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-rw-r--r--drivers/thunderbolt/tb.h15
-rw-r--r--drivers/thunderbolt/tb_regs.h32
-rw-r--r--drivers/thunderbolt/usb4.c571
3 files changed, 618 insertions, 0 deletions
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h
index 6c4a26b1c37c..cd6c9eeaf049 100644
--- a/drivers/thunderbolt/tb.h
+++ b/drivers/thunderbolt/tb.h
@@ -1238,6 +1238,21 @@ int usb4_usb3_port_allocate_bandwidth(struct tb_port *port, int *upstream_bw,
int usb4_usb3_port_release_bandwidth(struct tb_port *port, int *upstream_bw,
int *downstream_bw);
+int usb4_dp_port_set_cm_id(struct tb_port *port, int cm_id);
+bool usb4_dp_port_bw_mode_supported(struct tb_port *port);
+bool usb4_dp_port_bw_mode_enabled(struct tb_port *port);
+int usb4_dp_port_set_cm_bw_mode_supported(struct tb_port *port, bool supported);
+int usb4_dp_port_group_id(struct tb_port *port);
+int usb4_dp_port_set_group_id(struct tb_port *port, int group_id);
+int usb4_dp_port_nrd(struct tb_port *port, int *rate, int *lanes);
+int usb4_dp_port_set_nrd(struct tb_port *port, int rate, int lanes);
+int usb4_dp_port_granularity(struct tb_port *port);
+int usb4_dp_port_set_granularity(struct tb_port *port, int granularity);
+int usb4_dp_port_set_estimated_bw(struct tb_port *port, int bw);
+int usb4_dp_port_allocated_bw(struct tb_port *port);
+int usb4_dp_port_allocate_bw(struct tb_port *port, int bw);
+int usb4_dp_port_requested_bw(struct tb_port *port);
+
static inline bool tb_is_usb4_port_device(const struct device *dev)
{
return dev->type == &usb4_port_device_type;
diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h
index f4a194cc0d63..2636423748cd 100644
--- a/drivers/thunderbolt/tb_regs.h
+++ b/drivers/thunderbolt/tb_regs.h
@@ -385,15 +385,42 @@ struct tb_regs_port_header {
#define ADP_DP_CS_1_AUX_RX_HOPID_MASK GENMASK(21, 11)
#define ADP_DP_CS_1_AUX_RX_HOPID_SHIFT 11
#define ADP_DP_CS_2 0x02
+#define ADP_DP_CS_2_NRD_MLC_MASK GENMASK(2, 0)
#define ADP_DP_CS_2_HDP BIT(6)
+#define ADP_DP_CS_2_NRD_MLR_MASK GENMASK(9, 7)
+#define ADP_DP_CS_2_NRD_MLR_SHIFT 7
+#define ADP_DP_CS_2_CA BIT(10)
+#define ADP_DP_CS_2_GR_MASK GENMASK(12, 11)
+#define ADP_DP_CS_2_GR_SHIFT 11
+#define ADP_DP_CS_2_GR_0_25G 0x0
+#define ADP_DP_CS_2_GR_0_5G 0x1
+#define ADP_DP_CS_2_GR_1G 0x2
+#define ADP_DP_CS_2_GROUP_ID_MASK GENMASK(15, 13)
+#define ADP_DP_CS_2_GROUP_ID_SHIFT 13
+#define ADP_DP_CS_2_CM_ID_MASK GENMASK(19, 16)
+#define ADP_DP_CS_2_CM_ID_SHIFT 16
+#define ADP_DP_CS_2_CMMS BIT(20)
+#define ADP_DP_CS_2_ESTIMATED_BW_MASK GENMASK(31, 24)
+#define ADP_DP_CS_2_ESTIMATED_BW_SHIFT 24
#define ADP_DP_CS_3 0x03
#define ADP_DP_CS_3_HDPC BIT(9)
#define DP_LOCAL_CAP 0x04
#define DP_REMOTE_CAP 0x05
+/* For DP IN adapter */
+#define DP_STATUS 0x06
+#define DP_STATUS_ALLOCATED_BW_MASK GENMASK(31, 24)
+#define DP_STATUS_ALLOCATED_BW_SHIFT 24
+/* For DP OUT adapter */
#define DP_STATUS_CTRL 0x06
#define DP_STATUS_CTRL_CMHS BIT(25)
#define DP_STATUS_CTRL_UF BIT(26)
#define DP_COMMON_CAP 0x07
+/* Only if DP IN supports BW allocation mode */
+#define ADP_DP_CS_8 0x08
+#define ADP_DP_CS_8_REQUESTED_BW_MASK GENMASK(7, 0)
+#define ADP_DP_CS_8_DPME BIT(30)
+#define ADP_DP_CS_8_DR BIT(31)
+
/*
* DP_COMMON_CAP offsets work also for DP_LOCAL_CAP and DP_REMOTE_CAP
* with exception of DPRX done.
