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