@@ -157,6 +157,19 @@ config BATTERY_WM97XX
help
Say Y to enable support for battery measured by WM97xx aux port.
+config MANAGER_SBS
+ tristate "Smart Battery System Manager"
+ depends on I2C && I2C_MUX
+ help
+ Say Y here to include support for Smart Battery System Manager
+ ICs. The driver reports online and charging status via sysfs.
+ It presents itself also as I2C mux which allows to bind
+ smart battery driver to its ports.
+ Supported is for example LTC1760.
+
+ This driver can also be built as a module. If so, the module will be
+ called sbs-manager.
+
config BATTERY_SBS
tristate "SBS Compliant gas gauge"
depends on I2C
@@ -22,6 +22,7 @@ obj-$(CONFIG_BATTERY_DS2760) += ds2760_battery.o
obj-$(CONFIG_BATTERY_DS2780) += ds2780_battery.o
obj-$(CONFIG_BATTERY_DS2781) += ds2781_battery.o
obj-$(CONFIG_BATTERY_DS2782) += ds2782_battery.o
+obj-$(CONFIG_MANAGER_SBS) += sbs-manager.o
obj-$(CONFIG_BATTERY_GAUGE_LTC2941) += ltc2941-battery-gauge.o
obj-$(CONFIG_BATTERY_GOLDFISH) += goldfish_battery.o
obj-$(CONFIG_BATTERY_PMU) += pmu_battery.o
new file mode 100644
@@ -0,0 +1,325 @@
+/*
+ * Driver for SBS compliant Smart Battery System Managers
+ *
+ * The device communicates via i2c at address 0x0a and multiplexes access to up
+ * to four smart batteries at address 0x0b.
+ *
+ * Via sysfs interface the online state and charge type are presented.
+ *
+ * Datasheet SBSM: http://sbs-forum.org/specs/sbsm100b.pdf
+ * Datasheet LTC1760: http://cds.linear.com/docs/en/datasheet/1760fb.pdf
+ *
+ * Karl-Heinz Schneider <karl-heinz@schneider-inet.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/power_supply.h>
+
+#define SBSM_MAX_BATS 4
+#define SBSM_RETRY_CNT 3
+
+/* registers addresses */
+#define SBSM_CMD_BATSYSSTATE 0x01
+#define SBSM_CMD_BATSYSSTATECONT 0x02
+#define SBSM_CMD_BATSYSINFO 0x04
+#define SBSM_CMD_LTC 0x3c
+
+struct sbsm_data {
+ struct i2c_client *client;
+ struct i2c_mux_core *muxc;
+
+ struct power_supply *psy;
+
+ int cur_chan; /* currently selected channel */
+ bool is_ltc1760; /* special capabilities */
+};
+
+static enum power_supply_property sbsm_props[] = {
+ POWER_SUPPLY_PROP_ONLINE,
+ POWER_SUPPLY_PROP_CHARGE_TYPE,
+};
+
+static int sbsm_read_word(struct i2c_client *client, u8 address)
+{
+ int reg, retries = SBSM_RETRY_CNT;
+
+ while (retries > 0) {
+ reg = i2c_smbus_read_word_data(client, address);
+ if (reg >= 0)
+ break;
+ --retries;
+ }
+
+ if (reg < 0) {
+ dev_err(&client->dev, "failed to read register %i\n",
+ (int)address);
+ return reg;
+ }
+
+ return le16_to_cpu(reg);
+}
+
+static int sbsm_write_word(struct i2c_client *client, u8 address, u16 word)
+{
+ int ret, retries = SBSM_RETRY_CNT;
+
+ word = cpu_to_le16(word);
+ while (retries > 0) {
+ ret = i2c_smbus_write_word_data(client, address, word);
+ if (ret >= 0)
+ break;
+ --retries;
+ }
+ if (ret < 0)
+ dev_err(&client->dev, "failed to write to register %i\n",
+ (int)address);
+
+ return ret;
+}
+
+static int sbsm_get_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ struct sbsm_data *data = power_supply_get_drvdata(psy);
+ int regval = 0;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_ONLINE:
+ regval = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATECONT);
+ if (regval < 0)
+ return regval;
+ val->intval = !!(regval & 0x1);
+ break;
+
+ case POWER_SUPPLY_PROP_CHARGE_TYPE:
+ regval = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATE);
+ if (regval < 0)
+ return regval;
+
+ if ((regval & 0x00f0) == 0) {
+ val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
+ return 0;
+ }
+ val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
+
+ if (data->is_ltc1760) {
+ /* charge mode fast if turbo is active */
+ regval = sbsm_read_word(data->client, SBSM_CMD_LTC);
+ if (regval < 0)
+ return regval;
+ else if (regval & 0x80)
+ val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST;
+ }
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int sbsm_prop_is_writeable(struct power_supply *psy,
+ enum power_supply_property psp)
+{
+ struct sbsm_data *data = power_supply_get_drvdata(psy);
+
+ return (psp == POWER_SUPPLY_PROP_CHARGE_TYPE) && data->is_ltc1760;
+}
+
+static int sbsm_set_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ const union power_supply_propval *val)
