[PATCH 0/2] mcb: export FPGA information via sysfs

[PATCH 0/2] mcb: export FPGA information via sysfs

[Johannes Thumshirn]

The following series adds a way to obtain information about a MCB FPGA via
sysfs. This is viable i.e. for a field technician to check if the latest FPGA
bitstream version is applied to the hardware.

The first patch layes the foundation in order to get sysfs correctly working
with MCB and the second patch exports the bus information into sysfs.

Changes from v1:
* Address kbuild robots warning about broken bisectability

Johannes Thumshirn (2):
  mcb: Correctly initialize the bus's device
  mcb: export bus information via sysfs

 Documentation/ABI/testing/sysfs-bus-mcb | 29 ++++++++++++
 drivers/mcb/mcb-core.c                  | 79 +++++++++++++++++++++++++++++++--
 drivers/mcb/mcb-internal.h              |  1 -
 drivers/mcb/mcb-parse.c                 | 15 +++----
 include/linux/mcb.h                     | 14 ++++--
 5 files changed, 121 insertions(+), 17 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-mcb

-- 
2.7.2

[PATCH v2 1/2] mcb: Correctly initialize the bus's device

[Johannes Thumshirn]

The mcb bus' device member wasn't correctly initialized and thus wasn't placed
correctly into the driver model.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 drivers/mcb/mcb-core.c | 19 ++++++++++++++++---
 include/linux/mcb.h    |  5 ++---
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/drivers/mcb/mcb-core.c b/drivers/mcb/mcb-core.c
index a4be451..1e336cc 100644
--- a/drivers/mcb/mcb-core.c
+++ b/drivers/mcb/mcb-core.c
@@ -187,6 +187,7 @@ struct mcb_bus *mcb_alloc_bus(struct device *carrier)
 {
 	struct mcb_bus *bus;
 	int bus_nr;
+	int rc;
 
 	bus = kzalloc(sizeof(struct mcb_bus), GFP_KERNEL);
 	if (!bus)
@@ -194,14 +195,26 @@ struct mcb_bus *mcb_alloc_bus(struct device *carrier)
 
 	bus_nr = ida_simple_get(&mcb_ida, 0, 0, GFP_KERNEL);
 	if (bus_nr < 0) {
-		kfree(bus);
-		return ERR_PTR(bus_nr);
+		rc = bus_nr;
+		goto err_free;
 	}
 
-	INIT_LIST_HEAD(&bus->children);
 	bus->bus_nr = bus_nr;
 	bus->carrier = carrier;
+
+	device_initialize(&bus->dev);
+	bus->dev.parent = carrier;
+	bus->dev.bus = &mcb_bus_type;
+
+	dev_set_name(&bus->dev, "mcb:%d", bus_nr);
+	rc = device_add(&bus->dev);
+	if (rc)
+		goto err_free;
+
 	return bus;
+err_free:
+	kfree(bus);
+	return ERR_PTR(rc);
 }
 EXPORT_SYMBOL_GPL(mcb_alloc_bus);
 
diff --git a/include/linux/mcb.h b/include/linux/mcb.h
index ed06e15..3efafbc 100644
--- a/include/linux/mcb.h
+++ b/include/linux/mcb.h
@@ -21,13 +21,12 @@ struct mcb_device;
 /**
  * struct mcb_bus - MEN Chameleon Bus
  *
- * @dev: pointer to carrier device
- * @children: the child busses
+ * @dev: bus device
+ * @carrier: pointer to carrier device
  * @bus_nr: mcb bus number
  * @get_irq: callback to get IRQ number
  */
 struct mcb_bus {
-	struct list_head children;
 	struct device dev;
 	struct device *carrier;
 	int bus_nr;
-- 
2.7.2

[PATCH v2 2/2] mcb: export bus information via sysfs

[Johannes Thumshirn]

Export information about the bus stored in the FPGA's header to userspace via
sysfs, instead of hiding it in pr_debug()s from everyone.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 Documentation/ABI/testing/sysfs-bus-mcb | 29 ++++++++++++++++
 drivers/mcb/mcb-core.c                  | 60 +++++++++++++++++++++++++++++++++
 drivers/mcb/mcb-internal.h              |  1 -
 drivers/mcb/mcb-parse.c                 | 15 +++------
 include/linux/mcb.h                     |  9 +++++
 5 files changed, 103 insertions(+), 11 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-mcb

