usb: musb: poll ID pin status in dual-role mode in mpfs glue layer

Similar to other platforms using the MUSB driver, PolarFire SoC lacks
an ID pin interrupt event, preventing several OTG-critical status
change events from being exposed. We need to rely on polling to detect
USB attach events for the dual-role port.

The otg state machine implementation is based on Texas Instruments
DA8xx/OMAP-L1x glue layer.

This has been tested on BeagleV-Fire with couple of devices in host mode
and with the Ethernet gadget driver in peripheral mode, in a wide
variety of plug orders.

Signed-off-by: Valentina Fernandez <valentina.fernandezalanis@microchip.com>
Link: https://lore.kernel.org/r/20240806131407.1542306-1-valentina.fernandezalanis@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Valentina Fernandez
2024-08-06 14:14:07 +01:00
committed by Greg Kroah-Hartman
parent 8952e50e16
commit 5cffefa1c1
+136 -24
View File
@@ -49,30 +49,6 @@ static const struct musb_hdrc_config mpfs_musb_hdrc_config = {
.ram_bits = MPFS_MUSB_RAM_BITS,
};
static irqreturn_t mpfs_musb_interrupt(int irq, void *__hci)
{
unsigned long flags;
irqreturn_t ret = IRQ_NONE;
struct musb *musb = __hci;
spin_lock_irqsave(&musb->lock, flags);
musb->int_usb = musb_readb(musb->mregs, MUSB_INTRUSB);
musb->int_tx = musb_readw(musb->mregs, MUSB_INTRTX);
musb->int_rx = musb_readw(musb->mregs, MUSB_INTRRX);
if (musb->int_usb || musb->int_tx || musb->int_rx) {
musb_writeb(musb->mregs, MUSB_INTRUSB, musb->int_usb);
musb_writew(musb->mregs, MUSB_INTRTX, musb->int_tx);
musb_writew(musb->mregs, MUSB_INTRRX, musb->int_rx);
ret = musb_interrupt(musb);
}
spin_unlock_irqrestore(&musb->lock, flags);
return ret;
}
static void mpfs_musb_set_vbus(struct musb *musb, int is_on)
{
u8 devctl;
@@ -111,6 +87,129 @@ static void mpfs_musb_set_vbus(struct musb *musb, int is_on)
musb_readb(musb->mregs, MUSB_DEVCTL));
}
#define POLL_SECONDS 2
static void otg_timer(struct timer_list *t)
{
struct musb *musb = from_timer(musb, t, dev_timer);
void __iomem *mregs = musb->mregs;
u8 devctl;
unsigned long flags;
/*
* We poll because PolarFire SoC won't expose several OTG-critical
* status change events (from the transceiver) otherwise.
*/
devctl = musb_readb(mregs, MUSB_DEVCTL);
dev_dbg(musb->controller, "Poll devctl %02x (%s)\n", devctl,
usb_otg_state_string(musb->xceiv->otg->state));
spin_lock_irqsave(&musb->lock, flags);
switch (musb->xceiv->otg->state) {
case OTG_STATE_A_WAIT_BCON:
devctl &= ~MUSB_DEVCTL_SESSION;
musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
if (devctl & MUSB_DEVCTL_BDEVICE) {
musb->xceiv->otg->state = OTG_STATE_B_IDLE;
MUSB_DEV_MODE(musb);
mod_timer(&musb->dev_timer, jiffies + POLL_SECONDS * HZ);
} else {
musb->xceiv->otg->state = OTG_STATE_A_IDLE;
MUSB_HST_MODE(musb);
}
break;
case OTG_STATE_A_WAIT_VFALL:
if (devctl & MUSB_DEVCTL_VBUS) {
mod_timer(&musb->dev_timer, jiffies + POLL_SECONDS * HZ);
break;
}
musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
break;
case OTG_STATE_B_IDLE:
/*
* There's no ID-changed IRQ, so we have no good way to tell
* when to switch to the A-Default state machine (by setting
