diff options
Diffstat (limited to 'drivers/cpufreq/vexpress_big_little.c')
-rw-r--r-- | drivers/cpufreq/vexpress_big_little.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/drivers/cpufreq/vexpress_big_little.c b/drivers/cpufreq/vexpress_big_little.c new file mode 100644 index 000000000000..1abb883c051b --- /dev/null +++ b/drivers/cpufreq/vexpress_big_little.c @@ -0,0 +1,86 @@ +/* + * Vexpress big.LITTLE CPUFreq Interface driver + * + * It provides necessary ops to arm_big_little cpufreq driver and gets + * Frequency information from Device Tree. Freq table in DT must be in KHz. + * + * Copyright (C) 2013 Linaro. + * Viresh Kumar <viresh.kumar@linaro.org> + * + * 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/export.h> +#include <linux/opp.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/vexpress.h> +#include "arm_big_little.h" + +static int vexpress_init_opp_table(struct device *cpu_dev) +{ + int i = -1, count, cluster = cpu_to_cluster(cpu_dev->id); + u32 *table; + int ret; + + count = vexpress_spc_get_freq_table(cluster, &table); + if (!table || !count) { + pr_err("SPC controller returned invalid freq table"); + return -EINVAL; + } + + while (++i < count) { + /* FIXME: Voltage value */ + ret = opp_add(cpu_dev, table[i] * 1000, 900000); + if (ret) { + dev_warn(cpu_dev, "%s: Failed to add OPP %d, err: %d\n", + __func__, table[i] * 1000, ret); + return ret; + } + } + + return 0; +} + +static int vexpress_get_transition_latency(struct device *cpu_dev) +{ + /* 1 ms */ + return 1000000; +} + +static struct cpufreq_arm_bL_ops vexpress_bL_ops = { + .name = "vexpress-bL", + .get_transition_latency = vexpress_get_transition_latency, + .init_opp_table = vexpress_init_opp_table, +}; + +static int vexpress_bL_init(void) +{ + if (!vexpress_spc_check_loaded()) { + pr_info("%s: No SPC found\n", __func__); + return -ENOENT; + } + + return bL_cpufreq_register(&vexpress_bL_ops); +} +module_init(vexpress_bL_init); + +static void vexpress_bL_exit(void) +{ + return bL_cpufreq_unregister(&vexpress_bL_ops); +} +module_exit(vexpress_bL_exit); + +MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>"); +MODULE_DESCRIPTION("ARM Vexpress big LITTLE cpufreq driver"); +MODULE_LICENSE("GPL"); |