diff options
Diffstat (limited to 'drivers/regulator/max5970-regulator.c')
| -rw-r--r-- | drivers/regulator/max5970-regulator.c | 642 |
1 files changed, 642 insertions, 0 deletions
diff --git a/drivers/regulator/max5970-regulator.c b/drivers/regulator/max5970-regulator.c new file mode 100644 index 000000000000..fc14177ddf5d --- /dev/null +++ b/drivers/regulator/max5970-regulator.c @@ -0,0 +1,642 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Device driver for regulators in MAX5970 and MAX5978 IC + * + * Copyright (c) 2022 9elements GmbH + * + * Author: Patrick Rudolph <patrick.rudolph@9elements.com> + */ + +#include <linux/bitops.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/hwmon.h> +#include <linux/module.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/i2c.h> +#include <linux/regmap.h> +#include <linux/regulator/driver.h> +#include <linux/regulator/machine.h> +#include <linux/regulator/of_regulator.h> +#include <linux/platform_device.h> + +#include <linux/mfd/max5970.h> + +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 <patrick.rudolph@9elements.com>"); +MODULE_DESCRIPTION("MAX5970_hot-swap controller driver"); +MODULE_LICENSE("GPL v2"); |