From dd77db4143290689d3a5e1ec61627233d0711b66 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Fri, 30 May 2014 16:36:11 -0700 Subject: [PATCH] FROMLIST: cpufreq: Add a cpufreq-krait based on cpufreq-cpu0 Krait processors have individual clocks for each CPU that can scale independently from one another. cpufreq-cpu0 is fairly close to this, but assumes that there is only one clock for all CPUs. Add a driver to support the Krait configuration. TODO: Merge into cpufreq-cpu0? Or make generic? Signed-off-by: Stephen Boyd --- drivers/cpufreq/Kconfig | 13 +++ drivers/cpufreq/Makefile | 1 + drivers/cpufreq/cpufreq-krait.c | 190 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 204 insertions(+) create mode 100644 drivers/cpufreq/cpufreq-krait.c --- a/drivers/cpufreq/Kconfig +++ b/drivers/cpufreq/Kconfig @@ -196,6 +196,19 @@ config CPUFREQ_DT If in doubt, say N. +config GENERIC_CPUFREQ_KRAIT + tristate "Krait cpufreq driver" + depends on HAVE_CLK && OF + # if CPU_THERMAL is on and THERMAL=m, CPU0 cannot be =y: + depends on !CPU_THERMAL || THERMAL + select PM_OPP + help + This adds a generic cpufreq driver for CPU0 frequency management. + It supports both uniprocessor (UP) and symmetric multiprocessor (SMP) + systems which share clock and voltage across all CPUs. + + If in doubt, say N. + menu "x86 CPU frequency scaling drivers" depends on X86 source "drivers/cpufreq/Kconfig.x86" --- a/drivers/cpufreq/Makefile +++ b/drivers/cpufreq/Makefile @@ -14,6 +14,7 @@ obj-$(CONFIG_CPU_FREQ_GOV_CONSERVATIVE) obj-$(CONFIG_CPU_FREQ_GOV_COMMON) += cpufreq_governor.o obj-$(CONFIG_CPUFREQ_DT) += cpufreq-dt.o +obj-$(CONFIG_GENERIC_CPUFREQ_KRAIT) += cpufreq-krait.o ################################################################################## # x86 drivers. --- /dev/null +++ b/drivers/cpufreq/cpufreq-krait.c @@ -0,0 +1,390 @@ +/* + * Copyright (C) 2012 Freescale Semiconductor, Inc. + * Copyright (c) 2014, The Linux Foundation. All rights reserved. + * + * The OPP code in function krait_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. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static unsigned int transition_latency; +static unsigned int voltage_tolerance; /* in percentage */ + +static struct device *cpu_dev; +static DEFINE_PER_CPU(struct clk *, krait_cpu_clks); +static DEFINE_PER_CPU(struct regulator *, krait_supply_core); +static struct cpufreq_frequency_table *freq_table; +static struct thermal_cooling_device *cdev; + +struct cache_points { + unsigned long cache_freq; + unsigned int cache_volt; + unsigned long cpu_freq; +}; + +static struct regulator *krait_l2_reg; +static struct clk *krait_l2_clk; +static struct cache_points *krait_l2_points; +static int nr_krait_l2_points; + +static int krait_parse_cache_points(struct device *dev, + struct device_node *of_node) +{ + const struct property *prop; + const __be32 *val; + int nr, i; + + prop = of_find_property(of_node, "cache-points-kHz", NULL); + if (!prop) + return -ENODEV; + if (!prop->value) + return -ENODATA; + + /* + * Each OPP is a set of tuples consisting of frequency and + * cpu-frequency like . + */ + nr = prop->length / sizeof(u32); + if (nr % 3) { + dev_err(dev, "%s: Invalid cache points\n", __func__); + return -EINVAL; + } + nr /= 3; + + krait_l2_points = devm_kcalloc(dev, nr, sizeof(*krait_l2_points), + GFP_KERNEL); + if (!krait_l2_points) + return -ENOMEM; + nr_krait_l2_points = nr; + + for (i = 0, val = prop->value; i < nr; i++) { + unsigned long cache_freq = be32_to_cpup(val++) * 1000; + unsigned int cache_volt = be32_to_cpup(val++); + unsigned long cpu_freq = be32_to_cpup(val++) * 1000; + + krait_l2_points[i].cache_freq = cache_freq; + krait_l2_points[i].cache_volt = cache_volt; + krait_l2_points[i].cpu_freq = cpu_freq; + } + + return 0; +} + +static int krait_set_target(struct cpufreq_policy *policy, unsigned int index) +{ + struct dev_pm_opp *opp; + unsigned long volt = 0, volt_old = 0, tol = 0; + unsigned long freq, max_cpu_freq = 0; + unsigned int old_freq, new_freq; + long freq_Hz, freq_exact; + int ret, i; + struct clk *cpu_clk; + struct regulator *core; + unsigned int cpu; + + cpu_clk = per_cpu(krait_cpu_clks, policy->cpu); + + 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; + + core = per_cpu(krait_supply_core, policy->cpu); + + rcu_read_lock(); + opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_Hz); + if (IS_ERR(opp)) { + rcu_read_unlock(); + pr_err("failed to find OPP for %ld\n", freq_Hz); + return PTR_ERR(opp); + } + volt = dev_pm_opp_get_voltage(opp); + rcu_read_unlock(); + tol = volt * voltage_tolerance / 100; + volt_old = regulator_get_voltage(core); + + pr_debug("%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 (new_freq > old_freq) { + ret = regulator_set_voltage_tol(core, volt, tol); + if (ret) { + pr_err("failed to scale voltage up: %d\n", ret); + return ret; + } + } + + ret = clk_set_rate(cpu_clk, freq_exact); + if (ret) { + pr_err("failed to set clock rate: %d\n", ret); + return ret; + } + + /* scaling down? scale voltage after frequency */ + if (new_freq < old_freq) { + ret = regulator_set_voltage_tol(core, volt, tol); + if (ret) { + pr_err("failed to scale voltage down: %d\n", ret); + clk_set_rate(cpu_clk, old_freq * 1000); + } + } + + for_each_possible_cpu(cpu) { + freq = clk_get_rate(per_cpu(krait_cpu_clks, cpu)); + max_cpu_freq = max(max_cpu_freq, freq); + } + + for (i = 0; i < nr_krait_l2_points; i++) { + if (max_cpu_freq >= krait_l2_points[i].cpu_freq) { + if (krait_l2_reg) { + ret = regulator_set_voltage_tol(krait_l2_reg, + krait_l2_points[i].cache_volt, + tol); + if (ret) { + pr_err("failed to scale l2 voltage: %d\n", + ret); + } + } + ret = clk_set_rate(krait_l2_clk, + krait_l2_points[i].cache_freq); + if (ret) + pr_err("failed to scale l2 clk: %d\n", ret); + break; + } + + } + + return ret; +} + +static int krait_cpufreq_init(struct cpufreq_policy *policy) +{ + int ret; + + policy->clk = per_cpu(krait_cpu_clks, policy->cpu); + + ret = cpufreq_table_validate_and_show(policy, freq_table); + if (ret) { + pr_err("%s: invalid frequency table: %d\n", __func__, ret); + return ret; + } + + policy->cpuinfo.transition_latency = transition_latency; + + return 0; +} + +static struct cpufreq_driver krait_cpufreq_driver = { + .flags = CPUFREQ_STICKY, + .verify = cpufreq_generic_frequency_table_verify, + .target_index = krait_set_target, + .get = cpufreq_generic_get, + .init = krait_cpufreq_init, + .name = "generic_krait", + .attr = cpufreq_generic_attr, +}; + +static int krait_cpufreq_probe(struct platform_device *pdev) +{ + struct device_node *np, *cache; + int ret, i; + unsigned int cpu; + struct device *dev; + struct clk *clk; + struct regulator *core; + unsigned long freq_Hz, freq, max_cpu_freq = 0; + struct dev_pm_opp *opp; + unsigned long volt, tol; + + cpu_dev = get_cpu_device(0); + if (!cpu_dev) { + pr_err("failed to get krait device\n"); + return -ENODEV; + } + + np = of_node_get(cpu_dev->of_node); + if (!np) { + pr_err("failed to find krait node\n"); + return -ENOENT; + } + + 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_put_node; + } + + of_property_read_u32(np, "voltage-tolerance", &voltage_tolerance); + + if (of_property_read_u32(np, "clock-latency", &transition_latency)) + transition_latency = CPUFREQ_ETERNAL; + + cache = of_find_next_cache_node(np); + if (cache) { + struct device_node *vdd; + + vdd = of_parse_phandle(cache, "vdd_dig-supply", 0); + if (vdd) { + krait_l2_reg = regulator_get(NULL, vdd->name); + if (IS_ERR(krait_l2_reg)) { + pr_warn("failed