Merge branch 'i2c/for-4.15' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:
 "This contains two bigger than usual tree-wide changes this time. They
  all have proper acks, caused no merge conflicts in linux-next where
  they have been for a while. They are namely:

   - to-gpiod conversion of the i2c-gpio driver and its users (touching
     arch/* and drivers/mfd/*)

   - adding a sbs-manager based on I2C core updates to SMBus alerts
     (touching drivers/power/*)

  Other notable changes:

   - i2c_boardinfo can now carry a dev_name to be used when the device
     is created. This is because some devices in ACPI world need fixed
     names to find the regulators.

   - the designware driver got a long discussed overhaul of its PM
     handling. img-scb and davinci got PM support, too.

   - at24 driver has way better OF support. And it has a new maintainer.
     Thanks Bartosz for stepping up!

  The rest is regular driver updates and fixes"

* 'i2c/for-4.15' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (55 commits)
  ARM: sa1100: simpad: Correct I2C GPIO offsets
  i2c: aspeed: Deassert reset in probe
  eeprom: at24: Add OF device ID table
  MAINTAINERS: new maintainer for AT24 driver
  i2c: nuc900: remove platform_data, too
  i2c: thunderx: Remove duplicate NULL check
  i2c: taos-evm: Remove duplicate NULL check
  i2c: Make i2c_unregister_device() NULL-aware
  i2c: xgene-slimpro: Support v2
  i2c: mpc: remove useless variable initialization
  i2c: omap: Trigger bus recovery in lockup case
  i2c: gpio: Add support for named gpios in DT
  dt-bindings: i2c: i2c-gpio: Add support for named gpios
  i2c: gpio: Local vars in probe
  i2c: gpio: Augment all boardfiles to use open drain
  i2c: gpio: Enforce open drain through gpiolib
  gpio: Make it possible for consumers to enforce open drain
  i2c: gpio: Convert to use descriptors
  power: supply: sbs-message: fix some code style issues
  power: supply: sbs-battery: remove unchecked return var
  ...

4 files changed, 477 insertions, 18 deletions

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 aae4e4a8bbb3..e83aa843bcc6 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -37,6 +37,7 @@ 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");