// SPDX-License-Identifier: GPL-2.0 /* * Device driver for regulators in MAX5970 and MAX5978 IC * * Copyright (c) 2022 9elements GmbH * * Author: Patrick Rudolph */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include struct max5970_regulator { int num_switches, mon_rng, irng, shunt_micro_ohms, lim_uA; struct regmap *regmap; }; enum max597x_regulator_id { MAX597X_sw0, MAX597X_sw1, }; static int max5970_read_adc(struct regmap *regmap, int reg, long *val) { u8 reg_data[2]; int ret; ret = regmap_bulk_read(regmap, reg, ®_data[0], 2); if (ret < 0) return ret; *val = (reg_data[0] << 2) | (reg_data[1] & 3); return 0; } static int max5970_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *val) { struct regulator_dev **rdevs = dev_get_drvdata(dev); struct max5970_regulator *ddata = rdev_get_drvdata(rdevs[channel]); struct regmap *regmap = ddata->regmap; int ret; switch (type) { case hwmon_curr: switch (attr) { case hwmon_curr_input: ret = max5970_read_adc(regmap, MAX5970_REG_CURRENT_H(channel), val); if (ret < 0) return ret; /* * Calculate current from ADC value, IRNG range & shunt resistor value. * ddata->irng holds the voltage corresponding to the maximum value the * 10-bit ADC can measure. * To obtain the output, multiply the ADC value by the IRNG range (in * millivolts) and then divide it by the maximum value of the 10-bit ADC. */ *val = (*val * ddata->irng) >> 10; /* Convert the voltage measurement across shunt resistor to current */ *val = (*val * 1000) / ddata->shunt_micro_ohms; return 0; default: return -EOPNOTSUPP; } case hwmon_in: switch (attr) { case hwmon_in_input: ret = max5970_read_adc(regmap, MAX5970_REG_VOLTAGE_H(channel), val); if (ret < 0) return ret; /* * Calculate voltage from ADC value and MON range. * ddata->mon_rng holds the voltage corresponding to the maximum value the * 10-bit ADC can measure. * To obtain the output, multiply the ADC value by the MON range (in * microvolts) and then divide it by the maximum value of the 10-bit ADC. */ *val = mul_u64_u32_shr(*val, ddata->mon_rng, 10); /* uV to mV */ *val = *val / 1000; return 0; default: return -EOPNOTSUPP; } default: return -EOPNOTSUPP; } } static umode_t max5970_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, int channel) { struct regulator_dev **rdevs = (struct regulator_dev **)data; struct max5970_regulator *ddata; if (channel >= MAX5970_NUM_SWITCHES || !rdevs[channel]) return 0; ddata = rdev_get_drvdata(rdevs[channel]); if (channel >= ddata->num_switches) return 0; switch (type) { case hwmon_in: switch (attr) { case hwmon_in_input: return 0444; default: break; } break; case hwmon_curr: switch (attr) { case hwmon_curr_input: /* Current measurement requires knowledge of the shunt resistor value. */ if (ddata->shunt_micro_ohms) return 0444; break; default: break; } break; default: break; } return 0; } static const struct hwmon_ops max5970_hwmon_ops = { .is_visible = max5970_is_visible, .read = max5970_read, }; static const struct hwmon_channel_info *max5970_info[] = { HWMON_CHANNEL_INFO(in, HWMON_I_INPUT, HWMON_I_INPUT), HWMON_CHANNEL_INFO(curr, HWMON_C_INPUT, HWMON_C_INPUT), NULL }; static const struct hwmon_chip_info max5970_chip_info = { .ops = &max5970_hwmon_ops, .info = max5970_info, }; static int max597x_uvp_ovp_check_mode(struct regulator_dev *rdev, int severity) { int ret, reg; /* Status1 register contains the soft strap values sampled at POR */ ret = regmap_read(rdev->regmap, MAX5970_REG_STATUS1, ®); if (ret) return ret; /* Check soft straps match requested mode */ if (severity == REGULATOR_SEVERITY_PROT) { if (STATUS1_PROT(reg) != STATUS1_PROT_SHUTDOWN) return -EOPNOTSUPP; return 0; } if (STATUS1_PROT(reg) == STATUS1_PROT_SHUTDOWN) return -EOPNOTSUPP; return 0; } static int max597x_set_vp(struct regulator_dev *rdev, int lim_uV, int severity, bool enable, bool overvoltage) { int off_h, off_l, reg, ret; struct max5970_regulator *data = rdev_get_drvdata(rdev); int channel = rdev_get_id(rdev); if (overvoltage) { if (severity == REGULATOR_SEVERITY_WARN) { off_h = MAX5970_REG_CH_OV_WARN_H(channel); off_l = MAX5970_REG_CH_OV_WARN_L(channel); } else { off_h = MAX5970_REG_CH_OV_CRIT_H(channel); off_l = MAX5970_REG_CH_OV_CRIT_L(channel); } } else { if (severity == REGULATOR_SEVERITY_WARN) { off_h = MAX5970_REG_CH_UV_WARN_H(channel); off_l = MAX5970_REG_CH_UV_WARN_L(channel); } else { off_h = MAX5970_REG_CH_UV_CRIT_H(channel); off_l = MAX5970_REG_CH_UV_CRIT_L(channel); } } if (enable) /* reg = ADC_MASK * (lim_uV / 1000000) / (data->mon_rng / 1000000) */ reg = ADC_MASK * lim_uV / data->mon_rng; else reg = 0; ret = regmap_write(rdev->regmap, off_h, MAX5970_VAL2REG_H(reg)); if (ret) return ret; ret = regmap_write(rdev->regmap, off_l, MAX5970_VAL2REG_L(reg)); if (ret) return ret; return 0; } static int max597x_set_uvp(struct regulator_dev *rdev, int lim_uV, int severity, bool enable) { int ret; /* * MAX5970 has enable control as a special value in limit reg. Can't * set limit but keep feature disabled or enable W/O given limit. */ if ((lim_uV && !enable) || (!lim_uV && enable)) return -EINVAL; ret = max597x_uvp_ovp_check_mode(rdev, severity); if (ret) return ret; return max597x_set_vp(rdev, lim_uV, severity, enable, false); } static int max597x_set_ovp(struct regulator_dev *rdev, int lim_uV, int severity, bool enable) { int ret; /* * MAX5970 has enable control as a special value in limit reg. Can't * set limit but keep feature disabled or enable W/O given limit. */ if ((lim_uV && !enable) || (!lim_uV && enable)) return -EINVAL; ret = max597x_uvp_ovp_check_mode(rdev, severity); if (ret) return ret; return max597x_set_vp(rdev, lim_uV, severity, enable, true); } static int max597x_set_ocp(struct regulator_dev *rdev, int lim_uA, int severity, bool enable) { int val, reg; unsigned int vthst, vthfst; struct max5970_regulator *data = rdev_get_drvdata(rdev); int rdev_id = rdev_get_id(rdev); /* * MAX5970 doesn't has enable control for ocp. * If limit is specified but enable is not set then hold the value in * variable & later use it when ocp needs to be enabled. */ if (lim_uA != 0 && lim_uA != data->lim_uA) data->lim_uA = lim_uA; if (severity != REGULATOR_SEVERITY_PROT) return -EINVAL; if (enable) { /* Calc Vtrip threshold in uV. */ vthst = div_u64(mul_u32_u32(data->shunt_micro_ohms, data->lim_uA), 1000000); /* * As recommended in datasheed, add 20% margin to avoid * spurious event & passive component tolerance. */ vthst = div_u64(mul_u32_u32(vthst, 120), 100); /* Calc fast Vtrip threshold in uV */ vthfst = vthst * (MAX5970_FAST2SLOW_RATIO / 100); if (vthfst > data->irng) { dev_err(&rdev->dev, "Current limit out of range\n"); return -EINVAL; } /* Fast trip threshold to be programmed */ val = div_u64(mul_u32_u32(0xFF, vthfst), data->irng); } else /* * Since there is no option to disable ocp, set limit to max * value */ val = 0xFF; reg = MAX5970_REG_DAC_FAST(rdev_id); return regmap_write(rdev->regmap, reg, val); } static int max597x_get_status(struct regulator_dev *rdev) { int val, ret; ret = regmap_read(rdev->regmap, MAX5970_REG_STATUS3, &val); if (ret) return ret; if (val & MAX5970_STATUS3_ALERT) return REGULATOR_STATUS_ERROR; ret = regulator_is_enabled_regmap(rdev); if (ret < 0) return ret; if (ret) return