+++ /dev/null
-From ce9f1474536ee0a348a6edaefe36c537d76e8f1b Mon Sep 17 00:00:00 2001
-From: popcornmix <popcornmix@gmail.com>
-Date: Wed, 3 Jul 2013 00:49:20 +0100
-Subject: [PATCH 017/222] Add cpufreq driver
-
-Signed-off-by: popcornmix <popcornmix@gmail.com>
----
- drivers/cpufreq/Kconfig.arm | 9 ++
- drivers/cpufreq/Makefile | 1 +
- drivers/cpufreq/bcm2835-cpufreq.c | 224 ++++++++++++++++++++++++++++++++++++++
- 3 files changed, 234 insertions(+)
- create mode 100644 drivers/cpufreq/bcm2835-cpufreq.c
-
---- a/drivers/cpufreq/Kconfig.arm
-+++ b/drivers/cpufreq/Kconfig.arm
-@@ -258,6 +258,15 @@ config ARM_SPEAR_CPUFREQ
- help
- This adds the CPUFreq driver support for SPEAr SOCs.
-
-+config ARM_BCM2835_CPUFREQ
-+ depends on BCM2708_MBOX
-+ bool "BCM2835 Driver"
-+ default y
-+ help
-+ This adds the CPUFreq driver for BCM2835
-+
-+ If in doubt, say N.
-+
- config ARM_TEGRA_CPUFREQ
- bool "TEGRA CPUFreq support"
- depends on ARCH_TEGRA
---- a/drivers/cpufreq/Makefile
-+++ b/drivers/cpufreq/Makefile
-@@ -77,6 +77,7 @@ obj-$(CONFIG_ARM_S5PV210_CPUFREQ) += s5p
- obj-$(CONFIG_ARM_SA1100_CPUFREQ) += sa1100-cpufreq.o
- obj-$(CONFIG_ARM_SA1110_CPUFREQ) += sa1110-cpufreq.o
- obj-$(CONFIG_ARM_SPEAR_CPUFREQ) += spear-cpufreq.o
-+obj-$(CONFIG_ARM_BCM2835_CPUFREQ) += bcm2835-cpufreq.o
- obj-$(CONFIG_ARM_TEGRA_CPUFREQ) += tegra-cpufreq.o
- obj-$(CONFIG_ARM_VEXPRESS_SPC_CPUFREQ) += vexpress-spc-cpufreq.o
-
---- /dev/null
-+++ b/drivers/cpufreq/bcm2835-cpufreq.c
-@@ -0,0 +1,224 @@
-+/*****************************************************************************
-+* 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 <linux/platform_data/mailbox-bcm2708.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__)
-+
-+/* tag part of the message */
-+struct vc_msg_tag {
-+ uint32_t tag_id; /* the message id */
-+ uint32_t buffer_size; /* size of the buffer (which in this case is always 8 bytes) */
-+ uint32_t data_size; /* amount of data being sent or received */
-+ uint32_t dev_id; /* the ID of the clock/voltage to get or set */
-+ uint32_t val; /* the value (e.g. rate (in Hz)) to set */
-+};
-+
-+/* message structure to be sent to videocore */
-+struct vc_msg {
-+ uint32_t msg_size; /* simply, sizeof(struct vc_msg) */
-+ uint32_t request_code; /* holds various information like the success and number of bytes returned (refer to mailboxes wiki) */
-+ struct vc_msg_tag tag; /* the tag structure above to make */
-+ uint32_t end_tag; /* an end identifier, should be set to NULL */
-+};
-+
-+/* ---------- 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 uint32_t bcm2835_cpufreq_set_clock(int cur_rate, int arm_rate)
-+{
-+ int s, actual_rate=0;
-+ struct vc_msg msg;
-+
-+ /* wipe all previous message data */
-+ memset(&msg, 0, sizeof msg);
-+
-+ msg.msg_size = sizeof msg;
-+
-+ msg.tag.tag_id = VCMSG_SET_CLOCK_RATE;
-+ msg.tag.buffer_size = 8;
-+ msg.tag.data_size = 8; /* we're sending the clock ID and the new rates which is a total of 2 words */
-+ msg.tag.dev_id = VCMSG_ID_ARM_CLOCK;
-+ msg.tag.val = arm_rate * 1000;
-+
-+ /* send the message */
-+ s = bcm_mailbox_property(&msg, sizeof msg);
-+
-+ /* check if it was all ok and return the rate in KHz */
-+ if (s == 0 && (msg.request_code & 0x80000000))
-+ actual_rate = msg.tag.val/1000;
-+
-+ print_debug("Setting new frequency = %d -> %d (actual %d)\n", cur_rate, arm_rate, actual_rate);
-+ return actual_rate;
-+}
-+
-+static uint32_t bcm2835_cpufreq_get_clock(int tag)
-+{
-+ int s;
-+ int arm_rate = 0;
-+ struct vc_msg msg;
-+
-+ /* wipe all previous message data */
-+ memset(&msg, 0, sizeof msg);
-+
-+ msg.msg_size = sizeof msg;
-+ msg.tag.tag_id = tag;
-+ msg.tag.buffer_size = 8;
-+ msg.tag.data_size = 4; /* we're just sending the clock ID which is one word long */
-+ msg.tag.dev_id = VCMSG_ID_ARM_CLOCK;
-+
-+ /* send the message */
-+ s = bcm_mailbox_property(&msg, sizeof msg);
-+
-+ /* check if it was all ok and return the rate in KHz */
-+ if (s == 0 && (msg.request_code & 0x80000000))
-+ arm_rate = msg.tag.val/1000;
-+
-+ print_debug("%s frequency = %d\n",
-+ tag == VCMSG_GET_CLOCK_RATE ? "Current":
-+ tag == VCMSG_GET_MIN_CLOCK ? "Min":
-+ tag == VCMSG_GET_MAX_CLOCK ? "Max":
-+ "Unexpected", arm_rate);
-+
-+ return arm_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 */
-+
-+ /* now find out what the maximum and minimum frequencies are */
-+ bcm2835_freq_table[0].frequency = bcm2835_cpufreq_get_clock(VCMSG_GET_MIN_CLOCK);
-+ bcm2835_freq_table[1].frequency = bcm2835_cpufreq_get_clock(VCMSG_GET_MAX_CLOCK);
-+
-+ 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(VCMSG_GET_CLOCK_RATE);
-+ print_debug("%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);
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