--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <linux/devm-helpers.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/power_supply.h>
+#include <linux/types.h>
+
+/* Register Addresses (B=byte; W=word; S=string) */
+#define REGB_STATUS 0x02
+#define REGW_VOLTAGE_NOW 0x20
+#define REGW_CURRENT_NOW 0x24
+#define REGW_CAPACITY 0x28
+#define REGW_CHARGE_NOW 0x2a
+#define REGW_CHARGE_FULL 0x2c
+#define REGW_CYCLE_COUNT 0x3a
+#define REGW_CHARGE_FULL_DESIGN 0x3c
+#define REGW_VOLTAGE_MAX_DESIGN 0x3e
+#define REGW_SERIAL_NUMBER 0x44
+#define REGS_MANUFACTURER 0x46
+#define REGS_MODEL_NAME 0x52
+#define REGS_TECHNOLOGY 0x5a
+#define REGB_ONLINE 0x67
+
+struct srt_ec_device {
+ struct i2c_client *client;
+
+ struct power_supply *bat;
+ struct power_supply *psy;
+
+ struct gpio_desc *enable_gpiod;
+ struct delayed_work poll_work;
+
+ unsigned int technology;
+ unsigned int capacity;
+
+ const char *serial;
+ char manufacturer[13];
+ char model_name[10];
+};
+
+static const enum power_supply_property srt_bat_power_supply_props[] = {
+ POWER_SUPPLY_PROP_CAPACITY,
+ POWER_SUPPLY_PROP_CHARGE_NOW,
+ POWER_SUPPLY_PROP_CHARGE_FULL,
+ POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
+ POWER_SUPPLY_PROP_CURRENT_NOW,
+ POWER_SUPPLY_PROP_CYCLE_COUNT,
+ POWER_SUPPLY_PROP_MANUFACTURER,
+ POWER_SUPPLY_PROP_MODEL_NAME,
+ POWER_SUPPLY_PROP_ONLINE,
+ POWER_SUPPLY_PROP_PRESENT,
+ POWER_SUPPLY_PROP_SERIAL_NUMBER,
+ POWER_SUPPLY_PROP_STATUS,
+ POWER_SUPPLY_PROP_TECHNOLOGY,
+ POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
+ POWER_SUPPLY_PROP_VOLTAGE_NOW,
+};
+
+static const enum power_supply_property srt_psy_power_supply_props[] = {
+ POWER_SUPPLY_PROP_ONLINE,
+ POWER_SUPPLY_PROP_PRESENT,
+};
+
+static int srt_bat_get_value(struct i2c_client *client, int reg, int *val)
+{
+ int ret;
+
+ switch (reg) {
+ case REGW_CHARGE_NOW:
+ case REGW_CHARGE_FULL_DESIGN:
+ case REGW_CHARGE_FULL:
+ case REGW_VOLTAGE_MAX_DESIGN:
+ case REGW_VOLTAGE_NOW:
+ ret = i2c_smbus_read_word_data(client, reg);
+ if (ret < 0)
+ return ret;
+
+ *val = ret * 1000;
+ break;
+
+ case REGW_CURRENT_NOW:
+ ret = i2c_smbus_read_word_data(client, reg);
+ if (ret < 0)
+ return ret;
+
+ *val = (s16)ret * 1000;
+ break;
+
+ case REGW_CAPACITY:
+ case REGW_CYCLE_COUNT:
+ ret = i2c_smbus_read_word_data(client, reg);
+ if (ret < 0)
+ return ret;
+
+ *val = ret;
+ break;
+
+ case REGB_STATUS:
+ ret = i2c_smbus_read_byte_data(client, reg);
+ if (ret < 0)
+ return ret;
+
+ if (ret & BIT(0))
+ *val = POWER_SUPPLY_STATUS_CHARGING;
+ else
+ *val = POWER_SUPPLY_STATUS_DISCHARGING;
+ break;
+
+ case REGB_ONLINE:
+ ret = i2c_smbus_read_byte_data(client, reg);
+ if (ret < 0)
+ return ret;
+
+ *val = (ret & BIT(1)) >> 1;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int srt_bat_power_supply_get_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ struct srt_ec_device *srt = power_supply_get_drvdata(psy);
+ struct i2c_client *client = srt->client;
+ int ret = 0;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_MANUFACTURER:
+ val->strval = srt->manufacturer;
+ break;
+ case POWER_SUPPLY_PROP_MODEL_NAME:
+ val->strval = srt->model_name;
+ break;
+ case POWER_SUPPLY_PROP_SERIAL_NUMBER:
+ val->strval = srt->serial;
+ break;
+ case POWER_SUPPLY_PROP_CAPACITY:
+ ret = srt_bat_get_value(client, REGW_CAPACITY, &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_NOW:
