target/linux/brcm2708/patches-3.10/011-bcm2835-cpufreq-driver.patch

   1 diff -urN linux-3.10/drivers/cpufreq/bcm2835-cpufreq.c linux-rpi-3.10.y/drivers/cpufreq/bcm2835-cpufreq.c
   2 --- linux-3.10/drivers/cpufreq/bcm2835-cpufreq.c        1970-01-01 01:00:00.000000000 +0100
   3 +++ linux-rpi-3.10.y/drivers/cpufreq/bcm2835-cpufreq.c  2013-07-06 15:25:50.000000000 +0100
   4 @@ -0,0 +1,239 @@
   5 +/*****************************************************************************
   6 +* Copyright 2011 Broadcom Corporation.  All rights reserved.
   7 +*
   8 +* Unless you and Broadcom execute a separate written software license
   9 +* agreement governing use of this software, this software is licensed to you
  10 +* under the terms of the GNU General Public License version 2, available at
  11 +* http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
  12 +*
  13 +* Notwithstanding the above, under no circumstances may you combine this
  14 +* software in any way with any other Broadcom software provided under a
  15 +* license other than the GPL, without Broadcom's express prior written
  16 +* consent.
  17 +*****************************************************************************/
  18 +
  19 +/*****************************************************************************
  20 +* FILENAME: bcm2835-cpufreq.h
  21 +* DESCRIPTION: This driver dynamically manages the CPU Frequency of the ARM
  22 +* processor. Messages are sent to Videocore either setting or requesting the
  23 +* frequency of the ARM in order to match an appropiate frequency to the current
  24 +* usage of the processor. The policy which selects the frequency to use is
  25 +* defined in the kernel .config file, but can be changed during runtime.
  26 +*****************************************************************************/
  27 +
  28 +/* ---------- INCLUDES ---------- */
  29 +#include <linux/kernel.h>
  30 +#include <linux/init.h>
  31 +#include <linux/module.h>
  32 +#include <linux/cpufreq.h>
  33 +#include <mach/vcio.h>
  34 +
  35 +/* ---------- DEFINES ---------- */
  36 +/*#define CPUFREQ_DEBUG_ENABLE*/               /* enable debugging */
  37 +#define MODULE_NAME "bcm2835-cpufreq"
  38 +
  39 +#define VCMSG_ID_ARM_CLOCK 0x000000003         /* Clock/Voltage ID's */
  40 +
  41 +/* debug printk macros */
  42 +#ifdef CPUFREQ_DEBUG_ENABLE
  43 +#define print_debug(fmt,...) pr_debug("%s:%s:%d: "fmt, MODULE_NAME, __func__, __LINE__, ##__VA_ARGS__)
  44 +#else
  45 +#define print_debug(fmt,...)
  46 +#endif
  47 +#define print_err(fmt,...) pr_err("%s:%s:%d: "fmt, MODULE_NAME, __func__,__LINE__, ##__VA_ARGS__)
  48 +#define print_info(fmt,...) pr_info("%s: "fmt, MODULE_NAME, ##__VA_ARGS__)
  49 +
  50 +/* tag part of the message */
  51 +struct vc_msg_tag {
  52 +       uint32_t tag_id;                /* the message id */
  53 +       uint32_t buffer_size;           /* size of the buffer (which in this case is always 8 bytes) */
  54 +       uint32_t data_size;             /* amount of data being sent or received */
  55 +       uint32_t dev_id;                /* the ID of the clock/voltage to get or set */
  56 +       uint32_t val;                   /* the value (e.g. rate (in Hz)) to set */
  57 +};
  58 +
  59 +/* message structure to be sent to videocore */
  60 +struct vc_msg {
  61 +       uint32_t msg_size;              /* simply, sizeof(struct vc_msg) */
  62 +       uint32_t request_code;          /* holds various information like the success and number of bytes returned (refer to mailboxes wiki) */
  63 +       struct vc_msg_tag tag;          /* the tag structure above to make */
  64 +       uint32_t end_tag;               /* an end identifier, should be set to NULL */
  65 +};
  66 +
  67 +/* ---------- GLOBALS ---------- */
  68 +static struct cpufreq_driver bcm2835_cpufreq_driver;   /* the cpufreq driver global */
  69 +
  70 +/*
  71 + ===============================================
  72 +  clk_rate either gets or sets the clock rates.
