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Commit b633d28e authored by Darius Augulis's avatar Darius Augulis Committed by Greg Kroah-Hartman
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USB: imx_udc: Fix IMX UDC gadget general irq handling 



Workaround of hw bug in IMX UDC.
This bug causes wrong handling of CFG_CHG interrupt.
Workaround is documented inline source code.

Signed-off-by: default avatarDarius Augulis <augulis.darius@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent d24921a3

drivers/usb/gadget/imx_udc.c

+93 −65
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <linux/dma-mapping.h>

#include <linux/clk.h>

#include <linux/delay.h>

#include <linux/timer.h>



#include <linux/usb/ch9.h>

#include <linux/usb/gadget.h>
@@ -1013,50 +1014,18 @@ static void udc_stop_activity(struct imx_udc_struct *imx_usb, 
 *******************************************************************************

 */



static irqreturn_t imx_udc_irq(int irq, void *dev)

/*

 * Called when timer expires.

 * Timer is started when CFG_CHG is received.

 */

static void handle_config(unsigned long data)

{

	struct imx_udc_struct *imx_usb = dev;

	struct imx_udc_struct *imx_usb = (void *)data;

	struct usb_ctrlrequest u;

	int temp, cfg, intf, alt;

	int intr = __raw_readl(imx_usb->base + USB_INTR);



	if (intr & (INTR_WAKEUP | INTR_SUSPEND | INTR_RESUME | INTR_RESET_START

			| INTR_RESET_STOP | INTR_CFG_CHG)) {

				dump_intr(__func__, intr, imx_usb->dev);

				dump_usb_stat(__func__, imx_usb);

	}



	if (!imx_usb->driver)

		goto end_irq;



	if (intr & INTR_WAKEUP) {

		if (imx_usb->gadget.speed == USB_SPEED_UNKNOWN

			&& imx_usb->driver && imx_usb->driver->resume)

				imx_usb->driver->resume(&imx_usb->gadget);

		imx_usb->set_config = 0;

		imx_usb->gadget.speed = USB_SPEED_FULL;

	}

	local_irq_disable();



	if (intr & INTR_SUSPEND) {

		if (imx_usb->gadget.speed != USB_SPEED_UNKNOWN

			&& imx_usb->driver && imx_usb->driver->suspend)

				imx_usb->driver->suspend(&imx_usb->gadget);

		imx_usb->set_config = 0;

		imx_usb->gadget.speed = USB_SPEED_UNKNOWN;

	}



	if (intr & INTR_RESET_START) {

		__raw_writel(intr, imx_usb->base + USB_INTR);

		udc_stop_activity(imx_usb, imx_usb->driver);

		imx_usb->set_config = 0;

		imx_usb->gadget.speed = USB_SPEED_UNKNOWN;

	}



	if (intr & INTR_RESET_STOP)

		imx_usb->gadget.speed = USB_SPEED_FULL;



	if (intr & INTR_CFG_CHG) {

		__raw_writel(INTR_CFG_CHG, imx_usb->base + USB_INTR);

	temp = __raw_readl(imx_usb->base + USB_STAT);

	cfg  = (temp & STAT_CFG) >> 5;

	intf = (temp & STAT_INTF) >> 3;
@@ -1068,15 +1037,9 @@ static irqreturn_t imx_udc_irq(int irq, void *dev) 
		__func__, imx_usb->cfg, imx_usb->intf, imx_usb->alt,

		cfg, intf, alt);



		if (cfg != 1 && cfg != 2)

			goto end_irq;



		imx_usb->set_config = 0;

	if (cfg == 1 || cfg == 2) {



		/* Config setup */

		if (imx_usb->cfg != cfg) {

			D_REQ(imx_usb->dev,

					"<%s> Change config start\n", __func__);

			u.bRequest = USB_REQ_SET_CONFIGURATION;

			u.bRequestType = USB_DIR_OUT |

					USB_TYPE_STANDARD |
@@ -1085,16 +1048,10 @@ static irqreturn_t imx_udc_irq(int irq, void *dev) 
			u.wIndex = 0;

			u.wLength = 0;

			imx_usb->cfg = cfg;

			imx_usb->set_config = 1;

			imx_usb->driver->setup(&imx_usb->gadget, &u);

			imx_usb->set_config = 0;

			D_REQ(imx_usb->dev,

					"<%s> Change config done\n", __func__);



		}

		if (imx_usb->intf != intf || imx_usb->alt != alt) {

			D_REQ(imx_usb->dev,

				"<%s> Change interface start\n", __func__);

			u.bRequest = USB_REQ_SET_INTERFACE;

			u.bRequestType = USB_DIR_OUT |

					  USB_TYPE_STANDARD |
@@ -1104,14 +1061,30 @@ static irqreturn_t imx_udc_irq(int irq, void *dev) 
			u.wLength = 0;

			imx_usb->intf = intf;

			imx_usb->alt = alt;

			imx_usb->set_config = 1;

			imx_usb->driver->setup(&imx_usb->gadget, &u);

