// SPDX-License-Identifier: GPL-2.0
/*
* Thunderbolt/USB4 retimer support.
*
* Copyright (C) 2020, Intel Corporation
* Authors: Kranthi Kuntala <[email protected]>
* Mika Westerberg <[email protected]>
*/
#include <linux/delay.h>
#include <linux/pm_runtime.h>
#include <linux/sched/signal.h>
#include "sb_regs.h"
#include "tb.h"
#if IS_ENABLED(CONFIG_USB4_DEBUGFS_MARGINING)
#define TB_MAX_RETIMER_INDEX 6
#else
#define TB_MAX_RETIMER_INDEX 2
#endif
/**
* tb_retimer_nvm_read() - Read contents of retimer NVM
* @rt: Retimer device
* @address: NVM address (in bytes) to start reading
* @buf: Data read from NVM is stored here
* @size: Number of bytes to read
*
* Reads retimer NVM and copies the contents to @buf. Returns %0 if the
* read was successful and negative errno in case of failure.
*/
int tb_retimer_nvm_read(struct tb_retimer *rt, unsigned int address, void *buf,
size_t size)
{
return usb4_port_retimer_nvm_read(rt->port, rt->index, address, buf, size);
}
static int nvm_read(void *priv, unsigned int offset, void *val, size_t bytes)
{
struct tb_nvm *nvm = priv;
struct tb_retimer *rt = tb_to_retimer(nvm->dev);
int ret;
pm_runtime_get_sync(&rt->dev);
if (!mutex_trylock(&rt->tb->lock)) {
ret = restart_syscall();
goto out;
}
ret = tb_retimer_nvm_read(rt, offset, val, bytes);
mutex_unlock(&rt->tb->lock);
out:
pm_runtime_mark_last_busy(&rt->dev);
pm_runtime_put_autosuspend(&rt->dev);
return ret;
}
static int nvm_write(void *priv, unsigned int offset, void *val, size_t bytes)
{
struct tb_nvm *nvm = priv;
struct tb_retimer *rt = tb_to_retimer(nvm->dev);
int ret = 0;
if (!mutex_trylock(&rt->tb->lock))
return restart_syscall();
ret = tb_nvm_write_buf(nvm, offset, val, bytes);
mutex_unlock(&rt->tb->lock);
return ret;
}
static int tb_retimer_nvm_add(struct tb_retimer *rt)
{
struct tb_nvm *nvm;
int ret;
nvm = tb_nvm_alloc(&rt->dev);
if (IS_ERR(nvm)) {
ret = PTR_ERR(nvm) == -EOPNOTSUPP ? 0 : PTR_ERR(nvm);
goto err_nvm;
}
ret = tb_nvm_read_version(nvm);
if (ret)
goto err_nvm;
ret = tb_nvm_add_active(nvm, nvm_read);
if (ret)
goto err_nvm;
ret = tb_nvm_add_non_active(nvm, nvm_write);
if (ret)
goto err_nvm;
rt->nvm = nvm;
dev_dbg(&rt->dev, "NVM version %x.%x\n", nvm->major, nvm->minor);
return 0;
err_nvm:
dev_dbg(&rt->dev, "NVM upgrade disabled\n");
if (!IS_ERR(nvm))
tb_nvm_free(nvm);
return ret;
}
static int tb_retimer_nvm_validate_and_write(struct tb_retimer *rt)
{
unsigned int image_size;
const u8 *buf;
int ret;
ret = tb_nvm_validate(rt->nvm);
if (ret)
return ret;
buf = rt->nvm->buf_data_start;
image_size = rt->nvm->buf_data_size;
ret = usb4_port_retimer_nvm_write(rt->port, rt->index, 0, buf,
image_size);
if (ret)
return ret;
rt->nvm->flushed = true;
return 0;
}
static int tb_retimer_nvm_authenticate(struct tb_retimer *rt, bool auth_only)
{
u32 status;
int ret;
if (auth_only) {
ret = usb4_port_retimer_nvm_set_offset(rt->port, rt->index, 0);
if (ret)
return ret;
}
ret = usb4_port_retimer_nvm_authenticate(rt->port, rt->index);
if (ret)
return ret;
usleep_range(100, 150);
/*
* Check the status now if we still can access the retimer. It
* is expected that the below fails.
