306 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (c) 2023, Nikita Travkin <nikita@trvn.ru>4 */5 6#include <linux/errno.h>7#include <linux/module.h>8#include <linux/platform_device.h>9#include <linux/power_supply.h>10#include <linux/property.h>11#include <linux/regmap.h>12#include <linux/slab.h>13#include <linux/delay.h>14#include <linux/interrupt.h>15#include <linux/timekeeping.h>16#include <linux/mod_devicetable.h>17 18#define PM8916_PERPH_TYPE 0x0419#define PM8916_BMS_VM_TYPE 0x020D20 21#define PM8916_SEC_ACCESS 0xD022#define PM8916_SEC_MAGIC 0xA523 24#define PM8916_BMS_VM_STATUS1 0x0825#define PM8916_BMS_VM_FSM_STATE(x) (((x) & 0b00111000) >> 3)26#define PM8916_BMS_VM_FSM_STATE_S2 0x227 28#define PM8916_BMS_VM_MODE_CTL 0x4029#define PM8916_BMS_VM_MODE_FORCE_S3 (BIT(0) | BIT(1))30#define PM8916_BMS_VM_MODE_NORMAL (BIT(1) | BIT(3))31 32#define PM8916_BMS_VM_EN_CTL 0x4633#define PM8916_BMS_ENABLED BIT(7)34 35#define PM8916_BMS_VM_FIFO_LENGTH_CTL 0x4736#define PM8916_BMS_VM_S1_SAMPLE_INTERVAL_CTL 0x5537#define PM8916_BMS_VM_S2_SAMPLE_INTERVAL_CTL 0x5638#define PM8916_BMS_VM_S3_S7_OCV_DATA0 0x6A39#define PM8916_BMS_VM_BMS_FIFO_REG_0_LSB 0xC040 41/* Using only 1 fifo is broken in hardware */42#define PM8916_BMS_VM_FIFO_COUNT 2 /* 2 .. 8 */43 44#define PM8916_BMS_VM_S1_SAMPLE_INTERVAL 1045#define PM8916_BMS_VM_S2_SAMPLE_INTERVAL 1046 47struct pm8916_bms_vm_battery {48 struct device *dev;49 struct power_supply *battery;50 struct power_supply_battery_info *info;51 struct regmap *regmap;52 unsigned int reg;53 unsigned int last_ocv;54 time64_t last_ocv_time;55 unsigned int vbat_now;56};57 58static int pm8916_bms_vm_battery_get_property(struct power_supply *psy,59 enum power_supply_property psp,60 union power_supply_propval *val)61{62 struct pm8916_bms_vm_battery *bat = power_supply_get_drvdata(psy);63 struct power_supply_battery_info *info = bat->info;64 int supplied;65 66 switch (psp) {67 case POWER_SUPPLY_PROP_STATUS:68 supplied = power_supply_am_i_supplied(psy);69 70 if (supplied < 0 && supplied != -ENODEV)71 return supplied;72 else if (supplied && supplied != -ENODEV)73 val->intval = POWER_SUPPLY_STATUS_CHARGING;74 else75 val->intval = POWER_SUPPLY_STATUS_DISCHARGING;76 return 0;77 78 case POWER_SUPPLY_PROP_HEALTH:79 if (bat->vbat_now < info->voltage_min_design_uv)80 val->intval = POWER_SUPPLY_HEALTH_DEAD;81 else if (bat->vbat_now > info->voltage_max_design_uv)82 val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;83 else84 val->intval = POWER_SUPPLY_HEALTH_GOOD;85 return 0;86 87 case POWER_SUPPLY_PROP_VOLTAGE_NOW:88 val->intval = bat->vbat_now;89 return 0;90 91 case POWER_SUPPLY_PROP_VOLTAGE_OCV:92 /*93 * Hardware only reliably measures OCV when the system is off or suspended.94 * We expose the last known OCV value on boot, invalidating it after 180 seconds.95 */96 if (ktime_get_seconds() - bat->last_ocv_time > 180)97 return -ENODATA;98 99 val->intval = bat->last_ocv;100 return 0;101 102 default:103 return -EINVAL;104 }105}106 107static enum power_supply_property pm8916_bms_vm_battery_properties[] = {108 POWER_SUPPLY_PROP_STATUS,109 POWER_SUPPLY_PROP_VOLTAGE_NOW,110 POWER_SUPPLY_PROP_VOLTAGE_OCV,111 POWER_SUPPLY_PROP_HEALTH,112};113 114static irqreturn_t pm8916_bms_vm_fifo_update_done_irq(int irq, void *data)115{116 struct pm8916_bms_vm_battery *bat = data;117 u16 vbat_data[PM8916_BMS_VM_FIFO_COUNT];118 int ret;119 120 ret = regmap_bulk_read(bat->regmap, bat->reg + PM8916_BMS_VM_BMS_FIFO_REG_0_LSB,121 &vbat_data, PM8916_BMS_VM_FIFO_COUNT * 2);122 if (ret)123 return IRQ_HANDLED;124 125 /*126 * The VM-BMS hardware only collects voltage data and the software127 * has to process it to calculate the OCV and SoC. Hardware provides128 * up to 8 averaged measurements for software to take in account.129 *130 * Just use the last measured value for now to report the current131 * battery voltage.132 */133 bat->vbat_now = vbat_data[PM8916_BMS_VM_FIFO_COUNT - 1] * 300;134 135 power_supply_changed(bat->battery);136 137 return IRQ_HANDLED;138}139 140static const struct power_supply_desc pm8916_bms_vm_battery_psy_desc = {141 .name = "pm8916-bms-vm",142 .type = POWER_SUPPLY_TYPE_BATTERY,143 .properties = pm8916_bms_vm_battery_properties,144 .num_properties = ARRAY_SIZE(pm8916_bms_vm_battery_properties),145 .get_property = pm8916_bms_vm_battery_get_property,146};147 148static int pm8916_bms_vm_battery_probe(struct platform_device *pdev)149{150 struct device *dev = &pdev->dev;151 struct pm8916_bms_vm_battery *bat;152 struct power_supply_config psy_cfg = {};153 int ret, irq;154 unsigned int tmp;155 156 bat = devm_kzalloc(dev, sizeof(*bat), GFP_KERNEL);157 if (!bat)158 return -ENOMEM;159 160 bat->dev = dev;161 162 bat->regmap = dev_get_regmap(pdev->dev.parent, NULL);163 if (!bat->regmap)164 return -ENODEV;165 166 ret = device_property_read_u32(dev, "reg", &bat->reg);167 if (ret < 0)168 return -EINVAL;169 170 irq = platform_get_irq_byname(pdev, "fifo");171 if (irq < 0)172 return irq;173 174 ret = devm_request_threaded_irq(dev, irq, NULL, pm8916_bms_vm_fifo_update_done_irq,175 IRQF_ONESHOT, "pm8916_vm_bms", bat);176 if (ret)177 return ret;178 179 ret = regmap_bulk_read(bat->regmap, bat->reg + PM8916_PERPH_TYPE, &tmp, 2);180 if (ret)181 goto comm_error;182 183 if (tmp != PM8916_BMS_VM_TYPE)184 return dev_err_probe(dev, -ENODEV, "Device reported wrong type: 0x%X\n", tmp);185 186 ret = regmap_write(bat->regmap, bat->reg + PM8916_BMS_VM_S1_SAMPLE_INTERVAL_CTL,187 PM8916_BMS_VM_S1_SAMPLE_INTERVAL);188 if (ret)189 goto comm_error;190 ret = regmap_write(bat->regmap, bat->reg + PM8916_BMS_VM_S2_SAMPLE_INTERVAL_CTL,191 PM8916_BMS_VM_S2_SAMPLE_INTERVAL);192 if (ret)193 goto comm_error;194 ret = regmap_write(bat->regmap, bat->reg + PM8916_BMS_VM_FIFO_LENGTH_CTL,195 PM8916_BMS_VM_FIFO_COUNT << 4 | PM8916_BMS_VM_FIFO_COUNT);196 if (ret)197 goto comm_error;198 ret = regmap_write(bat->regmap,199 bat->reg + PM8916_BMS_VM_EN_CTL, PM8916_BMS_ENABLED);200 if (ret)201 goto