Merge branch 'i2c/sbs-manager' into i2c/for-4.15

11 files changed, 598 insertions, 145 deletions

diff --git a/drivers/i2c/busses/i2c-parport-light.c b/drivers/i2c/busses/i2c-parport-light.c
index faa8fb8f2b8f..fa41ff799533 100644
--- a/drivers/i2c/busses/i2c-parport-light.c
+++ b/drivers/i2c/busses/i2c-parport-light.c
@@ -123,7 +123,6 @@ static struct i2c_adapter parport_adapter = {
 
 /* SMBus alert support */
 static struct i2c_smbus_alert_setup alert_data = {
-	.alert_edge_triggered	= 1,
 };
 static struct i2c_client *ara;
 static struct lineop parport_ctrl_irq = {
diff --git a/drivers/i2c/busses/i2c-parport.c b/drivers/i2c/busses/i2c-parport.c
index a8e54df4aed6..319209a07353 100644
--- a/drivers/i2c/busses/i2c-parport.c
+++ b/drivers/i2c/busses/i2c-parport.c
@@ -237,7 +237,6 @@ static void i2c_parport_attach(struct parport *port)
 
 	/* Setup SMBus alert if supported */
 	if (adapter_parm[type].smbus_alert) {
-		adapter->alert_data.alert_edge_triggered = 1;
 		adapter->ara = i2c_setup_smbus_alert(&adapter->adapter,
 						     &adapter->alert_data);
 		if (adapter->ara)
diff --git a/drivers/i2c/busses/i2c-thunderx-pcidrv.c b/drivers/i2c/busses/i2c-thunderx-pcidrv.c
index df0976f4432a..1a7cad874756 100644
--- a/drivers/i2c/busses/i2c-thunderx-pcidrv.c
+++ b/drivers/i2c/busses/i2c-thunderx-pcidrv.c
@@ -118,8 +118,6 @@ static void thunder_i2c_clock_disable(struct device *dev, struct clk *clk)
 static int thunder_i2c_smbus_setup_of(struct octeon_i2c *i2c,
 				      struct device_node *node)
 {
-	u32 type;
-
 	if (!node)
 		return -EINVAL;
 
@@ -127,10 +125,6 @@ static int thunder_i2c_smbus_setup_of(struct octeon_i2c *i2c,
 	if (!i2c->alert_data.irq)
 		return -EINVAL;
 
-	type = irqd_get_trigger_type(irq_get_irq_data(i2c->alert_data.irq));
-	i2c->alert_data.alert_edge_triggered =
-		(type & IRQ_TYPE_LEVEL_MASK) ? 1 : 0;
-
 	i2c->ara = i2c_setup_smbus_alert(&i2c->adap, &i2c->alert_data);
 	if (!i2c->ara)
 		return -ENODEV;
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index db6558e5f657..7b08f3446bfc 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -29,6 +29,7 @@
 #include <linux/errno.h>
 #include <linux/gpio.h>
 #include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
 #include <linux/idr.h>
 #include <linux/init.h>
 #include <linux/irqflags.h>
@@ -1269,6 +1270,10 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 		goto out_list;
 	}
 
+	res = of_i2c_setup_smbus_alert(adap);
+	if (res)
+		goto out_reg;
+
 	dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
 
 	pm_runtime_no_callbacks(&adap->dev);
@@ -1300,6 +1305,10 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
 
 	return 0;
 
