mirror of
https://github.com/gdsports/USBHost_t36
synced 2024-11-21 16:45:04 -05:00
Convert to C++ classes
This commit is contained in:
parent
2a2f745dc1
commit
dc87eeaaf6
100
USBHost.h
100
USBHost.h
@ -26,11 +26,19 @@
|
||||
|
||||
#include <stdint.h>
|
||||
|
||||
/************************************************/
|
||||
/* Data Structure Definitions */
|
||||
/************************************************/
|
||||
|
||||
class USBHost;
|
||||
class USBHostDriver;
|
||||
typedef struct Device_struct Device_t;
|
||||
typedef struct Pipe_struct Pipe_t;
|
||||
typedef struct Transfer_struct Transfer_t;
|
||||
|
||||
|
||||
// setup_t holds the 8 byte USB SETUP packet data.
|
||||
// These unions & structs allow convenient access to
|
||||
// the setup fields.
|
||||
typedef union {
|
||||
struct {
|
||||
union {
|
||||
@ -50,7 +58,7 @@ typedef union {
|
||||
};
|
||||
} setup_t;
|
||||
|
||||
|
||||
// Device_t holds all the information about a USB device
|
||||
struct Device_struct {
|
||||
Pipe_t *control_pipe;
|
||||
Device_t *next;
|
||||
@ -68,6 +76,8 @@ struct Device_struct {
|
||||
uint16_t LanguageID;
|
||||
};
|
||||
|
||||
// Pipe_t holes all information about each USB endpoint/pipe
|
||||
// The first half is an EHCI QH structure for the pipe.
|
||||
struct Pipe_struct {
|
||||
// Queue Head (QH), EHCI page 46-50
|
||||
struct { // must be aligned to 32 byte boundary
|
||||
@ -87,7 +97,14 @@ struct Pipe_struct {
|
||||
void (*callback_function)(const Transfer_t *);
|
||||
};
|
||||
|
||||
|
||||
// Transfer_t represents a single transaction on the USB bus.
|
||||
// The first portion is an EHCI qTD structure. Transfer_t are
|
||||
// allocated as-needed from a memory pool, loaded with pointers
|
||||
// to the actual data buffers, linked into a followup list,
|
||||
// and placed on ECHI Queue Heads. When the ECHI interrupt
|
||||
// occurs, the followup lists are used to find the Transfer_t
|
||||
// in memory. Callbacks are made, and then the Transfer_t are
|
||||
// returned to the memory pool.
|
||||
struct Transfer_struct {
|
||||
// Queue Element Transfer Descriptor (qTD), EHCI pg 40-45
|
||||
struct { // must be aligned to 32 byte boundary
|
||||
@ -96,69 +113,56 @@ struct Transfer_struct {
|
||||
volatile uint32_t token;
|
||||
volatile uint32_t buffer[5];
|
||||
} qtd;
|
||||
// linked list of queued, not-yet-completed transfers
|
||||
// Linked list of queued, not-yet-completed transfers
|
||||
Transfer_t *next_followup;
|
||||
Transfer_t *prev_followup;
|
||||
// data to be used by callback function
|
||||
// Data to be used by callback function. When a group
|
||||
// of Transfer_t are created, these fields and the
|
||||
// interrupt-on-complete bit in the qTD token are only
|
||||
// set in the last Transfer_t of the list.
