--- /dev/null
+From 21e72e1f417fe2c097fe8f8ba4963abdde88a6ca Mon Sep 17 00:00:00 2001
+From: popcornmix <popcornmix@gmail.com>
+Date: Wed, 3 Jul 2013 00:49:20 +0100
+Subject: [PATCH 044/127] Add cpufreq driver
+
+Signed-off-by: popcornmix <popcornmix@gmail.com>
+---
+ drivers/cpufreq/Kconfig.arm | 9 ++
+ drivers/cpufreq/Makefile | 1 +
+ drivers/cpufreq/bcm2835-cpufreq.c | 213 ++++++++++++++++++++++++++++++++++++++
+ 3 files changed, 223 insertions(+)
+ create mode 100644 drivers/cpufreq/bcm2835-cpufreq.c
+
+--- a/drivers/cpufreq/Kconfig.arm
++++ b/drivers/cpufreq/Kconfig.arm
+@@ -217,6 +217,15 @@ config ARM_SPEAR_CPUFREQ
+ help
+ This adds the CPUFreq driver support for SPEAr SOCs.
+
++config ARM_BCM2835_CPUFREQ
++ depends on RASPBERRYPI_FIRMWARE
++ bool "BCM2835 Driver"
++ default y
++ help
++ This adds the CPUFreq driver for BCM2835
++
++ If in doubt, say N.
++
+ config ARM_TEGRA20_CPUFREQ
+ bool "Tegra20 CPUFreq support"
+ depends on ARCH_TEGRA
+--- a/drivers/cpufreq/Makefile
++++ b/drivers/cpufreq/Makefile
+@@ -73,6 +73,7 @@ obj-$(CONFIG_ARM_SA1100_CPUFREQ) += sa11
+ obj-$(CONFIG_ARM_SA1110_CPUFREQ) += sa1110-cpufreq.o
+ obj-$(CONFIG_ARM_SCPI_CPUFREQ) += scpi-cpufreq.o
+ obj-$(CONFIG_ARM_SPEAR_CPUFREQ) += spear-cpufreq.o
++obj-$(CONFIG_ARM_BCM2835_CPUFREQ) += bcm2835-cpufreq.o
+ obj-$(CONFIG_ARM_TEGRA20_CPUFREQ) += tegra20-cpufreq.o
+ obj-$(CONFIG_ARM_TEGRA124_CPUFREQ) += tegra124-cpufreq.o
+ obj-$(CONFIG_ARM_VEXPRESS_SPC_CPUFREQ) += vexpress-spc-cpufreq.o
+--- /dev/null
++++ b/drivers/cpufreq/bcm2835-cpufreq.c
+@@ -0,0 +1,213 @@
++/*****************************************************************************
++* Copyright 2011 Broadcom Corporation. All rights reserved.
++*
++* Unless you and Broadcom execute a separate written software license
++* agreement governing use of this software, this software is licensed to you
++* under the terms of the GNU General Public License version 2, available at
++* http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
++*
++* Notwithstanding the above, under no circumstances may you combine this
++* software in any way with any other Broadcom software provided under a
++* license other than the GPL, without Broadcom's express prior written
++* consent.
++*****************************************************************************/
++
++/*****************************************************************************
++* FILENAME: bcm2835-cpufreq.h
++* DESCRIPTION: This driver dynamically manages the CPU Frequency of the ARM
++* processor. Messages are sent to Videocore either setting or requesting the
++* frequency of the ARM in order to match an appropiate frequency to the current
++* usage of the processor. The policy which selects the frequency to use is
++* defined in the kernel .config file, but can be changed during runtime.
++*****************************************************************************/
++
++/* ---------- INCLUDES ---------- */
++#include <linux/kernel.h>
++#include <linux/init.h>
++#include <linux/module.h>
++#include <linux/cpufreq.h>
++#include <soc/bcm2835/raspberrypi-firmware.h>
++
++/* ---------- DEFINES ---------- */
++/*#define CPUFREQ_DEBUG_ENABLE*/ /* enable debugging */
++#define MODULE_NAME "bcm2835-cpufreq"
++
++#define VCMSG_ID_ARM_CLOCK 0x000000003 /* Clock/Voltage ID's */
++
++/* debug printk macros */
++#ifdef CPUFREQ_DEBUG_ENABLE
++#define print_debug(fmt,...) pr_debug("%s:%s:%d: "fmt, MODULE_NAME, __func__, __LINE__, ##__VA_ARGS__)
++#else
++#define print_debug(fmt,...)
++#endif
++#define print_err(fmt,...) pr_err("%s:%s:%d: "fmt, MODULE_NAME, __func__,__LINE__, ##__VA_ARGS__)
++#define print_info(fmt,...) pr_info("%s: "fmt, MODULE_NAME, ##__VA_ARGS__)
++
++/* ---------- GLOBALS ---------- */
++static struct cpufreq_driver bcm2835_cpufreq_driver; /* the cpufreq driver global */
++
++static struct cpufreq_frequency_table bcm2835_freq_table[] = {
++ {0, 0, 0},
++ {0, 0, 0},
++ {0, 0, CPUFREQ_TABLE_END},
++};
++
++/*
++ ===============================================
++ clk_rate either gets or sets the clock rates.