+out_reg:
+	init_completion(&adap->dev_released);
+	device_unregister(&adap->dev);
+	wait_for_completion(&adap->dev_released);
 out_list:
 	mutex_lock(&core_lock);
 	idr_remove(&i2c_adapter_idr, adap->nr);
diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c
index 10f00a82ec9d..4bb9927afd01 100644
--- a/drivers/i2c/i2c-core-smbus.c
+++ b/drivers/i2c/i2c-core-smbus.c
@@ -17,6 +17,7 @@
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/smbus.h>
@@ -592,3 +593,57 @@ s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client,
 	return i;
 }
 EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data_or_emulated);
+
+/**
+ * i2c_setup_smbus_alert - Setup SMBus alert support
+ * @adapter: the target adapter
+ * @setup: setup data for the SMBus alert handler
+ * Context: can sleep
+ *
+ * Setup handling of the SMBus alert protocol on a given I2C bus segment.
+ *
+ * Handling can be done either through our IRQ handler, or by the
+ * adapter (from its handler, periodic polling, or whatever).
+ *
+ * NOTE that if we manage the IRQ, we *MUST* know if it's level or
+ * edge triggered in order to hand it to the workqueue correctly.
+ * If triggering the alert seems to wedge the system, you probably
+ * should have said it's level triggered.
+ *
+ * This returns the ara client, which should be saved for later use with
+ * i2c_handle_smbus_alert() and ultimately i2c_unregister_device(); or NULL
+ * to indicate an error.
+ */
+struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
+					 struct i2c_smbus_alert_setup *setup)
+{
+	struct i2c_board_info ara_board_info = {
+		I2C_BOARD_INFO("smbus_alert", 0x0c),
+		.platform_data = setup,
+	};
+
+	return i2c_new_device(adapter, &ara_board_info);
+}
+EXPORT_SYMBOL_GPL(i2c_setup_smbus_alert);
+
+#if IS_ENABLED(CONFIG_I2C_SMBUS) && IS_ENABLED(CONFIG_OF)
+int of_i2c_setup_smbus_alert(struct i2c_adapter *adapter)
+{
+	struct i2c_client *client;
+	int irq;
+
+	irq = of_property_match_string(adapter->dev.of_node, "interrupt-names",
+				       "smbus_alert");
+	if (irq == -EINVAL || irq == -ENODATA)
+		return 0;
+	else if (irq < 0)
+		return irq;
+
+	client = i2c_setup_smbus_alert(adapter, NULL);
+	if (!client)
+		return -ENODEV;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_i2c_setup_smbus_alert);
+#endif
diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c
index f9271c713d20..5a1dd7f13bac 100644
--- a/drivers/i2c/i2c-smbus.c
+++ b/drivers/i2c/i2c-smbus.c
@@ -21,12 +21,11 @@
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/of_irq.h>
 #include <linux/slab.h>
 #include <linux/workqueue.h>
 
 struct i2c_smbus_alert {
-	unsigned int		alert_edge_triggered:1;
-	int			irq;
 	struct work_struct	alert;
 	struct i2c_client	*ara;		/* Alert response address */
 };
@@ -72,13 +71,12 @@ static int smbus_do_alert(struct device *dev, void *addrp)
  * The alert IRQ handler needs to hand work off to a task which can issue
  * SMBus calls, because those sleeping calls can't be made in IRQ context.
  */
-static void smbus_alert(struct work_struct *work)
+static irqreturn_t smbus_alert(int irq, void *d)
 {
-	struct i2c_smbus_alert *alert;
+	struct i2c_smbus_alert *alert = d;
 	struct i2c_client *ara;
 	unsigned short prev_addr = 0;	/* Not a valid address */
 
-	alert = container_of(work, struct i2c_smbus_alert, alert);
 	ara = alert->ara;
 
 	for (;;) {
@@ -115,21 +113,17 @@ static void smbus_alert(struct work_struct *work)
 		prev_addr = data.addr;
 	}
 
-	/* We handled all alerts; re-enable level-triggered IRQs */
-	if (!alert->alert_edge_triggered)
-		enable_irq(alert->irq);
+	return IRQ_HANDLED;
 }
 
-static irqreturn_t smbalert_irq(int irq, void *d)
+static void smbalert_work(struct work_struct *work)
 {
-	struct i2c_smbus_alert *alert = d;
+	struct i2c_smbus_alert *alert;
 
-	/* Disable level-triggered IRQs until we handle them */
-	if (!alert->alert_edge_triggered)
-		disable_irq_nosync(irq);
+	alert = container_of(work, struct i2c_smbus_alert, alert);
+
+	smbus_alert(0, alert);
 
-	schedule_work(&alert->alert);
-	return IRQ_HANDLED;
 }
 
 /* Setup SMBALERT# infrastructure */
@@ -139,28 +133,35 @@ static int smbalert_probe(struct i2c_client *ara,
 	struct i2c_smbus_alert_setup *setup = dev_get_platdata(&ara->dev);
 	struct i2c_smbus_alert *alert;
 	struct i2c_adapter *adapter = ara->adapter;
-	int res;
+	int res, irq;
 
 	alert = devm_kzalloc(&ara->dev, sizeof(struct i2c_smbus_alert),
 			     GFP_KERNEL);
 	if (!alert)
 		return -ENOMEM;
 
