drivers/opp/ti-opp-supply.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2016-2017 Texas Instruments Incorporated - https://www.ti.com/
   4  *      Nishanth Menon <nm@ti.com>
   5  *      Dave Gerlach <d-gerlach@ti.com>
   6  *
   7  * TI OPP supply driver that provides override into the regulator control
   8  * for generic opp core to handle devices with ABB regulator and/or
   9  * SmartReflex Class0.
  10  */
  11 #include <linux/clk.h>
  12 #include <linux/cpufreq.h>
  13 #include <linux/device.h>
  14 #include <linux/io.h>
  15 #include <linux/module.h>
  16 #include <linux/notifier.h>
  17 #include <linux/of_device.h>
  18 #include <linux/of.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/pm_opp.h>
  21 #include <linux/regulator/consumer.h>
  22 #include <linux/slab.h>
  23
  24 /**
  25  * struct ti_opp_supply_optimum_voltage_table - optimized voltage table
  26  * @reference_uv:       reference voltage (usually Nominal voltage)
  27  * @optimized_uv:       Optimized voltage from efuse
  28  */
  29 struct ti_opp_supply_optimum_voltage_table {
  30         unsigned int reference_uv;
  31         unsigned int optimized_uv;
  32 };
  33
  34 /**
  35  * struct ti_opp_supply_data - OMAP specific opp supply data
  36  * @vdd_table:  Optimized voltage mapping table
  37  * @num_vdd_table: number of entries in vdd_table
  38  * @vdd_absolute_max_voltage_uv: absolute maximum voltage in UV for the supply
  39  * @old_supplies: Placeholder for supplies information for old OPP.
  40  * @new_supplies: Placeholder for supplies information for new OPP.
  41  */
  42 struct ti_opp_supply_data {
  43         struct ti_opp_supply_optimum_voltage_table *vdd_table;
  44         u32 num_vdd_table;
  45         u32 vdd_absolute_max_voltage_uv;
  46         struct dev_pm_opp_supply old_supplies[2];
  47         struct dev_pm_opp_supply new_supplies[2];
  48 };
  49
  50 static struct ti_opp_supply_data opp_data;
  51
  52 /**
  53  * struct ti_opp_supply_of_data - device tree match data
  54  * @flags:      specific type of opp supply
  55  * @efuse_voltage_mask: mask required for efuse register representing voltage
  56  * @efuse_voltage_uv: Are the efuse entries in micro-volts? if not, assume
  57  *              milli-volts.
  58  */
  59 struct ti_opp_supply_of_data {
  60 #define OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE    BIT(1)
  61 #define OPPDM_HAS_NO_ABB                        BIT(2)
  62         const u8 flags;
  63         const u32 efuse_voltage_mask;
  64         const bool efuse_voltage_uv;
  65 };
  66
  67 /**
  68  * _store_optimized_voltages() - store optimized voltages
  69  * @dev:        ti opp supply device for which we need to store info
  70  * @data:       data specific to the device
  71  *
  72  * Picks up efuse based optimized voltages for VDD unique per device and
  73  * stores it in internal data structure for use during transition requests.
  74  *
  75  * Return: If successful, 0, else appropriate error value.
