--- /dev/null
+/*
+ * Thunderbolt Cactus Ridge driver - control channel and configuration commands
+ *
+ * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
+ */
+
+#include <linux/crc32.h>
+#include <linux/slab.h>
+#include <linux/pci.h>
+#include <linux/dmapool.h>
+#include <linux/workqueue.h>
+#include <linux/kfifo.h>
+
+#include "ctl.h"
+
+
+struct ctl_pkg {
+ struct tb_ctl *ctl;
+ void *buffer;
+ struct ring_frame frame;
+};
+
+#define TB_CTL_RX_PKG_COUNT 10
+
+/**
+ * struct tb_cfg - thunderbolt control channel
+ */
+struct tb_ctl {
+ struct tb_nhi *nhi;
+ struct tb_ring *tx;
+ struct tb_ring *rx;
+
+ struct dma_pool *frame_pool;
+ struct ctl_pkg *rx_packets[TB_CTL_RX_PKG_COUNT];
+ DECLARE_KFIFO(response_fifo, struct ctl_pkg*, 16);
+ struct completion response_ready;
+
+ hotplug_cb callback;
+ void *callback_data;
+};
+
+
+#define tb_ctl_WARN(ctl, format, arg...) \
+ dev_WARN(&(ctl)->nhi->pdev->dev, format, ## arg)
+
+#define tb_ctl_err(ctl, format, arg...) \
+ dev_err(&(ctl)->nhi->pdev->dev, format, ## arg)
+
+#define tb_ctl_warn(ctl, format, arg...) \
+ dev_warn(&(ctl)->nhi->pdev->dev, format, ## arg)
+
+#define tb_ctl_info(ctl, format, arg...) \
+ dev_info(&(ctl)->nhi->pdev->dev, format, ## arg)
+
+
+/* configuration packets definitions */
+
+enum tb_cfg_pkg_type {
+ TB_CFG_PKG_READ = 1,
+ TB_CFG_PKG_WRITE = 2,
+ TB_CFG_PKG_ERROR = 3,
+ TB_CFG_PKG_NOTIFY_ACK = 4,
+ TB_CFG_PKG_EVENT = 5,
+ TB_CFG_PKG_XDOMAIN_REQ = 6,
+ TB_CFG_PKG_XDOMAIN_RESP = 7,
+ TB_CFG_PKG_OVERRIDE = 8,
+ TB_CFG_PKG_RESET = 9,
+ TB_CFG_PKG_PREPARE_TO_SLEEP = 0xd,
+};
+
+/* common header */
+struct tb_cfg_header {
+ u32 route_hi:22;
+ u32 unknown:10; /* highest order bit is set on replies */
+ u32 route_lo;
+} __packed;
+
+/* additional header for read/write packets */
+struct tb_cfg_address {
+ u32 offset:13; /* in dwords */
+ u32 length:6; /* in dwords */
+ u32 port:6;
+ enum tb_cfg_space space:2;
+ u32 seq:2; /* sequence number */
+ u32 zero:3;
+} __packed;
+
+/* TB_CFG_PKG_READ, response for TB_CFG_PKG_WRITE */
+struct cfg_read_pkg {
+ struct tb_cfg_header header;
+ struct tb_cfg_address addr;
+} __packed;
+
+/* TB_CFG_PKG_WRITE, response for TB_CFG_PKG_READ */
+struct cfg_write_pkg {
+ struct tb_cfg_header header;
+ struct tb_cfg_address addr;
+ u32 data[64]; /* maximum size, tb_cfg_address.length has 6 bits */
+} __packed;
+
+/* TB_CFG_PKG_ERROR */
+struct cfg_error_pkg {
+ struct tb_cfg_header header;
+ enum tb_cfg_error error:4;
+ u32 zero1:4;
+ u32 port:6;
+ u32 zero2:2; /* Both should be zero, still they are different fields. */
+ u32 zero3:16;
+} __packed;
+
+/* TB_CFG_PKG_EVENT */
+struct cfg_event_pkg {
+ struct tb_cfg_header header;
+ u32 port:6;
+ u32 zero:25;
+ bool unplug:1;
+} __packed;
+
+/* TB_CFG_PKG_RESET */
+struct cfg_reset_pkg {
+ struct tb_cfg_header header;
+} __packed;
+
+/* TB_CFG_PKG_PREPARE_TO_SLEEP */
+struct cfg_pts_pkg {
+ struct tb_cfg_header header;
+ u32 data;
+} __packed;
+
+
+/* utility functions */
+
+static u64 get_route(struct tb_cfg_header header)
+{
+ return (u64) header.route_hi << 32 | header.route_lo;
+}
+
+static struct tb_cfg_header make_header(u64 route)
+{
