linux/drivers/thunderbolt/retimer.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Thunderbolt/USB4 retimer support.
*
* Copyright (C) 2020, Intel Corporation
* Authors: Kranthi Kuntala <kranthi.kuntala@intel.com>
* Mika Westerberg <mika.westerberg@linux.intel.com>
*/
#include <linux/delay.h>
#include <linux/pm_runtime.h>
#include <linux/sched/signal.h>
#include "sb_regs.h"
#include "tb.h"
#define TB_MAX_RETIMER_INDEX 6
static int tb_retimer_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 = usb4_port_retimer_nvm_read(rt->port, rt->index, 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 tb_retimer_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;
u32 val, nvm_size;
int ret;
nvm = tb_nvm_alloc(&rt->dev);
if (IS_ERR(nvm))
return PTR_ERR(nvm);
ret = usb4_port_retimer_nvm_read(rt->port, rt->index, NVM_VERSION, &val,
sizeof(val));
if (ret)
goto err_nvm;
nvm->major = val >> 16;
nvm->minor = val >> 8;
ret = usb4_port_retimer_nvm_read(rt->port, rt->index, NVM_FLASH_SIZE,
&val, sizeof(val));
if (ret)
goto err_nvm;
nvm_size = (SZ_1M << (val & 7)) / 8;
nvm_size = (nvm_size - SZ_16K) / 2;
ret = tb_nvm_add_active(nvm, nvm_size, tb_retimer_nvm_read);
if (ret)
goto err_nvm;
ret = tb_nvm_add_non_active(nvm, NVM_MAX_SIZE, tb_retimer_nvm_write);
if (ret)
goto err_nvm;
rt->nvm = nvm;
return 0;
err_nvm:
tb_nvm_free(nvm);
return ret;
}
static int tb_retimer_nvm_validate_and_write(struct tb_retimer *rt)
{
unsigned int image_size, hdr_size;
const u8 *buf = rt->nvm->buf;
u16 ds_size, device;
int ret;
image_size = rt->nvm->buf_data_size;
if (image_size < NVM_MIN_SIZE || image_size > NVM_MAX_SIZE)
return -EINVAL;
/*
* FARB pointer must point inside the image and must at least
* contain parts of the digital section we will be reading here.
*/
hdr_size = (*(u32 *)buf) & 0xffffff;
if (hdr_size + NVM_DEVID + 2 >= image_size)
return -EINVAL;
/* Digital section start should be aligned to 4k page */
if (!IS_ALIGNED(hdr_size, SZ_4K))
return -EINVAL;
/*
* Read digital section size and check that it also fits inside
* the image.
*/
ds_size = *(u16 *)(buf + hdr_size);
if (ds_size >= image_size)
return -EINVAL;
/*
* Make sure the device ID in the image matches the retimer
* hardware.
*/
device = *(u16 *)(buf + hdr_size + NVM_DEVID);
if (device != rt->device)
return -EINVAL;
/* Skip headers in the image */
buf += hdr_size;
image_size -= hdr_size;
ret = usb4_port_retimer_nvm_write(rt->port, rt->index, 0, buf,
image_size);
if (!ret)
rt->nvm->flushed = true;
return ret;
}
static int tb_retimer_nvm_authenticate(struct tb_retimer *rt, bool auth_only)
{
int ret;
if (auth_only) {
ret = usb4_port_retimer_nvm_set_offset(rt->port, rt->index, 0);
if (ret)
return ret;
}
return usb4_port_retimer_nvm_authenticate(rt->port, rt->index);
}
static ssize_t device_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct tb_retimer *rt = tb_to_retimer(dev);
return sprintf(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
ret = sprintf(buf, "%#x\n", rt->auth_status);
mutex_unlock(&rt->tb->lock);
return ret;
}
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) {
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:
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
ret = sprintf(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 sprintf(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);
}
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)
{
struct usb4_port *usb4;
struct tb_retimer *rt;
u32 vendor, device;
int ret;
usb4 = port->usb4;
if (!usb4)
return -EINVAL;
ret = usb4_port_retimer_read(port, 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_retimer_read(port, 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;
}
if (vendor != PCI_VENDOR_ID_INTEL && vendor != 0x8087) {
tb_port_info(port, "retimer NVM format of vendor %#x is not supported\n",
vendor);
return -EOPNOTSUPP;
}
/*
* Check that it supports NVM operations. If not then don't add
* the device at all.
*/
ret = usb4_port_retimer_nvm_sector_size(port, index);
if (ret < 0)
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;
rt->dev.parent = &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);
return 0;
}
static void tb_retimer_remove(struct tb_retimer *rt)
{
dev_info(&rt->dev, "retimer disconnected\n");
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, 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;
/*
* Enable sideband channel for each retimer. We can do this
* regardless whether there is device connected or not.
*/
for (i = 1; i <= TB_MAX_RETIMER_INDEX; i++)
usb4_port_retimer_set_inbound_sbtx(port, i);
/*
* 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++)
usb4_port_retimer_nvm_authenticate_status(port, i, &status[i]);
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;
}
if (!last_idx)
return 0;
/* Add on-board retimers if they do not exist already */
for (i = 1; i <= last_idx; i++) {
struct tb_retimer *rt;
rt = tb_port_find_retimer(port, i);
if (rt) {
put_device(&rt->dev);
} else if (add) {
ret = tb_retimer_add(port, i, status[i]);
if (ret && ret != -EOPNOTSUPP)
break;
}
}
return 0;
}
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);
}