drivers/regulator/da9210-regulator.c

   1 /*
   2  * da9210-regulator.c - Regulator device driver for DA9210
   3  * Copyright (C) 2013  Dialog Semiconductor Ltd.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Library General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Library General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Library General Public
  16  * License along with this library; if not, write to the
  17  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
  18  * Boston, MA  02110-1301, USA.
  19  */
  20
  21 #include <linux/err.h>
  22 #include <linux/i2c.h>
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/irq.h>
  27 #include <linux/slab.h>
  28 #include <linux/regulator/driver.h>
  29 #include <linux/regulator/machine.h>
  30 #include <linux/regulator/of_regulator.h>
  31 #include <linux/regmap.h>
  32
  33 #include "da9210-regulator.h"
  34
  35 struct da9210 {
  36         struct regulator_dev *rdev;
  37         struct regmap *regmap;
  38 };
  39
  40 static const struct regmap_config da9210_regmap_config = {
  41         .reg_bits = 8,
  42         .val_bits = 8,
  43 };
  44
  45 static int da9210_set_current_limit(struct regulator_dev *rdev, int min_uA,
  46                                     int max_uA);
  47 static int da9210_get_current_limit(struct regulator_dev *rdev);
  48
  49 static const struct regulator_ops da9210_buck_ops = {
  50         .enable = regulator_enable_regmap,
  51         .disable = regulator_disable_regmap,
  52         .is_enabled = regulator_is_enabled_regmap,
  53         .set_voltage_sel = regulator_set_voltage_sel_regmap,
  54         .get_voltage_sel = regulator_get_voltage_sel_regmap,
  55         .list_voltage = regulator_list_voltage_linear,
  56         .set_current_limit = da9210_set_current_limit,
  57         .get_current_limit = da9210_get_current_limit,
  58 };
  59
  60 /* Default limits measured in millivolts and milliamps */
  61 #define DA9210_MIN_MV           300
  62 #define DA9210_MAX_MV           1570
  63 #define DA9210_STEP_MV          10
  64
  65 /* Current limits for buck (uA) indices corresponds with register values */
  66 static const int da9210_buck_limits[] = {
  67         1600000, 1800000, 2000000, 2200000, 2400000, 2600000, 2800000, 3000000,
  68         3200000, 3400000, 3600000, 3800000, 4000000, 4200000, 4400000, 4600000
  69 };
  70
  71 static const struct regulator_desc da9210_reg = {
  72         .name = "DA9210",
  73         .id = 0,
  74         .ops = &da9210_buck_ops,
  75         .type = REGULATOR_VOLTAGE,
  76         .n_voltages = ((DA9210_MAX_MV - DA9210_MIN_MV) / DA9210_STEP_MV) + 1,
  77         .min_uV = (DA9210_MIN_MV * 1000),
  78         .uV_step = (DA9210_STEP_MV * 1000),
  79         .vsel_reg = DA9210_REG_VBUCK_A,
  80         .vsel_mask = DA9210_VBUCK_MASK,
  81         .enable_reg = DA9210_REG_BUCK_CONT,
  82         .enable_mask = DA9210_BUCK_EN,
  83         .owner = THIS_MODULE,
  84 };
  85
  86 static int da9210_set_current_limit(struct regulator_dev *rdev, int min_uA,
  87                                     int max_uA)
  88 {
  89         struct da9210 *chip = rdev_get_drvdata(rdev);
  90         unsigned int sel;
  91         int i;
  92
  93         /* search for closest to maximum */
  94         for (i = ARRAY_SIZE(da9210_buck_limits)-1; i >= 0; i--) {
  95                 if (min_uA <= da9210_buck_limits[i] &&
  96                     max_uA >= da9210_buck_limits[i]) {
  97                         sel = i;
  98                         sel = sel << DA9210_BUCK_ILIM_SHIFT;
  99                         return regmap_update_bits(chip->regmap,
 100                                                   DA9210_REG_BUCK_ILIM,
 101                                                   DA9210_BUCK_ILIM_MASK, sel);
 102                 }
 103         }
 104
 105         return -EINVAL;
 106 }
 107
 108 static int da9210_get_current_limit(struct regulator_dev *rdev)
 109 {
 110         struct da9210 *chip = rdev_get_drvdata(rdev);
 111         unsigned int data;
 112         unsigned int sel;
 113         int ret;
 114
 115         ret = regmap_read(chip->regmap, DA9210_REG_BUCK_ILIM, &data);
 116         if (ret < 0)
 117                 return ret;
 118
 119         /* select one of 16 values: 0000 (1600mA) to 1111 (4600mA) */
 120         sel = (data & DA9210_BUCK_ILIM_MASK) >> DA9210_BUCK_ILIM_SHIFT;
 121
 122         return da9210_buck_limits[sel];
 123 }
 124
 125 static irqreturn_t da9210_irq_handler(int irq, void *data)
 126 {
 127         struct da9210 *chip = data;
 128         unsigned int val, handled = 0;
 129         int error, ret = IRQ_NONE;
 130
 131         error = regmap_read(chip->regmap, DA9210_REG_EVENT_B, &val);
 132         if (error < 0)
 133                 goto error_i2c;
 134
 135         mutex_lock(&chip->rdev->mutex);
 136
 137         if (val & DA9210_E_OVCURR) {
 138                 regulator_notifier_call_chain(chip->rdev,
 139                                               REGULATOR_EVENT_OVER_CURRENT,
 140                                               NULL);
 141                 handled |= DA9210_E_OVCURR;
 142         }
 143         if (val & DA9210_E_NPWRGOOD) {
 144                 regulator_notifier_call_chain(chip->rdev,
