Native USB host-side MSC (Mass Storage Class) polled enumeration ladder. More...

#include <stdint.h>
#include "ra8_attributes.h"
#include "ra8_check.h"
#include "ra8_err.h"
#include "ra8_hal_internal.h"
#include "ra8_time.h"
#include "ra8_usb.h"
#include "ra8_usb_hmsc.h"
#include "ra8_usb_hmsc_internal.h"

Include dependency graph for ra8_usb_hmsc_enum.c:

Enumerations
enum	ra8_usb_hmsc_enum_tune_t : uint32_t { k_ra8_hmsc_vbus_settle_ms = 200U , k_ra8_hmsc_attach_to_ms = 2000U , k_ra8_hmsc_debounce_ms = 500U , k_ra8_hmsc_reset_hold_ms = 50U , k_ra8_hmsc_recovery_ms = 20U , k_ra8_hmsc_addr_settle_ms = 5U , k_ra8_hmsc_enum_tries = 8U , k_ra8_hmsc_no_reset_tries = 4U , k_ra8_hmsc_addr_alt_mask = 0x03U , k_ra8_hmsc_cfg_buf_len = 128U , k_ra8_hmsc_attach_spin_limit = 50000000UL }
	Timing / retry tunables for the polled enumeration ladder. More...
enum	ra8_usb_hmsc_walk_off_t : uint8_t { k_ra8_hmsc_off_dlen = 0U , k_ra8_hmsc_off_dtype = 1U , k_ra8_hmsc_off_iface_num = 2U , k_ra8_hmsc_off_iface_class = 5U , k_ra8_hmsc_off_iface_sub = 6U , k_ra8_hmsc_off_iface_proto = 7U , k_ra8_hmsc_off_ep_addr = 2U , k_ra8_hmsc_off_ep_attr = 3U , k_ra8_hmsc_off_ep_mps = 4U , k_ra8_hmsc_off_cfg_total = 2U , k_ra8_hmsc_off_cfg_value = 5U , k_ra8_hmsc_off_dev_vid = 8U , k_ra8_hmsc_off_dev_pid = 10U , k_ra8_hmsc_ep_dir_in_bit = 0x80U , k_ra8_hmsc_ep_num_mask = 0x0FU , k_ra8_hmsc_ep_attr_mask = 0x03U , k_ra8_hmsc_ep_attr_bulk = 0x02U , k_ra8_hmsc_byte_bits = 8U }
	Descriptor-walk byte offsets and identity codes. More...

Functions
static ra8_err_t	internal_enum_read_dev_desc (uint8_t *desc)
	Read the 18-byte device descriptor over the polled control engine.
static ra8_err_t	internal_enum_hunt (uint8_t desc, uint8_t out_addr)
	Wait for a device to attach, then hunt for its address.
static ra8_err_t	internal_enum_assign_addr (uint8_t *dev_addr)
	Move the device to address 1 when it answered at the default.
static void	internal_enum_note_endpoint (const uint8_t *d)
	Record one bulk endpoint descriptor into the device snapshot.
static bool	internal_enum_iface_is_msc (const uint8_t *d)
	Test whether an interface descriptor is MSC SCSI Bulk-Only.
static ra8_err_t	internal_enum_walk_cfg (const uint8_t *cfg, uint16_t len)
	Walk a configuration blob for the MSC interface + bulk endpoints.
static ra8_err_t	internal_enum_read_config (uint8_t *out_cfg_value)
	Read + parse the configuration descriptor set.
static ra8_err_t	internal_enum_configure (uint8_t dev_addr, uint8_t cfg_value)
	SET_CONFIGURATION, best-effort GET_MAX_LUN, and pipe setup.
static void	internal_enum_fill_ids (const uint8_t *desc)
	Unpack VID/PID from a device descriptor into the snapshot.
static void	internal_enum_publish (uint8_t dev_addr, ra8_usb_hmsc_device_t *out_device)
	Publish a completed enumeration: snapshot, callback, out-copy.
static ra8_err_t	internal_enum_ladder (uint8_t *out_addr)
	Run the enumeration ladder: hunt, address, configure, pipes.
ra8_err_t	ra8_usb_hmsc_enumerate (ra8_usb_hmsc_device_t *out_device)
	Implementation of ra8_usb_hmsc_enumerate().