-	alert->alert_edge_triggered = setup->alert_edge_triggered;
-	alert->irq = setup->irq;
-	INIT_WORK(&alert->alert, smbus_alert);
+	if (setup) {
+		irq = setup->irq;
+	} else {
+		irq = of_irq_get_byname(adapter->dev.of_node, "smbus_alert");
+		if (irq <= 0)
+			return irq;
+	}
+
+	INIT_WORK(&alert->alert, smbalert_work);
 	alert->ara = ara;
 
-	if (setup->irq > 0) {
-		res = devm_request_irq(&ara->dev, setup->irq, smbalert_irq,
-				       0, "smbus_alert", alert);
+	if (irq > 0) {
+		res = devm_request_threaded_irq(&ara->dev, irq,
+						NULL, smbus_alert,
+						IRQF_SHARED | IRQF_ONESHOT,
+						"smbus_alert", alert);
 		if (res)
 			return res;
 	}
 
 	i2c_set_clientdata(ara, alert);
-	dev_info(&adapter->dev, "supports SMBALERT#, %s trigger\n",
-		 setup->alert_edge_triggered ? "edge" : "level");
+	dev_info(&adapter->dev, "supports SMBALERT#\n");
 
 	return 0;
 }
@@ -190,38 +191,6 @@ static struct i2c_driver smbalert_driver = {
 };
 
 /**
- * i2c_setup_smbus_alert - Setup SMBus alert support
- * @adapter: the target adapter
- * @setup: setup data for the SMBus alert handler
- * Context: can sleep
- *
- * Setup handling of the SMBus alert protocol on a given I2C bus segment.
- *
- * Handling can be done either through our IRQ handler, or by the
- * adapter (from its handler, periodic polling, or whatever).
- *
- * NOTE that if we manage the IRQ, we *MUST* know if it's level or
- * edge triggered in order to hand it to the workqueue correctly.
- * If triggering the alert seems to wedge the system, you probably
- * should have said it's level triggered.
- *
- * This returns the ara client, which should be saved for later use with
- * i2c_handle_smbus_alert() and ultimately i2c_unregister_device(); or NULL
- * to indicate an error.
- */
-struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
-					 struct i2c_smbus_alert_setup *setup)
-{
-	struct i2c_board_info ara_board_info = {
-		I2C_BOARD_INFO("smbus_alert", 0x0c),
-		.platform_data = setup,
-	};
-
-	return i2c_new_device(adapter, &ara_board_info);
-}
-EXPORT_SYMBOL_GPL(i2c_setup_smbus_alert);
-
-/**
  * i2c_handle_smbus_alert - Handle an SMBus alert
  * @ara: the ARA client on the relevant adapter
  * Context: can't sleep
diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c
index 7b992db38021..2ca068d8b92d 100644
--- a/drivers/i2c/muxes/i2c-mux-pca954x.c
+++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
@@ -246,36 +246,6 @@ static irqreturn_t pca954x_irq_handler(int irq, void *dev_id)
 	return handled ? IRQ_HANDLED : IRQ_NONE;
 }
 
-static void pca954x_irq_mask(struct irq_data *idata)
-{
-	struct pca954x *data = irq_data_get_irq_chip_data(idata);
-	unsigned int pos = idata->hwirq;
-	unsigned long flags;
-
-	raw_spin_lock_irqsave(&data->lock, flags);
-
-	data->irq_mask &= ~BIT(pos);
-	if (!data->irq_mask)
-		disable_irq(data->client->irq);
-
-	raw_spin_unlock_irqrestore(&data->lock, flags);
-}
-
-static void pca954x_irq_unmask(struct irq_data *idata)
-{
-	struct pca954x *data = irq_data_get_irq_chip_data(idata);
-	unsigned int pos = idata->hwirq;
-	unsigned long flags;
-
-	raw_spin_lock_irqsave(&data->lock, flags);
-
-	if (!data->irq_mask)
-		enable_irq(data->client->irq);
-	data->irq_mask |= BIT(pos);
-
-	raw_spin_unlock_irqrestore(&data->lock, flags);
-}
-
 static int pca954x_irq_set_type(struct irq_data *idata, unsigned int type)
 {
 	if ((type & IRQ_TYPE_SENSE_MASK) != IRQ_TYPE_LEVEL_LOW)
@@ -285,8 +255,6 @@ static int pca954x_irq_set_type(struct irq_data *idata, unsigned int type)
 
 static struct irq_chip pca954x_irq_chip = {
 	.name = "i2c-mux-pca954x",
-	.irq_mask = pca954x_irq_mask,
-	.irq_unmask = pca954x_irq_unmask,
 	.irq_set_type = pca954x_irq_set_type,
 };
 
