Merge tag 'thunderbolt-for-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt into usb-next

Mika writes:

thunderbolt: Changes for v6.9 merge window

This includes following USB4/Thunderbolt changes for the v6.9 merge
window:

  - Reset the topology also for USB4 v1 routers on driver load
  - DisplayPort tunneling and bandwidth allocation mode improvements
  - Tracepoint support for the control channel
  - Couple of minor fixes and cleanups.

All these have been in linux-next with no reported issues.

* tag 'thunderbolt-for-v6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt: (23 commits)
  thunderbolt: Constify the struct device_type usage
  thunderbolt: Add trace events support for the control channel
  thunderbolt: Keep the domain powered when USB4 port is in redrive mode
  thunderbolt: Improve DisplayPort tunnel setup process to be more robust
  thunderbolt: Calculate DisplayPort tunnel bandwidth after DPRX capabilities read
  thunderbolt: Reserve released DisplayPort bandwidth for a group for 10 seconds
  thunderbolt: Introduce tb_tunnel_direction_downstream()
  thunderbolt: Re-order bandwidth group functions
  thunderbolt: Fail the failed bandwidth request properly
  thunderbolt: Log an error if DPTX request is not cleared
  thunderbolt: Handle bandwidth allocation mode disable request
  thunderbolt: Re-calculate estimated bandwidth when allocation mode is enabled
  thunderbolt: Use DP_LOCAL_CAP for maximum bandwidth calculation
  thunderbolt: Correct typo in host_reset parameter
  thunderbolt: Skip discovery also in USB4 v2 host
  thunderbolt: Reset only non-USB4 host routers in resume
  thunderbolt: Remove usage of the deprecated ida_simple_xx() API
  thunderbolt: Fix rollback in tb_port_lane_bonding_enable() for lane 1
  thunderbolt: Fix XDomain rx_lanes_show and tx_lanes_show
  thunderbolt: Reset topology created by the boot firmware
  ...

1 files changed, 45 insertions, 0 deletions

diff --git a/drivers/thunderbolt/lc.c b/drivers/thunderbolt/lc.c
index 633970fbe9b0..63cb4b6afb71 100644
--- a/drivers/thunderbolt/lc.c
+++ b/drivers/thunderbolt/lc.c
@@ -6,6 +6,8 @@
  * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
  */
 
+#include <linux/delay.h>
+
 #include "tb.h"
 
 /**
@@ -45,6 +47,49 @@ static int find_port_lc_cap(struct tb_port *port)
 	return sw->cap_lc + start + phys * size;
 }
 
+/**
+ * tb_lc_reset_port() - Trigger downstream port reset through LC
+ * @port: Port that is reset
+ *
+ * Triggers downstream port reset through link controller registers.
+ * Returns %0 in case of success negative errno otherwise. Only supports
+ * non-USB4 routers with link controller (that's Thunderbolt 2 and
+ * Thunderbolt 3).
+ */
+int tb_lc_reset_port(struct tb_port *port)
+{
+	struct tb_switch *sw = port->sw;
+	int cap, ret;
+	u32 mode;
+
+	if (sw->generation < 2)
+		return -EINVAL;
+
+	cap = find_port_lc_cap(port);
+	if (cap < 0)
+		return cap;
+
+	ret = tb_sw_read(sw, &mode, TB_CFG_SWITCH, cap + TB_LC_PORT_MODE, 1);
+	if (ret)
+		return ret;
+
+	mode |= TB_LC_PORT_MODE_DPR;
+
+	ret = tb_sw_write(sw, &mode, TB_CFG_SWITCH, cap + TB_LC_PORT_MODE, 1);
+	if (ret)
+		return ret;
+
+	fsleep(10000);
+
+	ret = tb_sw_read(sw, &mode, TB_CFG_SWITCH, cap + TB_LC_PORT_MODE, 1);
+	if (ret)
+		return ret;
+
+	mode &= ~TB_LC_PORT_MODE_DPR;
+
+	return tb_sw_write(sw, &mode, TB_CFG_SWITCH, cap + TB_LC_PORT_MODE, 1);
+}
+
 static int tb_lc_set_port_configured(struct tb_port *port, bool configured)
 {
 	bool upstream = tb_is_upstream_port(port);