@@ -410,7 +437,12 @@ struct tb_regs_port_header {
#define DP_COMMON_CAP_2_LANES 0x1
#define DP_COMMON_CAP_4_LANES 0x2
#define DP_COMMON_CAP_LTTPR_NS BIT(27)
+#define DP_COMMON_CAP_BW_MODE BIT(28)
#define DP_COMMON_CAP_DPRX_DONE BIT(31)
+/* Only present if DP IN supports BW allocation mode */
+#define ADP_DP_CS_8 0x08
+#define ADP_DP_CS_8_DPME BIT(30)
+#define ADP_DP_CS_8_DR BIT(31)
/* PCIe adapter registers */
#define ADP_PCIE_CS_0 0x00
diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c
index 2ed50fcbcca7..2a9266fb5c0f 100644
--- a/drivers/thunderbolt/usb4.c
+++ b/drivers/thunderbolt/usb4.c
@@ -2186,3 +2186,574 @@ err_request:
usb4_usb3_port_clear_cm_request(port);
return ret;
}
+
+static bool is_usb4_dpin(const struct tb_port *port)
+{
+ if (!tb_port_is_dpin(port))
+ return false;
+ if (!tb_switch_is_usb4(port->sw))
+ return false;
+ return true;
+}
+
+/**
+ * usb4_dp_port_set_cm_id() - Assign CM ID to the DP IN adapter
+ * @port: DP IN adapter
+ * @cm_id: CM ID to assign
+ *
+ * Sets CM ID for the @port. Returns %0 on success and negative errno
+ * otherwise. Speficially returns %-EOPNOTSUPP if the @port does not
+ * support this.
+ */
+int usb4_dp_port_set_cm_id(struct tb_port *port, int cm_id)
+{
+ u32 val;
+ int ret;
+
+ if (!is_usb4_dpin(port))
+ return -EOPNOTSUPP;
+
+ ret = tb_port_read(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_2, 1);
+ if (ret)
+ return ret;
+
+ val &= ~ADP_DP_CS_2_CM_ID_MASK;
+ val |= cm_id << ADP_DP_CS_2_CM_ID_SHIFT;
+
+ return tb_port_write(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_2, 1);
+}
+
+/**
+ * usb4_dp_port_bw_mode_supported() - Is the bandwidth allocation mode supported
+ * @port: DP IN adapter to check
+ *
+ * Can be called to any DP IN adapter. Returns true if the adapter
+ * supports USB4 bandwidth allocation mode, false otherwise.
+ */
+bool usb4_dp_port_bw_mode_supported(struct tb_port *port)
+{
+ int ret;
+ u32 val;
+
+ if (!is_usb4_dpin(port))
+ return false;
+
+ ret = tb_port_read(port, &val, TB_CFG_PORT,
+ port->cap_adap + DP_LOCAL_CAP, 1);
+ if (ret)
+ return false;
+
+ return !!(val & DP_COMMON_CAP_BW_MODE);
+}
+
+/**
+ * usb4_dp_port_bw_mode_enabled() - Is the bandwidth allocation mode enabled
+ * @port: DP IN adapter to check
+ *
+ * Can be called to any DP IN adapter. Returns true if the bandwidth
+ * allocation mode has been enabled, false otherwise.