  76  */
  77 static int _store_optimized_voltages(struct device *dev,
  78                                      struct ti_opp_supply_data *data)
  79 {
  80         void __iomem *base;
  81         struct property *prop;
  82         struct resource *res;
  83         const __be32 *val;
  84         int proplen, i;
  85         int ret = 0;
  86         struct ti_opp_supply_optimum_voltage_table *table;
  87         const struct ti_opp_supply_of_data *of_data = dev_get_drvdata(dev);
  88
  89         /* pick up Efuse based voltages */
  90         res = platform_get_resource(to_platform_device(dev), IORESOURCE_MEM, 0);
  91         if (!res) {
  92                 dev_err(dev, "Unable to get IO resource\n");
  93                 ret = -ENODEV;
  94                 goto out_map;
  95         }
  96
  97         base = ioremap(res->start, resource_size(res));
  98         if (!base) {
  99                 dev_err(dev, "Unable to map Efuse registers\n");
 100                 ret = -ENOMEM;
 101                 goto out_map;
 102         }
 103
 104         /* Fetch efuse-settings. */
 105         prop = of_find_property(dev->of_node, "ti,efuse-settings", NULL);
 106         if (!prop) {
 107                 dev_err(dev, "No 'ti,efuse-settings' property found\n");
 108                 ret = -EINVAL;
 109                 goto out;
 110         }
 111
 112         proplen = prop->length / sizeof(int);
 113         data->num_vdd_table = proplen / 2;
 114         /* Verify for corrupted OPP entries in dt */
 115         if (data->num_vdd_table * 2 * sizeof(int) != prop->length) {
 116                 dev_err(dev, "Invalid 'ti,efuse-settings'\n");
 117                 ret = -EINVAL;
 118                 goto out;
 119         }
 120
 121         ret = of_property_read_u32(dev->of_node, "ti,absolute-max-voltage-uv",
 122                                    &data->vdd_absolute_max_voltage_uv);
 123         if (ret) {
 124                 dev_err(dev, "ti,absolute-max-voltage-uv is missing\n");
 125                 ret = -EINVAL;
 126                 goto out;
 127         }
 128
 129         table = kcalloc(data->num_vdd_table, sizeof(*data->vdd_table),
 130                         GFP_KERNEL);
 131         if (!table) {
 132                 ret = -ENOMEM;
 133                 goto out;
 134         }
 135         data->vdd_table = table;
 136
 137         val = prop->value;
 138         for (i = 0; i < data->num_vdd_table; i++, table++) {
 139                 u32 efuse_offset;
 140                 u32 tmp;
 141
 142                 table->reference_uv = be32_to_cpup(val++);
 143                 efuse_offset = be32_to_cpup(val++);
 144
 145                 tmp = readl(base + efuse_offset);
 146                 tmp &= of_data->efuse_voltage_mask;
 147                 tmp >>= __ffs(of_data->efuse_voltage_mask);
 148
 149                 table->optimized_uv = of_data->efuse_voltage_uv ? tmp :
 150                                         tmp * 1000;
 151
 152                 dev_dbg(dev, "[%d] efuse=0x%08x volt_table=%d vset=%d\n",
 153                         i, efuse_offset, table->reference_uv,
 154                         table->optimized_uv);
 155
 156                 /*
 157                  * Some older samples might not have optimized efuse
 158                  * Use reference voltage for those - just add debug message
 159                  * for them.
 160                  */
 161                 if (!table->optimized_uv) {
 162                         dev_dbg(dev, "[%d] efuse=0x%08x volt_table=%d:vset0\n",
 163                                 i, efuse_offset, table->reference_uv);
 164                         table->optimized_uv = table->reference_uv;
 165                 }
 166         }
 167 out:
 168         iounmap(base);
 169 out_map:
 170         return ret;
 171 }
 172
 173 /**
 174  * _free_optimized_voltages() - free resources for optvoltages
 175  * @dev:        device for which we need to free info
 176  * @data:       data specific to the device
 177  */
 178 static void _free_optimized_voltages(struct device *dev,
 179                                      struct ti_opp_supply_data *data)
 180 {
 181         kfree(data->vdd_table);
 182         data->vdd_table = NULL;
 183         data->num_vdd_table = 0;
 184 }
 185
 186 /**
 187  * _get_optimal_vdd_voltage() - Finds optimal voltage for the supply
 188  * @dev:        device for which we need to find info
 189  * @data:       data specific to the device
 190  * @reference_uv:       reference voltage (OPP voltage) for which we need value
 191  *
 192  * Return: if a match is found, return optimized voltage, else return
 193  * reference_uv, also return reference_uv if no optimization is needed.
