WSL2-Linux-Kernel/drivers/thunderbolt/lc.c

383 строки
8.4 KiB
C

// 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_configure_lane(struct tb_port *port, bool configure)
{
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 (configure) {
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_link() - Let LC know about configured link
* @sw: Switch that is being added
*
* Informs LC of both parent switch and @sw that there is established
* link between the two.
*/
int tb_lc_configure_link(struct tb_switch *sw)
{
struct tb_port *up, *down;
int ret;
if (!tb_route(sw) || tb_switch_is_icm(sw))
return 0;
up = tb_upstream_port(sw);
down = tb_port_at(tb_route(sw), tb_to_switch(sw->dev.parent));
/* Configure parent link toward this switch */
ret = tb_lc_configure_lane(down, true);
if (ret)
return ret;
/* Configure upstream link from this switch to the parent */
ret = tb_lc_configure_lane(up, true);
if (ret)
tb_lc_configure_lane(down, false);
return ret;
}
/**
* tb_lc_unconfigure_link() - Let LC know about unconfigured link
* @sw: Switch to unconfigure
*
* Informs LC of both parent switch and @sw that the link between the
* two does not exist anymore.
*/
void tb_lc_unconfigure_link(struct tb_switch *sw)
{
struct tb_port *up, *down;
if (sw->is_unplugged || !tb_route(sw) || tb_switch_is_icm(sw))
return;
up = tb_upstream_port(sw);
down = tb_port_at(tb_route(sw), tb_to_switch(sw->dev.parent));
tb_lc_configure_lane(up, false);
tb_lc_configure_lane(down, false);
}
/**
* 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);
}