drivers/cpufreq/ti-cpufreq.c

   1 /*
   2  * TI CPUFreq/OPP hw-supported driver
   3  *
   4  * Copyright (C) 2016-2017 Texas Instruments, Inc.
   5  *       Dave Gerlach <d-gerlach@ti.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * version 2 as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include <linux/cpu.h>
  18 #include <linux/io.h>
  19 #include <linux/mfd/syscon.h>
  20 #include <linux/module.h>
  21 #include <linux/init.h>
  22 #include <linux/of.h>
  23 #include <linux/of_platform.h>
  24 #include <linux/pm_opp.h>
  25 #include <linux/regmap.h>
  26 #include <linux/slab.h>
  27
  28 #define REVISION_MASK                           0xF
  29 #define REVISION_SHIFT                          28
  30
  31 #define AM33XX_800M_ARM_MPU_MAX_FREQ            0x1E2F
  32 #define AM43XX_600M_ARM_MPU_MAX_FREQ            0xFFA
  33
  34 #define DRA7_EFUSE_HAS_OD_MPU_OPP               11
  35 #define DRA7_EFUSE_HAS_HIGH_MPU_OPP             15
  36 #define DRA7_EFUSE_HAS_ALL_MPU_OPP              23
  37
  38 #define DRA7_EFUSE_NOM_MPU_OPP                  BIT(0)
  39 #define DRA7_EFUSE_OD_MPU_OPP                   BIT(1)
  40 #define DRA7_EFUSE_HIGH_MPU_OPP                 BIT(2)
  41
  42 #define VERSION_COUNT                           2
  43
  44 struct ti_cpufreq_data;
  45
  46 struct ti_cpufreq_soc_data {
  47         unsigned long (*efuse_xlate)(struct ti_cpufreq_data *opp_data,
  48                                      unsigned long efuse);
  49         unsigned long efuse_fallback;
  50         unsigned long efuse_offset;
  51         unsigned long efuse_mask;
  52         unsigned long efuse_shift;
  53         unsigned long rev_offset;
  54         bool multi_regulator;
  55 };
  56
  57 struct ti_cpufreq_data {
  58         struct device *cpu_dev;
  59         struct device_node *opp_node;
  60         struct regmap *syscon;
  61         const struct ti_cpufreq_soc_data *soc_data;
  62         struct opp_table *opp_table;
  63 };
  64
  65 static unsigned long amx3_efuse_xlate(struct ti_cpufreq_data *opp_data,
  66                                       unsigned long efuse)
  67 {
  68         if (!efuse)
  69                 efuse = opp_data->soc_data->efuse_fallback;
  70         /* AM335x and AM437x use "OPP disable" bits, so invert */
  71         return ~efuse;
  72 }
  73
  74 static unsigned long dra7_efuse_xlate(struct ti_cpufreq_data *opp_data,
  75                                       unsigned long efuse)
  76 {
  77         unsigned long calculated_efuse = DRA7_EFUSE_NOM_MPU_OPP;
  78
  79         /*
  80          * The efuse on dra7 and am57 parts contains a specific
  81          * value indicating the highest available OPP.
