drivers/regulator/ltc3676.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (C) 2016 Gateworks Corporation, Inc. All Rights Reserved.
0004  */
0005 #include <linux/i2c.h>
0006 #include <linux/init.h>
0007 #include <linux/interrupt.h>
0008 #include <linux/module.h>
0009 #include <linux/kernel.h>
0010 #include <linux/of.h>
0011 #include <linux/regmap.h>
0012 #include <linux/regulator/driver.h>
0013 #include <linux/regulator/machine.h>
0014 #include <linux/regulator/of_regulator.h>
0015
0016 #define DRIVER_NAME     "ltc3676"
0017
0018 /* LTC3676 Registers */
0019 #define LTC3676_BUCK1     0x01
0020 #define LTC3676_BUCK2     0x02
0021 #define LTC3676_BUCK3     0x03
0022 #define LTC3676_BUCK4     0x04
0023 #define LTC3676_LDOA      0x05
0024 #define LTC3676_LDOB      0x06
0025 #define LTC3676_SQD1      0x07
0026 #define LTC3676_SQD2      0x08
0027 #define LTC3676_CNTRL     0x09
0028 #define LTC3676_DVB1A     0x0A
0029 #define LTC3676_DVB1B     0x0B
0030 #define LTC3676_DVB2A     0x0C
0031 #define LTC3676_DVB2B     0x0D
0032 #define LTC3676_DVB3A     0x0E
0033 #define LTC3676_DVB3B     0x0F
0034 #define LTC3676_DVB4A     0x10
0035 #define LTC3676_DVB4B     0x11
0036 #define LTC3676_MSKIRQ    0x12
0037 #define LTC3676_MSKPG     0x13
0038 #define LTC3676_USER      0x14
0039 #define LTC3676_IRQSTAT   0x15
0040 #define LTC3676_PGSTATL   0x16
0041 #define LTC3676_PGSTATRT  0x17
0042 #define LTC3676_HRST      0x1E
0043 #define LTC3676_CLIRQ     0x1F
0044
0045 #define LTC3676_DVBxA_REF_SELECT    BIT(5)
0046 #define LTC3676_DVBxB_PGOOD_MASK    BIT(5)
0047
0048 #define LTC3676_IRQSTAT_PGOOD_TIMEOUT   BIT(3)
0049 #define LTC3676_IRQSTAT_UNDERVOLT_WARN  BIT(4)
0050 #define LTC3676_IRQSTAT_UNDERVOLT_FAULT BIT(5)
0051 #define LTC3676_IRQSTAT_THERMAL_WARN    BIT(6)
0052 #define LTC3676_IRQSTAT_THERMAL_FAULT   BIT(7)
0053
0054 enum ltc3676_reg {
0055     LTC3676_SW1,
0056     LTC3676_SW2,
0057     LTC3676_SW3,
0058     LTC3676_SW4,
0059     LTC3676_LDO1,
0060     LTC3676_LDO2,
0061     LTC3676_LDO3,
0062     LTC3676_LDO4,
0063     LTC3676_NUM_REGULATORS,
0064 };
0065
0066 struct ltc3676 {
0067     struct regmap *regmap;
0068     struct device *dev;
0069     struct regulator_desc regulator_descs[LTC3676_NUM_REGULATORS];
0070     struct regulator_dev *regulators[LTC3676_NUM_REGULATORS];
0071 };
0072
0073 static int ltc3676_set_suspend_voltage(struct regulator_dev *rdev, int uV)
0074 {
0075     struct ltc3676 *ltc3676 = rdev_get_drvdata(rdev);
0076     struct device *dev = ltc3676->dev;
0077     int dcdc = rdev_get_id(rdev);
0078     int sel;
0079
0080     dev_dbg(dev, "%s id=%d uV=%d\n", __func__, dcdc, uV);
0081     sel = regulator_map_voltage_linear(rdev, uV, uV);
0082     if (sel < 0)
0083         return sel;
0084
0085     /* DVBB register follows right after the corresponding DVBA register */
0086     return regmap_update_bits(ltc3676->regmap, rdev->desc->vsel_reg + 1,
0087                   rdev->desc->vsel_mask, sel);
0088 }
0089
0090 static int ltc3676_set_suspend_mode(struct regulator_dev *rdev,
0091                     unsigned int mode)
0092 {
0093     struct ltc3676 *ltc3676= rdev_get_drvdata(rdev);
0094     struct device *dev = ltc3676->dev;
0095     int mask, val;
0096     int dcdc = rdev_get_id(rdev);
0097
0098     dev_dbg(dev, "%s id=%d mode=%d\n", __func__, dcdc, mode);
0099
0100     mask = LTC3676_DVBxA_REF_SELECT;
0101     switch (mode) {
0102     case REGULATOR_MODE_STANDBY:
0103         val = 0; /* select DVBxA */
0104         break;
0105     case REGULATOR_MODE_NORMAL:
