diff options
Diffstat (limited to 'drivers/cpufreq/tegra124-cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/tegra124-cpufreq.c | 214 |
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 000000000000..20bcceb58ccc --- /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"); |