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 #include <linux/devm-helpers.h> 22 23 #define SBS_CHARGER_REG_SPEC_INFO 0x11 24 #define SBS_CHARGER_REG_STATUS 0x13 25 #define SBS_CHARGER_REG_ALARM_WARNING 0x16 26 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 500 34 35 struct 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 43 static 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 else 70 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 else 80 val->intval = POWER_SUPPLY_HEALTH_GOOD; 81 82 break; 83 84 default: 85 return -EINVAL; 86 } 87 88 return 0; 89 } 90 91 static 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 } 105 106 static 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 } 115 116 static 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 } 125 126 static 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 }; 132 133 static bool sbs_readable_reg(struct device *dev, unsigned int reg) 134 { 135 return reg >= SBS_CHARGER_REG_SPEC_INFO; 136 } 137 138 static 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 } 147 148 static 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 }; 156 157 static const struct power_supply_desc sbs_default_desc = { 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 { 166 struct power_supply_config psy_cfg = {}; 167 struct power_supply_desc *sbs_desc; 168 struct sbs_info *chip; 169 int ret, val; 170 171 sbs_desc = devm_kmemdup(&client->dev, &sbs_default_desc, 172 sizeof(*sbs_desc), GFP_KERNEL); 173 if (!sbs_desc) 174 return -ENOMEM; 175 176 sbs_desc->name = devm_kasprintf(&client->dev, GFP_KERNEL, "sbs-%s", 177 dev_name(&client->dev)); 178 if (!sbs_desc->name) 179 return -ENOMEM; 180 181 chip = devm_kzalloc(&client->dev, sizeof(struct sbs_info), GFP_KERNEL); 182 if (!chip) 183 return -ENOMEM; 184 185 chip->client = client; 186 psy_cfg.fwnode = dev_fwnode(&client->dev); 187 psy_cfg.drv_data = chip; 188 189 i2c_set_clientdata(client, chip); 190 191 chip->regmap = devm_regmap_init_i2c(client, &sbs_regmap); 192 if (IS_ERR(chip->regmap)) 193 return PTR_ERR(chip->regmap); 194 195 /* 196 * Before we register, we need to make sure we can actually talk 197 * to the battery. 198 */ 199 ret = regmap_read(chip->regmap, SBS_CHARGER_REG_STATUS, &val); 200 if (ret) 201 return dev_err_probe(&client->dev, ret, "Failed to get device status\n"); 202 chip->last_state = val; 203 204 chip->power_supply = devm_power_supply_register(&client->dev, sbs_desc, &psy_cfg); 205 if (IS_ERR(chip->power_supply)) 206 return dev_err_probe(&client->dev, PTR_ERR(chip->power_supply), 207 "Failed to register power supply\n"); 208 209 /* 210 * The sbs-charger spec doesn't impose the use of an interrupt. So in 211 * the case it wasn't provided we use polling in order get the charger's 212 * status. 213 */ 214 if (client->irq) { 215 ret = devm_request_threaded_irq(&client->dev, client->irq, 216 NULL, sbs_irq_thread, 217 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 218 dev_name(&client->dev), chip); 219 if (ret) 220 return dev_err_probe(&client->dev, ret, "Failed to request irq\n"); 221 } else { 222 ret = devm_delayed_work_autocancel(&client->dev, &chip->work, 223 sbs_delayed_work); 224 if (ret) 225 return dev_err_probe(&client->dev, ret, 226 "Failed to init work for polling\n"); 227 228 schedule_delayed_work(&chip->work, 229 msecs_to_jiffies(SBS_CHARGER_POLL_TIME)); 230 } 231 232 dev_info(&client->dev, 233 "%s: smart charger device registered\n", client->name); 234 235 return 0; 236 } 237 238 #ifdef CONFIG_OF 239 static const struct of_device_id sbs_dt_ids[] = { 240 { .compatible = "sbs,sbs-charger" }, 241 { }, 242 }; 243 MODULE_DEVICE_TABLE(of, sbs_dt_ids); 244 #endif 245 246 static const struct i2c_device_id sbs_id[] = { 247 { "sbs-charger" }, 248 { } 249 }; 250 MODULE_DEVICE_TABLE(i2c, sbs_id); 251 252 static struct i2c_driver sbs_driver = { 253 .probe = sbs_probe, 254 .id_table = sbs_id, 255 .driver = { 256 .name = "sbs-charger", 257 .of_match_table = of_match_ptr(sbs_dt_ids), 258 }, 259 }; 260 module_i2c_driver(sbs_driver); 261 262 MODULE_AUTHOR("Nicolas Saenz Julienne <nicolassaenzj@gmail.com>"); 263 MODULE_DESCRIPTION("SBS smart charger driver"); 264 MODULE_LICENSE("GPL v2"); 265