Variables
static const char *	s_tag = "USBHMSC"

Detailed Description

Native USB host-side MSC (Mass Storage Class) polled enumeration ladder.

Tag: [Ring 3 / HAL] {World: NS}

Sibling translation unit of ra8_usb_hmsc.c, split out purely to satisfy the per-file size cap. Holds the hardware-proven polled enumeration ladder (ra8_usb_hmsc_enumerate) and its internal_enum_* helpers: wait for the D+ attach, hunt the (reset, address) combination the device answers on, assign address 1, read + parse the configuration descriptor set, run SET_CONFIGURATION / GET_MAX_LUN, program the bulk pipes, and fire the attach callback. Every chapter-9 SETUP goes through ra8_usb_host_setup_request.

The singleton shadow state (g_usb_hmsc_state) lives in ra8_usb_hmsc.c and is shared with this TU through ra8_hal_internal.h.

Copyright: Copyright (c) 2026 Brighton Sikarskie SPDX-License-Identifier: MIT

Since: 0.1.0

Definition in file ra8_usb_hmsc_enum.c.

Enumeration Type Documentation

◆ ra8_usb_hmsc_enum_tune_t

enum ra8_usb_hmsc_enum_tune_t : uint32_t

Timing / retry tunables for the polled enumeration ladder.

Enumerator
k_ra8_hmsc_vbus_settle_ms	Supply settle before probing.
k_ra8_hmsc_attach_to_ms	Wait for the D+ pull-up.
k_ra8_hmsc_debounce_ms	Post-attach debounce (>=100 ms).
k_ra8_hmsc_reset_hold_ms	USB bus-reset hold (>=10 ms).
k_ra8_hmsc_recovery_ms	Post-reset recovery (TRSTRCY).
k_ra8_hmsc_addr_settle_ms	Post-SET_ADDRESS recovery.
k_ra8_hmsc_enum_tries	(reset? , addr) hunt attempts.
k_ra8_hmsc_no_reset_tries	Attempts before using bus reset.
k_ra8_hmsc_addr_alt_mask	Alternate addr 0..3 per attempt.
k_ra8_hmsc_cfg_buf_len	Full-configuration read buffer.
k_ra8_hmsc_attach_spin_limit	P10 iteration bound on the attach wait: the loop is primarily ms-bounded via ra8_time_ms, but if the tick is frozen (fake builds, SysTick masked) the spin cap guarantees termination.

Definition at line 49 of file ra8_usb_hmsc_enum.c.

◆ ra8_usb_hmsc_walk_off_t

enum ra8_usb_hmsc_walk_off_t : uint8_t

Descriptor-walk byte offsets and identity codes.

Enumerator
k_ra8_hmsc_off_dlen	Any descriptor: bLength.
k_ra8_hmsc_off_dtype	Any descriptor: bDescriptorType.
k_ra8_hmsc_off_iface_num	Interface: bInterfaceNumber.
k_ra8_hmsc_off_iface_class	Interface: bInterfaceClass.
k_ra8_hmsc_off_iface_sub	Interface: bInterfaceSubClass.
k_ra8_hmsc_off_iface_proto	Interface: bInterfaceProtocol.
k_ra8_hmsc_off_ep_addr	Endpoint: bEndpointAddress.
k_ra8_hmsc_off_ep_attr	Endpoint: bmAttributes.
k_ra8_hmsc_off_ep_mps	Endpoint: wMaxPacketSize LSB.
k_ra8_hmsc_off_cfg_total	Configuration: wTotalLength LSB.
k_ra8_hmsc_off_cfg_value	Configuration: bConfigValue.
k_ra8_hmsc_off_dev_vid	Device: idVendor LSB.
k_ra8_hmsc_off_dev_pid	Device: idProduct LSB.
k_ra8_hmsc_ep_dir_in_bit	bEndpointAddress direction bit.
k_ra8_hmsc_ep_num_mask	bEndpointAddress number field.
k_ra8_hmsc_ep_attr_mask	bmAttributes transfer-type mask.
k_ra8_hmsc_ep_attr_bulk	bmAttributes: bulk transfer.
k_ra8_hmsc_byte_bits	Bit width of one byte.

Definition at line 70 of file ra8_usb_hmsc_enum.c.

