linux/drivers/regulator/anatop-regulator.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2//
   3// Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
   4
   5#include <linux/slab.h>
   6#include <linux/device.h>
   7#include <linux/module.h>
   8#include <linux/mfd/syscon.h>
   9#include <linux/err.h>
  10#include <linux/io.h>
  11#include <linux/platform_device.h>
  12#include <linux/of.h>
  13#include <linux/of_address.h>
  14#include <linux/regmap.h>
  15#include <linux/regulator/driver.h>
  16#include <linux/regulator/of_regulator.h>
  17#include <linux/regulator/machine.h>
  18
  19#define LDO_RAMP_UP_UNIT_IN_CYCLES      64 /* 64 cycles per step */
  20#define LDO_RAMP_UP_FREQ_IN_MHZ         24 /* cycle based on 24M OSC */
  21
  22#define LDO_POWER_GATE                  0x00
  23#define LDO_FET_FULL_ON                 0x1f
  24
  25struct anatop_regulator {
  26        u32 control_reg;
  27        struct regmap *anatop;
  28        int vol_bit_shift;
  29        int vol_bit_width;
  30        u32 delay_reg;
  31        int delay_bit_shift;
  32        int delay_bit_width;
  33        int min_bit_val;
  34        int min_voltage;
  35        int max_voltage;
  36        struct regulator_desc rdesc;
  37        struct regulator_init_data *initdata;
  38        bool bypass;
  39        int sel;
  40};
  41
  42static int anatop_regmap_set_voltage_time_sel(struct regulator_dev *reg,
  43        unsigned int old_sel,
  44        unsigned int new_sel)
  45{
  46        struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
  47        u32 val;
  48        int ret = 0;
  49
  50        /* check whether need to care about LDO ramp up speed */
  51        if (anatop_reg->delay_bit_width && new_sel > old_sel) {
  52                /*
  53                 * the delay for LDO ramp up time is
  54                 * based on the register setting, we need
  55                 * to calculate how many steps LDO need to
  56                 * ramp up, and how much delay needed. (us)
  57                 */
  58                regmap_read(anatop_reg->anatop, anatop_reg->delay_reg, &val);
  59                val = (val >> anatop_reg->delay_bit_shift) &
  60                        ((1 << anatop_reg->delay_bit_width) - 1);
  61                ret = (new_sel - old_sel) * (LDO_RAMP_UP_UNIT_IN_CYCLES <<
  62                        val) / LDO_RAMP_UP_FREQ_IN_MHZ + 1;
  63        }
  64
  65        return ret;
  66}
  67
  68static int anatop_regmap_enable(struct regulator_dev *reg)
  69{
  70        struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
  71        int sel;
  72
  73        sel = anatop_reg->bypass ? LDO_FET_FULL_ON : anatop_reg->sel;
  74        return regulator_set_voltage_sel_regmap(reg, sel);
  75}
  76
  77static int anatop_regmap_disable(struct regulator_dev *reg)
  78{
  79        return regulator_set_voltage_sel_regmap(reg, LDO_POWER_GATE);
  80}
  81
  82static int anatop_regmap_is_enabled(struct regulator_dev *reg)
  83{
  84        return regulator_get_voltage_sel_regmap(reg) != LDO_POWER_GATE;
  85}
  86
  87static int anatop_regmap_core_set_voltage_sel(struct regulator_dev *reg,
  88                                              unsigned selector)
  89{
  90        struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
  91        int ret;
  92
  93        if (anatop_reg->bypass || !anatop_regmap_is_enabled(reg)) {
  94                anatop_reg->sel = selector;
  95                return 0;
  96        }
  97
  98        ret = regulator_set_voltage_sel_regmap(reg, selector);
  99        if (!ret)
 100                anatop_reg->sel = selector;
 101        return ret;
 102}
 103
 104static int anatop_regmap_core_get_voltage_sel(struct regulator_dev *reg)
 105{
 106        struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
 107
 108        if (anatop_reg->bypass || !anatop_regmap_is_enabled(reg))
 109                return anatop_reg->sel;
 110
 111        return regulator_get_voltage_sel_regmap(reg);
 112}
 113
 114static int anatop_regmap_get_bypass(struct regulator_dev *reg, bool *enable)
 115{
 116        struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
 117        int sel;
 118
 119        sel = regulator_get_voltage_sel_regmap(reg);
 120        if (sel == LDO_FET_FULL_ON)
 121                WARN_ON(!anatop_reg->bypass);
 122        else if (sel != LDO_POWER_GATE)
 123                WARN_ON(anatop_reg->bypass);
 124
 125        *enable = anatop_reg->bypass;
 126        return 0;
 127}
 128
 129static int anatop_regmap_set_bypass(struct regulator_dev *reg, bool enable)
 130{
