feat(battery): Initial battery charging state setection

app/drivers/sensor/battery/CMakeLists.txt

@@ -2,6 +2,7 @@
 # SPDX-License-Identifier: MIT
 
 zephyr_include_directories(.)
+zephyr_include_directories(${CMAKE_SOURCE_DIR}/include)
 
 zephyr_library()
 

app/drivers/sensor/battery/battery_common.c

@@ -7,6 +7,10 @@
 #include <errno.h>
 #include <drivers/sensor.h>
 
+#if CONFIG_ZMK_BATTERY_VOLTAGE_DIVIDER
+#include <drivers/sensor/battery/battery_voltage_divider.h>
+#endif
+
 #include "battery_common.h"
 
 int battery_channel_get(const struct battery_value *value, enum sensor_channel chan,
@@ -21,6 +25,13 @@ int battery_channel_get(const struct battery_value *value, enum sensor_channel c
         val_out->val1 = value->state_of_charge;
         val_out->val2 = 0;
         break;
+
+    #if CONFIG_ZMK_BATTERY_VOLTAGE_DIVIDER
+    case SENSOR_CHAN_CHARGING:
+        val_out->val1 = value->charging;
+        val_out->val2 = 0;
+        break;
+    #endif
 
     default:
         return -ENOTSUP;

app/drivers/sensor/battery/battery_common.h

@@ -13,6 +13,7 @@ struct battery_value {
     uint16_t adc_raw;
     uint16_t millivolts;
     uint8_t state_of_charge;
+    bool charging;
 };
 
 int battery_channel_get(const struct battery_value *value, enum sensor_channel chan,

app/drivers/sensor/battery/battery_voltage_divider.c

@@ -14,6 +14,7 @@
 #include <logging/log.h>
 
 #include "battery_common.h"
+#include <drivers/sensor/battery/battery_voltage_divider.h>
 
 LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
 
@@ -30,13 +31,15 @@ struct gpio_channel_config {
 struct bvd_config {
     struct io_channel_config io_channel;
     struct gpio_channel_config power_gpios;
+    struct gpio_channel_config chg_gpios;
     uint32_t output_ohm;
     uint32_t full_ohm;
 };
 
 struct bvd_data {
     const struct device *adc;
     const struct device *gpio;
+    const struct device *gpio2;
     struct adc_channel_cfg acc;
     struct adc_sequence as;
     struct battery_value value;
@@ -48,7 +51,7 @@ static int bvd_sample_fetch(const struct device *dev, enum sensor_channel chan)
     struct adc_sequence *as = &drv_data->as;
 
     // Make sure selected channel is supported
-    if (chan != SENSOR_CHAN_GAUGE_VOLTAGE && chan != SENSOR_CHAN_GAUGE_STATE_OF_CHARGE &&
+    if (chan != SENSOR_CHAN_GAUGE_VOLTAGE && chan != SENSOR_CHAN_GAUGE_STATE_OF_CHARGE && chan != SENSOR_CHAN_CHARGING &&
         chan != SENSOR_CHAN_ALL) {
         LOG_DBG("Selected channel is not supported: %d.", chan);
         return -ENOTSUP;
@@ -100,6 +103,17 @@ static int bvd_sample_fetch(const struct device *dev, enum sensor_channel chan)
         }
     }
 
+    if (drv_data->gpio2) {
+        int raw = gpio_pin_get(drv_data->gpio, drv_cfg->chg_gpios.pin);
+        if(raw == -EIO || raw == -EWOULDBLOCK) {
+            LOG_DBG("Failed to read chg status: %d", raw);
+            return raw;
+        } else {
+            bool charging = raw;
+            drv_data->value.charging = charging;
+        }
+    }
+
     return rc;
 }
 
@@ -140,6 +154,21 @@ static int bvd_init(const struct device *dev) {
         }
     }
 
