drivers/opp/ti-opp-supply.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2016-2017 Texas Instruments Incorporated - http://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  */
  40 struct ti_opp_supply_data {
  41         struct ti_opp_supply_optimum_voltage_table *vdd_table;
  42         u32 num_vdd_table;
  43         u32 vdd_absolute_max_voltage_uv;
  44 };
  45
  46 static struct ti_opp_supply_data opp_data;
  47
  48 /**
  49  * struct ti_opp_supply_of_data - device tree match data
  50  * @flags:      specific type of opp supply
  51  * @efuse_voltage_mask: mask required for efuse register representing voltage
  52  * @efuse_voltage_uv: Are the efuse entries in micro-volts? if not, assume
  53  *              milli-volts.
  54  */
  55 struct ti_opp_supply_of_data {
  56 #define OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE    BIT(1)
  57 #define OPPDM_HAS_NO_ABB                        BIT(2)
  58         const u8 flags;
  59         const u32 efuse_voltage_mask;
  60         const bool efuse_voltage_uv;
  61 };
  62
  63 /**
  64  * _store_optimized_voltages() - store optimized voltages
  65  * @dev:        ti opp supply device for which we need to store info
  66  * @data:       data specific to the device
  67  *
  68  * Picks up efuse based optimized voltages for VDD unique per device and
  69  * stores it in internal data structure for use during transition requests.
  70  *
  71  * Return: If successful, 0, else appropriate error value.
  72  */
  73 static int _store_optimized_voltages(struct device *dev,
  74                                      struct ti_opp_supply_data *data)
  75 {
  76         void __iomem *base;
  77         struct property *prop;
  78         struct resource *res;
  79         const __be32 *val;
  80         int proplen, i;
  81         int ret = 0;
  82         struct ti_opp_supply_optimum_voltage_table *table;
  83         const struct ti_opp_supply_of_data *of_data = dev_get_drvdata(dev);
  84
  85         /* pick up Efuse based voltages */
  86         res = platform_get_resource(to_platform_device(dev), IORESOURCE_MEM, 0);
  87         if (!res) {
  88                 dev_err(dev, "Unable to get IO resource\n");
  89                 ret = -ENODEV;
  90                 goto out_map;
  91         }
  92
  93         base = ioremap_nocache(res->start, resource_size(res));
  94         if (!base) {
  95                 dev_err(dev, "Unable to map Efuse registers\n");
  96                 ret = -ENOMEM;
  97                 goto out_map;
  98         }
  99
 100         /* Fetch efuse-settings. */
 101         prop = of_find_property(dev->of_node, "ti,efuse-settings", NULL);
 102         if (!prop) {
 103                 dev_err(dev, "No 'ti,efuse-settings' property found\n");
 104                 ret = -EINVAL;
 105                 goto out;
 106         }
 107
 108         proplen = prop->length / sizeof(int);
 109         data->num_vdd_table = proplen / 2;
 110         /* Verify for corrupted OPP entries in dt */
 111         if (data->num_vdd_table * 2 * sizeof(int) != prop->length) {
 112                 dev_err(dev, "Invalid 'ti,efuse-settings'\n");
 113                 ret = -EINVAL;
 114                 goto out;
 115         }
 116
 117         ret = of_property_read_u32(dev->of_node, "ti,absolute-max-voltage-uv",
 118                                    &data->vdd_absolute_max_voltage_uv);
 119         if (ret) {
 120                 dev_err(dev, "ti,absolute-max-voltage-uv is missing\n");
 121                 ret = -EINVAL;
 122                 goto out;
 123         }
 124
 125         table = kcalloc(data->num_vdd_table, sizeof(*data->vdd_table),
 126                         GFP_KERNEL);
 127         if (!table) {
 128                 ret = -ENOMEM;
 129                 goto out;
 130         }
 131         data->vdd_table = table;
 132
 133         val = prop->value;
 134         for (i = 0; i < data->num_vdd_table; i++, table++) {
 135                 u32 efuse_offset;
 136                 u32 tmp;
 137
 138                 table->reference_uv = be32_to_cpup(val++);
 139                 efuse_offset = be32_to_cpup(val++);
 140
 141                 tmp = readl(base + efuse_offset);
 142                 tmp &= of_data->efuse_voltage_mask;
 143                 tmp >>= __ffs(of_data->efuse_voltage_mask);
 144
 145                 table->optimized_uv = of_data->efuse_voltage_uv ? tmp :
 146                                         tmp * 1000;
 147
 148                 dev_dbg(dev, "[%d] efuse=0x%08x volt_table=%d vset=%d\n",
 149                         i, efuse_offset, table->reference_uv,
 150                         table->optimized_uv);
 151
 152                 /*
 153                  * Some older samples might not have optimized efuse
 154                  * Use reference voltage for those - just add debug message
 155                  * for them.