+ struct tb_cfg_header header = {
+ .route_hi = route >> 32,
+ .route_lo = route,
+ };
+ /* check for overflow, route_hi is not 32 bits! */
+ WARN_ON(get_route(header) != route);
+ return header;
+}
+
+static int check_header(struct ctl_pkg *pkg, u32 len, enum tb_cfg_pkg_type type,
+ u64 route)
+{
+ struct tb_cfg_header *header = pkg->buffer;
+
+ /* check frame, TODO: frame flags */
+ if (WARN(len != pkg->frame.size,
+ "wrong framesize (expected %#x, got %#x)\n",
+ len, pkg->frame.size))
+ return -EIO;
+ if (WARN(type != pkg->frame.eof, "wrong eof (expected %#x, got %#x)\n",
+ type, pkg->frame.eof))
+ return -EIO;
+ if (WARN(pkg->frame.sof, "wrong sof (expected 0x0, got %#x)\n",
+ pkg->frame.sof))
+ return -EIO;
+
+ /* check header */
+ if (WARN(header->unknown != 1 << 9,
+ "header->unknown is %#x\n", header->unknown))
+ return -EIO;
+ if (WARN(route != get_route(*header),
+ "wrong route (expected %llx, got %llx)",
+ route, get_route(*header)))
+ return -EIO;
+ return 0;
+}
+
+static int check_config_address(struct tb_cfg_address addr,
+ enum tb_cfg_space space, u32 offset,
+ u32 length)
+{
+ if (WARN(addr.zero, "addr.zero is %#x\n", addr.zero))
+ return -EIO;
+ if (WARN(space != addr.space, "wrong space (expected %x, got %x\n)",
+ space, addr.space))
+ return -EIO;
+ if (WARN(offset != addr.offset, "wrong offset (expected %x, got %x\n)",
+ offset, addr.offset))
+ return -EIO;
+ if (WARN(length != addr.length, "wrong space (expected %x, got %x\n)",
+ length, addr.length))
+ return -EIO;
+ if (WARN(addr.seq, "addr.seq is %#x\n", addr.seq))
+ return -EIO;
+ /*
+ * We cannot check addr->port as it is set to the upstream port of the
+ * sender.
+ */
+ return 0;
+}
+
+static struct tb_cfg_result decode_error(struct ctl_pkg *response)
+{
+ struct cfg_error_pkg *pkg = response->buffer;
+ struct tb_cfg_result res = { 0 };
+ res.response_route = get_route(pkg->header);
+ res.response_port = 0;
+ res.err = check_header(response, sizeof(*pkg), TB_CFG_PKG_ERROR,
+ get_route(pkg->header));
+ if (res.err)
+ return res;
+
+ WARN(pkg->zero1, "pkg->zero1 is %#x\n", pkg->zero1);
+ WARN(pkg->zero2, "pkg->zero1 is %#x\n", pkg->zero1);
+ WARN(pkg->zero3, "pkg->zero1 is %#x\n", pkg->zero1);
+ res.err = 1;
+ res.tb_error = pkg->error;
+ res.response_port = pkg->port;
+ return res;
+
+}
+
+static struct tb_cfg_result parse_header(struct ctl_pkg *pkg, u32 len,
+ enum tb_cfg_pkg_type type, u64 route)
+{
+ struct tb_cfg_header *header = pkg->buffer;
+ struct tb_cfg_result res = { 0 };
+
+ if (pkg->frame.eof == TB_CFG_PKG_ERROR)
+ return decode_error(pkg);
+
+ res.response_port = 0; /* will be updated later for cfg_read/write */
+ res.response_route = get_route(*header);
+ res.err = check_header(pkg, len, type, route);
+ return res;
+}
+
+static void tb_cfg_print_error(struct tb_ctl *ctl,
+ const struct tb_cfg_result *res)
+{
+ WARN_ON(res->err != 1);
+ switch (res->tb_error) {
+ case TB_CFG_ERROR_PORT_NOT_CONNECTED:
+ /* Port is not connected. This can happen during surprise
+ * removal. Do not warn. */
+ return;
+ case TB_CFG_ERROR_INVALID_CONFIG_SPACE:
+ /*
+ * Invalid cfg_space/offset/length combination in
+ * cfg_read/cfg_write.
