--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Battery driver for 7th-generation Microsoft Surface devices via Surface
+ * System Aggregator Module (SSAM).
+ *
+ * Copyright (C) 2019-2021 Maximilian Luz <luzmaximilian@gmail.com>
+ */
+
+#include <asm/unaligned.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/power_supply.h>
+#include <linux/sysfs.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+
+#include <linux/surface_aggregator/device.h>
+
+
+/* -- SAM interface. -------------------------------------------------------- */
+
+enum sam_event_cid_bat {
+ SAM_EVENT_CID_BAT_BIX = 0x15,
+ SAM_EVENT_CID_BAT_BST = 0x16,
+ SAM_EVENT_CID_BAT_ADP = 0x17,
+ SAM_EVENT_CID_BAT_PROT = 0x18,
+ SAM_EVENT_CID_BAT_DPTF = 0x53,
+};
+
+enum sam_battery_sta {
+ SAM_BATTERY_STA_OK = 0x0f,
+ SAM_BATTERY_STA_PRESENT = 0x10,
+};
+
+enum sam_battery_state {
+ SAM_BATTERY_STATE_DISCHARGING = BIT(0),
+ SAM_BATTERY_STATE_CHARGING = BIT(1),
+ SAM_BATTERY_STATE_CRITICAL = BIT(2),
+};
+
+enum sam_battery_power_unit {
+ SAM_BATTERY_POWER_UNIT_mW = 0,
+ SAM_BATTERY_POWER_UNIT_mA = 1,
+};
+
+/* Equivalent to data returned in ACPI _BIX method, revision 0. */
+struct spwr_bix {
+ u8 revision;
+ __le32 power_unit;
+ __le32 design_cap;
+ __le32 last_full_charge_cap;
+ __le32 technology;
+ __le32 design_voltage;
+ __le32 design_cap_warn;
+ __le32 design_cap_low;
+ __le32 cycle_count;
+ __le32 measurement_accuracy;
+ __le32 max_sampling_time;
+ __le32 min_sampling_time;
+ __le32 max_avg_interval;
+ __le32 min_avg_interval;
+ __le32 bat_cap_granularity_1;
+ __le32 bat_cap_granularity_2;
+ __u8 model[21];
+ __u8 serial[11];
+ __u8 type[5];
+ __u8 oem_info[21];
+} __packed;
+
+static_assert(sizeof(struct spwr_bix) == 119);
+
+/* Equivalent to data returned in ACPI _BST method. */
+struct spwr_bst {
+ __le32 state;
+ __le32 present_rate;
+ __le32 remaining_cap;
+ __le32 present_voltage;
+} __packed;
+
+static_assert(sizeof(struct spwr_bst) == 16);
+
+#define SPWR_BIX_REVISION 0
+#define SPWR_BATTERY_VALUE_UNKNOWN 0xffffffff
+
+/* Get battery status (_STA) */
+SSAM_DEFINE_SYNC_REQUEST_CL_R(ssam_bat_get_sta, __le32, {
+ .target_category = SSAM_SSH_TC_BAT,
+ .command_id = 0x01,
+});
+
+/* Get battery static information (_BIX). */
+SSAM_DEFINE_SYNC_REQUEST_CL_R(ssam_bat_get_bix, struct spwr_bix, {
+ .target_category = SSAM_SSH_TC_BAT,
+ .command_id = 0x02,
+});
+
+/* Get battery dynamic information (_BST). */
+SSAM_DEFINE_SYNC_REQUEST_CL_R(ssam_bat_get_bst, struct spwr_bst, {
+ .target_category = SSAM_SSH_TC_BAT,
+ .command_id = 0x03,
+});
+
+/* Set battery trip point (_BTP). */
+SSAM_DEFINE_SYNC_REQUEST_CL_W(ssam_bat_set_btp, __le32, {
+ .target_category = SSAM_SSH_TC_BAT,
+ .command_id = 0x04,
+});
+
+
+/* -- Device structures. ---------------------------------------------------- */
+
+struct spwr_psy_properties {
+ const char *name;
+ struct ssam_event_registry registry;
+};
+
+struct spwr_battery_device {
+ struct ssam_device *sdev;
+
+ char name[32];
+ struct power_supply *psy;
+ struct power_supply_desc psy_desc;
+
+ struct delayed_work update_work;
+
+ struct ssam_event_notifier notif;
+
+ struct mutex lock; /* Guards access to state data below. */
+ unsigned long timestamp;
+
+ __le32 sta;
+ struct spwr_bix bix;
+ struct spwr_bst bst;
+ u32 alarm;
+};
+
+
+/* -- Module parameters. ---------------------------------------------------- */
+
+static unsigned int cache_time = 1000;
+module_param(cache_time, uint, 0644);
+MODULE_PARM_DESC(cache_time, "battery state caching time in milliseconds [default: 1000]");
+
+
+/* -- State management. ----------------------------------------------------- */
+
+/*
+ * Delay for battery update quirk. See spwr_external_power_changed() below
+ * for more details.
