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linux/drivers/thunderbolt/lc.c
Mika Westerberg fdb0887c5a thunderbolt: Start lane initialization after sleep 
USB4 spec says that for TBT3 compatible device routers the connection
manager needs to set SLI (Start Lane Initialization) to get the lanes
that were not connected back to functional state after sleep. Same needs
to be done if the link was XDomain.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com>
2021-01-11 17:15:42 +03:00

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// SPDX-License-Identifier: GPL-2.0
/*
* Thunderbolt link controller support
*
* Copyright (C) 2019, Intel Corporation
* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
*/
#include "tb.h"
/**
* tb_lc_read_uuid() - Read switch UUID from link controller common register
* @sw: Switch whose UUID is read
* @uuid: UUID is placed here
*/
int tb_lc_read_uuid(struct tb_switch *sw, u32 *uuid)
{
if (!sw->cap_lc)
return -EINVAL;
return tb_sw_read(sw, uuid, TB_CFG_SWITCH, sw->cap_lc + TB_LC_FUSE, 4);
}
static int read_lc_desc(struct tb_switch *sw, u32 *desc)
{
if (!sw->cap_lc)
return -EINVAL;
return tb_sw_read(sw, desc, TB_CFG_SWITCH, sw->cap_lc + TB_LC_DESC, 1);
}
static int find_port_lc_cap(struct tb_port *port)
{
struct tb_switch *sw = port->sw;
int start, phys, ret, size;
u32 desc;
ret = read_lc_desc(sw, &desc);
if (ret)
return ret;
/* Start of port LC registers */
start = (desc & TB_LC_DESC_SIZE_MASK) >> TB_LC_DESC_SIZE_SHIFT;
size = (desc & TB_LC_DESC_PORT_SIZE_MASK) >> TB_LC_DESC_PORT_SIZE_SHIFT;
phys = tb_phy_port_from_link(port->port);
return sw->cap_lc + start + phys * size;
}
static int tb_lc_set_port_configured(struct tb_port *port, bool configured)
{
bool upstream = tb_is_upstream_port(port);
struct tb_switch *sw = port->sw;
u32 ctrl, lane;
int cap, ret;
if (sw->generation < 2)
return 0;
cap = find_port_lc_cap(port);
if (cap < 0)
return cap;
ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1);
if (ret)
return ret;
/* Resolve correct lane */
if (port->port % 2)
lane = TB_LC_SX_CTRL_L1C;
else
lane = TB_LC_SX_CTRL_L2C;
if (configured) {
ctrl |= lane;
if (upstream)
ctrl |= TB_LC_SX_CTRL_UPSTREAM;
} else {
ctrl &= ~lane;
if (upstream)
ctrl &= ~TB_LC_SX_CTRL_UPSTREAM;
}
return tb_sw_write(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1);
}
/**
* tb_lc_configure_port() - Let LC know about configured port
* @port: Port that is set as configured
*
* Sets the port configured for power management purposes.
*/
int tb_lc_configure_port(struct tb_port *port)
{
return tb_lc_set_port_configured(port, true);
}
/**
* tb_lc_unconfigure_port() - Let LC know about unconfigured port
* @port: Port that is set as configured
*
* Sets the port unconfigured for power management purposes.
*/
void tb_lc_unconfigure_port(struct tb_port *port)
{
tb_lc_set_port_configured(port, false);
}
static int tb_lc_set_xdomain_configured(struct tb_port *port, bool configure)
{
struct tb_switch *sw = port->sw;
u32 ctrl, lane;
int cap, ret;
if (sw->generation < 2)
return 0;
cap = find_port_lc_cap(port);
if (cap < 0)
return cap;
ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1);
if (ret)
return ret;
/* Resolve correct lane */
if (port->port % 2)
lane = TB_LC_SX_CTRL_L1D;
else
lane = TB_LC_SX_CTRL_L2D;
if (configure)
ctrl |= lane;
else
ctrl &= ~lane;
return tb_sw_write(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1);
}
/**
* tb_lc_configure_xdomain() - Inform LC that the link is XDomain
* @port: Switch downstream port connected to another host
*
* Sets the lane configured for XDomain accordingly so that the LC knows
* about this. Returns %0 in success and negative errno in failure.
*/
int tb_lc_configure_xdomain(struct tb_port *port)
{
return tb_lc_set_xdomain_configured(port, true);
}
/**
* tb_lc_unconfigure_xdomain() - Unconfigure XDomain from port
* @port: Switch downstream port that was connected to another host
*
* Unsets the lane XDomain configuration.
*/
void tb_lc_unconfigure_xdomain(struct tb_port *port)
{
tb_lc_set_xdomain_configured(port, false);
}
/**
* tb_lc_start_lane_initialization() - Start lane initialization
* @port: Device router lane 0 adapter
*
* Starts lane initialization for @port after the router resumed from
* sleep. Should be called for those downstream lane adapters that were
* not connected (tb_lc_configure_port() was not called) before sleep.