+ */
+ tb_ctl_WARN(ctl,
+ "CFG_ERROR(%llx:%x): Invalid config space of offset\n",
+ res->response_route, res->response_port);
+ return;
+ case TB_CFG_ERROR_NO_SUCH_PORT:
+ /*
+ * - The route contains a non-existent port.
+ * - The route contains a non-PHY port (e.g. PCIe).
+ * - The port in cfg_read/cfg_write does not exist.
+ */
+ tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Invalid port\n",
+ res->response_route, res->response_port);
+ return;
+ case TB_CFG_ERROR_LOOP:
+ tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Route contains a loop\n",
+ res->response_route, res->response_port);
+ return;
+ default:
+ /* 5,6,7,9 and 11 are also valid error codes */
+ tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Unknown error\n",
+ res->response_route, res->response_port);
+ return;
+ }
+}
+
+static void cpu_to_be32_array(__be32 *dst, u32 *src, size_t len)
+{
+ int i;
+ for (i = 0; i < len; i++)
+ dst[i] = cpu_to_be32(src[i]);
+}
+
+static void be32_to_cpu_array(u32 *dst, __be32 *src, size_t len)
+{
+ int i;
+ for (i = 0; i < len; i++)
+ dst[i] = be32_to_cpu(src[i]);
+}
+
+static __be32 tb_crc(void *data, size_t len)
+{
+ return cpu_to_be32(~__crc32c_le(~0, data, len));
+}
+
+static void tb_ctl_pkg_free(struct ctl_pkg *pkg)
+{
+ if (pkg) {
+ dma_pool_free(pkg->ctl->frame_pool,
+ pkg->buffer, pkg->frame.buffer_phy);
+ kfree(pkg);
+ }
+}
+
+static struct ctl_pkg *tb_ctl_pkg_alloc(struct tb_ctl *ctl)
+{
+ struct ctl_pkg *pkg = kzalloc(sizeof(*pkg), GFP_KERNEL);
+ if (!pkg)
+ return 0;
+ pkg->ctl = ctl;
+ pkg->buffer = dma_pool_alloc(ctl->frame_pool, GFP_KERNEL,
+ &pkg->frame.buffer_phy);
+ if (!pkg->buffer) {
+ kfree(pkg);
+ return 0;
+ }
+ return pkg;
+}
+
+
+/* RX/TX handling */
+
+static void tb_ctl_tx_callback(struct tb_ring *ring, struct ring_frame *frame,
+ bool canceled)
+{
+ struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);
+ tb_ctl_pkg_free(pkg);
+}
+
+/**
+ * tb_cfg_tx() - transmit a packet on the control channel
+ *
+ * len must be a multiple of four.
+ *
+ * Return: Returns 0 on success or an error code on failure.
+ */
+static int tb_ctl_tx(struct tb_ctl *ctl, void *data, size_t len,
+ enum tb_cfg_pkg_type type)
+{
+ int res;
+ struct ctl_pkg *pkg;
+ if (len % 4 != 0) { /* required for le->be conversion */
+ tb_ctl_WARN(ctl, "TX: invalid size: %zu\n", len);
+ return -EINVAL;
+ }
+ if (len > TB_FRAME_SIZE - 4) { /* checksum is 4 bytes */
+ tb_ctl_WARN(ctl, "TX: packet too large: %zu/%d\n",
+ len, TB_FRAME_SIZE - 4);
+ return -EINVAL;
+ }
+ pkg = tb_ctl_pkg_alloc(ctl);
+ if (!pkg)
+ return -ENOMEM;
+ pkg->frame.callback = tb_ctl_tx_callback;
+ pkg->frame.size = len + 4;
+ pkg->frame.sof = type;
+ pkg->frame.eof = type;
+ cpu_to_be32_array(pkg->buffer, data, len / 4);
+ *(u32 *) (pkg->buffer + len) = tb_crc(pkg->buffer, len);
+
+ res = ring_tx(ctl->tx, &pkg->frame);
+ if (res) /* ring is stopped */
+ tb_ctl_pkg_free(pkg);
+ return res;
+}
+
+/**
+ * tb_ctl_handle_plug_event() - acknowledge a plug event, invoke ctl->callback
+ */
+static void tb_ctl_handle_plug_event(struct tb_ctl *ctl,
+ struct ctl_pkg *response)
+{
+ struct cfg_event_pkg *pkg = response->buffer;
+ u64 route = get_route(pkg->header);
+
+ if (check_header(response, sizeof(*pkg), TB_CFG_PKG_EVENT, route)) {
+ tb_ctl_warn(ctl, "malformed TB_CFG_PKG_EVENT\n");
+ return;
+ }
+
+ if (tb_cfg_error(ctl, route, pkg->port, TB_CFG_ERROR_ACK_PLUG_EVENT))
+ tb_ctl_warn(ctl, "could not ack plug event on %llx:%x\n",
+ route, pkg->port);
+ WARN(pkg->zero, "pkg->zero is %#x\n", pkg->zero);
+ ctl->callback(ctl->callback_data, route, pkg->port, pkg->unplug);
+}
+
+static void tb_ctl_rx_submit(struct ctl_pkg *pkg)
+{
+ ring_rx(pkg->ctl->rx, &pkg->frame); /*
+ * We ignore failures during stop.
