projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 8a67f0ef VK |
1 | /* |
| 2 | * Generic big.LITTLE CPUFreq Interface driver | |
| 3 | * | |
| 4 | * It provides necessary ops to arm_big_little cpufreq driver and gets | |
| 5 | * Frequency information from Device Tree. Freq table in DT must be in KHz. | |
| 6 | * | |
| 7 | * Copyright (C) 2013 Linaro. | |
| 8 | * Viresh Kumar <viresh.kumar@linaro.org> | |
| 9 | * | |
| 10 | * This program is free software; you can redistribute it and/or modify | |
| 11 | * it under the terms of the GNU General Public License version 2 as | |
| 12 | * published by the Free Software Foundation. | |
| 13 | * | |
| 14 | * This program is distributed "as is" WITHOUT ANY WARRANTY of any | |
| 15 | * kind, whether express or implied; without even the implied warranty | |
| 16 | * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 17 | * GNU General Public License for more details. | |
| 18 | */ | |
| 19 | ||
| 20 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
| 21 | ||
| 22 | #include <linux/cpufreq.h> | |
| 23 | #include <linux/device.h> | |
| 24 | #include <linux/export.h> | |
| 25 | #include <linux/module.h> | |
| 26 | #include <linux/of.h> | |
| 27 | #include <linux/opp.h> | |
| 28 | #include <linux/slab.h> | |
| 29 | #include <linux/types.h> | |
| 30 | #include "arm_big_little.h" | |
| 31 | ||
| 32 | static int dt_init_opp_table(struct device *cpu_dev) | |
| 33 | { | |
| 34 | struct device_node *np = NULL; | |
| 35 | int count = 0, ret; | |
| 36 | ||
| 37 | for_each_child_of_node(of_find_node_by_path("/cpus"), np) { | |
| 38 | if (count++ != cpu_dev->id) | |
| 39 | continue; | |
| 40 | if (!of_get_property(np, "operating-points", NULL)) | |
| 41 | return -ENODATA; | |
| 42 | ||
| 43 | cpu_dev->of_node = np; | |
| 44 | ||
| 45 | ret = of_init_opp_table(cpu_dev); | |
| 46 | if (ret) | |
| 47 | return ret; | |
| 48 | ||
| 49 | return 0; | |
| 50 | } | |
| 51 | ||
| 52 | return -ENODEV; | |
| 53 | } | |
| 54 | ||
| 55 | static int dt_get_transition_latency(struct device *cpu_dev) | |
| 56 | { | |
| 57 | struct device_node *np = NULL; | |
| 58 | u32 transition_latency = CPUFREQ_ETERNAL; | |
| 59 | int count = 0; | |
| 60 | ||
| 61 | for_each_child_of_node(of_find_node_by_path("/cpus"), np) { | |
| 62 | if (count++ != cpu_dev->id) | |
| 63 | continue; | |
| 64 | ||
| 65 | of_property_read_u32(np, "clock-latency", &transition_latency); | |
| 66 | return 0; | |
| 67 | } | |
| 68 | ||
| 69 | return -ENODEV; | |
| 70 | } | |
| 71 | ||
| 72 | static struct cpufreq_arm_bL_ops dt_bL_ops = { | |
| 73 | .name = "dt-bl", | |
| 74 | .get_transition_latency = dt_get_transition_latency, | |
| 75 | .init_opp_table = dt_init_opp_table, | |
| 76 | }; | |
| 77 | ||
| 78 | static int generic_bL_init(void) | |
| 79 | { | |
| 80 | return bL_cpufreq_register(&dt_bL_ops); | |
| 81 | } | |
| 82 | module_init(generic_bL_init); | |
| 83 | ||
| 84 | static void generic_bL_exit(void) | |
| 85 | { | |
| 86 | return bL_cpufreq_unregister(&dt_bL_ops); | |
| 87 | } | |
| 88 | module_exit(generic_bL_exit); | |
| 89 | ||
| 90 | MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>"); | |
| 91 | MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver via DT"); | |
| 92 | MODULE_LICENSE("GPL"); |