1 /* 2 * Generic OPP helper interface for CPU device 3 * 4 * Copyright (C) 2009-2014 Texas Instruments Incorporated. 5 * Nishanth Menon 6 * Romit Dasgupta 7 * Kevin Hilman 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 14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 15 16 #include <linux/cpu.h> 17 #include <linux/cpufreq.h> 18 #include <linux/err.h> 19 #include <linux/errno.h> 20 #include <linux/export.h> 21 #include <linux/slab.h> 22 23 #include "opp.h" 24 25 #ifdef CONFIG_CPU_FREQ 26 27 /** 28 * dev_pm_opp_init_cpufreq_table() - create a cpufreq table for a device 29 * @dev: device for which we do this operation 30 * @table: Cpufreq table returned back to caller 31 * 32 * Generate a cpufreq table for a provided device- this assumes that the 33 * opp table is already initialized and ready for usage. 34 * 35 * This function allocates required memory for the cpufreq table. It is 36 * expected that the caller does the required maintenance such as freeing 37 * the table as required. 38 * 39 * Returns -EINVAL for bad pointers, -ENODEV if the device is not found, -ENOMEM 40 * if no memory available for the operation (table is not populated), returns 0 41 * if successful and table is populated. 42 * 43 * WARNING: It is important for the callers to ensure refreshing their copy of 44 * the table if any of the mentioned functions have been invoked in the interim. 45 */ 46 int dev_pm_opp_init_cpufreq_table(struct device *dev, 47 struct cpufreq_frequency_table **table) 48 { 49 struct dev_pm_opp *opp; 50 struct cpufreq_frequency_table *freq_table = NULL; 51 int i, max_opps, ret = 0; 52 unsigned long rate; 53 54 max_opps = dev_pm_opp_get_opp_count(dev); 55 if (max_opps <= 0) 56 return max_opps ? max_opps : -ENODATA; 57 58 freq_table = kcalloc((max_opps + 1), sizeof(*freq_table), GFP_ATOMIC); 59 if (!freq_table) 60 return -ENOMEM; 61 62 for (i = 0, rate = 0; i < max_opps; i++, rate++) { 63 /* find next rate */ 64 opp = dev_pm_opp_find_freq_ceil(dev, &rate); 65 if (IS_ERR(opp)) { 66 ret = PTR_ERR(opp); 67 goto out; 68 } 69 freq_table[i].driver_data = i; 70 freq_table[i].frequency = rate / 1000; 71 72 /* Is Boost/turbo opp ? */ 73 if (dev_pm_opp_is_turbo(opp)) 74 freq_table[i].flags = CPUFREQ_BOOST_FREQ; 75 76 dev_pm_opp_put(opp); 77 } 78 79 freq_table[i].driver_data = i; 80 freq_table[i].frequency = CPUFREQ_TABLE_END; 81 82 *table = &freq_table[0]; 83 84 out: 85 if (ret) 86 kfree(freq_table); 87 88 return ret; 89 } 90 EXPORT_SYMBOL_GPL(dev_pm_opp_init_cpufreq_table); 91 92 /** 93 * dev_pm_opp_free_cpufreq_table() - free the cpufreq table 94 * @dev: device for which we do this operation 95 * @table: table to free 96 * 97 * Free up the table allocated by dev_pm_opp_init_cpufreq_table 98 */ 99 void dev_pm_opp_free_cpufreq_table(struct device *dev, 100 struct cpufreq_frequency_table **table) 101 { 102 if (!table) 103 return; 104 105 kfree(*table); 106 *table = NULL; 107 } 108 EXPORT_SYMBOL_GPL(dev_pm_opp_free_cpufreq_table); 109 #endif /* CONFIG_CPU_FREQ */ 110 111 void _dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask, bool of) 112 { 113 struct device *cpu_dev; 114 int cpu; 115 116 WARN_ON(cpumask_empty(cpumask)); 117 118 for_each_cpu(cpu, cpumask) { 119 cpu_dev = get_cpu_device(cpu); 120 if (!cpu_dev) { 121 pr_err("%s: failed to get cpu%d device\n", __func__, 122 cpu); 123 continue; 124 } 125 126 if (of) 127 dev_pm_opp_of_remove_table(cpu_dev); 128 else 129 dev_pm_opp_remove_table(cpu_dev); 130 } 131 } 132 133 /** 134 * dev_pm_opp_cpumask_remove_table() - Removes OPP table for @cpumask 135 * @cpumask: cpumask for which OPP table needs to be removed 136 * 137 * This removes the OPP tables for CPUs present in the @cpumask. 