@@ -294,7 +262,7 @@ static int pca954x_irq_setup(struct i2c_mux_core *muxc)
 {
 	struct pca954x *data = i2c_mux_priv(muxc);
 	struct i2c_client *client = data->client;
-	int c, err, irq;
+	int c, irq;
 
 	if (!data->chip->has_irq || client->irq <= 0)
 		return 0;
@@ -309,29 +277,31 @@ static int pca954x_irq_setup(struct i2c_mux_core *muxc)
 
 	for (c = 0; c < data->chip->nchans; c++) {
 		irq = irq_create_mapping(data->irq, c);
+		if (!irq) {
+			dev_err(&client->dev, "failed irq create map\n");
+			return -EINVAL;
+		}
 		irq_set_chip_data(irq, data);
 		irq_set_chip_and_handler(irq, &pca954x_irq_chip,
 			handle_simple_irq);
 	}
 
-	err = devm_request_threaded_irq(&client->dev, data->client->irq, NULL,
-					pca954x_irq_handler,
-					IRQF_ONESHOT | IRQF_SHARED,
-					"pca954x", data);
-	if (err)
-		goto err_req_irq;
+	return 0;
+}
 
-	disable_irq(data->client->irq);
+static void pca954x_cleanup(struct i2c_mux_core *muxc)
+{
+	struct pca954x *data = i2c_mux_priv(muxc);
+	int c, irq;
 
-	return 0;
-err_req_irq:
-	for (c = 0; c < data->chip->nchans; c++) {
-		irq = irq_find_mapping(data->irq, c);
-		irq_dispose_mapping(irq);
+	if (data->irq) {
+		for (c = 0; c < data->chip->nchans; c++) {
+			irq = irq_find_mapping(data->irq, c);
+			irq_dispose_mapping(irq);
+		}
+		irq_domain_remove(data->irq);
 	}
-	irq_domain_remove(data->irq);
-
-	return err;
+	i2c_mux_del_adapters(muxc);
 }
 
 /*
@@ -391,7 +361,7 @@ static int pca954x_probe(struct i2c_client *client,
 
 	ret = pca954x_irq_setup(muxc);
 	if (ret)
-		goto fail_del_adapters;
+		goto fail_cleanup;
 
 	/* Now create an adapter for each channel */
 	for (num = 0; num < data->chip->nchans; num++) {
@@ -414,7 +384,16 @@ static int pca954x_probe(struct i2c_client *client,
 
 		ret = i2c_mux_add_adapter(muxc, force, num, class);
 		if (ret)
-			goto fail_del_adapters;
+			goto fail_cleanup;
+	}
+
+	if (data->irq) {
+		ret = devm_request_threaded_irq(&client->dev, data->client->irq,
+						NULL, pca954x_irq_handler,
+						IRQF_ONESHOT | IRQF_SHARED,
+						"pca954x", data);
+		if (ret)
+			goto fail_cleanup;
 	}
 
 	dev_info(&client->dev,
@@ -424,26 +403,16 @@ static int pca954x_probe(struct i2c_client *client,
 
 	return 0;
 
-fail_del_adapters:
-	i2c_mux_del_adapters(muxc);
+fail_cleanup:
+	pca954x_cleanup(muxc);
 	return ret;
 }
 
 static int pca954x_remove(struct i2c_client *client)
 {
 	struct i2c_mux_core *muxc = i2c_get_clientdata(client);
-	struct pca954x *data = i2c_mux_priv(muxc);
-	int c, irq;
 
-	if (data->irq) {
-		for (c = 0; c < data->chip->nchans; c++) {
-			irq = irq_find_mapping(data->irq, c);
-			irq_dispose_mapping(irq);
-		}
-		irq_domain_remove(data->irq);
-	}
-
-	i2c_mux_del_adapters(muxc);
+	pca954x_cleanup(muxc);
 	return 0;
 }
 
diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index 5ab90c1f3f7c..fbca0ba7fc52 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -184,6 +184,20 @@ config CHARGER_SBS
         help
 	  Say Y to include support for SBS compilant battery chargers.
 
