[RFC PATCH linux 6/9] hwmon: occ: Add hwmon implementation for the P8 OCC

[Andrew Jeffery]

Signed-off-by: Andrew Jeffery <andrew at aj.id.au>
---
 drivers/hwmon/occ/Kconfig      |  14 +++++
 drivers/hwmon/occ/Makefile     |   1 +
 drivers/hwmon/occ/occ_p8_i2c.c | 133 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 148 insertions(+)
 create mode 100644 drivers/hwmon/occ/occ_p8_i2c.c

diff --git a/drivers/hwmon/occ/Kconfig b/drivers/hwmon/occ/Kconfig
index cdb64a71af6e..085e1f370c42 100644
--- a/drivers/hwmon/occ/Kconfig
+++ b/drivers/hwmon/occ/Kconfig
@@ -13,3 +13,17 @@ menuconfig SENSORS_PPC_OCC
 
 	  This driver can also be built as a module. If so, the module
 	  will be called occ.
+
+if SENSORS_PPC_OCC
+
+config SENSORS_PPC_OCC_P8_I2C
+	tristate "POWER8 OCC hwmon support"
+	depends on I2C
+	help
+	  Provide a hwmon sysfs interface for the POWER8 On-Chip Controller,
+	  exposing temperature, frequency and power measurements.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called occ-p8-i2c.
+
+endif
diff --git a/drivers/hwmon/occ/Makefile b/drivers/hwmon/occ/Makefile
index a6881f93067c..05a84e987127 100644
--- a/drivers/hwmon/occ/Makefile
+++ b/drivers/hwmon/occ/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_SENSORS_PPC_OCC) += occ.o occ_sysfs.o
+obj-$(CONFIG_SENSORS_PPC_OCC_P8_I2C) += occ_scom_i2c.o occ_p8.o occ_p8_i2c.o
diff --git a/drivers/hwmon/occ/occ_p8_i2c.c b/drivers/hwmon/occ/occ_p8_i2c.c
new file mode 100644
index 000000000000..1b66f302fe16
--- /dev/null
+++ b/drivers/hwmon/occ/occ_p8_i2c.c
@@ -0,0 +1,133 @@
+/*
+ * occ_p8_i2c.c - hwmon OCC driver
+ *
+ * This file contains the i2c layer for accessing the OCC over i2c bus.
+ *
+ * Copyright 2016 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+
+#include "scom.h"
+#include "occ_scom_i2c.h"
+#include "occ_p8.h"
+#include "occ_sysfs.h"
+
+#define OCC_I2C_NAME	"occ-p8-i2c"
+
+static char *caps_sensor_names[] = {
+	"curr_powercap",
+	"curr_powerreading",
+	"norm_powercap",
+	"max_powercap",
+	"min_powercap",
+	"user_powerlimit"
+};
+
+int p8_i2c_getscom(void *bus, u32 address, u8 *data, size_t offset)
+{
+	/* P8 i2c slave requires address to be shifted by 1 */
+	address = address << 1;
+
+	return occ_i2c_getscom(bus, address, data, offset);
+}
+
+int p8_i2c_putscom(void *bus, u32 address, u32 data0, u32 data1)
+{
+	/* P8 i2c slave requires address to be shifted by 1 */
+	address = address << 1;
+
+	return occ_i2c_putscom(bus, address, data0, data1);
+}
+
+static struct occ_bus_ops p8_bus_ops = {
+	.getscom = p8_i2c_getscom,
+	.putscom = p8_i2c_putscom,
+};
+
+static struct occ_sysfs_config p8_sysfs_config = {
+	.num_caps_fields = ARRAY_SIZE(caps_sensor_names),
+	.caps_names = caps_sensor_names,
+};
+
+static int occ_p8_probe(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct occ *occ;
+	struct occ_sysfs *hwmon;
+
+	occ = occ_p8_start(&client->dev, client, p8_bus_ops);
+	if (IS_ERR(occ))
+		return PTR_ERR(occ);
+
+	hwmon = occ_sysfs_start(&client->dev, occ, &p8_sysfs_config);
+	if (IS_ERR(hwmon))
+		return PTR_ERR(hwmon);
+
+	i2c_set_clientdata(client, hwmon);
+
+	return 0;
+}
+
+static int occ_p8_remove(struct i2c_client *client)
+{
+	return occ_p8_stop(i2c_get_clientdata(client));
+}
+
+/* used by old-style board info. */
+static const struct i2c_device_id occ_ids[] = {
+	{ OCC_I2C_NAME, 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, occ_ids);
+
+/* used by device table */
+static const struct of_device_id occ_of_match[] = {
+	{ .compatible = "ibm,occ-p8-i2c" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, occ_of_match);
+
+/*
+ * i2c-core uses i2c-detect() to detect device in below address list.
+ * If exists, address will be assigned to client.
+ * It is also possible to read address from device table.
+ */
+static const unsigned short normal_i2c[] = {0x50, 0x51, I2C_CLIENT_END };
+
+static struct i2c_driver occ_p8_driver = {
+	.class = I2C_CLASS_HWMON,
+	.driver = {
+		.name = OCC_I2C_NAME,
+		.pm = NULL,
+		.of_match_table = occ_of_match,
+	},
+	.probe = occ_p8_probe,
+	.remove = occ_p8_remove,
+	.id_table = occ_ids,
+	.address_list = normal_i2c,
+};
+
+module_i2c_driver(occ_p8_driver);
+
+MODULE_AUTHOR("Eddie James <eajames at us.ibm.com>");
+MODULE_DESCRIPTION("BMC P8 OCC hwmon driver");
+MODULE_LICENSE("GPL");
-- 
2.9.3