 194  */
 195 static int _get_optimal_vdd_voltage(struct device *dev,
 196                                     struct ti_opp_supply_data *data,
 197                                     int reference_uv)
 198 {
 199         int i;
 200         struct ti_opp_supply_optimum_voltage_table *table;
 201
 202         if (!data->num_vdd_table)
 203                 return reference_uv;
 204
 205         table = data->vdd_table;
 206         if (!table)
 207                 return -EINVAL;
 208
 209         /* Find a exact match - this list is usually very small */
 210         for (i = 0; i < data->num_vdd_table; i++, table++)
 211                 if (table->reference_uv == reference_uv)
 212                         return table->optimized_uv;
 213
 214         /* IF things are screwed up, we'd make a mess on console.. ratelimit */
 215         dev_err_ratelimited(dev, "%s: Failed optimized voltage match for %d\n",
 216                             __func__, reference_uv);
 217         return reference_uv;
 218 }
 219
 220 static int _opp_set_voltage(struct device *dev,
 221                             struct dev_pm_opp_supply *supply,
 222                             int new_target_uv, struct regulator *reg,
 223                             char *reg_name)
 224 {
 225         int ret;
 226         unsigned long vdd_uv, uv_max;
 227
 228         if (new_target_uv)
 229                 vdd_uv = new_target_uv;
 230         else
 231                 vdd_uv = supply->u_volt;
 232
 233         /*
 234          * If we do have an absolute max voltage specified, then we should
 235          * use that voltage instead to allow for cases where the voltage rails
 236          * are ganged (example if we set the max for an opp as 1.12v, and
 237          * the absolute max is 1.5v, for another rail to get 1.25v, it cannot
 238          * be achieved if the regulator is constrainted to max of 1.12v, even
 239          * if it can function at 1.25v
 240          */
 241         if (opp_data.vdd_absolute_max_voltage_uv)
 242                 uv_max = opp_data.vdd_absolute_max_voltage_uv;
 243         else
 244                 uv_max = supply->u_volt_max;
 245
 246         if (vdd_uv > uv_max ||
 247             vdd_uv < supply->u_volt_min ||
 248             supply->u_volt_min > uv_max) {
 249                 dev_warn(dev,
 250                          "Invalid range voltages [Min:%lu target:%lu Max:%lu]\n",
 251                          supply->u_volt_min, vdd_uv, uv_max);
 252                 return -EINVAL;
 253         }
 254
 255         dev_dbg(dev, "%s scaling to %luuV[min %luuV max %luuV]\n", reg_name,
 256                 vdd_uv, supply->u_volt_min,
 257                 uv_max);
 258
 259         ret = regulator_set_voltage_triplet(reg,
 260                                             supply->u_volt_min,
 261                                             vdd_uv,
 262                                             uv_max);
 263         if (ret) {
 264                 dev_err(dev, "%s failed for %luuV[min %luuV max %luuV]\n",
 265                         reg_name, vdd_uv, supply->u_volt_min,
 266                         uv_max);
 267                 return ret;
 268         }
 269
 270         return 0;
 271 }
 272
 273 /* Do the opp supply transition */
 274 static int ti_opp_config_regulators(struct device *dev,
 275                         struct dev_pm_opp *old_opp, struct dev_pm_opp *new_opp,
 276                         struct regulator **regulators, unsigned int count)
 277 {
 278         struct dev_pm_opp_supply *old_supply_vdd = &opp_data.old_supplies[0];
 279         struct dev_pm_opp_supply *old_supply_vbb = &opp_data.old_supplies[1];
 280         struct dev_pm_opp_supply *new_supply_vdd = &opp_data.new_supplies[0];
 281         struct dev_pm_opp_supply *new_supply_vbb = &opp_data.new_supplies[1];
 282         struct regulator *vdd_reg = regulators[0];
 283         struct regulator *vbb_reg = regulators[1];
 284         unsigned long old_freq, freq;
 285         int vdd_uv;
 286         int ret;
 287
 288         /* We must have two regulators here */
 289         WARN_ON(count != 2);
 290
 291         /* Fetch supplies and freq information from OPP core */
 292         ret = dev_pm_opp_get_supplies(new_opp, opp_data.new_supplies);
 293         WARN_ON(ret);
 294
 295         old_freq = dev_pm_opp_get_freq(old_opp);
 296         freq = dev_pm_opp_get_freq(new_opp);
 297         WARN_ON(!old_freq || !freq);
 298
 299         vdd_uv = _get_optimal_vdd_voltage(dev, &opp_data,
 300                                           new_supply_vdd->u_volt);
 301
 302         if (new_supply_vdd->u_volt_min < vdd_uv)