+ */
+bool usb4_dp_port_bw_mode_enabled(struct tb_port *port)
+{
+ int ret;
+ u32 val;
+
+ if (!is_usb4_dpin(port))
+ return false;
+
+ ret = tb_port_read(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_8, 1);
+ if (ret)
+ return false;
+
+ return !!(val & ADP_DP_CS_8_DPME);
+}
+
+/**
+ * usb4_dp_port_set_cm_bw_mode_supported() - Set/clear CM support for bandwidth allocation mode
+ * @port: DP IN adapter
+ * @supported: Does the CM support bandwidth allocation mode
+ *
+ * Can be called to any DP IN adapter. Sets or clears the CM support bit
+ * of the DP IN adapter. Returns %0 in success and negative errno
+ * otherwise. Specifically returns %-OPNOTSUPP if the passed in adapter
+ * does not support this.
+ */
+int usb4_dp_port_set_cm_bw_mode_supported(struct tb_port *port, bool supported)
+{
+ u32 val;
+ int ret;
+
+ if (!is_usb4_dpin(port))
+ return -EOPNOTSUPP;
+
+ ret = tb_port_read(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_2, 1);
+ if (ret)
+ return ret;
+
+ if (supported)
+ val |= ADP_DP_CS_2_CMMS;
+ else
+ val &= ~ADP_DP_CS_2_CMMS;
+
+ return tb_port_write(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_2, 1);
+}
+
+/**
+ * usb4_dp_port_group_id() - Return Group ID assigned for the adapter
+ * @port: DP IN adapter
+ *
+ * Reads bandwidth allocation Group ID from the DP IN adapter and
+ * returns it. If the adapter does not support setting Group_ID
+ * %-EOPNOTSUPP is returned.
+ */
+int usb4_dp_port_group_id(struct tb_port *port)
+{
+ u32 val;
+ int ret;
+
+ if (!is_usb4_dpin(port))
+ return -EOPNOTSUPP;
+
+ ret = tb_port_read(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_2, 1);
+ if (ret)
+ return ret;
+
+ return (val & ADP_DP_CS_2_GROUP_ID_MASK) >> ADP_DP_CS_2_GROUP_ID_SHIFT;
+}
+
+/**
+ * usb4_dp_port_set_group_id() - Set adapter Group ID
+ * @port: DP IN adapter
+ * @group_id: Group ID for the adapter
+ *
+ * Sets bandwidth allocation mode Group ID for the DP IN adapter.
+ * Returns %0 in case of success and negative errno otherwise.
+ * Specifically returns %-EOPNOTSUPP if the adapter does not support
+ * this.
+ */
+int usb4_dp_port_set_group_id(struct tb_port *port, int group_id)
+{
+ u32 val;
+ int ret;
+
+ if (!is_usb4_dpin(port))
+ return -EOPNOTSUPP;
+
+ ret = tb_port_read(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_2, 1);
+ if (ret)
+ return ret;
+
+ val &= ~ADP_DP_CS_2_GROUP_ID_MASK;
+ val |= group_id << ADP_DP_CS_2_GROUP_ID_SHIFT;
+
+ return tb_port_write(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_2, 1);
+}
+
+/**
+ * usb4_dp_port_nrd() - Read non-reduced rate and lanes
+ * @port: DP IN adapter
+ * @rate: Non-reduced rate in Mb/s is placed here
+ * @lanes: Non-reduced lanes are placed here
+ *
+ * Reads the non-reduced rate and lanes from the DP IN adapter. Returns
+ * %0 in success and negative errno otherwise. Specifically returns
+ * %-EOPNOTSUPP if the adapter does not support this.
