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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 | ||
d9975b0b | 21 | #include <linux/cpu.h> |
8def3103 SH |
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 | { | |
a7def561 | 35 | int domain = topology_physical_package_id(cpu_dev->id); |
8def3103 SH |
36 | |
37 | if (domain < 0) | |
38 | return ERR_PTR(-EINVAL); | |
39 | return scpi_ops->dvfs_get_info(domain); | |
40 | } | |
41 | ||
d9975b0b | 42 | static int scpi_get_transition_latency(struct device *cpu_dev) |
8def3103 | 43 | { |
d9975b0b SH |
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 | ||
51 | static int scpi_init_opp_table(const struct cpumask *cpumask) | |
52 | { | |
53 | int idx, ret; | |
8def3103 | 54 | struct scpi_opp *opp; |
d9975b0b | 55 | struct device *cpu_dev = get_cpu_device(cpumask_first(cpumask)); |
8def3103 SH |
56 | struct scpi_dvfs_info *info = scpi_get_dvfs_info(cpu_dev); |
57 | ||
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++) { | |
d9975b0b | 65 | ret = dev_pm_opp_add(cpu_dev, opp->freq, opp->m_volt * 1000); |
8def3103 SH |
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 | } | |
8def3103 | 74 | |
d9975b0b SH |
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; | |
8def3103 SH |
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, | |
d9975b0b | 86 | .free_opp_table = dev_pm_opp_cpumask_remove_table, |
8def3103 SH |
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"); |