target/linux/ipq806x/patches/0172-cpufreq-Add-a-cpufreq-krait-based-on-cpufreq-cpu0.patch

   1 From 5cf343c60d7557aefb468603065cac5062f11b8d Mon Sep 17 00:00:00 2001
   2 From: Stephen Boyd <sboyd@codeaurora.org>
   3 Date: Fri, 30 May 2014 16:36:11 -0700
   4 Subject: [PATCH 172/182] cpufreq: Add a cpufreq-krait based on cpufreq-cpu0
   5
   6 Krait processors have individual clocks for each CPU that can
   7 scale independently from one another. cpufreq-cpu0 is fairly
   8 close to this, but assumes that there is only one clock for all
   9 CPUs. Add a driver to support the Krait configuration.
  10
  11 TODO: Merge into cpufreq-cpu0? Or make generic?
  12
  13 Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
  14 ---
  15  drivers/cpufreq/Kconfig         |   13 +++
  16  drivers/cpufreq/Makefile        |    1 +
  17  drivers/cpufreq/cpufreq-krait.c |  190 +++++++++++++++++++++++++++++++++++++++
  18  3 files changed, 204 insertions(+)
  19  create mode 100644 drivers/cpufreq/cpufreq-krait.c
  20
  21 diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
  22 index 4b029c0..4051528 100644
  23 --- a/drivers/cpufreq/Kconfig
  24 +++ b/drivers/cpufreq/Kconfig
  25 @@ -194,6 +194,19 @@ config GENERIC_CPUFREQ_CPU0
  26
  27           If in doubt, say N.
  28
  29 +config GENERIC_CPUFREQ_KRAIT
  30 +       tristate "Krait cpufreq driver"
  31 +       depends on HAVE_CLK && OF
  32 +       # if CPU_THERMAL is on and THERMAL=m, CPU0 cannot be =y:
  33 +       depends on !CPU_THERMAL || THERMAL
  34 +       select PM_OPP
  35 +       help
  36 +         This adds a generic cpufreq driver for CPU0 frequency management.
  37 +         It supports both uniprocessor (UP) and symmetric multiprocessor (SMP)
  38 +         systems which share clock and voltage across all CPUs.
  39 +
  40 +         If in doubt, say N.
  41 +
  42  menu "x86 CPU frequency scaling drivers"
  43  depends on X86
  44  source "drivers/cpufreq/Kconfig.x86"
  45 diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
  46 index 7494565..f6f4485 100644
  47 --- a/drivers/cpufreq/Makefile
  48 +++ b/drivers/cpufreq/Makefile
  49 @@ -12,6 +12,7 @@ obj-$(CONFIG_CPU_FREQ_GOV_CONSERVATIVE)       += cpufreq_conservative.o
  50  obj-$(CONFIG_CPU_FREQ_GOV_COMMON)              += cpufreq_governor.o
  51
  52  obj-$(CONFIG_GENERIC_CPUFREQ_CPU0)     += cpufreq-cpu0.o
  53 +obj-$(CONFIG_GENERIC_CPUFREQ_KRAIT)    += cpufreq-krait.o
  54
  55  ##################################################################################
  56  # x86 drivers.
  57 diff --git a/drivers/cpufreq/cpufreq-krait.c b/drivers/cpufreq/cpufreq-krait.c
  58 new file mode 100644
  59 index 0000000..7b38b9c
  60 --- /dev/null
  61 +++ b/drivers/cpufreq/cpufreq-krait.c
  62 @@ -0,0 +1,190 @@
  63 +/*
  64 + * Copyright (C) 2012 Freescale Semiconductor, Inc.
  65 + * Copyright (c) 2014, The Linux Foundation. All rights reserved.
  66 + *
  67 + * The OPP code in function krait_set_target() is reused from
  68 + * drivers/cpufreq/omap-cpufreq.c
  69 + *
  70 + * This program is free software; you can redistribute it and/or modify
  71 + * it under the terms of the GNU General Public License version 2 as
  72 + * published by the Free Software Foundation.