Function Documentation

◆ internal_enum_assign_addr()

ra8_err_t internal_enum_assign_addr ( uint8_t * dev_addr )

static

Move the device to address 1 when it answered at the default.

SET_CONFIGURATION is only legal from the Address state (sticks STALL it at the default address), so assign address 1, honour the set-address recovery, and retarget the DCP. Skipped when the hunt already found the device addressed.

Parameters

[in,out] dev_addr In: hunt result. Out: the operating address.

Returns: First failing step's error, or k_ra8_ok.

Return values

k_ra8_ok The DCP targets the operating address.

Precondition: internal_enum_hunt succeeded.; The bus is active (UACT on).

Postcondition: *dev_addr is non-zero on success.; Later transfers carry tokens to the new address.

Note: Blocking (one polled control transfer + settle).

Since: 0.1.0

Definition at line 206 of file ra8_usb_hmsc_enum.c.

References g_usb_hmsc_state, k_ra8_hmsc_addr_settle_ms, k_ra8_hmsc_assigned_address, k_ra8_hmsc_bm_std_dev_out, k_ra8_hmsc_breq_set_address, k_ra8_ok, ra8_delay_ms(), RA8_RETURN_ON_ERROR, ra8_usb_host_control_xfer(), ra8_usb_host_set_target(), and s_tag.

Referenced by internal_enum_ladder().

◆ internal_enum_configure()

ra8_err_t internal_enum_configure	(	uint8_t	dev_addr,
		uint8_t	cfg_value )

static

SET_CONFIGURATION, best-effort GET_MAX_LUN, and pipe setup.

Activates the parsed configuration (strict status), issues the class GET_MAX_LUN (devices may STALL it, which legally means LUN 0, so failures default to 0), then programs the bulk pipes against the snapshot endpoints at dev_addr.

Parameters

[in]	dev_addr	Address the device answers at.
[in]	cfg_value	bConfigurationValue to activate.

Returns: First failing step's error, or k_ra8_ok.

Return values

k_ra8_ok The device is configured and both pipes are ready.

Precondition: internal_enum_read_config filled the snapshot.; The DCP targets dev_addr.

Postcondition: The bulk pipes are configured (DATA0, parked NAK).; g_usb_hmsc_state.device.max_lun is filled (0 on GET_MAX_LUN failure).

Note: Blocking (polled control transfers).

Since: 0.1.0

Definition at line 417 of file ra8_usb_hmsc_enum.c.

References g_usb_hmsc_state, k_ra8_hmsc_bm_class_iface_in, k_ra8_hmsc_bm_std_dev_out, k_ra8_hmsc_breq_set_config, k_ra8_hmsc_get_max_lun_len, k_ra8_hmsc_pipe_bulk_in, k_ra8_hmsc_pipe_bulk_out, k_ra8_hmsc_req_get_max_lun, k_ra8_ok, RA8_RETURN_ON_ERROR, ra8_usb_host_control_xfer(), ra8_usb_host_pipe_setup(), and s_tag.

Referenced by internal_enum_ladder().

◆ internal_enum_fill_ids()

void internal_enum_fill_ids ( const uint8_t * desc )

static

Unpack VID/PID from a device descriptor into the snapshot.

Little-endian 16-bit fields at idVendor/idProduct.

Parameters

[in] desc Device descriptor bytes (18 valid bytes).

Precondition: desc is non-NULL and holds a device descriptor.; The snapshot was reset for this enumeration pass.

Postcondition: g_usb_hmsc_state.device.vendor_id / .product_id are filled.; desc is unmodified.

Note: Pure helper for ra8_usb_hmsc_enumerate.

Since: 0.1.0

Definition at line 477 of file ra8_usb_hmsc_enum.c.

References g_usb_hmsc_state, k_ra8_hmsc_byte_bits, k_ra8_hmsc_off_dev_pid, and k_ra8_hmsc_off_dev_vid.

Referenced by internal_enum_ladder().

◆ internal_enum_hunt()

ra8_err_t internal_enum_hunt	(	uint8_t *	desc,
		uint8_t *	out_addr )

static

Wait for a device to attach, then hunt for its address.

Waits for the D+ pull-up (LNST leaves SE0) plus the spec debounce, then tries each (reset?, address) combination: four gentle attempts at addresses 0..3 without touching the bus, then four more with a full bus reset (which also returns a previously addressed device to address 0). The first combination whose device-descriptor read returns all 18 bytes wins.

