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From: Mika Westerberg <mika.westerberg@linux.intel.com>
To: linux-usb@vger.kernel.org
Cc: Andreas Noever <andreas.noever@gmail.com>,
	Michael Jamet <michael.jamet@intel.com>,
	Mika Westerberg <mika.westerberg@linux.intel.com>,
	Yehezkel Bernat <YehezkelShB@gmail.com>,
	Rajmohan Mani <rajmohan.mani@intel.com>,
	Nicholas Johnson <nicholas.johnson-opensource@outlook.com.au>,
	Lukas Wunner <lukas@wunner.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Alan Stern <stern@rowland.harvard.edu>,
	Mario.Limonciello@dell.com,
	Anthony Wong <anthony.wong@canonical.com>,
	Oliver Neukum <oneukum@suse.com>,
	Christian Kellner <ckellner@redhat.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH 14/25] thunderbolt: Add Display Port CM handshake for Titan Ridge devices
Date: Wed, 23 Oct 2019 14:21:43 +0300	[thread overview]
Message-ID: <20191023112154.64235-15-mika.westerberg@linux.intel.com> (raw)
In-Reply-To: <20191023112154.64235-1-mika.westerberg@linux.intel.com>

Titan Ridge needs an additional connection manager handshake in order to
do proper Display Port tunneling so implement it here.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/thunderbolt/tb_regs.h |  3 +++
 drivers/thunderbolt/tunnel.c  | 45 +++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)

diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h
index 3a39490a954b..8d11b4a2d552 100644
--- a/drivers/thunderbolt/tb_regs.h
+++ b/drivers/thunderbolt/tb_regs.h
@@ -252,6 +252,9 @@ struct tb_regs_port_header {
 #define ADP_DP_CS_3_HDPC			BIT(9)
 #define DP_LOCAL_CAP				0x04
 #define DP_REMOTE_CAP				0x05
+#define DP_STATUS_CTRL				0x06
+#define DP_STATUS_CTRL_CMHS			BIT(25)
+#define DP_STATUS_CTRL_UF			BIT(26)
 
 /* PCIe adapter registers */
 #define ADP_PCIE_CS_0				0x00
diff --git a/drivers/thunderbolt/tunnel.c b/drivers/thunderbolt/tunnel.c
index 3353396e0806..009c2683a386 100644
--- a/drivers/thunderbolt/tunnel.c
+++ b/drivers/thunderbolt/tunnel.c
@@ -6,6 +6,7 @@
  * Copyright (C) 2019, Intel Corporation
  */
 
+#include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/list.h>
 
@@ -242,6 +243,42 @@ struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up,
 	return tunnel;
 }
 
+static int tb_dp_cm_handshake(struct tb_port *in, struct tb_port *out)
+{
+	int timeout = 10;
+	u32 val;
+	int ret;
+
+	/* Both ends need to support this */
+	if (!tb_switch_is_titan_ridge(in->sw) ||
+	    !tb_switch_is_titan_ridge(out->sw))
+		return 0;
+
+	ret = tb_port_read(out, &val, TB_CFG_PORT,
+			   out->cap_adap + DP_STATUS_CTRL, 1);
+	if (ret)
+		return ret;
+
+	val |= DP_STATUS_CTRL_UF | DP_STATUS_CTRL_CMHS;
+
+	ret = tb_port_write(out, &val, TB_CFG_PORT,
+			    out->cap_adap + DP_STATUS_CTRL, 1);
+	if (ret)
+		return ret;
+
+	do {
+		ret = tb_port_read(out, &val, TB_CFG_PORT,
+				   out->cap_adap + DP_STATUS_CTRL, 1);
+		if (ret)
+			return ret;
+		if (!(val & DP_STATUS_CTRL_CMHS))
+			return 0;
+		usleep_range(10, 100);
+	} while (timeout--);
+
+	return -ETIMEDOUT;
+}
+
 static int tb_dp_xchg_caps(struct tb_tunnel *tunnel)
 {
 	struct tb_port *out = tunnel->dst_port;
@@ -256,6 +293,14 @@ static int tb_dp_xchg_caps(struct tb_tunnel *tunnel)
 	if (in->sw->generation < 2 || out->sw->generation < 2)
 		return 0;
 
