4 files changed, 195 insertions, 3 deletions

diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index 6e1e4935fc62..a674cd83a4e2 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -47,15 +47,22 @@ config SENSORS_LM25066
 	  be called lm25066.
 
 config SENSORS_LTC2978
-	tristate "Linear Technologies LTC2974, LTC2978, LTC3880, and LTC3883"
+	tristate "Linear Technologies LTC2978 and compatibles"
 	default n
 	help
 	  If you say yes here you get hardware monitoring support for Linear
-	  Technology LTC2974, LTC2978, LTC3880, and LTC3883.
+	  Technology LTC2974, LTC2977, LTC2978, LTC3880, LTC3883, and LTM4676.
 
 	  This driver can also be built as a module. If so, the module will
 	  be called ltc2978.
 
+config SENSORS_LTC2978_REGULATOR
+	boolean "Regulator support for LTC2978 and compatibles"
+	depends on SENSORS_LTC2978 && REGULATOR
+	help
+	  If you say yes here you get regulator support for Linear
+	  Technology LTC2974, LTC2977, LTC2978, LTC3880, LTC3883, and LTM4676.
+
 config SENSORS_MAX16064
 	tristate "Maxim MAX16064"
 	default n
diff --git a/drivers/hwmon/pmbus/ltc2978.c b/drivers/hwmon/pmbus/ltc2978.c
index e24ed521051a..0835050ec245 100644
--- a/drivers/hwmon/pmbus/ltc2978.c
+++ b/drivers/hwmon/pmbus/ltc2978.c
@@ -22,6 +22,7 @@
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/i2c.h>
+#include <linux/regulator/driver.h>
 #include "pmbus.h"
 
 enum chips { ltc2974, ltc2977, ltc2978, ltc3880, ltc3883, ltm4676 };
@@ -374,6 +375,19 @@ static const struct i2c_device_id ltc2978_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, ltc2978_id);
 
+#if IS_ENABLED(CONFIG_SENSORS_LTC2978_REGULATOR)
+static const struct regulator_desc ltc2978_reg_desc[] = {
+	PMBUS_REGULATOR("vout", 0),
+	PMBUS_REGULATOR("vout", 1),
+	PMBUS_REGULATOR("vout", 2),
+	PMBUS_REGULATOR("vout", 3),
+	PMBUS_REGULATOR("vout", 4),
+	PMBUS_REGULATOR("vout", 5),
+	PMBUS_REGULATOR("vout", 6),
+	PMBUS_REGULATOR("vout", 7),
+};
+#endif /* CONFIG_SENSORS_LTC2978_REGULATOR */
+
 static int ltc2978_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
@@ -487,13 +501,36 @@ static int ltc2978_probe(struct i2c_client *client,
 	default:
 		return -ENODEV;
 	}
+
+#if IS_ENABLED(CONFIG_SENSORS_LTC2978_REGULATOR)
+	info->num_regulators = info->pages;
+	info->reg_desc = ltc2978_reg_desc;
+	if (info->num_regulators > ARRAY_SIZE(ltc2978_reg_desc)) {
+		dev_err(&client->dev, "num_regulators too large!");
+		info->num_regulators = ARRAY_SIZE(ltc2978_reg_desc);
+	}
+#endif
+
 	return pmbus_do_probe(client, id, info);
 }
 
-/* This is the driver that will be inserted */
+#ifdef CONFIG_OF
+static const struct of_device_id ltc2978_of_match[] = {
+	{ .compatible = "lltc,ltc2974" },
+	{ .compatible = "lltc,ltc2977" },
+	{ .compatible = "lltc,ltc2978" },
+	{ .compatible = "lltc,ltc3880" },
+	{ .compatible = "lltc,ltc3883" },
+	{ .compatible = "lltc,ltm4676" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ltc2978_of_match);
+#endif
+
 static struct i2c_driver ltc2978_driver = {
 	.driver = {
 		   .name = "ltc2978",
+		   .of_match_table = of_match_ptr(ltc2978_of_match),
 		   },
 	.probe = ltc2978_probe,
 	.remove = pmbus_do_remove,
diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index fa9beb3eb60c..89a23ff836e7 100644
--- a/drivers/hwmon/pmbus/pmbus.h
+++ b/drivers/hwmon/pmbus/pmbus.h
@@ -19,6 +19,8 @@
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include <linux/regulator/driver.h>
+
 #ifndef PMBUS_H
 #define PMBUS_H
 