 156                  */
 157                 if (!table->optimized_uv) {
 158                         dev_dbg(dev, "[%d] efuse=0x%08x volt_table=%d:vset0\n",
 159                                 i, efuse_offset, table->reference_uv);
 160                         table->optimized_uv = table->reference_uv;
 161                 }
 162         }
 163 out:
 164         iounmap(base);
 165 out_map:
 166         return ret;
 167 }
 168
 169 /**
 170  * _free_optimized_voltages() - free resources for optvoltages
 171  * @dev:        device for which we need to free info
 172  * @data:       data specific to the device
 173  */
 174 static void _free_optimized_voltages(struct device *dev,
 175                                      struct ti_opp_supply_data *data)
 176 {
 177         kfree(data->vdd_table);
 178         data->vdd_table = NULL;
 179         data->num_vdd_table = 0;
 180 }
 181
 182 /**
 183  * _get_optimal_vdd_voltage() - Finds optimal voltage for the supply
 184  * @dev:        device for which we need to find info
 185  * @data:       data specific to the device
 186  * @reference_uv:       reference voltage (OPP voltage) for which we need value
 187  *
 188  * Return: if a match is found, return optimized voltage, else return
 189  * reference_uv, also return reference_uv if no optimization is needed.
 190  */
 191 static int _get_optimal_vdd_voltage(struct device *dev,
 192                                     struct ti_opp_supply_data *data,
 193                                     int reference_uv)
 194 {
 195         int i;
 196         struct ti_opp_supply_optimum_voltage_table *table;
 197
 198         if (!data->num_vdd_table)
 199                 return reference_uv;
 200
 201         table = data->vdd_table;
 202         if (!table)
 203                 return -EINVAL;
 204
 205         /* Find a exact match - this list is usually very small */
 206         for (i = 0; i < data->num_vdd_table; i++, table++)
 207                 if (table->reference_uv == reference_uv)
 208                         return table->optimized_uv;
 209
 210         /* IF things are screwed up, we'd make a mess on console.. ratelimit */
 211         dev_err_ratelimited(dev, "%s: Failed optimized voltage match for %d\n",
 212                             __func__, reference_uv);
 213         return reference_uv;
 214 }
 215
 216 static int _opp_set_voltage(struct device *dev,
 217                             struct dev_pm_opp_supply *supply,
 218                             int new_target_uv, struct regulator *reg,
 219                             char *reg_name)
 220 {
 221         int ret;
 222         unsigned long vdd_uv, uv_max;
 223
 224         if (new_target_uv)
 225                 vdd_uv = new_target_uv;
 226         else
 227                 vdd_uv = supply->u_volt;
 228
 229         /*
 230          * If we do have an absolute max voltage specified, then we should
 231          * use that voltage instead to allow for cases where the voltage rails
 232          * are ganged (example if we set the max for an opp as 1.12v, and
 233          * the absolute max is 1.5v, for another rail to get 1.25v, it cannot
 234          * be achieved if the regulator is constrainted to max of 1.12v, even
 235          * if it can function at 1.25v
 236          */
 237         if (opp_data.vdd_absolute_max_voltage_uv)
 238                 uv_max = opp_data.vdd_absolute_max_voltage_uv;
 239         else
 240                 uv_max = supply->u_volt_max;
 241
 242         if (vdd_uv > uv_max ||
 243             vdd_uv < supply->u_volt_min ||
 244             supply->u_volt_min > uv_max) {
 245                 dev_warn(dev,
 246                          "Invalid range voltages [Min:%lu target:%lu Max:%lu]\n",
