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kernel/drivers/regulator/max597x-regulator.c

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// 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/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/max597x.h>
struct max597x_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 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, &reg);
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 max597x_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 max597x_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 max597x_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, *val);
return 0;
}
static int max597x_irq_handler(int irq, struct regulator_irq_data *rid,
unsigned long *dev_mask)
{
struct regulator_err_state *stat;
struct max597x_regulator *d = (struct max597x_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,
u32 *irng, u32 *mon_rng)
{
unsigned int reg;
int ret;
/* Decode current ADC range */
ret = regmap_read(regmap, MAX5970_REG_STATUS2, &reg);
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, &reg);
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 max597x_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 max597x_data *max597x;
struct regmap *regmap = dev_get_regmap(pdev->dev.parent, NULL);
struct max597x_regulator *data;
struct i2c_client *i2c = to_i2c_client(pdev->dev.parent);
struct regulator_config config = { };
struct regulator_dev *rdev;
struct regulator_dev *rdevs[MAX5970_NUM_SWITCHES];
int num_switches;
int ret, i;
if (!regmap)
return -EPROBE_DEFER;
max597x = devm_kzalloc(&i2c->dev, sizeof(struct max597x_data), GFP_KERNEL);
if (!max597x)
return -ENOMEM;
i2c_set_clientdata(i2c, max597x);
if (of_device_is_compatible(i2c->dev.of_node, "maxim,max5978"))
max597x->num_switches = MAX597x_TYPE_MAX5978;
else if (of_device_is_compatible(i2c->dev.of_node, "maxim,max5970"))
max597x->num_switches = MAX597x_TYPE_MAX5970;
else
return -ENODEV;
i2c_set_clientdata(i2c, max597x);
num_switches = max597x->num_switches;
for (i = 0; i < num_switches; i++) {
data =
devm_kzalloc(&i2c->dev, sizeof(struct max597x_regulator),
GFP_KERNEL);
if (!data)
return -ENOMEM;
data->num_switches = num_switches;
data->regmap = regmap;
ret = max597x_adc_range(regmap, i, &max597x->irng[i], &max597x->mon_rng[i]);
if (ret < 0)
return ret;
data->irng = max597x->irng[i];
data->mon_rng = max597x->mon_rng[i];
config.dev = &i2c->dev;
config.driver_data = (void *)data;
config.regmap = data->regmap;
rdev = devm_regulator_register(&i2c->dev,
&regulators[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;
max597x->shunt_micro_ohms[i] = data->shunt_micro_ohms;
}
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 = "max597x-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");
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