[PATCH 2/4] fpga mgr: Expose FPGA capabilities to userland via sysfs

Moritz Fischer
2016-11-07T00:14:39Z

Expose FPGA capabilities to userland via sysfs.

Add Documentation for currently supported capabilities
that get exported via sysfs.

Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com>
Cc: Alan Tull <atull@opensource.altera.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Sören Brinkmann <soren.brinkmann@xilinx.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
---
Documentation/ABI/testing/sysfs-class-fpga-manager | 16 ++++++++++++++++
drivers/fpga/fpga-mgr.c | 20 ++++++++++++++++++++
include/linux/fpga/fpga-mgr.h | 2 ++
3 files changed, 38 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-class-fpga-manager b/Documentation/ABI/testing/sysfs-class-fpga-manager
index 23056c5..d9aee21 100644
--- a/Documentation/ABI/testing/sysfs-class-fpga-manager
+++ b/Documentation/ABI/testing/sysfs-class-fpga-manager
@@ -35,3 +35,19 @@ Description: Read fpga manager state as a string.
* write complete = Doing post programming steps
* write complete error = Error while doing post programming
* operating = FPGA is programmed and operating
+
+What: /sys/class/fpga_manager/fpga/capabilities
+Date: November 2016
+KernelVersion: 4.9
+Contact: Moritz Fischer <moritz.fischer@ettus.com>
+Description: Read fpga manager capabilities as a string.
+ The intent is to provide userspace with information on what
+ operations the particular instance can execute.
+
+ Each line expresses a capability that is available on the
+ particular instance of an fpga manager.
+ Supported so far:
+
+ * Full reconfiguration
+ * Partial reconfiguration
+ * Decrypt bitstream on the fly
diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
index ed57c17..98230b7 100644
--- a/drivers/fpga/fpga-mgr.c
+++ b/drivers/fpga/fpga-mgr.c
@@ -167,6 +167,11 @@ static const char * const state_str[] = {
[FPGA_MGR_STATE_OPERATING] = "operating",
};

+static const char * const cap_str[] = {
+ [FPGA_MGR_CAP_FULL_RECONF] = "Full reconfiguration",
+ [FPGA_MGR_CAP_PARTIAL_RECONF] = "Partial reconfiguration",
+};
+
static ssize_t name_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -183,10 +188,25 @@ static ssize_t state_show(struct device *dev,
return sprintf(buf, "%s\n", state_str[mgr->state]);
}

+static ssize_t capabilities_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct fpga_manager *mgr = to_fpga_manager(dev);
+ char *start = buf;
+ enum fpga_mgr_capability cap;
+
+ for_each_fpga_mgr_cap_mask(cap, mgr->caps)
+ buf += sprintf(buf, "%s\n", cap_str[cap]);
+
+ return buf - start;
+}
+
+static DEVICE_ATTR_RO(capabilities);
static DEVICE_ATTR_RO(name);
static DEVICE_ATTR_RO(state);

static struct attribute *fpga_mgr_attrs[] = {
+ &dev_attr_capabilities.attr,
&dev_attr_name.attr,
&dev_attr_state.attr,
NULL,
diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
index e73429c..9bb96a5 100644
--- a/include/linux/fpga/fpga-mgr.h
+++ b/include/linux/fpga/fpga-mgr.h
@@ -108,6 +108,8 @@ static inline void __fpga_mgr_cap_set(enum fpga_mgr_capability cap,
set_bit(cap, mask->bits);
}

+#define for_each_fpga_mgr_cap_mask(cap, mask) \
+ for_each_set_bit(cap, mask.bits, FPGA_MGR_CAP_END)

/**
* struct fpga_manager_ops - ops for low level fpga manager drivers
--
2.10.0