|
||||
Pipe_t *pipe;
|
||||
void *buffer;
|
||||
uint32_t length;
|
||||
uint32_t unused[3];
|
||||
};
|
||||
|
||||
void begin();
|
||||
Pipe_t * new_Pipe(Device_t *dev, uint32_t type, uint32_t endpoint, uint32_t direction,
|
||||
uint32_t max_packet_len);
|
||||
bool new_Transfer(Pipe_t *pipe, void *buffer, uint32_t len);
|
||||
bool followup_Transfer(Transfer_t *transfer);
|
||||
void add_to_async_followup_list(Transfer_t *first, Transfer_t *last);
|
||||
void remove_from_async_followup_list(Transfer_t *transfer);
|
||||
void add_to_periodic_followup_list(Transfer_t *first, Transfer_t *last);
|
||||
void remove_from_periodic_followup_list(Transfer_t *transfer);
|
||||
|
||||
|
||||
Device_t * new_Device(uint32_t speed, uint32_t hub_addr, uint32_t hub_port);
|
||||
void enumeration(const Transfer_t *transfer);
|
||||
void mk_setup(setup_t &s, uint32_t bmRequestType, uint32_t bRequest,
|
||||
uint32_t wValue, uint32_t wIndex, uint32_t wLength);
|
||||
uint32_t assign_addr(void);
|
||||
void pipe_set_maxlen(Pipe_t *pipe, uint32_t maxlen);
|
||||
void pipe_set_addr(Pipe_t *pipe, uint32_t addr);
|
||||
uint32_t pipe_get_addr(Pipe_t *pipe);
|
||||
|
||||
|
||||
|
||||
void init_Device_Pipe_Transfer_memory(void);
|
||||
Device_t * allocate_Device(void);
|
||||
void free_Device(Device_t *q);
|
||||
Pipe_t * allocate_Pipe(void);
|
||||
void free_Pipe(Pipe_t *q);
|
||||
Transfer_t * allocate_Transfer(void);
|
||||
void free_Transfer(Transfer_t *q);
|
||||
|
||||
void print(const Transfer_t *transfer);
|
||||
void print(const Transfer_t *first, const Transfer_t *last);
|
||||
void print_token(uint32_t token);
|
||||
void print(const Pipe_t *pipe);
|
||||
void print_hexbytes(const void *ptr, uint32_t len);
|
||||
void print(const char *s);
|
||||
void print(const char *s, int num);
|
||||
|
||||
/************************************************/
|
||||
/* Main USB EHCI Controller */
|
||||
/************************************************/
|
||||
|
||||
class USBHost {
|
||||
public:
|
||||
static void begin();
|
||||
protected:
|
||||
static Pipe_t * new_Pipe(Device_t *dev, uint32_t type, uint32_t endpoint,
|
||||
uint32_t direction, uint32_t max_packet_len);
|
||||
static bool new_Transfer(Pipe_t *pipe, void *buffer, uint32_t len);
|
||||
static Device_t * new_Device(uint32_t speed, uint32_t hub_addr, uint32_t hub_port);
|
||||
static void enumeration(const Transfer_t *transfer);
|
||||
private:
|
||||
static void isr();
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
static void init_Device_Pipe_Transfer_memory(void);
|
||||
static Device_t * allocate_Device(void);
|
||||
static void free_Device(Device_t *q);
|
||||
static Pipe_t * allocate_Pipe(void);
|
||||
static void free_Pipe(Pipe_t *q);
|
||||
static Transfer_t * allocate_Transfer(void);
|
||||
static void free_Transfer(Transfer_t *q);
|
||||
protected:
|
||||
static void print(const Transfer_t *transfer);
|
||||
static void print(const Transfer_t *first, const Transfer_t *last);
|
||||
static void print_token(uint32_t token);
|
||||
static void print(const Pipe_t *pipe);
|
||||
static void print_hexbytes(const void *ptr, uint32_t len);
|
||||
static void print(const char *s);
|
||||
static void print(const char *s, int num);
|
||||
};
|
||||
|
||||
|
||||
/************************************************/
