at91_udc.c

linux下面gadget设备驱动

		}
		clk_off(udc);
	}
}

/* vbus is here!  turn everything on that's ready */
static int at91_vbus_session(struct usb_gadget *gadget, int is_active)
{
	struct at91_udc	*udc = to_udc(gadget);
	unsigned long	flags;

	// VDBG("vbus %s\n", is_active ? "on" : "off");
	local_irq_save(flags);
	udc->vbus = (is_active != 0);
	if (udc->driver)
		pullup(udc, is_active);
	else
		pullup(udc, 0);
	local_irq_restore(flags);
	return 0;
}

static int at91_pullup(struct usb_gadget *gadget, int is_on)
{
	struct at91_udc	*udc = to_udc(gadget);
	unsigned long	flags;

	local_irq_save(flags);
	udc->enabled = is_on = !!is_on;
	pullup(udc, is_on);
	local_irq_restore(flags);
	return 0;
}

static int at91_set_selfpowered(struct usb_gadget *gadget, int is_on)
{
	struct at91_udc	*udc = to_udc(gadget);
	unsigned long	flags;

	local_irq_save(flags);
	udc->selfpowered = (is_on != 0);
	local_irq_restore(flags);
	return 0;
}

static const struct usb_gadget_ops at91_udc_ops = {
	.get_frame		= at91_get_frame,
	.wakeup			= at91_wakeup,
	.set_selfpowered	= at91_set_selfpowered,
	.vbus_session		= at91_vbus_session,
	.pullup			= at91_pullup,

	/*
	 * VBUS-powered devices may also also want to support bigger
	 * power budgets after an appropriate SET_CONFIGURATION.
	 */
	// .vbus_power		= at91_vbus_power,
};

/*-------------------------------------------------------------------------*/

static int handle_ep(struct at91_ep *ep)
{
	struct at91_request	*req;
	u32 __iomem		*creg = ep->creg;
	u32			csr = __raw_readl(creg);

	if (!list_empty(&ep->queue))
		req = list_entry(ep->queue.next,
			struct at91_request, queue);
	else
		req = NULL;

	if (ep->is_in) {
		if (csr & (AT91_UDP_STALLSENT | AT91_UDP_TXCOMP)) {
			csr |= CLR_FX;
			csr &= ~(SET_FX | AT91_UDP_STALLSENT | AT91_UDP_TXCOMP);
			__raw_writel(csr, creg);
		}
		if (req)
			return write_fifo(ep, req);

	} else {
		if (csr & AT91_UDP_STALLSENT) {
			/* STALLSENT bit == ISOERR */
			if (ep->is_iso && req)
				req->req.status = -EILSEQ;
			csr |= CLR_FX;
			csr &= ~(SET_FX | AT91_UDP_STALLSENT);
			__raw_writel(csr, creg);
			csr = __raw_readl(creg);
		}
		if (req && (csr & RX_DATA_READY))
			return read_fifo(ep, req);
	}
	return 0;
}

union setup {
	u8			raw[8];
	struct usb_ctrlrequest	r;
};

static void handle_setup(struct at91_udc *udc, struct at91_ep *ep, u32 csr)
{
	u32 __iomem	*creg = ep->creg;
	u8 __iomem	*dreg = ep->creg + (AT91_UDP_FDR(0) - AT91_UDP_CSR(0));
	unsigned	rxcount, i = 0;
	u32		tmp;
	union setup	pkt;
	int		status = 0;

	/* read and ack SETUP; hard-fail for bogus packets */
	rxcount = (csr & AT91_UDP_RXBYTECNT) >> 16;
	if (likely(rxcount == 8)) {
		while (rxcount--)
			pkt.raw[i++] = __raw_readb(dreg);
		if (pkt.r.bRequestType & USB_DIR_IN) {
			csr |= AT91_UDP_DIR;
			ep->is_in = 1;
		} else {
			csr &= ~AT91_UDP_DIR;
			ep->is_in = 0;
		}
	} else {
		// REVISIT this happens sometimes under load; why??
		ERR("SETUP len %d, csr %08x\n", rxcount, csr);
		status = -EINVAL;
	}
	csr |= CLR_FX;
	csr &= ~(SET_FX | AT91_UDP_RXSETUP);
	__raw_writel(csr, creg);
	udc->wait_for_addr_ack = 0;
	udc->wait_for_config_ack = 0;
	ep->stopped = 0;
	if (unlikely(status != 0))
		goto stall;

