515 lines
13 KiB
C
515 lines
13 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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* Device driver for regulators in MAX5970 and MAX5978 IC
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*
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* Copyright (c) 2022 9elements GmbH
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*
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* Author: Patrick Rudolph <patrick.rudolph@9elements.com>
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*/
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#include <linux/bitops.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/module.h>
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#include <linux/io.h>
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#include <linux/of.h>
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#include <linux/i2c.h>
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#include <linux/regmap.h>
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#include <linux/regulator/driver.h>
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#include <linux/regulator/machine.h>
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#include <linux/regulator/of_regulator.h>
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#include <linux/platform_device.h>
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#include <linux/mfd/max5970.h>
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struct max5970_regulator {
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int num_switches, mon_rng, irng, shunt_micro_ohms, lim_uA;
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struct regmap *regmap;
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};
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enum max597x_regulator_id {
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MAX597X_SW0,
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MAX597X_SW1,
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};
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static int max597x_uvp_ovp_check_mode(struct regulator_dev *rdev, int severity)
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{
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int ret, reg;
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/* Status1 register contains the soft strap values sampled at POR */
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ret = regmap_read(rdev->regmap, MAX5970_REG_STATUS1, ®);
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if (ret)
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return ret;
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/* Check soft straps match requested mode */
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if (severity == REGULATOR_SEVERITY_PROT) {
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if (STATUS1_PROT(reg) != STATUS1_PROT_SHUTDOWN)
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return -EOPNOTSUPP;
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return 0;
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}
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if (STATUS1_PROT(reg) == STATUS1_PROT_SHUTDOWN)
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return -EOPNOTSUPP;
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return 0;
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}
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static int max597x_set_vp(struct regulator_dev *rdev, int lim_uV, int severity,
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bool enable, bool overvoltage)
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{
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int off_h, off_l, reg, ret;
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struct max5970_regulator *data = rdev_get_drvdata(rdev);
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int channel = rdev_get_id(rdev);
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if (overvoltage) {
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if (severity == REGULATOR_SEVERITY_WARN) {
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off_h = MAX5970_REG_CH_OV_WARN_H(channel);
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off_l = MAX5970_REG_CH_OV_WARN_L(channel);
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} else {
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off_h = MAX5970_REG_CH_OV_CRIT_H(channel);
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off_l = MAX5970_REG_CH_OV_CRIT_L(channel);
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}
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} else {
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if (severity == REGULATOR_SEVERITY_WARN) {
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off_h = MAX5970_REG_CH_UV_WARN_H(channel);
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off_l = MAX5970_REG_CH_UV_WARN_L(channel);
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} else {
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off_h = MAX5970_REG_CH_UV_CRIT_H(channel);
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off_l = MAX5970_REG_CH_UV_CRIT_L(channel);
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}
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}
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if (enable)
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/* reg = ADC_MASK * (lim_uV / 1000000) / (data->mon_rng / 1000000) */
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reg = ADC_MASK * lim_uV / data->mon_rng;
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else
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reg = 0;
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ret = regmap_write(rdev->regmap, off_h, MAX5970_VAL2REG_H(reg));
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if (ret)
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return ret;
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ret = regmap_write(rdev->regmap, off_l, MAX5970_VAL2REG_L(reg));
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if (ret)
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return ret;
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return 0;
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}
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static int max597x_set_uvp(struct regulator_dev *rdev, int lim_uV, int severity,
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bool enable)
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{
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int ret;
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/*
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* MAX5970 has enable control as a special value in limit reg. Can't
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* set limit but keep feature disabled or enable W/O given limit.
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*/
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if ((lim_uV && !enable) || (!lim_uV && enable))
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return -EINVAL;
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ret = max597x_uvp_ovp_check_mode(rdev, severity);
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if (ret)
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return ret;
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return max597x_set_vp(rdev, lim_uV, severity, enable, false);
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}
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static int max597x_set_ovp(struct regulator_dev *rdev, int lim_uV, int severity,
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bool enable)
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{
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int ret;
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/*
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* MAX5970 has enable control as a special value in limit reg. Can't
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* set limit but keep feature disabled or enable W/O given limit.
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*/
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if ((lim_uV && !enable) || (!lim_uV && enable))
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return -EINVAL;
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ret = max597x_uvp_ovp_check_mode(rdev, severity);
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if (ret)
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return ret;
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return max597x_set_vp(rdev, lim_uV, severity, enable, true);
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}
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static int max597x_set_ocp(struct regulator_dev *rdev, int lim_uA,
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int severity, bool enable)
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{
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int val, reg;
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unsigned int vthst, vthfst;
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struct max5970_regulator *data = rdev_get_drvdata(rdev);
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int rdev_id = rdev_get_id(rdev);
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/*
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* MAX5970 doesn't has enable control for ocp.
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* If limit is specified but enable is not set then hold the value in
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* variable & later use it when ocp needs to be enabled.