 145                                               REGULATOR_EVENT_UNDER_VOLTAGE,
 146                                               NULL);
 147                 handled |= DA9210_E_NPWRGOOD;
 148         }
 149         if (val & (DA9210_E_TEMP_WARN | DA9210_E_TEMP_CRIT)) {
 150                 regulator_notifier_call_chain(chip->rdev,
 151                                               REGULATOR_EVENT_OVER_TEMP, NULL);
 152                 handled |= val & (DA9210_E_TEMP_WARN | DA9210_E_TEMP_CRIT);
 153         }
 154         if (val & DA9210_E_VMAX) {
 155                 regulator_notifier_call_chain(chip->rdev,
 156                                               REGULATOR_EVENT_REGULATION_OUT,
 157                                               NULL);
 158                 handled |= DA9210_E_VMAX;
 159         }
 160
 161         mutex_unlock(&chip->rdev->mutex);
 162
 163         if (handled) {
 164                 /* Clear handled events */
 165                 error = regmap_write(chip->regmap, DA9210_REG_EVENT_B, handled);
 166                 if (error < 0)
 167                         goto error_i2c;
 168
 169                 ret = IRQ_HANDLED;
 170         }
 171
 172         return ret;
 173
 174 error_i2c:
 175         dev_err(regmap_get_device(chip->regmap), "I2C error : %d\n", error);
 176         return ret;
 177 }
 178
 179 /*
 180  * I2C driver interface functions
 181  */
 182 static int da9210_i2c_probe(struct i2c_client *i2c,
 183                             const struct i2c_device_id *id)
 184 {
 185         struct da9210 *chip;
 186         struct device *dev = &i2c->dev;
 187         struct da9210_pdata *pdata = dev_get_platdata(dev);
 188         struct regulator_dev *rdev = NULL;
 189         struct regulator_config config = { };
 190         int error;
 191
 192         chip = devm_kzalloc(&i2c->dev, sizeof(struct da9210), GFP_KERNEL);
 193         if (!chip)
 194                 return -ENOMEM;
 195
 196         chip->regmap = devm_regmap_init_i2c(i2c, &da9210_regmap_config);
 197         if (IS_ERR(chip->regmap)) {
 198                 error = PTR_ERR(chip->regmap);
 199                 dev_err(&i2c->dev, "Failed to allocate register map: %d\n",
 200                         error);
 201                 return error;
 202         }
 203
 204         config.dev = &i2c->dev;
 205         config.init_data = pdata ? &pdata->da9210_constraints :
 206                 of_get_regulator_init_data(dev, dev->of_node, &da9210_reg);
 207         config.driver_data = chip;
 208         config.regmap = chip->regmap;
 209         config.of_node = dev->of_node;
 210
 211         /* Mask all interrupt sources to deassert interrupt line */
 212         error = regmap_write(chip->regmap, DA9210_REG_MASK_A, ~0);
 213         if (!error)
 214                 error = regmap_write(chip->regmap, DA9210_REG_MASK_B, ~0);
 215         if (error) {
 216                 dev_err(&i2c->dev, "Failed to write to mask reg: %d\n", error);
 217                 return error;
 218         }
 219
 220         rdev = devm_regulator_register(&i2c->dev, &da9210_reg, &config);
 221         if (IS_ERR(rdev)) {
 222                 dev_err(&i2c->dev, "Failed to register DA9210 regulator\n");
 223                 return PTR_ERR(rdev);
 224         }
 225
 226         chip->rdev = rdev;
 227         if (i2c->irq) {
 228                 error = devm_request_threaded_irq(&i2c->dev, i2c->irq, NULL,
 229                                                   da9210_irq_handler,
 230                                                   IRQF_TRIGGER_LOW |
 231                                                   IRQF_ONESHOT | IRQF_SHARED,
 232                                                   "da9210", chip);
 233                 if (error) {
 234                         dev_err(&i2c->dev, "Failed to request IRQ%u: %d\n",
 235                                 i2c->irq, error);
 236                         return error;
 237                 }
 238
 239                 error = regmap_update_bits(chip->regmap, DA9210_REG_MASK_B,
 240                                          DA9210_M_OVCURR | DA9210_M_NPWRGOOD |
 241                                          DA9210_M_TEMP_WARN |
 242                                          DA9210_M_TEMP_CRIT | DA9210_M_VMAX, 0);
 243                 if (error < 0) {
 244                         dev_err(&i2c->dev, "Failed to update mask reg: %d\n",
 245                                 error);
 246                         return error;
 247                 }
 248         } else {
 249                 dev_warn(&i2c->dev, "No IRQ configured\n");
 250         }
 251
 252         i2c_set_clientdata(i2c, chip);
 253
 254         return 0;
 255 }
 256
 257 static const struct i2c_device_id da9210_i2c_id[] = {
 258         {"da9210", 0},
 259         {},
 260 };
 261
 262 MODULE_DEVICE_TABLE(i2c, da9210_i2c_id);
 263
 264 static struct i2c_driver da9210_regulator_driver = {
 265         .driver = {
 266                 .name = "da9210",
 267         },
 268         .probe = da9210_i2c_probe,
 269         .id_table = da9210_i2c_id,
 270 };
 271
 272 module_i2c_driver(da9210_regulator_driver);
 273
 274 MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
 275 MODULE_DESCRIPTION("Regulator device driver for Dialog DA9210");
 276 MODULE_LICENSE("GPL v2");