@@ -186,6 +188,11 @@
 #define PMBUS_VIRT_STATUS_VMON		(PMBUS_VIRT_BASE + 35)
 
 /*
+ * OPERATION
+ */
+#define PB_OPERATION_CONTROL_ON		(1<<7)
+
+/*
  * CAPABILITY
  */
 #define PB_CAPABILITY_SMBALERT		(1<<4)
@@ -365,8 +372,27 @@ struct pmbus_driver_info {
 	 */
 	int (*identify)(struct i2c_client *client,
 			struct pmbus_driver_info *info);
+
+	/* Regulator functionality, if supported by this chip driver. */
+	int num_regulators;
+	const struct regulator_desc *reg_desc;
 };
 
+/* Regulator ops */
+
+extern struct regulator_ops pmbus_regulator_ops;
+
+/* Macro for filling in array of struct regulator_desc */
+#define PMBUS_REGULATOR(_name, _id)				\
+	[_id] = {						\
+		.name = (_name # _id),				\
+		.id = (_id),					\
+		.of_match = of_match_ptr(_name # _id),		\
+		.regulators_node = of_match_ptr("regulators"),	\
+		.ops = &pmbus_regulator_ops,			\
+		.owner = THIS_MODULE,				\
+	}
+
 /* Function declarations */
 
 void pmbus_clear_cache(struct i2c_client *client);
@@ -375,6 +401,10 @@ int pmbus_read_word_data(struct i2c_client *client, u8 page, u8 reg);
 int pmbus_write_word_data(struct i2c_client *client, u8 page, u8 reg, u16 word);
 int pmbus_read_byte_data(struct i2c_client *client, int page, u8 reg);
 int pmbus_write_byte(struct i2c_client *client, int page, u8 value);
+int pmbus_write_byte_data(struct i2c_client *client, int page, u8 reg,
+			  u8 value);
+int pmbus_update_byte_data(struct i2c_client *client, int page, u8 reg,
+			   u8 mask, u8 value);
 void pmbus_clear_faults(struct i2c_client *client);
 bool pmbus_check_byte_register(struct i2c_client *client, int page, int reg);
 bool pmbus_check_word_register(struct i2c_client *client, int page, int reg);
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 291d11fe93e7..f2e47c7dd808 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -29,6 +29,8 @@
 #include <linux/hwmon-sysfs.h>
 #include <linux/jiffies.h>
 #include <linux/i2c/pmbus.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
 #include "pmbus.h"
 
 /*
@@ -253,6 +255,37 @@ int pmbus_read_byte_data(struct i2c_client *client, int page, u8 reg)
 }
 EXPORT_SYMBOL_GPL(pmbus_read_byte_data);
 
+int pmbus_write_byte_data(struct i2c_client *client, int page, u8 reg, u8 value)
+{
+	int rv;
+
+	rv = pmbus_set_page(client, page);
+	if (rv < 0)
+		return rv;
+
+	return i2c_smbus_write_byte_data(client, reg, value);
+}
+EXPORT_SYMBOL_GPL(pmbus_write_byte_data);
+
+int pmbus_update_byte_data(struct i2c_client *client, int page, u8 reg,
+			   u8 mask, u8 value)
+{
+	unsigned int tmp;
+	int rv;
+
+	rv = pmbus_read_byte_data(client, page, reg);
+	if (rv < 0)
+		return rv;
+
+	tmp = (rv & ~mask) | (value & mask);
+
+	if (tmp != rv)
+		rv = pmbus_write_byte_data(client, page, reg, tmp);
+
+	return rv;
+}
+EXPORT_SYMBOL_GPL(pmbus_update_byte_data);
+
 /*
  * _pmbus_read_byte_data() is similar to pmbus_read_byte_data(), but checks if
  * a device specific mapping function exists and calls it if necessary.
@@ -1727,6 +1760,84 @@ static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data,
 	return 0;
 }
 