 303                 new_supply_vdd->u_volt_min = vdd_uv;
 304
 305         /* Scaling up? Scale voltage before frequency */
 306         if (freq > old_freq) {
 307                 ret = _opp_set_voltage(dev, new_supply_vdd, vdd_uv, vdd_reg,
 308                                        "vdd");
 309                 if (ret)
 310                         goto restore_voltage;
 311
 312                 ret = _opp_set_voltage(dev, new_supply_vbb, 0, vbb_reg, "vbb");
 313                 if (ret)
 314                         goto restore_voltage;
 315         } else {
 316                 ret = _opp_set_voltage(dev, new_supply_vbb, 0, vbb_reg, "vbb");
 317                 if (ret)
 318                         goto restore_voltage;
 319
 320                 ret = _opp_set_voltage(dev, new_supply_vdd, vdd_uv, vdd_reg,
 321                                        "vdd");
 322                 if (ret)
 323                         goto restore_voltage;
 324         }
 325
 326         return 0;
 327
 328 restore_voltage:
 329         /* Fetch old supplies information only if required */
 330         ret = dev_pm_opp_get_supplies(old_opp, opp_data.old_supplies);
 331         WARN_ON(ret);
 332
 333         /* This shouldn't harm even if the voltages weren't updated earlier */
 334         if (old_supply_vdd->u_volt) {
 335                 ret = _opp_set_voltage(dev, old_supply_vbb, 0, vbb_reg, "vbb");
 336                 if (ret)
 337                         return ret;
 338
 339                 ret = _opp_set_voltage(dev, old_supply_vdd, 0, vdd_reg,
 340                                        "vdd");
 341                 if (ret)
 342                         return ret;
 343         }
 344
 345         return ret;
 346 }
 347
 348 static const struct ti_opp_supply_of_data omap_generic_of_data = {
 349 };
 350
 351 static const struct ti_opp_supply_of_data omap_omap5_of_data = {
 352         .flags = OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE,
 353         .efuse_voltage_mask = 0xFFF,
 354         .efuse_voltage_uv = false,
 355 };
 356
 357 static const struct ti_opp_supply_of_data omap_omap5core_of_data = {
 358         .flags = OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE | OPPDM_HAS_NO_ABB,
 359         .efuse_voltage_mask = 0xFFF,
 360         .efuse_voltage_uv = false,
 361 };
 362
 363 static const struct of_device_id ti_opp_supply_of_match[] = {
 364         {.compatible = "ti,omap-opp-supply", .data = &omap_generic_of_data},
 365         {.compatible = "ti,omap5-opp-supply", .data = &omap_omap5_of_data},
 366         {.compatible = "ti,omap5-core-opp-supply",
 367          .data = &omap_omap5core_of_data},
 368         {},
 369 };
 370 MODULE_DEVICE_TABLE(of, ti_opp_supply_of_match);
 371
 372 static int ti_opp_supply_probe(struct platform_device *pdev)
 373 {
 374         struct device *dev = &pdev->dev;
 375         struct device *cpu_dev = get_cpu_device(0);
 376         const struct of_device_id *match;
 377         const struct ti_opp_supply_of_data *of_data;
 378         int ret = 0;
 379
 380         match = of_match_device(ti_opp_supply_of_match, dev);
 381         if (!match) {
 382                 /* We do not expect this to happen */
 383                 dev_err(dev, "%s: Unable to match device\n", __func__);
 384                 return -ENODEV;
 385         }
 386         if (!match->data) {
 387                 /* Again, unlikely.. but mistakes do happen */
 388                 dev_err(dev, "%s: Bad data in match\n", __func__);
 389                 return -EINVAL;
 390         }
 391         of_data = match->data;
 392
 393         dev_set_drvdata(dev, (void *)of_data);
 394
 395         /* If we need optimized voltage */
 396         if (of_data->flags & OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE) {
 397                 ret = _store_optimized_voltages(dev, &opp_data);
 398                 if (ret)
 399                         return ret;
 400         }
 401
 402         ret = dev_pm_opp_set_config_regulators(cpu_dev, ti_opp_config_regulators);
 403         if (ret < 0)
 404                 _free_optimized_voltages(dev, &opp_data);
 405
 406         return ret;
 407 }
 408
 409 static struct platform_driver ti_opp_supply_driver = {
 410         .probe = ti_opp_supply_probe,
 411         .driver = {
 412                    .name = "ti_opp_supply",
 413                    .of_match_table = of_match_ptr(ti_opp_supply_of_match),
 414                    },
 415 };
 416 module_platform_driver(ti_opp_supply_driver);
 417
 418 MODULE_DESCRIPTION("Texas Instruments OMAP OPP Supply driver");
 419 MODULE_AUTHOR("Texas Instruments Inc.");
 420 MODULE_LICENSE("GPL v2");