diff --git a/Documentation/ABI/testing/sysfs-bus-mcb b/Documentation/ABI/testing/sysfs-bus-mcb
new file mode 100644
index 0000000..77947c5
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-mcb
@@ -0,0 +1,29 @@
+What:		/sys/bus/mcb/devices/mcb:X
+Date:		March 2016
+KernelVersion:	4.7
+Contact:	Johannes Thumshirn <jth@kernel.org>
+Description:	Hardware chip or device hosting the MEN chameleon bus
+
+What:		/sys/bus/mcb/devices/mcb:X/revision
+Date:		March 2016
+KernelVersion:	4.7
+Contact:	Johannes Thumshirn <jth@kernel.org>
+Description:	The FPGA's revision number
+
+What:		/sys/bus/mcb/devices/mcb:X/minor
+Date:		March 2016
+KernelVersion:	4.7
+Contact:	Johannes Thumshirn <jth@kernel.org>
+Description:	The FPGA's minor number
+
+What:		/sys/bus/mcb/devices/mcb:X/model
+Date:		March 2016
+KernelVersion:	4.7
+Contact:	Johannes Thumshirn <jth@kernel.org>
+Description:	The FPGA's model number
+
+What:		/sys/bus/mcb/devices/mcb:X/name
+Date:		March 2016
+KernelVersion:	4.7
+Contact:	Johannes Thumshirn <jth@kernel.org>
+Description:	The FPGA's name
diff --git a/drivers/mcb/mcb-core.c b/drivers/mcb/mcb-core.c
index 1e336cc..9ae4d15 100644
--- a/drivers/mcb/mcb-core.c
+++ b/drivers/mcb/mcb-core.c
@@ -90,6 +90,60 @@ static void mcb_shutdown(struct device *dev)
 		mdrv->shutdown(mdev);
 }
 
+static ssize_t revision_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct mcb_bus *bus = to_mcb_bus(dev);
+
+	return scnprintf(buf, PAGE_SIZE, "%d\n", bus->revision);
+}
+static DEVICE_ATTR_RO(revision);
+
+static ssize_t model_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct mcb_bus *bus = to_mcb_bus(dev);
+
+	return scnprintf(buf, PAGE_SIZE, "%c\n", bus->model);
+}
+static DEVICE_ATTR_RO(model);
+
+static ssize_t minor_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct mcb_bus *bus = to_mcb_bus(dev);
+
+	return scnprintf(buf, PAGE_SIZE, "%d\n", bus->minor);
+}
+static DEVICE_ATTR_RO(minor);
+
+static ssize_t name_show(struct device *dev, struct device_attribute *attr,
+			 char *buf)
+{
+	struct mcb_bus *bus = to_mcb_bus(dev);
+
+	return scnprintf(buf, PAGE_SIZE, "%s\n", bus->name);
+}
+static DEVICE_ATTR_RO(name);
+
+static struct attribute *mcb_bus_attrs[] = {
+	&dev_attr_revision.attr,
+	&dev_attr_model.attr,
+	&dev_attr_minor.attr,
+	&dev_attr_name.attr,
+	NULL,
+};
+
+static const struct attribute_group mcb_carrier_group = {
+	.attrs = mcb_bus_attrs,
+};
+
+static const struct attribute_group *mcb_carrier_groups[] = {
+	&mcb_carrier_group,
+	NULL,
+};
+
+
 static struct bus_type mcb_bus_type = {
 	.name = "mcb",
 	.match = mcb_match,
@@ -99,6 +153,11 @@ static struct bus_type mcb_bus_type = {
 	.shutdown = mcb_shutdown,
 };
 
+static struct device_type mcb_carrier_device_type = {
+	.name = "mcb-carrier",
+	.groups = mcb_carrier_groups,
+};
+
 /**
  * __mcb_register_driver() - Register a @mcb_driver at the system
  * @drv: The @mcb_driver
@@ -205,6 +264,7 @@ struct mcb_bus *mcb_alloc_bus(struct device *carrier)
 	device_initialize(&bus->dev);
 	bus->dev.parent = carrier;
 	bus->dev.bus = &mcb_bus_type;
+	bus->dev.type = &mcb_carrier_device_type;
 
 	dev_set_name(&bus->dev, "mcb:%d", bus_nr);
 	rc = device_add(&bus->dev);
diff --git a/drivers/mcb/mcb-internal.h b/drivers/mcb/mcb-internal.h
index fb7493d..5254e02 100644
--- a/drivers/mcb/mcb-internal.h
+++ b/drivers/mcb/mcb-internal.h
@@ -5,7 +5,6 @@
 
 #define PCI_VENDOR_ID_MEN		0x1a88
 #define PCI_DEVICE_ID_MEN_CHAMELEON	0x4d45
-#define CHAMELEON_FILENAME_LEN		12
 #define CHAMELEONV2_MAGIC		0xabce
 #define CHAM_HEADER_SIZE		0x200
 
diff --git a/drivers/mcb/mcb-parse.c b/drivers/mcb/mcb-parse.c
index 0049269..35f385b 100644
--- a/drivers/mcb/mcb-parse.c
+++ b/drivers/mcb/mcb-parse.c
@@ -113,16 +113,11 @@ int chameleon_parse_cells(struct mcb_bus *bus, phys_addr_t mapbase,
 	}
 	p += hsize;
 
