at91_udc.c

linux下面gadget设备驱动

			break;

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

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

			/*
			 * NOTE:  this driver keeps clocks off unless the
			 * USB host is present.  That saves power, but for
			 * boards that don't support VBUS detection, both
			 * clocks need to be active most of the time.
			 */

		/* host initiated suspend (3+ms bus idle) */
		} else if (status & AT91_UDP_RXSUSP) {
			at91_udp_write(udc, AT91_UDP_IDR, AT91_UDP_RXSUSP);
			at91_udp_write(udc, AT91_UDP_IER, AT91_UDP_RXRSM);
			at91_udp_write(udc, 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(udc, AT91_UDP_IDR, AT91_UDP_RXRSM);
			at91_udp_write(udc, AT91_UDP_IER, AT91_UDP_RXSUSP);
			at91_udp_write(udc, 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 void nop_release(struct device *dev)
{
	/* nothing to free */
}

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

static irqreturn_t at91_vbus_irq(int irq, void *_udc)
{
	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->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;
		udc->gadget.dev.driver = NULL;
		udc->gadget.dev.driver_data = NULL;
		udc->enabled = 0;
		udc->selfpowered = 0;
		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 || !driver->unbind)
		return -EINVAL;

	local_irq_disable();
	udc->enabled = 0;
	at91_udp_write(udc, AT91_UDP_IDR, ~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 __init at91udc_probe(struct platform_device *pdev)
{
	struct device	*dev = &pdev->dev;
	struct at91_udc	*udc;
	int		retval;
	struct resource	*res;

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

	if (pdev->num_resources != 2) {
		DBG("invalid num_resources");
		return -ENODEV;
	}
	if ((pdev->resource[0].flags != IORESOURCE_MEM)
			|| (pdev->resource[1].flags != IORESOURCE_IRQ)) {
		DBG("invalid resource type");
		return -ENODEV;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		return -ENXIO;

	if (!request_mem_region(res->start,
			res->end - res->start + 1,
			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->enabled = 0;

	udc->udp_baseaddr = ioremap(res->start, res->end - res->start + 1);
	if (!udc->udp_baseaddr) {
		release_mem_region(res->start, res->end - res->start + 1);
		return -ENOMEM;
	}

	udc_reinit(udc);

	/* 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");
		retval = -ENODEV;
		goto fail0;
	}

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

	/* don't do anything until we have both gadget driver and VBUS */
	clk_enable(udc->iclk);
	at91_udp_write(udc, AT91_UDP_TXVC, AT91_UDP_TXVC_TXVDIS);
	at91_udp_write(udc, AT91_UDP_IDR, 0xffffffff);
	/* Clear all pending interrupts - UDP may be used by bootloader. */
	at91_udp_write(udc, AT91_UDP_ICR, 0xffffffff);
	clk_disable(udc->iclk);

	/* request UDC and maybe VBUS irqs */
	udc->udp_irq = platform_get_irq(pdev, 0);
	if (request_irq(udc->udp_irq, at91_udc_irq,
			IRQF_DISABLED, driver_name, udc)) {
		DBG("request irq %d failed\n", udc->udp_irq);
		retval = -EBUSY;
		goto fail1;
	}
	if (udc->board.vbus_pin > 0) {
		/*
		 * Get the initial state of VBUS - we cannot expect
		 * a pending interrupt.
		 */
		udc->vbus = at91_get_gpio_value(udc->board.vbus_pin);
		if (request_irq(udc->board.vbus_pin, at91_vbus_irq,
				IRQF_DISABLED, driver_name, udc)) {
			DBG("request vbus irq %d failed\n",
					udc->board.vbus_pin);
			free_irq(udc->udp_irq, udc);
			retval = -EBUSY;
			goto fail1;
		}
	} else {
		DBG("no VBUS detection, assuming always-on\n");
		udc->vbus = 1;
	}
	dev_set_drvdata(dev, udc);
	device_init_wakeup(dev, 1);
	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(res->start, res->end - res->start + 1);
	DBG("%s probe failed, %d\n", driver_name, retval);
	return retval;
}

static int __exit at91udc_remove(struct platform_device *pdev)
{
	struct at91_udc *udc = platform_get_drvdata(pdev);
	struct resource *res;

	DBG("remove\n");

	if (udc->driver)
		return -EBUSY;

	pullup(udc, 0);

	device_init_wakeup(&pdev->dev, 0);
	remove_debug_file(udc);
	if (udc->board.vbus_pin > 0)
		free_irq(udc->board.vbus_pin, udc);
	free_irq(udc->udp_irq, udc);
	device_unregister(&udc->gadget.dev);

	iounmap(udc->udp_baseaddr);
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	release_mem_region(res->start, res->end - res->start + 1);

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

	return 0;
}

#ifdef CONFIG_PM
static int at91udc_suspend(struct platform_device *pdev, pm_message_t mesg)
{
	struct at91_udc *udc = platform_get_drvdata(pdev);
	int		wake = udc->driver && device_may_wakeup(&pdev->dev);

	/* Unless we can act normally to the host (letting it wake us up
	 * whenever it has work for us) force disconnect.  Wakeup requires
	 * PLLB for USB events (signaling for reset, wakeup, or incoming
	 * tokens) and VBUS irqs (on systems which support them).
	 */
	if ((!udc->suspended && udc->addr)
			|| !wake
			|| at91_suspend_entering_slow_clock()) {
		pullup(udc, 0);
		wake = 0;
	} else
		enable_irq_wake(udc->udp_irq);

	udc->active_suspend = wake;
	if (udc->board.vbus_pin > 0 && wake)
		enable_irq_wake(udc->board.vbus_pin);
	return 0;
}

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

	if (udc->board.vbus_pin > 0 && udc->active_suspend)
		disable_irq_wake(udc->board.vbus_pin);

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

static struct platform_driver at91_udc_driver = {
	.remove		= __exit_p(at91udc_remove),
	.shutdown	= at91udc_shutdown,
	.suspend	= at91udc_suspend,
	.resume		= at91udc_resume,
	.driver		= {
		.name	= (char *) driver_name,
		.owner	= THIS_MODULE,
	},
};

static int __init udc_init_module(void)
{
	return platform_driver_probe(&at91_udc_driver, at91udc_probe);
}
module_init(udc_init_module);

static void __exit udc_exit_module(void)
{
	platform_driver_unregister(&at91_udc_driver);
}
module_exit(udc_exit_module);

MODULE_DESCRIPTION("AT91 udc driver");
MODULE_AUTHOR("Thomas Rathbone, David Brownell");
MODULE_LICENSE("GPL");