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8def3103 SH |
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 | ||
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 | ||
30 | static struct scpi_ops *scpi_ops; | |
31 | ||
32 | static struct scpi_dvfs_info *scpi_get_dvfs_info(struct device *cpu_dev) | |
33 | { | |
a7def561 | 34 | int domain = topology_physical_package_id(cpu_dev->id); |
8def3103 SH |
35 | |
36 | if (domain < 0) | |
37 | return ERR_PTR(-EINVAL); | |
38 | return scpi_ops->dvfs_get_info(domain); | |
39 | } | |
40 | ||
41 | static 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 | ||
70 | static 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 | ||
79 | static int scpi_init_opp_table(struct device *cpu_dev) | |
80 | { | |
81 | return scpi_opp_table_ops(cpu_dev, false); | |
82 | } | |
83 | ||
84 | static void scpi_free_opp_table(struct device *cpu_dev) | |
85 | { | |
86 | scpi_opp_table_ops(cpu_dev, true); | |
87 | } | |
88 | ||
89 | static 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 | ||
96 | static 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 | ||
105 | static 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 | ||
112 | static 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 | }; | |
120 | module_platform_driver(scpi_cpufreq_platdrv); | |
121 | ||
122 | MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>"); | |
123 | MODULE_DESCRIPTION("ARM SCPI CPUFreq interface driver"); | |
124 | MODULE_LICENSE("GPL v2"); |