drivers/regulator/anatop-regulator.c

   1 /*
   2  * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
   3  */
   4
   5 /*
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #include <linux/slab.h>
  22 #include <linux/device.h>
  23 #include <linux/module.h>
  24 #include <linux/mfd/syscon.h>
  25 #include <linux/err.h>
  26 #include <linux/io.h>
  27 #include <linux/platform_device.h>
  28 #include <linux/of.h>
  29 #include <linux/of_address.h>
  30 #include <linux/regmap.h>
  31 #include <linux/regulator/driver.h>
  32 #include <linux/regulator/of_regulator.h>
  33
  34 #define LDO_RAMP_UP_UNIT_IN_CYCLES      64 /* 64 cycles per step */
  35 #define LDO_RAMP_UP_FREQ_IN_MHZ         24 /* cycle based on 24M OSC */
  36
  37 #define LDO_POWER_GATE                  0x00
  38 #define LDO_FET_FULL_ON                 0x1f
  39
  40 struct anatop_regulator {
  41         const char *name;
  42         u32 control_reg;
  43         struct regmap *anatop;
  44         int vol_bit_shift;
  45         int vol_bit_width;
  46         u32 delay_reg;
  47         int delay_bit_shift;
  48         int delay_bit_width;
  49         int min_bit_val;
  50         int min_voltage;
  51         int max_voltage;
  52         struct regulator_desc rdesc;
  53         struct regulator_init_data *initdata;
  54         bool bypass;
  55         int sel;
  56 };
  57
  58 static int anatop_regmap_set_voltage_time_sel(struct regulator_dev *reg,
  59         unsigned int old_sel,
  60         unsigned int new_sel)
  61 {
  62         struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
  63         u32 val;
  64         int ret = 0;
  65
  66         /* check whether need to care about LDO ramp up speed */
  67         if (anatop_reg->delay_bit_width && new_sel > old_sel) {
  68                 /*
  69                  * the delay for LDO ramp up time is
  70                  * based on the register setting, we need
  71                  * to calculate how many steps LDO need to
  72                  * ramp up, and how much delay needed. (us)
  73                  */
  74                 regmap_read(anatop_reg->anatop, anatop_reg->delay_reg, &val);
  75                 val = (val >> anatop_reg->delay_bit_shift) &
  76                         ((1 << anatop_reg->delay_bit_width) - 1);
  77                 ret = (new_sel - old_sel) * (LDO_RAMP_UP_UNIT_IN_CYCLES <<
  78                         val) / LDO_RAMP_UP_FREQ_IN_MHZ + 1;
  79         }
  80
  81         return ret;
  82 }
  83
  84 static int anatop_regmap_enable(struct regulator_dev *reg)
  85 {
  86         struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
  87         int sel;
  88
  89         sel = anatop_reg->bypass ? LDO_FET_FULL_ON : anatop_reg->sel;
  90         return regulator_set_voltage_sel_regmap(reg, sel);
  91 }
  92
  93 static int anatop_regmap_disable(struct regulator_dev *reg)
  94 {
  95         return regulator_set_voltage_sel_regmap(reg, LDO_POWER_GATE);
  96 }
  97
  98 static int anatop_regmap_is_enabled(struct regulator_dev *reg)
  99 {
 100         return regulator_get_voltage_sel_regmap(reg) != LDO_POWER_GATE;
 101 }
 102
 103 static int anatop_regmap_core_set_voltage_sel(struct regulator_dev *reg,
 104                                               unsigned selector)
 105 {
 106         struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
 107         int ret;
 108
 109         if (anatop_reg->bypass || !anatop_regmap_is_enabled(reg)) {
 110                 anatop_reg->sel = selector;
 111                 return 0;
 112         }
 113
 114         ret = regulator_set_voltage_sel_regmap(reg, selector);
 115         if (!ret)
 116                 anatop_reg->sel = selector;
 117         return ret;
 118 }
 119
 120 static int anatop_regmap_core_get_voltage_sel(struct regulator_dev *reg)
 121 {
 122         struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
 123
 124         if (anatop_reg->bypass || !anatop_regmap_is_enabled(reg))
 125                 return anatop_reg->sel;
 126
 127         return regulator_get_voltage_sel_regmap(reg);
 128 }
 129
 130 static int anatop_regmap_get_bypass(struct regulator_dev *reg, bool *enable)
 131 {
 132         struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
 133         int sel;
 134
 135         sel = regulator_get_voltage_sel_regmap(reg);
