[PATCH v2 2/4] dfl: add dfl bus support to MODULE_DEVICE_TABLE()

[Xu Yilun <yilun.xu@intel.com>]

Device Feature List (DFL) is a linked list of feature headers within the
device MMIO space. It is used by FPGA to enumerate multiple sub features
within it. Each feature can be uniquely identified by DFL type and
feature id, which can be read out from feature headers.

A dfl bus helps DFL framework modularize DFL device drivers for different
sub features. The dfl bus matches its devices and drivers by DFL type and
feature id.

This patch add dfl bus support to MODULE_DEVICE_TABLE() by adding info
about struct dfl_device_id in devicetable-offsets.c and add a dfl entry
point in file2alias.c.

Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Acked-by: Wu Hao <hao.wu@intel.com>
---
v2: add comments for the format of modalias
---
 scripts/mod/devicetable-offsets.c |  4 ++++
 scripts/mod/file2alias.c          | 17 +++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/scripts/mod/devicetable-offsets.c b/scripts/mod/devicetable-offsets.c
index 27007c1..d8350ee 100644
--- a/scripts/mod/devicetable-offsets.c
+++ b/scripts/mod/devicetable-offsets.c
@@ -243,5 +243,9 @@ int main(void)
 	DEVID(mhi_device_id);
 	DEVID_FIELD(mhi_device_id, chan);
 
+	DEVID(dfl_device_id);
+	DEVID_FIELD(dfl_device_id, type);
+	DEVID_FIELD(dfl_device_id, feature_id);
+
 	return 0;
 }
diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c
index 2417dd1..9fd2e60 100644
--- a/scripts/mod/file2alias.c
+++ b/scripts/mod/file2alias.c
@@ -1368,6 +1368,22 @@ static int do_mhi_entry(const char *filename, void *symval, char *alias)
 	return 1;
 }
 
+/* Looks like: dfl:tNfN */
+static int do_dfl_entry(const char *filename, void *symval, char *alias)
+{
+	DEF_FIELD(symval, dfl_device_id, type);
+	DEF_FIELD(symval, dfl_device_id, feature_id);
+
+	/*
+	 * type contains 4 valid bits and feature_id contains 12 valid bits
+	 * according to DFL specification.
+	 */
+	sprintf(alias, "dfl:t%01Xf%03X", type, feature_id);
+
+	add_wildcard(alias);
+	return 1;
+}
+
 /* Does namelen bytes of name exactly match the symbol? */
 static bool sym_is(const char *name, unsigned namelen, const char *symbol)
 {
@@ -1442,6 +1458,7 @@ static const struct devtable devtable[] = {
 	{"tee", SIZE_tee_client_device_id, do_tee_entry},
 	{"wmi", SIZE_wmi_device_id, do_wmi_entry},
 	{"mhi", SIZE_mhi_device_id, do_mhi_entry},
+	{"dfl", SIZE_dfl_device_id, do_dfl_entry},
 };
 
 /* Create MODULE_ALIAS() statements.
-- 
2.7.4