/* * Copyright (C) 2012 Freescale Semiconductor, Inc. * * Copyright (C) 2014 Linaro. * Viresh Kumar * * The OPP code in function set_target() is reused from * drivers/cpufreq/omap-cpufreq.c * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include struct private_data { struct device *cpu_dev; struct regulator *cpu_reg; struct thermal_cooling_device *cdev; unsigned int voltage_tolerance; /* in percentage */ }; static int set_target(struct cpufreq_policy *policy, unsigned int index) { struct dev_pm_opp *opp; struct cpufreq_frequency_table *freq_table = policy->freq_table; struct clk *cpu_clk = policy->clk; struct private_data *priv = policy->driver_data; struct device *cpu_dev = priv->cpu_dev; struct regulator *cpu_reg = priv->cpu_reg; unsigned long volt = 0, volt_old = 0, tol = 0; unsigned int old_freq, new_freq; long freq_Hz, freq_exact; int ret; freq_Hz = clk_round_rate(cpu_clk, freq_table[index].frequency * 1000); if (freq_Hz <= 0) freq_Hz = freq_table[index].frequency * 1000; freq_exact = freq_Hz; new_freq = freq_Hz / 1000; old_freq = clk_get_rate(cpu_clk) / 1000; if (!IS_ERR(cpu_reg)) { unsigned long opp_freq; rcu_read_lock(); opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_Hz); if (IS_ERR(opp)) { rcu_read_unlock(); dev_err(cpu_dev, "failed to find OPP for %ld\n", freq_Hz); return PTR_ERR(opp); } volt = dev_pm_opp_get_voltage(opp); opp_freq = dev_pm_opp_get_freq(opp); rcu_read_unlock(); tol = volt * priv->voltage_tolerance / 100; volt_old = regulator_get_voltage(cpu_reg); dev_dbg(cpu_dev, "Found OPP: %ld kHz, %ld uV\n", opp_freq / 1000, volt); } dev_dbg(cpu_dev, "%u MHz, %ld mV --> %u MHz, %ld mV\n", old_freq / 1000, volt_old ? volt_old / 1000 : -1, new_freq / 1000, volt ? volt / 1000 : -1); /* scaling up? scale voltage before frequency */ if (!IS_ERR(cpu_reg) && new_freq > old_freq) { ret = regulator_set_voltage_tol(cpu_reg, volt, tol); if (ret) { dev_err(cpu_dev, "failed to scale voltage up: %d\n", ret); return ret; } } ret = clk_set_rate(cpu_clk, freq_exact); if (ret) { dev_err(cpu_dev, "failed to set clock rate: %d\n", ret); if (!IS_ERR(cpu_reg)) regulator_set_voltage_tol(cpu_reg, volt_old, tol); return ret; } /* scaling down? scale voltage after frequency */ if (!IS_ERR(cpu_reg) && new_freq < old_freq) { ret = regulator_set_voltage_tol(cpu_reg, volt, tol); if (ret) { dev_err(cpu_dev, "failed to scale voltage down: %d\n", ret); clk_set_rate(cpu_clk, old_freq * 1000); } } return ret; } static int allocate_resources(int cpu, struct device **cdev, struct regulator **creg, struct clk **cclk) { struct device *cpu_dev; struct regulator *cpu_reg; struct clk *cpu_clk; int ret = 0; char *reg_cpu0 = "cpu0", *reg_cpu = "cpu", *reg; cpu_dev = get_cpu_device(cpu); if (!cpu_dev) { pr_err("failed to get cpu%d device\n", cpu); return -ENODEV; } /* Try "cpu0" for older DTs */ if (!cpu) reg = reg_cpu0; else reg = reg_cpu; try_again: cpu_reg = regulator_get_optional(cpu_dev, reg); if (IS_ERR(cpu_reg)) { /* * If cpu's regulator supply node is present, but regulator is * not yet registered, we should try defering probe. */ if (PTR_ERR(cpu_reg) == -EPROBE_DEFER) { dev_dbg(cpu_dev, "cpu%d regulator not ready, retry\n", cpu); return -EPROBE_DEFER; } /* Try with "cpu-supply" */ if (reg == reg_cpu0) { reg = reg_cpu; goto try_again; } dev_dbg(cpu_dev, "no regulator for cpu%d: %ld\n", cpu, PTR_ERR(cpu_reg)); } cpu_clk = clk_get(cpu_dev, NULL); if (IS_ERR(cpu_clk)) { /* put regulator */ if (!IS_ERR(cpu_reg)) regulator_put(cpu_reg); ret = PTR_ERR(cpu_clk); /* * If cpu's clk node is present, but clock is not yet * registered, we should try defering probe. */ if (ret == -EPROBE_DEFER) dev_dbg(cpu_dev, "cpu%d clock not ready, retry\n", cpu); else dev_err(cpu_dev, "failed to get cpu%d clock: %d\n", cpu, ret); } else { *cdev = cpu_dev; *creg = cpu_reg; *cclk = cpu_clk; } return ret; } static int cpufreq_init(struct cpufreq_policy *policy) { struct cpufreq_dt_platform_data *pd; struct cpufreq_frequency_table *freq_table; struct thermal_cooling_device *cdev; struct device_node *np; struct private_data *priv; struct device *cpu_dev; struct regulator *cpu_reg; struct clk *cpu_clk; unsigned long min_uV = ~0, max_uV = 0; unsigned int transition_latency; int ret; ret = allocate_resources(policy->cpu, &cpu_dev, &cpu_reg, &cpu_clk); if (ret) { pr_err("%s: Failed to allocate resources\n: %d", __func__, ret); return