+ */
+int usb4_dp_port_nrd(struct tb_port *port, int *rate, int *lanes)
+{
+ u32 val, tmp;
+ int ret;
+
+ if (!is_usb4_dpin(port))
+ return -EOPNOTSUPP;
+
+ ret = tb_port_read(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_2, 1);
+ if (ret)
+ return ret;
+
+ tmp = (val & ADP_DP_CS_2_NRD_MLR_MASK) >> ADP_DP_CS_2_NRD_MLR_SHIFT;
+ switch (tmp) {
+ case DP_COMMON_CAP_RATE_RBR:
+ *rate = 1620;
+ break;
+ case DP_COMMON_CAP_RATE_HBR:
+ *rate = 2700;
+ break;
+ case DP_COMMON_CAP_RATE_HBR2:
+ *rate = 5400;
+ break;
+ case DP_COMMON_CAP_RATE_HBR3:
+ *rate = 8100;
+ break;
+ }
+
+ tmp = val & ADP_DP_CS_2_NRD_MLC_MASK;
+ switch (tmp) {
+ case DP_COMMON_CAP_1_LANE:
+ *lanes = 1;
+ break;
+ case DP_COMMON_CAP_2_LANES:
+ *lanes = 2;
+ break;
+ case DP_COMMON_CAP_4_LANES:
+ *lanes = 4;
+ break;
+ }
+
+ return 0;
+}
+
+/**
+ * usb4_dp_port_set_nrd() - Set non-reduced rate and lanes
+ * @port: DP IN adapter
+ * @rate: Non-reduced rate in Mb/s
+ * @lanes: Non-reduced lanes
+ *
+ * Before the capabilities reduction this function can be used to set
+ * the non-reduced values for the DP IN adapter. Returns %0 in success
+ * and negative errno otherwise. If the adapter does not support this
+ * %-EOPNOTSUPP is returned.
+ */
+int usb4_dp_port_set_nrd(struct tb_port *port, int rate, int lanes)
+{
+ u32 val;
+ int ret;
+
+ if (!is_usb4_dpin(port))
+ return -EOPNOTSUPP;
+
+ ret = tb_port_read(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_2, 1);
+ if (ret)
+ return ret;
+
+ val &= ~ADP_DP_CS_2_NRD_MLR_MASK;
+
+ switch (rate) {
+ case 1620:
+ break;
+ case 2700:
+ val |= (DP_COMMON_CAP_RATE_HBR << ADP_DP_CS_2_NRD_MLR_SHIFT)
+ & ADP_DP_CS_2_NRD_MLR_MASK;
+ break;
+ case 5400:
+ val |= (DP_COMMON_CAP_RATE_HBR2 << ADP_DP_CS_2_NRD_MLR_SHIFT)
+ & ADP_DP_CS_2_NRD_MLR_MASK;
+ break;
+ case 8100:
+ val |= (DP_COMMON_CAP_RATE_HBR3 << ADP_DP_CS_2_NRD_MLR_SHIFT)
+ & ADP_DP_CS_2_NRD_MLR_MASK;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ val &= ~ADP_DP_CS_2_NRD_MLC_MASK;
+
+ switch (lanes) {
+ case 1:
+ break;
+ case 2:
+ val |= DP_COMMON_CAP_2_LANES;
+ break;
+ case 4:
+ val |= DP_COMMON_CAP_4_LANES;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return tb_port_write(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_2, 1);
+}
+
+/**
+ * usb4_dp_port_granularity() - Return granularity for the bandwidth values
+ * @port: DP IN adapter
+ *
+ * Reads the programmed granularity from @port. If the DP IN adapter does
+ * not support bandwidth allocation mode returns %-EOPNOTSUPP and negative
+ * errno in other error cases.
+ */
+int usb4_dp_port_granularity(struct tb_port *port)
+{
+ u32 val;
+ int ret;
+
+ if (!is_usb4_dpin(port))
+ return -EOPNOTSUPP;
+
+ ret = tb_port_read(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_2, 1);
+ if (ret)
+ return ret;
+
+ val &= ADP_DP_CS_2_GR_MASK;
+ val >>= ADP_DP_CS_2_GR_SHIFT;
+
+ switch (val) {
+ case ADP_DP_CS_2_GR_0_25G:
+ return 250;
+ case ADP_DP_CS_2_GR_0_5G:
+ return 500;
+ case ADP_DP_CS_2_GR_1G:
+ return 1000;
+ }
+
+ return -EINVAL;
+}
+
+/**
+ * usb4_dp_port_set_granularity() - Set granularity for the bandwidth values
+ * @port: DP IN adapter
+ * @granularity: Granularity in Mb/s. Supported values: 1000, 500 and 250.
