From: christopher.lee.bostic@gmail.com
To: openbmc@lists.ozlabs.org
Subject: [PATCH linux v5 6/7] drivers/fsi: Add FSI Bus Support for Clients
Date: Wed, 24 Aug 2016 14:54:11 -0500
Message-Id: <1472068452-32048-7-git-send-email-christopher.lee.bostic@gmail.com>
In-Reply-To: <1472068452-32048-1-git-send-email-christopher.lee.bostic@gmail.com>
References: <1472068452-32048-1-git-send-email-christopher.lee.bostic@gmail.com>
Precedence: list

From: Chris Bostic <cbostic@us.ibm.com>

Provide means for a client to register with an FSI bus and get
notifications of hot plug events.  A client is a device driver that
needs access to a physical FSI bus in order to communicate with
hardware it controls.  Utilities added to allow client to retrieve
resource information on its hardware.

Signed-off-by: Chris Bostic <cbostic@us.ibm.com>
---
 drivers/fsi/fsi.h       |  15 +++++
 drivers/fsi/fsicfam.h   |   2 +
 drivers/fsi/fsiinit.c   |   8 +++
 drivers/fsi/ldm.c       | 161 +++++++++++++++++++++++++++++++++++++++++++++++-
 drivers/fsi/readwrite.c |   4 ++
 5 files changed, 188 insertions(+), 2 deletions(-)

diff --git a/drivers/fsi/fsi.h b/drivers/fsi/fsi.h
index 67d4666..f0ed5b7 100644
--- a/drivers/fsi/fsi.h
+++ b/drivers/fsi/fsi.h
@@ -65,6 +65,10 @@ struct fsimap {
 #define FSI_DEV_PROBE_OK	9	/* Probe succeeded */
 #define FSI_DEV_PROBE_ERR	10	/* Probe failed */
 
+struct fsi_resource {
+	u32 start;			/* Start of range */
+	u32 end;			/* End of range */
+};
 
 struct fsidevice {
 	struct fsi_engine_id id;	/* Engine type/version */
@@ -91,4 +95,15 @@ struct fsidriver {
 
 #define to_fsidriver(x)	container_of((x), struct fsidriver, driver)
 
+int fsidev_register(struct fsidevice *, struct device_attribute **);
+void fsidev_unregister(struct fsidevice *);
+int fsi_get_resource(struct fsidevice *, int, struct fsi_resource *);
+char *fsidevice_name(struct fsidevice *, const char *, const char *,
+		     char *, size_t);
+int fsidevice_get_minor(struct fsidevice *);
+int fsidrv_register(struct fsidriver *);
+void fsidrv_unregister(struct fsidriver *);
+void fsi_lock_mutex(void);
+void fsi_unlock_mutex(void);
+
 #endif /* DRIVERS_FSI_H */
diff --git a/drivers/fsi/fsicfam.h b/drivers/fsi/fsicfam.h
index dde7036..8ccff5c 100644
--- a/drivers/fsi/fsicfam.h
+++ b/drivers/fsi/fsicfam.h
@@ -43,4 +43,6 @@ struct fsicfam {			/* CFAM internal structure */
 int fsi_cfamirq_request(int, struct fsicfam *);
 void fsi_cfamirq_free(struct fsicfam *);
 
+#define FSI_CFAM_SLAVEIDX	2		/* Slave engine */
+
 #endif /* DRIVERS_FSICFAM_H */
diff --git a/drivers/fsi/fsiinit.c b/drivers/fsi/fsiinit.c
index d83992e..4941062 100644
--- a/drivers/fsi/fsiinit.c
+++ b/drivers/fsi/fsiinit.c
@@ -34,6 +34,14 @@ struct fsidd fsidd = {		/* FSI device driver structure definition */
 	.major = MKDEV(FSIDD_MAJOR, 0),
 };
 
+void fsi_lock_mutex(void)
+{
+}
+
+void fsi_unlock_mutex(void)
+{
+}
+
 static int fsi_start(void)
 {
 	int rc = 0;
diff --git a/drivers/fsi/ldm.c b/drivers/fsi/ldm.c
index 9fe10b3..cb6679f 100644
--- a/drivers/fsi/ldm.c
+++ b/drivers/fsi/ldm.c
@@ -13,6 +13,48 @@
 #include <linux/blkdev.h>
 #include "fsi.h"
 #include "fsi_private.h"
+#include "fsicfam.h"
+
+/*
+ * /sys/devices/ < name > format:
+ *
+ * fsi-LL.C.EE
+ *
+ * Where:
+ * L = link, C = CFAM, E = engine
+ *
+ * TODO: expand for cascaded and hub masters
+ */
+static void myname(struct fsidevice *fsidev)
+{
+	if (dev_name(&fsidev->dev))
+		return;
+
+	dev_set_name(&fsidev->dev, "fsi-%02d.%d.%02d",
+		     fsidev->map.link, fsidev->map.cfam, fsidev->map.eng);
+}
+
+/*
+ * Unregister a FSI device with the Linux device model
+ */
+void fsidev_unregister_nolock(struct fsidevice *fsidev)
+{
+
+	dev_dbg(&fsidev->dev, "fsidev_unregister fsidev:%p\n", fsidev);
+	if (!test_and_clear_bit(FSI_DEV_ACTIVE, &fsidev->state)) {
+		dev_dbg(&fsidev->dev, "fsidev_unregister build incomplete\n");
+		return;
+	}
+	device_unregister(&fsidev->dev);
+}
+
+void fsidev_unregister(struct fsidevice *fsidev)
+{
+	fsi_lock_mutex();
+	fsidev_unregister_nolock(fsidev);
+	fsi_unlock_mutex();
+}
+EXPORT_SYMBOL(fsidev_unregister);
 