Parameters

[out]	desc	Receives the winning 18-byte device descriptor.
[out]	out_addr	Receives the address the device answered at.

Returns: Hunt outcome.

Return values

k_ra8_ok	The device answered.
k_ra8_err_hw_timeout	Nothing attached / nothing answered.

Precondition: ra8_usb_hmsc_init ran (host mode up, VBUS supplied).; ra8_time_init has run (the ladder uses millisecond delays).

Postcondition: On success the DCP targets *out_addr with UACT on.; On failure the bus state is whatever the last attempt left.

Note: Blocking; worst case a few seconds.

Since: 0.1.0

Definition at line 154 of file ra8_usb_hmsc_enum.c.

References g_usb_hmsc_state, internal_enum_read_dev_desc(), k_ra8_err_hw_timeout, k_ra8_hmsc_addr_alt_mask, k_ra8_hmsc_attach_spin_limit, k_ra8_hmsc_attach_to_ms, k_ra8_hmsc_debounce_ms, k_ra8_hmsc_enum_tries, k_ra8_hmsc_no_reset_tries, k_ra8_hmsc_recovery_ms, k_ra8_hmsc_reset_hold_ms, k_ra8_hmsc_vbus_settle_ms, k_ra8_ok, ra8_delay_ms(), ra8_time_ms(), ra8_usb_host_bus_reset(), ra8_usb_host_line_state(), ra8_usb_host_set_target(), and ra8_usb_host_set_uact().

Referenced by internal_enum_ladder().

◆ internal_enum_iface_is_msc()

bool internal_enum_iface_is_msc ( const uint8_t * d )

static

Test whether an interface descriptor is MSC SCSI Bulk-Only.

Matches class 0x08 (mass storage), subclass 0x06 (SCSI transparent), protocol 0x50 (Bulk-Only Transport) – the trio every consumer thumb drive reports.

Parameters

[in] d Interface descriptor bytes (9 valid bytes).

Returns: true when the interface is MSC SCSI BOT.

Return values

false Any of the three class fields differs.

Precondition: d is non-NULL and points at an interface descriptor.; The descriptor passed the walker's length check.

Postcondition: No state changes.; d is unmodified.

Note: Pure helper for internal_enum_walk_cfg.

Since: 0.1.0

Definition at line 283 of file ra8_usb_hmsc_enum.c.

References k_ra8_hmsc_class_msc, k_ra8_hmsc_off_iface_class, k_ra8_hmsc_off_iface_proto, k_ra8_hmsc_off_iface_sub, k_ra8_hmsc_protocol_bbb, and k_ra8_hmsc_subclass_scsi.

Referenced by internal_enum_walk_cfg().

◆ internal_enum_ladder()

ra8_err_t internal_enum_ladder ( uint8_t * out_addr )

static

Run the enumeration ladder: hunt, address, configure, pipes.

Waits for the attach, hunts the (reset, address) combination the device answers on, unpacks VID/PID, assigns address 1, parses + activates the configuration, and programs the bulk pipes.

Parameters

[out] out_addr Receives the address the device answers at.

Returns: First failing step's error, or k_ra8_ok.

Return values

k_ra8_ok The device is configured and both pipes are ready.

Precondition: ra8_usb_hmsc_init succeeded and VBUS reaches the device.; The snapshot was reset for this enumeration pass.

Postcondition: On success the snapshot carries IDs, endpoints, and max-LUN.; On failure the controller may need a fresh attach cycle.

Note: Helper for ra8_usb_hmsc_enumerate (statement-count split).

Since: 0.1.0

Definition at line 533 of file ra8_usb_hmsc_enum.c.

References internal_enum_assign_addr(), internal_enum_configure(), internal_enum_fill_ids(), internal_enum_hunt(), internal_enum_read_config(), k_ra8_hmsc_dev_desc_len, k_ra8_ok, RA8_RETURN_ON_ERROR, and s_tag.

Referenced by ra8_usb_hmsc_enumerate().

◆ internal_enum_note_endpoint()

void internal_enum_note_endpoint ( const uint8_t * d )

static

Record one bulk endpoint descriptor into the device snapshot.

Filters for bmAttributes == bulk and slots the endpoint into the IN or OUT position (first match wins) with its wMaxPacketSize.