+ */
+#define SPWR_AC_BAT_UPDATE_DELAY msecs_to_jiffies(5000)
+
+static bool spwr_battery_present(struct spwr_battery_device *bat)
+{
+ lockdep_assert_held(&bat->lock);
+
+ return le32_to_cpu(bat->sta) & SAM_BATTERY_STA_PRESENT;
+}
+
+static int spwr_battery_load_sta(struct spwr_battery_device *bat)
+{
+ lockdep_assert_held(&bat->lock);
+
+ return ssam_retry(ssam_bat_get_sta, bat->sdev, &bat->sta);
+}
+
+static int spwr_battery_load_bix(struct spwr_battery_device *bat)
+{
+ int status;
+
+ lockdep_assert_held(&bat->lock);
+
+ if (!spwr_battery_present(bat))
+ return 0;
+
+ status = ssam_retry(ssam_bat_get_bix, bat->sdev, &bat->bix);
+
+ /* Enforce NULL terminated strings in case anything goes wrong... */
+ bat->bix.model[ARRAY_SIZE(bat->bix.model) - 1] = 0;
+ bat->bix.serial[ARRAY_SIZE(bat->bix.serial) - 1] = 0;
+ bat->bix.type[ARRAY_SIZE(bat->bix.type) - 1] = 0;
+ bat->bix.oem_info[ARRAY_SIZE(bat->bix.oem_info) - 1] = 0;
+
+ return status;
+}
+
+static int spwr_battery_load_bst(struct spwr_battery_device *bat)
+{
+ lockdep_assert_held(&bat->lock);
+
+ if (!spwr_battery_present(bat))
+ return 0;
+
+ return ssam_retry(ssam_bat_get_bst, bat->sdev, &bat->bst);
+}
+
+static int spwr_battery_set_alarm_unlocked(struct spwr_battery_device *bat, u32 value)
+{
+ __le32 value_le = cpu_to_le32(value);
+
+ lockdep_assert_held(&bat->lock);
+
+ bat->alarm = value;
+ return ssam_retry(ssam_bat_set_btp, bat->sdev, &value_le);
+}
+
+static int spwr_battery_update_bst_unlocked(struct spwr_battery_device *bat, bool cached)
+{
+ unsigned long cache_deadline = bat->timestamp + msecs_to_jiffies(cache_time);
+ int status;
+
+ lockdep_assert_held(&bat->lock);
+
+ if (cached && bat->timestamp && time_is_after_jiffies(cache_deadline))
+ return 0;
+
+ status = spwr_battery_load_sta(bat);
+ if (status)
+ return status;
+
+ status = spwr_battery_load_bst(bat);
+ if (status)
+ return status;
+
+ bat->timestamp = jiffies;
+ return 0;
+}
+
+static int spwr_battery_update_bst(struct spwr_battery_device *bat, bool cached)
+{
+ int status;
+
+ mutex_lock(&bat->lock);
+ status = spwr_battery_update_bst_unlocked(bat, cached);
+ mutex_unlock(&bat->lock);
+
+ return status;
+}
+
+static int spwr_battery_update_bix_unlocked(struct spwr_battery_device *bat)
+{
+ int status;
+
+ lockdep_assert_held(&bat->lock);
+
+ status = spwr_battery_load_sta(bat);
+ if (status)
+ return status;
+
+ status = spwr_battery_load_bix(bat);
+ if (status)
+ return status;
+
+ status = spwr_battery_load_bst(bat);
+ if (status)
+ return status;
+
+ if (bat->bix.revision != SPWR_BIX_REVISION)
+ dev_warn(&bat->sdev->dev, "unsupported battery revision: %u\n", bat->bix.revision);
+
+ bat->timestamp = jiffies;
+ return 0;
+}
+
+static u32 sprw_battery_get_full_cap_safe(struct spwr_battery_device *bat)
+{
+ u32 full_cap = get_unaligned_le32(&bat->bix.last_full_charge_cap);
+
+ lockdep_assert_held(&bat->lock);
+
+ if (full_cap == 0 || full_cap == SPWR_BATTERY_VALUE_UNKNOWN)
+ full_cap = get_unaligned_le32(&bat->bix.design_cap);
+
+ return full_cap;
+}
+
+static bool spwr_battery_is_full(struct spwr_battery_device *bat)
+{
+ u32 state = get_unaligned_le32(&bat->bst.state);
+ u32 full_cap = sprw_battery_get_full_cap_safe(bat);