+ *
+ * Sets the granularity used with the estimated, allocated and requested
+ * bandwidth. Returns %0 in success and negative errno otherwise. If the
+ * adapter does not support this %-EOPNOTSUPP is returned.
+ */
+int usb4_dp_port_set_granularity(struct tb_port *port, int granularity)
+{
+ u32 val;
+ int ret;
+
+ if (!is_usb4_dpin(port))
+ return -EOPNOTSUPP;
+
+ ret = tb_port_read(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_2, 1);
+ if (ret)
+ return ret;
+
+ val &= ~ADP_DP_CS_2_GR_MASK;
+
+ switch (granularity) {
+ case 250:
+ val |= ADP_DP_CS_2_GR_0_25G << ADP_DP_CS_2_GR_SHIFT;
+ break;
+ case 500:
+ val |= ADP_DP_CS_2_GR_0_5G << ADP_DP_CS_2_GR_SHIFT;
+ break;
+ case 1000:
+ val |= ADP_DP_CS_2_GR_1G << ADP_DP_CS_2_GR_SHIFT;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return tb_port_write(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_2, 1);
+}
+
+/**
+ * usb4_dp_port_set_estimated_bw() - Set estimated bandwidth
+ * @port: DP IN adapter
+ * @bw: Estimated bandwidth in Mb/s.
+ *
+ * Sets the estimated bandwidth to @bw. Set the granularity by calling
+ * usb4_dp_port_set_granularity() before calling this. The @bw is round
+ * down to the closest granularity multiplier. Returns %0 in success
+ * and negative errno otherwise. Specifically returns %-EOPNOTSUPP if
+ * the adapter does not support this.
+ */
+int usb4_dp_port_set_estimated_bw(struct tb_port *port, int bw)
+{
+ u32 val, granularity;
+ int ret;
+
+ if (!is_usb4_dpin(port))
+ return -EOPNOTSUPP;
+
+ ret = usb4_dp_port_granularity(port);
+ if (ret < 0)
+ return ret;
+ granularity = ret;
+
+ ret = tb_port_read(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_2, 1);
+ if (ret)
+ return ret;
+
+ val &= ~ADP_DP_CS_2_ESTIMATED_BW_MASK;
+ val |= (bw / granularity) << ADP_DP_CS_2_ESTIMATED_BW_SHIFT;
+
+ return tb_port_write(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_2, 1);
+}
+
+/**
+ * usb4_dp_port_allocated_bw() - Return allocated bandwidth
+ * @port: DP IN adapter
+ *
+ * Reads and returns allocated bandwidth for @port in Mb/s (taking into
+ * account the programmed granularity). Returns negative errno in case
+ * of error.
