[PATCH 6.6 07/14] thunderbolt: Make is_gen4_link() available to the rest of the driver

From: Alexandru Gagniuc
Date: Tue Oct 01 2024 - 13:34:13 EST


From: Gil Fine <gil.fine@xxxxxxxxxxxxxxx>

[ Upstream commit aa673d606078da36ebc379f041c794228ac08cb5 ]

Rework the function to return the link generation, update the name to
tb_port_get_link_generation(), and make available to the rest of the
driver. This is needed in the subsequent patches.

Signed-off-by: Gil Fine <gil.fine@xxxxxxxxxxxxxxx>
Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Signed-off-by: Qin Wan <qin.wan@xxxxxx>
Signed-off-by: Alexandru Gagniuc <alexandru.gagniuc@xxxxxx>
---
drivers/thunderbolt/switch.c | 36 +++++++++++++++++++++++++++++-------
drivers/thunderbolt/tb.h | 1 +
2 files changed, 30 insertions(+), 7 deletions(-)

diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index f9f40c0e9add..c7f16fd0a043 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -921,6 +921,32 @@ int tb_port_get_link_speed(struct tb_port *port)
}
}

+/**
+ * tb_port_get_link_generation() - Returns link generation
+ * @port: Lane adapter
+ *
+ * Returns link generation as number or negative errno in case of
+ * failure. Does not distinguish between Thunderbolt 1 and Thunderbolt 2
+ * links so for those always returns 2.
+ */
+int tb_port_get_link_generation(struct tb_port *port)
+{
+ int ret;
+
+ ret = tb_port_get_link_speed(port);
+ if (ret < 0)
+ return ret;
+
+ switch (ret) {
+ case 40:
+ return 4;
+ case 20:
+ return 3;
+ default:
+ return 2;
+ }
+}
+
/**
* tb_port_get_link_width() - Get current link width
* @port: Port to check (USB4 or CIO)
@@ -966,11 +992,6 @@ static bool tb_port_is_width_supported(struct tb_port *port,
return widths & width_mask;
}

-static bool is_gen4_link(struct tb_port *port)
-{
- return tb_port_get_link_speed(port) > 20;
-}
-
/**
* tb_port_set_link_width() - Set target link width of the lane adapter
* @port: Lane adapter
@@ -998,7 +1019,7 @@ int tb_port_set_link_width(struct tb_port *port, enum tb_link_width width)
switch (width) {
case TB_LINK_WIDTH_SINGLE:
/* Gen 4 link cannot be single */
- if (is_gen4_link(port))
+ if (tb_port_get_link_generation(port) >= 4)
return -EOPNOTSUPP;
val |= LANE_ADP_CS_1_TARGET_WIDTH_SINGLE <<
LANE_ADP_CS_1_TARGET_WIDTH_SHIFT;
@@ -1147,7 +1168,8 @@ int tb_port_wait_for_link_width(struct tb_port *port, unsigned int width_mask,
int ret;

/* Gen 4 link does not support single lane */
- if ((width_mask & TB_LINK_WIDTH_SINGLE) && is_gen4_link(port))
+ if ((width_mask & TB_LINK_WIDTH_SINGLE) &&
+ tb_port_get_link_generation(port) >= 4)
return -EOPNOTSUPP;

do {
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 8a75aabb9ce8..2f5f85666302 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -1062,6 +1062,7 @@ static inline bool tb_port_use_credit_allocation(const struct tb_port *port)
(p) = tb_next_port_on_path((src), (dst), (p)))

int tb_port_get_link_speed(struct tb_port *port);
+int tb_port_get_link_generation(struct tb_port *port);
int tb_port_get_link_width(struct tb_port *port);
int tb_port_set_link_width(struct tb_port *port, enum tb_link_width width);
int tb_port_lane_bonding_enable(struct tb_port *port);
--
2.45.1