 131        struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
 132        int sel;
 133
 134        if (enable == anatop_reg->bypass)
 135                return 0;
 136
 137        sel = enable ? LDO_FET_FULL_ON : anatop_reg->sel;
 138        anatop_reg->bypass = enable;
 139
 140        return regulator_set_voltage_sel_regmap(reg, sel);
 141}
 142
 143static struct regulator_ops anatop_rops = {
 144        .set_voltage_sel = regulator_set_voltage_sel_regmap,
 145        .get_voltage_sel = regulator_get_voltage_sel_regmap,
 146        .list_voltage = regulator_list_voltage_linear,
 147        .map_voltage = regulator_map_voltage_linear,
 148};
 149
 150static struct regulator_ops anatop_core_rops = {
 151        .enable = anatop_regmap_enable,
 152        .disable = anatop_regmap_disable,
 153        .is_enabled = anatop_regmap_is_enabled,
 154        .set_voltage_sel = anatop_regmap_core_set_voltage_sel,
 155        .set_voltage_time_sel = anatop_regmap_set_voltage_time_sel,
 156        .get_voltage_sel = anatop_regmap_core_get_voltage_sel,
 157        .list_voltage = regulator_list_voltage_linear,
 158        .map_voltage = regulator_map_voltage_linear,
 159        .get_bypass = anatop_regmap_get_bypass,
 160        .set_bypass = anatop_regmap_set_bypass,
 161};
 162
 163static int anatop_regulator_probe(struct platform_device *pdev)
 164{
 165        struct device *dev = &pdev->dev;
 166        struct device_node *np = dev->of_node;
 167        struct device_node *anatop_np;
 168        struct regulator_desc *rdesc;
 169        struct regulator_dev *rdev;
 170        struct anatop_regulator *sreg;
 171        struct regulator_init_data *initdata;
 172        struct regulator_config config = { };
 173        int ret = 0;
 174        u32 val;
 175
 176        sreg = devm_kzalloc(dev, sizeof(*sreg), GFP_KERNEL);
 177        if (!sreg)
 178                return -ENOMEM;
 179
 180        rdesc = &sreg->rdesc;
 181        rdesc->type = REGULATOR_VOLTAGE;
 182        rdesc->owner = THIS_MODULE;
 183
 184        of_property_read_string(np, "regulator-name", &rdesc->name);
 185        if (!rdesc->name) {
 186                dev_err(dev, "failed to get a regulator-name\n");
 187                return -EINVAL;
 188        }
 189
 190        initdata = of_get_regulator_init_data(dev, np, rdesc);
 191        if (!initdata)
 192                return -ENOMEM;
 193
 194        initdata->supply_regulator = "vin";
 195        sreg->initdata = initdata;
 196
 197        anatop_np = of_get_parent(np);
 198        if (!anatop_np)
 199                return -ENODEV;
 200        sreg->anatop = syscon_node_to_regmap(anatop_np);
 201        of_node_put(anatop_np);
 202        if (IS_ERR(sreg->anatop))
 203                return PTR_ERR(sreg->anatop);
 204
 205        ret = of_property_read_u32(np, "anatop-reg-offset",
 206                                   &sreg->control_reg);
 207        if (ret) {
 208                dev_err(dev, "no anatop-reg-offset property set\n");
 209                return ret;
 210        }
 211        ret = of_property_read_u32(np, "anatop-vol-bit-width",
 212                                   &sreg->vol_bit_width);
 213        if (ret) {
 214                dev_err(dev, "no anatop-vol-bit-width property set\n");
 215                return ret;
 216        }
 217        ret = of_property_read_u32(np, "anatop-vol-bit-shift",
 218                                   &sreg->vol_bit_shift);
 219        if (ret) {
 220                dev_err(dev, "no anatop-vol-bit-shift property set\n");
 221                return ret;
 222        }
 223        ret = of_property_read_u32(np, "anatop-min-bit-val",
 224                                   &sreg->min_bit_val);
 225        if (ret) {
 226                dev_err(dev, "no anatop-min-bit-val property set\n");
 227                return ret;
 228        }
 229        ret = of_property_read_u32(np, "anatop-min-voltage",
 230                                   &sreg->min_voltage);
 231        if (ret) {
 232                dev_err(dev, "no anatop-min-voltage property set\n");
 233                return ret;
 234        }
 235        ret = of_property_read_u32(np, "anatop-max-voltage",
 236                                   &sreg->max_voltage);
 237        if (ret) {
 238                dev_err(dev, "no anatop-max-voltage property set\n");
 239                return ret;
 240        }
 241
 242        /* read LDO ramp up setting, only for core reg */
 243        of_property_read_u32(np, "anatop-delay-reg-offset",
 244                             &sreg->delay_reg);
 245        of_property_read_u32(np, "anatop-delay-bit-width",
 246                             &sreg->delay_bit_width);
 247        of_property_read_u32(np, "anatop-delay-bit-shift",
 248                             &sreg->delay_bit_shift);
 249
 250        rdesc->n_voltages = (sreg->max_voltage - sreg->min_voltage) / 25000 + 1
 251                            + sreg->min_bit_val;
 252        rdesc->min_uV = sreg->min_voltage;
 253        rdesc->uV_step = 25000;
 254        rdesc->linear_min_sel = sreg->min_bit_val;
 255        rdesc->vsel_reg = sreg->control_reg;
 256        rdesc->vsel_mask = ((1 << sreg->vol_bit_width) - 1) <<
 257                           sreg->vol_bit_shift;
 258        rdesc->min_dropout_uV = 125000;
 259
 260        config.dev = &pdev->dev;
 261        config.init_data = initdata;
 262        config.driver_data = sreg;
 263        config.of_node = pdev->dev.of_node;
 264        config.regmap = sreg->anatop;
 265
 266        /* Only core regulators have the ramp up delay configuration. */
 267        if (sreg->control_reg && sreg->delay_bit_width) {
 268                rdesc->ops = &anatop_core_rops;
 269
 270                ret = regmap_read(config.regmap, rdesc->vsel_reg, &val);
 271                if (ret) {
 272                        dev_err(dev, "failed to read initial state\n");
 273                        return ret;
 274                }
 275
 276                sreg->sel = (val & rdesc->vsel_mask) >> sreg->vol_bit_shift;
 277                if (sreg->sel == LDO_FET_FULL_ON) {
 278                        sreg->sel = 0;
 279                        sreg->bypass = true;
 280                }
 281
 282                /*
 283                 * In case vddpu was disabled by the bootloader, we need to set
 284                 * a sane default until imx6-cpufreq was probed and changes the
 285                 * voltage to the correct value. In this case we set 1.25V.
 286                 */
 287                if (!sreg->sel && !strcmp(rdesc->name, "vddpu"))
 288                        sreg->sel = 22;
 289
 290                /* set the default voltage of the pcie phy to be 1.100v */
 291                if (!sreg->sel && !strcmp(rdesc->name, "vddpcie"))
 292                        sreg->sel = 0x10;
 293
 294                if (!sreg->bypass && !sreg->sel) {
 295                        dev_err(&pdev->dev, "Failed to read a valid default voltage selector.\n");
 296                        return -EINVAL;
 297                }
 298        } else {
 299                u32 enable_bit;
 300
 301                rdesc->ops = &anatop_rops;
 302
 303                if (!of_property_read_u32(np, "anatop-enable-bit",
 304                                          &enable_bit)) {
 305                        anatop_rops.enable  = regulator_enable_regmap;
 306                        anatop_rops.disable = regulator_disable_regmap;
 307                        anatop_rops.is_enabled = regulator_is_enabled_regmap;
 308
 309                        rdesc->enable_reg = sreg->control_reg;
 310                        rdesc->enable_mask = BIT(enable_bit);
 311                }
 312        }
 313
 314        /* register regulator */
 315        rdev = devm_regulator_register(dev, rdesc, &config);
 316        if (IS_ERR(rdev)) {
 317                dev_err(dev, "failed to register %s\n",
 318                        rdesc->name);
 319                return PTR_ERR(rdev);
 320        }
 321
 322        platform_set_drvdata(pdev, rdev);
 323
 324        return 0;
 325}
 326
 327static const struct of_device_id of_anatop_regulator_match_tbl[] = {
 328        { .compatible = "fsl,anatop-regulator", },
 329        { /* end */ }
 330};
 331MODULE_DEVICE_TABLE(of, of_anatop_regulator_match_tbl);
 332
 333static struct platform_driver anatop_regulator_driver = {
 334        .driver = {
 335                .name   = "anatop_regulator",
 336                .of_match_table = of_anatop_regulator_match_tbl,
 337        },
 338        .probe  = anatop_regulator_probe,
 339};
 340
 341static int __init anatop_regulator_init(void)
 342{
 343        return platform_driver_register(&anatop_regulator_driver);
 344}
 345postcore_initcall(anatop_regulator_init);
 346
 347static void __exit anatop_regulator_exit(void)
 348{
 349        platform_driver_unregister(&anatop_regulator_driver);
 350}
 351module_exit(anatop_regulator_exit);
 352
 353MODULE_AUTHOR("Nancy Chen <Nancy.Chen@freescale.com>");
 354MODULE_AUTHOR("Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>");
 355MODULE_DESCRIPTION("ANATOP Regulator driver");
 356MODULE_LICENSE("GPL v2");
 357MODULE_ALIAS("platform:anatop_regulator");
 358