+ u32 remaining_cap = get_unaligned_le32(&bat->bst.remaining_cap);
+
+ lockdep_assert_held(&bat->lock);
+
+ return full_cap != SPWR_BATTERY_VALUE_UNKNOWN && full_cap != 0 &&
+ remaining_cap != SPWR_BATTERY_VALUE_UNKNOWN &&
+ remaining_cap >= full_cap &&
+ state == 0;
+}
+
+static int spwr_battery_recheck_full(struct spwr_battery_device *bat)
+{
+ bool present;
+ u32 unit;
+ int status;
+
+ mutex_lock(&bat->lock);
+ unit = get_unaligned_le32(&bat->bix.power_unit);
+ present = spwr_battery_present(bat);
+
+ status = spwr_battery_update_bix_unlocked(bat);
+ if (status)
+ goto out;
+
+ /* If battery has been attached, (re-)initialize alarm. */
+ if (!present && spwr_battery_present(bat)) {
+ u32 cap_warn = get_unaligned_le32(&bat->bix.design_cap_warn);
+
+ status = spwr_battery_set_alarm_unlocked(bat, cap_warn);
+ if (status)
+ goto out;
+ }
+
+ /*
+ * Warn if the unit has changed. This is something we genuinely don't
+ * expect to happen, so make this a big warning. If it does, we'll
+ * need to add support for it.
+ */
+ WARN_ON(unit != get_unaligned_le32(&bat->bix.power_unit));
+
+out:
+ mutex_unlock(&bat->lock);
+
+ if (!status)
+ power_supply_changed(bat->psy);
+
+ return status;
+}
+
+static int spwr_battery_recheck_status(struct spwr_battery_device *bat)
+{
+ int status;
+
+ status = spwr_battery_update_bst(bat, false);
+ if (!status)
+ power_supply_changed(bat->psy);
+
+ return status;
+}
+
+static u32 spwr_notify_bat(struct ssam_event_notifier *nf, const struct ssam_event *event)
+{
+ struct spwr_battery_device *bat = container_of(nf, struct spwr_battery_device, notif);
+ int status;
+
+ dev_dbg(&bat->sdev->dev, "power event (cid = %#04x, iid = %#04x, tid = %#04x)\n",
+ event->command_id, event->instance_id, event->target_id);
+
+ switch (event->command_id) {
+ case SAM_EVENT_CID_BAT_BIX:
+ status = spwr_battery_recheck_full(bat);
+ break;
+
+ case SAM_EVENT_CID_BAT_BST:
+ status = spwr_battery_recheck_status(bat);
+ break;
+
+ case SAM_EVENT_CID_BAT_PROT:
+ /*
+ * TODO: Implement support for battery protection status change
+ * event.
+ */
+ status = 0;
+ break;
+
+ case SAM_EVENT_CID_BAT_DPTF:
+ /*
+ * TODO: Implement support for DPTF event.
+ */
+ status = 0;
+ break;
+
+ default:
+ return 0;
+ }
+
+ return ssam_notifier_from_errno(status) | SSAM_NOTIF_HANDLED;
+}
+
+static void spwr_battery_update_bst_workfn(struct work_struct *work)
+{
+ struct delayed_work *dwork = to_delayed_work(work);
+ struct spwr_battery_device *bat;
+ int status;
+
+ bat = container_of(dwork, struct spwr_battery_device, update_work);
+
+ status = spwr_battery_update_bst(bat, false);
+ if (status) {
+ dev_err(&bat->sdev->dev, "failed to update battery state: %d\n", status);
+ return;
+ }
+
+ power_supply_changed(bat->psy);
+}
+
+static void spwr_external_power_changed(struct power_supply *psy)
+{
+ struct spwr_battery_device *bat = power_supply_get_drvdata(psy);
+
+ /*
+ * Handle battery update quirk: When the battery is fully charged (or
+ * charged up to the limit imposed by the UEFI battery limit) and the
+ * adapter is plugged in or removed, the EC does not send a separate
+ * event for the state (charging/discharging) change. Furthermore it
+ * may take some time until the state is updated on the battery.
