[PATCH v2 2/2] pmbus: ltc2978: add regulator gating

[atull]

From: Alan Tull <at...@opensource.altera.com>

Add regulator with support for enabling or disabling all
supplies.

Signed-off-by: Alan Tull <at...@opensource.altera.com>

v2:  Remove '#include <linux/regulator/machine.h>'
     Kconfig fixes
     Remove hardwired regulator_init_data
---
 drivers/hwmon/pmbus/Kconfig   |    7 +++++
 drivers/hwmon/pmbus/ltc2978.c |   60 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+)

diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index 6e1e493..79117b7 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -56,6 +56,13 @@ config SENSORS_LTC2978
          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 LTC2974, LTC2978, LTC3880, and LTC3883"
+       depends on SENSORS_LTC2978 && REGULATOR
+       help
+         If you say yes here you get regulator support for Linear
+         Technology LTC2974, LTC2978, LTC3880, and LTC3883.
+
 config SENSORS_MAX16064
        tristate "Maxim MAX16064"
        default n
diff --git a/drivers/hwmon/pmbus/ltc2978.c b/drivers/hwmon/pmbus/ltc2978.c
index e24ed52..2bdcfe2 100644
--- a/drivers/hwmon/pmbus/ltc2978.c
+++ b/drivers/hwmon/pmbus/ltc2978.c
@@ -20,6 +20,7 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/err.h>
+#include <linux/regulator/driver.h>
 #include <linux/slab.h>
 #include <linux/i2c.h>
 #include "pmbus.h"
@@ -151,6 +152,60 @@ static int ltc2978_read_word_data_common(struct i2c_client 
*client, int page,
        return ret;
 }
 
+#if IS_ENABLED(CONFIG_SENSORS_LTC2978_REGULATOR)
+static int ltc2978_write_pmbus_operation(struct regulator_dev *rdev, u8 value)
+{
+       struct device *dev = rdev_get_dev(rdev);
+       struct i2c_client *client = to_i2c_client(dev->parent);
+       int ret;
+
+       ret = pmbus_set_page(client, 0xff);
+       if (ret < 0)
+               return ret;
+
+       return i2c_smbus_write_byte_data(client, PMBUS_OPERATION, value);
+}
+
+static int ltc2978_enable_all(struct regulator_dev *rdev)
+{
+       return ltc2978_write_pmbus_operation(rdev, 0x80);
+}
+
+static int ltc2978_disable_all(struct regulator_dev *rdev)
+{
+       return ltc2978_write_pmbus_operation(rdev, 0);
+}
+
+static int ltc2978_is_enabled(struct regulator_dev *rdev)
+{
+       struct device *dev = rdev_get_dev(rdev);
+       struct i2c_client *client = to_i2c_client(dev->parent);
+       int ret;
+
+       ret = pmbus_set_page(client, 0xff);
+       if (ret < 0)
+               return ret;
+
+       ret = i2c_smbus_read_byte_data(client, PMBUS_OPERATION);
+       if (ret < 0)
+               return ret;
+
+       return !!(ret & 0x80);
+}
+
+static struct regulator_ops ltc2978_regulator_ops = {
+       .enable = ltc2978_enable_all,
+       .disable = ltc2978_disable_all,
+       .is_enabled = ltc2978_is_enabled,
+};
+
+static const struct regulator_desc ltc2978_reg_desc = {
+       .name = "ltc2978",
+       .ops = &ltc2978_regulator_ops,
+       .owner = THIS_MODULE,
+};
+#endif
+
 static int ltc2978_read_word_data(struct i2c_client *client, int page, int reg)
 {
        const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
@@ -487,6 +542,11 @@ static int ltc2978_probe(struct i2c_client *client,
        default:
                return -ENODEV;
        }
+
+#if IS_ENABLED(CONFIG_SENSORS_LTC2978_REGULATOR)
+       info->reg_desc = &ltc2978_reg_desc;
+#endif
+
        return pmbus_do_probe(client, id, info);
 }
 
-- 
1.7.9.5

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