+config MANAGER_SBS
+	tristate "Smart Battery System Manager"
+	depends on I2C && I2C_MUX && GPIOLIB
+	select I2C_SMBUS
+	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_BQ27XXX
 	tristate "BQ27xxx battery driver"
 	help
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index 621a19058fec..3e8f49a17770 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_BATTERY_IPAQ_MICRO) += ipaq_micro_battery.o
 obj-$(CONFIG_BATTERY_WM97XX)	+= wm97xx_battery.o
 obj-$(CONFIG_BATTERY_SBS)	+= sbs-battery.o
 obj-$(CONFIG_CHARGER_SBS)	+= sbs-charger.o
+obj-$(CONFIG_MANAGER_SBS)	+= sbs-manager.o
 obj-$(CONFIG_BATTERY_BQ27XXX)	+= bq27xxx_battery.o
 obj-$(CONFIG_BATTERY_BQ27XXX_I2C) += bq27xxx_battery_i2c.o
 obj-$(CONFIG_BATTERY_BQ27XXX_HDQ) += bq27xxx_battery_hdq.o
diff --git a/drivers/power/supply/sbs-battery.c b/drivers/power/supply/sbs-battery.c
index b19a73176910..83d7b4115857 100644
--- a/drivers/power/supply/sbs-battery.c
+++ b/drivers/power/supply/sbs-battery.c
@@ -177,10 +177,8 @@ static bool force_load;
 static int sbs_read_word_data(struct i2c_client *client, u8 address)
 {
 	struct sbs_info *chip = i2c_get_clientdata(client);
+	int retries = chip->i2c_retry_count;
 	s32 ret = 0;
-	int retries = 1;
-
-	retries = chip->i2c_retry_count;
 
 	while (retries > 0) {
 		ret = i2c_smbus_read_word_data(client, address);
@@ -204,7 +202,7 @@ static int sbs_read_string_data(struct i2c_client *client, u8 address,
 {
 	struct sbs_info *chip = i2c_get_clientdata(client);
 	s32 ret = 0, block_length = 0;
-	int retries_length = 1, retries_block = 1;
+	int retries_length, retries_block;
 	u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
 
 	retries_length = chip->i2c_retry_count;
@@ -269,10 +267,8 @@ static int sbs_write_word_data(struct i2c_client *client, u8 address,
 	u16 value)
 {
 	struct sbs_info *chip = i2c_get_clientdata(client);
+	int retries = chip->i2c_retry_count;
 	s32 ret = 0;
-	int retries = 1;
-
-	retries = chip->i2c_retry_count;
 
 	while (retries > 0) {
 		ret = i2c_smbus_write_word_data(client, address, value);
@@ -321,16 +317,6 @@ static int sbs_get_battery_presence_and_health(
 	union power_supply_propval *val)
 {
 	s32 ret;
-	struct sbs_info *chip = i2c_get_clientdata(client);
-
-	if (psp == POWER_SUPPLY_PROP_PRESENT && chip->gpio_detect) {
-		ret = gpiod_get_value_cansleep(chip->gpio_detect);
-		if (ret < 0)
-			return ret;
-		val->intval = ret;
-		chip->is_present = val->intval;
-		return ret;
-	}
 
 	/*
 	 * Write to ManufacturerAccess with ManufacturerAccess command
@@ -570,7 +556,7 @@ static int sbs_get_battery_serial_number(struct i2c_client *client,
 	if (ret < 0)
 		return ret;
 
-	ret = sprintf(sbs_serial, "%04x", ret);
+	sprintf(sbs_serial, "%04x", ret);
 	val->strval = sbs_serial;
 
 	return 0;
@@ -598,6 +584,19 @@ static int sbs_get_property(struct power_supply *psy,
 	struct sbs_info *chip = power_supply_get_drvdata(psy);
 	struct i2c_client *client = chip->client;
 
