[PATCH linux dev-4.7 1/5] drivers/fsi: Add MFSI a.k.a. hub master device driver

[Christopher Bostic]

Add the basic hub master device driver.  Registers with the
FSI core to be notified of its engine device and its link devices.

Signed-off-by: Christopher Bostic <cbostic at linux.vnet.ibm.com>
---
 drivers/fsi/Kconfig          |  9 ++++++
 drivers/fsi/Makefile         |  1 +
 drivers/fsi/fsi-master-hub.c | 65 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 75 insertions(+)
 create mode 100644 drivers/fsi/fsi-master-hub.c

diff --git a/drivers/fsi/Kconfig b/drivers/fsi/Kconfig
index c78b9b6e..bb7c5d5 100644
--- a/drivers/fsi/Kconfig
+++ b/drivers/fsi/Kconfig
@@ -18,6 +18,15 @@ config FSI_MASTER_GPIO
 	---help---
 	This option enables a FSI master driver using GPIO lines.
 
+config FSI_MASTER_HUB
+	tristate "Hub FSI master"
+	depends on FSI
+	---help---
+	This option enables a hub FSI master. Hub masters extend the
+	address space of the primary master and allow chaining of
+	multiple devices. Chaining FSI links from one hub to another
+	allows for very high device fan out.
+
 config FSI_SCOM
 	tristate "SCOM FSI client device driver"
 	depends on FSI
diff --git a/drivers/fsi/Makefile b/drivers/fsi/Makefile
index 3a106ba..37b5f5e 100644
--- a/drivers/fsi/Makefile
+++ b/drivers/fsi/Makefile
@@ -3,3 +3,4 @@ obj-$(CONFIG_FSI) += fsi-core.o
 obj-$(CONFIG_FSI_MASTER_GPIO) += fsi-master-gpio.o
 obj-$(CONFIG_FSI_SCOM) += fsi-scom.o
 obj-$(CONFIG_FSI_I2C) += i2c/
+obj-$(CONFIG_FSI_MASTER_HUB) += fsi-master-hub.o
diff --git a/drivers/fsi/fsi-master-hub.c b/drivers/fsi/fsi-master-hub.c
new file mode 100644
index 0000000..19b7c77
--- /dev/null
+++ b/drivers/fsi/fsi-master-hub.c
@@ -0,0 +1,65 @@
+/*
+ * Hub Master FSI Client device driver
+ *
+ * Copyright (C) IBM Corporation 2017
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERGCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/fsi.h>
+#include <linux/module.h>
+#include <linux/cdev.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+
+#include "fsi-master.h"
+
+#define FSI_ENGID_HUB_MASTER	0x1C
+#define FSI_ENGID_HUB_LINK	0x1D
+
+static int hub_master_probe(struct device *dev)
+{
+	return 0;
+}
+
+static struct fsi_device_id hub_master_ids[] = {
+	{
+		.engine_type = FSI_ENGID_HUB_MASTER,
+		.version = FSI_VERSION_ANY,
+	},
+	{
+		.engine_type = FSI_ENGID_HUB_LINK,
+		.version = FSI_VERSION_ANY,
+	},
+	{ 0 }
+};
+
+static struct fsi_driver hub_master_drv = {
+	.id_table = hub_master_ids,
+	.drv = {
+		.name = "hub_master",
+		.bus = &fsi_bus_type,
+		.probe = hub_master_probe,
+	}
+};
+
+static int hub_master_init(void)
+{
+	return fsi_driver_register(&hub_master_drv);
+}
+
+static void hub_master_exit(void)
+{
+	fsi_driver_unregister(&hub_master_drv);
+}
+
+module_init(hub_master_init);
+module_exit(hub_master_exit);
+MODULE_LICENSE("GPL");
-- 
1.8.2.2