/* * 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/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 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; 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");