0106         val = LTC3676_DVBxA_REF_SELECT; /* select DVBxB */
0107         break;
0108     default:
0109         dev_warn(&rdev->dev, "%s: regulator mode: 0x%x not supported\n",
0110              rdev->desc->name, mode);
0111         return -EINVAL;
0112     }
0113
0114     return regmap_update_bits(ltc3676->regmap, rdev->desc->vsel_reg,
0115                   mask, val);
0116 }
0117
0118 static int ltc3676_set_voltage_sel(struct regulator_dev *rdev, unsigned selector)
0119 {
0120     struct ltc3676 *ltc3676 = rdev_get_drvdata(rdev);
0121     struct device *dev = ltc3676->dev;
0122     int ret, dcdc = rdev_get_id(rdev);
0123
0124     dev_dbg(dev, "%s id=%d selector=%d\n", __func__, dcdc, selector);
0125
0126     ret = regmap_update_bits(ltc3676->regmap, rdev->desc->vsel_reg + 1,
0127                  LTC3676_DVBxB_PGOOD_MASK,
0128                  LTC3676_DVBxB_PGOOD_MASK);
0129     if (ret)
0130         return ret;
0131
0132     return regulator_set_voltage_sel_regmap(rdev, selector);
0133 }
0134
0135 static inline unsigned int ltc3676_scale(unsigned int uV, u32 r1, u32 r2)
0136 {
0137     uint64_t tmp;
0138     if (uV == 0)
0139         return 0;
0140     tmp = (uint64_t)uV * r1;
0141     do_div(tmp, r2);
0142     return uV + (unsigned int)tmp;
0143 }
0144
0145 static int ltc3676_of_parse_cb(struct device_node *np,
0146                    const struct regulator_desc *desc,
0147                    struct regulator_config *config)
0148 {
0149     struct ltc3676 *ltc3676 = config->driver_data;
0150     struct regulator_desc *rdesc = &ltc3676->regulator_descs[desc->id];
0151     u32 r[2];
0152     int ret;
0153
0154     /* LDO3 has a fixed output */
0155     if (desc->id == LTC3676_LDO3)
0156         return 0;
0157
0158     ret = of_property_read_u32_array(np, "lltc,fb-voltage-divider", r, 2);
0159     if (ret) {
0160         dev_err(ltc3676->dev, "Failed to parse voltage divider: %d\n",
0161             ret);
0162         return ret;
0163     }
0164
0165     rdesc->min_uV = ltc3676_scale(desc->min_uV, r[0], r[1]);
0166     rdesc->uV_step = ltc3676_scale(desc->uV_step, r[0], r[1]);
0167     rdesc->fixed_uV = ltc3676_scale(desc->fixed_uV, r[0], r[1]);
0168
0169     return 0;
0170 }
0171
0172 /* SW1, SW2, SW3, SW4 linear 0.8V-3.3V with scalar via R1/R2 feeback res */
0173 static const struct regulator_ops ltc3676_linear_regulator_ops = {
0174     .enable = regulator_enable_regmap,
0175     .disable = regulator_disable_regmap,
0176     .is_enabled = regulator_is_enabled_regmap,
0177     .list_voltage = regulator_list_voltage_linear,
0178     .set_voltage_sel = ltc3676_set_voltage_sel,
0179     .get_voltage_sel = regulator_get_voltage_sel_regmap,
0180     .set_suspend_voltage = ltc3676_set_suspend_voltage,
0181     .set_suspend_mode = ltc3676_set_suspend_mode,
0182 };
0183
0184 /* LDO1 always on fixed 0.8V-3.3V via scalar via R1/R2 feeback res */
0185 static const struct regulator_ops ltc3676_fixed_standby_regulator_ops = {
0186 };
0187
0188 /* LDO2, LDO3 fixed (LDO2 has external scalar via R1/R2 feedback res) */
0189 static const struct regulator_ops ltc3676_fixed_regulator_ops = {
0190     .enable = regulator_enable_regmap,
0191     .disable = regulator_disable_regmap,
0192     .is_enabled = regulator_is_enabled_regmap,
0193 };
0194
0195 #define LTC3676_REG(_id, _name, _ops, en_reg, en_bit, dvba_reg, dvb_mask)   \
0196     [LTC3676_ ## _id] = {                                        \
0197         .name = #_name,                                \
0198         .of_match = of_match_ptr(#_name),              \