+#if IS_ENABLED(CONFIG_REGULATOR)
+static int pmbus_regulator_is_enabled(struct regulator_dev *rdev)
+{
+	struct device *dev = rdev_get_dev(rdev);
+	struct i2c_client *client = to_i2c_client(dev->parent);
+	u8 page = rdev_get_id(rdev);
+	int ret;
+
+	ret = pmbus_read_byte_data(client, page, PMBUS_OPERATION);
+	if (ret < 0)
+		return ret;
+
+	return !!(ret & PB_OPERATION_CONTROL_ON);
+}
+
+static int _pmbus_regulator_on_off(struct regulator_dev *rdev, bool enable)
+{
+	struct device *dev = rdev_get_dev(rdev);
+	struct i2c_client *client = to_i2c_client(dev->parent);
+	u8 page = rdev_get_id(rdev);
+
+	return pmbus_update_byte_data(client, page, PMBUS_OPERATION,
+				      PB_OPERATION_CONTROL_ON,
+				      enable ? PB_OPERATION_CONTROL_ON : 0);
+}
+
+static int pmbus_regulator_enable(struct regulator_dev *rdev)
+{
+	return _pmbus_regulator_on_off(rdev, 1);
+}
+
+static int pmbus_regulator_disable(struct regulator_dev *rdev)
+{
+	return _pmbus_regulator_on_off(rdev, 0);
+}
+
+struct regulator_ops pmbus_regulator_ops = {
+	.enable = pmbus_regulator_enable,
+	.disable = pmbus_regulator_disable,
+	.is_enabled = pmbus_regulator_is_enabled,
+};
+EXPORT_SYMBOL_GPL(pmbus_regulator_ops);
+
+static int pmbus_regulator_register(struct pmbus_data *data)
+{
+	struct device *dev = data->dev;
+	const struct pmbus_driver_info *info = data->info;
+	const struct pmbus_platform_data *pdata = dev_get_platdata(dev);
+	struct regulator_dev *rdev;
+	int i;
+
+	for (i = 0; i < info->num_regulators; i++) {
+		struct regulator_config config = { };
+
+		config.dev = dev;
+		config.driver_data = data;
+
+		if (pdata && pdata->reg_init_data)
+			config.init_data = &pdata->reg_init_data[i];
+
+		rdev = devm_regulator_register(dev, &info->reg_desc[i],
+					       &config);
+		if (IS_ERR(rdev)) {
+			dev_err(dev, "Failed to register %s regulator\n",
+				info->reg_desc[i].name);
+			return PTR_ERR(rdev);
+		}
+	}
+
+	return 0;
+}
+#else
+static int pmbus_regulator_register(struct pmbus_data *data)
+{
+	return 0;
+}
+#endif
+
 int pmbus_do_probe(struct i2c_client *client, const struct i2c_device_id *id,
 		   struct pmbus_driver_info *info)
 {
@@ -1781,8 +1892,15 @@ int pmbus_do_probe(struct i2c_client *client, const struct i2c_device_id *id,
 		dev_err(dev, "Failed to register hwmon device\n");
 		goto out_kfree;
 	}
+
+	ret = pmbus_regulator_register(data);
+	if (ret)
+		goto out_unregister;
+
 	return 0;
 
+out_unregister:
+	hwmon_device_unregister(data->hwmon_dev);
 out_kfree:
 	kfree(data->group.attrs);
 	return ret;