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*/
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if (lim_uA != 0 && lim_uA != data->lim_uA)
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data->lim_uA = lim_uA;
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if (severity != REGULATOR_SEVERITY_PROT)
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return -EINVAL;
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if (enable) {
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/* Calc Vtrip threshold in uV. */
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vthst =
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div_u64(mul_u32_u32(data->shunt_micro_ohms, data->lim_uA),
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1000000);
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/*
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* As recommended in datasheed, add 20% margin to avoid
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* spurious event & passive component tolerance.
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*/
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vthst = div_u64(mul_u32_u32(vthst, 120), 100);
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/* Calc fast Vtrip threshold in uV */
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vthfst = vthst * (MAX5970_FAST2SLOW_RATIO / 100);
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if (vthfst > data->irng) {
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dev_err(&rdev->dev, "Current limit out of range\n");
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return -EINVAL;
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}
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/* Fast trip threshold to be programmed */
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val = div_u64(mul_u32_u32(0xFF, vthfst), data->irng);
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} else
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/*
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* Since there is no option to disable ocp, set limit to max
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* value
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*/
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val = 0xFF;
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reg = MAX5970_REG_DAC_FAST(rdev_id);
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return regmap_write(rdev->regmap, reg, val);
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}
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static int max597x_get_status(struct regulator_dev *rdev)
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{
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int val, ret;
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ret = regmap_read(rdev->regmap, MAX5970_REG_STATUS3, &val);
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if (ret)
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return ret;
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if (val & MAX5970_STATUS3_ALERT)
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return REGULATOR_STATUS_ERROR;
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ret = regulator_is_enabled_regmap(rdev);
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if (ret < 0)
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return ret;
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if (ret)
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return REGULATOR_STATUS_ON;
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return REGULATOR_STATUS_OFF;
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}
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static const struct regulator_ops max597x_switch_ops = {
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.enable = regulator_enable_regmap,
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.disable = regulator_disable_regmap,
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.is_enabled = regulator_is_enabled_regmap,
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.get_status = max597x_get_status,
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.set_over_voltage_protection = max597x_set_ovp,
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.set_under_voltage_protection = max597x_set_uvp,
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.set_over_current_protection = max597x_set_ocp,
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};
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static int max597x_dt_parse(struct device_node *np,
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const struct regulator_desc *desc,
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struct regulator_config *cfg)
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{
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struct max5970_regulator *data = cfg->driver_data;
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int ret = 0;
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ret =
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of_property_read_u32(np, "shunt-resistor-micro-ohms",
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&data->shunt_micro_ohms);
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if (ret < 0)
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dev_err(cfg->dev,
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"property 'shunt-resistor-micro-ohms' not found, err %d\n",
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ret);
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return ret;
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}
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#define MAX597X_SWITCH(_ID, _ereg, _chan, _supply) { \
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.name = #_ID, \
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.of_match = of_match_ptr(#_ID), \
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.ops = &max597x_switch_ops, \
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.regulators_node = of_match_ptr("regulators"), \
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.type = REGULATOR_VOLTAGE, \
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.id = MAX597X_##_ID, \
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.owner = THIS_MODULE, \
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.supply_name = _supply, \
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.enable_reg = _ereg, \
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.enable_mask = CHXEN((_chan)), \
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.of_parse_cb = max597x_dt_parse, \
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}
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static const struct regulator_desc regulators[] = {
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MAX597X_SWITCH(SW0, MAX5970_REG_CHXEN, 0, "vss1"),
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MAX597X_SWITCH(SW1, MAX5970_REG_CHXEN, 1, "vss2"),
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};
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static int max597x_regmap_read_clear(struct regmap *map, unsigned int reg,
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unsigned int *val)
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{
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int ret;
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ret = regmap_read(map, reg, val);
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if (ret)
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return ret;
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if (*val)
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return regmap_write(map, reg, *val);
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return 0;
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}
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static int max597x_irq_handler(int irq, struct regulator_irq_data *rid,
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unsigned long *dev_mask)
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{
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struct regulator_err_state *stat;
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struct max5970_regulator *d = (struct max5970_regulator *)rid->data;
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int val, ret, i;
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ret = max597x_regmap_read_clear(d->regmap, MAX5970_REG_FAULT0, &val);
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if (ret)
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return REGULATOR_FAILED_RETRY;
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*dev_mask = 0;
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for (i = 0; i < d->num_switches; i++) {
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stat = &rid->states[i];
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stat->notifs = 0;
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stat->errors = 0;
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}
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for (i = 0; i < d->num_switches; i++) {
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stat = &rid->states[i];
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if (val & UV_STATUS_CRIT(i)) {
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*dev_mask |= 1 << i;
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stat->notifs |= REGULATOR_EVENT_UNDER_VOLTAGE;
