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/gpio.h> 20 #include <linux/regmap.h> 21 #include <linux/of_gpio.h> 22 #include <linux/bitops.h> 23 24 #define SBS_CHARGER_REG_SPEC_INFO 0x11 25 #define SBS_CHARGER_REG_STATUS 0x13 26 #define SBS_CHARGER_REG_ALARM_WARNING 0x16 27 28 #define SBS_CHARGER_STATUS_CHARGE_INHIBITED BIT(1) 29 #define SBS_CHARGER_STATUS_RES_COLD BIT(9) 30 #define SBS_CHARGER_STATUS_RES_HOT BIT(10) 31 #define SBS_CHARGER_STATUS_BATTERY_PRESENT BIT(14) 32 #define SBS_CHARGER_STATUS_AC_PRESENT BIT(15) 33 34 #define SBS_CHARGER_POLL_TIME 500 35 36 struct sbs_info { 37 struct i2c_client *client; 38 struct power_supply *power_supply; 39 struct regmap *regmap; 40 struct delayed_work work; 41 unsigned int last_state; 42 }; 43 44 static int sbs_get_property(struct power_supply *psy, 45 enum power_supply_property psp, 46 union power_supply_propval *val) 47 { 48 struct sbs_info *chip = power_supply_get_drvdata(psy); 49 unsigned int reg; 50 51 reg = chip->last_state; 52 53 switch (psp) { 54 case POWER_SUPPLY_PROP_PRESENT: 55 val->intval = !!(reg & SBS_CHARGER_STATUS_BATTERY_PRESENT); 56 break; 57 58 case POWER_SUPPLY_PROP_ONLINE: 59 val->intval = !!(reg & SBS_CHARGER_STATUS_AC_PRESENT); 60 break; 61 62 case POWER_SUPPLY_PROP_STATUS: 63 val->intval = POWER_SUPPLY_STATUS_UNKNOWN; 64 65 if (!(reg & SBS_CHARGER_STATUS_BATTERY_PRESENT)) 66 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; 67 else if (reg & SBS_CHARGER_STATUS_AC_PRESENT && 68 !(reg & SBS_CHARGER_STATUS_CHARGE_INHIBITED)) 69 val->intval = POWER_SUPPLY_STATUS_CHARGING; 70 else 71 val->intval = POWER_SUPPLY_STATUS_DISCHARGING; 72 73 break; 74 75 case POWER_SUPPLY_PROP_HEALTH: 76 if (reg & SBS_CHARGER_STATUS_RES_COLD) 77 val->intval = POWER_SUPPLY_HEALTH_COLD; 78 if (reg & SBS_CHARGER_STATUS_RES_HOT) 79 val->intval = POWER_SUPPLY_HEALTH_OVERHEAT; 80 else 81 val->intval = POWER_SUPPLY_HEALTH_GOOD; 82 83 break; 84 85 default: 86 return -EINVAL; 87 } 88 89 return 0; 90 } 91 92 static int sbs_check_state(struct sbs_info *chip) 93 { 94 unsigned int reg; 95 int ret; 96 97 ret = regmap_read(chip->regmap, SBS_CHARGER_REG_STATUS, ®); 98 if (!ret && reg != chip->last_state) { 99 chip->last_state = reg; 100 power_supply_changed(chip->power_supply); 101 return 1; 102 } 103 104 return 0; 105 } 106 107 static void sbs_delayed_work(struct work_struct *work) 108 { 109 struct sbs_info *chip = container_of(work, struct sbs_info, work.work); 110 111 sbs_check_state(chip); 112 113 schedule_delayed_work(&chip->work, 114 msecs_to_jiffies(SBS_CHARGER_POLL_TIME)); 115 } 116 117 static irqreturn_t sbs_irq_thread(int irq, void *data) 118 { 119 struct sbs_info *chip = data; 120 int ret; 121 122 ret = sbs_check_state(chip); 123 124 return ret ? IRQ_HANDLED : IRQ_NONE; 125 } 126 127 static enum power_supply_property sbs_properties[] = { 128 POWER_SUPPLY_PROP_STATUS, 129 POWER_SUPPLY_PROP_PRESENT, 130 POWER_SUPPLY_PROP_ONLINE, 131 POWER_SUPPLY_PROP_HEALTH, 132 }; 133 134 static bool sbs_readable_reg(struct device *dev, unsigned int reg) 135 { 136 return reg >= SBS_CHARGER_REG_SPEC_INFO; 137 } 138 139 static bool sbs_volatile_reg(struct device *dev, unsigned int reg) 140 { 141 switch (reg) { 142 case SBS_CHARGER_REG_STATUS: 143 return true; 144 } 145 146 return false; 147 } 148 149 static const struct regmap_config