+ ret = srt_bat_get_value(client, REGW_CHARGE_NOW, &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_FULL:
+ ret = srt_bat_get_value(client, REGW_CHARGE_FULL, &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
+ ret = srt_bat_get_value(client, REGW_CHARGE_FULL_DESIGN,
+ &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_CURRENT_NOW:
+ ret = srt_bat_get_value(client, REGW_CURRENT_NOW, &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_CYCLE_COUNT:
+ ret = srt_bat_get_value(client, REGW_CYCLE_COUNT, &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_PRESENT:
+ val->intval = 1;
+ break;
+ case POWER_SUPPLY_PROP_ONLINE:
+ ret = srt_bat_get_value(client, REGB_ONLINE, &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_STATUS:
+ if (srt->capacity < 100)
+ ret = srt_bat_get_value(client, REGB_STATUS, &val->intval);
+ else
+ val->intval = POWER_SUPPLY_STATUS_FULL;
+ break;
+ case POWER_SUPPLY_PROP_TECHNOLOGY:
+ val->intval = srt->technology;
+ break;
+ case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+ ret = srt_bat_get_value(client, REGW_VOLTAGE_MAX_DESIGN,
+ &val->intval);
+ break;
+ case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+ ret = srt_bat_get_value(client, REGW_VOLTAGE_NOW, &val->intval);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return ret;
+}
+
+static int srt_psy_power_supply_get_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ struct srt_ec_device *srt = power_supply_get_drvdata(psy);
+ struct i2c_client *client = srt->client;
+ int ret;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_ONLINE:
+ case POWER_SUPPLY_PROP_PRESENT:
+ ret = i2c_smbus_read_byte_data(client, REGB_ONLINE);
+ if (ret < 0)
+ return ret;
+
+ val->intval = ret & BIT(0);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void srt_bat_poll_work(struct work_struct *work)
+{
+ struct srt_ec_device *srt =
+ container_of(work, struct srt_ec_device, poll_work.work);
+ int ret, capacity;
+
+ ret = srt_bat_get_value(srt->client, REGW_CAPACITY, &capacity);
+ if (!ret && capacity != srt->capacity) {
+ srt->capacity = capacity;
+ power_supply_changed(srt->bat);
+ }
+
+ /* continuously send uevent notification */
+ schedule_delayed_work(&srt->poll_work, 30 * HZ);
+}
+
+static irqreturn_t srt_psy_detect_irq(int irq, void *dev_id)
+{
+ struct srt_ec_device *srt = dev_id;
+
+ power_supply_changed(srt->psy);
+
+ return IRQ_HANDLED;
+}
+
+static const struct power_supply_desc srt_bat_power_supply_desc = {
+ .name = "surface-rt-battery",
+ .type = POWER_SUPPLY_TYPE_BATTERY,
+ .properties = srt_bat_power_supply_props,
+ .num_properties = ARRAY_SIZE(srt_bat_power_supply_props),
+ .get_property = srt_bat_power_supply_get_property,
+ .external_power_changed = power_supply_changed,
+};
+
+static const struct power_supply_desc srt_psy_power_supply_desc = {
+ .name = "surface-rt-ac-adapter",
+ .type = POWER_SUPPLY_TYPE_MAINS,
+ .properties = srt_psy_power_supply_props,
+ .num_properties = ARRAY_SIZE(srt_psy_power_supply_props),
+ .get_property = srt_psy_power_supply_get_property,
+};
+
+static char *battery_supplied_to[] = { "surface-rt-battery" };
+
+static int srt_ec_probe(struct i2c_client *client)
+{
+ struct power_supply_config bat_cfg = {};
+ struct power_supply_config psy_cfg = {};