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stat->errors |= REGULATOR_ERROR_UNDER_VOLTAGE;
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} else if (val & UV_STATUS_WARN(i)) {
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*dev_mask |= 1 << i;
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stat->notifs |= REGULATOR_EVENT_UNDER_VOLTAGE_WARN;
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stat->errors |= REGULATOR_ERROR_UNDER_VOLTAGE_WARN;
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}
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}
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ret = max597x_regmap_read_clear(d->regmap, MAX5970_REG_FAULT1, &val);
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if (ret)
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return REGULATOR_FAILED_RETRY;
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for (i = 0; i < d->num_switches; i++) {
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stat = &rid->states[i];
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if (val & OV_STATUS_CRIT(i)) {
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*dev_mask |= 1 << i;
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stat->notifs |= REGULATOR_EVENT_REGULATION_OUT;
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stat->errors |= REGULATOR_ERROR_REGULATION_OUT;
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} else if (val & OV_STATUS_WARN(i)) {
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*dev_mask |= 1 << i;
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stat->notifs |= REGULATOR_EVENT_OVER_VOLTAGE_WARN;
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stat->errors |= REGULATOR_ERROR_OVER_VOLTAGE_WARN;
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}
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}
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ret = max597x_regmap_read_clear(d->regmap, MAX5970_REG_FAULT2, &val);
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if (ret)
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return REGULATOR_FAILED_RETRY;
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for (i = 0; i < d->num_switches; i++) {
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stat = &rid->states[i];
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if (val & OC_STATUS_WARN(i)) {
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*dev_mask |= 1 << i;
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stat->notifs |= REGULATOR_EVENT_OVER_CURRENT_WARN;
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stat->errors |= REGULATOR_ERROR_OVER_CURRENT_WARN;
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}
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}
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ret = regmap_read(d->regmap, MAX5970_REG_STATUS0, &val);
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if (ret)
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return REGULATOR_FAILED_RETRY;
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for (i = 0; i < d->num_switches; i++) {
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stat = &rid->states[i];
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if ((val & MAX5970_CB_IFAULTF(i))
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|| (val & MAX5970_CB_IFAULTS(i))) {
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*dev_mask |= 1 << i;
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stat->notifs |=
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REGULATOR_EVENT_OVER_CURRENT |
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REGULATOR_EVENT_DISABLE;
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stat->errors |=
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REGULATOR_ERROR_OVER_CURRENT | REGULATOR_ERROR_FAIL;
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/* Clear the sub-IRQ status */
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regulator_disable_regmap(stat->rdev);
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}
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}
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return 0;
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}
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static int max597x_adc_range(struct regmap *regmap, const int ch,
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u32 *irng, u32 *mon_rng)
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{
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unsigned int reg;
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int ret;
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/* Decode current ADC range */
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ret = regmap_read(regmap, MAX5970_REG_STATUS2, ®);
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if (ret)
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return ret;
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switch (MAX5970_IRNG(reg, ch)) {
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case 0:
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*irng = 100000; /* 100 mV */
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break;
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case 1:
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*irng = 50000; /* 50 mV */
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break;
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case 2:
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*irng = 25000; /* 25 mV */
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break;
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default:
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return -EINVAL;
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}
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/* Decode current voltage monitor range */
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ret = regmap_read(regmap, MAX5970_REG_MON_RANGE, ®);
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if (ret)
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return ret;
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*mon_rng = MAX5970_MON_MAX_RANGE_UV >> MAX5970_MON(reg, ch);
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return 0;
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}
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static int max597x_setup_irq(struct device *dev,
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int irq,
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struct regulator_dev *rdevs[MAX5970_NUM_SWITCHES],
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int num_switches, struct max5970_regulator *data)
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{
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struct regulator_irq_desc max597x_notif = {
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.name = "max597x-irq",
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.map_event = max597x_irq_handler,
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.data = data,
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};
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int errs = REGULATOR_ERROR_UNDER_VOLTAGE |
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REGULATOR_ERROR_UNDER_VOLTAGE_WARN |
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REGULATOR_ERROR_OVER_VOLTAGE_WARN |
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REGULATOR_ERROR_REGULATION_OUT |
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REGULATOR_ERROR_OVER_CURRENT |
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REGULATOR_ERROR_OVER_CURRENT_WARN | REGULATOR_ERROR_FAIL;
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void *irq_helper;
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/* Register notifiers - can fail if IRQ is not given */
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irq_helper = devm_regulator_irq_helper(dev, &max597x_notif,
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irq, 0, errs, NULL,
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&rdevs[0], num_switches);
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if (IS_ERR(irq_helper)) {
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if (PTR_ERR(irq_helper) == -EPROBE_DEFER)
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return -EPROBE_DEFER;
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dev_warn(dev, "IRQ disabled %pe\n", irq_helper);
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}
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return 0;
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}
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static int max597x_regulator_probe(struct platform_device *pdev)
|
||
|
{
|
||
|
struct max5970_data *max597x;
|
||
|
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[MAX5970_NUM_SWITCHES];
|
||
|
int num_switches;
|
||
|
int ret, i;
|
||
|
|
||
|
if (!regmap)
|
||
|
return -EPROBE_DEFER;
|
||
|
|
||
|
max597x = devm_kzalloc(&i2c->dev, sizeof(struct max5970_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 = MAX5978_NUM_SWITCHES;
|
||
|
else if (of_device_is_compatible(i2c->dev.of_node, "maxim,max5970"))
|
||
|
max597x->num_switches = MAX5970_NUM_SWITCHES;
|
||
|
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 max5970_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,
|
||
|
®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;
|
||
|
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 = "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");
|