+ * Schedule an update to solve this.
+ */
+
+ schedule_delayed_work(&bat->update_work, SPWR_AC_BAT_UPDATE_DELAY);
+}
+
+
+/* -- Properties. ----------------------------------------------------------- */
+
+static const enum power_supply_property spwr_battery_props_chg[] = {
+ POWER_SUPPLY_PROP_STATUS,
+ POWER_SUPPLY_PROP_PRESENT,
+ POWER_SUPPLY_PROP_TECHNOLOGY,
+ POWER_SUPPLY_PROP_CYCLE_COUNT,
+ POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
+ POWER_SUPPLY_PROP_VOLTAGE_NOW,
+ POWER_SUPPLY_PROP_CURRENT_NOW,
+ POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
+ POWER_SUPPLY_PROP_CHARGE_FULL,
+ POWER_SUPPLY_PROP_CHARGE_NOW,
+ POWER_SUPPLY_PROP_CAPACITY,
+ POWER_SUPPLY_PROP_CAPACITY_LEVEL,
+ POWER_SUPPLY_PROP_MODEL_NAME,
+ POWER_SUPPLY_PROP_MANUFACTURER,
+ POWER_SUPPLY_PROP_SERIAL_NUMBER,
+};
+
+static const enum power_supply_property spwr_battery_props_eng[] = {
+ POWER_SUPPLY_PROP_STATUS,
+ POWER_SUPPLY_PROP_PRESENT,
+ POWER_SUPPLY_PROP_TECHNOLOGY,
+ POWER_SUPPLY_PROP_CYCLE_COUNT,
+ POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
+ POWER_SUPPLY_PROP_VOLTAGE_NOW,
+ POWER_SUPPLY_PROP_POWER_NOW,
+ POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
+ POWER_SUPPLY_PROP_ENERGY_FULL,
+ POWER_SUPPLY_PROP_ENERGY_NOW,
+ POWER_SUPPLY_PROP_CAPACITY,
+ POWER_SUPPLY_PROP_CAPACITY_LEVEL,
+ POWER_SUPPLY_PROP_MODEL_NAME,
+ POWER_SUPPLY_PROP_MANUFACTURER,
+ POWER_SUPPLY_PROP_SERIAL_NUMBER,
+};
+
+static int spwr_battery_prop_status(struct spwr_battery_device *bat)
+{
+ u32 state = get_unaligned_le32(&bat->bst.state);
+ u32 present_rate = get_unaligned_le32(&bat->bst.present_rate);
+
+ lockdep_assert_held(&bat->lock);
+
+ if (state & SAM_BATTERY_STATE_DISCHARGING)
+ return POWER_SUPPLY_STATUS_DISCHARGING;
+
+ if (state & SAM_BATTERY_STATE_CHARGING)
+ return POWER_SUPPLY_STATUS_CHARGING;
+
+ if (spwr_battery_is_full(bat))
+ return POWER_SUPPLY_STATUS_FULL;
+
+ if (present_rate == 0)
+ return POWER_SUPPLY_STATUS_NOT_CHARGING;
+
+ return POWER_SUPPLY_STATUS_UNKNOWN;
+}
+
+static int spwr_battery_prop_technology(struct spwr_battery_device *bat)
+{
+ lockdep_assert_held(&bat->lock);
+
+ if (!strcasecmp("NiCd", bat->bix.type))
+ return POWER_SUPPLY_TECHNOLOGY_NiCd;
+
+ if (!strcasecmp("NiMH", bat->bix.type))
+ return POWER_SUPPLY_TECHNOLOGY_NiMH;
+
+ if (!strcasecmp("LION", bat->bix.type))
+ return POWER_SUPPLY_TECHNOLOGY_LION;
+
+ if (!strncasecmp("LI-ION", bat->bix.type, 6))
+ return POWER_SUPPLY_TECHNOLOGY_LION;
+
+ if (!strcasecmp("LiP", bat->bix.type))
+ return POWER_SUPPLY_TECHNOLOGY_LIPO;
+
+ return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
+}
+
+static int spwr_battery_prop_capacity(struct spwr_battery_device *bat)
+{
+ u32 full_cap = sprw_battery_get_full_cap_safe(bat);
+ u32 remaining_cap = get_unaligned_le32(&bat->bst.remaining_cap);
+
+ lockdep_assert_held(&bat->lock);
+
+ if (full_cap == 0 || full_cap == SPWR_BATTERY_VALUE_UNKNOWN)
+ return -ENODATA;
+
+ if (remaining_cap == SPWR_BATTERY_VALUE_UNKNOWN)
+ return -ENODATA;
+
+ return remaining_cap * 100 / full_cap;
+}
+
+static int spwr_battery_prop_capacity_level(struct spwr_battery_device *bat)
+{