|
||||
/* USB Device Drivers */
|
||||
/************************************************/
|
||||
|
||||
class USBHostDriver : public USBHost {
|
||||
public:
|
||||
virtual bool claim_device(Device_t *device) {
|
||||
|
48
ehci.cpp
48
ehci.cpp
@ -24,21 +24,30 @@
|
||||
#include <Arduino.h>
|
||||
#include "USBHost.h"
|
||||
|
||||
|
||||
uint32_t periodictable[32] __attribute__ ((aligned(4096), used));
|
||||
uint8_t port_state;
|
||||
static uint32_t periodictable[32] __attribute__ ((aligned(4096), used));
|
||||
static uint8_t port_state;
|
||||
#define PORT_STATE_DISCONNECTED 0
|
||||
#define PORT_STATE_DEBOUNCE 1
|
||||
#define PORT_STATE_RESET 2
|
||||
#define PORT_STATE_RECOVERY 3
|
||||
#define PORT_STATE_ACTIVE 4
|
||||
Device_t *rootdev=NULL;
|
||||
Transfer_t *async_followup_first=NULL;
|
||||
Transfer_t *async_followup_last=NULL;
|
||||
Transfer_t *periodic_followup_first=NULL;
|
||||
Transfer_t *periodic_followup_last=NULL;
|
||||
static Device_t *rootdev=NULL;
|
||||
static Transfer_t *async_followup_first=NULL;
|
||||
static Transfer_t *async_followup_last=NULL;
|
||||
static Transfer_t *periodic_followup_first=NULL;
|
||||
static Transfer_t *periodic_followup_last=NULL;
|
||||
|
||||
void begin()
|
||||
|
||||
static void isr();
|
||||
static void init_qTD(volatile Transfer_t *t, void *buf, uint32_t len,
|
||||
uint32_t pid, uint32_t data01, bool irq);
|
||||
static bool followup_Transfer(Transfer_t *transfer);
|
||||
static void add_to_async_followup_list(Transfer_t *first, Transfer_t *last);
|
||||
static void remove_from_async_followup_list(Transfer_t *transfer);
|
||||
static void add_to_periodic_followup_list(Transfer_t *first, Transfer_t *last);
|
||||
static void remove_from_periodic_followup_list(Transfer_t *transfer);
|
||||
|
||||
void USBHost::begin()
|
||||
{
|
||||
// Teensy 3.6 has USB host power controlled by PTE6
|
||||
PORTE_PCR6 = PORT_PCR_MUX(1);
|
||||
@ -139,6 +148,7 @@ void begin()
|
||||
Serial.println((uint32_t)periodictable, HEX);
|
||||
|
||||
// enable interrupts, after this point interruts to all the work
|
||||
attachInterruptVector(IRQ_USBHS, isr);
|
||||
NVIC_ENABLE_IRQ(IRQ_USBHS);
|
||||
USBHS_USBINTR = USBHS_USBINTR_PCE | USBHS_USBINTR_TIE0;
|
||||
USBHS_USBINTR |= USBHS_USBINTR_UEE | USBHS_USBINTR_SEE;
|
||||
@ -167,7 +177,7 @@ void begin()
|
||||
// PORT_STATE_ACTIVE 4
|
||||
|
||||
|
||||
void usbhs_isr()
|
||||
void USBHost::isr()
|
||||
{
|
||||
uint32_t stat = USBHS_USBSTS;
|
||||
USBHS_USBSTS = stat; // clear pending interrupts
|
||||
@ -316,8 +326,8 @@ static uint32_t QH_capabilities2(uint32_t high_bw_mult, uint32_t hub_port_number
|
||||
// Create a new pipe. It's QH is added to the async or periodic schedule,
|
||||
// and a halt qTD is added to the QH, so we can grow the qTD list later.
|
||||
//
|
||||
Pipe_t * new_Pipe(Device_t *dev, uint32_t type, uint32_t endpoint, uint32_t direction,
|
||||
uint32_t max_packet_len)
|
||||
Pipe_t * USBHost::new_Pipe(Device_t *dev, uint32_t type, uint32_t endpoint,
|
||||
uint32_t direction, uint32_t max_packet_len)
|
||||
{
|
||||
Pipe_t *pipe;
|
||||
Transfer_t *halt;
|
||||
@ -386,7 +396,7 @@ Pipe_t * new_Pipe(Device_t *dev, uint32_t type, uint32_t endpoint, uint32_t dire
|
||||
// data01 value of DATA0/DATA1 toggle on 1st packet
|
||||