REGULATOR_STATUS_ON; return REGULATOR_STATUS_OFF; } static const struct regulator_ops max597x_switch_ops = { .enable = regulator_enable_regmap, .disable = regulator_disable_regmap, .is_enabled = regulator_is_enabled_regmap, .get_status = max597x_get_status, .set_over_voltage_protection = max597x_set_ovp, .set_under_voltage_protection = max597x_set_uvp, .set_over_current_protection = max597x_set_ocp, }; static int max597x_dt_parse(struct device_node *np, const struct regulator_desc *desc, struct regulator_config *cfg) { struct max5970_regulator *data = cfg->driver_data; int ret = 0; ret = of_property_read_u32(np, "shunt-resistor-micro-ohms", &data->shunt_micro_ohms); if (ret < 0) dev_err(cfg->dev, "property 'shunt-resistor-micro-ohms' not found, err %d\n", ret); return ret; } #define MAX597X_SWITCH(_ID, _ereg, _chan, _supply) { \ .name = #_ID, \ .of_match = of_match_ptr(#_ID), \ .ops = &max597x_switch_ops, \ .regulators_node = of_match_ptr("regulators"), \ .type = REGULATOR_VOLTAGE, \ .id = MAX597X_##_ID, \ .owner = THIS_MODULE, \ .supply_name = _supply, \ .enable_reg = _ereg, \ .enable_mask = CHXEN((_chan)), \ .of_parse_cb = max597x_dt_parse, \ } static const struct regulator_desc regulators[] = { MAX597X_SWITCH(sw0, MAX5970_REG_CHXEN, 0, "vss1"), MAX597X_SWITCH(sw1, MAX5970_REG_CHXEN, 1, "vss2"), }; static int max597x_regmap_read_clear(struct regmap *map, unsigned int reg, unsigned int *val) { int ret; ret = regmap_read(map, reg, val); if (ret) return ret; if (*val) return regmap_write(map, reg, 0); return 0; } static int max597x_irq_handler(int irq, struct regulator_irq_data *rid, unsigned long *dev_mask) { struct regulator_err_state *stat; struct max5970_regulator *d = (struct max5970_regulator *)rid->data; int val, ret, i; ret = max597x_regmap_read_clear(d->regmap, MAX5970_REG_FAULT0, &val); if (ret) return REGULATOR_FAILED_RETRY; *dev_mask = 0; for (i = 0; i < d->num_switches; i++) { stat = &rid->states[i]; stat->notifs = 0; stat->errors = 0; } for (i = 0; i < d->num_switches; i++) { stat = &rid->states[i]; if (val & UV_STATUS_CRIT(i)) { *dev_mask |= 1 << i; stat->notifs |= REGULATOR_EVENT_UNDER_VOLTAGE; stat->errors |= REGULATOR_ERROR_UNDER_VOLTAGE; } else if (val & UV_STATUS_WARN(i)) { *dev_mask |= 1 << i; stat->notifs |= REGULATOR_EVENT_UNDER_VOLTAGE_WARN; stat->errors |= REGULATOR_ERROR_UNDER_VOLTAGE_WARN; } } ret = max597x_regmap_read_clear(d->regmap, MAX5970_REG_FAULT1, &val); if (ret) return REGULATOR_FAILED_RETRY; for (i = 0; i < d->num_switches; i++) { stat = &rid->states[i]; if (val & OV_STATUS_CRIT(i)) { *dev_mask |= 1 << i; stat->notifs |= REGULATOR_EVENT_REGULATION_OUT; stat->errors |= REGULATOR_ERROR_REGULATION_OUT; } else if (val & OV_STATUS_WARN(i)) { *dev_mask |= 1 << i; stat->notifs |= REGULATOR_EVENT_OVER_VOLTAGE_WARN; stat->errors |= REGULATOR_ERROR_OVER_VOLTAGE_WARN; } } ret = max597x_regmap_read_clear(d->regmap, MAX5970_REG_FAULT2, &val); if (ret) return REGULATOR_FAILED_RETRY; for (i = 0; i < d->num_switches; i++) { stat = &rid->states[i]; if (val & OC_STATUS_WARN(i)) { *dev_mask |= 1 << i; stat->notifs |= REGULATOR_EVENT_OVER_CURRENT_WARN; stat->errors |= REGULATOR_ERROR_OVER_CURRENT_WARN; } } ret = regmap_read(d->regmap, MAX5970_REG_STATUS0, &val); if (ret) return REGULATOR_FAILED_RETRY; for (i = 0; i < d->num_switches; i++) { stat = &rid->states[i]; if ((val & MAX5970_CB_IFAULTF(i)) || (val & MAX5970_CB_IFAULTS(i))) { *dev_mask |= 1 << i; stat->notifs |= REGULATOR_EVENT_OVER_CURRENT | REGULATOR_EVENT_DISABLE; stat->errors |= REGULATOR_ERROR_OVER_CURRENT | REGULATOR_ERROR_FAIL; /* Clear the sub-IRQ status */ regulator_disable_regmap(stat->rdev); } } return 0; } static int max597x_adc_range(struct regmap *regmap, const int ch, int *irng, int *mon_rng) { unsigned int reg; int ret; /* Decode current ADC range */ ret = regmap_read(regmap, MAX5970_REG_STATUS2, ®); if (ret) return ret; switch (MAX5970_IRNG(reg, ch)) { case 0: *irng = 100000; /* 100 mV */ break; case 1: *irng = 50000; /* 50 mV */ break; case 2: *irng = 25000; /* 25 mV */ break; default: return -EINVAL; } /* Decode current voltage monitor range */ ret = regmap_read(regmap, MAX5970_REG_MON_RANGE, ®); if (ret) return ret; *mon_rng = MAX5970_MON_MAX_RANGE_UV >> MAX5970_MON(reg, ch); return 0; } static int max597x_setup_irq(struct device *dev, int irq, struct regulator_dev *rdevs[MAX5970_NUM_SWITCHES], int num_switches, struct max5970_regulator *data) { struct regulator_irq_desc max597x_notif = { .name = "max597x-irq", .map_event = max597x_irq_handler, .data = data, }; int errs = REGULATOR_ERROR_UNDER_VOLTAGE | REGULATOR_ERROR_UNDER_VOLTAGE_WARN | REGULATOR_ERROR_OVER_VOLTAGE_WARN | REGULATOR_ERROR_REGULATION_OUT | REGULATOR_ERROR_OVER_CURRENT | REGULATOR_ERROR_OVER_CURRENT_WARN | REGULATOR_ERROR_FAIL; void *irq_helper; /* Register notifiers - can fail if IRQ is not given */ irq_helper = devm_regulator_irq_helper(dev, &max597x_notif, irq, 0, errs, NULL, &rdevs[0], num_switches); if (IS_ERR(irq_helper)) { if (PTR_ERR(irq_helper) == -EPROBE_DEFER) return -EPROBE_DEFER; dev_warn(dev, "IRQ disabled %pe\n", irq_helper); } return 0; } static int max597x_regulator_probe(struct platform_device *pdev) { struct regmap *regmap = dev_get_regmap(pdev->dev.parent, NULL); struct max5970_regulator *data; struct i2c_client *i2c = to_i2c_client(pdev->dev.parent); struct regulator_config config = { }; struct regulator_dev *rdev; struct regulator_dev **rdevs = NULL; struct device *hwmon_dev; int num_switches; int ret, i; if (!regmap) return -EPROBE_DEFER; rdevs = devm_kcalloc(&i2c->dev, MAX5970_NUM_SWITCHES, sizeof(struct regulator_dev *), GFP_KERNEL); if (!rdevs) return -ENOMEM; if (of_device_is_compatible(i2c->dev.of_node, "maxim,max5978")) num_switches = MAX5978_NUM_SWITCHES; else if (of_device_is_compatible(i2c->dev.of_node, "maxim,max5970")) num_switches = MAX5970_NUM_SWITCHES; else return -ENODEV; for (i = 0; i < num_switches; i++) { data = devm_kzalloc(&i2c->dev, sizeof(struct max5970_regulator), GFP_KERNEL); if (!data) return -ENOMEM; data->num_switches = num_switches; data->regmap = regmap; ret = max597x_adc_range(regmap, i, &data->irng, &data->mon_rng); if (ret < 0) return ret; config.dev = &i2c->dev; config.driver_data = (void *)data; config.regmap = data->regmap; rdev = devm_regulator_register(&i2c->dev, ®ulators[i], &config); if (IS_ERR(rdev)) { dev_err(&i2c->dev, "failed to register regulator %s\n", regulators[i].name); return PTR_ERR(rdev); } rdevs[i] = rdev; } if (IS_REACHABLE(CONFIG_HWMON)) { hwmon_dev = devm_hwmon_device_register_with_info(&i2c->dev, "max5970", rdevs, &max5970_chip_info, NULL); if (IS_ERR(hwmon_dev)) { return dev_err_probe(&i2c->dev, PTR_ERR(hwmon_dev), "Unable to register hwmon device\n"); } } if (i2c->irq) { ret = max597x_setup_irq(&i2c->dev, i2c->irq, rdevs, num_switches, data); if (ret) { dev_err(&i2c->dev, "IRQ setup failed"); return ret; } } return ret; } static struct platform_driver max597x_regulator_driver = { .driver = { .name = "max5970-regulator", .probe_type = PROBE_PREFER_ASYNCHRONOUS, }, .probe = max597x_regulator_probe, }; module_platform_driver(max597x_regulator_driver); MODULE_AUTHOR("Patrick Rudolph "); MODULE_DESCRIPTION("MAX5970_hot-swap controller driver"); MODULE_LICENSE("GPL v2");