0199         .regulators_node = of_match_ptr("regulators"), \
0200         .of_parse_cb = ltc3676_of_parse_cb,            \
0201         .n_voltages = (dvb_mask) + 1,                  \
0202         .min_uV = (dvba_reg) ? 412500 : 0,             \
0203         .uV_step = (dvba_reg) ? 12500 : 0,             \
0204         .ramp_delay = (dvba_reg) ? 800 : 0,            \
0205         .fixed_uV = (dvb_mask) ? 0 : 725000,           \
0206         .ops = &ltc3676_ ## _ops ## _regulator_ops,    \
0207         .type = REGULATOR_VOLTAGE,                     \
0208         .id = LTC3676_ ## _id,                         \
0209         .owner = THIS_MODULE,                          \
0210         .vsel_reg = (dvba_reg),                        \
0211         .vsel_mask = (dvb_mask),                       \
0212         .enable_reg = (en_reg),                        \
0213         .enable_mask = (1 << en_bit),                  \
0214     }
0215
0216 #define LTC3676_LINEAR_REG(_id, _name, _en, _dvba)                     \
0217     LTC3676_REG(_id, _name, linear,                                \
0218             LTC3676_ ## _en, 7,                                \
0219             LTC3676_ ## _dvba, 0x1f)
0220
0221 #define LTC3676_FIXED_REG(_id, _name, _en_reg, _en_bit)                \
0222     LTC3676_REG(_id, _name, fixed, LTC3676_ ## _en_reg, _en_bit, 0, 0)
0223
0224 static const struct regulator_desc ltc3676_regulators[LTC3676_NUM_REGULATORS] = {
0225     LTC3676_LINEAR_REG(SW1, sw1, BUCK1, DVB1A),
0226     LTC3676_LINEAR_REG(SW2, sw2, BUCK2, DVB2A),
0227     LTC3676_LINEAR_REG(SW3, sw3, BUCK3, DVB3A),
0228     LTC3676_LINEAR_REG(SW4, sw4, BUCK4, DVB4A),
0229     LTC3676_REG(LDO1, ldo1, fixed_standby, 0, 0, 0, 0),
0230     LTC3676_FIXED_REG(LDO2, ldo2, LDOA, 2),
0231     LTC3676_FIXED_REG(LDO3, ldo3, LDOA, 5),
0232     LTC3676_FIXED_REG(LDO4, ldo4, LDOB, 2),
0233 };
0234
0235 static bool ltc3676_readable_writeable_reg(struct device *dev, unsigned int reg)
0236 {
0237     switch (reg) {
0238     case LTC3676_BUCK1 ... LTC3676_IRQSTAT:
0239     case LTC3676_HRST:
0240     case LTC3676_CLIRQ:
0241         return true;
0242     }
0243     return false;
0244 }
0245
0246 static bool ltc3676_volatile_reg(struct device *dev, unsigned int reg)
0247 {
0248     switch (reg) {
0249     case LTC3676_IRQSTAT ... LTC3676_PGSTATRT:
0250         return true;
0251     }
0252     return false;
0253 }
0254
0255 static const struct regmap_config ltc3676_regmap_config = {
0256     .reg_bits = 8,
0257     .val_bits = 8,
0258     .writeable_reg = ltc3676_readable_writeable_reg,
0259     .readable_reg = ltc3676_readable_writeable_reg,
0260     .volatile_reg = ltc3676_volatile_reg,
0261     .max_register = LTC3676_CLIRQ,
0262     .use_single_read = true,
0263     .use_single_write = true,
0264     .cache_type = REGCACHE_RBTREE,
0265 };
0266
0267 static irqreturn_t ltc3676_isr(int irq, void *dev_id)
0268 {
0269     struct ltc3676 *ltc3676 = dev_id;
0270     struct device *dev = ltc3676->dev;
0271     unsigned int i, irqstat, event;
0272
0273     regmap_read(ltc3676->regmap, LTC3676_IRQSTAT, &irqstat);
0274
0275     dev_dbg(dev, "irq%d irqstat=0x%02x\n", irq, irqstat);
0276     if (irqstat & LTC3676_IRQSTAT_THERMAL_WARN) {
0277         dev_warn(dev, "Over-temperature Warning\n");
0278         event = REGULATOR_EVENT_OVER_TEMP;
0279         for (i = 0; i < LTC3676_NUM_REGULATORS; i++)
0280             regulator_notifier_call_chain(ltc3676->regulators[i],
0281                               event, NULL);