comm_error;202 203 ret = regmap_bulk_read(bat->regmap,204 bat->reg + PM8916_BMS_VM_S3_S7_OCV_DATA0, &tmp, 2);205 if (ret)206 goto comm_error;207 208 bat->last_ocv_time = ktime_get_seconds();209 bat->last_ocv = tmp * 300;210 bat->vbat_now = bat->last_ocv;211 212 psy_cfg.drv_data = bat;213 psy_cfg.of_node = dev->of_node;214 215 bat->battery = devm_power_supply_register(dev, &pm8916_bms_vm_battery_psy_desc, &psy_cfg);216 if (IS_ERR(bat->battery))217 return dev_err_probe(dev, PTR_ERR(bat->battery), "Unable to register battery\n");218 219 ret = power_supply_get_battery_info(bat->battery, &bat->info);220 if (ret)221 return dev_err_probe(dev, ret, "Unable to get battery info\n");222 223 platform_set_drvdata(pdev, bat);224 225 return 0;226 227comm_error:228 return dev_err_probe(dev, ret, "Unable to communicate with device\n");229}230 231static int pm8916_bms_vm_battery_suspend(struct platform_device *pdev, pm_message_t state)232{233 struct pm8916_bms_vm_battery *bat = platform_get_drvdata(pdev);234 int ret;235 236 /*237 * Due to a hardware quirk the FSM doesn't switch states normally.238 * Instead we unlock the debug registers and force S3 (Measure OCV/Sleep)239 * mode every time we suspend.240 */241 242 ret = regmap_write(bat->regmap,243 bat->reg + PM8916_SEC_ACCESS, PM8916_SEC_MAGIC);244 if (ret)245 goto error;246 ret = regmap_write(bat->regmap,247 bat->reg + PM8916_BMS_VM_MODE_CTL, PM8916_BMS_VM_MODE_FORCE_S3);248 if (ret)249 goto error;250 251 return 0;252 253error:254 dev_err(bat->dev, "Failed to force S3 mode: %pe\n", ERR_PTR(ret));255 return ret;256}257 258static int pm8916_bms_vm_battery_resume(struct platform_device *pdev)259{260 struct pm8916_bms_vm_battery *bat = platform_get_drvdata(pdev);261 int ret;262 unsigned int tmp;263 264 ret = regmap_bulk_read(bat->regmap,265 bat->reg + PM8916_BMS_VM_S3_S7_OCV_DATA0, &tmp, 2);266 267 bat->last_ocv_time = ktime_get_seconds();268 bat->last_ocv = tmp * 300;269 270 ret = regmap_write(bat->regmap,271 bat->reg + PM8916_SEC_ACCESS, PM8916_SEC_MAGIC);272 if (ret)273 goto error;274 ret = regmap_write(bat->regmap,275 bat->reg + PM8916_BMS_VM_MODE_CTL, PM8916_BMS_VM_MODE_NORMAL);276 if (ret)277 goto error;278 279 return 0;280 281error:282 dev_err(bat->dev, "Failed to return normal mode: %pe\n", ERR_PTR(ret));283 return ret;284}285 286static const struct of_device_id pm8916_bms_vm_battery_of_match[] = {287 { .compatible = "qcom,pm8916-bms-vm", },288 {}289};290MODULE_DEVICE_TABLE(of, pm8916_bms_vm_battery_of_match);291 292static struct platform_driver pm8916_bms_vm_battery_driver = {293 .driver = {294 .name = "pm8916-bms-vm",295 .of_match_table = pm8916_bms_vm_battery_of_match,296 },297 .probe = pm8916_bms_vm_battery_probe,298 .suspend = pm8916_bms_vm_battery_suspend,299 .resume = pm8916_bms_vm_battery_resume,300};301module_platform_driver(pm8916_bms_vm_battery_driver);302 303MODULE_DESCRIPTION("pm8916 BMS-VM driver");304MODULE_AUTHOR("Nikita Travkin <nikita@trvn.ru>");305MODULE_LICENSE("GPL");306