+	if (chip->gpio_detect) {
+		ret = gpiod_get_value_cansleep(chip->gpio_detect);
+		if (ret < 0)
+			return ret;
+		if (psp == POWER_SUPPLY_PROP_PRESENT) {
+			val->intval = ret;
+			chip->is_present = val->intval;
+			return 0;
+		}
+		if (ret == 0)
+			return -ENODATA;
+	}
+
 	switch (psp) {
 	case POWER_SUPPLY_PROP_PRESENT:
 	case POWER_SUPPLY_PROP_HEALTH:
diff --git a/drivers/power/supply/sbs-manager.c b/drivers/power/supply/sbs-manager.c
new file mode 100644
index 000000000000..ccb4217b9638
--- /dev/null
+++ b/drivers/power/supply/sbs-manager.c
@@ -0,0 +1,445 @@
+/*
+ * 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/gpio.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/power_supply.h>
+#include <linux/property.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
+
+#define SBSM_MASK_BAT_SUPPORTED  GENMASK(3, 0)
+#define SBSM_MASK_CHARGE_BAT     GENMASK(7, 4)
+#define SBSM_BIT_AC_PRESENT      BIT(0)
+#define SBSM_BIT_TURBO           BIT(7)
+
+#define SBSM_SMB_BAT_OFFSET      11
+struct sbsm_data {
+	struct i2c_client *client;
+	struct i2c_mux_core *muxc;
+
+	struct power_supply *psy;
+
+	u8 cur_chan;          /* currently selected channel */
+	struct gpio_chip chip;
+	bool is_ltc1760;      /* special capabilities */
+
+	unsigned int supported_bats;
+	unsigned int last_state;
+	unsigned int last_state_cont;
+};
+
+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;
+
+	for (retries = SBSM_RETRY_CNT; retries > 0; retries--) {
+		reg = i2c_smbus_read_word_data(client, address);
+		if (reg >= 0)
+			break;
+	}
+
+	if (reg < 0) {
+		dev_err(&client->dev, "failed to read register 0x%02x\n",
+			address);
+	}
+
+	return reg;
+}
+
+static int sbsm_write_word(struct i2c_client *client, u8 address, u16 word)
+{
+	int ret, retries;
+
+	for (retries = SBSM_RETRY_CNT; retries > 0; retries--) {
+		ret = i2c_smbus_write_word_data(client, address, word);
+		if (ret >= 0)
+			break;
+	}
+	if (ret < 0)
+		dev_err(&client->dev, "failed to write to register 0x%02x\n",
+			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 & SBSM_BIT_AC_PRESENT);
+		break;
+
+	case POWER_SUPPLY_PROP_CHARGE_TYPE:
+		regval = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATE);
+		if (regval < 0)
+			return regval;
+
+		if ((regval & SBSM_MASK_CHARGE_BAT) == 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 & SBSM_BIT_TURBO)
+				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;
+	u16 regval;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CHARGE_TYPE:
+		/* write 1 to TURBO if type fast is given */
+		if (!data->is_ltc1760)
+			break;
+		regval = val->intval ==
+			 POWER_SUPPLY_CHARGE_TYPE_FAST ? SBSM_BIT_TURBO : 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);
+	struct device *dev = &data->client->dev;
+	int ret = 0;
+	u16 reg;
+
+	if (data->cur_chan == chan)
+		return ret;
+
+	/* chan goes from 1 ... 4 */
+	reg = 1 << BIT(SBSM_SMB_BAT_OFFSET + chan);
+	ret = sbsm_write_word(data->client, SBSM_CMD_BATSYSSTATE, reg);
+	if (ret)
+		dev_err(dev, "Failed to select channel %i\n", chan);
+	else
+		data->cur_chan = chan;
+
+	return ret;
+}
+
+static int sbsm_gpio_get_value(struct gpio_chip *gc, unsigned int off)
+{
+	struct sbsm_data *data = gpiochip_get_data(gc);
+	int ret;
+
+	ret = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATE);
+	if (ret < 0)
+		return ret;
+
+	return ret & BIT(off);
+}
+
+/*
+ * This needs to be defined or the GPIO lib fails to register the pin.
