diff options
Diffstat (limited to 'drivers/cpufreq/scpi-cpufreq.c')
-rw-r--r-- | drivers/cpufreq/scpi-cpufreq.c | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c new file mode 100644 index 000000000000..6311feb52a07 --- /dev/null +++ b/drivers/cpufreq/scpi-cpufreq.c @@ -0,0 +1,103 @@ +/* + * SCPI CPUFreq Interface driver + * + * It provides necessary ops to arm_big_little cpufreq driver. + * + * Copyright (C) 2015 ARM Ltd. + * Sudeep Holla <sudeep.holla@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/opp.h> +#include <linux/scpi_protocol.h> +#include <linux/types.h> + +#include "arm_big_little.h" + +static struct scpi_ops *scpi_ops; + +static int scpi_init_opp_table(struct device *cpu_dev) +{ + u8 domain = topology_physical_package_id(cpu_dev->id); + struct scpi_dvfs_info *info; + struct scpi_opp *opp; + int idx, ret = 0; + + if ((opp_get_opp_count(cpu_dev)) > 0) + return 0; + info = scpi_ops->dvfs_get_info(domain); + if (IS_ERR(info)) + return PTR_ERR(info); + + opp = info->opps; + if (!opp) + return -EIO; + + for (idx = 0; idx < info->count; idx++, opp++) { + ret = opp_add(cpu_dev, opp->freq, opp->m_volt * 1000); + if (ret) { + dev_warn(cpu_dev, "failed to add opp %uHz %umV\n", + opp->freq, opp->m_volt); + return ret; + } + } + return ret; +} + +static int scpi_get_transition_latency(struct device *cpu_dev) +{ + u8 domain = topology_physical_package_id(cpu_dev->id); + struct scpi_dvfs_info *info; + + info = scpi_ops->dvfs_get_info(domain); + if (IS_ERR(info)) + return PTR_ERR(info); + + return info->latency; +} + +static struct cpufreq_arm_bL_ops scpi_cpufreq_ops = { + .name = "scpi", + .get_transition_latency = scpi_get_transition_latency, + .init_opp_table = scpi_init_opp_table, +}; + +static int scpi_cpufreq_probe(struct platform_device *pdev) +{ + scpi_ops = get_scpi_ops(); + if (!scpi_ops) + return -EIO; + + return bL_cpufreq_register(&scpi_cpufreq_ops); +} + +static int scpi_cpufreq_remove(struct platform_device *pdev) +{ + bL_cpufreq_unregister(&scpi_cpufreq_ops); + return 0; +} + +static struct platform_driver scpi_cpufreq_platdrv = { + .driver = { + .name = "scpi-cpufreq", + .owner = THIS_MODULE, + }, + .probe = scpi_cpufreq_probe, + .remove = scpi_cpufreq_remove, +}; +module_platform_driver(scpi_cpufreq_platdrv); + +MODULE_LICENSE("GPL"); |