138 * This should be used to remove all the OPPs entries associated with 139 * the cpus in @cpumask. 140 */ 141 void dev_pm_opp_cpumask_remove_table(const struct cpumask *cpumask) 142 { 143 _dev_pm_opp_cpumask_remove_table(cpumask, false); 144 } 145 EXPORT_SYMBOL_GPL(dev_pm_opp_cpumask_remove_table); 146 147 /** 148 * dev_pm_opp_set_sharing_cpus() - Mark OPP table as shared by few CPUs 149 * @cpu_dev: CPU device for which we do this operation 150 * @cpumask: cpumask of the CPUs which share the OPP table with @cpu_dev 151 * 152 * This marks OPP table of the @cpu_dev as shared by the CPUs present in 153 * @cpumask. 154 * 155 * Returns -ENODEV if OPP table isn't already present. 156 */ 157 int dev_pm_opp_set_sharing_cpus(struct device *cpu_dev, 158 const struct cpumask *cpumask) 159 { 160 struct opp_device *opp_dev; 161 struct opp_table *opp_table; 162 struct device *dev; 163 int cpu, ret = 0; 164 165 opp_table = _find_opp_table(cpu_dev); 166 if (IS_ERR(opp_table)) 167 return PTR_ERR(opp_table); 168 169 for_each_cpu(cpu, cpumask) { 170 if (cpu == cpu_dev->id) 171 continue; 172 173 dev = get_cpu_device(cpu); 174 if (!dev) { 175 dev_err(cpu_dev, "%s: failed to get cpu%d device\n", 176 __func__, cpu); 177 continue; 178 } 179 180 opp_dev = _add_opp_dev(dev, opp_table); 181 if (!opp_dev) { 182 dev_err(dev, "%s: failed to add opp-dev for cpu%d device\n", 183 __func__, cpu); 184 continue; 185 } 186 187 /* Mark opp-table as multiple CPUs are sharing it now */ 188 opp_table->shared_opp = OPP_TABLE_ACCESS_SHARED; 189 } 190 191 dev_pm_opp_put_opp_table(opp_table); 192 193 return ret; 194 } 195 EXPORT_SYMBOL_GPL(dev_pm_opp_set_sharing_cpus); 196 197 /** 198 * dev_pm_opp_get_sharing_cpus() - Get cpumask of CPUs sharing OPPs with @cpu_dev 199 * @cpu_dev: CPU device for which we do this operation 200 * @cpumask: cpumask to update with information of sharing CPUs 201 * 202 * This updates the @cpumask with CPUs that are sharing OPPs with @cpu_dev. 203 * 204 * Returns -ENODEV if OPP table isn't already present and -EINVAL if the OPP 205 * table's status is access-unknown. 206 */ 207 int dev_pm_opp_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask) 208 { 209 struct opp_device *opp_dev; 210 struct opp_table *opp_table; 211 int ret = 0; 212 213 opp_table = _find_opp_table(cpu_dev); 214 if (IS_ERR(opp_table)) 215 return PTR_ERR(opp_table); 216 217 if (opp_table->shared_opp == OPP_TABLE_ACCESS_UNKNOWN) { 218 ret = -EINVAL; 219 goto put_opp_table; 220 } 221 222 cpumask_clear(cpumask); 223 224 if (opp_table->shared_opp == OPP_TABLE_ACCESS_SHARED) { 225 list_for_each_entry(opp_dev, &opp_table->dev_list, node) 226 cpumask_set_cpu(opp_dev->dev->id, cpumask); 227 } else { 228 cpumask_set_cpu(cpu_dev->id, cpumask); 229 } 230 231 put_opp_table: 232 dev_pm_opp_put_opp_table(opp_table); 233 234 return ret; 235 } 236 EXPORT_SYMBOL_GPL(dev_pm_opp_get_sharing_cpus); 237