drivers/regulator/max14577.c

   1 /*
   2  * max14577.c - Regulator driver for the Maxim 14577
   3  *
   4  * Copyright (C) 2013 Samsung Electronics
   5  * Krzysztof Kozlowski <k.kozlowski@samsung.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #include <linux/module.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/regulator/driver.h>
  21 #include <linux/mfd/max14577.h>
  22 #include <linux/mfd/max14577-private.h>
  23 #include <linux/regulator/of_regulator.h>
  24
  25 struct max14577_regulator {
  26         struct device *dev;
  27         struct max14577 *max14577;
  28         struct regulator_dev **regulators;
  29 };
  30
  31 static int max14577_reg_is_enabled(struct regulator_dev *rdev)
  32 {
  33         int rid = rdev_get_id(rdev);
  34         struct regmap *rmap = rdev->regmap;
  35         u8 reg_data;
  36
  37         switch (rid) {
  38         case MAX14577_CHARGER:
  39                 max14577_read_reg(rmap, MAX14577_CHG_REG_CHG_CTRL2, &reg_data);
  40                 if ((reg_data & CHGCTRL2_MBCHOSTEN_MASK) == 0)
  41                         return 0;
  42                 max14577_read_reg(rmap, MAX14577_CHG_REG_STATUS3, &reg_data);
  43                 if ((reg_data & STATUS3_CGMBC_MASK) == 0)
  44                         return 0;
  45                 /* MBCHOSTEN and CGMBC are on */
  46                 return 1;
  47         default:
  48                 return -EINVAL;
  49         }
  50 }
  51
  52 static int max14577_reg_get_current_limit(struct regulator_dev *rdev)
  53 {
  54         u8 reg_data;
  55         struct regmap *rmap = rdev->regmap;
  56
  57         if (rdev_get_id(rdev) != MAX14577_CHARGER)
  58                 return -EINVAL;
  59
  60         max14577_read_reg(rmap, MAX14577_CHG_REG_CHG_CTRL4, &reg_data);
  61
  62         if ((reg_data & CHGCTRL4_MBCICHWRCL_MASK) == 0)
  63                 return MAX14577_REGULATOR_CURRENT_LIMIT_MIN;
  64
  65         reg_data = ((reg_data & CHGCTRL4_MBCICHWRCH_MASK) >>
  66                         CHGCTRL4_MBCICHWRCH_SHIFT);
  67         return MAX14577_REGULATOR_CURRENT_LIMIT_HIGH_START +
  68                 reg_data * MAX14577_REGULATOR_CURRENT_LIMIT_HIGH_STEP;
  69 }
  70
  71 static int max14577_reg_set_current_limit(struct regulator_dev *rdev,
  72                 int min_uA, int max_uA)
  73 {
  74         int i, current_bits = 0xf;
  75         u8 reg_data;
  76
  77         if (rdev_get_id(rdev) != MAX14577_CHARGER)
  78                 return -EINVAL;
  79
  80         if (min_uA > MAX14577_REGULATOR_CURRENT_LIMIT_MAX ||
  81                         max_uA < MAX14577_REGULATOR_CURRENT_LIMIT_MIN)
  82                 return -EINVAL;
  83
  84         if (max_uA < MAX14577_REGULATOR_CURRENT_LIMIT_HIGH_START) {
  85                 /* Less than 200 mA, so set 90mA (turn only Low Bit off) */
  86                 u8 reg_data = 0x0 << CHGCTRL4_MBCICHWRCL_SHIFT;
  87                 return max14577_update_reg(rdev->regmap,
  88                                 MAX14577_CHG_REG_CHG_CTRL4,
  89                                 CHGCTRL4_MBCICHWRCL_MASK, reg_data);
  90         }
  91
  92         /* max_uA is in range: <LIMIT_HIGH_START, inifinite>, so search for
  93          * valid current starting from LIMIT_MAX. */
  94         for (i = MAX14577_REGULATOR_CURRENT_LIMIT_MAX;
  95                         i >= MAX14577_REGULATOR_CURRENT_LIMIT_HIGH_START;
  96                         i -= MAX14577_REGULATOR_CURRENT_LIMIT_HIGH_STEP) {
  97                 if (i <= max_uA)