+ * All rx packets are referenced
+ * from ctl->rx_packets, so we do
+ * not loose them.
+ */
+}
+
+static void tb_ctl_rx_callback(struct tb_ring *ring, struct ring_frame *frame,
+ bool canceled)
+{
+ struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);
+
+ if (canceled)
+ return; /*
+ * ring is stopped, packet is referenced from
+ * ctl->rx_packets.
+ */
+
+ if (frame->size < 4 || frame->size % 4 != 0) {
+ tb_ctl_err(pkg->ctl, "RX: invalid size %#x, dropping packet\n",
+ frame->size);
+ goto rx;
+ }
+
+ frame->size -= 4; /* remove checksum */
+ if (*(u32 *) (pkg->buffer + frame->size)
+ != tb_crc(pkg->buffer, frame->size)) {
+ tb_ctl_err(pkg->ctl,
+ "RX: checksum mismatch, dropping packet\n");
+ goto rx;
+ }
+ be32_to_cpu_array(pkg->buffer, pkg->buffer, frame->size / 4);
+
+ if (frame->eof == TB_CFG_PKG_EVENT) {
+ tb_ctl_handle_plug_event(pkg->ctl, pkg);
+ goto rx;
+ }
+ if (!kfifo_put(&pkg->ctl->response_fifo, pkg)) {
+ tb_ctl_err(pkg->ctl, "RX: fifo is full\n");
+ goto rx;
+ }
+ complete(&pkg->ctl->response_ready);
+ return;
+rx:
+ tb_ctl_rx_submit(pkg);
+}
+
+/**
+ * tb_ctl_rx() - receive a packet from the control channel
+ */
+static struct tb_cfg_result tb_ctl_rx(struct tb_ctl *ctl, void *buffer,
+ size_t length, int timeout_msec,
+ u8 route, enum tb_cfg_pkg_type type)
+{
+ struct tb_cfg_result res;
+ struct ctl_pkg *pkg;
+
+ if (!wait_for_completion_timeout(&ctl->response_ready,
+ msecs_to_jiffies(timeout_msec))) {
+ tb_ctl_WARN(ctl, "RX: timeout\n");
+ return (struct tb_cfg_result) { .err = -ETIMEDOUT };
+ }
+ if (!kfifo_get(&ctl->response_fifo, &pkg)) {
+ tb_ctl_WARN(ctl, "empty kfifo\n");
+ return (struct tb_cfg_result) { .err = -EIO };
+ }
+
+ res = parse_header(pkg, length, type, route);
+ if (!res.err)
+ memcpy(buffer, pkg->buffer, length);
+ tb_ctl_rx_submit(pkg);
+ return res;
+}
+
+
+/* public interface, alloc/start/stop/free */
+
+/**
+ * tb_ctl_alloc() - allocate a control channel
+ *
+ * cb will be invoked once for every hot plug event.
+ *
+ * Return: Returns a pointer on success or NULL on failure.
