[RFC PATCH linux 4/9] hwmon: occ: Add I2C SCOM transport implementation

[Andrew Jeffery]

The BMC queries the OCC on POWER8 chips with SCOMs over I2C.

Signed-off-by: Andrew Jeffery <andrew at aj.id.au>
---
 drivers/hwmon/occ/occ_scom_i2c.c | 68 ++++++++++++++++++++++++++++++++++++++++
 drivers/hwmon/occ/occ_scom_i2c.h | 20 ++++++++++++
 2 files changed, 88 insertions(+)
 create mode 100644 drivers/hwmon/occ/occ_scom_i2c.c
 create mode 100644 drivers/hwmon/occ/occ_scom_i2c.h

diff --git a/drivers/hwmon/occ/occ_scom_i2c.c b/drivers/hwmon/occ/occ_scom_i2c.c
new file mode 100644
index 000000000000..b1a060331c4a
--- /dev/null
+++ b/drivers/hwmon/occ/occ_scom_i2c.c
@@ -0,0 +1,68 @@
+/*
+ * occ_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/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include "scom.h"
+#include "occ_scom_i2c.h"
+
+#define OCC_I2C_NAME	"occ-p8-i2c"
+
+int occ_i2c_getscom(void *bus, u32 address, u8 *data, size_t offset)
+{
+	ssize_t rc;
+	u64 buf;
+	struct i2c_client *client = bus;
+
+	rc = i2c_master_send(client, (const char *)&address, sizeof(u32));
+	if (rc != sizeof(u32))
+		return -SCOM_WRITE_ERROR;
+
+	rc = i2c_master_recv(client, (char *)&buf, sizeof(u64));
+	if (rc != sizeof(u64))
+		return -SCOM_READ_ERROR;
+
+	*((u64 *)&data[offset]) = be64_to_cpu(buf);
+
+	return 0;
+}
+EXPORT_SYMBOL(occ_i2c_getscom);
+
+int occ_i2c_putscom(void *bus, u32 address, u32 data0, u32 data1)
+{
+	u32 buf[3];
+	ssize_t rc;
+	struct i2c_client *client = bus;
+
+	buf[0] = address;
+	buf[1] = data1;
+	buf[2] = data0;
+
+	rc = i2c_master_send(client, (const char *)buf, sizeof(u32) * 3);
+	if (rc != sizeof(u32) * 3)
+		return -SCOM_WRITE_ERROR;
+
+	return 0;
+}
+EXPORT_SYMBOL(occ_i2c_putscom);
+
+MODULE_AUTHOR("Eddie James <eajames at us.ibm.com>");
+MODULE_DESCRIPTION("I2C OCC SCOM transport");
+MODULE_LICENSE("GPL");
diff --git a/drivers/hwmon/occ/occ_scom_i2c.h b/drivers/hwmon/occ/occ_scom_i2c.h
new file mode 100644
index 000000000000..92225f4cd584
--- /dev/null
+++ b/drivers/hwmon/occ/occ_scom_i2c.h
@@ -0,0 +1,20 @@
+/*
+ * occ_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.
+ */
+
+int occ_i2c_getscom(void *bus, u32 address, u8 *data, size_t offset);
+int occ_i2c_putscom(void *bus, u32 address, u32 data0, u32 data1);
-- 
2.9.3