  73 + ===============================================
  74 +*/
  75 +static uint32_t bcm2835_cpufreq_set_clock(int cur_rate, int arm_rate)
  76 +{
  77 +       int s, actual_rate=0;
  78 +       struct vc_msg msg;
  79 +
  80 +       /* wipe all previous message data */
  81 +       memset(&msg, 0, sizeof msg);
  82 +
  83 +       msg.msg_size = sizeof msg;
  84 +
  85 +       msg.tag.tag_id = VCMSG_SET_CLOCK_RATE;
  86 +       msg.tag.buffer_size = 8;
  87 +       msg.tag.data_size = 8;   /* we're sending the clock ID and the new rates which is a total of 2 words */
  88 +       msg.tag.dev_id = VCMSG_ID_ARM_CLOCK;
  89 +       msg.tag.val = arm_rate * 1000;
  90 +
  91 +       /* send the message */
  92 +       s = bcm_mailbox_property(&msg, sizeof msg);
  93 +
  94 +       /* check if it was all ok and return the rate in KHz */
  95 +       if (s == 0 && (msg.request_code & 0x80000000))
  96 +               actual_rate = msg.tag.val/1000;
  97 +
  98 +       print_debug("Setting new frequency = %d -> %d (actual %d)\n", cur_rate, arm_rate, actual_rate);
  99 +       return actual_rate;
 100 +}
 101 +
 102 +static uint32_t bcm2835_cpufreq_get_clock(int tag)
 103 +{
 104 +       int s;
 105 +       int arm_rate = 0;
 106 +       struct vc_msg msg;
 107 +
 108 +       /* wipe all previous message data */
 109 +       memset(&msg, 0, sizeof msg);
 110 +
 111 +       msg.msg_size = sizeof msg;
 112 +       msg.tag.tag_id = tag;
 113 +       msg.tag.buffer_size = 8;
 114 +       msg.tag.data_size = 4; /* we're just sending the clock ID which is one word long */
 115 +       msg.tag.dev_id = VCMSG_ID_ARM_CLOCK;
 116 +
 117 +       /* send the message */
 118 +       s = bcm_mailbox_property(&msg, sizeof msg);
 119 +
 120 +       /* check if it was all ok and return the rate in KHz */
 121 +       if (s == 0 && (msg.request_code & 0x80000000))
 122 +               arm_rate = msg.tag.val/1000;
 123 +
 124 +       print_debug("%s frequency = %d\n",
 125 +               tag == VCMSG_GET_CLOCK_RATE ? "Current":
 126 +               tag == VCMSG_GET_MIN_CLOCK ? "Min":
 127 +               tag == VCMSG_GET_MAX_CLOCK ? "Max":
 128 +               "Unexpected", arm_rate);
 129 +
 130 +       return arm_rate;
 131 +}
 132 +
 133 +/*
 134 + ====================================================
 135 +  Module Initialisation registers the cpufreq driver
 136 + ====================================================
 137 +*/
 138 +static int __init bcm2835_cpufreq_module_init(void)
 139 +{
 140 +       print_debug("IN\n");
 141 +       return cpufreq_register_driver(&bcm2835_cpufreq_driver);
 142 +}
 143 +
 144 +/*
 145 + =============
 146 +  Module exit
 147 + =============
 148 +*/
 149 +static void __exit bcm2835_cpufreq_module_exit(void)
 150 +{
 151 +       print_debug("IN\n");
 152 +       cpufreq_unregister_driver(&bcm2835_cpufreq_driver);
 153 +       return;
 154 +}
 155 +
 156 +/*
 157 + ==============================================================
 158 +  Initialisation function sets up the CPU policy for first use
 159 + ==============================================================
 160 +*/
 161 +static int bcm2835_cpufreq_driver_init(struct cpufreq_policy *policy)
 162 +{
 163 +       /* measured value of how long it takes to change frequency */
 164 +       policy->cpuinfo.transition_latency = 355000; /* ns */
 165 +
 166 +       /* now find out what the maximum and minimum frequencies are */
 167 +       policy->min = policy->cpuinfo.min_freq = bcm2835_cpufreq_get_clock(VCMSG_GET_MIN_CLOCK);
 168 +       policy->max = policy->cpuinfo.max_freq = bcm2835_cpufreq_get_clock(VCMSG_GET_MAX_CLOCK);
 169 +       policy->cur = bcm2835_cpufreq_get_clock(VCMSG_GET_CLOCK_RATE);
 170 +
 171 +       print_info("min=%d max=%d cur=%d\n", policy->min, policy->max, policy->cur);
 172 +       return 0;
 173 +}
 174 +
 175 +/*
 176 + =================================================================================
 177 +  Target function chooses the most appropriate frequency from the table to enable
 178 + =================================================================================
