diff options
Diffstat (limited to 'target/linux/brcm2708/patches-4.14/950-0049-Add-cpufreq-driver.patch')
| -rw-r--r-- | target/linux/brcm2708/patches-4.14/950-0049-Add-cpufreq-driver.patch | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.14/950-0049-Add-cpufreq-driver.patch b/target/linux/brcm2708/patches-4.14/950-0049-Add-cpufreq-driver.patch new file mode 100644 index 0000000000..4886d28ffe --- /dev/null +++ b/target/linux/brcm2708/patches-4.14/950-0049-Add-cpufreq-driver.patch @@ -0,0 +1,259 @@ +From 1466a5baed955602aa2f5283a41b3988794d3caf Mon Sep 17 00:00:00 2001 +From: popcornmix <popcornmix@gmail.com> +Date: Wed, 3 Jul 2013 00:49:20 +0100 +Subject: [PATCH 049/454] Add cpufreq driver + +Signed-off-by: popcornmix <popcornmix@gmail.com> + +bcm2835-cpufreq: Change licence to GPLv2 + +Signed-off-by: Eben Upton <eben.upton@broadcom.com> +Signed-off-by: Dom Cobley <dom@raspberrypi.com> +--- + drivers/cpufreq/Kconfig.arm | 9 ++ + drivers/cpufreq/Makefile | 1 + + drivers/cpufreq/bcm2835-cpufreq.c | 210 ++++++++++++++++++++++++++++++ + 3 files changed, 220 insertions(+) + create mode 100644 drivers/cpufreq/bcm2835-cpufreq.c + +--- a/drivers/cpufreq/Kconfig.arm ++++ b/drivers/cpufreq/Kconfig.arm +@@ -237,6 +237,15 @@ config ARM_TANGO_CPUFREQ + depends on CPUFREQ_DT && ARCH_TANGO + default y + ++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 +@@ -76,6 +76,7 @@ obj-$(CONFIG_ARM_SCPI_CPUFREQ) += scpi- + obj-$(CONFIG_ARM_SPEAR_CPUFREQ) += spear-cpufreq.o + obj-$(CONFIG_ARM_STI_CPUFREQ) += sti-cpufreq.o + obj-$(CONFIG_ARM_TANGO_CPUFREQ) += tango-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_TEGRA186_CPUFREQ) += tegra186-cpufreq.o +--- /dev/null ++++ b/drivers/cpufreq/bcm2835-cpufreq.c +@@ -0,0 +1,210 @@ ++/* ++ * Copyright 2011 Broadcom Corporation. ++ * ++ * This program is free software; you can redistribute it and/or ++ * modify it under the terms of the GNU General Public License ++ * as published by the Free Software Foundation; version 2 ++ * of the License. ++ * ++ * 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 unsigned int min_frequency, max_frequency; ++static struct cpufreq_frequency_table bcm2835_freq_table[3]; ++ ++/* ++ =============================================== ++ 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 */ ++ min_frequency = bcm2835_cpufreq_get_clock(RPI_FIRMWARE_GET_MIN_CLOCK_RATE); ++ max_frequency = bcm2835_cpufreq_get_clock(RPI_FIRMWARE_GET_MAX_CLOCK_RATE); ++ ++ if (min_frequency == max_frequency) { ++ bcm2835_freq_table[0].frequency = min_frequency; ++ bcm2835_freq_table[1].frequency = CPUFREQ_TABLE_END; ++ } else { ++ bcm2835_freq_table[0].frequency = min_frequency; ++ bcm2835_freq_table[1].frequency = max_frequency; ++ bcm2835_freq_table[2].frequency = CPUFREQ_TABLE_END; ++ } ++ ++ print_info("min=%d max=%d\n", min_frequency, max_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 = state == 0 ? min_frequency : max_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 <= min_frequency ? min_frequency : max_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); |