  82          */
  83
  84         switch (efuse) {
  85         case DRA7_EFUSE_HAS_ALL_MPU_OPP:
  86         case DRA7_EFUSE_HAS_HIGH_MPU_OPP:
  87                 calculated_efuse |= DRA7_EFUSE_HIGH_MPU_OPP;
  88         case DRA7_EFUSE_HAS_OD_MPU_OPP:
  89                 calculated_efuse |= DRA7_EFUSE_OD_MPU_OPP;
  90         }
  91
  92         return calculated_efuse;
  93 }
  94
  95 static struct ti_cpufreq_soc_data am3x_soc_data = {
  96         .efuse_xlate = amx3_efuse_xlate,
  97         .efuse_fallback = AM33XX_800M_ARM_MPU_MAX_FREQ,
  98         .efuse_offset = 0x07fc,
  99         .efuse_mask = 0x1fff,
 100         .rev_offset = 0x600,
 101         .multi_regulator = false,
 102 };
 103
 104 static struct ti_cpufreq_soc_data am4x_soc_data = {
 105         .efuse_xlate = amx3_efuse_xlate,
 106         .efuse_fallback = AM43XX_600M_ARM_MPU_MAX_FREQ,
 107         .efuse_offset = 0x0610,
 108         .efuse_mask = 0x3f,
 109         .rev_offset = 0x600,
 110         .multi_regulator = false,
 111 };
 112
 113 static struct ti_cpufreq_soc_data dra7_soc_data = {
 114         .efuse_xlate = dra7_efuse_xlate,
 115         .efuse_offset = 0x020c,
 116         .efuse_mask = 0xf80000,
 117         .efuse_shift = 19,
 118         .rev_offset = 0x204,
 119         .multi_regulator = true,
 120 };
 121
 122 /**
 123  * ti_cpufreq_get_efuse() - Parse and return efuse value present on SoC
 124  * @opp_data: pointer to ti_cpufreq_data context
 125  * @efuse_value: Set to the value parsed from efuse
 126  *
 127  * Returns error code if efuse not read properly.
 128  */
 129 static int ti_cpufreq_get_efuse(struct ti_cpufreq_data *opp_data,
 130                                 u32 *efuse_value)
 131 {
 132         struct device *dev = opp_data->cpu_dev;
 133         u32 efuse;
 134         int ret;
 135
 136         ret = regmap_read(opp_data->syscon, opp_data->soc_data->efuse_offset,
 137                           &efuse);
 138         if (ret) {
 139                 dev_err(dev,
 140                         "Failed to read the efuse value from syscon: %d\n",
 141                         ret);
 142                 return ret;
 143         }
 144
 145         efuse = (efuse & opp_data->soc_data->efuse_mask);
 146         efuse >>= opp_data->soc_data->efuse_shift;
 147
 148         *efuse_value = opp_data->soc_data->efuse_xlate(opp_data, efuse);
 149
 150         return 0;
 151 }
 152
 153 /**
 154  * ti_cpufreq_get_rev() - Parse and return rev value present on SoC
 155  * @opp_data: pointer to ti_cpufreq_data context
 156  * @revision_value: Set to the value parsed from revision register
 157  *
 158  * Returns error code if revision not read properly.
 159  */
 160 static int ti_cpufreq_get_rev(struct ti_cpufreq_data *opp_data,
 161                               u32 *revision_value)
 162 {
 163         struct device *dev = opp_data->cpu_dev;
 164         u32 revision;
 165         int ret;
 166
 167         ret = regmap_read(opp_data->syscon, opp_data->soc_data->rev_offset,
 168                           &revision);
 169         if (ret) {
 170                 dev_err(dev,
 171                         "Failed to read the revision number from syscon: %d\n",
 172                         ret);
 173                 return ret;
 174         }
 175
 176         *revision_value = BIT((revision >> REVISION_SHIFT) & REVISION_MASK);
 177
 178         return 0;
 179 }
 180
 181 static int ti_cpufreq_setup_syscon_register(struct ti_cpufreq_data *opp_data)
 182 {
 183         struct device *dev = opp_data->cpu_dev;
 184         struct device_node *np = opp_data->opp_node;
 185
 186         opp_data->syscon = syscon_regmap_lookup_by_phandle(np,
 187                                                         "syscon");
 188         if (IS_ERR(opp_data->syscon)) {
 189                 dev_err(dev,
 190                         "\"syscon\" is missing, cannot use OPPv2 table.\n");
 191                 return PTR_ERR(opp_data->syscon);
 192         }
 193
 194         return 0;
 195 }
 196
 197 static const struct of_device_id ti_cpufreq_of_match[] = {
 198         { .compatible = "ti,am33xx", .data = &am3x_soc_data, },
