thunderbolt: Add Display Port CM handshake for Titan Ridge devices (de718ac7) · Commits · 戴 / test

drivers/thunderbolt/tb_regs.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -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

+45 −0

Original line number	Diff line number	Diff line
		@@ -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);