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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (c) 2016, Prodys S.L.4 *5 * This adds support for sbs-charger compilant chips as defined here:6 * http://sbs-forum.org/specs/sbc110.pdf7 *8 * Implemetation based on sbs-battery.c9 */10 11#include <linux/init.h>12#include <linux/module.h>13#include <linux/kernel.h>14#include <linux/err.h>15#include <linux/power_supply.h>16#include <linux/i2c.h>17#include <linux/slab.h>18#include <linux/interrupt.h>19#include <linux/regmap.h>20#include <linux/bitops.h>21#include <linux/devm-helpers.h>22 23#define SBS_CHARGER_REG_SPEC_INFO 0x1124#define SBS_CHARGER_REG_STATUS 0x1325#define SBS_CHARGER_REG_ALARM_WARNING 0x1626 27#define SBS_CHARGER_STATUS_CHARGE_INHIBITED BIT(0)28#define SBS_CHARGER_STATUS_RES_COLD BIT(9)29#define SBS_CHARGER_STATUS_RES_HOT BIT(10)30#define SBS_CHARGER_STATUS_BATTERY_PRESENT BIT(14)31#define SBS_CHARGER_STATUS_AC_PRESENT BIT(15)32 33#define SBS_CHARGER_POLL_TIME 50034 35struct sbs_info {36 struct i2c_client *client;37 struct power_supply *power_supply;38 struct regmap *regmap;39 struct delayed_work work;40 unsigned int last_state;41};42 43static int sbs_get_property(struct power_supply *psy,44 enum power_supply_property psp,45 union power_supply_propval *val)46{47 struct sbs_info *chip = power_supply_get_drvdata(psy);48 unsigned int reg;49 50 reg = chip->last_state;51 52 switch (psp) {53 case POWER_SUPPLY_PROP_PRESENT:54 val->intval = !!(reg & SBS_CHARGER_STATUS_BATTERY_PRESENT);55 break;56 57 case POWER_SUPPLY_PROP_ONLINE:58 val->intval = !!(reg & SBS_CHARGER_STATUS_AC_PRESENT);59 break;60 61 case POWER_SUPPLY_PROP_STATUS:62 val->intval = POWER_SUPPLY_STATUS_UNKNOWN;63 64 if (!(reg & SBS_CHARGER_STATUS_BATTERY_PRESENT))65 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;66 else if (reg & SBS_CHARGER_STATUS_AC_PRESENT &&67 !(reg & SBS_CHARGER_STATUS_CHARGE_INHIBITED))68 val->intval = POWER_SUPPLY_STATUS_CHARGING;69 else70 val->intval = POWER_SUPPLY_STATUS_DISCHARGING;71 72 break;73 74 case POWER_SUPPLY_PROP_HEALTH:75 if (reg & SBS_CHARGER_STATUS_RES_COLD)76 val->intval = POWER_SUPPLY_HEALTH_COLD;77 if (reg & SBS_CHARGER_STATUS_RES_HOT)78 val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;79 else80 val->intval = POWER_SUPPLY_HEALTH_GOOD;81 82 break;83 84 default:85 return -EINVAL;86 }87 88 return 0;89}90 91static int sbs_check_state(struct sbs_info *chip)92{93 unsigned int reg;94 int ret;95 96 ret = regmap_read(chip->regmap, SBS_CHARGER_REG_STATUS, ®);97 if (!ret && reg != chip->last_state) {98 chip->last_state = reg;99 power_supply_changed(chip->power_supply);100 return 1;101 }102 103 return 0;104}105 106static void sbs_delayed_work(struct work_struct *work)107{108 struct sbs_info *chip = container_of(work, struct sbs_info, work.work);109 110 sbs_check_state(chip);111 112 schedule_delayed_work(&chip->work,113 msecs_to_jiffies(SBS_CHARGER_POLL_TIME));114}115 116static irqreturn_t sbs_irq_thread(int irq, void *data)117{118 struct sbs_info *chip = data;119 int ret;120 121 ret = sbs_check_state(chip);122 123 return ret ? IRQ_HANDLED : IRQ_NONE;124}125 126static enum power_supply_property sbs_properties[] = {127 POWER_SUPPLY_PROP_STATUS,128 POWER_SUPPLY_PROP_PRESENT,129 POWER_SUPPLY_PROP_ONLINE,130 POWER_SUPPLY_PROP_HEALTH,131};132 133static bool sbs_readable_reg(struct