 247                          supply->u_volt_min, vdd_uv, uv_max);
 248                 return -EINVAL;
 249         }
 250
 251         dev_dbg(dev, "%s scaling to %luuV[min %luuV max %luuV]\n", reg_name,
 252                 vdd_uv, supply->u_volt_min,
 253                 uv_max);
 254
 255         ret = regulator_set_voltage_triplet(reg,
 256                                             supply->u_volt_min,
 257                                             vdd_uv,
 258                                             uv_max);
 259         if (ret) {
 260                 dev_err(dev, "%s failed for %luuV[min %luuV max %luuV]\n",
 261                         reg_name, vdd_uv, supply->u_volt_min,
 262                         uv_max);
 263                 return ret;
 264         }
 265
 266         return 0;
 267 }
 268
 269 /**
 270  * ti_opp_supply_set_opp() - do the opp supply transition
 271  * @data:       information on regulators and new and old opps provided by
 272  *              opp core to use in transition
 273  *
 274  * Return: If successful, 0, else appropriate error value.
 275  */
 276 static int ti_opp_supply_set_opp(struct dev_pm_set_opp_data *data)
 277 {
 278         struct dev_pm_opp_supply *old_supply_vdd = &data->old_opp.supplies[0];
 279         struct dev_pm_opp_supply *old_supply_vbb = &data->old_opp.supplies[1];
 280         struct dev_pm_opp_supply *new_supply_vdd = &data->new_opp.supplies[0];
 281         struct dev_pm_opp_supply *new_supply_vbb = &data->new_opp.supplies[1];
 282         struct device *dev = data->dev;
 283         unsigned long old_freq = data->old_opp.rate, freq = data->new_opp.rate;
 284         struct clk *clk = data->clk;
 285         struct regulator *vdd_reg = data->regulators[0];
 286         struct regulator *vbb_reg = data->regulators[1];
 287         int vdd_uv;
 288         int ret;
 289
 290         vdd_uv = _get_optimal_vdd_voltage(dev, &opp_data,
 291                                           new_supply_vdd->u_volt);
 292
 293         if (new_supply_vdd->u_volt_min < vdd_uv)
 294                 new_supply_vdd->u_volt_min = vdd_uv;
 295
 296         /* Scaling up? Scale voltage before frequency */
 297         if (freq > old_freq) {
 298                 ret = _opp_set_voltage(dev, new_supply_vdd, vdd_uv, vdd_reg,
 299                                        "vdd");
 300                 if (ret)
 301                         goto restore_voltage;
 302
 303                 ret = _opp_set_voltage(dev, new_supply_vbb, 0, vbb_reg, "vbb");
 304                 if (ret)
 305                         goto restore_voltage;
 306         }
 307
 308         /* Change frequency */
 309         dev_dbg(dev, "%s: switching OPP: %lu Hz --> %lu Hz\n",
 310                 __func__, old_freq, freq);
 311
 312         ret = clk_set_rate(clk, freq);
 313         if (ret) {
 314                 dev_err(dev, "%s: failed to set clock rate: %d\n", __func__,
 315                         ret);
 316                 goto restore_voltage;
 317         }
 318
 319         /* Scaling down? Scale voltage after frequency */
 320         if (freq < old_freq) {
 321                 ret = _opp_set_voltage(dev, new_supply_vbb, 0, vbb_reg, "vbb");
 322                 if (ret)
 323                         goto restore_freq;
 324
 325                 ret = _opp_set_voltage(dev, new_supply_vdd, vdd_uv, vdd_reg,
 326                                        "vdd");
 327                 if (ret)
 328                         goto restore_freq;
 329         }
 330
 331         return 0;
 332
 333 restore_freq:
 334         ret = clk_set_rate(clk, old_freq);
 335         if (ret)
 336                 dev_err(dev, "%s: failed to restore old-freq (%lu Hz)\n",