*/
ret = usb4_port_retimer_nvm_authenticate_status(rt->port, rt->index,
&status);
if (!ret) {
rt->auth_status = status;
return status ? -EINVAL : 0;
}
return 0;
}
static ssize_t device_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct tb_retimer *rt = tb_to_retimer(dev);
return sysfs_emit(buf, "%#x\n", rt->device);
}
static DEVICE_ATTR_RO(device);
static ssize_t nvm_authenticate_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct tb_retimer *rt = tb_to_retimer(dev);
int ret;
if (!mutex_trylock(&rt->tb->lock))
return restart_syscall();
if (!rt->nvm)
ret = -EAGAIN;
else if (rt->no_nvm_upgrade)
ret = -EOPNOTSUPP;
else
ret = sysfs_emit(buf, "%#x\n", rt->auth_status);
mutex_unlock(&rt->tb->lock);
return ret;
}
static void tb_retimer_nvm_authenticate_status(struct tb_port *port, u32 *status)
{
int i;
tb_port_dbg(port, "reading NVM authentication status of retimers\n");
/*
* Before doing anything else, read the authentication status.
* If the retimer has it set, store it for the new retimer
* device instance.
*/
for (i = 1; i <= TB_MAX_RETIMER_INDEX; i++) {
if (usb4_port_retimer_nvm_authenticate_status(port, i, &status[i]))
break;
}
}
static void tb_retimer_set_inbound_sbtx(struct tb_port *port)
{
int i;
/*
* When USB4 port is online sideband communications are
* already up.
*/
if (!usb4_port_device_is_offline(port->usb4))
return;
tb_port_dbg(port, "enabling sideband transactions\n");
for (i = 1; i <= TB_MAX_RETIMER_INDEX; i++)
usb4_port_retimer_set_inbound_sbtx(port, i);
}
static void tb_retimer_unset_inbound_sbtx(struct tb_port *port)
{
int i;
/*
* When USB4 port is offline we need to keep the sideband
* communications up to make it possible to communicate with
* the connected retimers.
*/
if (usb4_port_device_is_offline(port->usb4))
return;
tb_port_dbg(port, "disabling sideband transactions\n");
for (i = TB_MAX_RETIMER_INDEX; i >= 1; i--) {
if (usb4_port_retimer_unset_inbound_sbtx(port, i))
break;
}
}
static ssize_t nvm_authenticate_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct tb_retimer *rt = tb_to_retimer(dev);
int val, ret;
pm_runtime_get_sync(&rt->dev);
if (!mutex_trylock(&rt->tb->lock)) {
ret = restart_syscall();
goto exit_rpm;
}
if (!rt->nvm) {
ret = -EAGAIN;
goto exit_unlock;
}
ret = kstrtoint(buf, 10, &val);
if (ret)
goto exit_unlock;
/* Always clear status */
rt->auth_status = 0;
if (val) {
/*
* When NVM authentication starts the retimer is not
* accessible so calling tb_retimer_unset_inbound_sbtx()
* will fail and therefore we do not call it. Exception
* is when the validation fails or we only write the new
* NVM image without authentication.
