at91_udc.c

usb driver for 2.6.17

			| 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(AT91_UDP_RST_EP, ep->int_mask);
		at91_udp_write(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 */
	status = udc->driver->setup(&udc->gadget, &pkt.r);
	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(AT91_UDP_FADDR, AT91_UDP_FEN | udc->addr);
				tmp = at91_udp_read(AT91_UDP_GLB_STAT);
				tmp &= ~AT91_UDP_FADDEN;
				if (udc->addr)
					tmp |= AT91_UDP_FADDEN;
				at91_udp_write(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 pt_regs *r)
{
	struct at91_udc		*udc = _udc;
	u32			rescans = 5;

	while (rescans--) {
		u32	status = at91_udp_read(AT91_UDP_ISR);

		status &= at91_udp_read(AT91_UDP_IMR);
		if (!status)
			break;

		/* USB reset irq:  not maskable */
		if (status & AT91_UDP_ENDBUSRES) {
			at91_udp_write(AT91_UDP_IDR, ~MINIMUS_INTERRUPTUS);
			at91_udp_write(AT91_UDP_IER, MINIMUS_INTERRUPTUS);
			/* Atmel code clears this irq twice */
			at91_udp_write(AT91_UDP_ICR, AT91_UDP_ENDBUSRES);
			at91_udp_write(AT91_UDP_ICR, AT91_UDP_ENDBUSRES);
			VDBG("end bus reset\n");
			udc->addr = 0;
			stop_activity(udc);

			/* enable ep0 */
			at91_udp_write(AT91_UDP_CSR(0), AT91_UDP_EPEDS | AT91_UDP_EPTYPE_CTRL);
			udc->gadget.speed = USB_SPEED_FULL;
			udc->suspended = 0;
			at91_udp_write(AT91_UDP_IER, AT91_UDP_EP(0));

			/*
			 * NOTE:  this driver keeps clocks off unless the
			 * USB host is present.  That saves power, and also
			 * eliminates IRQs (reset, resume, suspend) that can
			 * otherwise flood from the controller.  If your
			 * board doesn't support VBUS detection, suspend and
			 * resume irq logic may need more attention...
			 */

		/* host initiated suspend (3+ms bus idle) */
		} else if (status & AT91_UDP_RXSUSP) {
			at91_udp_write(AT91_UDP_IDR, AT91_UDP_RXSUSP);
			at91_udp_write(AT91_UDP_IER, AT91_UDP_RXRSM);
			at91_udp_write(AT91_UDP_ICR, AT91_UDP_RXSUSP);
			// VDBG("bus suspend\n");
			if (udc->suspended)
				continue;
			udc->suspended = 1;

			/*
			 * NOTE:  when suspending a VBUS-powered device, the
			 * gadget driver should switch into slow clock mode
			 * and then into standby to avoid drawing more than
			 * 500uA power (2500uA for some high-power configs).
			 */
			if (udc->driver && udc->driver->suspend)
				udc->driver->suspend(&udc->gadget);

		/* host initiated resume */
		} else if (status & AT91_UDP_RXRSM) {
			at91_udp_write(AT91_UDP_IDR, AT91_UDP_RXRSM);
			at91_udp_write(AT91_UDP_IER, AT91_UDP_RXSUSP);
			at91_udp_write(AT91_UDP_ICR, AT91_UDP_RXRSM);
			// VDBG("bus resume\n");
			if (!udc->suspended)
				continue;
			udc->suspended = 0;

			/*
			 * NOTE:  for a VBUS-powered device, the gadget driver
			 * would normally want to switch out of slow clock
			 * mode into normal mode.
			 */
			if (udc->driver && udc->driver->resume)
				udc->driver->resume(&udc->gadget);

		/* endpoint IRQs are cleared by handling them */
		} else {
			int		i;
			unsigned	mask = 1;
			struct at91_ep	*ep = &udc->ep[1];

			if (status & mask)
				handle_ep0(udc);
			for (i = 1; i < NUM_ENDPOINTS; i++) {
				mask <<= 1;
				if (status & mask)
					handle_ep(ep);
				ep++;
			}
		}
	}