 136         if (sel == LDO_FET_FULL_ON)
 137                 WARN_ON(!anatop_reg->bypass);
 138         else if (sel != LDO_POWER_GATE)
 139                 WARN_ON(anatop_reg->bypass);
 140
 141         *enable = anatop_reg->bypass;
 142         return 0;
 143 }
 144
 145 static int anatop_regmap_set_bypass(struct regulator_dev *reg, bool enable)
 146 {
 147         struct anatop_regulator *anatop_reg = rdev_get_drvdata(reg);
 148         int sel;
 149
 150         if (enable == anatop_reg->bypass)
 151                 return 0;
 152
 153         sel = enable ? LDO_FET_FULL_ON : anatop_reg->sel;
 154         anatop_reg->bypass = enable;
 155
 156         return regulator_set_voltage_sel_regmap(reg, sel);
 157 }
 158
 159 static struct regulator_ops anatop_rops = {
 160         .set_voltage_sel = regulator_set_voltage_sel_regmap,
 161         .get_voltage_sel = regulator_get_voltage_sel_regmap,
 162         .list_voltage = regulator_list_voltage_linear,
 163         .map_voltage = regulator_map_voltage_linear,
 164 };
 165
 166 static struct regulator_ops anatop_core_rops = {
 167         .enable = anatop_regmap_enable,
 168         .disable = anatop_regmap_disable,
 169         .is_enabled = anatop_regmap_is_enabled,
 170         .set_voltage_sel = anatop_regmap_core_set_voltage_sel,
 171         .set_voltage_time_sel = anatop_regmap_set_voltage_time_sel,
 172         .get_voltage_sel = anatop_regmap_core_get_voltage_sel,
 173         .list_voltage = regulator_list_voltage_linear,
 174         .map_voltage = regulator_map_voltage_linear,
 175         .get_bypass = anatop_regmap_get_bypass,
 176         .set_bypass = anatop_regmap_set_bypass,
 177 };
 178
 179 static int anatop_regulator_probe(struct platform_device *pdev)
 180 {
 181         struct device *dev = &pdev->dev;
 182         struct device_node *np = dev->of_node;
 183         struct device_node *anatop_np;
 184         struct regulator_desc *rdesc;
 185         struct regulator_dev *rdev;
 186         struct anatop_regulator *sreg;
 187         struct regulator_init_data *initdata;
 188         struct regulator_config config = { };
 189         int ret = 0;
 190         u32 val;
 191
 192         sreg = devm_kzalloc(dev, sizeof(*sreg), GFP_KERNEL);
 193         if (!sreg)
 194                 return -ENOMEM;
 195         sreg->name = of_get_property(np, "regulator-name", NULL);
 196         rdesc = &sreg->rdesc;
 197         rdesc->name = sreg->name;
 198         rdesc->type = REGULATOR_VOLTAGE;
 199         rdesc->owner = THIS_MODULE;
 200
 201         initdata = of_get_regulator_init_data(dev, np, rdesc);
 202         sreg->initdata = initdata;
 203
 204         anatop_np = of_get_parent(np);
 205         if (!anatop_np)
 206                 return -ENODEV;
 207         sreg->anatop = syscon_node_to_regmap(anatop_np);
 208         of_node_put(anatop_np);
 209         if (IS_ERR(sreg->anatop))
 210                 return PTR_ERR(sreg->anatop);
 211
 212         ret = of_property_read_u32(np, "anatop-reg-offset",
 213                                    &sreg->control_reg);
 214         if (ret) {
 215                 dev_err(dev, "no anatop-reg-offset property set\n");
 216                 return ret;
 217         }
 218         ret = of_property_read_u32(np, "anatop-vol-bit-width",
 219                                    &sreg->vol_bit_width);
 220         if (ret) {
 221                 dev_err(dev, "no anatop-vol-bit-width property set\n");
 222                 return ret;
 223         }
 224         ret = of_property_read_u32(np, "anatop-vol-bit-shift",
 225                                    &sreg->vol_bit_shift);
 226         if (ret) {
 227                 dev_err(dev, "no anatop-vol-bit-shift property set\n");
 228                 return ret;
 229         }
 230         ret = of_property_read_u32(np, "anatop-min-bit-val",
 231                                    &sreg->min_bit_val);
 232         if (ret) {
 233                 dev_err(dev, "no anatop-min-bit-val property set\n");
 234                 return ret;
 235         }
 236         ret = of_property_read_u32(np, "anatop-min-voltage",
 237                                    &sreg->min_voltage);
 238         if (ret) {
 239                 dev_err(dev, "no anatop-min-voltage property set\n");