*/
tb_retimer_set_inbound_sbtx(rt->port);
if (val == AUTHENTICATE_ONLY) {
ret = tb_retimer_nvm_authenticate(rt, true);
} else {
if (!rt->nvm->flushed) {
if (!rt->nvm->buf) {
ret = -EINVAL;
goto exit_unlock;
}
ret = tb_retimer_nvm_validate_and_write(rt);
if (ret || val == WRITE_ONLY)
goto exit_unlock;
}
if (val == WRITE_AND_AUTHENTICATE)
ret = tb_retimer_nvm_authenticate(rt, false);
}
}
exit_unlock:
if (ret || val == WRITE_ONLY)
tb_retimer_unset_inbound_sbtx(rt->port);
mutex_unlock(&rt->tb->lock);
exit_rpm:
pm_runtime_mark_last_busy(&rt->dev);
pm_runtime_put_autosuspend(&rt->dev);
if (ret)
return ret;
return count;
}
static DEVICE_ATTR_RW(nvm_authenticate);
static ssize_t nvm_version_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct tb_retimer *rt = tb_to_retimer(dev);
int ret;
if (!mutex_trylock(&rt->tb->lock))
return restart_syscall();
if (!rt->nvm)
ret = -EAGAIN;
else if (rt->no_nvm_upgrade)
ret = -EOPNOTSUPP;
else
ret = sysfs_emit(buf, "%x.%x\n", rt->nvm->major, rt->nvm->minor);
mutex_unlock(&rt->tb->lock);
return ret;
}
static DEVICE_ATTR_RO(nvm_version);
static ssize_t vendor_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct tb_retimer *rt = tb_to_retimer(dev);
return sysfs_emit(buf, "%#x\n", rt->vendor);
}
static DEVICE_ATTR_RO(vendor);
static struct attribute *retimer_attrs[] = {
&dev_attr_device.attr,
&dev_attr_nvm_authenticate.attr,
&dev_attr_nvm_version.attr,
&dev_attr_vendor.attr,
NULL
};
static const struct attribute_group retimer_group = {
.attrs = retimer_attrs,
};
static const struct attribute_group *retimer_groups[] = {
&retimer_group,
NULL
};
static void tb_retimer_release(struct device *dev)
{
struct tb_retimer *rt = tb_to_retimer(dev);
kfree(rt);
}
const struct device_type tb_retimer_type = {
.name = "thunderbolt_retimer",
.groups = retimer_groups,
.release = tb_retimer_release,
};
static int tb_retimer_add(struct tb_port *port, u8 index, u32 auth_status,
bool on_board)
{
struct tb_retimer *rt;
u32 vendor, device;
int ret;
ret = usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
USB4_SB_VENDOR_ID, &vendor, sizeof(vendor));
if (ret) {
if (ret != -ENODEV)
tb_port_warn(port, "failed read retimer VendorId: %d\n", ret);
return ret;
}
ret = usb4_port_sb_read(port, USB4_SB_TARGET_RETIMER, index,
USB4_SB_PRODUCT_ID, &device, sizeof(device));
if (ret) {
if (ret != -ENODEV)
tb_port_warn(port, "failed read retimer ProductId: %d\n", ret);
return ret;
}
rt = kzalloc(sizeof(*rt), GFP_KERNEL);
if (!rt)
return -ENOMEM;
rt->index = index;
rt->vendor = vendor;
rt->device = device;
rt->auth_status = auth_status;
rt->port = port;
rt->tb = port->sw->tb;
/*
* Only support NVM upgrade for on-board retimers. The retimers
* on the other side of the connection.
