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USB: imx_udc: Fix IMX UDC gadget general irq handling
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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: Darius Augulis <augulis.darius@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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Darius Augulis authored and Greg Kroah-Hartman committed Mar 24, 2009
1 parent d24921a commit b633d28
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Showing 2 changed files with 94 additions and 65 deletions.
158 changes: 93 additions & 65 deletions drivers/usb/gadget/imx_udc.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand Down Expand Up @@ -1013,70 +1014,32 @@ 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;
}

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;
local_irq_disable();

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;
alt = temp & STAT_ALTSET;
temp = __raw_readl(imx_usb->base + USB_STAT);
cfg = (temp & STAT_CFG) >> 5;
intf = (temp & STAT_INTF) >> 3;
alt = temp & STAT_ALTSET;

D_REQ(imx_usb->dev,
"<%s> orig config C=%d, I=%d, A=%d / "
"req config C=%d, I=%d, A=%d\n",
__func__, imx_usb->cfg, imx_usb->intf, imx_usb->alt,
cfg, intf, alt);
D_REQ(imx_usb->dev,
"<%s> orig config C=%d, I=%d, A=%d / "
"req config C=%d, I=%d, A=%d\n",
__func__, imx_usb->cfg, imx_usb->intf, imx_usb->alt,
cfg, intf, alt);

if (cfg != 1 && cfg != 2)
goto end_irq;
if (cfg == 1 || cfg == 2) {

imx_usb->set_config = 0;

/* 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 |
Expand All @@ -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 |
Expand All @@ -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__);
}
}

imx_usb->set_config = 0;

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.
Expand All @@ -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;
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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:
Expand All @@ -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);
Expand Down
1 change: 1 addition & 0 deletions drivers/usb/gadget/imx_udc.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down

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