 240                 return ret;
 241         }
 242         ret = of_property_read_u32(np, "anatop-max-voltage",
 243                                    &sreg->max_voltage);
 244         if (ret) {
 245                 dev_err(dev, "no anatop-max-voltage property set\n");
 246                 return ret;
 247         }
 248
 249         /* read LDO ramp up setting, only for core reg */
 250         of_property_read_u32(np, "anatop-delay-reg-offset",
 251                              &sreg->delay_reg);
 252         of_property_read_u32(np, "anatop-delay-bit-width",
 253                              &sreg->delay_bit_width);
 254         of_property_read_u32(np, "anatop-delay-bit-shift",
 255                              &sreg->delay_bit_shift);
 256
 257         rdesc->n_voltages = (sreg->max_voltage - sreg->min_voltage) / 25000 + 1
 258                             + sreg->min_bit_val;
 259         rdesc->min_uV = sreg->min_voltage;
 260         rdesc->uV_step = 25000;
 261         rdesc->linear_min_sel = sreg->min_bit_val;
 262         rdesc->vsel_reg = sreg->control_reg;
 263         rdesc->vsel_mask = ((1 << sreg->vol_bit_width) - 1) <<
 264                            sreg->vol_bit_shift;
 265
 266         config.dev = &pdev->dev;
 267         config.init_data = initdata;
 268         config.driver_data = sreg;
 269         config.of_node = pdev->dev.of_node;
 270         config.regmap = sreg->anatop;
 271
 272         /* Only core regulators have the ramp up delay configuration. */
 273         if (sreg->control_reg && sreg->delay_bit_width) {
 274                 rdesc->ops = &anatop_core_rops;
 275
 276                 ret = regmap_read(config.regmap, rdesc->vsel_reg, &val);
 277                 if (ret) {
 278                         dev_err(dev, "failed to read initial state\n");
 279                         return ret;
 280                 }
 281
 282                 sreg->sel = (val & rdesc->vsel_mask) >> sreg->vol_bit_shift;
 283                 if (sreg->sel == LDO_FET_FULL_ON) {
 284                         sreg->sel = 0;
 285                         sreg->bypass = true;
 286                 }
 287
 288                 /*
 289                  * In case vddpu was disabled by the bootloader, we need to set
 290                  * a sane default until imx6-cpufreq was probed and changes the
 291                  * voltage to the correct value. In this case we set 1.25V.
 292                  */
 293                 if (!sreg->sel && !strcmp(sreg->name, "vddpu"))
 294                         sreg->sel = 22;
 295
 296                 if (!sreg->sel) {
 297                         dev_err(&pdev->dev, "Failed to read a valid default voltage selector.\n");
 298                         return -EINVAL;
 299                 }
 300         } else {
 301                 rdesc->ops = &anatop_rops;
 302         }
 303
 304         /* register regulator */
 305         rdev = devm_regulator_register(dev, rdesc, &config);
 306         if (IS_ERR(rdev)) {
 307                 dev_err(dev, "failed to register %s\n",
 308                         rdesc->name);
 309                 return PTR_ERR(rdev);
 310         }
 311
 312         platform_set_drvdata(pdev, rdev);
 313
 314         return 0;
 315 }
 316
 317 static const struct of_device_id of_anatop_regulator_match_tbl[] = {
 318         { .compatible = "fsl,anatop-regulator", },
 319         { /* end */ }
 320 };
 321
 322 static struct platform_driver anatop_regulator_driver = {
 323         .driver = {
 324                 .name   = "anatop_regulator",
 325                 .of_match_table = of_anatop_regulator_match_tbl,
 326         },
 327         .probe  = anatop_regulator_probe,
 328 };
 329
 330 static int __init anatop_regulator_init(void)
 331 {
 332         return platform_driver_register(&anatop_regulator_driver);
 333 }
 334 postcore_initcall(anatop_regulator_init);
 335
 336 static void __exit anatop_regulator_exit(void)
 337 {
 338         platform_driver_unregister(&anatop_regulator_driver);
 339 }
 340 module_exit(anatop_regulator_exit);
 341
 342 MODULE_AUTHOR("Nancy Chen <Nancy.Chen@freescale.com>");
 343 MODULE_AUTHOR("Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>");
 344 MODULE_DESCRIPTION("ANATOP Regulator driver");
 345 MODULE_LICENSE("GPL v2");
 346 MODULE_ALIAS("platform:anatop_regulator");