+{
+ struct sbsm_data *data = power_supply_get_drvdata(psy);
+ int ret = -EINVAL;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_CHARGE_TYPE:
+ /* write 1 to TURBO if type fast is given */
+ if (data->is_ltc1760) {
+ u16 regval = val->intval ==
+ POWER_SUPPLY_CHARGE_TYPE_FAST ? (0x1 << 7) : 0;
+ ret = sbsm_write_word(data->client, SBSM_CMD_LTC,
+ regval);
+ }
+ break;
+
+ default:
+ break;
+ }
+
+ return ret;
+}
+
+/*
+ * Switch to battery
+ * Parameter chan is directly the content of SMB_BAT* nibble
+ */
+static int sbsm_select(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct sbsm_data *data = i2c_mux_priv(muxc);
+ int ret = 0;
+ u16 reg;
+
+ if (data->cur_chan == chan)
+ return ret;
+
+ /* chan goes from 1 ... 4 */
+ reg = 1 << (11 + chan);
+ ret = sbsm_write_word(data->client, SBSM_CMD_BATSYSSTATE, reg);
+ if (ret)
+ dev_err(&data->client->dev, "Failed to select channel %i\n",
+ chan);
+ else
+ data->cur_chan = chan;
+
+ return ret;
+}
+
+#if defined(CONFIG_OF)
+
+#include <linux/of_device.h>
+
+static const struct of_device_id sbsm_dt_ids[] = {
+ { .compatible = "sbs,sbs-manager" },
+ { .compatible = "lltc,ltc1760" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, sbsm_dt_ids);
+
+#endif
+
+static const struct power_supply_desc sbsm_default_psy_desc = {
+ .type = POWER_SUPPLY_TYPE_MAINS,
+ .properties = sbsm_props,
+ .num_properties = ARRAY_SIZE(sbsm_props),
+ .get_property = &sbsm_get_property,
+ .set_property = &sbsm_set_property,
+ .property_is_writeable = &sbsm_prop_is_writeable,
+};
+
+static int sbsm_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+ struct sbsm_data *data;
+ struct device *dev = &client->dev;
+ struct power_supply_desc *psy_desc;
+ struct power_supply_config psy_cfg = {};
+ int ret = 0, i, supported_bats;
+
+ /* Device listens only at address 0x0a */
+ if (client->addr != 0x0a)
+ return -ENODEV;
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
+ return -EPFNOSUPPORT;
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, data);
+
+ data->client = client;
+ data->is_ltc1760 = !!strstr(id->name, "ltc1760");
+
+ ret = sbsm_read_word(client, SBSM_CMD_BATSYSINFO);
+ if (ret < 0)
+ return ret;
+ supported_bats = le16_to_cpu(ret) & 0xf;
+
+ data->muxc = i2c_mux_alloc(adapter, dev, SBSM_MAX_BATS, 0,
+ I2C_MUX_LOCKED, &sbsm_select, NULL);
+ if (!data->muxc) {
+ dev_err(dev, "failed to alloc i2c mux\n");
+ ret = -ENOMEM;
+ goto err_mux_alloc;
+ }
+ data->muxc->priv = data;
+
+ /* register muxed i2c channels. One for each supported battery */
+ for (i = 0; i < SBSM_MAX_BATS; ++i) {
+ if ((1 << i) & supported_bats) {
+ ret = i2c_mux_add_adapter(data->muxc, 0, i + 1, 0);
+ if (ret) {
+ dev_err(dev,
+ "failed to register i2c mux channel %d\n",
+ i + 1);
+ goto err_mux_register;
+ }
+ }
+ }
+
+ psy_desc = devm_kmemdup(dev, &sbsm_default_psy_desc,
+ sizeof(struct power_supply_desc),
+ GFP_KERNEL);
+ if (!psy_desc) {
+ ret = -ENOMEM;
+ goto err_psy;
+ }
+
+ psy_desc->name = devm_kasprintf(dev, GFP_KERNEL, "sbsm-%s",
+ dev_name(&client->dev));
+ if (!psy_desc->name) {
+ ret = -ENOMEM;
+ goto err_psy;
+ }
+
+ psy_cfg.drv_data = data;
+ data->psy = devm_power_supply_register(dev, psy_desc, &psy_cfg);
+ if (IS_ERR(data->psy)) {
+ ret = PTR_ERR(data->psy);
+ dev_err(dev, "failed to register power supply %s\n",
+ psy_desc->name);
+ goto err_psy;
+ }
+
+ dev_info(dev, "sbsm registered\n");
+ return 0;
+
+err_psy:
+err_mux_register:
+ i2c_mux_del_adapters(data->muxc);
+
+err_mux_alloc:
+ return ret;
+}
+
+static int sbsm_remove(struct i2c_client *client)
+{
+ struct sbsm_data *data = i2c_get_clientdata(client);
+
+ i2c_mux_del_adapters(data->muxc);
+ return 0;
+}
+
+static const struct i2c_device_id sbsm_ids[] = {
+ { "sbs-manager", 0 },
+ { "ltc1760", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, sbsm_ids);
+
+static struct i2c_driver sbsm_driver = {
+ .driver = {
+ .name = "sbsm",
+ .owner = THIS_MODULE,
+ },
+ .probe = sbsm_probe,
+ .remove = sbsm_remove,
+ .id_table = sbsm_ids
+};
+module_i2c_driver(sbsm_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Karl-Heinz Schneider <karl-heinz@schneider-inet.de>");
+MODULE_DESCRIPTION("SBSM Smart Battery System Manager");