#define w_index		le16_to_cpu(pkt.r.wIndex)
#define w_value		le16_to_cpu(pkt.r.wValue)
#define w_length	le16_to_cpu(pkt.r.wLength)

	VDBG("SETUP %02x.%02x v%04x i%04x l%04x\n",
			pkt.r.bRequestType, pkt.r.bRequest,
			w_value, w_index, w_length);

	/*
	 * A few standard requests get handled here, ones that touch
	 * hardware ... notably for device and endpoint features.
	 */
	udc->req_pending = 1;
	csr = __raw_readl(creg);
	csr |= CLR_FX;
	csr &= ~SET_FX;
	switch ((pkt.r.bRequestType << 8) | pkt.r.bRequest) {

	case ((USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
			| USB_REQ_SET_ADDRESS:
		__raw_writel(csr | AT91_UDP_TXPKTRDY, creg);
		udc->addr = w_value;
		udc->wait_for_addr_ack = 1;
		udc->req_pending = 0;
		/* FADDR is set later, when we ack host STATUS */
		return;

	case ((USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
			| USB_REQ_SET_CONFIGURATION:
		tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT) & AT91_UDP_CONFG;
		if (pkt.r.wValue)
			udc->wait_for_config_ack = (tmp == 0);
		else
			udc->wait_for_config_ack = (tmp != 0);
		if (udc->wait_for_config_ack)
			VDBG("wait for config\n");
		/* CONFG is toggled later, if gadget driver succeeds */
		break;

	/*
	 * Hosts may set or clear remote wakeup status, and
	 * devices may report they're VBUS powered.
	 */
	case ((USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
			| USB_REQ_GET_STATUS:
		tmp = (udc->selfpowered << USB_DEVICE_SELF_POWERED);
		if (at91_udp_read(udc, AT91_UDP_GLB_STAT) & AT91_UDP_ESR)
			tmp |= (1 << USB_DEVICE_REMOTE_WAKEUP);
		PACKET("get device status\n");
		__raw_writeb(tmp, dreg);
		__raw_writeb(0, dreg);
		goto write_in;
		/* then STATUS starts later, automatically */
	case ((USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
			| USB_REQ_SET_FEATURE:
		if (w_value != USB_DEVICE_REMOTE_WAKEUP)
			goto stall;
		tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
		tmp |= AT91_UDP_ESR;
		at91_udp_write(udc, AT91_UDP_GLB_STAT, tmp);
		goto succeed;
	case ((USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
			| USB_REQ_CLEAR_FEATURE:
		if (w_value != USB_DEVICE_REMOTE_WAKEUP)
			goto stall;
		tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
		tmp &= ~AT91_UDP_ESR;
		at91_udp_write(udc, AT91_UDP_GLB_STAT, tmp);
		goto succeed;

	/*
	 * Interfaces have no feature settings; this is pretty useless.
	 * we won't even insist the interface exists...
	 */
	case ((USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_INTERFACE) << 8)
			| USB_REQ_GET_STATUS:
		PACKET("get interface status\n");
		__raw_writeb(0, dreg);
		__raw_writeb(0, dreg);
		goto write_in;
		/* then STATUS starts later, automatically */
	case ((USB_TYPE_STANDARD|USB_RECIP_INTERFACE) << 8)
			| USB_REQ_SET_FEATURE:
	case ((USB_TYPE_STANDARD|USB_RECIP_INTERFACE) << 8)
			| USB_REQ_CLEAR_FEATURE:
		goto stall;