// irq whether to generate an interrupt when transfer complete
|
||||
//
|
||||
void init_qTD(volatile Transfer_t *t, void *buf, uint32_t len,
|
||||
static void init_qTD(volatile Transfer_t *t, void *buf, uint32_t len,
|
||||
uint32_t pid, uint32_t data01, bool irq)
|
||||
{
|
||||
t->qtd.alt_next = 1; // 1=terminate
|
||||
@ -404,7 +414,7 @@ void init_qTD(volatile Transfer_t *t, void *buf, uint32_t len,
|
||||
|
||||
// Create a Transfer and queue it
|
||||
//
|
||||
bool new_Transfer(Pipe_t *pipe, void *buffer, uint32_t len)
|
||||
bool USBHost::new_Transfer(Pipe_t *pipe, void *buffer, uint32_t len)
|
||||
{
|
||||
Serial.println("new_Transfer");
|
||||
Transfer_t *transfer = allocate_Transfer();
|
||||
@ -500,7 +510,7 @@ bool new_Transfer(Pipe_t *pipe, void *buffer, uint32_t len)
|
||||
return true;
|
||||
}
|
||||
|
||||
bool followup_Transfer(Transfer_t *transfer)
|
||||
static bool followup_Transfer(Transfer_t *transfer)
|
||||
{
|
||||
Serial.print(" Followup ");
|
||||
Serial.println((uint32_t)transfer, HEX);
|
||||
@ -521,7 +531,7 @@ bool followup_Transfer(Transfer_t *transfer)
|
||||
return false;
|
||||
}
|
||||
|
||||
void add_to_async_followup_list(Transfer_t *first, Transfer_t *last)
|
||||
static void add_to_async_followup_list(Transfer_t *first, Transfer_t *last)
|
||||
{
|
||||
last->next_followup = NULL; // always add to end of list
|
||||
if (async_followup_last == NULL) {
|
||||
@ -534,7 +544,7 @@ void add_to_async_followup_list(Transfer_t *first, Transfer_t *last)
|
||||
async_followup_last = last;
|
||||
}
|
||||
|
||||
void remove_from_async_followup_list(Transfer_t *transfer)
|
||||
static void remove_from_async_followup_list(Transfer_t *transfer)
|
||||
{
|
||||
Transfer_t *next = transfer->next_followup;
|
||||
Transfer_t *prev = transfer->prev_followup;
|
||||
@ -550,7 +560,7 @@ void remove_from_async_followup_list(Transfer_t *transfer)
|
||||
}
|
||||
}
|
||||
|
||||
void add_to_periodic_followup_list(Transfer_t *first, Transfer_t *last)
|
||||
static void add_to_periodic_followup_list(Transfer_t *first, Transfer_t *last)
|
||||
{
|
||||
last->next_followup = NULL; // always add to end of list
|
||||
if (periodic_followup_last == NULL) {
|
||||
@ -563,7 +573,7 @@ void add_to_periodic_followup_list(Transfer_t *first, Transfer_t *last)
|
||||
periodic_followup_last = last;
|
||||
}
|
||||
|
||||
void remove_from_periodic_followup_list(Transfer_t *transfer)
|
||||
static void remove_from_periodic_followup_list(Transfer_t *transfer)
|
||||
{
|
||||
Transfer_t *next = transfer->next_followup;
|
||||
Transfer_t *prev = transfer->prev_followup;
|
||||
|
@ -25,19 +25,19 @@
|
||||
#include "USBHost.h"
|
||||
|
||||
|
||||
void mk_setup(setup_t &s, uint32_t bmRequestType, uint32_t bRequest,
|
||||
uint32_t wValue, uint32_t wIndex, uint32_t wLength)
|
||||
{
|
||||
s.word1 = bmRequestType | (bRequest << 8) | (wValue << 16);
|
||||
s.word2 = wIndex | (wLength << 16);
|
||||
}
|
||||
|
||||
static uint8_t enumbuf[256] __attribute__ ((aligned(16)));
|
||||
|
||||
|
||||
static void mk_setup(setup_t &s, uint32_t bmRequestType, uint32_t bRequest,
|
||||
uint32_t wValue, uint32_t wIndex, uint32_t wLength);
|
||||
static uint32_t assign_addr(void);
|
||||
static void pipe_set_maxlen(Pipe_t *pipe, uint32_t maxlen);
|
||||
