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

From: Johannes Thumshirn
Date: Fri Mar 18 2016 - 09:50:30 EST


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@xxxxxxx>
Tested-by: Andreas Werner <andreas.werner@xxxxxx>
---
Documentation/ABI/testing/sysfs-bus-mcb | 29 ++++++++++++++++
drivers/mcb/mcb-core.c | 59 +++++++++++++++++++++++++++++++++
drivers/mcb/mcb-internal.h | 1 -
drivers/mcb/mcb-parse.c | 15 +++------
include/linux/mcb.h | 9 +++++
5 files changed, 102 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@xxxxxxxxxx>
+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@xxxxxxxxxx>
+Description: The FPGA's revision number
+
+What: /sys/bus/mcb/devices/mcb:X/minor
+Date: March 2016
+KernelVersion: 4.7
+Contact: Johannes Thumshirn <jth@xxxxxxxxxx>
+Description: The FPGA's minor number
+
+What: /sys/bus/mcb/devices/mcb:X/model
+Date: March 2016
+KernelVersion: 4.7
+Contact: Johannes Thumshirn <jth@xxxxxxxxxx>
+Description: The FPGA's model number
+
+What: /sys/bus/mcb/devices/mcb:X/name
+Date: March 2016
+KernelVersion: 4.7
+Contact: Johannes Thumshirn <jth@xxxxxxxxxx>
+Description: The FPGA's name
diff --git a/drivers/mcb/mcb-core.c b/drivers/mcb/mcb-core.c
index 2633a6b..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
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