Blame view
drivers/cpufreq/sun50i-cpufreq-nvmem.c
4.96 KB
f328584f7
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 |
// SPDX-License-Identifier: GPL-2.0 /* * Allwinner CPUFreq nvmem based driver * * The sun50i-cpufreq-nvmem driver reads the efuse value from the SoC to * provide the OPP framework with required information. * * Copyright (C) 2019 Yangtao Li <tiny.windzz@gmail.com> */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/module.h> #include <linux/nvmem-consumer.h> #include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/pm_opp.h> #include <linux/slab.h> #define MAX_NAME_LEN 7 #define NVMEM_MASK 0x7 #define NVMEM_SHIFT 5 static struct platform_device *cpufreq_dt_pdev, *sun50i_cpufreq_pdev; /** |
bf76b8a26
|
28 |
* sun50i_cpufreq_get_efuse() - Determine speed grade from efuse value |
f328584f7
|
29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 |
* @versions: Set to the value parsed from efuse * * Returns 0 if success. */ static int sun50i_cpufreq_get_efuse(u32 *versions) { struct nvmem_cell *speedbin_nvmem; struct device_node *np; struct device *cpu_dev; u32 *speedbin, efuse_value; size_t len; int ret; cpu_dev = get_cpu_device(0); if (!cpu_dev) return -ENODEV; np = dev_pm_opp_of_get_opp_desc_node(cpu_dev); if (!np) return -ENOENT; ret = of_device_is_compatible(np, "allwinner,sun50i-h6-operating-points"); if (!ret) { of_node_put(np); return -ENOENT; } speedbin_nvmem = of_nvmem_cell_get(np, NULL); of_node_put(np); if (IS_ERR(speedbin_nvmem)) { if (PTR_ERR(speedbin_nvmem) != -EPROBE_DEFER) pr_err("Could not get nvmem cell: %ld ", PTR_ERR(speedbin_nvmem)); return PTR_ERR(speedbin_nvmem); } speedbin = nvmem_cell_read(speedbin_nvmem, &len); nvmem_cell_put(speedbin_nvmem); if (IS_ERR(speedbin)) return PTR_ERR(speedbin); efuse_value = (*speedbin >> NVMEM_SHIFT) & NVMEM_MASK; |
bf76b8a26
|
73 74 75 76 77 78 79 80 81 |
/* * We treat unexpected efuse values as if the SoC was from * the slowest bin. Expected efuse values are 1-3, slowest * to fastest. */ if (efuse_value >= 1 && efuse_value <= 3) *versions = efuse_value - 1; else |
f328584f7
|
82 |
*versions = 0; |
f328584f7
|
83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 |
kfree(speedbin); return 0; }; static int sun50i_cpufreq_nvmem_probe(struct platform_device *pdev) { struct opp_table **opp_tables; char name[MAX_NAME_LEN]; unsigned int cpu; u32 speed = 0; int ret; opp_tables = kcalloc(num_possible_cpus(), sizeof(*opp_tables), GFP_KERNEL); if (!opp_tables) return -ENOMEM; ret = sun50i_cpufreq_get_efuse(&speed); if (ret) return ret; snprintf(name, MAX_NAME_LEN, "speed%d", speed); for_each_possible_cpu(cpu) { struct device *cpu_dev = get_cpu_device(cpu); if (!cpu_dev) { ret = -ENODEV; goto free_opp; } opp_tables[cpu] = dev_pm_opp_set_prop_name(cpu_dev, name); if (IS_ERR(opp_tables[cpu])) { ret = PTR_ERR(opp_tables[cpu]); pr_err("Failed to set prop name "); goto free_opp; } } cpufreq_dt_pdev = platform_device_register_simple("cpufreq-dt", -1, NULL, 0); if (!IS_ERR(cpufreq_dt_pdev)) { platform_set_drvdata(pdev, opp_tables); return 0; } ret = PTR_ERR(cpufreq_dt_pdev); pr_err("Failed to register platform device "); free_opp: for_each_possible_cpu(cpu) { if (IS_ERR_OR_NULL(opp_tables[cpu])) break; dev_pm_opp_put_prop_name(opp_tables[cpu]); } kfree(opp_tables); return ret; } static int sun50i_cpufreq_nvmem_remove(struct platform_device *pdev) { struct opp_table **opp_tables = platform_get_drvdata(pdev); unsigned int cpu; platform_device_unregister(cpufreq_dt_pdev); for_each_possible_cpu(cpu) dev_pm_opp_put_prop_name(opp_tables[cpu]); kfree(opp_tables); return 0; } static struct platform_driver sun50i_cpufreq_driver = { .probe = sun50i_cpufreq_nvmem_probe, .remove = sun50i_cpufreq_nvmem_remove, .driver = { .name = "sun50i-cpufreq-nvmem", }, }; static const struct of_device_id sun50i_cpufreq_match_list[] = { { .compatible = "allwinner,sun50i-h6" }, {} }; static const struct of_device_id *sun50i_cpufreq_match_node(void) { const struct of_device_id *match; struct device_node *np; np = of_find_node_by_path("/"); match = of_match_node(sun50i_cpufreq_match_list, np); of_node_put(np); return match; } /* * Since the driver depends on nvmem drivers, which may return EPROBE_DEFER, * all the real activity is done in the probe, which may be defered as well. * The init here is only registering the driver and the platform device. */ static int __init sun50i_cpufreq_init(void) { const struct of_device_id *match; int ret; match = sun50i_cpufreq_match_node(); if (!match) return -ENODEV; ret = platform_driver_register(&sun50i_cpufreq_driver); if (unlikely(ret < 0)) return ret; sun50i_cpufreq_pdev = platform_device_register_simple("sun50i-cpufreq-nvmem", -1, NULL, 0); ret = PTR_ERR_OR_ZERO(sun50i_cpufreq_pdev); if (ret == 0) return 0; platform_driver_unregister(&sun50i_cpufreq_driver); return ret; } module_init(sun50i_cpufreq_init); static void __exit sun50i_cpufreq_exit(void) { platform_device_unregister(sun50i_cpufreq_pdev); platform_driver_unregister(&sun50i_cpufreq_driver); } module_exit(sun50i_cpufreq_exit); MODULE_DESCRIPTION("Sun50i-h6 cpufreq driver"); MODULE_LICENSE("GPL v2"); |