*
* Returns %0 in success and negative errno in case of failure.
*/
int tb_lc_start_lane_initialization(struct tb_port *port)
{
struct tb_switch *sw = port->sw;
int ret, cap;
u32 ctrl;
if (!tb_route(sw))
return 0;
if (sw->generation < 2)
return 0;
cap = find_port_lc_cap(port);
if (cap < 0)
return cap;
ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1);
if (ret)
return ret;
ctrl |= TB_LC_SX_CTRL_SLI;
return tb_sw_write(sw, &ctrl, TB_CFG_SWITCH, cap + TB_LC_SX_CTRL, 1);
}
static int tb_lc_set_wake_one(struct tb_switch *sw, unsigned int offset,
unsigned int flags)
{
u32 ctrl;
int ret;
/*
* Enable wake on PCIe and USB4 (wake coming from another
* router).
*/
ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH,
offset + TB_LC_SX_CTRL, 1);
if (ret)
return ret;
ctrl &= ~(TB_LC_SX_CTRL_WOC | TB_LC_SX_CTRL_WOD | TB_LC_SX_CTRL_WOP |
TB_LC_SX_CTRL_WOU4);
if (flags & TB_WAKE_ON_CONNECT)
ctrl |= TB_LC_SX_CTRL_WOC | TB_LC_SX_CTRL_WOD;
if (flags & TB_WAKE_ON_USB4)
ctrl |= TB_LC_SX_CTRL_WOU4;
if (flags & TB_WAKE_ON_PCIE)
ctrl |= TB_LC_SX_CTRL_WOP;
return tb_sw_write(sw, &ctrl, TB_CFG_SWITCH, offset + TB_LC_SX_CTRL, 1);
}
/**
* tb_lc_set_wake() - Enable/disable wake
* @sw: Switch whose wakes to configure
* @flags: Wakeup flags (%0 to disable)
*
* For each LC sets wake bits accordingly.
*/
int tb_lc_set_wake(struct tb_switch *sw, unsigned int flags)
{
int start, size, nlc, ret, i;
u32 desc;
if (sw->generation < 2)
return 0;
if (!tb_route(sw))
return 0;
ret = read_lc_desc(sw, &desc);
if (ret)
return ret;
/* Figure out number of link controllers */
nlc = desc & TB_LC_DESC_NLC_MASK;
start = (desc & TB_LC_DESC_SIZE_MASK) >> TB_LC_DESC_SIZE_SHIFT;
size = (desc & TB_LC_DESC_PORT_SIZE_MASK) >> TB_LC_DESC_PORT_SIZE_SHIFT;
/* For each link controller set sleep bit */
for (i = 0; i < nlc; i++) {
unsigned int offset = sw->cap_lc + start + i * size;
ret = tb_lc_set_wake_one(sw, offset, flags);
if (ret)
return ret;
}
return 0;
}
/**
* tb_lc_set_sleep() - Inform LC that the switch is going to sleep
* @sw: Switch to set sleep
*
* Let the switch link controllers know that the switch is going to
* sleep.
*/
int tb_lc_set_sleep(struct tb_switch *sw)
{
int start, size, nlc, ret, i;
u32 desc;
if (sw->generation < 2)
return 0;
ret = read_lc_desc(sw, &desc);
if (ret)
return ret;
/* Figure out number of link controllers */
nlc = desc & TB_LC_DESC_NLC_MASK;
start = (desc & TB_LC_DESC_SIZE_MASK) >> TB_LC_DESC_SIZE_SHIFT;
size = (desc & TB_LC_DESC_PORT_SIZE_MASK) >> TB_LC_DESC_PORT_SIZE_SHIFT;
/* For each link controller set sleep bit */
for (i = 0; i < nlc; i++) {
unsigned int offset = sw->cap_lc + start + i * size;
u32 ctrl;
ret = tb_sw_read(sw, &ctrl, TB_CFG_SWITCH,
offset + TB_LC_SX_CTRL, 1);
if (ret)
return ret;
ctrl |= TB_LC_SX_CTRL_SLP;
ret = tb_sw_write(sw, &ctrl, TB_CFG_SWITCH,
offset + TB_LC_SX_CTRL, 1);
if (ret)
return ret;
}
return 0;
}
/**
* tb_lc_lane_bonding_possible() - Is lane bonding possible towards switch
* @sw: Switch to check
*
* Checks whether conditions for lane bonding from parent to @sw are
* possible.
