blob: 2c3b16fd3a01fc1c521f8201bd698dab2d6d1215 [file] [log] [blame]
Sudeep Holla8def3102015-03-30 10:59:52 +01001/*
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
21#include <linux/cpufreq.h>
22#include <linux/module.h>
23#include <linux/platform_device.h>
24#include <linux/pm_opp.h>
25#include <linux/scpi_protocol.h>
26#include <linux/types.h>
27
28#include "arm_big_little.h"
29
30static struct scpi_ops *scpi_ops;
31
32static struct scpi_dvfs_info *scpi_get_dvfs_info(struct device *cpu_dev)
33{
34 u8 domain = topology_physical_package_id(cpu_dev->id);
35
36 if (domain < 0)
37 return ERR_PTR(-EINVAL);
38 return scpi_ops->dvfs_get_info(domain);
39}
40
41static int scpi_opp_table_ops(struct device *cpu_dev, bool remove)
42{
43 int idx, ret = 0;
44 struct scpi_opp *opp;
45 struct scpi_dvfs_info *info = scpi_get_dvfs_info(cpu_dev);
46
47 if (IS_ERR(info))
48 return PTR_ERR(info);
49
50 if (!info->opps)
51 return -EIO;
52
53 for (opp = info->opps, idx = 0; idx < info->count; idx++, opp++) {
54 if (remove)
55 dev_pm_opp_remove(cpu_dev, opp->freq);
56 else
57 ret = dev_pm_opp_add(cpu_dev, opp->freq,
58 opp->m_volt * 1000);
59 if (ret) {
60 dev_warn(cpu_dev, "failed to add opp %uHz %umV\n",
61 opp->freq, opp->m_volt);
62 while (idx-- > 0)
63 dev_pm_opp_remove(cpu_dev, (--opp)->freq);
64 return ret;
65 }
66 }
67 return ret;
68}
69
70static int scpi_get_transition_latency(struct device *cpu_dev)
71{
72 struct scpi_dvfs_info *info = scpi_get_dvfs_info(cpu_dev);
73
74 if (IS_ERR(info))
75 return PTR_ERR(info);
76 return info->latency;
77}
78
79static int scpi_init_opp_table(struct device *cpu_dev)
80{
81 return scpi_opp_table_ops(cpu_dev, false);
82}
83
84static void scpi_free_opp_table(struct device *cpu_dev)
85{
86 scpi_opp_table_ops(cpu_dev, true);
87}
88
89static struct cpufreq_arm_bL_ops scpi_cpufreq_ops = {
90 .name = "scpi",
91 .get_transition_latency = scpi_get_transition_latency,
92 .init_opp_table = scpi_init_opp_table,
93 .free_opp_table = scpi_free_opp_table,
94};
95
96static int scpi_cpufreq_probe(struct platform_device *pdev)
97{
98 scpi_ops = get_scpi_ops();
99 if (!scpi_ops)
100 return -EIO;
101
102 return bL_cpufreq_register(&scpi_cpufreq_ops);
103}
104
105static int scpi_cpufreq_remove(struct platform_device *pdev)
106{
107 bL_cpufreq_unregister(&scpi_cpufreq_ops);
108 scpi_ops = NULL;
109 return 0;
110}
111
112static struct platform_driver scpi_cpufreq_platdrv = {
113 .driver = {
114 .name = "scpi-cpufreq",
115 .owner = THIS_MODULE,
116 },
117 .probe = scpi_cpufreq_probe,
118 .remove = scpi_cpufreq_remove,
119};
120module_platform_driver(scpi_cpufreq_platdrv);
121
122MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
123MODULE_DESCRIPTION("ARM SCPI CPUFreq interface driver");
124MODULE_LICENSE("GPL v2");