--- /dev/null
+// 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;
+
+ 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;
+
+ return usb4_port_retimer_nvm_write(rt->port, rt->index, 0, buf,
+ image_size);
+}
+
+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);
+ bool val;
+ int 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 = kstrtobool(buf, &val);
+ if (ret)
+ goto exit_unlock;
+
+ /* Always clear status */
+ rt->auth_status = 0;
+
+ if (val) {
+ if (!rt->nvm->buf) {
+ ret = -EINVAL;
+ goto exit_unlock;
+ }
+
+ ret = tb_retimer_nvm_validate_and_write(rt);
+ if (ret)
+ goto exit_unlock;
+
+ ret = usb4_port_retimer_nvm_authenticate(rt->port, rt->index);
+ }
+
+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 tb_retimer *rt;
+ u32 vendor, device;
+ int ret;
+
+ if (!port->cap_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 = &port->sw->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_del(&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->sw->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
+ *
+ * Tries to enumerate on-board retimers connected to @port. Found
+ * retimers are registered as children of @port. Does not scan for cable
+ * retimers for now.
+ */
+int tb_retimer_scan(struct tb_port *port)
+{
+ u32 status[TB_MAX_RETIMER_INDEX] = {};
+ int ret, i, last_idx = 0;
+
+ if (!port->cap_usb4)
+ return 0;
+
+ /*
+ * Send broadcast RT to make sure retimer indices facing this
+ * port are set.
+ */
+ ret = usb4_port_enumerate_retimers(port);
+ if (ret)
+ return ret;
+
+ /*
+ * 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 {
+ ret = tb_retimer_add(port, i, status[i]);
+ if (ret && ret != -EOPNOTSUPP)
+ return ret;
+ }
+ }
+
+ 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)
+{
+ if (port->cap_usb4)
+ device_for_each_child_reverse(&port->sw->dev, port,
+ remove_retimer);
+}
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