+ */
+struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, hotplug_cb cb, void *cb_data)
+{
+ int i;
+ struct tb_ctl *ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
+ if (!ctl)
+ return NULL;
+ ctl->nhi = nhi;
+ ctl->callback = cb;
+ ctl->callback_data = cb_data;
+
+ init_completion(&ctl->response_ready);
+ INIT_KFIFO(ctl->response_fifo);
+ ctl->frame_pool = dma_pool_create("thunderbolt_ctl", &nhi->pdev->dev,
+ TB_FRAME_SIZE, 4, 0);
+ if (!ctl->frame_pool)
+ goto err;
+
+ ctl->tx = ring_alloc_tx(nhi, 0, 10);
+ if (!ctl->tx)
+ goto err;
+
+ ctl->rx = ring_alloc_rx(nhi, 0, 10);
+ if (!ctl->rx)
+ goto err;
+
+ for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) {
+ ctl->rx_packets[i] = tb_ctl_pkg_alloc(ctl);
+ if (!ctl->rx_packets[i])
+ goto err;
+ ctl->rx_packets[i]->frame.callback = tb_ctl_rx_callback;
+ }
+
+ tb_ctl_info(ctl, "control channel created\n");
+ return ctl;
+err:
+ tb_ctl_free(ctl);
+ return NULL;
+}
+
+/**
+ * tb_ctl_free() - free a control channel
+ *
+ * Must be called after tb_ctl_stop.
+ *
+ * Must NOT be called from ctl->callback.
+ */
+void tb_ctl_free(struct tb_ctl *ctl)
+{
+ int i;
+ if (ctl->rx)
+ ring_free(ctl->rx);
+ if (ctl->tx)
+ ring_free(ctl->tx);
+
+ /* free RX packets */
+ for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)
+ tb_ctl_pkg_free(ctl->rx_packets[i]);
+
+
+ if (ctl->frame_pool)
+ dma_pool_destroy(ctl->frame_pool);
+ kfree(ctl);
+}
+
+/**
+ * tb_cfg_start() - start/resume the control channel
+ */
+void tb_ctl_start(struct tb_ctl *ctl)
+{
+ int i;
+ tb_ctl_info(ctl, "control channel starting...\n");
+ ring_start(ctl->tx); /* is used to ack hotplug packets, start first */
+ ring_start(ctl->rx);
+ for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)
+ tb_ctl_rx_submit(ctl->rx_packets[i]);
+}
+
+/**
+ * control() - pause the control channel
+ *
+ * All invocations of ctl->callback will have finished after this method
+ * returns.
+ *
+ * Must NOT be called from ctl->callback.
+ */
+void tb_ctl_stop(struct tb_ctl *ctl)
+{
+ ring_stop(ctl->rx);
+ ring_stop(ctl->tx);
+
+ if (!kfifo_is_empty(&ctl->response_fifo))
+ tb_ctl_WARN(ctl, "dangling response in response_fifo\n");
+ kfifo_reset(&ctl->response_fifo);
+ tb_ctl_info(ctl, "control channel stopped\n");
+}
+
+/* public interface, commands */
+
+/**
+ * tb_cfg_error() - send error packet
+ *
+ * Return: Returns 0 on success or an error code on failure.
+ */
+int tb_cfg_error(struct tb_ctl *ctl, u64 route, u32 port,
+ enum tb_cfg_error error)
+{
+ struct cfg_error_pkg pkg = {
+ .header = make_header(route),
+ .port = port,
+ .error = error,
+ };
+ tb_ctl_info(ctl, "resetting error on %llx:%x.\n", route, port);
+ return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_ERROR);
+}
+
+/**
+ * tb_cfg_reset() - send a reset packet and wait for a response
+ *
+ * If the switch at route is incorrectly configured then we will not receive a
+ * reply (even though the switch will reset). The caller should check for
+ * -ETIMEDOUT and attempt to reconfigure the switch.
+ */
+struct tb_cfg_result tb_cfg_reset(struct tb_ctl *ctl, u64 route,
+ int timeout_msec)
+{
+ int err;
+ struct cfg_reset_pkg request = { .header = make_header(route) };
+ struct tb_cfg_header reply;
+
+ err = tb_ctl_tx(ctl, &request, sizeof(request), TB_CFG_PKG_RESET);
+ if (err)
+ return (struct tb_cfg_result) { .err = err };
+
+ return tb_ctl_rx(ctl, &reply, sizeof(reply), timeout_msec, route,
+ TB_CFG_PKG_RESET);
+}
+
+/**
+ * tb_cfg_read() - read from config space into buffer
+ *
+ * Offset and length are in dwords.