	return IRQ_HANDLED;
}

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

static struct at91_udc controller = {
	.gadget = {
		.ops = &at91_udc_ops,
		.ep0 = &controller.ep[0].ep,
		.name = driver_name,
		.dev = {
			.bus_id = "gadget"
		}
	},
	.ep[0] = {
		.ep = {
			.name	= ep0name,
			.ops	= &at91_ep_ops,
		},
		.udc		= &controller,
		.maxpacket	= 8,
		.creg		= (void __iomem *)(AT91_VA_BASE_UDP + AT91_UDP_CSR(0)),
		.int_mask	= 1 << 0,
	},
	.ep[1] = {
		.ep = {
			.name	= "ep1",
			.ops	= &at91_ep_ops,
		},
		.udc		= &controller,
		.is_pingpong	= 1,
		.maxpacket	= 64,
		.creg		= (void __iomem *)(AT91_VA_BASE_UDP + AT91_UDP_CSR(1)),
		.int_mask	= 1 << 1,
	},
	.ep[2] = {
		.ep = {
			.name	= "ep2",
			.ops	= &at91_ep_ops,
		},
		.udc		= &controller,
		.is_pingpong	= 1,
		.maxpacket	= 64,
		.creg		= (void __iomem *)(AT91_VA_BASE_UDP + AT91_UDP_CSR(2)),
		.int_mask	= 1 << 2,
	},
	.ep[3] = {
		.ep = {
			/* could actually do bulk too */
			.name	= "ep3-int",
			.ops	= &at91_ep_ops,
		},
		.udc		= &controller,
		.maxpacket	= 8,
		.creg		= (void __iomem *)(AT91_VA_BASE_UDP + AT91_UDP_CSR(3)),
		.int_mask	= 1 << 3,
	},
	.ep[4] = {
		.ep = {
			.name	= "ep4",
			.ops	= &at91_ep_ops,
		},
		.udc		= &controller,
		.is_pingpong	= 1,
		.maxpacket	= 256,
		.creg		= (void __iomem *)(AT91_VA_BASE_UDP + AT91_UDP_CSR(4)),
		.int_mask	= 1 << 4,
	},
	.ep[5] = {
		.ep = {
			.name	= "ep5",
			.ops	= &at91_ep_ops,
		},
		.udc		= &controller,
		.is_pingpong	= 1,
		.maxpacket	= 256,
		.creg		= (void __iomem *)(AT91_VA_BASE_UDP + AT91_UDP_CSR(5)),
		.int_mask	= 1 << 5,
	},
	/* ep6 and ep7 are also reserved */
};

static irqreturn_t at91_vbus_irq(int irq, void *_udc, struct pt_regs *r)
{
	struct at91_udc	*udc = _udc;
	unsigned	value;

	/* vbus needs at least brief debouncing */
	udelay(10);
	value = at91_get_gpio_value(udc->board.vbus_pin);
	if (value != udc->vbus)
		at91_vbus_session(&udc->gadget, value);

	return IRQ_HANDLED;
}

int usb_gadget_register_driver (struct usb_gadget_driver *driver)
{
	struct at91_udc	*udc = &controller;
	int		retval;

	if (!driver
			|| driver->speed != USB_SPEED_FULL
			|| !driver->bind
			|| !driver->unbind
			|| !driver->setup) {
		DBG("bad parameter.\n");
		return -EINVAL;
	}

	if (udc->driver) {
		DBG("UDC already has a gadget driver\n");
		return -EBUSY;
	}

	udc->driver = driver;
	udc->gadget.dev.driver = &driver->driver;
	udc->gadget.dev.driver_data = &driver->driver;
	udc->enabled = 1;
	udc->selfpowered = 1;

	retval = driver->bind(&udc->gadget);
	if (retval) {
		DBG("driver->bind() returned %d\n", retval);
		udc->driver = NULL;
		return retval;
	}

	local_irq_disable();
	pullup(udc, 1);
	local_irq_enable();

	DBG("bound to %s\n", driver->driver.name);
	return 0;
}
EXPORT_SYMBOL (usb_gadget_register_driver);

int usb_gadget_unregister_driver (struct usb_gadget_driver *driver)
{
	struct at91_udc *udc = &controller;

	if (!driver || driver != udc->driver)
		return -EINVAL;

	local_irq_disable();
	udc->enabled = 0;
	pullup(udc, 0);
	local_irq_enable();

	driver->unbind(&udc->gadget);
	udc->driver = NULL;

	DBG("unbound from %s\n", driver->driver.name);
	return 0;
}
EXPORT_SYMBOL (usb_gadget_unregister_driver);

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

static void at91udc_shutdown(struct platform_device *dev)
{
	/* force disconnect on reboot */
	pullup(platform_get_drvdata(dev), 0);
}

static int __devinit at91udc_probe(struct platform_device *pdev)
{
	struct device	*dev = &pdev->dev;
	struct at91_udc	*udc;
	int		retval;

	if (!dev->platform_data) {
		/* small (so we copy it) but critical! */
		DBG("missing platform_data\n");
		return -ENODEV;
	}

	if (!request_mem_region(AT91_BASE_UDP, SZ_16K, driver_name)) {
		DBG("someone's using UDC memory\n");
		return -EBUSY;
	}