	/*
	 * Hosts may clear bulk/intr endpoint halt after the gadget
	 * driver sets it (not widely used); or set it (for testing)
	 */
	case ((USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_ENDPOINT) << 8)
			| USB_REQ_GET_STATUS:
		tmp = w_index & USB_ENDPOINT_NUMBER_MASK;
		ep = &udc->ep[tmp];
		if (tmp > NUM_ENDPOINTS || (tmp && !ep->desc))
			goto stall;

		if (tmp) {
			if ((w_index & USB_DIR_IN)) {
				if (!ep->is_in)
					goto stall;
			} else if (ep->is_in)
				goto stall;
		}
		PACKET("get %s status\n", ep->ep.name);
		if (__raw_readl(ep->creg) & AT91_UDP_FORCESTALL)
			tmp = (1 << USB_ENDPOINT_HALT);
		else
			tmp = 0;
		__raw_writeb(tmp, dreg);
		__raw_writeb(0, dreg);
		goto write_in;
		/* then STATUS starts later, automatically */
	case ((USB_TYPE_STANDARD|USB_RECIP_ENDPOINT) << 8)
			| USB_REQ_SET_FEATURE:
		tmp = w_index & USB_ENDPOINT_NUMBER_MASK;
		ep = &udc->ep[tmp];
		if (w_value != USB_ENDPOINT_HALT || tmp > NUM_ENDPOINTS)
			goto stall;
		if (!ep->desc || ep->is_iso)
			goto stall;
		if ((w_index & USB_DIR_IN)) {
			if (!ep->is_in)
				goto stall;
		} else if (ep->is_in)
			goto stall;

		tmp = __raw_readl(ep->creg);
		tmp &= ~SET_FX;
		tmp |= CLR_FX | AT91_UDP_FORCESTALL;
		__raw_writel(tmp, ep->creg);
		goto succeed;
	case ((USB_TYPE_STANDARD|USB_RECIP_ENDPOINT) << 8)
			| USB_REQ_CLEAR_FEATURE:
		tmp = w_index & USB_ENDPOINT_NUMBER_MASK;
		ep = &udc->ep[tmp];
		if (w_value != USB_ENDPOINT_HALT || tmp > NUM_ENDPOINTS)
			goto stall;
		if (tmp == 0)
			goto succeed;
		if (!ep->desc || ep->is_iso)
			goto stall;
		if ((w_index & USB_DIR_IN)) {
			if (!ep->is_in)
				goto stall;
		} else if (ep->is_in)
			goto stall;

		at91_udp_write(udc, AT91_UDP_RST_EP, ep->int_mask);
		at91_udp_write(udc, AT91_UDP_RST_EP, 0);
		tmp = __raw_readl(ep->creg);
		tmp |= CLR_FX;
		tmp &= ~(SET_FX | AT91_UDP_FORCESTALL);
		__raw_writel(tmp, ep->creg);
		if (!list_empty(&ep->queue))
			handle_ep(ep);
		goto succeed;
	}

#undef w_value
#undef w_index
#undef w_length

	/* pass request up to the gadget driver */
	if (udc->driver)
		status = udc->driver->setup(&udc->gadget, &pkt.r);
	else
		status = -ENODEV;
	if (status < 0) {
stall:
		VDBG("req %02x.%02x protocol STALL; stat %d\n",
				pkt.r.bRequestType, pkt.r.bRequest, status);
		csr |= AT91_UDP_FORCESTALL;
		__raw_writel(csr, creg);
		udc->req_pending = 0;
	}
	return;

succeed:
	/* immediate successful (IN) STATUS after zero length DATA */
	PACKET("ep0 in/status\n");
write_in:
	csr |= AT91_UDP_TXPKTRDY;
	__raw_writel(csr, creg);
	udc->req_pending = 0;
	return;
}

static void handle_ep0(struct at91_udc *udc)
{
	struct at91_ep		*ep0 = &udc->ep[0];
	u32 __iomem		*creg = ep0->creg;
	u32			csr = __raw_readl(creg);
	struct at91_request	*req;

	if (unlikely(csr & AT91_UDP_STALLSENT)) {
		nuke(ep0, -EPROTO);
		udc->req_pending = 0;
		csr |= CLR_FX;
		csr &= ~(SET_FX | AT91_UDP_STALLSENT | AT91_UDP_FORCESTALL);
		__raw_writel(csr, creg);
		VDBG("ep0 stalled\n");
		csr = __raw_readl(creg);
	}
	if (csr & AT91_UDP_RXSETUP) {
		nuke(ep0, 0);
		udc->req_pending = 0;
		handle_setup(udc, ep0, csr);
		return;
	}

	if (list_empty(&ep0->queue))
		req = NULL;
	else
		req = list_entry(ep0->queue.next, struct at91_request, queue);