*/
if (!on_board || usb4_port_retimer_nvm_sector_size(port, index) <= 0)
rt->no_nvm_upgrade = true;
rt->dev.parent = &port->usb4->dev;
rt->dev.bus = &tb_bus_type;
rt->dev.type = &tb_retimer_type;
dev_set_name(&rt->dev, "%s:%u.%u", dev_name(&port->sw->dev),
port->port, index);
ret = device_register(&rt->dev);
if (ret) {
dev_err(&rt->dev, "failed to register retimer: %d\n", ret);
put_device(&rt->dev);
return ret;
}
ret = tb_retimer_nvm_add(rt);
if (ret) {
dev_err(&rt->dev, "failed to add NVM devices: %d\n", ret);
device_unregister(&rt->dev);
return ret;
}
dev_info(&rt->dev, "new retimer found, vendor=%#x device=%#x\n",
rt->vendor, rt->device);
pm_runtime_no_callbacks(&rt->dev);
pm_runtime_set_active(&rt->dev);
pm_runtime_enable(&rt->dev);
pm_runtime_set_autosuspend_delay(&rt->dev, TB_AUTOSUSPEND_DELAY);
pm_runtime_mark_last_busy(&rt->dev);
pm_runtime_use_autosuspend(&rt->dev);
tb_retimer_debugfs_init(rt);
return 0;
}
static void tb_retimer_remove(struct tb_retimer *rt)
{
dev_info(&rt->dev, "retimer disconnected\n");
tb_retimer_debugfs_remove(rt);
tb_nvm_free(rt->nvm);
device_unregister(&rt->dev);
}
struct tb_retimer_lookup {
const struct tb_port *port;
u8 index;
};
static int retimer_match(struct device *dev, void *data)
{
const struct tb_retimer_lookup *lookup = data;
struct tb_retimer *rt = tb_to_retimer(dev);
return rt && rt->port == lookup->port && rt->index == lookup->index;
}
static struct tb_retimer *tb_port_find_retimer(struct tb_port *port, u8 index)
{
struct tb_retimer_lookup lookup = { .port = port, .index = index };
struct device *dev;
dev = device_find_child(&port->usb4->dev, &lookup, retimer_match);
if (dev)
return tb_to_retimer(dev);
return NULL;
}
/**
* tb_retimer_scan() - Scan for on-board retimers under port
* @port: USB4 port to scan
* @add: If true also registers found retimers
*
* Brings the sideband into a state where retimers can be accessed.
* Then Tries to enumerate on-board retimers connected to @port. Found
* retimers are registered as children of @port if @add is set. Does
* not scan for cable retimers for now.
*/
int tb_retimer_scan(struct tb_port *port, bool add)
{
u32 status[TB_MAX_RETIMER_INDEX + 1] = {};
int ret, i, max, last_idx = 0;
/*
* Send broadcast RT to make sure retimer indices facing this
* port are set.
*/
ret = usb4_port_enumerate_retimers(port);
if (ret)
return ret;
/*
* Immediately after sending enumerate retimers read the
* authentication status of each retimer.
*/
tb_retimer_nvm_authenticate_status(port, status);
/*
* Enable sideband channel for each retimer. We can do this
* regardless whether there is device connected or not.
*/
tb_retimer_set_inbound_sbtx(port);
for (i = 1; i <= TB_MAX_RETIMER_INDEX; i++) {
/*
* Last retimer is true only for the last on-board
* retimer (the one connected directly to the Type-C
* port).
*/
ret = usb4_port_retimer_is_last(port, i);
if (ret > 0)
last_idx = i;
else if (ret < 0)
break;
}
max = i;
ret = 0;
/* Add retimers if they do not exist already */
for (i = 1; i <= max; i++) {
struct tb_retimer *rt;
/* Skip cable retimers */
if (usb4_port_retimer_is_cable(port, i))
continue;
rt = tb_port_find_retimer(port, i);
if (rt) {
put_device(&rt->dev);
} else if (add) {
ret = tb_retimer_add(port, i, status[i], i <= last_idx);
if (ret && ret != -EOPNOTSUPP)
break;
}
}
tb_retimer_unset_inbound_sbtx(port);
return ret;
}
static int remove_retimer(struct device *dev, void *data)
{
struct tb_retimer *rt = tb_to_retimer(dev);
struct tb_port *port = data;
if (rt && rt->port == port)
tb_retimer_remove(rt);
return 0;
}
/**
* tb_retimer_remove_all() - Remove all retimers under port
* @port: USB4 port whose retimers to remove
*
* This removes all previously added retimers under @port.
*/
void tb_retimer_remove_all(struct tb_port *port)
{
struct usb4_port *usb4;
usb4 = port->usb4;
if (usb4)
device_for_each_child_reverse(&usb4->dev, port,
remove_retimer);
}
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