lib: Add helper for reading modparam values

Add __igt_params_get for simple reading of modparams.

v2:
 * Fix kerneldoc. (Matt)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/lib/igt_params.c b/lib/igt_params.c
index c0641698..3dad317a 100644
--- a/lib/igt_params.c
+++ b/lib/igt_params.c
@@ -156,6 +156,32 @@ int igt_params_open(int device)
 	return params;
 }
 
+/**
+ * __igt_params_get:
+ * @device: fd of the device
+ * @parameter: the name of the parameter to get
+ *
+ * This reads the value of the modparam.
+ *
+ * Returns:
+ * A nul-terminated string, must be freed by caller after use, or NULL
+ * on failure.
+ */
+char *__igt_params_get(int device, const char *parameter)
+{
+	char *str;
+	int dir;
+
+	dir = igt_params_open(device);
+	if (dir < 0)
+		return NULL;
+
+	str = igt_sysfs_get(dir, parameter);
+	close(dir);
+
+	return str;
+}
+
 __attribute__((format(printf, 3, 0)))
 static bool __igt_params_set(int device, const char *parameter,
 			     const char *fmt, va_list ap, bool save)