ret; } np = of_node_get(cpu_dev->of_node); if (!np) { dev_err(cpu_dev, "failed to find cpu%d node\n", policy->cpu); ret = -ENOENT; goto out_put_reg_clk; } /* OPPs might be populated at runtime, don't check for error here */ of_init_opp_table(cpu_dev); priv = kzalloc(sizeof(*priv), GFP_KERNEL); if (!priv) { ret = -ENOMEM; goto out_put_node; } of_property_read_u32(np, "voltage-tolerance", &priv->voltage_tolerance); if (of_property_read_u32(np, "clock-latency", &transition_latency)) transition_latency = CPUFREQ_ETERNAL; if (!IS_ERR(cpu_reg)) { unsigned long opp_freq = 0; /* * Disable any OPPs where the connected regulator isn't able to * provide the specified voltage and record minimum and maximum * voltage levels. */ while (1) { struct dev_pm_opp *opp; unsigned long opp_uV, tol_uV; rcu_read_lock(); opp = dev_pm_opp_find_freq_ceil(cpu_dev, &opp_freq); if (IS_ERR(opp)) { rcu_read_unlock(); break; } opp_uV = dev_pm_opp_get_voltage(opp); rcu_read_unlock(); tol_uV = opp_uV * priv->voltage_tolerance / 100; if (regulator_is_supported_voltage(cpu_reg, opp_uV, opp_uV + tol_uV)) { if (opp_uV < min_uV) min_uV = opp_uV; if (opp_uV > max_uV) max_uV = opp_uV; } else { dev_pm_opp_disable(cpu_dev, opp_freq); } opp_freq++; } ret = regulator_set_voltage_time(cpu_reg, min_uV, max_uV); if (ret > 0) transition_latency += ret * 1000; } ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table); if (ret) { pr_err("failed to init cpufreq table: %d\n", ret); goto out_free_priv; } /* * For now, just loading the cooling device; * thermal DT code takes care of matching them. */ if (of_find_property(np, "#cooling-cells", NULL)) { cdev = of_cpufreq_cooling_register(np, cpu_present_mask); if (IS_ERR(cdev)) dev_err(cpu_dev, "running cpufreq without cooling device: %ld\n", PTR_ERR(cdev)); else priv->cdev = cdev; } priv->cpu_dev = cpu_dev; priv->cpu_reg = cpu_reg; policy->driver_data = priv; policy->clk = cpu_clk; ret = cpufreq_table_validate_and_show(policy, freq_table); if (ret) { dev_err(cpu_dev, "%s: invalid frequency table: %d\n", __func__, ret); goto out_cooling_unregister; } policy->cpuinfo.transition_latency = transition_latency; pd = cpufreq_get_driver_data(); if (!pd || !pd->independent_clocks) cpumask_setall(policy->cpus); of_node_put(np); return 0; out_cooling_unregister: cpufreq_cooling_unregister(priv->cdev); dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); out_free_priv: kfree(priv); out_put_node: of_node_put(np); out_put_reg_clk: clk_put(cpu_clk); if (!IS_ERR(cpu_reg)) regulator_put(cpu_reg); return ret; } static int cpufreq_exit(struct cpufreq_policy *policy) { struct private_data *priv = policy->driver_data; cpufreq_cooling_unregister(priv->cdev); dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table); clk_put(policy->clk); if (!IS_ERR(priv->cpu_reg)) regulator_put(priv->cpu_reg); kfree(priv); return 0; } static struct cpufreq_driver dt_cpufreq_driver = { .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK, .verify = cpufreq_generic_frequency_table_verify, .target_index = set_target, .get = cpufreq_generic_get, .init = cpufreq_init, .exit = cpufreq_exit, .name = "cpufreq-dt", .attr = cpufreq_generic_attr, }; static int dt_cpufreq_probe(struct platform_device *pdev) { struct device *cpu_dev; struct regulator *cpu_reg; struct clk *cpu_clk; int ret; /* * All per-cluster (CPUs sharing clock/voltages) initialization is done * from ->init(). In probe(), we just need to make sure that clk and * regulators are available. Else defer probe and retry. * * FIXME: Is checking this only for CPU0 sufficient ? */ ret = allocate_resources(0, &cpu_dev, &cpu_reg, &cpu_clk); if (ret) return ret; clk_put(cpu_clk); if (!IS_ERR(cpu_reg)) regulator_put(cpu_reg); dt_cpufreq_driver.driver_data = dev_get_platdata(&pdev->dev); ret = cpufreq_register_driver(&dt_cpufreq_driver); if (ret) dev_err(cpu_dev, "failed register driver: %d\n", ret); return ret; } static int dt_cpufreq_remove(struct platform_device *pdev) { cpufreq_unregister_driver(&dt_cpufreq_driver); return 0; } static struct platform_driver dt_cpufreq_platdrv = { .driver = { .name = "cpufreq-dt", .owner = THIS_MODULE, }, .probe = dt_cpufreq_probe, .remove = dt_cpufreq_remove, }; module_platform_driver(dt_cpufreq_platdrv); MODULE_AUTHOR("Viresh Kumar "); MODULE_AUTHOR("Shawn Guo "); MODULE_DESCRIPTION("Generic cpufreq driver"); MODULE_LICENSE("GPL");