	/* host ACKed an IN packet that we sent */
	if (csr & AT91_UDP_TXCOMP) {
		csr |= CLR_FX;
		csr &= ~(SET_FX | AT91_UDP_TXCOMP);

		/* write more IN DATA? */
		if (req && ep0->is_in) {
			if (handle_ep(ep0))
				udc->req_pending = 0;

		/*
		 * Ack after:
		 *  - last IN DATA packet (including GET_STATUS)
		 *  - IN/STATUS for OUT DATA
		 *  - IN/STATUS for any zero-length DATA stage
		 * except for the IN DATA case, the host should send
		 * an OUT status later, which we'll ack.
		 */
		} else {
			udc->req_pending = 0;
			__raw_writel(csr, creg);

			/*
			 * SET_ADDRESS takes effect only after the STATUS
			 * (to the original address) gets acked.
			 */
			if (udc->wait_for_addr_ack) {
				u32	tmp;

				at91_udp_write(udc, AT91_UDP_FADDR,
						AT91_UDP_FEN | udc->addr);
				tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
				tmp &= ~AT91_UDP_FADDEN;
				if (udc->addr)
					tmp |= AT91_UDP_FADDEN;
				at91_udp_write(udc, AT91_UDP_GLB_STAT, tmp);

				udc->wait_for_addr_ack = 0;
				VDBG("address %d\n", udc->addr);
			}
		}
	}

	/* OUT packet arrived ... */
	else if (csr & AT91_UDP_RX_DATA_BK0) {
		csr |= CLR_FX;
		csr &= ~(SET_FX | AT91_UDP_RX_DATA_BK0);

		/* OUT DATA stage */
		if (!ep0->is_in) {
			if (req) {
				if (handle_ep(ep0)) {
					/* send IN/STATUS */
					PACKET("ep0 in/status\n");
					csr = __raw_readl(creg);
					csr &= ~SET_FX;
					csr |= CLR_FX | AT91_UDP_TXPKTRDY;
					__raw_writel(csr, creg);
					udc->req_pending = 0;
				}
			} else if (udc->req_pending) {
				/*
				 * AT91 hardware has a hard time with this
				 * "deferred response" mode for control-OUT
				 * transfers.  (For control-IN it's fine.)
				 *
				 * The normal solution leaves OUT data in the
				 * fifo until the gadget driver is ready.
				 * We couldn't do that here without disabling
				 * the IRQ that tells about SETUP packets,
				 * e.g. when the host gets impatient...
				 *
				 * Working around it by copying into a buffer
				 * would almost be a non-deferred response,
				 * except that it wouldn't permit reliable
				 * stalling of the request.  Instead, demand
				 * that gadget drivers not use this mode.
				 */
				DBG("no control-OUT deferred responses!\n");
				__raw_writel(csr | AT91_UDP_FORCESTALL, creg);
				udc->req_pending = 0;
			}

		/* STATUS stage for control-IN; ack.  */
		} else {
			PACKET("ep0 out/status ACK\n");
			__raw_writel(csr, creg);

			/* "early" status stage */
			if (req)
				done(ep0, req, 0);
		}
	}
}

static irqreturn_t at91_udc_irq (int irq, void *_udc)
{
	struct at91_udc		*udc = _udc;
	u32			rescans = 5;

	while (rescans--) {
		u32 status;

		status = at91_udp_read(udc, AT91_UDP_ISR)
			& at91_udp_read(udc, AT91_UDP_IMR);
		if (!status)