+ struct device *dev = &client->dev;
+ struct srt_ec_device *srt;
+ char str_buf[4];
+ int ret;
+
+ srt = devm_kzalloc(dev, sizeof(*srt), GFP_KERNEL);
+ if (!srt)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, srt);
+ srt->client = client;
+
+ srt->enable_gpiod = devm_gpiod_get(dev, "enable", GPIOD_OUT_HIGH);
+ if (IS_ERR(srt->enable_gpiod))
+ return dev_err_probe(dev, PTR_ERR(srt->enable_gpiod),
+ "failed to get enable gpio\n");
+
+ /* wait till EC is ready */
+ usleep_range(1000, 1500);
+
+ ret = i2c_smbus_read_word_data(client, REGW_SERIAL_NUMBER);
+ if (ret < 0)
+ return ret;
+
+ srt->serial = devm_kasprintf(dev, GFP_KERNEL, "%04x", ret);
+ if (!srt->serial)
+ return -ENOMEM;
+
+ ret = i2c_smbus_read_i2c_block_data(client, REGS_MANUFACTURER,
+ sizeof(srt->manufacturer) - 1,
+ srt->manufacturer);
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_smbus_read_i2c_block_data(client, REGS_MODEL_NAME,
+ sizeof(srt->model_name) - 1,
+ srt->model_name);
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_smbus_read_i2c_block_data(client, REGS_TECHNOLOGY,
+ sizeof(str_buf), str_buf);
+ if (ret < 0)
+ return ret;
+
+ if (!strncmp(str_buf, "LION", 4))
+ srt->technology = POWER_SUPPLY_TECHNOLOGY_LION;
+ else
+ srt->technology = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
+
+ bat_cfg.drv_data = srt;
+ bat_cfg.fwnode = dev_fwnode(dev);
+
+ srt->bat = devm_power_supply_register(dev, &srt_bat_power_supply_desc,
+ &bat_cfg);
+ if (IS_ERR(srt->bat))
+ return dev_err_probe(dev, PTR_ERR(srt->bat),
+ "failed to register battery power supply\n");
+
+ psy_cfg.drv_data = srt;
+ psy_cfg.fwnode = dev_fwnode(dev);
+ psy_cfg.supplied_to = battery_supplied_to;
+ psy_cfg.num_supplicants = ARRAY_SIZE(battery_supplied_to);
+
+ srt->psy = devm_power_supply_register(dev, &srt_psy_power_supply_desc,
+ &psy_cfg);
+ if (IS_ERR(srt->psy))
+ return dev_err_probe(dev, PTR_ERR(srt->psy),
+ "failed to register AC power supply\n");
+
+ ret = devm_request_threaded_irq(dev, client->irq, NULL, srt_psy_detect_irq,
+ IRQF_ONESHOT, client->name, srt);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "failed to request interrupt\n");
+
+ ret = devm_delayed_work_autocancel(dev, &srt->poll_work, srt_bat_poll_work);
+ if (ret < 0)
+ return ret;
+
+ schedule_delayed_work(&srt->poll_work, HZ);
+
+ return 0;
+}
+
+static int srt_ec_suspend(struct device *dev)
+{
+ struct srt_ec_device *srt = dev_get_drvdata(dev);
+
+ cancel_delayed_work_sync(&srt->poll_work);
+
+ return 0;
+}
+
+static int srt_ec_resume(struct device *dev)
+{
+ struct srt_ec_device *srt = dev_get_drvdata(dev);
+
+ schedule_delayed_work(&srt->poll_work, HZ);
+
+ return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(srt_ec_pm_ops, srt_ec_suspend, srt_ec_resume);
+
+static const struct of_device_id srt_ec_of_match[] = {
+ { .compatible = "microsoft,surface-rt-ec" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, srt_ec_of_match);
+
+static struct i2c_driver srt_ec_driver = {
+ .driver = {
+ .name = "surface-rt-ec",
+ .of_match_table = srt_ec_of_match,
+ .pm = &srt_ec_pm_ops,
+ },
+ .probe = srt_ec_probe,
+};
+module_i2c_driver(srt_ec_driver);
+
+MODULE_AUTHOR("Jonas Schwöbel <jonasschwoebel@yahoo.de>");
+MODULE_DESCRIPTION("Surface RT Embedded Controller driver");
+MODULE_LICENSE("GPL");
projects / thirdparty / linux.git / commitdiff