Parameters

[in] d Pointer to an endpoint descriptor.

Precondition: d points at a descriptor with bDescriptorType ENDPOINT.; The unfilled g_usb_hmsc_state.device endpoint slots are zero.

Postcondition: A matching bulk endpoint is recorded once.; Non-bulk endpoints leave the snapshot untouched.

Note: Pure helper for the config-descriptor walk.

Since: 0.1.0

Definition at line 242 of file ra8_usb_hmsc_enum.c.

References g_usb_hmsc_state, k_ra8_hmsc_byte_bits, k_ra8_hmsc_ep_attr_bulk, k_ra8_hmsc_ep_attr_mask, k_ra8_hmsc_ep_dir_in_bit, k_ra8_hmsc_ep_num_mask, k_ra8_hmsc_off_ep_addr, k_ra8_hmsc_off_ep_attr, and k_ra8_hmsc_off_ep_mps.

Referenced by internal_enum_walk_cfg().

◆ internal_enum_publish()

void internal_enum_publish	(	uint8_t	dev_addr,
		ra8_usb_hmsc_device_t *	out_device )

static

Publish a completed enumeration: snapshot, callback, out-copy.

Stores the address, flips the attached flag, fires the registered attach callback, and copies the snapshot to the caller.

Parameters

[in]	dev_addr	Address the device answers at.
[out]	out_device	Caller's snapshot copy (may be NULL).

Precondition: The bulk pipes are configured and SCSI calls may follow.; The snapshot carries VID/PID, endpoints, and max-LUN.

Postcondition: g_usb_hmsc_state.attached is true; the callback (if any) has fired.; *out_device holds the snapshot when out_device is non-NULL.

Note: Helper for ra8_usb_hmsc_enumerate.

Since: 0.1.0

Definition at line 503 of file ra8_usb_hmsc_enum.c.

References g_usb_hmsc_state.

Referenced by ra8_usb_hmsc_enumerate().

◆ internal_enum_read_config()

ra8_err_t internal_enum_read_config ( uint8_t * out_cfg_value )

static

Read + parse the configuration descriptor set.

Reads the 9-byte header for wTotalLength + bConfigurationValue, re-reads the full set (clamped to the local buffer), and walks it for the MSC interface and bulk endpoints.

Parameters

[out] out_cfg_value Receives bConfigurationValue.

Returns: First failing step's error, or k_ra8_ok.

Return values

k_ra8_ok The device snapshot carries the MSC endpoints.

Precondition: The device is addressed and answering control reads.; out_cfg_value is non-NULL.

Postcondition: On success the snapshot endpoints + interface are filled.; *out_cfg_value holds the value SET_CONFIGURATION needs.

Note: Blocking (two polled control reads).

Since: 0.1.0

Definition at line 367 of file ra8_usb_hmsc_enum.c.

References g_usb_hmsc_state, internal_enum_walk_cfg(), k_ra8_hmsc_bm_std_dev_in, k_ra8_hmsc_breq_get_descriptor, k_ra8_hmsc_byte_bits, k_ra8_hmsc_cfg_buf_len, k_ra8_hmsc_cfg_desc_len, k_ra8_hmsc_desc_configuration, k_ra8_hmsc_off_cfg_total, k_ra8_hmsc_off_cfg_value, RA8_RETURN_ON_ERROR, ra8_usb_host_control_xfer(), s_tag, and ra8_usb_setup_t::w_length.

Referenced by internal_enum_ladder().

◆ internal_enum_read_dev_desc()

ra8_err_t internal_enum_read_dev_desc ( uint8_t * desc )

static

Read the 18-byte device descriptor over the polled control engine.

GET_DESCRIPTOR(DEVICE) at whatever address the DCP currently targets; requires the full 18 bytes back.

Parameters

[out] desc Receives the descriptor (18 bytes).

Returns: Read outcome.

Return values

k_ra8_ok	All 18 bytes arrived.
k_ra8_err_hw_error	A short descriptor came back.

Precondition: The bus is reset and UACT is on.; desc holds at least 18 bytes.

Postcondition: desc carries the device descriptor on success.; No state is modified.

Note: Blocking (polled control transfer).

Since: 0.1.0

Definition at line 109 of file ra8_usb_hmsc_enum.c.

