usbdcore_mpc8xx.c

U-boot源码 ARM7启动代码

	 * TODO: fit a pull-up resistor to drive SE0 for > 2.5us
	 */

	if (udc_state != STATE_ERROR) {
		udc_state = STATE_READY;
		usbp->usmod |= USMOD_EN;
	}
}

/* udc_disconnect
 *
 * Disconnect is not used but, is included for completeness
 */
void udc_disconnect (void)
{
	/* Disable pull-up resistor on D-
	 * TODO: fix a pullup resistor to control this
	 */

	if (udc_state != STATE_ERROR) {
		udc_state = STATE_NOT_READY;
	}
	usbp->usmod &= ~USMOD_EN;
}

/* udc_enable
 *
 * Grab an EP0 URB, register interest in a subset of USB events
 */
void udc_enable (struct usb_device_instance *device)
{
	if (udc_state == STATE_ERROR) {
		return;
	}

	udc_device = device;

	if (!ep_ref[0].urb) {
		ep_ref[0].urb = usbd_alloc_urb (device, device->bus->endpoint_array);
	}

	/* Register interest in all events except SOF, enable transceiver */
	usbp->usber = 0x03FF;
	usbp->usbmr = 0x02F7;

	return;
}

/* udc_disable
 *
 * disable the currently hooked device
 */
void udc_disable (void)
{
	int i = 0;

	if (udc_state == STATE_ERROR) {
		DBG ("Won't disable UDC. udc_state==STATE_ERROR !\n");
		return;
	}

	udc_device = 0;

	for (; i < MAX_ENDPOINTS; i++) {
		if (ep_ref[i].urb) {
			usbd_dealloc_urb (ep_ref[i].urb);
			ep_ref[i].urb = 0;
		}
	}

	usbp->usbmr = 0x00;
	usbp->usmod = ~USMOD_EN;
	udc_state = STATE_NOT_READY;
}

/* udc_startup_events
 *
 * Enable the specified device
 */
void udc_startup_events (struct usb_device_instance *device)
{
	udc_enable (device);
	if (udc_state == STATE_READY) {
		usbd_device_event_irq (device, DEVICE_CREATE, 0);
	}
}

/* udc_set_nak
 *
 * Allow upper layers to signal lower layers should not accept more RX data
 *
 */
void udc_set_nak (int epid)
{
	if (epid) {
		mpc8xx_udc_set_nak (epid);
	}
}

/* udc_unset_nak
 *
 * Suspend sending of NAK tokens for DATA OUT tokens on a given endpoint.
 * Switch off NAKing on this endpoint to accept more data output from host.
 *
 */
void udc_unset_nak (int epid)
{
	if (epid > MAX_ENDPOINTS) {
		return;
	}

	if (usbp->usep[epid] & (USEP_THS_NAK | USEP_RHS_NAK)) {
		usbp->usep[epid] &= ~(USEP_THS_NAK | USEP_RHS_NAK);
		__asm__ ("eieio");
	}
}

/******************************************************************************
			      Static Linkage
******************************************************************************/

/* udc_state_transition_up
 * udc_state_transition_down
 *
 * Helper functions to implement device state changes.	The device states and
 * the events that transition between them are:
 *
 *				STATE_ATTACHED
 *				||	/\
 *				\/	||
 *	DEVICE_HUB_CONFIGURED			DEVICE_HUB_RESET
 *				||	/\
 *				\/	||
 *				STATE_POWERED
 *				||	/\
 *				\/	||
 *	DEVICE_RESET				DEVICE_POWER_INTERRUPTION
 *				||	/\
 *				\/	||
 *				STATE_DEFAULT
 *				||	/\
 *				\/	||
 *	DEVICE_ADDRESS_ASSIGNED			DEVICE_RESET
 *				||	/\
 *				\/	||
 *				STATE_ADDRESSED
 *				||	/\
 *				\/	||
 *	DEVICE_CONFIGURED			DEVICE_DE_CONFIGURED
 *				||	/\
 *				\/	||
 *				STATE_CONFIGURED
 *
 * udc_state_transition_up transitions up (in the direction from STATE_ATTACHED
 * to STATE_CONFIGURED) from the specified initial state to the specified final
 * state, passing through each intermediate state on the way.  If the initial
 * state is at or above (i.e. nearer to STATE_CONFIGURED) the final state, then
 * no state transitions will take place.
 *
 * udc_state_transition_down transitions down (in the direction from
 * STATE_CONFIGURED to STATE_ATTACHED) from the specified initial state to the
 * specified final state, passing through each intermediate state on the way.
 * If the initial state is at or below (i.e. nearer to STATE_ATTACHED) the final
 * state, then no state transitions will take place.
 *
 */