	/* init software state */
	udc = &controller;
	udc->gadget.dev.parent = dev;
	udc->board = *(struct at91_udc_data *) dev->platform_data;
	udc->pdev = pdev;
	udc_reinit(udc);
	udc->enabled = 0;

	/* get interface and function clocks */
	udc->iclk = clk_get(dev, "udc_clk");
	udc->fclk = clk_get(dev, "udpck");
	if (IS_ERR(udc->iclk) || IS_ERR(udc->fclk)) {
		DBG("clocks missing\n");
		return -ENODEV;
	}

	retval = device_register(&udc->gadget.dev);
	if (retval < 0)
		goto fail0;

	/* disable everything until there's a gadget driver and vbus */
	pullup(udc, 0);

	/* request UDC and maybe VBUS irqs */
	if (request_irq(AT91_ID_UDP, at91_udc_irq, SA_INTERRUPT, driver_name, udc)) {
		DBG("request irq %d failed\n", AT91_ID_UDP);
		retval = -EBUSY;
		goto fail1;
	}
	if (udc->board.vbus_pin > 0) {
		if (request_irq(udc->board.vbus_pin, at91_vbus_irq, SA_INTERRUPT, driver_name, udc)) {
			DBG("request vbus irq %d failed\n", udc->board.vbus_pin);
			free_irq(AT91_ID_UDP, udc);
			retval = -EBUSY;
			goto fail1;
		}
	} else {
		DBG("no VBUS detection, assuming always-on\n");
		udc->vbus = 1;
	}
	dev_set_drvdata(dev, udc);
	create_debug_file(udc);

	INFO("%s version %s\n", driver_name, DRIVER_VERSION);
	return 0;

fail1:
	device_unregister(&udc->gadget.dev);
fail0:
	release_mem_region(AT91_VA_BASE_UDP, SZ_16K);
	DBG("%s probe failed, %d\n", driver_name, retval);
	return retval;
}

static int __devexit at91udc_remove(struct platform_device *dev)
{
	struct at91_udc *udc = platform_get_drvdata(dev);

	DBG("remove\n");

	pullup(udc, 0);

	if (udc->driver != 0)
		usb_gadget_unregister_driver(udc->driver);

	remove_debug_file(udc);
	if (udc->board.vbus_pin > 0)
		free_irq(udc->board.vbus_pin, udc);
	free_irq(AT91_ID_UDP, udc);
	device_unregister(&udc->gadget.dev);
	release_mem_region(AT91_BASE_UDP, SZ_16K);

	clk_put(udc->iclk);
	clk_put(udc->fclk);

	return 0;
}

#ifdef CONFIG_PM
static int at91udc_suspend(struct platform_device *dev, pm_message_t mesg)
{
	struct at91_udc *udc = platform_get_drvdata(dev);

	/*
	 * The "safe" suspend transitions are opportunistic ... e.g. when
	 * the USB link is suspended (48MHz clock autogated off), or when
	 * it's disconnected (programmatically gated off, elsewhere).
	 * Then we can suspend, and the chip can enter slow clock mode.
	 *
	 * The problem case is some component (user mode?) suspending this
	 * device while it's active, with the 48 MHz clock in use.  There
	 * are two basic approaches:  (a) veto suspend levels involving slow
	 * clock mode, (b) disconnect, so 48 MHz will no longer be in use
	 * and we can enter slow clock mode.  This uses (b) for now, since
	 * it's simplest until AT91 PM exists and supports the other option.
	 */
	if (udc->vbus && !udc->suspended)
		pullup(udc, 0);
	return 0;
}

static int at91udc_resume(struct platform_device *dev)
{
	struct at91_udc *udc = platform_get_drvdata(dev);

	/* maybe reconnect to host; if so, clocks on */
	pullup(udc, 1);
	return 0;
}
#else
#define	at91udc_suspend	NULL
#define	at91udc_resume	NULL
#endif

static struct platform_driver at91_udc = {
	.probe		= at91udc_probe,
	.remove		= __devexit_p(at91udc_remove),
	.shutdown	= at91udc_shutdown,
	.suspend	= at91udc_suspend,
	.resume 	= at91udc_resume,
	.driver		= {
		.name	= (char *) driver_name,
		.owner	= THIS_MODULE,
	},
};

static int __devinit udc_init_module(void)
{
	return platform_driver_register(&at91_udc);
}
module_init(udc_init_module);

static void __devexit udc_exit_module(void)
{
	platform_driver_unregister(&at91_udc);
}
module_exit(udc_exit_module);

MODULE_DESCRIPTION("AT91RM9200 udc driver");
MODULE_AUTHOR("Thomas Rathbone, David Brownell");
MODULE_LICENSE("GPL");