  73 + */
  74 +
  75 +#include <linux/clk.h>
  76 +#include <linux/cpu.h>
  77 +#include <linux/cpu_cooling.h>
  78 +#include <linux/cpufreq.h>
  79 +#include <linux/cpumask.h>
  80 +#include <linux/err.h>
  81 +#include <linux/module.h>
  82 +#include <linux/of.h>
  83 +#include <linux/pm_opp.h>
  84 +#include <linux/platform_device.h>
  85 +#include <linux/slab.h>
  86 +#include <linux/thermal.h>
  87 +
  88 +static unsigned int transition_latency;
  89 +
  90 +static struct device *cpu_dev;
  91 +static DEFINE_PER_CPU(struct clk *, krait_cpu_clks);
  92 +static struct cpufreq_frequency_table *freq_table;
  93 +static struct thermal_cooling_device *cdev;
  94 +
  95 +static int krait_set_target(struct cpufreq_policy *policy, unsigned int index)
  96 +{
  97 +       unsigned long volt = 0, volt_old = 0;
  98 +       unsigned int old_freq, new_freq;
  99 +       long freq_Hz, freq_exact;
 100 +       int ret;
 101 +       struct clk *cpu_clk;
 102 +
 103 +       cpu_clk = per_cpu(krait_cpu_clks, policy->cpu);
 104 +
 105 +       freq_Hz = clk_round_rate(cpu_clk, freq_table[index].frequency * 1000);
 106 +       if (freq_Hz <= 0)
 107 +               freq_Hz = freq_table[index].frequency * 1000;
 108 +
 109 +       freq_exact = freq_Hz;
 110 +       new_freq = freq_Hz / 1000;
 111 +       old_freq = clk_get_rate(cpu_clk) / 1000;
 112 +
 113 +       pr_debug("%u MHz, %ld mV --> %u MHz, %ld mV\n",
 114 +                old_freq / 1000, volt_old ? volt_old / 1000 : -1,
 115 +                new_freq / 1000, volt ? volt / 1000 : -1);
 116 +
 117 +       ret = clk_set_rate(cpu_clk, freq_exact);
 118 +       if (ret)
 119 +               pr_err("failed to set clock rate: %d\n", ret);
 120 +
 121 +       return ret;
 122 +}
 123 +
 124 +static int krait_cpufreq_init(struct cpufreq_policy *policy)
 125 +{
 126 +       int ret;
 127 +
 128 +       policy->clk = per_cpu(krait_cpu_clks, policy->cpu);
 129 +
 130 +       ret = cpufreq_table_validate_and_show(policy, freq_table);
 131 +       if (ret) {
 132 +               pr_err("%s: invalid frequency table: %d\n", __func__, ret);
 133 +               return ret;
 134 +       }
 135 +
 136 +       policy->cpuinfo.transition_latency = transition_latency;
 137 +
 138 +       return 0;
 139 +}
 140 +
 141 +static struct cpufreq_driver krait_cpufreq_driver = {
 142 +       .flags = CPUFREQ_STICKY,
 143 +       .verify = cpufreq_generic_frequency_table_verify,
 144 +       .target_index = krait_set_target,
 145 +       .get = cpufreq_generic_get,
 146 +       .init = krait_cpufreq_init,
 147 +       .name = "generic_krait",
 148 +       .attr = cpufreq_generic_attr,
 149 +};
 150 +
 151 +static int krait_cpufreq_probe(struct platform_device *pdev)
 152 +{
 153 +       struct device_node *np;
 154 +       int ret;
 155 +       unsigned int cpu;
 156 +       struct device *dev;
 157 +       struct clk *clk;
 158 +
 159 +       cpu_dev = get_cpu_device(0);
 160 +       if (!cpu_dev) {
 161 +               pr_err("failed to get krait device\n");
 162 +               return -ENODEV;
 163 +       }
 164 +
 165 +       np = of_node_get(cpu_dev->of_node);
 166 +       if (!np) {
 167 +               pr_err("failed to find krait node\n");
 168 +               return -ENOENT;
 169 +       }
 170 +
 171 +       for_each_possible_cpu(cpu) {
 172 +               dev = get_cpu_device(cpu);
 173 +               if (!dev) {
 174 +                       pr_err("failed to get krait device\n");
 175 +                       ret = -ENOENT;
 176 +                       goto out_put_node;
 177 +               }
 178 +               per_cpu(krait_cpu_clks, cpu) = clk = devm_clk_get(dev, NULL);
 179 +               if (IS_ERR(clk)) {
 180 +                       ret = PTR_ERR(clk);
 181 +                       goto out_put_node;
 182 +               }
 183 +       }
 184 +
 185 +       ret = of_init_opp_table(cpu_dev);
 186 +       if (ret) {
 187 +               pr_err("failed to init OPP table: %d\n", ret);
 188 +               goto out_put_node;
 189 +       }
 190 +
 191 +       ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table);
 192 +       if (ret) {
 193 +               pr_err("failed to init cpufreq table: %d\n", ret);
 194 +               goto out_put_node;
 195 +       }
 196 +
 197 +       if (of_property_read_u32(np, "clock-latency", &transition_latency))
 198 +               transition_latency = CPUFREQ_ETERNAL;
 199 +
 200 +       ret = cpufreq_register_driver(&krait_cpufreq_driver);
 201 +       if (ret) {
 202 +               pr_err("failed register driver: %d\n", ret);
 203 +               goto out_free_table;
 204 +       }
 205 +       of_node_put(np);
 206 +
 207 +       /*
 208 +        * For now, just loading the cooling device;
 209 +        * thermal DT code takes care of matching them.
 210 +        */
 211 +       for_each_possible_cpu(cpu) {
 212 +               dev = get_cpu_device(cpu);
 213 +               np = of_node_get(dev->of_node);
 214 +               if (of_find_property(np, "#cooling-cells", NULL)) {
 215 +                       cdev = of_cpufreq_cooling_register(np, cpumask_of(cpu));
 216 +                       if (IS_ERR(cdev))
 217 +                               pr_err("running cpufreq without cooling device: %ld\n",
 218 +                                      PTR_ERR(cdev));
 219 +               }
 220 +               of_node_put(np);
 221 +       }
 222 +
 223 +       return 0;
 224 +
 225 +out_free_table:
 226 +       dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
 227 +out_put_node:
 228 +       of_node_put(np);
 229 +       return ret;
 230 +}
 231 +
 232 +static int krait_cpufreq_remove(struct platform_device *pdev)
 233 +{
 234 +       cpufreq_cooling_unregister(cdev);
 235 +       cpufreq_unregister_driver(&krait_cpufreq_driver);
 236 +       dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table);
 237 +
 238 +       return 0;
 239 +}
 240 +
 241 +static struct platform_driver krait_cpufreq_platdrv = {
 242 +       .driver = {
 243 +               .name   = "cpufreq-krait",
 244 +               .owner  = THIS_MODULE,
 245 +       },
 246 +       .probe          = krait_cpufreq_probe,
 247 +       .remove         = krait_cpufreq_remove,
 248 +};
 249 +module_platform_driver(krait_cpufreq_platdrv);
 250 +
 251 +MODULE_DESCRIPTION("Krait CPUfreq driver");
 252 +MODULE_LICENSE("GPL v2");
 253 --
 254 1.7.10.4
 255