static void mpc8xx_udc_state_transition_up (usb_device_state_t initial,
					    usb_device_state_t final)
{
	if (initial < final) {
		switch (initial) {
		case STATE_ATTACHED:
			usbd_device_event_irq (udc_device,
					       DEVICE_HUB_CONFIGURED, 0);
			if (final == STATE_POWERED)
				break;
		case STATE_POWERED:
			usbd_device_event_irq (udc_device, DEVICE_RESET, 0);
			if (final == STATE_DEFAULT)
				break;
		case STATE_DEFAULT:
			usbd_device_event_irq (udc_device,
					       DEVICE_ADDRESS_ASSIGNED, 0);
			if (final == STATE_ADDRESSED)
				break;
		case STATE_ADDRESSED:
			usbd_device_event_irq (udc_device, DEVICE_CONFIGURED,
					       0);
		case STATE_CONFIGURED:
			break;
		default:
			break;
		}
	}
}

static void mpc8xx_udc_state_transition_down (usb_device_state_t initial,
					      usb_device_state_t final)
{
	if (initial > final) {
		switch (initial) {
		case STATE_CONFIGURED:
			usbd_device_event_irq (udc_device,
					       DEVICE_DE_CONFIGURED, 0);
			if (final == STATE_ADDRESSED)
				break;
		case STATE_ADDRESSED:
			usbd_device_event_irq (udc_device, DEVICE_RESET, 0);
			if (final == STATE_DEFAULT)
				break;
		case STATE_DEFAULT:
			usbd_device_event_irq (udc_device,
					       DEVICE_POWER_INTERRUPTION, 0);
			if (final == STATE_POWERED)
				break;
		case STATE_POWERED:
			usbd_device_event_irq (udc_device, DEVICE_HUB_RESET,
					       0);
		case STATE_ATTACHED:
			break;
		default:
			break;
		}
	}
}

/* mpc8xx_udc_stall
 *
 * Force returning of STALL tokens on the given endpoint. Protocol or function
 * STALL conditions are permissable here
 */
static void mpc8xx_udc_stall (unsigned int ep)
{
	usbp->usep[ep] |= STALL_BITMASK;
}

/* mpc8xx_udc_set_nak
 *
 * Force returning of NAK responses for the given endpoint as a kind of very
 * simple flow control
 */
static void mpc8xx_udc_set_nak (unsigned int ep)
{
	usbp->usep[ep] |= NAK_BITMASK;
	__asm__ ("eieio");
}

/* mpc8xx_udc_handle_txerr
 *
 * Handle errors relevant to TX. Return a status code to allow calling
 * indicative of what if anything happened
 */
static short mpc8xx_udc_handle_txerr ()
{
	short ep = 0, ret = 0;

	for (; ep < TX_RING_SIZE; ep++) {
		if (usbp->usber & (0x10 << ep)) {

			/* Timeout or underrun */
			if (tx_cbd[ep]->cbd_sc & 0x06) {
				ret = 1;
				mpc8xx_udc_flush_tx_fifo (ep);

			} else {
				if (usbp->usep[ep] & STALL_BITMASK) {
					if (!ep) {
						usbp->usep[ep] &= ~STALL_BITMASK;
					}
				}	/* else NAK */
			}
			usbp->usber |= (0x10 << ep);
		}
	}
	return ret;
}

/* mpc8xx_udc_advance_rx
 *
 * Advance cbd rx
 */
static void mpc8xx_udc_advance_rx (volatile cbd_t ** rx_cbdp, int epid)
{
	if ((*rx_cbdp)->cbd_sc & RX_BD_W) {
		*rx_cbdp = (volatile cbd_t *) (endpoints[epid]->rbase + CFG_IMMR);

	} else {
		(*rx_cbdp)++;
	}
}


/* mpc8xx_udc_flush_tx_fifo
 *
 * Flush a given TX fifo. Assumes one tx cbd per endpoint
 */
static void mpc8xx_udc_flush_tx_fifo (int epid)
{
	volatile cbd_t *tx_cbdp = 0;

	if (epid > MAX_ENDPOINTS) {
		return;
	}

	/* TX stop */
	immr->im_cpm.cp_cpcr = ((epid << 2) | 0x1D01);
	__asm__ ("eieio");
	while (immr->im_cpm.cp_cpcr & 0x01);

	usbp->uscom = 0x40 | 0;

	/* reset ring */
	tx_cbdp = (cbd_t *) (endpoints[epid]->tbptr + CFG_IMMR);
	tx_cbdp->cbd_sc = (TX_BD_I | TX_BD_W);


	endpoints[epid]->tptr = endpoints[epid]->tbase;
	endpoints[epid]->tstate = 0x00;
	endpoints[epid]->tbcnt = 0x00;