sbs_regmap = { 150 .reg_bits = 8, 151 .val_bits = 16, 152 .max_register = SBS_CHARGER_REG_ALARM_WARNING, 153 .readable_reg = sbs_readable_reg, 154 .volatile_reg = sbs_volatile_reg, 155 .val_format_endian = REGMAP_ENDIAN_LITTLE, /* since based on SMBus */ 156 }; 157 158 static const struct power_supply_desc sbs_desc = { 159 .name = "sbs-charger", 160 .type = POWER_SUPPLY_TYPE_MAINS, 161 .properties = sbs_properties, 162 .num_properties = ARRAY_SIZE(sbs_properties), 163 .get_property = sbs_get_property, 164 }; 165 166 static int sbs_probe(struct i2c_client *client, 167 const struct i2c_device_id *id) 168 { 169 struct power_supply_config psy_cfg = {}; 170 struct sbs_info *chip; 171 int ret, val; 172 173 chip = devm_kzalloc(&client->dev, sizeof(struct sbs_info), GFP_KERNEL); 174 if (!chip) 175 return -ENOMEM; 176 177 chip->client = client; 178 psy_cfg.of_node = client->dev.of_node; 179 psy_cfg.drv_data = chip; 180 181 i2c_set_clientdata(client, chip); 182 183 chip->regmap = devm_regmap_init_i2c(client, &sbs_regmap); 184 if (IS_ERR(chip->regmap)) 185 return PTR_ERR(chip->regmap); 186 187 /* 188 * Before we register, we need to make sure we can actually talk 189 * to the battery. 190 */ 191 ret = regmap_read(chip->regmap, SBS_CHARGER_REG_STATUS, &val); 192 if (ret) { 193 dev_err(&client->dev, "Failed to get device status\n"); 194 return ret; 195 } 196 chip->last_state = val; 197 198 chip->power_supply = devm_power_supply_register(&client->dev, &sbs_desc, 199 &psy_cfg); 200 if (IS_ERR(chip->power_supply)) { 201 dev_err(&client->dev, "Failed to register power supply\n"); 202 return PTR_ERR(chip->power_supply); 203 } 204 205 /* 206 * The sbs-charger spec doesn't impose the use of an interrupt. So in 207 * the case it wasn't provided we use polling in order get the charger's 208 * status. 209 */ 210 if (client->irq) { 211 ret = devm_request_threaded_irq(&client->dev, client->irq, 212 NULL, sbs_irq_thread, 213 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 214 dev_name(&client->dev), chip); 215 if (ret) { 216 dev_err(&client->dev, "Failed to request irq, %d\n", ret); 217 return ret; 218 } 219 } else { 220 INIT_DELAYED_WORK(&chip->work, sbs_delayed_work); 221 schedule_delayed_work(&chip->work, 222 msecs_to_jiffies(SBS_CHARGER_POLL_TIME)); 223 } 224 225 dev_info(&client->dev, 226 "%s: smart charger device registered\n", client->name); 227 228 return 0; 229 } 230 231 static int sbs_remove(struct i2c_client *client) 232 { 233 struct sbs_info *chip = i2c_get_clientdata(client); 234 235 cancel_delayed_work_sync(&chip->work); 236 237 return 0; 238 } 239 240 #ifdef CONFIG_OF 241 static const struct of_device_id sbs_dt_ids[] = { 242 { .compatible = "sbs,sbs-charger" }, 243 { }, 244 }; 245 MODULE_DEVICE_TABLE(of, sbs_dt_ids); 246 #endif 247 248 static const struct i2c_device_id sbs_id[] = { 249 { "sbs-charger", 0 }, 250 { } 251 }; 252 MODULE_DEVICE_TABLE(i2c, sbs_id); 253 254 static struct i2c_driver sbs_driver = { 255 .probe = sbs_probe, 256 .remove = sbs_remove, 257 .id_table = sbs_id, 258 .driver = { 259 .name = "sbs-charger", 260 .of_match_table = of_match_ptr(sbs_dt_ids), 261 }, 262 }; 263 module_i2c_driver(sbs_driver); 264 265 MODULE_AUTHOR("Nicolas Saenz Julienne <nicolassaenzj@gmail.com>"); 266 MODULE_DESCRIPTION("SBS smart charger driver"); 267 MODULE_LICENSE("GPL v2"); 268