You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
259 lines
8.0 KiB
259 lines
8.0 KiB
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);
|
|
|