	/* TX start */
	immr->im_cpm.cp_cpcr = ((epid << 2) | 0x2D01);
	__asm__ ("eieio");
	while (immr->im_cpm.cp_cpcr & 0x01);

	return;
}

/* mpc8xx_udc_flush_rx_fifo
 *
 * For the sake of completeness of the namespace, it seems like
 * a good-design-decision (tm) to include mpc8xx_udc_flush_rx_fifo();
 * If RX_BD_E is true => a driver bug either here or in an upper layer
 * not polling frequently enough. If RX_BD_E is true we have told the host
 * we have accepted data but, the CPM found it had no-where to put that data
 * which needless to say would be a bad thing.
 */
static void mpc8xx_udc_flush_rx_fifo ()
{
	int i = 0;

	for (i = 0; i < RX_RING_SIZE; i++) {
		if (!(rx_cbd[i]->cbd_sc & RX_BD_E)) {
			ERR ("buf %p used rx data len = 0x%x sc=0x%x!\n",
			     rx_cbd[i], rx_cbd[i]->cbd_datlen,
			     rx_cbd[i]->cbd_sc);

		}
	}
	ERR ("BUG : Input over-run\n");
}

/* mpc8xx_udc_clear_rxbd
 *
 * Release control of RX CBD to CP.
 */
static void mpc8xx_udc_clear_rxbd (volatile cbd_t * rx_cbdp)
{
	rx_cbdp->cbd_datlen = 0x0000;
	rx_cbdp->cbd_sc = ((rx_cbdp->cbd_sc & RX_BD_W) | (RX_BD_E | RX_BD_I));
	__asm__ ("eieio");
}

/* mpc8xx_udc_tx_irq
 *
 * Parse for tx timeout, control RX or USB reset/busy conditions
 * Return -1 on timeout, -2 on fatal error, else return zero
 */
static int mpc8xx_udc_tx_irq (int ep)
{
	int i = 0;

	if (usbp->usber & (USB_TX_ERRMASK)) {
		if (mpc8xx_udc_handle_txerr ()) {
			/* Timeout, controlling function must retry send */
			return -1;
		}
	}

	if (usbp->usber & (USB_E_RESET | USB_E_BSY)) {
		/* Fatal, abandon TX transaction */
		return -2;
	}

	if (usbp->usber & USB_E_RXB) {
		for (i = 0; i < RX_RING_SIZE; i++) {
			if (!(rx_cbd[i]->cbd_sc & RX_BD_E)) {
				if ((rx_cbd[i] == ep_ref[0].prx) || ep) {
					return -2;
				}
			}
		}
	}

	return 0;
}

/* mpc8xx_udc_ep_tx
 *
 * Transmit in a re-entrant fashion outbound USB packets.
 * Implement retry/timeout mechanism described in USB specification
 * Toggle DATA0/DATA1 pids as necessary
 * Introduces non-standard tx_retry. The USB standard has no scope for slave
 * devices to give up TX, however tx_retry stops us getting stuck in an endless
 * TX loop.
 */
static int mpc8xx_udc_ep_tx (struct usb_endpoint_instance *epi)
{
	struct urb *urb = epi->tx_urb;
	volatile cbd_t *tx_cbdp = 0;
	unsigned int ep = 0, pkt_len = 0, x = 0, tx_retry = 0;
	int ret = 0;

	if (!epi || (epi->endpoint_address & 0x03) >= MAX_ENDPOINTS || !urb) {
		return -1;
	}

	ep = epi->endpoint_address & 0x03;
	tx_cbdp = (cbd_t *) (endpoints[ep]->tbptr + CFG_IMMR);

	if (tx_cbdp->cbd_sc & TX_BD_R || usbp->usber & USB_E_TXB) {
		mpc8xx_udc_flush_tx_fifo (ep);
		usbp->usber |= USB_E_TXB;
	};

	while (tx_retry++ < 100) {
		ret = mpc8xx_udc_tx_irq (ep);
		if (ret == -1) {
			/* ignore timeout here */
		} else if (ret == -2) {
			/* Abandon TX */
			mpc8xx_udc_flush_tx_fifo (ep);
			return -1;
		}

		tx_cbdp = (cbd_t *) (endpoints[ep]->tbptr + CFG_IMMR);
		while (tx_cbdp->cbd_sc & TX_BD_R) {
		};
		tx_cbdp->cbd_sc = (tx_cbdp->cbd_sc & TX_BD_W);

		pkt_len = urb->actual_length - epi->sent;

		if (pkt_len > epi->tx_packetSize || pkt_len > EP_MAX_PKT) {
			pkt_len = MIN (epi->tx_packetSize, EP_MAX_PKT);
		}

		for (x = 0; x < pkt_len; x++) {
			*((unsigned char *) (tx_cbdp->cbd_bufaddr + x)) =
				urb->buffer[epi->sent + x];
		}
		tx_cbdp->cbd_datlen = pkt_len;
		tx_cbdp->cbd_sc |= (CBD_TX_BITMASK | ep_ref[ep].pid);
		__asm__ ("eieio");

#ifdef __SIMULATE_ERROR__
		if (++err_poison_test == 2) {
			err_poison_test = 0;
			tx_cbdp->cbd_sc &= ~TX_BD_TC;
		}
#endif

		usbp->uscom = (USCOM_STR | ep);

		while (!(usbp->usber & USB_E_TXB)) {
			ret = mpc8xx_udc_tx_irq (ep);
			if (ret == -1) {
				/* TX timeout */