  98                         break;
  99                 current_bits--;
 100         }
 101         BUG_ON(current_bits < 0); /* Cannot happen */
 102         /* Turn Low Bit on (use range 200mA-950 mA) */
 103         reg_data = 0x1 << CHGCTRL4_MBCICHWRCL_SHIFT;
 104         /* and set proper High Bits */
 105         reg_data |= current_bits << CHGCTRL4_MBCICHWRCH_SHIFT;
 106
 107         return max14577_update_reg(rdev->regmap, MAX14577_CHG_REG_CHG_CTRL4,
 108                         CHGCTRL4_MBCICHWRCL_MASK | CHGCTRL4_MBCICHWRCH_MASK,
 109                         reg_data);
 110 }
 111
 112 static struct regulator_ops max14577_safeout_ops = {
 113         .is_enabled             = regulator_is_enabled_regmap,
 114         .enable                 = regulator_enable_regmap,
 115         .disable                = regulator_disable_regmap,
 116         .list_voltage           = regulator_list_voltage_linear,
 117 };
 118
 119 static struct regulator_ops max14577_charger_ops = {
 120         .is_enabled             = max14577_reg_is_enabled,
 121         .enable                 = regulator_enable_regmap,
 122         .disable                = regulator_disable_regmap,
 123         .get_current_limit      = max14577_reg_get_current_limit,
 124         .set_current_limit      = max14577_reg_set_current_limit,
 125 };
 126
 127 static const struct regulator_desc supported_regulators[] = {
 128         [MAX14577_SAFEOUT] = {
 129                 .name           = "SAFEOUT",
 130                 .id             = MAX14577_SAFEOUT,
 131                 .ops            = &max14577_safeout_ops,
 132                 .type           = REGULATOR_VOLTAGE,
 133                 .owner          = THIS_MODULE,
 134                 .n_voltages     = 1,
 135                 .min_uV         = MAX14577_REGULATOR_SAFEOUT_VOLTAGE,
 136                 .enable_reg     = MAX14577_REG_CONTROL2,
 137                 .enable_mask    = CTRL2_SFOUTORD_MASK,
 138         },
 139         [MAX14577_CHARGER] = {
 140                 .name           = "CHARGER",
 141                 .id             = MAX14577_CHARGER,
 142                 .ops            = &max14577_charger_ops,
 143                 .type           = REGULATOR_CURRENT,
 144                 .owner          = THIS_MODULE,
 145                 .enable_reg     = MAX14577_CHG_REG_CHG_CTRL2,
 146                 .enable_mask    = CHGCTRL2_MBCHOSTEN_MASK,
 147         },
 148 };
 149
 150 #ifdef CONFIG_OF
 151 static struct of_regulator_match max14577_regulator_matches[] = {
 152         { .name = "SAFEOUT", },
 153         { .name = "CHARGER", },
 154 };
 155
 156 static int max14577_regulator_dt_parse_pdata(struct platform_device *pdev)
 157 {
 158         int ret;
 159         struct device_node *np;
 160
 161         np = of_get_child_by_name(pdev->dev.parent->of_node, "regulators");
 162         if (!np) {
 163                 dev_err(&pdev->dev, "Failed to get child OF node for regulators\n");
 164                 return -EINVAL;
 165         }
 166
 167         ret = of_regulator_match(&pdev->dev, np, max14577_regulator_matches,
 168                         MAX14577_REG_MAX);
 169         if (ret < 0)
 170                 dev_err(&pdev->dev, "Error parsing regulator init data: %d\n", ret);
 171         else
 172                 ret = 0;
 173
 174         of_node_put(np);
 175
 176         return ret;
 177 }
 178
 179 static inline struct regulator_init_data *match_init_data(int index)
 180 {
 181         return max14577_regulator_matches[index].init_data;