+ */
+struct tb_cfg_result tb_cfg_read_raw(struct tb_ctl *ctl, void *buffer,
+ u64 route, u32 port, enum tb_cfg_space space,
+ u32 offset, u32 length, int timeout_msec)
+{
+ struct tb_cfg_result res = { 0 };
+ struct cfg_read_pkg request = {
+ .header = make_header(route),
+ .addr = {
+ .port = port,
+ .space = space,
+ .offset = offset,
+ .length = length,
+ },
+ };
+ struct cfg_write_pkg reply;
+
+ res.err = tb_ctl_tx(ctl, &request, sizeof(request), TB_CFG_PKG_READ);
+ if (res.err)
+ return res;
+
+ res = tb_ctl_rx(ctl, &reply, 12 + 4 * length, timeout_msec, route,
+ TB_CFG_PKG_READ);
+ if (res.err)
+ return res;
+
+ res.response_port = reply.addr.port;
+ res.err = check_config_address(reply.addr, space, offset, length);
+ if (!res.err)
+ memcpy(buffer, &reply.data, 4 * length);
+ return res;
+}
+
+/**
+ * tb_cfg_write() - write from buffer into config space
+ *
+ * Offset and length are in dwords.
+ */
+struct tb_cfg_result tb_cfg_write_raw(struct tb_ctl *ctl, void *buffer,
+ u64 route, u32 port, enum tb_cfg_space space,
+ u32 offset, u32 length, int timeout_msec)
+{
+ struct tb_cfg_result res = { 0 };
+ struct cfg_write_pkg request = {
+ .header = make_header(route),
+ .addr = {
+ .port = port,
+ .space = space,
+ .offset = offset,
+ .length = length,
+ },
+ };
+ struct cfg_read_pkg reply;
+
+ memcpy(&request.data, buffer, length * 4);
+
+ res.err = tb_ctl_tx(ctl, &request, 12 + 4 * length, TB_CFG_PKG_WRITE);
+ if (res.err)
+ return res;
+
+ res = tb_ctl_rx(ctl, &reply, sizeof(reply), timeout_msec, route,
+ TB_CFG_PKG_WRITE);
+ if (res.err)
+ return res;
+
+ res.response_port = reply.addr.port;
+ res.err = check_config_address(reply.addr, space, offset, length);
+ return res;
+}
+
+int tb_cfg_read(struct tb_ctl *ctl, void *buffer, u64 route, u32 port,
+ enum tb_cfg_space space, u32 offset, u32 length)
+{
+ struct tb_cfg_result res = tb_cfg_read_raw(ctl, buffer, route, port,
+ space, offset, length, TB_CFG_DEFAULT_TIMEOUT);
+ if (res.err == 1) {
+ tb_cfg_print_error(ctl, &res);
+ return -EIO;
+ }
+ WARN(res.err, "tb_cfg_read: %d\n", res.err);
+ return res.err;
+}
+
+int tb_cfg_write(struct tb_ctl *ctl, void *buffer, u64 route, u32 port,
+ enum tb_cfg_space space, u32 offset, u32 length)
+{
+ struct tb_cfg_result res = tb_cfg_write_raw(ctl, buffer, route, port,
+ space, offset, length, TB_CFG_DEFAULT_TIMEOUT);
+ if (res.err == 1) {
+ tb_cfg_print_error(ctl, &res);
+ return -EIO;
+ }
+ WARN(res.err, "tb_cfg_write: %d\n", res.err);
+ return res.err;
+}
+
+/**
+ * tb_cfg_get_upstream_port() - get upstream port number of switch at route
+ *
+ * Reads the first dword from the switches TB_CFG_SWITCH config area and
+ * returns the port number from which the reply originated.
+ *
+ * Return: Returns the upstream port number on success or an error code on
+ * failure.
+ */
+int tb_cfg_get_upstream_port(struct tb_ctl *ctl, u64 route)
+{
+ u32 dummy;
+ struct tb_cfg_result res = tb_cfg_read_raw(ctl, &dummy, route, 0,
+ TB_CFG_SWITCH, 0, 1,
+ TB_CFG_DEFAULT_TIMEOUT);
+ if (res.err == 1)
+ return -EIO;
+ if (res.err)
+ return res.err;
+ return res.response_port;
+}
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff