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