From 47ac9aa165540b43deb3582f186073884de1cf3b Mon Sep 17 00:00:00 2001 From: Sudeep KarkadaNagesha Date: Tue, 29 Oct 2013 12:18:39 +0000 Subject: 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 Acked-by: Nicolas Pitre Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/vexpress-spc-cpufreq.c | 70 ++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 drivers/cpufreq/vexpress-spc-cpufreq.c (limited to 'drivers/cpufreq/vexpress-spc-cpufreq.c') diff --git a/drivers/cpufreq/vexpress-spc-cpufreq.c b/drivers/cpufreq/vexpress-spc-cpufreq.c new file mode 100644 index 00000000000..7f7c9c01b44 --- /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 + * + * 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 +#include +#include +#include +#include + +#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"); -- cgit v1.2.3-70-g09d2