References g_usb_hmsc_state, k_ra8_err_hw_error, k_ra8_hmsc_bm_std_dev_in, k_ra8_hmsc_breq_get_descriptor, k_ra8_hmsc_byte_bits, k_ra8_hmsc_desc_device, k_ra8_hmsc_dev_desc_len, k_ra8_ok, RA8_RETURN_ON_ERROR, ra8_usb_host_control_xfer(), and s_tag.

Referenced by internal_enum_hunt().

◆ internal_enum_walk_cfg()

ra8_err_t internal_enum_walk_cfg	(	const uint8_t *	cfg,
		uint16_t	len )

static

Walk a configuration blob for the MSC interface + bulk endpoints.

Strides descriptor-by-descriptor; an interface descriptor with class 0x08 / subclass 0x06 / protocol 0x50 opens the MSC scope, and the bulk endpoints inside it populate the device snapshot.

Parameters

[in]	cfg	Configuration descriptor bytes.
[in]	len	Valid byte count in `cfg`.

Returns: Walk outcome.

Return values

k_ra8_ok	Both bulk endpoints were found.
k_ra8_err_hw_error	No MSC bulk endpoint pair in the blob.

Precondition: cfg is non-NULL with len valid bytes.; The device snapshot endpoint slots start zeroed.

Postcondition: On k_ra8_ok the snapshot carries eps, max packets, and iface.; cfg is unmodified.

Note: Pure helper for internal_enum_read_config.

Since: 0.1.0

Definition at line 317 of file ra8_usb_hmsc_enum.c.

References g_usb_hmsc_state, internal_enum_iface_is_msc(), internal_enum_note_endpoint(), k_ra8_err_hw_error, k_ra8_hmsc_desc_endpoint, k_ra8_hmsc_desc_interface, k_ra8_hmsc_off_dlen, k_ra8_hmsc_off_dtype, k_ra8_hmsc_off_iface_num, and k_ra8_ok.

Referenced by internal_enum_read_config().

◆ ra8_usb_hmsc_enumerate()

ra8_err_t ra8_usb_hmsc_enumerate ( ra8_usb_hmsc_device_t * out_device )

nodiscard

Implementation of ra8_usb_hmsc_enumerate().

Enumerate the attached MSC device end to end (polled).

See the public header for the documented contract; runs the hardware-proven polled ladder: attach wait, (reset, address) hunt, address assignment, configuration parse + activate, GET_MAX_LUN, bulk pipe setup, then fires the attach callback.

Parameters

[out] out_device See header (may be NULL).

Returns: Result code.

Return values

k_ra8_ok Device enumerated; SCSI calls may follow.

Precondition: ra8_usb_hmsc_init succeeded and VBUS reaches the device.; ra8_time_init has run.

Postcondition: On success g_usb_hmsc_state.attached is true and the snapshot is filled.; The registered attach callback (if any) has fired.

Note: Blocking; bounded by the ladder timeouts.

Since: 0.1.0

Definition at line 566 of file ra8_usb_hmsc_enum.c.

References g_usb_hmsc_state, internal_enum_ladder(), internal_enum_publish(), k_ra8_err_invalid_state, and k_ra8_ok.

Referenced by fileops_run_ladder(), microsd_host_enumerate(), mlun_host_enumerate(), ospirw_host_enumerate(), selftest_host_enumerate(), selftest_host_enumerate(), selftest_host_enumerate(), selftest_host_enumerate(), selftest_host_enumerate(), and wlun_host_enumerate().

Variable Documentation

◆ s_tag

const char* s_tag = "USBHMSC"

static

Definition at line 38 of file ra8_usb_hmsc_enum.c.

Enumerations

Functions

Variables

Detailed Description

Enumeration Type Documentation

◆ ra8_usb_hmsc_enum_tune_t

◆ ra8_usb_hmsc_walk_off_t

Function Documentation

◆ internal_enum_assign_addr()

◆ internal_enum_configure()

◆ internal_enum_fill_ids()

◆ internal_enum_hunt()

◆ internal_enum_iface_is_msc()

◆ internal_enum_ladder()

◆ internal_enum_note_endpoint()

◆ internal_enum_publish()

◆ internal_enum_read_config()

◆ internal_enum_read_dev_desc()

◆ internal_enum_walk_cfg()

◆ ra8_usb_hmsc_enumerate()

Variable Documentation

◆ s_tag