 179 +*/
 180 +
 181 +static int bcm2835_cpufreq_driver_target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation)
 182 +{
 183 +       unsigned int target = target_freq;
 184 +       unsigned int cur = policy->cur;
 185 +       print_debug("%s: min=%d max=%d cur=%d target=%d\n",policy->governor->name,policy->min,policy->max,policy->cur,target_freq);
 186 +
 187 +       /* if we are above min and using ondemand, then just use max */
 188 +       if (strcmp("ondemand", policy->governor->name)==0 && target > policy->min)
 189 +               target = policy->max;
 190 +       /* if the frequency is the same, just quit */
 191 +       if (target == policy->cur)
 192 +               return 0;
 193 +
 194 +       /* otherwise were good to set the clock frequency */
 195 +       policy->cur = bcm2835_cpufreq_set_clock(policy->cur, target);
 196 +
 197 +       if (!policy->cur)
 198 +       {
 199 +               print_err("Error occurred setting a new frequency (%d)!\n", target);
 200 +               policy->cur = bcm2835_cpufreq_get_clock(VCMSG_GET_CLOCK_RATE);
 201 +               return -EINVAL;
 202 +       }
 203 +       print_debug("Freq %d->%d (min=%d max=%d target=%d request=%d)\n", cur, policy->cur, policy->min, policy->max, target_freq, target);
 204 +       return 0;
 205 +}
 206 +
 207 +static unsigned int bcm2835_cpufreq_driver_get(unsigned int cpu)
 208 +{
 209 +       unsigned int actual_rate = bcm2835_cpufreq_get_clock(VCMSG_GET_CLOCK_RATE);
 210 +       print_debug("cpu=%d\n", actual_rate);
 211 +       return actual_rate;
 212 +}
 213 +
 214 +/*
 215 + =================================================================================
 216 +  Verify ensures that when a policy is changed, it is suitable for the CPU to use
 217 + =================================================================================
 218 +*/
 219 +
 220 +static int bcm2835_cpufreq_driver_verify(struct cpufreq_policy *policy)
 221 +{
 222 +       print_info("switching to governor %s\n", policy->governor->name);
 223 +       return 0;
 224 +}
 225 +
 226 +
 227 +/* the CPUFreq driver */
 228 +static struct cpufreq_driver bcm2835_cpufreq_driver = {
 229 +               .name   = "BCM2835 CPUFreq",
 230 +               .owner  = THIS_MODULE,
 231 +               .init   = bcm2835_cpufreq_driver_init,
 232 +               .verify = bcm2835_cpufreq_driver_verify,
 233 +               .target = bcm2835_cpufreq_driver_target,
 234 +               .get    = bcm2835_cpufreq_driver_get
 235 +};
 236 +
 237 +MODULE_AUTHOR("Dorian Peake and Dom Cobley");
 238 +MODULE_DESCRIPTION("CPU frequency driver for BCM2835 chip");
 239 +MODULE_LICENSE("GPL");
 240 +
 241 +module_init(bcm2835_cpufreq_module_init);
 242 +module_exit(bcm2835_cpufreq_module_exit);
 243 +
 244 diff -urN linux-3.10/drivers/cpufreq/Kconfig.arm linux-rpi-3.10.y/drivers/cpufreq/Kconfig.arm
 245 --- linux-3.10/drivers/cpufreq/Kconfig.arm      2013-06-30 23:13:29.000000000 +0100
 246 +++ linux-rpi-3.10.y/drivers/cpufreq/Kconfig.arm        2013-07-06 15:25:50.000000000 +0100
 247 @@ -150,3 +150,11 @@
 248         default y
 249         help
 250           This adds the CPUFreq driver support for SPEAr SOCs.
 251 +
 252 +config ARM_BCM2835_CPUFREQ
 253 +       bool "BCM2835 Driver"
 254 +       default y
 255 +       help
 256 +         This adds the CPUFreq driver for BCM2835
 257 +
 258 +         If in doubt, say N.
 259 diff -urN linux-3.10/drivers/cpufreq/Makefile linux-rpi-3.10.y/drivers/cpufreq/Makefile
 260 --- linux-3.10/drivers/cpufreq/Makefile 2013-06-30 23:13:29.000000000 +0100
 261 +++ linux-rpi-3.10.y/drivers/cpufreq/Makefile   2013-07-06 15:25:50.000000000 +0100
 262 @@ -72,6 +72,7 @@
 263  obj-$(CONFIG_ARM_SA1110_CPUFREQ)       += sa1110-cpufreq.o
 264  obj-$(CONFIG_ARM_SPEAR_CPUFREQ)                += spear-cpufreq.o
 265  obj-$(CONFIG_ARCH_TEGRA)               += tegra-cpufreq.o
 266 +obj-$(CONFIG_ARM_BCM2835_CPUFREQ)      += bcm2835-cpufreq.o
 267
 268  ##################################################################################
 269  # PowerPC platform drivers