Sudeep Holla | 8def310 | 2015-03-30 10:59:52 +0100 | [diff] [blame] | 1 | /* |
| 2 | * System Control and Power Interface (SCPI) based CPUFreq Interface driver |
| 3 | * |
| 4 | * It provides necessary ops to arm_big_little cpufreq driver. |
| 5 | * |
| 6 | * Copyright (C) 2015 ARM Ltd. |
| 7 | * Sudeep Holla <sudeep.holla@arm.com> |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License version 2 as |
| 11 | * published by the Free Software Foundation. |
| 12 | * |
| 13 | * This program is distributed "as is" WITHOUT ANY WARRANTY of any |
| 14 | * kind, whether express or implied; without even the implied warranty |
| 15 | * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | */ |
| 18 | |
| 19 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 20 | |
Sudeep Holla | d9975b0 | 2016-05-03 15:05:05 +0100 | [diff] [blame] | 21 | #include <linux/cpu.h> |
Sudeep Holla | 8def310 | 2015-03-30 10:59:52 +0100 | [diff] [blame] | 22 | #include <linux/cpufreq.h> |
| 23 | #include <linux/module.h> |
| 24 | #include <linux/platform_device.h> |
| 25 | #include <linux/pm_opp.h> |
| 26 | #include <linux/scpi_protocol.h> |
| 27 | #include <linux/types.h> |
| 28 | |
| 29 | #include "arm_big_little.h" |
| 30 | |
| 31 | static struct scpi_ops *scpi_ops; |
| 32 | |
| 33 | static struct scpi_dvfs_info *scpi_get_dvfs_info(struct device *cpu_dev) |
| 34 | { |
Dan Carpenter | a7def56 | 2015-12-15 11:16:44 +0000 | [diff] [blame] | 35 | int domain = topology_physical_package_id(cpu_dev->id); |
Sudeep Holla | 8def310 | 2015-03-30 10:59:52 +0100 | [diff] [blame] | 36 | |
| 37 | if (domain < 0) |
| 38 | return ERR_PTR(-EINVAL); |
| 39 | return scpi_ops->dvfs_get_info(domain); |
| 40 | } |
| 41 | |
Sudeep Holla | 8def310 | 2015-03-30 10:59:52 +0100 | [diff] [blame] | 42 | static int scpi_get_transition_latency(struct device *cpu_dev) |
| 43 | { |
| 44 | struct scpi_dvfs_info *info = scpi_get_dvfs_info(cpu_dev); |
| 45 | |
| 46 | if (IS_ERR(info)) |
| 47 | return PTR_ERR(info); |
| 48 | return info->latency; |
| 49 | } |
| 50 | |
Sudeep Holla | d9975b0 | 2016-05-03 15:05:05 +0100 | [diff] [blame] | 51 | static int scpi_init_opp_table(const struct cpumask *cpumask) |
Sudeep Holla | 8def310 | 2015-03-30 10:59:52 +0100 | [diff] [blame] | 52 | { |
Sudeep Holla | d9975b0 | 2016-05-03 15:05:05 +0100 | [diff] [blame] | 53 | int idx, ret; |
| 54 | struct scpi_opp *opp; |
| 55 | struct device *cpu_dev = get_cpu_device(cpumask_first(cpumask)); |
| 56 | struct scpi_dvfs_info *info = scpi_get_dvfs_info(cpu_dev); |
Sudeep Holla | 8def310 | 2015-03-30 10:59:52 +0100 | [diff] [blame] | 57 | |
Sudeep Holla | d9975b0 | 2016-05-03 15:05:05 +0100 | [diff] [blame] | 58 | if (IS_ERR(info)) |
| 59 | return PTR_ERR(info); |
| 60 | |
| 61 | if (!info->opps) |
| 62 | return -EIO; |
| 63 | |
| 64 | for (opp = info->opps, idx = 0; idx < info->count; idx++, opp++) { |
| 65 | ret = dev_pm_opp_add(cpu_dev, opp->freq, opp->m_volt * 1000); |
| 66 | if (ret) { |
| 67 | dev_warn(cpu_dev, "failed to add opp %uHz %umV\n", |
| 68 | opp->freq, opp->m_volt); |
| 69 | while (idx-- > 0) |
| 70 | dev_pm_opp_remove(cpu_dev, (--opp)->freq); |
| 71 | return ret; |
| 72 | } |
| 73 | } |
| 74 | |
| 75 | ret = dev_pm_opp_set_sharing_cpus(cpu_dev, cpumask); |
| 76 | if (ret) |
| 77 | dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n", |
| 78 | __func__, ret); |
| 79 | return ret; |
Sudeep Holla | 8def310 | 2015-03-30 10:59:52 +0100 | [diff] [blame] | 80 | } |
| 81 | |
| 82 | static struct cpufreq_arm_bL_ops scpi_cpufreq_ops = { |
| 83 | .name = "scpi", |
| 84 | .get_transition_latency = scpi_get_transition_latency, |
| 85 | .init_opp_table = scpi_init_opp_table, |
Sudeep Holla | d9975b0 | 2016-05-03 15:05:05 +0100 | [diff] [blame] | 86 | .free_opp_table = dev_pm_opp_cpumask_remove_table, |
Sudeep Holla | 8def310 | 2015-03-30 10:59:52 +0100 | [diff] [blame] | 87 | }; |
| 88 | |
| 89 | static int scpi_cpufreq_probe(struct platform_device *pdev) |
| 90 | { |
| 91 | scpi_ops = get_scpi_ops(); |
| 92 | if (!scpi_ops) |
| 93 | return -EIO; |
| 94 | |
| 95 | return bL_cpufreq_register(&scpi_cpufreq_ops); |
| 96 | } |
| 97 | |
| 98 | static int scpi_cpufreq_remove(struct platform_device *pdev) |
| 99 | { |
| 100 | bL_cpufreq_unregister(&scpi_cpufreq_ops); |
| 101 | scpi_ops = NULL; |
| 102 | return 0; |
| 103 | } |
| 104 | |
| 105 | static struct platform_driver scpi_cpufreq_platdrv = { |
| 106 | .driver = { |
| 107 | .name = "scpi-cpufreq", |
| 108 | .owner = THIS_MODULE, |
| 109 | }, |
| 110 | .probe = scpi_cpufreq_probe, |
| 111 | .remove = scpi_cpufreq_remove, |
| 112 | }; |
| 113 | module_platform_driver(scpi_cpufreq_platdrv); |
| 114 | |
| 115 | MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>"); |
| 116 | MODULE_DESCRIPTION("ARM SCPI CPUFreq interface driver"); |
| 117 | MODULE_LICENSE("GPL v2"); |