+    if (drv_cfg->chg_gpios.label) {
+        drv_data->gpio2 = device_get_binding(drv_cfg->chg_gpios.label);
+        if (drv_data->gpio2 == NULL) {
+            LOG_ERR("Failed to get GPIO %s", drv_cfg->chg_gpios.label);
+            return -ENODEV;
+        }
+        rc = gpio_pin_configure(drv_data->gpio2, drv_cfg->chg_gpios.pin,
+                                GPIO_INPUT | drv_cfg->chg_gpios.flags);
+        if (rc != 0) {
+            LOG_ERR("Failed to configure input %s.%u: %d", drv_cfg->chg_gpios.label,
+                    drv_cfg->chg_gpios.pin, rc);
+            return rc;
+        }
+    }
+
     drv_data->as = (struct adc_sequence){
         .channels = BIT(0),
         .buffer = &drv_data->value.adc_raw,
@@ -181,6 +210,14 @@ static const struct bvd_config bvd_cfg = {
             DT_INST_GPIO_PIN(0, power_gpios),
             DT_INST_GPIO_FLAGS(0, power_gpios),
         },
+#endif
+#if DT_INST_NODE_HAS_PROP(0, chg_gpios)
+    .chg_gpios =
+        {
+            DT_INST_GPIO_LABEL(0, chg_gpios),
+            DT_INST_GPIO_PIN(0, chg_gpios),
+            DT_INST_GPIO_FLAGS(0, chg_gpios),
+        },
 #endif
     .output_ohm = DT_INST_PROP(0, output_ohms),
     .full_ohm = DT_INST_PROP(0, full_ohms),

app/drivers/zephyr/dts/bindings/sensor/zmk,battery-voltage-divider.yaml

@@ -11,3 +11,7 @@ properties:
   label:
     required: true
     type: string
+  chg-gpios:
+    required: false
+    type: phandle-array
+    description: "A GPIO pin to report charging state to"

app/include/drivers/sensor/battery/battery_voltage_divider.h

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2022 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#ifndef ZEPHYR_INCLUDE_DRIVERS_SENSOR_BATTERY_BATTERY_VOLTAGE_DIVIDER_H_
+#define ZEPHYR_INCLUDE_DRIVERS_SENSOR_BATTERY_BATTERY_VOLTAGE_DIVIDER_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <drivers/sensor.h>
+
+enum sensor_channel_bvd {
+	/** Charging state, bool **/
+	SENSOR_CHAN_CHARGING = SENSOR_CHAN_PRIV_START,
+};
+
+#endif

app/src/battery.c

@@ -19,9 +19,15 @@ LOG_MODULE_DECLARE(zmk, CONFIG_ZMK_LOG_LEVEL);
 #include <zmk/battery.h>
 #include <zmk/events/battery_state_changed.h>
 
+#if CONFIG_ZMK_BATTERY_VOLTAGE_DIVIDER
+#include "drivers/sensor/battery/battery_voltage_divider.h"
+#endif
+
 static uint8_t last_state_of_charge = 0;
+static bool charging = 0;
 
 uint8_t zmk_battery_state_of_charge() { return last_state_of_charge; }
+bool zmk_battery_charging() { return charging; }
 
 #if DT_HAS_CHOSEN(zmk_battery)
 static const struct device *const battery = DEVICE_DT_GET(DT_CHOSEN(zmk_battery));
@@ -64,6 +70,16 @@ static int zmk_battery_update(const struct device *battery) {
             (struct zmk_battery_state_changed){.state_of_charge = last_state_of_charge}));
     }
 
+    #if CONFIG_ZMK_BATTERY_VOLTAGE_DIVIDER
+    struct sensor_value charging_state;
+    rc = sensor_channel_get(battery, SENSOR_CHAN_CHARGING, &charging_state);
+    if (rc != 0) {
+        LOG_DBG("Failed to get battery charging status: %d", rc);
+        return rc;
+    }
+    charging = charging_state.val1;
+    #endif
+
     return rc;
 }