+ u32 state = get_unaligned_le32(&bat->bst.state);
+ u32 remaining_cap = get_unaligned_le32(&bat->bst.remaining_cap);
+
+ lockdep_assert_held(&bat->lock);
+
+ if (state & SAM_BATTERY_STATE_CRITICAL)
+ return POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
+
+ if (spwr_battery_is_full(bat))
+ return POWER_SUPPLY_CAPACITY_LEVEL_FULL;
+
+ if (remaining_cap <= bat->alarm)
+ return POWER_SUPPLY_CAPACITY_LEVEL_LOW;
+
+ return POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
+}
+
+static int spwr_battery_get_property(struct power_supply *psy, enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ struct spwr_battery_device *bat = power_supply_get_drvdata(psy);
+ u32 value;
+ int status;
+
+ mutex_lock(&bat->lock);
+
+ status = spwr_battery_update_bst_unlocked(bat, true);
+ if (status)
+ goto out;
+
+ /* Abort if battery is not present. */
+ if (!spwr_battery_present(bat) && psp != POWER_SUPPLY_PROP_PRESENT) {
+ status = -ENODEV;
+ goto out;
+ }
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_STATUS:
+ val->intval = spwr_battery_prop_status(bat);
+ break;
+
+ case POWER_SUPPLY_PROP_PRESENT:
+ val->intval = spwr_battery_present(bat);
+ break;
+
+ case POWER_SUPPLY_PROP_TECHNOLOGY:
+ val->intval = spwr_battery_prop_technology(bat);
+ break;
+
+ case POWER_SUPPLY_PROP_CYCLE_COUNT:
+ value = get_unaligned_le32(&bat->bix.cycle_count);
+ if (value != SPWR_BATTERY_VALUE_UNKNOWN)
+ val->intval = value;
+ else
+ status = -ENODATA;
+ break;
+
+ case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
+ value = get_unaligned_le32(&bat->bix.design_voltage);
+ if (value != SPWR_BATTERY_VALUE_UNKNOWN)
+ val->intval = value * 1000;
+ else
+ status = -ENODATA;
+ break;
+
+ case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+ value = get_unaligned_le32(&bat->bst.present_voltage);
+ if (value != SPWR_BATTERY_VALUE_UNKNOWN)
+ val->intval = value * 1000;
+ else
+ status = -ENODATA;
+ break;
+
+ case POWER_SUPPLY_PROP_CURRENT_NOW:
+ case POWER_SUPPLY_PROP_POWER_NOW:
+ value = get_unaligned_le32(&bat->bst.present_rate);
+ if (value != SPWR_BATTERY_VALUE_UNKNOWN)
+ val->intval = value * 1000;
+ else
+ status = -ENODATA;
+ break;
+
+ case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
+ case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
+ value = get_unaligned_le32(&bat->bix.design_cap);
+ if (value != SPWR_BATTERY_VALUE_UNKNOWN)
+ val->intval = value * 1000;
+ else
+ status = -ENODATA;
+ break;
+
+ case POWER_SUPPLY_PROP_CHARGE_FULL:
+ case POWER_SUPPLY_PROP_ENERGY_FULL:
+ value = get_unaligned_le32(&bat->bix.last_full_charge_cap);
+ if (value != SPWR_BATTERY_VALUE_UNKNOWN)
+ val->intval = value * 1000;
+ else
+ status = -ENODATA;
+ break;
+
+ case POWER_SUPPLY_PROP_CHARGE_NOW:
+ case POWER_SUPPLY_PROP_ENERGY_NOW:
+ value = get_unaligned_le32(&bat->bst.remaining_cap);
+ if (value != SPWR_BATTERY_VALUE_UNKNOWN)
+ val->intval = value * 1000;
+ else
+ status = -ENODATA;
+ break;
+
+ case POWER_SUPPLY_PROP_CAPACITY:
+ val->intval = spwr_battery_prop_capacity(bat);
+ break;
+
+ case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
+ val->intval = spwr_battery_prop_capacity_level(bat);