 337                         __func__, old_freq);
 338 restore_voltage:
 339         /* This shouldn't harm even if the voltages weren't updated earlier */
 340         if (old_supply_vdd->u_volt) {
 341                 ret = _opp_set_voltage(dev, old_supply_vbb, 0, vbb_reg, "vbb");
 342                 if (ret)
 343                         return ret;
 344
 345                 ret = _opp_set_voltage(dev, old_supply_vdd, 0, vdd_reg,
 346                                        "vdd");
 347                 if (ret)
 348                         return ret;
 349         }
 350
 351         return ret;
 352 }
 353
 354 static const struct ti_opp_supply_of_data omap_generic_of_data = {
 355 };
 356
 357 static const struct ti_opp_supply_of_data omap_omap5_of_data = {
 358         .flags = OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE,
 359         .efuse_voltage_mask = 0xFFF,
 360         .efuse_voltage_uv = false,
 361 };
 362
 363 static const struct ti_opp_supply_of_data omap_omap5core_of_data = {
 364         .flags = OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE | OPPDM_HAS_NO_ABB,
 365         .efuse_voltage_mask = 0xFFF,
 366         .efuse_voltage_uv = false,
 367 };
 368
 369 static const struct of_device_id ti_opp_supply_of_match[] = {
 370         {.compatible = "ti,omap-opp-supply", .data = &omap_generic_of_data},
 371         {.compatible = "ti,omap5-opp-supply", .data = &omap_omap5_of_data},
 372         {.compatible = "ti,omap5-core-opp-supply",
 373          .data = &omap_omap5core_of_data},
 374         {},
 375 };
 376 MODULE_DEVICE_TABLE(of, ti_opp_supply_of_match);
 377
 378 static int ti_opp_supply_probe(struct platform_device *pdev)
 379 {
 380         struct device *dev = &pdev->dev;
 381         struct device *cpu_dev = get_cpu_device(0);
 382         const struct of_device_id *match;
 383         const struct ti_opp_supply_of_data *of_data;
 384         int ret = 0;
 385
 386         match = of_match_device(ti_opp_supply_of_match, dev);
 387         if (!match) {
 388                 /* We do not expect this to happen */
 389                 dev_err(dev, "%s: Unable to match device\n", __func__);
 390                 return -ENODEV;
 391         }
 392         if (!match->data) {
 393                 /* Again, unlikely.. but mistakes do happen */
 394                 dev_err(dev, "%s: Bad data in match\n", __func__);
 395                 return -EINVAL;
 396         }
 397         of_data = match->data;
 398
 399         dev_set_drvdata(dev, (void *)of_data);
 400
 401         /* If we need optimized voltage */
 402         if (of_data->flags & OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE) {
 403                 ret = _store_optimized_voltages(dev, &opp_data);
 404                 if (ret)
 405                         return ret;
 406         }
 407
 408         ret = PTR_ERR_OR_ZERO(dev_pm_opp_register_set_opp_helper(cpu_dev,
 409                                                                  ti_opp_supply_set_opp));
 410         if (ret)
 411                 _free_optimized_voltages(dev, &opp_data);
 412
 413         return ret;
 414 }
 415
 416 static struct platform_driver ti_opp_supply_driver = {
 417         .probe = ti_opp_supply_probe,
 418         .driver = {
 419                    .name = "ti_opp_supply",
 420                    .owner = THIS_MODULE,
 421                    .of_match_table = of_match_ptr(ti_opp_supply_of_match),
 422                    },
 423 };
 424 module_platform_driver(ti_opp_supply_driver);
 425
 426 MODULE_DESCRIPTION("Texas Instruments OMAP OPP Supply driver");
 427 MODULE_AUTHOR("Texas Instruments Inc.");
 428 MODULE_LICENSE("GPL v2");