 182 }
 183
 184 static inline struct device_node *match_of_node(int index)
 185 {
 186         return max14577_regulator_matches[index].of_node;
 187 }
 188 #else /* CONFIG_OF */
 189 static int max14577_regulator_dt_parse_pdata(struct platform_device *pdev)
 190 {
 191         return 0;
 192 }
 193 static inline struct regulator_init_data *match_init_data(int index)
 194 {
 195         return NULL;
 196 }
 197
 198 static inline struct device_node *match_of_node(int index)
 199 {
 200         return NULL;
 201 }
 202 #endif /* CONFIG_OF */
 203
 204
 205 static int max14577_regulator_probe(struct platform_device *pdev)
 206 {
 207         struct max14577 *max14577 = dev_get_drvdata(pdev->dev.parent);
 208         struct max14577_platform_data *pdata = dev_get_platdata(max14577->dev);
 209         int i, ret;
 210         struct regulator_config config = {};
 211
 212         ret = max14577_regulator_dt_parse_pdata(pdev);
 213         if (ret)
 214                 return ret;
 215
 216         config.dev = &pdev->dev;
 217         config.regmap = max14577->regmap;
 218
 219         for (i = 0; i < ARRAY_SIZE(supported_regulators); i++) {
 220                 struct regulator_dev *regulator;
 221                 /*
 222                  * Index of supported_regulators[] is also the id and must
 223                  * match index of pdata->regulators[].
 224                  */
 225                 if (pdata && pdata->regulators) {
 226                         config.init_data = pdata->regulators[i].initdata;
 227                         config.of_node = pdata->regulators[i].of_node;
 228                 } else {
 229                         config.init_data = match_init_data(i);
 230                         config.of_node = match_of_node(i);
 231                 }
 232
 233                 regulator = devm_regulator_register(&pdev->dev,
 234                                 &supported_regulators[i], &config);
 235                 if (IS_ERR(regulator)) {
 236                         ret = PTR_ERR(regulator);
 237                         dev_err(&pdev->dev,
 238                                         "Regulator init failed for ID %d with error: %d\n",
 239                                         i, ret);
 240                         return ret;
 241                 }
 242         }
 243
 244         return ret;
 245 }
 246
 247 static struct platform_driver max14577_regulator_driver = {
 248         .driver = {
 249                    .owner = THIS_MODULE,
 250                    .name = "max14577-regulator",
 251                    },
 252         .probe  = max14577_regulator_probe,
 253 };
 254
 255 static int __init max14577_regulator_init(void)
 256 {
 257         BUILD_BUG_ON(MAX14577_REGULATOR_CURRENT_LIMIT_HIGH_START +
 258                         MAX14577_REGULATOR_CURRENT_LIMIT_HIGH_STEP * 0xf !=
 259                         MAX14577_REGULATOR_CURRENT_LIMIT_MAX);
 260         BUILD_BUG_ON(ARRAY_SIZE(supported_regulators) != MAX14577_REG_MAX);
 261
 262         return platform_driver_register(&max14577_regulator_driver);
 263 }
 264 subsys_initcall(max14577_regulator_init);
 265
 266 static void __exit max14577_regulator_exit(void)
 267 {
 268         platform_driver_unregister(&max14577_regulator_driver);
 269 }
 270 module_exit(max14577_regulator_exit);
 271
 272 MODULE_AUTHOR("Krzysztof Kozlowski <k.kozlowski@samsung.com>");
 273 MODULE_DESCRIPTION("MAXIM 14577 regulator driver");
 274 MODULE_LICENSE("GPL");
 275 MODULE_ALIAS("platform:max14577-regulator");