to get l2 vdd_dig supply\n"); + krait_l2_reg = NULL; + } + of_node_put(vdd); + } + + krait_l2_clk = of_clk_get(cache, 0); + if (!IS_ERR(krait_l2_clk)) { + ret = krait_parse_cache_points(&pdev->dev, cache); + if (ret) + clk_put(krait_l2_clk); + } + if (IS_ERR(krait_l2_clk) || ret) + krait_l2_clk = NULL; + } + + for_each_possible_cpu(cpu) { + dev = get_cpu_device(cpu); + if (!dev) { + pr_err("failed to get krait device\n"); + ret = -ENOENT; + goto out_free_table; + } + per_cpu(krait_cpu_clks, cpu) = clk = devm_clk_get(dev, NULL); + if (IS_ERR(clk)) { + ret = PTR_ERR(clk); + goto out_free_table; + } + core = devm_regulator_get(dev, "core"); + if (IS_ERR(core)) { + pr_debug("failed to get core regulator\n"); + ret = PTR_ERR(core); + goto out_free_table; + } + per_cpu(krait_supply_core, cpu) = core; + + freq = freq_Hz = clk_get_rate(clk); + + rcu_read_lock(); + opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_Hz); + if (IS_ERR(opp)) { + rcu_read_unlock(); + pr_err("failed to find OPP for %ld\n", freq_Hz); + ret = PTR_ERR(opp); + goto out_free_table; + } + volt = dev_pm_opp_get_voltage(opp); + rcu_read_unlock(); + + tol = volt * voltage_tolerance / 100; + ret = regulator_set_voltage_tol(core, volt, tol); + if (ret) { + pr_err("failed to scale voltage up: %d\n", ret); + goto out_free_table; + } + ret = regulator_enable(core); + if (ret) { + pr_err("failed to enable regulator: %d\n", ret); + goto out_free_table; + } + max_cpu_freq = max(max_cpu_freq, freq); + } + + for (i = 0; i < nr_krait_l2_points; i++) { + if (max_cpu_freq >= krait_l2_points[i].cpu_freq) { + if (krait_l2_reg) { + ret = regulator_set_voltage_tol(krait_l2_reg, + krait_l2_points[i].cache_volt, + tol); + if (ret) + pr_err("failed to scale l2 voltage: %d\n", + ret); + ret = regulator_enable(krait_l2_reg); + if (ret) + pr_err("failed to enable l2 voltage: %d\n", + ret); + } + break; + } + + } + + ret = cpufreq_register_driver(&krait_cpufreq_driver); + if (ret) { + pr_err("failed register driver: %d\n", ret); + goto out_free_table; + } + of_node_put(np); + + /* + * For now, just loading the cooling device; + * thermal DT code takes care of matching them. + */ + for_each_possible_cpu(cpu) { + dev = get_cpu_device(cpu); + np = of_node_get(dev->of_node); + if (of_find_property(np, "#cooling-cells", NULL)) { + cdev = of_cpufreq_cooling_register(np, cpumask_of(cpu)); + if (IS_ERR(cdev)) + pr_err("running cpufreq without cooling device: %ld\n", + PTR_ERR(cdev)); + } + of_node_put(np); + } + + return 0; + +out_free_table: + regulator_put(krait_l2_reg); + clk_put(krait_l2_clk); + dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); +out_put_node: + of_node_put(np); + return ret; +} + +static int krait_cpufreq_remove(struct platform_device *pdev) +{ + cpufreq_cooling_unregister(cdev); + cpufreq_unregister_driver(&krait_cpufreq_driver); + dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); + clk_put(krait_l2_clk); + regulator_put(krait_l2_reg); + + return 0; +} + +static struct platform_driver krait_cpufreq_platdrv = { + .driver = { + .name = "cpufreq-krait", + .owner = THIS_MODULE, + }, + .probe = krait_cpufreq_probe, + .remove = krait_cpufreq_remove, +}; +module_platform_driver(krait_cpufreq_platdrv); + +MODULE_DESCRIPTION("Krait CPUfreq driver"); +MODULE_LICENSE("GPL v2"); --- a/drivers/cpufreq/qcom-cpufreq.c +++ b/drivers/cpufreq/qcom-cpufreq.c @@ -168,11 +168,8 @@ static int __init qcom_cpufreq_populate_ static int __init qcom_cpufreq_driver_init(void) { - struct cpufreq_dt_platform_data pdata = { .independent_clocks = true }; struct platform_device_info devinfo = { - .name = "cpufreq-dt", - .data = &pdata, - .size_data = sizeof(pdata), + .name = "cpufreq-krait", }; struct device *cpu_dev; struct device_node *np;