@@ -629,6 +629,17 @@ config CHARGER_QCOM_SMBB
documentation for more detail. The base name for this driver is
'pm8941_charger'.
+config BATTERY_PM8916_BMS_VM
+ tristate "Qualcomm PM8916 BMS-VM support"
+ depends on MFD_SPMI_PMIC || COMPILE_TEST
+ help
+ Say Y to add support for Voltage Mode BMS block found in some
+ Qualcomm PMICs such as PM8916. This hardware block provides
+ battery voltage monitoring for the system.
+
+ To compile this driver as module, choose M here: the
+ module will be called pm8916_bms_vm.
+
config CHARGER_BQ2415X
tristate "TI BQ2415x battery charger driver"
depends on I2C
@@ -84,6 +84,7 @@ obj-$(CONFIG_CHARGER_MP2629) += mp2629_charger.o
obj-$(CONFIG_CHARGER_MT6360) += mt6360_charger.o
obj-$(CONFIG_CHARGER_MT6370) += mt6370-charger.o
obj-$(CONFIG_CHARGER_QCOM_SMBB) += qcom_smbb.o
+obj-$(CONFIG_BATTERY_PM8916_BMS_VM) += pm8916_bms_vm.o
obj-$(CONFIG_CHARGER_BQ2415X) += bq2415x_charger.o
obj-$(CONFIG_CHARGER_BQ24190) += bq24190_charger.o
obj-$(CONFIG_CHARGER_BQ24257) += bq24257_charger.o
new file mode 100644
@@ -0,0 +1,305 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2023, Nikita Travkin <nikita@trvn.ru>
+ */
+
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/timekeeping.h>
+#include <linux/mod_devicetable.h>
+
+#define PM8916_PERPH_TYPE 0x04
+#define PM8916_BMS_VM_TYPE 0x020D
+
+#define PM8916_SEC_ACCESS 0xD0
+#define PM8916_SEC_MAGIC 0xA5
+
+#define PM8916_BMS_VM_STATUS1 0x08
+#define PM8916_BMS_VM_FSM_STATE(x) (((x) & 0b00111000) >> 3)
+#define PM8916_BMS_VM_FSM_STATE_S2 0x2
+
+#define PM8916_BMS_VM_MODE_CTL 0x40
+#define PM8916_BMS_VM_MODE_FORCE_S3 (BIT(0) | BIT(1))
+#define PM8916_BMS_VM_MODE_NORMAL (BIT(1) | BIT(3))
+
+#define PM8916_BMS_VM_EN_CTL 0x46
+#define PM8916_BMS_ENABLED BIT(7)
+
+#define PM8916_BMS_VM_FIFO_LENGTH_CTL 0x47
+#define PM8916_BMS_VM_S1_SAMPLE_INTERVAL_CTL 0x55
+#define PM8916_BMS_VM_S2_SAMPLE_INTERVAL_CTL 0x56
+#define PM8916_BMS_VM_S3_S7_OCV_DATA0 0x6A
+#define PM8916_BMS_VM_BMS_FIFO_REG_0_LSB 0xC0
+
+/* Using only 1 fifo is broken in hardware */
+#define PM8916_BMS_VM_FIFO_COUNT 2 /* 2 .. 8 */
+
+#define PM8916_BMS_VM_S1_SAMPLE_INTERVAL 10
+#define PM8916_BMS_VM_S2_SAMPLE_INTERVAL 10
+
+struct pm8916_bms_vm_battery {
+ struct device *dev;
+ struct power_supply *battery;
+ struct power_supply_battery_info *info;
+ struct regmap *regmap;
+ unsigned int reg;
+ unsigned int last_ocv;
+ time64_t last_ocv_time;
+ unsigned int vbat_now;
+};
+
+static int pm8916_bms_vm_battery_get_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ struct pm8916_bms_vm_battery *bat = power_supply_get_drvdata(psy);
+ struct power_supply_battery_info *info = bat->info;
+ int supplied;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_STATUS:
+ supplied = power_supply_am_i_supplied(psy);
+
+ if (supplied < 0 && supplied != -ENODEV)
+ return supplied;
+ else if (supplied && supplied != -ENODEV)
+ val->intval = POWER_SUPPLY_STATUS_CHARGING;
+ else
+ val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+ return 0;
+
+ case POWER_SUPPLY_PROP_HEALTH:
+ if (bat->vbat_now < info->voltage_min_design_uv)
+ val->intval = POWER_SUPPLY_HEALTH_DEAD;
+ else if (bat->vbat_now > info->voltage_max_design_uv)
+ val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
+ else
+ val->intval = POWER_SUPPLY_HEALTH_GOOD;
+ return 0;
+
+ case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+ val->intval = bat->vbat_now;
+ return 0;
+
+ case POWER_SUPPLY_PROP_VOLTAGE_OCV:
+ /*
+ * Hardware only reliably measures OCV when the system is off or suspended.