 /*
  * Register a FSI device with the Linux device model
@@ -20,15 +62,101 @@
 int fsidev_register_nolock(struct fsidevice *fsidev,
 			   struct device_attribute **ap)
 {
-	return 0;
+	int rc, slave_idx;
+
+	dev_dbg(&fsidev->dev, "register >> %d.%d.%d\n",
+		fsidev->map.link, fsidev->map.cfam, fsidev->map.eng);
+	myname(fsidev);
+
+	rc = device_register(&fsidev->dev);
+	if (rc) {
+		dev_dbg(&fsidev->dev, "register dev_register error:%d\n", rc);
+		if (fsidev->dev.release)
+			fsidev->dev.release(&fsidev->dev);
+		return rc;
+	}
+	set_bit(FSI_DEV_ACTIVE, &fsidev->state);
+	if (test_bit(FSI_DEV_PROBE_ERR, &fsidev->state)) {
+		dev_dbg(&fsidev->dev, "register dev probe error\n");
+		slave_idx = (fsidev->map.eng == FSI_CFAM_SLAVEIDX);
+		rc = slave_idx ? -ENODEV : 0;
+		fsidev_unregister_nolock(fsidev);
+		return rc;
+	}
+	dev_dbg(&fsidev->dev, "register << %d.%d.%d success\n",
+		fsidev->map.link, fsidev->map.cfam, fsidev->map.eng);
+
+	return rc;
 }
 
 int fsidev_register(struct fsidevice *fsidev, struct device_attribute **ap)
 {
-	return 0;
+	int rc;
+
+	fsi_lock_mutex();
+	rc = fsidev_register_nolock(fsidev, ap);
+	fsi_unlock_mutex();
+
+	return rc;
 }
 EXPORT_SYMBOL(fsidev_register);
 
+int fsi_get_resource(struct fsidevice *fsidev, int idx,
+		     struct fsi_resource *res)
+{
+	switch (idx) {
+	case FSI_DEV_IRQRES:
+		if (fsidev->irq_start == 0)
+			res->end = 0;
+		else
+			res->end = fsidev->irq_start + fsidev->irq_range - 1;
+		break;
+	case FSI_DEV_MEMRES:
+		res->start = fsidev->map.va;
+		res->end = res->start + fsidev->map.kb * FSI_ENGINE_SIZE - 1;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+EXPORT_SYMBOL(fsi_get_resource);
+
+/*
+ * Return the fsidevice full engine name.
+ * Name consists of:
+ * - prefix
+ * - link number
+ * - a dot '.'
+ * - cfam number
+ * - a dot '.'
+ * - engine number
+ * - postfix (client's choosing)
+ *
+ * Returns NULL if buffer space is insufficient.
+ */
+char *fsidevice_name(struct fsidevice *fsidev, const char *prefix,
+		     const char *postfix, char *buf, size_t len)
+{
+	int size;
+	struct fsimap *map = &fsidev->map;
+
+	size = snprintf(buf, len, "%sL%02dC%dE%02dP%s",
+			prefix, map->link, map->cfam, map->eng, postfix);
+
+	return (size >= len) ? NULL : buf;
+}
+EXPORT_SYMBOL(fsidevice_name);
+
+/*
+ * Retrieve minor number for the FSI device
+ */
+int fsidevice_get_minor(struct fsidevice *fsidev)
+{
+	return MINOR(fsidev->dev.devt);
+}
+EXPORT_SYMBOL(fsidevice_get_minor);
+
 /*
  * FSI bus functions.
  */
@@ -163,3 +291,32 @@ int fsibus_init(void)
 {
 	return bus_register(&fsi_bus_type);
 }
+
+/*
+ * Unregister a client FSI driver from the system
+ */
+void fsidrv_unregister(struct fsidriver *fsidrv)
+{
+	fsidrv->reset = NULL;
+	driver_unregister(&fsidrv->driver);
+}
+EXPORT_SYMBOL(fsidrv_unregister);
+
+/*
+ * Register a client FSI driver with the system
+ */
+int fsidrv_register(struct fsidriver *fsidrv)
+{
+	int rc = 0;
+
+	if (fsidrv->idlist == NULL)
+		return -EINVAL;
+	if (!fsidrv->driver.owner)
+		fsidrv->driver.owner = fsidrv->owner;
+
+	fsidrv->driver.bus = &fsi_bus_type;
+	rc = driver_register(&fsidrv->driver);
+
+	return rc;
+}
+EXPORT_SYMBOL(fsidrv_register);
diff --git a/drivers/fsi/readwrite.c b/drivers/fsi/readwrite.c
index 33d972c..3427e52 100644
--- a/drivers/fsi/readwrite.c
+++ b/drivers/fsi/readwrite.c
@@ -14,6 +14,10 @@
 #include "fsi_private.h"
 #include "fsimaster.h"
 
+/*
+ * Read/write functions to be used only by the FSI driver itself.  FSI clients
+ * will use separate interfaces
+ */
 int fsi_readw_int(struct fsimaster *master, u32 pa, u32 *value)
 {
 	return 0;
-- 
1.8.2.2