 199         { .compatible = "ti,am43", .data = &am4x_soc_data, },
 200         { .compatible = "ti,dra7", .data = &dra7_soc_data },
 201         {},
 202 };
 203
 204 static int ti_cpufreq_probe(struct platform_device *pdev)
 205 {
 206         u32 version[VERSION_COUNT];
 207         struct device_node *np;
 208         const struct of_device_id *match;
 209         struct opp_table *ti_opp_table;
 210         struct ti_cpufreq_data *opp_data;
 211         const char * const reg_names[] = {"vdd", "vbb"};
 212         int ret;
 213
 214         np = of_find_node_by_path("/");
 215         match = of_match_node(ti_cpufreq_of_match, np);
 216         of_node_put(np);
 217         if (!match)
 218                 return -ENODEV;
 219
 220         opp_data = kzalloc(sizeof(*opp_data), GFP_KERNEL);
 221         if (!opp_data)
 222                 return -ENOMEM;
 223
 224         opp_data->soc_data = match->data;
 225
 226         opp_data->cpu_dev = get_cpu_device(0);
 227         if (!opp_data->cpu_dev) {
 228                 pr_err("%s: Failed to get device for CPU0\n", __func__);
 229                 ret = ENODEV;
 230                 goto free_opp_data;
 231         }
 232
 233         opp_data->opp_node = dev_pm_opp_of_get_opp_desc_node(opp_data->cpu_dev);
 234         if (!opp_data->opp_node) {
 235                 dev_info(opp_data->cpu_dev,
 236                          "OPP-v2 not supported, cpufreq-dt will attempt to use legacy tables.\n");
 237                 goto register_cpufreq_dt;
 238         }
 239
 240         ret = ti_cpufreq_setup_syscon_register(opp_data);
 241         if (ret)
 242                 goto fail_put_node;
 243
 244         /*
 245          * OPPs determine whether or not they are supported based on
 246          * two metrics:
 247          *      0 - SoC Revision
 248          *      1 - eFuse value
 249          */
 250         ret = ti_cpufreq_get_rev(opp_data, &version[0]);
 251         if (ret)
 252                 goto fail_put_node;
 253
 254         ret = ti_cpufreq_get_efuse(opp_data, &version[1]);
 255         if (ret)
 256                 goto fail_put_node;
 257
 258         ti_opp_table = dev_pm_opp_set_supported_hw(opp_data->cpu_dev,
 259                                                    version, VERSION_COUNT);
 260         if (IS_ERR(ti_opp_table)) {
 261                 dev_err(opp_data->cpu_dev,
 262                         "Failed to set supported hardware\n");
 263                 ret = PTR_ERR(ti_opp_table);
 264                 goto fail_put_node;
 265         }
 266
 267         opp_data->opp_table = ti_opp_table;
 268
 269         if (opp_data->soc_data->multi_regulator) {
 270                 ti_opp_table = dev_pm_opp_set_regulators(opp_data->cpu_dev,
 271                                                          reg_names,
 272                                                          ARRAY_SIZE(reg_names));
 273                 if (IS_ERR(ti_opp_table)) {
 274                         dev_pm_opp_put_supported_hw(opp_data->opp_table);
 275                         ret =  PTR_ERR(ti_opp_table);
 276                         goto fail_put_node;
 277                 }
 278         }
 279
 280         of_node_put(opp_data->opp_node);
 281 register_cpufreq_dt:
 282         platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
 283
 284         return 0;
 285
 286 fail_put_node:
 287         of_node_put(opp_data->opp_node);
 288 free_opp_data:
 289         kfree(opp_data);
 290
 291         return ret;
 292 }
 293
 294 static int ti_cpufreq_init(void)
 295 {
 296         platform_device_register_simple("ti-cpufreq", -1, NULL, 0);
 297         return 0;
 298 }
 299 module_init(ti_cpufreq_init);
 300
 301 static struct platform_driver ti_cpufreq_driver = {
 302         .probe = ti_cpufreq_probe,
 303         .driver = {
 304                 .name = "ti-cpufreq",
 305         },
 306 };
 307 module_platform_driver(ti_cpufreq_driver);
 308
 309 MODULE_DESCRIPTION("TI CPUFreq/OPP hw-supported driver");
 310 MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>");
 311 MODULE_LICENSE("GPL v2");