[PATCH v2 1/2] hwmon: pmbus: Add Infineon PXE1610 VR driver

[Vijay Khemka]

Added pmbus driver for the new device Infineon pxe1610
voltage regulator. It also supports similar family device
PXE1110 and PXM1310.

Signed-off-by: Vijay Khemka <vijaykhemka at fb.com>
---
Changes in v2:
incorporated all the feedback from Guenter Roeck <linux at roeck-us.net>

 drivers/hwmon/pmbus/Kconfig   |   9 +++
 drivers/hwmon/pmbus/Makefile  |   1 +
 drivers/hwmon/pmbus/pxe1610.c | 139 ++++++++++++++++++++++++++++++++++
 3 files changed, 149 insertions(+)
 create mode 100644 drivers/hwmon/pmbus/pxe1610.c

diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index 30751eb9550a..338ef9b5a395 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -154,6 +154,15 @@ config SENSORS_MAX8688
 	  This driver can also be built as a module. If so, the module will
 	  be called max8688.
 
+config SENSORS_PXE1610
+	tristate "Infineon PXE1610"
+	help
+	  If you say yes here you get hardware monitoring support for Infineon
+	  PXE1610.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called pxe1610.
+
 config SENSORS_TPS40422
 	tristate "TI TPS40422"
 	help
diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
index 2219b9300316..b0fbd017a91a 100644
--- a/drivers/hwmon/pmbus/Makefile
+++ b/drivers/hwmon/pmbus/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_SENSORS_MAX20751)	+= max20751.o
 obj-$(CONFIG_SENSORS_MAX31785)	+= max31785.o
 obj-$(CONFIG_SENSORS_MAX34440)	+= max34440.o
 obj-$(CONFIG_SENSORS_MAX8688)	+= max8688.o
+obj-$(CONFIG_SENSORS_PXE1610)	+= pxe1610.o
 obj-$(CONFIG_SENSORS_TPS40422)	+= tps40422.o
 obj-$(CONFIG_SENSORS_TPS53679)	+= tps53679.o
 obj-$(CONFIG_SENSORS_UCD9000)	+= ucd9000.o
diff --git a/drivers/hwmon/pmbus/pxe1610.c b/drivers/hwmon/pmbus/pxe1610.c
new file mode 100644
index 000000000000..ebe3f023f840
--- /dev/null
+++ b/drivers/hwmon/pmbus/pxe1610.c
@@ -0,0 +1,139 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Hardware monitoring driver for Infineon PXE1610
+ *
+ * Copyright (c) 2019 Facebook Inc
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include "pmbus.h"
+
+#define PXE1610_NUM_PAGES 3
+
+/* Identify chip parameters. */
+static int pxe1610_identify(struct i2c_client *client,
+			     struct pmbus_driver_info *info)
+{
+	if (pmbus_check_byte_register(client, 0, PMBUS_VOUT_MODE)) {
+		u8 vout_mode;
+		int ret;
+
+		/* Read the register with VOUT scaling value.*/
+		ret = pmbus_read_byte_data(client, 0, PMBUS_VOUT_MODE);
+		if (ret < 0)
+			return ret;
+
+		vout_mode = ret & GENMASK(4, 0);
+
+		switch (vout_mode) {
+		case 1:
+			info->vrm_version = vr12;
+			break;
+		case 2:
+			info->vrm_version = vr13;
+			break;
+		default:
+			return -ENODEV;
+		}
+	}
+
+	return 0;
+}
+
+static struct pmbus_driver_info pxe1610_info = {
+	.pages = PXE1610_NUM_PAGES,
+	.format[PSC_VOLTAGE_IN] = linear,
+	.format[PSC_VOLTAGE_OUT] = vid,
+	.format[PSC_CURRENT_IN] = linear,
+	.format[PSC_CURRENT_OUT] = linear,
+	.format[PSC_TEMPERATURE] = linear,
+	.format[PSC_POWER] = linear,
+	.func[0] = PMBUS_HAVE_VIN
+		| PMBUS_HAVE_VOUT | PMBUS_HAVE_IIN
+		| PMBUS_HAVE_IOUT | PMBUS_HAVE_PIN
+		| PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
+		| PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT
+		| PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
+	.func[1] = PMBUS_HAVE_VIN
+		| PMBUS_HAVE_VOUT | PMBUS_HAVE_IIN
+		| PMBUS_HAVE_IOUT | PMBUS_HAVE_PIN
+		| PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
+		| PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT
+		| PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
+	.func[2] = PMBUS_HAVE_VIN
+		| PMBUS_HAVE_VOUT | PMBUS_HAVE_IIN
+		| PMBUS_HAVE_IOUT | PMBUS_HAVE_PIN
+		| PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP
+		| PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT
+		| PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
+	.identify = pxe1610_identify,
+};
+
+static int pxe1610_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
+{
+	struct pmbus_driver_info *info;
+	u8 buf[I2C_SMBUS_BLOCK_MAX];
+	int ret;
+
+	if (!i2c_check_functionality(
+			client->adapter,
+			I2C_FUNC_SMBUS_READ_BYTE_DATA
+			| I2C_FUNC_SMBUS_READ_WORD_DATA
+			| I2C_FUNC_SMBUS_READ_BLOCK_DATA))
+		return -ENODEV;
+
+	/*
+	 * By default this device doesn't boot to page 0, so set page 0
+	 * to access all pmbus registers.
+	 */
+	i2c_smbus_write_byte_data(client, PMBUS_PAGE, 0);
+
+	/* Read Manufacturer id */
+	ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
+	if (ret < 0) {
+		dev_err(&client->dev, "Failed to read PMBUS_MFR_ID\n");
+		return ret;
+	}
+	if (ret != 2 || strncmp(buf, "XP", 2)) {
+		dev_err(&client->dev, "MFR_ID unrecognized\n");
+		return -ENODEV;
+	}
+
+	info = devm_kmemdup(&client->dev, &pxe1610_info,
+			    sizeof(struct pmbus_driver_info),
+			    GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	return pmbus_do_probe(client, id, info);
+}
+
+static const struct i2c_device_id pxe1610_id[] = {
+	{"pxe1610", 0},
+	{"pxe1110", 0},
+	{"pxm1310", 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(i2c, pxe1610_id);
+
+static struct i2c_driver pxe1610_driver = {
+	.driver = {
+			.name = "pxe1610",
+			},
+	.probe = pxe1610_probe,
+	.remove = pmbus_do_remove,
+	.id_table = pxe1610_id,
+};
+
+module_i2c_driver(pxe1610_driver);
+
+MODULE_AUTHOR("Vijay Khemka <vijaykhemka at fb.com>");
+MODULE_DESCRIPTION("PMBus driver for Infineon PXE1610, PXE1110 and PXM1310");
+MODULE_LICENSE("GPL");
-- 
2.17.1