 0 deletions
diff --git a/drivers/cpufreq/tegra124-cpufreq.c b/drivers/cpufreq/tegra124-cpufreq.c
new file mode 100644
index 000000000..20bcceb58
--- /dev/null
+++ b/drivers/cpufreq/tegra124-cpufreq.c
@@ -0,0 +1,214 @@
+/*
+ * Tegra 124 cpufreq driver
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/clk.h>
+#include <linux/cpufreq-dt.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/regulator/consumer.h>
+#include <linux/types.h>
+
+struct tegra124_cpufreq_priv {
+ struct regulator *vdd_cpu_reg;
+ 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 void tegra124_cpu_switch_to_pllx(struct tegra124_cpufreq_priv *priv)
+{
+ clk_set_parent(priv->cpu_clk, priv->pllp_clk);
+ clk_disable_unprepare(priv->dfll_clk);
+ regulator_sync_voltage(priv->vdd_cpu_reg);
+ clk_set_parent(priv->cpu_clk, priv->pllx_clk);
+}
+
+static struct cpufreq_dt_platform_data cpufreq_dt_pd = {
+ .independent_clocks = false,
+};
+
+static int tegra124_cpufreq_probe(struct platform_device *pdev)
+{
+ struct tegra124_cpufreq_priv *priv;
+ struct device_node *np;
+ struct device *cpu_dev;
+ struct platform_device_info cpufreq_dt_devinfo = {};
+ int ret;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ cpu_dev = get_cpu_device(0);
+ if (!cpu_dev)
+ return -ENODEV;
+
+ np = of_cpu_device_node_get(0);
+ if (!np)
+ return -ENODEV;
+
+ priv->vdd_cpu_reg = regulator_get(cpu_dev, "vdd-cpu");
+ if (IS_ERR(priv->vdd_cpu_reg)) {
+ ret = PTR_ERR(priv->vdd_cpu_reg);
+ goto out_put_np;
+ }
+
+ priv->cpu_clk = of_clk_get_by_name(np, "cpu_g");
+ if (IS_ERR(priv->cpu_clk)) {
+ ret = PTR_ERR(priv->cpu_clk);
+ goto out_put_vdd_cpu_reg;
+ }
+
+ 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;
+
+ cpufreq_dt_devinfo.name = "cpufreq-dt";
+ cpufreq_dt_devinfo.parent = &pdev->dev;
+ cpufreq_dt_devinfo.data = &cpufreq_dt_pd;
+ cpufreq_dt_devinfo.size_data = sizeof(cpufreq_dt_pd);
+
+ priv->cpufreq_dt_pdev =
+ platform_device_register_full(&cpufreq_dt_devinfo);
+ if (IS_ERR(priv->cpufreq_dt_pdev)) {
+ ret = PTR_ERR(priv->cpufreq_dt_pdev);
+ goto out_switch_to_pllx;
+ }
+
+ platform_set_drvdata(pdev, priv);
+
+ return 0;
+
+out_switch_to_pllx:
+ tegra124_cpu_switch_to_pllx(priv);
+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);
+out_put_vdd_cpu_reg:
+ regulator_put(priv->vdd_cpu_reg);
+out_put_np:
+ of_node_put(np);
+
+ return ret;
+}
+
+static int tegra124_cpufreq_remove(struct platform_device *pdev)
+{
+ struct tegra124_cpufreq_priv *priv = platform_get_drvdata(pdev);
+
+ platform_device_unregister(priv->cpufreq_dt_pdev);
+ tegra124_cpu_switch_to_pllx(priv);
+
+ clk_put(priv->pllp_clk);
+ clk_put(priv->pllx_clk);
+ clk_put(priv->dfll_clk);
+ clk_put(priv->cpu_clk);
+ regulator_put(priv->vdd_cpu_reg);
+
+ return 0;
+}
+
+static struct platform_driver tegra124_cpufreq_platdrv = {
+ .driver.name = "cpufreq-tegra124",
+ .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"))
+ 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;
+
+ pdev = platform_device_register_simple("cpufreq-tegra124", -1, NULL, 0);
+ if (IS_ERR(pdev)) {
+ platform_driver_unregister(&tegra124_cpufreq_platdrv);
+ return PTR_ERR(pdev);
+ }
+
+ return 0;
+}
+module_init(tegra_cpufreq_init);
+
+MODULE_AUTHOR("Tuomas Tynkkynen <ttynkkynen@nvidia.com>");
+MODULE_DESCRIPTION("cpufreq driver for NVIDIA Tegra124");
+MODULE_LICENSE("GPL v2");