--- /dev/null
+// 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/version.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, ®);
+ 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 ret, 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);
+ ret = regmap_write(rdev->regmap, reg, val);
+
+ return ret;
+}
+
+static int max597x_get_status(struct regulator_dev *rdev)
+{
+ int val, ret;
+
+ ret = regmap_read(rdev->regmap, MAX5970_REG_STATUS3, &val);
+ if (ret)
+ return REGULATOR_FAILED_RETRY;
+
+ 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 const struct regmap_config max597x_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = MAX_REGISTERS,
+};
+
+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, ®);
+ 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 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 = dev_get_drvdata(pdev->dev.parent);
+ struct max597x_regulator *data;
+
+ struct regulator_config config = { };
+ struct regulator_dev *rdev;
+ struct regulator_dev *rdevs[MAX5970_NUM_SWITCHES];
+ int num_switches = max597x->num_switches;
+ int ret, i;
+
+ for (i = 0; i < num_switches; i++) {
+ data =
+ devm_kzalloc(max597x->dev, sizeof(struct max597x_regulator),
+ GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->num_switches = num_switches;
+ data->regmap = max597x->regmap;
+
+ if (ret < 0)
+ return ret;
+
+ ret = max597x_adc_range(data->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 = max597x->dev;
+ config.driver_data = (void *)data;
+ config.regmap = data->regmap;
+ rdev = devm_regulator_register(max597x->dev,
+ ®ulators[i], &config);
+ if (IS_ERR(rdev)) {
+ dev_err(max597x->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 (max597x->irq) {
+ ret =
+ max597x_setup_irq(max597x->dev, max597x->irq, rdevs, num_switches,
+ data);
+ if (ret) {
+ dev_err(max597x->dev, "IRQ setup failed");
+ return ret;
+ }
+ }
+
+ return ret;
+}
+
+static struct platform_driver max597x_regulator_driver = {
+ .driver = {
+ .name = "max597x-regulator",
+ },
+ .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");
projects / platform / kernel / linux-starfive.git / commitdiff