* the DEVCTL.Session bit).
*
* Workaround: whenever we're in B_IDLE, try setting the
* session flag every few seconds. If it works, ID was
* grounded and we're now in the A-Default state machine.
*
* NOTE: setting the session flag is _supposed_ to trigger
* SRP but clearly it doesn't.
*/
musb_writeb(mregs, MUSB_DEVCTL, devctl | MUSB_DEVCTL_SESSION);
devctl = musb_readb(mregs, MUSB_DEVCTL);
if (devctl & MUSB_DEVCTL_BDEVICE)
mod_timer(&musb->dev_timer, jiffies + POLL_SECONDS * HZ);
else
musb->xceiv->otg->state = OTG_STATE_A_IDLE;
break;
default:
break;
}
spin_unlock_irqrestore(&musb->lock, flags);
}
static void __maybe_unused mpfs_musb_try_idle(struct musb *musb, unsigned long timeout)
{
static unsigned long last_timer;
if (timeout == 0)
timeout = jiffies + msecs_to_jiffies(3);
/* Never idle if active, or when VBUS timeout is not set as host */
if (musb->is_active || (musb->a_wait_bcon == 0 &&
musb->xceiv->otg->state == OTG_STATE_A_WAIT_BCON)) {
dev_dbg(musb->controller, "%s active, deleting timer\n",
usb_otg_state_string(musb->xceiv->otg->state));
del_timer(&musb->dev_timer);
last_timer = jiffies;
return;
}
if (time_after(last_timer, timeout) && timer_pending(&musb->dev_timer)) {
dev_dbg(musb->controller, "Longer idle timer already pending, ignoring...\n");
return;
}
last_timer = timeout;
dev_dbg(musb->controller, "%s inactive, starting idle timer for %u ms\n",
usb_otg_state_string(musb->xceiv->otg->state),
jiffies_to_msecs(timeout - jiffies));
mod_timer(&musb->dev_timer, timeout);
}
static irqreturn_t mpfs_musb_interrupt(int irq, void *__hci)
{
unsigned long flags;
irqreturn_t ret = IRQ_NONE;
struct musb *musb = __hci;
spin_lock_irqsave(&musb->lock, flags);
musb->int_usb = musb_readb(musb->mregs, MUSB_INTRUSB);
musb->int_tx = musb_readw(musb->mregs, MUSB_INTRTX);
musb->int_rx = musb_readw(musb->mregs, MUSB_INTRRX);
if (musb->int_usb || musb->int_tx || musb->int_rx) {
musb_writeb(musb->mregs, MUSB_INTRUSB, musb->int_usb);
musb_writew(musb->mregs, MUSB_INTRTX, musb->int_tx);
musb_writew(musb->mregs, MUSB_INTRRX, musb->int_rx);
ret = musb_interrupt(musb);
}
/* Poll for ID change */
if (musb->xceiv->otg->state == OTG_STATE_B_IDLE)
mod_timer(&musb->dev_timer, jiffies + POLL_SECONDS * HZ);
spin_unlock_irqrestore(&musb->lock, flags);
return ret;
}
static int mpfs_musb_init(struct musb *musb)
{
struct device *dev = musb->controller;
@@ -121,6 +220,8 @@ static int mpfs_musb_init(struct musb *musb)
return PTR_ERR(musb->xceiv);
}
timer_setup(&musb->dev_timer, otg_timer, 0);
musb->dyn_fifo = true;
musb->isr = mpfs_musb_interrupt;
@@ -129,13 +230,24 @@ static int mpfs_musb_init(struct musb *musb)
return 0;
}
static int mpfs_musb_exit(struct musb *musb)
{
del_timer_sync(&musb->dev_timer);
return 0;
}
static const struct musb_platform_ops mpfs_ops = {
.quirks = MUSB_DMA_INVENTRA,
.init = mpfs_musb_init,
.exit = mpfs_musb_exit,
.fifo_mode = 2,
#ifdef CONFIG_USB_INVENTRA_DMA
.dma_init = musbhs_dma_controller_create,
.dma_exit = musbhs_dma_controller_destroy,
#endif
#ifndef CONFIG_USB_MUSB_HOST
.try_idle = mpfs_musb_try_idle,
#endif
.set_vbus = mpfs_musb_set_vbus
};