+ * We expose the last known OCV value on boot, invalidating it after 180 seconds.
+ */
+ if (ktime_get_seconds() - bat->last_ocv_time > 180)
+ return -ENODATA;
+
+ val->intval = bat->last_ocv;
+ return 0;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static enum power_supply_property pm8916_bms_vm_battery_properties[] = {
+ POWER_SUPPLY_PROP_STATUS,
+ POWER_SUPPLY_PROP_VOLTAGE_NOW,
+ POWER_SUPPLY_PROP_VOLTAGE_OCV,
+ POWER_SUPPLY_PROP_HEALTH,
+};
+
+static irqreturn_t pm8916_bms_vm_fifo_update_done_irq(int irq, void *data)
+{
+ struct pm8916_bms_vm_battery *bat = data;
+ u16 vbat_data[PM8916_BMS_VM_FIFO_COUNT];
+ int ret;
+
+ ret = regmap_bulk_read(bat->regmap, bat->reg + PM8916_BMS_VM_BMS_FIFO_REG_0_LSB,
+ &vbat_data, PM8916_BMS_VM_FIFO_COUNT * 2);
+ if (ret)
+ return IRQ_HANDLED;
+
+ /*
+ * The VM-BMS hardware only collects voltage data and the software
+ * has to process it to calculate the OCV and SoC. Hardware provides
+ * up to 8 averaged measurements for software to take in account.
+ *
+ * Just use the last measured value for now to report the current
+ * battery voltage.
+ */
+ bat->vbat_now = vbat_data[PM8916_BMS_VM_FIFO_COUNT - 1] * 300;
+
+ power_supply_changed(bat->battery);
+
+ return IRQ_HANDLED;
+}
+
+static const struct power_supply_desc pm8916_bms_vm_battery_psy_desc = {
+ .name = "pm8916-bms-vm",
+ .type = POWER_SUPPLY_TYPE_BATTERY,
+ .properties = pm8916_bms_vm_battery_properties,
+ .num_properties = ARRAY_SIZE(pm8916_bms_vm_battery_properties),
+ .get_property = pm8916_bms_vm_battery_get_property,
+};
+
+static int pm8916_bms_vm_battery_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct pm8916_bms_vm_battery *bat;
+ struct power_supply_config psy_cfg = {};
+ int ret, irq;
+ unsigned int tmp;
+
+ bat = devm_kzalloc(dev, sizeof(*bat), GFP_KERNEL);
+ if (!bat)
+ return -ENOMEM;
+
+ bat->dev = dev;
+
+ bat->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+ if (!bat->regmap)
+ return -ENODEV;
+
+ ret = device_property_read_u32(dev, "reg", &bat->reg);
+ if (ret < 0)
+ return -EINVAL;
+
+ irq = platform_get_irq_byname(pdev, "fifo");
+ if (irq < 0)
+ return irq;
+
+ ret = devm_request_threaded_irq(dev, irq, NULL, pm8916_bms_vm_fifo_update_done_irq,
+ IRQF_ONESHOT, "pm8916_vm_bms", bat);
+ if (ret)
+ return ret;
+
+ ret = regmap_bulk_read(bat->regmap, bat->reg + PM8916_PERPH_TYPE, &tmp, 2);
+ if (ret)
+ goto comm_error;
+
+ if (tmp != PM8916_BMS_VM_TYPE)
+ return dev_err_probe(dev, -ENODEV, "Device reported wrong type: 0x%X\n", tmp);
+
+ ret = regmap_write(bat->regmap, bat->reg + PM8916_BMS_VM_S1_SAMPLE_INTERVAL_CTL,
+ PM8916_BMS_VM_S1_SAMPLE_INTERVAL);
+ if (ret)
+ goto comm_error;
+ ret = regmap_write(bat->regmap, bat->reg + PM8916_BMS_VM_S2_SAMPLE_INTERVAL_CTL,
+ PM8916_BMS_VM_S2_SAMPLE_INTERVAL);
+ if (ret)
+ goto comm_error;
+ ret = regmap_write(bat->regmap, bat->reg + PM8916_BMS_VM_FIFO_LENGTH_CTL,
+ PM8916_BMS_VM_FIFO_COUNT << 4 | PM8916_BMS_VM_FIFO_COUNT);
+ if (ret)
+ goto comm_error;
+ ret = regmap_write(bat->regmap,
+ bat->reg + PM8916_BMS_VM_EN_CTL, PM8916_BMS_ENABLED);
+ if (ret)
+ goto comm_error;
+
+ ret = regmap_bulk_read(bat->regmap,
+ bat->reg + PM8916_BMS_VM_S3_S7_OCV_DATA0, &tmp, 2);
+ if (ret)
+ goto comm_error;
+
+ bat->last_ocv_time = ktime_get_seconds();
+ bat->last_ocv = tmp * 300;
+ bat->vbat_now = bat->last_ocv;
+
+ psy_cfg.drv_data = bat;
+ psy_cfg.of_node = dev->of_node;
+
+ bat->battery = devm_power_supply_register(dev, &pm8916_bms_vm_battery_psy_desc, &psy_cfg);
+ if (IS_ERR(bat->battery))
+ return dev_err_probe(dev, PTR_ERR(bat->battery), "Unable to register battery\n");
+
+ ret = power_supply_get_battery_info(bat->battery, &bat->info);
+ if (ret)
+ return dev_err_probe(dev, ret, "Unable to get battery info\n");
+
+ platform_set_drvdata(pdev, bat);
+
+ return 0;
+
+comm_error:
+ return dev_err_probe(dev, ret, "Unable to communicate with device\n");
+}
+
+static int pm8916_bms_vm_battery_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ struct pm8916_bms_vm_battery *bat = platform_get_drvdata(pdev);
+ int ret;
+
+ /*
+ * Due to a hardware quirk the FSM doesn't switch states normally.
+ * Instead we unlock the debug registers and force S3 (Measure OCV/Sleep)
+ * mode every time we suspend.
+ */
+
+ ret = regmap_write(bat->regmap,
+ bat->reg + PM8916_SEC_ACCESS, PM8916_SEC_MAGIC);
+ if (ret)
+ goto error;
+ ret = regmap_write(bat->regmap,
+ bat->reg + PM8916_BMS_VM_MODE_CTL, PM8916_BMS_VM_MODE_FORCE_S3);
+ if (ret)
+ goto error;
+
+ return 0;
+
+error:
+ dev_err(bat->dev, "Failed to force S3 mode: %pe\n", ERR_PTR(ret));
+ return ret;
+}
+
+static int pm8916_bms_vm_battery_resume(struct platform_device *pdev)
+{
+ struct pm8916_bms_vm_battery *bat = platform_get_drvdata(pdev);
+ int ret;
+ unsigned int tmp;
+
+ ret = regmap_bulk_read(bat->regmap,
+ bat->reg + PM8916_BMS_VM_S3_S7_OCV_DATA0, &tmp, 2);
+
+ bat->last_ocv_time = ktime_get_seconds();
+ bat->last_ocv = tmp * 300;
+
+ ret = regmap_write(bat->regmap,
+ bat->reg + PM8916_SEC_ACCESS, PM8916_SEC_MAGIC);
+ if (ret)
+ goto error;
+ ret = regmap_write(bat->regmap,
+ bat->reg + PM8916_BMS_VM_MODE_CTL, PM8916_BMS_VM_MODE_NORMAL);
+ if (ret)
+ goto error;
+
+ return 0;
+
+error:
+ dev_err(bat->dev, "Failed to return normal mode: %pe\n", ERR_PTR(ret));
+ return ret;
+}
+
+static const struct of_device_id pm8916_bms_vm_battery_of_match[] = {
+ { .compatible = "qcom,pm8916-bms-vm", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, pm8916_bms_vm_battery_of_match);
+
+static struct platform_driver pm8916_bms_vm_battery_driver = {
+ .driver = {
+ .name = "pm8916-bms-vm",
+ .of_match_table = pm8916_bms_vm_battery_of_match,
+ },
+ .probe = pm8916_bms_vm_battery_probe,
+ .suspend = pm8916_bms_vm_battery_suspend,
+ .resume = pm8916_bms_vm_battery_resume,
+};
+module_platform_driver(pm8916_bms_vm_battery_driver);
+
+MODULE_DESCRIPTION("pm8916 BMS-VM driver");
+MODULE_AUTHOR("Nikita Travkin <nikita@trvn.ru>");
+MODULE_LICENSE("GPL");