static void pipe_set_addr(Pipe_t *pipe, uint32_t addr);
|
||||
|
||||
|
||||
// Create a new device and begin the enumeration process
|
||||
//
|
||||
Device_t * new_Device(uint32_t speed, uint32_t hub_addr, uint32_t hub_port)
|
||||
Device_t * USBHost::new_Device(uint32_t speed, uint32_t hub_addr, uint32_t hub_port)
|
||||
{
|
||||
Device_t *dev;
|
||||
|
||||
@ -71,7 +71,7 @@ Device_t * new_Device(uint32_t speed, uint32_t hub_addr, uint32_t hub_port)
|
||||
|
||||
|
||||
|
||||
void enumeration(const Transfer_t *transfer)
|
||||
void USBHost::enumeration(const Transfer_t *transfer)
|
||||
{
|
||||
uint32_t len;
|
||||
|
||||
@ -203,28 +203,35 @@ void enumeration(const Transfer_t *transfer)
|
||||
}
|
||||
}
|
||||
|
||||
uint32_t assign_addr(void)
|
||||
static uint32_t assign_addr(void)
|
||||
{
|
||||
return 29; // TODO: when multiple devices, assign a unique address
|
||||
}
|
||||
|
||||
void pipe_set_maxlen(Pipe_t *pipe, uint32_t maxlen)
|
||||
static void mk_setup(setup_t &s, uint32_t bmRequestType, uint32_t bRequest,
|
||||
uint32_t wValue, uint32_t wIndex, uint32_t wLength)
|
||||
{
|
||||
s.word1 = bmRequestType | (bRequest << 8) | (wValue << 16);
|
||||
s.word2 = wIndex | (wLength << 16);
|
||||
}
|
||||
|
||||
static void pipe_set_maxlen(Pipe_t *pipe, uint32_t maxlen)
|
||||
{
|
||||
Serial.print("pipe_set_maxlen ");
|
||||
Serial.println(maxlen);
|
||||
pipe->qh.capabilities[0] = (pipe->qh.capabilities[0] & 0x8000FFFF) | (maxlen << 16);
|
||||
}
|
||||
|
||||
void pipe_set_addr(Pipe_t *pipe, uint32_t addr)
|
||||
static void pipe_set_addr(Pipe_t *pipe, uint32_t addr)
|
||||
{
|
||||
Serial.print("pipe_set_addr ");
|
||||
Serial.println(addr);
|
||||
pipe->qh.capabilities[0] = (pipe->qh.capabilities[0] & 0xFFFFFF80) | addr;
|
||||
}
|
||||
|
||||
uint32_t pipe_get_addr(Pipe_t *pipe)
|
||||
{
|
||||
return pipe->qh.capabilities[0] & 0xFFFFFF80;
|
||||
}
|
||||
//static uint32_t pipe_get_addr(Pipe_t *pipe)
|
||||
//{
|
||||
// return pipe->qh.capabilities[0] & 0xFFFFFF80;
|
||||
//}
|
||||
|
||||
|
||||
|
@ -23,6 +23,8 @@
|
||||
|
||||
#include "USBHost.h"
|
||||
|
||||
USBHost myusb;
|
||||
|
||||
void setup()
|
||||
{
|
||||
// Test board has a USB data mux (this won't be on final Teensy 3.6)
|
||||
@ -34,7 +36,7 @@ void setup()
|
||||
while (!Serial) ; // wait for Arduino Serial Monitor
|
||||
Serial.println("USB Host Testing");
|
||||
|
||||
begin();
|
||||
myusb.begin();
|
||||
|
||||
delay(25);
|
||||
Serial.println("Plug in device...");
|
||||
|
20
memory.cpp
20
memory.cpp
@ -31,11 +31,11 @@ static Device_t memory_Device[3];
|
||||
static Pipe_t memory_Pipe[6] __attribute__ ((aligned(64)));
|
||||
static Transfer_t memory_Transfer[24] __attribute__ ((aligned(64)));
|
||||
|
||||
Device_t * free_Device_list = NULL;
|
||||
Pipe_t * free_Pipe_list = NULL;
|
||||
Transfer_t * free_Transfer_list = NULL;
|
||||
static Device_t * free_Device_list = NULL;
|
||||
static Pipe_t * free_Pipe_list = NULL;
|
||||
static Transfer_t * free_Transfer_list = NULL;
|
||||
|
||||
void init_Device_Pipe_Transfer_memory(void)
|
||||
void USBHost::init_Device_Pipe_Transfer_memory(void)
|
||||
{
|
||||
Device_t *end_device = memory_Device + sizeof(memory_Device)/sizeof(Device_t);
|
||||
for (Device_t *device = memory_Device; device < end_device; device++) {
|
||||