device *dev, unsigned int reg)134{135 return reg >= SBS_CHARGER_REG_SPEC_INFO;136}137 138static bool sbs_volatile_reg(struct device *dev, unsigned int reg)139{140 switch (reg) {141 case SBS_CHARGER_REG_STATUS:142 return true;143 }144 145 return false;146}147 148static const struct regmap_config sbs_regmap = {149 .reg_bits = 8,150 .val_bits = 16,151 .max_register = SBS_CHARGER_REG_ALARM_WARNING,152 .readable_reg = sbs_readable_reg,153 .volatile_reg = sbs_volatile_reg,154 .val_format_endian = REGMAP_ENDIAN_LITTLE, /* since based on SMBus */155};156 157static const struct power_supply_desc sbs_desc = {158 .name = "sbs-charger",159 .type = POWER_SUPPLY_TYPE_MAINS,160 .properties = sbs_properties,161 .num_properties = ARRAY_SIZE(sbs_properties),162 .get_property = sbs_get_property,163};164 165static int sbs_probe(struct i2c_client *client)166{167 struct power_supply_config psy_cfg = {};168 struct sbs_info *chip;169 int ret, val;170 171 chip = devm_kzalloc(&client->dev, sizeof(struct sbs_info), GFP_KERNEL);172 if (!chip)173 return -ENOMEM;174 175 chip->client = client;176 psy_cfg.of_node = client->dev.of_node;177 psy_cfg.drv_data = chip;178 179 i2c_set_clientdata(client, chip);180 181 chip->regmap = devm_regmap_init_i2c(client, &sbs_regmap);182 if (IS_ERR(chip->regmap))183 return PTR_ERR(chip->regmap);184 185 /*186 * Before we register, we need to make sure we can actually talk187 * to the battery.188 */189 ret = regmap_read(chip->regmap, SBS_CHARGER_REG_STATUS, &val);190 if (ret)191 return dev_err_probe(&client->dev, ret, "Failed to get device status\n");192 chip->last_state = val;193 194 chip->power_supply = devm_power_supply_register(&client->dev, &sbs_desc, &psy_cfg);195 if (IS_ERR(chip->power_supply))196 return dev_err_probe(&client->dev, PTR_ERR(chip->power_supply),197 "Failed to register power supply\n");198 199 /*200 * The sbs-charger spec doesn't impose the use of an interrupt. So in201 * the case it wasn't provided we use polling in order get the charger's202 * status.203 */204 if (client->irq) {205 ret = devm_request_threaded_irq(&client->dev, client->irq,206 NULL, sbs_irq_thread,207 IRQF_TRIGGER_FALLING | IRQF_ONESHOT,208 dev_name(&client->dev), chip);209 if (ret)210 return dev_err_probe(&client->dev, ret, "Failed to request irq\n");211 } else {212 ret = devm_delayed_work_autocancel(&client->dev, &chip->work,213 sbs_delayed_work);214 if (ret)215 return dev_err_probe(&client->dev, ret,216 "Failed to init work for polling\n");217 218 schedule_delayed_work(&chip->work,219 msecs_to_jiffies(SBS_CHARGER_POLL_TIME));220 }221 222 dev_info(&client->dev,223 "%s: smart charger device registered\n", client->name);224 225 return 0;226}227 228#ifdef CONFIG_OF229static const struct of_device_id sbs_dt_ids[] = {230 { .compatible = "sbs,sbs-charger" },231 { },232};233MODULE_DEVICE_TABLE(of, sbs_dt_ids);234#endif235 236static const struct i2c_device_id sbs_id[] = {237 { "sbs-charger" },238 { }239};240MODULE_DEVICE_TABLE(i2c, sbs_id);241 242static struct i2c_driver sbs_driver = {243 .probe = sbs_probe,244 .id_table = sbs_id,245 .driver = {246 .name = "sbs-charger",247 .of_match_table = of_match_ptr(sbs_dt_ids),248 },249};250module_i2c_driver(sbs_driver);251 252MODULE_AUTHOR("Nicolas Saenz Julienne <nicolassaenzj@gmail.com>");253MODULE_DESCRIPTION("SBS smart charger driver");254MODULE_LICENSE("GPL v2");255