*/
bool tb_lc_lane_bonding_possible(struct tb_switch *sw)
{
struct tb_port *up;
int cap, ret;
u32 val;
if (sw->generation < 2)
return false;
up = tb_upstream_port(sw);
cap = find_port_lc_cap(up);
if (cap < 0)
return false;
ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, cap + TB_LC_PORT_ATTR, 1);
if (ret)
return false;
return !!(val & TB_LC_PORT_ATTR_BE);
}
static int tb_lc_dp_sink_from_port(const struct tb_switch *sw,
struct tb_port *in)
{
struct tb_port *port;
/* The first DP IN port is sink 0 and second is sink 1 */
tb_switch_for_each_port(sw, port) {
if (tb_port_is_dpin(port))
return in != port;
}
return -EINVAL;
}
static int tb_lc_dp_sink_available(struct tb_switch *sw, int sink)
{
u32 val, alloc;
int ret;
ret = tb_sw_read(sw, &val, TB_CFG_SWITCH,
sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
if (ret)
return ret;
/*
* Sink is available for CM/SW to use if the allocation valie is
* either 0 or 1.
*/
if (!sink) {
alloc = val & TB_LC_SNK_ALLOCATION_SNK0_MASK;
if (!alloc || alloc == TB_LC_SNK_ALLOCATION_SNK0_CM)
return 0;
} else {
alloc = (val & TB_LC_SNK_ALLOCATION_SNK1_MASK) >>
TB_LC_SNK_ALLOCATION_SNK1_SHIFT;
if (!alloc || alloc == TB_LC_SNK_ALLOCATION_SNK1_CM)
return 0;
}
return -EBUSY;
}
/**
* tb_lc_dp_sink_query() - Is DP sink available for DP IN port
* @sw: Switch whose DP sink is queried
* @in: DP IN port to check
*
* Queries through LC SNK_ALLOCATION registers whether DP sink is available
* for the given DP IN port or not.
*/
bool tb_lc_dp_sink_query(struct tb_switch *sw, struct tb_port *in)
{
int sink;
/*
* For older generations sink is always available as there is no
* allocation mechanism.
*/
if (sw->generation < 3)
return true;
sink = tb_lc_dp_sink_from_port(sw, in);
if (sink < 0)
return false;
return !tb_lc_dp_sink_available(sw, sink);
}
/**
* tb_lc_dp_sink_alloc() - Allocate DP sink
* @sw: Switch whose DP sink is allocated
* @in: DP IN port the DP sink is allocated for
*
* Allocate DP sink for @in via LC SNK_ALLOCATION registers. If the
* resource is available and allocation is successful returns %0. In all
* other cases returs negative errno. In particular %-EBUSY is returned if
* the resource was not available.
*/
int tb_lc_dp_sink_alloc(struct tb_switch *sw, struct tb_port *in)
{
int ret, sink;
u32 val;
if (sw->generation < 3)
return 0;
sink = tb_lc_dp_sink_from_port(sw, in);
if (sink < 0)
return sink;
ret = tb_lc_dp_sink_available(sw, sink);
if (ret)
return ret;
ret = tb_sw_read(sw, &val, TB_CFG_SWITCH,
sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
if (ret)
return ret;
if (!sink) {
val &= ~TB_LC_SNK_ALLOCATION_SNK0_MASK;
val |= TB_LC_SNK_ALLOCATION_SNK0_CM;
} else {
val &= ~TB_LC_SNK_ALLOCATION_SNK1_MASK;
val |= TB_LC_SNK_ALLOCATION_SNK1_CM <<
TB_LC_SNK_ALLOCATION_SNK1_SHIFT;
}
ret = tb_sw_write(sw, &val, TB_CFG_SWITCH,
sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
if (ret)
return ret;
tb_port_dbg(in, "sink %d allocated\n", sink);
return 0;
}
/**
* tb_lc_dp_sink_dealloc() - De-allocate DP sink
* @sw: Switch whose DP sink is de-allocated
* @in: DP IN port whose DP sink is de-allocated
*
* De-allocate DP sink from @in using LC SNK_ALLOCATION registers.
*/
int tb_lc_dp_sink_dealloc(struct tb_switch *sw, struct tb_port *in)
{
int ret, sink;
u32 val;
if (sw->generation < 3)
return 0;
sink = tb_lc_dp_sink_from_port(sw, in);
if (sink < 0)
return sink;
/* Needs to be owned by CM/SW */
ret = tb_lc_dp_sink_available(sw, sink);
if (ret)
return ret;
ret = tb_sw_read(sw, &val, TB_CFG_SWITCH,
sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
if (ret)
return ret;
if (!sink)
val &= ~TB_LC_SNK_ALLOCATION_SNK0_MASK;
else
val &= ~TB_LC_SNK_ALLOCATION_SNK1_MASK;
ret = tb_sw_write(sw, &val, TB_CFG_SWITCH,
sw->cap_lc + TB_LC_SNK_ALLOCATION, 1);
if (ret)
return ret;
tb_port_dbg(in, "sink %d de-allocated\n", sink);
return 0;
}
/**
* tb_lc_force_power() - Forces LC to be powered on
* @sw: Thunderbolt switch
*
* This is useful to let authentication cycle pass even without
* a Thunderbolt link present.
*/
int tb_lc_force_power(struct tb_switch *sw)
{
u32 in = 0xffff;
return tb_sw_write(sw, &in, TB_CFG_SWITCH, TB_LC_POWER, 1);
}
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