-	pr_debug("header->revision = %d\n", header->revision);
-	pr_debug("header->model = 0x%x ('%c')\n", header->model,
-		header->model);
-	pr_debug("header->minor = %d\n", header->minor);
-	pr_debug("header->bus_type = 0x%x\n", header->bus_type);
-
-
-	pr_debug("header->magic = 0x%x\n", header->magic);
-	pr_debug("header->filename = \"%.*s\"\n", CHAMELEON_FILENAME_LEN,
-		header->filename);
+	bus->revision = header->revision;
+	bus->model = header->model;
+	bus->minor = header->minor;
+	snprintf(bus->name, CHAMELEON_FILENAME_LEN + 1, "%s",
+		 header->filename);
 
 	for_each_chameleon_cell(dtype, p) {
 		switch (dtype) {
diff --git a/include/linux/mcb.h b/include/linux/mcb.h
index 3efafbc..ead13d2 100644
--- a/include/linux/mcb.h
+++ b/include/linux/mcb.h
@@ -15,6 +15,8 @@
 #include <linux/device.h>
 #include <linux/irqreturn.h>
 
+#define CHAMELEON_FILENAME_LEN 12
+
 struct mcb_driver;
 struct mcb_device;
 
@@ -25,11 +27,18 @@ struct mcb_device;
  * @carrier: pointer to carrier device
  * @bus_nr: mcb bus number
  * @get_irq: callback to get IRQ number
+ * @revision: the FPGA's revision number
+ * @model: the FPGA's model number
+ * @filename: the FPGA's name
  */
 struct mcb_bus {
 	struct device dev;
 	struct device *carrier;
 	int bus_nr;
+	u8 revision;
+	char model;
+	u8 minor;
+	char name[CHAMELEON_FILENAME_LEN + 1];
 	int (*get_irq)(struct mcb_device *dev);
 };
 #define to_mcb_bus(b) container_of((b), struct mcb_bus, dev)
-- 
2.7.2

Re: [PATCH v2 1/2] mcb: Correctly initialize the bus's device

[Andreas Werner]

On Fri, Mar 18, 2016 at 03:26:36PM +0100, Johannes Thumshirn wrote:
> The mcb bus' device member wasn't correctly initialized and thus wasn't placed
> correctly into the driver model.
> 
> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
> ---

Looks good to me. I have tested this on the MEN SC24 AMD Board
with a MCB FPGA.

Reviewed-by: Andreas Werner <andreas.werner@men.de>
Tested-by: Andreas Werner <andreas.werner@men.de>

Re: [PATCH v2 2/2] mcb: export bus information via sysfs

[Andreas Werner]

On Fri, Mar 18, 2016 at 03:26:37PM +0100, Johannes Thumshirn wrote:
> Export information about the bus stored in the FPGA's header to userspace via
> sysfs, instead of hiding it in pr_debug()s from everyone.
> 
> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
> ---

Looks good to me. I have tested this on the MEN SC24 with
a MCB FPGA.

Reviewed-by: Andreas Werner <andreas.werner@men.de>
Tested-by: Andreas Werner <andreas.werner@men.de>

Re: [PATCH v2 2/2] mcb: export bus information via sysfs

[Johannes Thumshirn]

On Freitag, 8. April 2016 09:07:15 CEST Andreas Werner wrote:
> On Fri, Mar 18, 2016 at 03:26:37PM +0100, Johannes Thumshirn wrote:
> > Export information about the bus stored in the FPGA's header to userspace
> > via sysfs, instead of hiding it in pr_debug()s from everyone.
> > 
> > Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
> > ---
> 
> Looks good to me. I have tested this on the MEN SC24 with
> a MCB FPGA.
> 
> Reviewed-by: Andreas Werner <andreas.werner@men.de>
> Tested-by: Andreas Werner <andreas.werner@men.de>

Yay, thanks

-- 
Johannes Thumshirn                                          Storage
jthumshirn@suse.de                                +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850

Re: [PATCH v2 1/2] mcb: Correctly initialize the bus's device

[Johannes Thumshirn]

On Freitag, 8. April 2016 09:06:03 CEST Andreas Werner wrote:
> On Fri, Mar 18, 2016 at 03:26:36PM +0100, Johannes Thumshirn wrote:
> > The mcb bus' device member wasn't correctly initialized and thus wasn't
> > placed correctly into the driver model.
> > 
> > Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
> > ---
> 
> Looks good to me. I have tested this on the MEN SC24 AMD Board
> with a MCB FPGA.
> 
> Reviewed-by: Andreas Werner <andreas.werner@men.de>
> Tested-by: Andreas Werner <andreas.werner@men.de>

Thanks

-- 
Johannes Thumshirn                                          Storage
jthumshirn@suse.de                                +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850