@ -51,40 +51,40 @@ void init_Device_Pipe_Transfer_memory(void)
|
||||
}
|
||||
}
|
||||
|
||||
Device_t * allocate_Device(void)
|
||||
Device_t * USBHost::allocate_Device(void)
|
||||
{
|
||||
Device_t *device = free_Device_list;
|
||||
if (device) free_Device_list = *(Device_t **)device;
|
||||
return device;
|
||||
}
|
||||
|
||||
void free_Device(Device_t *device)
|
||||
void USBHost::free_Device(Device_t *device)
|
||||
{
|
||||
*(Device_t **)device = free_Device_list;
|
||||
free_Device_list = device;
|
||||
}
|
||||
|
||||
Pipe_t * allocate_Pipe(void)
|
||||
Pipe_t * USBHost::allocate_Pipe(void)
|
||||
{
|
||||
Pipe_t *pipe = free_Pipe_list;
|
||||
if (pipe) free_Pipe_list = *(Pipe_t **)pipe;
|
||||
return pipe;
|
||||
}
|
||||
|
||||
void free_Pipe(Pipe_t *pipe)
|
||||
void USBHost::free_Pipe(Pipe_t *pipe)
|
||||
{
|
||||
*(Pipe_t **)pipe = free_Pipe_list;
|
||||
free_Pipe_list = pipe;
|
||||
}
|
||||
|
||||
Transfer_t * allocate_Transfer(void)
|
||||
Transfer_t * USBHost::allocate_Transfer(void)
|
||||
{
|
||||
Transfer_t *transfer = free_Transfer_list;
|
||||
if (transfer) free_Transfer_list = *(Transfer_t **)transfer;
|
||||
return transfer;
|
||||
}
|
||||
|
||||
void free_Transfer(Transfer_t *transfer)
|
||||
void USBHost::free_Transfer(Transfer_t *transfer)
|
||||
{
|
||||
*(Transfer_t **)transfer = free_Transfer_list;
|
||||
free_Transfer_list = transfer;
|
||||
|
14
print.cpp
14
print.cpp
@ -25,7 +25,7 @@
|
||||
#include "USBHost.h"
|
||||
|
||||
|
||||
void print(const Transfer_t *transfer)
|
||||
void USBHost::print(const Transfer_t *transfer)
|
||||
{
|
||||
if (!((uint32_t)transfer & 0xFFFFFFE0)) return;
|
||||
Serial.print("Transfer @ ");
|
||||
@ -44,7 +44,7 @@ void print(const Transfer_t *transfer)
|
||||
Serial.println();
|
||||
}
|
||||
|
||||
void print(const Transfer_t *first, const Transfer_t *last)
|
||||
void USBHost::print(const Transfer_t *first, const Transfer_t *last)
|
||||
{
|
||||
Serial.print("Transfer Followup List ");
|
||||
Serial.print((uint32_t)first, HEX);
|
||||
@ -66,7 +66,7 @@ void print(const Transfer_t *first, const Transfer_t *last)
|
||||
}
|
||||
}
|
||||
|
||||
void print_token(uint32_t token)
|
||||
void USBHost::print_token(uint32_t token)
|
||||
{
|
||||
switch ((token >> 8) & 3) {
|
||||
case 0:
|
||||
@ -85,7 +85,7 @@ void print_token(uint32_t token)
|
||||
}
|
||||
}
|
||||
|
||||
void print(const Pipe_t *pipe)
|
||||
void USBHost::print(const Pipe_t *pipe)
|
||||
{
|
||||
if (!((uint32_t)pipe & 0xFFFFFFE0)) return;
|
||||
Serial.print("Pipe ");
|
||||
@ -126,7 +126,7 @@ void print(const Pipe_t *pipe)
|
||||
}
|
||||
|
||||
|
||||
void print_hexbytes(const void *ptr, uint32_t len)
|
||||
void USBHost::print_hexbytes(const void *ptr, uint32_t len)
|
||||
{
|
||||
if (ptr == NULL || len == 0) return;
|
||||
const uint8_t *p = (const uint8_t *)ptr;
|
||||
@ -138,13 +138,13 @@ void print_hexbytes(const void *ptr, uint32_t len)
|
||||
Serial.println();
|
||||
}
|
||||
|
||||
void print(const char *s)
|
||||
void USBHost::print(const char *s)
|
||||
{
|
||||
Serial.println(s);
|
||||
delay(10);
|
||||
}
|
||||
|
||||
void print(const char *s, int num)
|
||||
void USBHost::print(const char *s, int num)
|
||||
{
|
||||
Serial.print(s);
|
||||
Serial.println(num);
|
||||
|
Loading…
Reference in New Issue
Block a user