++ ===============================================
++*/
++
++static int bcm2835_cpufreq_clock_property(u32 tag, u32 id, u32 *val)
++{
++ struct rpi_firmware *fw = rpi_firmware_get(NULL);
++ struct {
++ u32 id;
++ u32 val;
++ } packet;
++ int ret;
++
++ packet.id = id;
++ packet.val = *val;
++ ret = rpi_firmware_property(fw, tag, &packet, sizeof(packet));
++ if (ret)
++ return ret;
++
++ *val = packet.val;
++
++ return 0;
++}
++
++static uint32_t bcm2835_cpufreq_set_clock(int cur_rate, int arm_rate)
++{
++ u32 rate = arm_rate * 1000;
++ int ret;
++
++ ret = bcm2835_cpufreq_clock_property(RPI_FIRMWARE_SET_CLOCK_RATE, VCMSG_ID_ARM_CLOCK, &rate);
++ if (ret) {
++ print_err("Failed to set clock: %d (%d)\n", arm_rate, ret);
++ return 0;
++ }
++
++ rate /= 1000;
++ print_debug("Setting new frequency = %d -> %d (actual %d)\n", cur_rate, arm_rate, rate);
++
++ return rate;
++}
++
++static uint32_t bcm2835_cpufreq_get_clock(int tag)
++{
++ u32 rate;
++ int ret;
++
++ ret = bcm2835_cpufreq_clock_property(tag, VCMSG_ID_ARM_CLOCK, &rate);
++ if (ret) {
++ print_err("Failed to get clock (%d)\n", ret);
++ return 0;
++ }
++
++ rate /= 1000;
++ print_debug("%s frequency = %u\n",
++ tag == RPI_FIRMWARE_GET_CLOCK_RATE ? "Current":
++ tag == RPI_FIRMWARE_GET_MIN_CLOCK_RATE ? "Min":
++ tag == RPI_FIRMWARE_GET_MAX_CLOCK_RATE ? "Max":
++ "Unexpected", rate);
++
++ return rate;
++}
++
++/*
++ ====================================================
++ Module Initialisation registers the cpufreq driver
++ ====================================================
++*/
++static int __init bcm2835_cpufreq_module_init(void)
++{
++ print_debug("IN\n");
++ return cpufreq_register_driver(&bcm2835_cpufreq_driver);
++}
++
++/*
++ =============
++ Module exit
++ =============
++*/
++static void __exit bcm2835_cpufreq_module_exit(void)
++{
++ print_debug("IN\n");
++ cpufreq_unregister_driver(&bcm2835_cpufreq_driver);
++ return;
++}
++
++/*
++ ==============================================================
++ Initialisation function sets up the CPU policy for first use
++ ==============================================================
++*/
++static int bcm2835_cpufreq_driver_init(struct cpufreq_policy *policy)
++{
++ /* measured value of how long it takes to change frequency */
++ const unsigned int transition_latency = 355000; /* ns */
++
++ if (!rpi_firmware_get(NULL)) {
++ print_err("Firmware is not available\n");
++ return -ENODEV;
++ }
++
++ /* now find out what the maximum and minimum frequencies are */
++ bcm2835_freq_table[0].frequency = bcm2835_cpufreq_get_clock(RPI_FIRMWARE_GET_MIN_CLOCK_RATE);
++ bcm2835_freq_table[1].frequency = bcm2835_cpufreq_get_clock(RPI_FIRMWARE_GET_MAX_CLOCK_RATE);
++
++ print_info("min=%d max=%d\n", bcm2835_freq_table[0].frequency, bcm2835_freq_table[1].frequency);
++ return cpufreq_generic_init(policy, bcm2835_freq_table, transition_latency);
++}
++
++/*
++ =====================================================================
++ Target index function chooses the requested frequency from the table
++ =====================================================================
++*/
++
++static int bcm2835_cpufreq_driver_target_index(struct cpufreq_policy *policy, unsigned int state)
++{
++ unsigned int target_freq = bcm2835_freq_table[state].frequency;
++ unsigned int cur = bcm2835_cpufreq_set_clock(policy->cur, target_freq);
++
++ if (!cur)
++ {
++ print_err("Error occurred setting a new frequency (%d)\n", target_freq);
++ return -EINVAL;
++ }
++ print_debug("%s: %i: freq %d->%d\n", policy->governor->name, state, policy->cur, cur);
++ return 0;
++}
++
++/*
++ ======================================================
++ Get function returns the current frequency from table
++ ======================================================
++*/
++
++static unsigned int bcm2835_cpufreq_driver_get(unsigned int cpu)
++{
++ unsigned int actual_rate = bcm2835_cpufreq_get_clock(RPI_FIRMWARE_GET_CLOCK_RATE);
++ print_debug("cpu%d: freq=%d\n", cpu, actual_rate);
++ return actual_rate <= bcm2835_freq_table[0].frequency ? bcm2835_freq_table[0].frequency : bcm2835_freq_table[1].frequency;
++}
++
++/* the CPUFreq driver */
++static struct cpufreq_driver bcm2835_cpufreq_driver = {
++ .name = "BCM2835 CPUFreq",
++ .init = bcm2835_cpufreq_driver_init,
++ .verify = cpufreq_generic_frequency_table_verify,
++ .target_index = bcm2835_cpufreq_driver_target_index,
++ .get = bcm2835_cpufreq_driver_get,
++ .attr = cpufreq_generic_attr,
++};
++
++MODULE_AUTHOR("Dorian Peake and Dom Cobley");
++MODULE_DESCRIPTION("CPU frequency driver for BCM2835 chip");
++MODULE_LICENSE("GPL");
++
++module_init(bcm2835_cpufreq_module_init);
++module_exit(bcm2835_cpufreq_module_exit);
projects / openwrt.git / blobdiff