diff options
author | Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> | 2013-10-29 12:18:39 +0000 |
---|---|---|
committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-10-30 00:48:26 +0100 |
commit | 47ac9aa165540b43deb3582f186073884de1cf3b (patch) | |
tree | b191ae170496778588b34c8150015a7ac353d6a1 /drivers | |
parent | 4d910d5bb56c870e5a737b71d4130ec38dc4faea (diff) | |
download | linux-47ac9aa165540b43deb3582f186073884de1cf3b.tar.gz linux-47ac9aa165540b43deb3582f186073884de1cf3b.tar.bz2 linux-47ac9aa165540b43deb3582f186073884de1cf3b.zip |
cpufreq: arm_big_little: add vexpress SPC interface driver
The TC2(i.e. CA15_A7) Versatile Express has external Cortex M3 based
power controller which is responsible for CPU DVFS and SPC provides
the interface for the same.
This patch adds a tiny interface driver to check if OPPs are
initialised by SPC platform code and register the arm_big_little
cpufreq driver.
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/cpufreq/Kconfig.arm | 8 | ||||
-rw-r--r-- | drivers/cpufreq/Makefile | 1 | ||||
-rw-r--r-- | drivers/cpufreq/vexpress-spc-cpufreq.c | 70 |
3 files changed, 79 insertions, 0 deletions
diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm index 701ec95ce954..ce52ed949249 100644 --- a/drivers/cpufreq/Kconfig.arm +++ b/drivers/cpufreq/Kconfig.arm @@ -224,3 +224,11 @@ config ARM_TEGRA_CPUFREQ default y help This adds the CPUFreq driver support for TEGRA SOCs. + +config ARM_VEXPRESS_SPC_CPUFREQ + tristate "Versatile Express SPC based CPUfreq driver" + select ARM_BIG_LITTLE_CPUFREQ + depends on ARCH_VEXPRESS_SPC + help + This add the CPUfreq driver support for Versatile Express + big.LITTLE platforms using SPC for power management. diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile index b7948bbbbf1f..74945652dd7a 100644 --- a/drivers/cpufreq/Makefile +++ b/drivers/cpufreq/Makefile @@ -74,6 +74,7 @@ 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_TEGRA_CPUFREQ) += tegra-cpufreq.o +obj-$(CONFIG_ARM_VEXPRESS_SPC_CPUFREQ) += vexpress-spc-cpufreq.o ################################################################################## # PowerPC platform drivers diff --git a/drivers/cpufreq/vexpress-spc-cpufreq.c b/drivers/cpufreq/vexpress-spc-cpufreq.c new file mode 100644 index 000000000000..7f7c9c01b44e --- /dev/null +++ b/drivers/cpufreq/vexpress-spc-cpufreq.c @@ -0,0 +1,70 @@ +/* + * Versatile Express SPC CPUFreq Interface driver + * + * It provides necessary ops to arm_big_little cpufreq driver. + * + * Copyright (C) 2013 ARM Ltd. + * Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/cpufreq.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/pm_opp.h> +#include <linux/types.h> + +#include "arm_big_little.h" + +static int ve_spc_init_opp_table(struct device *cpu_dev) +{ + /* + * platform specific SPC code must initialise the opp table + * so just check if the OPP count is non-zero + */ + return dev_pm_opp_get_opp_count(cpu_dev) <= 0; +} + +static int ve_spc_get_transition_latency(struct device *cpu_dev) +{ + return 1000000; /* 1 ms */ +} + +static struct cpufreq_arm_bL_ops ve_spc_cpufreq_ops = { + .name = "vexpress-spc", + .get_transition_latency = ve_spc_get_transition_latency, + .init_opp_table = ve_spc_init_opp_table, +}; + +static int ve_spc_cpufreq_probe(struct platform_device *pdev) +{ + return bL_cpufreq_register(&ve_spc_cpufreq_ops); +} + +static int ve_spc_cpufreq_remove(struct platform_device *pdev) +{ + bL_cpufreq_unregister(&ve_spc_cpufreq_ops); + return 0; +} + +static struct platform_driver ve_spc_cpufreq_platdrv = { + .driver = { + .name = "vexpress-spc-cpufreq", + .owner = THIS_MODULE, + }, + .probe = ve_spc_cpufreq_probe, + .remove = ve_spc_cpufreq_remove, +}; +module_platform_driver(ve_spc_cpufreq_platdrv); + +MODULE_LICENSE("GPL"); |