+ */
+int usb4_dp_port_allocated_bw(struct tb_port *port)
+{
+ u32 val, granularity;
+ int ret;
+
+ if (!is_usb4_dpin(port))
+ return -EOPNOTSUPP;
+
+ ret = usb4_dp_port_granularity(port);
+ if (ret < 0)
+ return ret;
+ granularity = ret;
+
+ ret = tb_port_read(port, &val, TB_CFG_PORT,
+ port->cap_adap + DP_STATUS, 1);
+ if (ret)
+ return ret;
+
+ val &= DP_STATUS_ALLOCATED_BW_MASK;
+ val >>= DP_STATUS_ALLOCATED_BW_SHIFT;
+
+ return val * granularity;
+}
+
+static int __usb4_dp_port_set_cm_ack(struct tb_port *port, bool ack)
+{
+ u32 val;
+ int ret;
+
+ ret = tb_port_read(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_2, 1);
+ if (ret)
+ return ret;
+
+ if (ack)
+ val |= ADP_DP_CS_2_CA;
+ else
+ val &= ~ADP_DP_CS_2_CA;
+
+ return tb_port_write(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_2, 1);
+}
+
+static inline int usb4_dp_port_set_cm_ack(struct tb_port *port)
+{
+ return __usb4_dp_port_set_cm_ack(port, true);
+}
+
+static int usb4_dp_port_wait_and_clear_cm_ack(struct tb_port *port,
+ int timeout_msec)
+{
+ ktime_t end;
+ u32 val;
+ int ret;
+
+ ret = __usb4_dp_port_set_cm_ack(port, false);
+ if (ret)
+ return ret;
+
+ end = ktime_add_ms(ktime_get(), timeout_msec);
+ do {
+ ret = tb_port_read(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_8, 1);
+ if (ret)
+ return ret;
+
+ if (!(val & ADP_DP_CS_8_DR))
+ break;
+
+ usleep_range(50, 100);
+ } while (ktime_before(ktime_get(), end));
+
+ if (val & ADP_DP_CS_8_DR)
+ return -ETIMEDOUT;
+
+ ret = tb_port_read(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_2, 1);
+ if (ret)
+ return ret;
+
+ val &= ~ADP_DP_CS_2_CA;
+ return tb_port_write(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_2, 1);
+}
+
+/**
+ * usb4_dp_port_allocate_bw() - Set allocated bandwidth
+ * @port: DP IN adapter
+ * @bw: New allocated bandwidth in Mb/s
+ *
+ * Communicates the new allocated bandwidth with the DPCD (graphics
+ * driver). Takes into account the programmed granularity. Returns %0 in
+ * success and negative errno in case of error.
+ */
+int usb4_dp_port_allocate_bw(struct tb_port *port, int bw)
+{
+ u32 val, granularity;
+ int ret;
+
+ if (!is_usb4_dpin(port))
+ return -EOPNOTSUPP;
+
+ ret = usb4_dp_port_granularity(port);
+ if (ret < 0)
+ return ret;
+ granularity = ret;
+
+ ret = tb_port_read(port, &val, TB_CFG_PORT,
+ port->cap_adap + DP_STATUS, 1);
+ if (ret)
+ return ret;
+
+ val &= ~DP_STATUS_ALLOCATED_BW_MASK;
+ val |= (bw / granularity) << DP_STATUS_ALLOCATED_BW_SHIFT;
+
+ ret = tb_port_write(port, &val, TB_CFG_PORT,
+ port->cap_adap + DP_STATUS, 1);
+ if (ret)
+ return ret;
+
+ ret = usb4_dp_port_set_cm_ack(port);
+ if (ret)
+ return ret;
+
+ return usb4_dp_port_wait_and_clear_cm_ack(port, 500);
+}
+
+/**
+ * usb4_dp_port_requested_bw() - Read requested bandwidth
+ * @port: DP IN adapter
+ *
+ * Reads the DPCD (graphics driver) requested bandwidth and returns it
+ * in Mb/s. Takes the programmed granularity into account. In case of
+ * error returns negative errno. Specifically returns %-EOPNOTSUPP if
+ * the adapter does not support bandwidth allocation mode.
+ */
+int usb4_dp_port_requested_bw(struct tb_port *port)
+{
+ u32 val, granularity;
+ int ret;
+
+ if (!is_usb4_dpin(port))
+ return -EOPNOTSUPP;
+
+ ret = usb4_dp_port_granularity(port);
+ if (ret < 0)
+ return ret;
+ granularity = ret;
+
+ ret = tb_port_read(port, &val, TB_CFG_PORT,
+ port->cap_adap + ADP_DP_CS_8, 1);
+ if (ret)
+ return 0;
+
+ if (!(val & ADP_DP_CS_8_DR))
+ return 0;
+
+ return (val & ADP_DP_CS_8_REQUESTED_BW_MASK) * granularity;
+}