+ break;
+
+ case POWER_SUPPLY_PROP_MODEL_NAME:
+ val->strval = bat->bix.model;
+ break;
+
+ case POWER_SUPPLY_PROP_MANUFACTURER:
+ val->strval = bat->bix.oem_info;
+ break;
+
+ case POWER_SUPPLY_PROP_SERIAL_NUMBER:
+ val->strval = bat->bix.serial;
+ break;
+
+ default:
+ status = -EINVAL;
+ break;
+ }
+
+out:
+ mutex_unlock(&bat->lock);
+ return status;
+}
+
+
+/* -- Alarm attribute. ------------------------------------------------------ */
+
+static ssize_t alarm_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct power_supply *psy = dev_get_drvdata(dev);
+ struct spwr_battery_device *bat = power_supply_get_drvdata(psy);
+ int status;
+
+ mutex_lock(&bat->lock);
+ status = sysfs_emit(buf, "%d\n", bat->alarm * 1000);
+ mutex_unlock(&bat->lock);
+
+ return status;
+}
+
+static ssize_t alarm_store(struct device *dev, struct device_attribute *attr, const char *buf,
+ size_t count)
+{
+ struct power_supply *psy = dev_get_drvdata(dev);
+ struct spwr_battery_device *bat = power_supply_get_drvdata(psy);
+ unsigned long value;
+ int status;
+
+ status = kstrtoul(buf, 0, &value);
+ if (status)
+ return status;
+
+ mutex_lock(&bat->lock);
+
+ if (!spwr_battery_present(bat)) {
+ mutex_unlock(&bat->lock);
+ return -ENODEV;
+ }
+
+ status = spwr_battery_set_alarm_unlocked(bat, value / 1000);
+ if (status) {
+ mutex_unlock(&bat->lock);
+ return status;
+ }
+
+ mutex_unlock(&bat->lock);
+ return count;
+}
+
+DEVICE_ATTR_RW(alarm);
+
+static struct attribute *spwr_battery_attrs[] = {
+ &dev_attr_alarm.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(spwr_battery);
+
+
+/* -- Device setup. --------------------------------------------------------- */
+
+static void spwr_battery_init(struct spwr_battery_device *bat, struct ssam_device *sdev,
+ struct ssam_event_registry registry, const char *name)
+{
+ mutex_init(&bat->lock);
+ strncpy(bat->name, name, ARRAY_SIZE(bat->name) - 1);
+
+ bat->sdev = sdev;
+
+ bat->notif.base.priority = 1;
+ bat->notif.base.fn = spwr_notify_bat;
+ bat->notif.event.reg = registry;
+ bat->notif.event.id.target_category = sdev->uid.category;
+ bat->notif.event.id.instance = 0;
+ bat->notif.event.mask = SSAM_EVENT_MASK_STRICT;
+ bat->notif.event.flags = SSAM_EVENT_SEQUENCED;
+
+ bat->psy_desc.name = bat->name;
+ bat->psy_desc.type = POWER_SUPPLY_TYPE_BATTERY;
+ bat->psy_desc.get_property = spwr_battery_get_property;
+
+ INIT_DELAYED_WORK(&bat->update_work, spwr_battery_update_bst_workfn);
+}
+
+static int spwr_battery_register(struct spwr_battery_device *bat)
+{
+ struct power_supply_config psy_cfg = {};
+ __le32 sta;
+ int status;
+
+ /* Make sure the device is there and functioning properly. */
+ status = ssam_retry(ssam_bat_get_sta, bat->sdev, &sta);
+ if (status)
+ return status;
+
+ if ((le32_to_cpu(sta) & SAM_BATTERY_STA_OK) != SAM_BATTERY_STA_OK)
+ return -ENODEV;
+
+ /* Satisfy lockdep although we are in an exclusive context here. */
+ mutex_lock(&bat->lock);
+
+ status = spwr_battery_update_bix_unlocked(bat);
+ if (status) {
+ mutex_unlock(&bat->lock);
+ return status;
+ }
+
+ if (spwr_battery_present(bat)) {
+ u32 cap_warn = get_unaligned_le32(&bat->bix.design_cap_warn);
+
+ status = spwr_battery_set_alarm_unlocked(bat, cap_warn);
+ if (status) {
+ mutex_unlock(&bat->lock);
+ return status;
+ }
+ }
+
+ mutex_unlock(&bat->lock);
+
+ bat->psy_desc.external_power_changed = spwr_external_power_changed;
+
+ switch (get_unaligned_le32(&bat->bix.power_unit)) {
+ case SAM_BATTERY_POWER_UNIT_mW:
+ bat->psy_desc.properties = spwr_battery_props_eng;
+ bat->psy_desc.num_properties = ARRAY_SIZE(spwr_battery_props_eng);
+ break;
+
+ case SAM_BATTERY_POWER_UNIT_mA:
+ bat->psy_desc.properties = spwr_battery_props_chg;
+ bat->psy_desc.num_properties = ARRAY_SIZE(spwr_battery_props_chg);
+ break;
+
+ default:
+ dev_err(&bat->sdev->dev, "unsupported battery power unit: %u\n",
+ get_unaligned_le32(&bat->bix.power_unit));
+ return -EINVAL;
+ }
+
+ psy_cfg.drv_data = bat;
+ psy_cfg.attr_grp = spwr_battery_groups;
+
+ bat->psy = devm_power_supply_register(&bat->sdev->dev, &bat->psy_desc, &psy_cfg);
+ if (IS_ERR(bat->psy))
+ return PTR_ERR(bat->psy);
+
+ return ssam_notifier_register(bat->sdev->ctrl, &bat->notif);
+}
+
+
+/* -- Driver setup. --------------------------------------------------------- */
+
+static int __maybe_unused surface_battery_resume(struct device *dev)
+{
+ return spwr_battery_recheck_full(dev_get_drvdata(dev));
+}
+SIMPLE_DEV_PM_OPS(surface_battery_pm_ops, NULL, surface_battery_resume);
+
+static int surface_battery_probe(struct ssam_device *sdev)
+{
+ const struct spwr_psy_properties *p;
+ struct spwr_battery_device *bat;
+
+ p = ssam_device_get_match_data(sdev);
+ if (!p)
+ return -ENODEV;
+
+ bat = devm_kzalloc(&sdev->dev, sizeof(*bat), GFP_KERNEL);
+ if (!bat)
+ return -ENOMEM;
+
+ spwr_battery_init(bat, sdev, p->registry, p->name);
+ ssam_device_set_drvdata(sdev, bat);
+
+ return spwr_battery_register(bat);
+}
+
+static void surface_battery_remove(struct ssam_device *sdev)
+{
+ struct spwr_battery_device *bat = ssam_device_get_drvdata(sdev);
+
+ ssam_notifier_unregister(sdev->ctrl, &bat->notif);
+ cancel_delayed_work_sync(&bat->update_work);
+}
+
+static const struct spwr_psy_properties spwr_psy_props_bat1 = {
+ .name = "BAT1",
+ .registry = SSAM_EVENT_REGISTRY_SAM,
+};
+
+static const struct spwr_psy_properties spwr_psy_props_bat2_sb3 = {
+ .name = "BAT2",
+ .registry = SSAM_EVENT_REGISTRY_KIP,
+};
+
+static const struct ssam_device_id surface_battery_match[] = {
+ { SSAM_SDEV(BAT, 0x01, 0x01, 0x00), (unsigned long)&spwr_psy_props_bat1 },
+ { SSAM_SDEV(BAT, 0x02, 0x01, 0x00), (unsigned long)&spwr_psy_props_bat2_sb3 },
+ { },
+};
+MODULE_DEVICE_TABLE(ssam, surface_battery_match);
+
+static struct ssam_device_driver surface_battery_driver = {
+ .probe = surface_battery_probe,
+ .remove = surface_battery_remove,
+ .match_table = surface_battery_match,
+ .driver = {
+ .name = "surface_battery",
+ .pm = &surface_battery_pm_ops,
+ .probe_type = PROBE_PREFER_ASYNCHRONOUS,
+ },
+};
+module_ssam_device_driver(surface_battery_driver);
+
+MODULE_AUTHOR("Maximilian Luz <luzmaximilian@gmail.com>");
+MODULE_DESCRIPTION("Battery driver for Surface System Aggregator Module");
+MODULE_LICENSE("GPL");
projects / platform / kernel / linux-rpi.git / commitdiff