+ * But the 'gpio' is always an input.
+ */
+static int sbsm_gpio_direction_input(struct gpio_chip *gc, unsigned int off)
+{
+	return 0;
+}
+
+static int sbsm_do_alert(struct device *dev, void *d)
+{
+	struct i2c_client *client = i2c_verify_client(dev);
+	struct i2c_driver *driver;
+
+	if (!client || client->addr != 0x0b)
+		return 0;
+
+	device_lock(dev);
+	if (client->dev.driver) {
+		driver = to_i2c_driver(client->dev.driver);
+		if (driver->alert)
+			driver->alert(client, I2C_PROTOCOL_SMBUS_ALERT, 0);
+		else
+			dev_warn(&client->dev, "no driver alert()!\n");
+	} else {
+		dev_dbg(&client->dev, "alert with no driver\n");
+	}
+	device_unlock(dev);
+
+	return -EBUSY;
+}
+
+static void sbsm_alert(struct i2c_client *client, enum i2c_alert_protocol prot,
+		       unsigned int d)
+{
+	struct sbsm_data *sbsm = i2c_get_clientdata(client);
+
+	int ret, i, irq_bat = 0, state = 0;
+
+	ret = sbsm_read_word(sbsm->client, SBSM_CMD_BATSYSSTATE);
+	if (ret >= 0) {
+		irq_bat = ret ^ sbsm->last_state;
+		sbsm->last_state = ret;
+		state = ret;
+	}
+
+	ret = sbsm_read_word(sbsm->client, SBSM_CMD_BATSYSSTATECONT);
+	if ((ret >= 0) &&
+	    ((ret ^ sbsm->last_state_cont) & SBSM_BIT_AC_PRESENT)) {
+		irq_bat |= sbsm->supported_bats & state;
+		power_supply_changed(sbsm->psy);
+	}
+	sbsm->last_state_cont = ret;
+
+	for (i = 0; i < SBSM_MAX_BATS; i++) {
+		if (irq_bat & BIT(i)) {
+			device_for_each_child(&sbsm->muxc->adapter[i]->dev,
+					      NULL, sbsm_do_alert);
+		}
+	}
+}
+
+static int sbsm_gpio_setup(struct sbsm_data *data)
+{
+	struct gpio_chip *gc = &data->chip;
+	struct i2c_client *client = data->client;
+	struct device *dev = &client->dev;
+	int ret;
+
+	if (!device_property_present(dev, "gpio-controller"))
+		return 0;
+
+	ret  = sbsm_read_word(client, SBSM_CMD_BATSYSSTATE);
+	if (ret < 0)
+		return ret;
+	data->last_state = ret;
+
+	ret  = sbsm_read_word(client, SBSM_CMD_BATSYSSTATECONT);
+	if (ret < 0)
+		return ret;
+	data->last_state_cont = ret;
+
+	gc->get = sbsm_gpio_get_value;
+	gc->direction_input  = sbsm_gpio_direction_input;
+	gc->can_sleep = true;
+	gc->base = -1;
+	gc->ngpio = SBSM_MAX_BATS;
+	gc->label = client->name;
+	gc->parent = dev;
+	gc->owner = THIS_MODULE;
+
+	ret = devm_gpiochip_add_data(dev, gc, data);
+	if (ret) {
+		dev_err(dev, "devm_gpiochip_add_data failed: %d\n", ret);
+		return ret;
+	}
+
+	return ret;
+}
+
+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;
+
+	/* Device listens only at address 0x0a */
+	if (client->addr != 0x0a)
+		return -EINVAL;
+
+	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;
+	data->supported_bats = ret & SBSM_MASK_BAT_SUPPORTED;
+	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 (data->supported_bats & BIT(i)) {
+			ret = i2c_mux_add_adapter(data->muxc, 0, i + 1, 0);
+			if (ret)
+				break;
+		}
+	}
+	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;
+	}
+	ret = sbsm_gpio_setup(data);
+	if (ret < 0)
+		goto err_psy;
+
+	psy_cfg.drv_data = data;
+	psy_cfg.of_node = dev->of_node;
+	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;
+	}
+
+	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);
+
+#ifdef CONFIG_OF
+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 struct i2c_driver sbsm_driver = {
+	.driver = {
+		.name = "sbsm",
+		.of_match_table = of_match_ptr(sbsm_dt_ids),
+	},
+	.probe		= sbsm_probe,
+	.remove		= sbsm_remove,
+	.alert		= sbsm_alert,
+	.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");