		}

	}



	imx_usb->set_config = 0;

			D_REQ(imx_usb->dev,

				"<%s> Change interface done\n", __func__);



	local_irq_enable();

}



static irqreturn_t imx_udc_irq(int irq, void *dev)

{

	struct imx_udc_struct *imx_usb = dev;

	int intr = __raw_readl(imx_usb->base + USB_INTR);

	int temp;



	if (intr & (INTR_WAKEUP | INTR_SUSPEND | INTR_RESUME | INTR_RESET_START

			| INTR_RESET_STOP | INTR_CFG_CHG)) {

				dump_intr(__func__, intr, imx_usb->dev);

				dump_usb_stat(__func__, imx_usb);

	}



	if (!imx_usb->driver)

		goto end_irq;



	if (intr & INTR_SOF) {

		/* Copy from Freescale BSP.

		   We must enable SOF intr and set CMDOVER.
@@ -1125,6 +1098,55 @@ static irqreturn_t imx_udc_irq(int irq, void *dev) 
		}

	}



	if (intr & INTR_CFG_CHG) {

		/* A workaround of serious IMX UDC bug.

		   Handling of CFG_CHG should be delayed for some time, because

		   IMX does not NACK the host when CFG_CHG interrupt is pending.

		   There is no time to handle current CFG_CHG

		   if next CFG_CHG or SETUP packed is send immediately.

		   We have to clear CFG_CHG, start the timer and

		   NACK the host by setting CTRL_CMDOVER

		   if it sends any SETUP packet.

		   When timer expires, handler is called to handle configuration

		   changes. While CFG_CHG is not handled (set_config=1),

		   we must NACK the host to every SETUP packed.

		   This delay prevents from going out of sync with host.

		 */

		__raw_writel(INTR_CFG_CHG, imx_usb->base + USB_INTR);

		imx_usb->set_config = 1;

		mod_timer(&imx_usb->timer, jiffies + 5);

		goto end_irq;

	}



	if (intr & INTR_WAKEUP) {

		if (imx_usb->gadget.speed == USB_SPEED_UNKNOWN

			&& imx_usb->driver && imx_usb->driver->resume)

				imx_usb->driver->resume(&imx_usb->gadget);

		imx_usb->set_config = 0;

		del_timer(&imx_usb->timer);

		imx_usb->gadget.speed = USB_SPEED_FULL;

	}



	if (intr & INTR_SUSPEND) {

		if (imx_usb->gadget.speed != USB_SPEED_UNKNOWN

			&& imx_usb->driver && imx_usb->driver->suspend)

				imx_usb->driver->suspend(&imx_usb->gadget);

		imx_usb->set_config = 0;

		del_timer(&imx_usb->timer);

		imx_usb->gadget.speed = USB_SPEED_UNKNOWN;

	}



	if (intr & INTR_RESET_START) {

		__raw_writel(intr, imx_usb->base + USB_INTR);

		udc_stop_activity(imx_usb, imx_usb->driver);

		imx_usb->set_config = 0;

		del_timer(&imx_usb->timer);

		imx_usb->gadget.speed = USB_SPEED_UNKNOWN;

	}



	if (intr & INTR_RESET_STOP)

		imx_usb->gadget.speed = USB_SPEED_FULL;



end_irq:

	__raw_writel(intr, imx_usb->base + USB_INTR);

	return IRQ_HANDLED;
@@ -1342,6 +1364,7 @@ int usb_gadget_unregister_driver(struct usb_gadget_driver *driver) 


	udc_stop_activity(imx_usb, driver);

	imx_udc_disable(imx_usb);

	del_timer(&imx_usb->timer);



	driver->unbind(&imx_usb->gadget);

	imx_usb->gadget.dev.driver = NULL;
@@ -1459,6 +1482,10 @@ static int __init imx_udc_probe(struct platform_device *pdev) 
	usb_init_data(imx_usb);

	imx_udc_init(imx_usb);



	init_timer(&imx_usb->timer);

	imx_usb->timer.function = handle_config;

	imx_usb->timer.data = (unsigned long)imx_usb;



	return 0;



fail3:
@@ -1481,6 +1508,7 @@ static int __exit imx_udc_remove(struct platform_device *pdev) 
	int i;



	imx_udc_disable(imx_usb);

	del_timer(&imx_usb->timer);



	for (i = 0; i < IMX_USB_NB_EP + 1; i++)

		free_irq(imx_usb->usbd_int[i], imx_usb);

drivers/usb/gadget/imx_udc.h

+1 −0
Original line number Diff line number Diff line
@@ -59,6 +59,7 @@ struct imx_udc_struct { 
	struct device				*dev;

	struct imx_ep_struct			imx_ep[IMX_USB_NB_EP];

	struct clk				*clk;

	struct timer_list			timer;

	enum ep0_state				ep0state;

	struct resource				*res;

	void __iomem				*base;