+	/*
+	 * Perform connection manager handshake between IN and OUT ports
+	 * before capabilities exchange can take place.
+	 */
+	ret = tb_dp_cm_handshake(in, out);
+	if (ret)
+		return ret;
+
 	/* Read both DP_LOCAL_CAP registers */
 	ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,
 			   in->cap_adap + DP_LOCAL_CAP, 1);
-- 
2.23.0


  parent reply	other threads:[~2019-10-23 11:23 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-23 11:21 [PATCH 00/25] thunderbolt: Add support for USB4 Mika Westerberg
2019-10-23 11:21 ` [PATCH 01/25] thunderbolt: Introduce tb_switch_is_icm() Mika Westerberg
2019-10-23 11:21 ` [PATCH 02/25] thunderbolt: Log switch route string on config read/write timeout Mika Westerberg
2019-10-23 11:21 ` [PATCH 03/25] thunderbolt: Log error if adding switch fails Mika Westerberg
2019-10-23 11:21 ` [PATCH 04/25] thunderbolt: Convert basic adapter register names to follow the USB4 spec Mika Westerberg
2019-10-23 11:21 ` [PATCH 05/25] thunderbolt: Convert PCIe " Mika Westerberg
2019-10-23 11:21 ` [PATCH 06/25] thunderbolt: Convert DP " Mika Westerberg
2019-10-23 11:21 ` [PATCH 07/25] thunderbolt: Make tb_sw_write() take const parameter Mika Westerberg
2019-10-23 11:21 ` [PATCH 08/25] thunderbolt: Add helper macro to iterate over switch ports Mika Westerberg
2019-10-23 11:21 ` [PATCH 09/25] thunderbolt: Refactor add_switch() into two functions Mika Westerberg
2019-10-23 11:21 ` [PATCH 10/25] thunderbolt: Add support for lane bonding Mika Westerberg
2019-10-23 11:21 ` [PATCH 11/25] thunderbolt: Add default linking between lane adapters if not provided by DROM Mika Westerberg
2019-10-23 11:21 ` [PATCH 12/25] thunderbolt: Expand controller name in tb_switch_is_xy() Mika Westerberg
2019-10-23 11:21 ` [PATCH 13/25] thunderbolt: Add downstream PCIe port mappings for Alpine and Titan Ridge Mika Westerberg
2019-10-23 11:21 ` Mika Westerberg [this message]
2019-10-23 11:21 ` [PATCH 15/25] thunderbolt: Add Display Port adapter pairing and resource management Mika Westerberg
2019-10-23 11:21 ` [PATCH 16/25] thunderbolt: Add bandwidth management for Display Port tunnels Mika Westerberg
2019-10-23 11:21 ` [PATCH 17/25] thunderbolt: Do not start firmware unless asked by the user Mika Westerberg
2019-10-23 11:21 ` [PATCH 18/25] thunderbolt: Make tb_find_port() available to other files Mika Westerberg
2019-10-23 11:21 ` [PATCH 19/25] thunderbolt: Call tb_eeprom_get_drom_offset() from tb_eeprom_read_n() Mika Westerberg
2019-10-23 11:21 ` [PATCH 20/25] thunderbolt: Add initial support for USB4 Mika Westerberg
2019-10-23 11:21 ` [PATCH 21/25] thunderbolt: Update Kconfig entry to USB4 Mika Westerberg
2019-10-23 11:21 ` [PATCH 22/25] thunderbolt: Make tb_switch_find_cap() available to other files Mika Westerberg
2019-10-23 11:21 ` [PATCH 23/25] thunderbolt: Add support for Time Management Unit Mika Westerberg
2019-10-23 11:21 ` [PATCH 24/25] thunderbolt: Add support for USB 3.x tunnels Mika Westerberg
2019-10-23 11:21 ` [PATCH 25/25] thunderbolt: Update documentation with the USB4 information Mika Westerberg
2019-10-23 15:55 ` [PATCH 00/25] thunderbolt: Add support for USB4 Mario.Limonciello
2019-10-23 16:18   ` Mika Westerberg
2019-11-01 11:43 ` Mika Westerberg
2019-11-04 14:31   ` Greg Kroah-Hartman

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