0282     }
0283
0284     if (irqstat & LTC3676_IRQSTAT_UNDERVOLT_WARN) {
0285         dev_info(dev, "Undervoltage Warning\n");
0286         event = REGULATOR_EVENT_UNDER_VOLTAGE;
0287         for (i = 0; i < LTC3676_NUM_REGULATORS; i++)
0288             regulator_notifier_call_chain(ltc3676->regulators[i],
0289                               event, NULL);
0290     }
0291
0292     /* Clear warning condition */
0293     regmap_write(ltc3676->regmap, LTC3676_CLIRQ, 0);
0294
0295     return IRQ_HANDLED;
0296 }
0297
0298 static int ltc3676_regulator_probe(struct i2c_client *client)
0299 {
0300     struct device *dev = &client->dev;
0301     struct regulator_init_data *init_data = dev_get_platdata(dev);
0302     struct regulator_desc *descs;
0303     struct ltc3676 *ltc3676;
0304     int i, ret;
0305
0306     ltc3676 = devm_kzalloc(dev, sizeof(*ltc3676), GFP_KERNEL);
0307     if (!ltc3676)
0308         return -ENOMEM;
0309
0310     i2c_set_clientdata(client, ltc3676);
0311     ltc3676->dev = dev;
0312
0313     descs = ltc3676->regulator_descs;
0314     memcpy(descs, ltc3676_regulators, sizeof(ltc3676_regulators));
0315     descs[LTC3676_LDO3].fixed_uV = 1800000; /* LDO3 is fixed 1.8V */
0316
0317     ltc3676->regmap = devm_regmap_init_i2c(client, &ltc3676_regmap_config);
0318     if (IS_ERR(ltc3676->regmap)) {
0319         ret = PTR_ERR(ltc3676->regmap);
0320         dev_err(dev, "failed to initialize regmap: %d\n", ret);
0321         return ret;
0322     }
0323
0324     for (i = 0; i < LTC3676_NUM_REGULATORS; i++) {
0325         struct regulator_desc *desc = &ltc3676->regulator_descs[i];
0326         struct regulator_config config = { };
0327
0328         if (init_data)
0329             config.init_data = &init_data[i];
0330
0331         config.dev = dev;
0332         config.driver_data = ltc3676;
0333
0334         ltc3676->regulators[i] = devm_regulator_register(dev, desc,
0335                                  &config);
0336         if (IS_ERR(ltc3676->regulators[i])) {
0337             ret = PTR_ERR(ltc3676->regulators[i]);
0338             dev_err(dev, "failed to register regulator %s: %d\n",
0339                 desc->name, ret);
0340             return ret;
0341         }
0342     }
0343
0344     regmap_write(ltc3676->regmap, LTC3676_CLIRQ, 0);
0345     if (client->irq) {
0346         ret = devm_request_threaded_irq(dev, client->irq, NULL,
0347                         ltc3676_isr,
0348                         IRQF_TRIGGER_LOW | IRQF_ONESHOT,
0349                         client->name, ltc3676);
0350         if (ret) {
0351             dev_err(dev, "Failed to request IRQ: %d\n", ret);
0352             return ret;
0353         }
0354     }
0355
0356     return 0;
0357 }
0358
0359 static const struct i2c_device_id ltc3676_i2c_id[] = {
0360     { "ltc3676" },
0361     { }
0362 };
0363 MODULE_DEVICE_TABLE(i2c, ltc3676_i2c_id);
0364
0365 static const struct of_device_id __maybe_unused ltc3676_of_match[] = {
0366     { .compatible = "lltc,ltc3676" },
0367     { },
0368 };
0369 MODULE_DEVICE_TABLE(of, ltc3676_of_match);
0370
0371 static struct i2c_driver ltc3676_driver = {
0372     .driver = {
0373         .name = DRIVER_NAME,
0374         .of_match_table = of_match_ptr(ltc3676_of_match),
0375     },
0376     .probe_new = ltc3676_regulator_probe,
0377     .id_table = ltc3676_i2c_id,
0378 };
0379 module_i2c_driver(ltc3676_driver);
0380
0381 MODULE_AUTHOR("Tim Harvey <tharvey@gateworks.com>");
0382 MODULE_DESCRIPTION("Regulator driver for Linear Technology LTC3676");
0383 MODULE_LICENSE("GPL v2");