1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 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.pdf 7 * 8 * Implemetation based on sbs-battery.c 9 */ 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 22 #define SBS_CHARGER_REG_SPEC_INFO 0x11 23 #define SBS_CHARGER_REG_STATUS 0x13 24 #define SBS_CHARGER_REG_ALARM_WARNING 0x16 25 26 #define SBS_CHARGER_STATUS_CHARGE_INHIBITED BIT(1) 27 #define SBS_CHARGER_STATUS_RES_COLD BIT(9) 28 #define SBS_CHARGER_STATUS_RES_HOT BIT(10) 29 #define SBS_CHARGER_STATUS_BATTERY_PRESENT BIT(14) 30 #define SBS_CHARGER_STATUS_AC_PRESENT BIT(15) 31 32 #define SBS_CHARGER_POLL_TIME 500 33 34 struct sbs_info { 35 struct i2c_client *client; 36 struct power_supply *power_supply; 37 struct regmap *regmap; 38 struct delayed_work work; 39 unsigned int last_state; 40 }; 41 42 static int sbs_get_property(struct power_supply *psy, 43 enum power_supply_property psp, 44 union power_supply_propval *val) 45 { 46 struct sbs_info *chip = power_supply_get_drvdata(psy); 47 unsigned int reg; 48 49 reg = chip->last_state; 50 51 switch (psp) { 52 case POWER_SUPPLY_PROP_PRESENT: 53 val->intval = !!(reg & SBS_CHARGER_STATUS_BATTERY_PRESENT); 54 break; 55 56 case POWER_SUPPLY_PROP_ONLINE: 57 val->intval = !!(reg & SBS_CHARGER_STATUS_AC_PRESENT); 58 break; 59 60 case POWER_SUPPLY_PROP_STATUS: 61 val->intval = POWER_SUPPLY_STATUS_UNKNOWN; 62 63 if (!(reg & SBS_CHARGER_STATUS_BATTERY_PRESENT)) 64 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; 65 else if (reg & SBS_CHARGER_STATUS_AC_PRESENT && 66 !(reg & SBS_CHARGER_STATUS_CHARGE_INHIBITED)) 67 val->intval = POWER_SUPPLY_STATUS_CHARGING; 68 else 69 val->intval = POWER_SUPPLY_STATUS_DISCHARGING; 70 71 break; 72 73 case POWER_SUPPLY_PROP_HEALTH: 74 if (reg & SBS_CHARGER_STATUS_RES_COLD) 75 val->intval = POWER_SUPPLY_HEALTH_COLD; 76 if (reg & SBS_CHARGER_STATUS_RES_HOT) 77 val->intval = POWER_SUPPLY_HEALTH_OVERHEAT; 78 else 79 val->intval = POWER_SUPPLY_HEALTH_GOOD; 80 81 break; 82 83 default: 84 return -EINVAL; 85 } 86 87 return 0; 88 } 89 90 static int sbs_check_state(struct sbs_info *chip) 91 { 92 unsigned int reg; 93 int ret; 94 95 ret = regmap_read(chip->regmap, SBS_CHARGER_REG_STATUS, ®); 96 if (!ret && reg != chip->last_state) { 97 chip->last_state = reg; 98 power_supply_changed(chip->power_supply); 99 return 1; 100 } 101 102 return 0; 103 } 104 105 static void sbs_delayed_work(struct work_struct *work) 106 { 107 struct sbs_info *chip = container_of(work, struct sbs_info, work.work); 108 109 sbs_check_state(chip); 110 111 schedule_delayed_work(&chip->work, 112 msecs_to_jiffies(SBS_CHARGER_POLL_TIME)); 113 } 114 115 static irqreturn_t sbs_irq_thread(int irq, void *data) 116 { 117 struct sbs_info *chip = data; 118 int ret; 119 120 ret = sbs_check_state(chip); 121 122 return ret ? IRQ_HANDLED : IRQ_NONE; 123 } 124 125 static enum power_supply_property sbs_properties[] = { 126 POWER_SUPPLY_PROP_STATUS, 127 POWER_SUPPLY_PROP_PRESENT, 128 POWER_SUPPLY_PROP_ONLINE, 129 POWER_SUPPLY_PROP_HEALTH, 130 }; 131 132 static bool sbs_readable_reg(struct device *dev, unsigned int reg) 133 { 134 return reg >= SBS_CHARGER_REG_SPEC_INFO; 135 } 136 137 static bool sbs_volatile_reg(struct device *dev, unsigned int reg) 138 { 139 switch (reg) { 140 case SBS_CHARGER_REG_STATUS: 141 return true; 142 } 143 144 return false; 145 } 146 147 static const struct regmap_config sbs_regmap = { 148 .reg_bits = 8, 149 .val_bits = 16, 150 .max_register = SBS_CHARGER_REG_ALARM_WARNING, 151 .readable_reg = sbs_readable_reg, 152 .volatile_reg = sbs_volatile_reg, 153 .val_format_endian = REGMAP_ENDIAN_LITTLE, /* since based on SMBus */ 154 }; 155 156 static const struct power_supply_desc sbs_desc = { 157 .name = "sbs-charger", 158 .type = POWER_SUPPLY_TYPE_MAINS, 159 .properties = sbs_properties, 160 .num_properties = ARRAY_SIZE(sbs_properties), 161 .get_property = sbs_get_property, 162 }; 163 164 static int sbs_probe(struct i2c_client *client, 165 const struct i2c_device_id *id) 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 talk 187 * 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 in 201 * the case it wasn't provided we use polling in order get the charger's 202 * 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 INIT_DELAYED_WORK(&chip->work, sbs_delayed_work); 213 schedule_delayed_work(&chip->work, 214 msecs_to_jiffies(SBS_CHARGER_POLL_TIME)); 215 } 216 217 dev_info(&client->dev, 218 "%s: smart charger device registered\n", client->name); 219 220 return 0; 221 } 222 223 static int sbs_remove(struct i2c_client *client) 224 { 225 struct sbs_info *chip = i2c_get_clientdata(client); 226 227 cancel_delayed_work_sync(&chip->work); 228 229 return 0; 230 } 231 232 #ifdef CONFIG_OF 233 static const struct of_device_id sbs_dt_ids[] = { 234 { .compatible = "sbs,sbs-charger" }, 235 { }, 236 }; 237 MODULE_DEVICE_TABLE(of, sbs_dt_ids); 238 #endif 239 240 static const struct i2c_device_id sbs_id[] = { 241 { "sbs-charger", 0 }, 242 { } 243 }; 244 MODULE_DEVICE_TABLE(i2c, sbs_id); 245 246 static struct i2c_driver sbs_driver = { 247 .probe = sbs_probe, 248 .remove = sbs_remove, 249 .id_table = sbs_id, 250 .driver = { 251 .name = "sbs-charger", 252 .of_match_table = of_match_ptr(sbs_dt_ids), 253 }, 254 }; 255 module_i2c_driver(sbs_driver); 256 257 MODULE_AUTHOR("Nicolas Saenz Julienne <nicolassaenzj@gmail.com>"); 258 MODULE_DESCRIPTION("SBS smart charger driver"); 259 MODULE_LICENSE("GPL v2"); 260