这篇主要介绍 drivers/usb/musb/musb_host.c
在 musb_core.c 中的musb_init_controller（）函数中，调用了 allocate_instance()函数， 如下：
/* allocate */
musb = allocate_instance(dev, plat->config, ctrl);
if (!musb) {
status = -ENOMEM;
goto fail0;
} hcd = usb_create_hcd(&musb_hc_driver, dev, dev_name(dev)); //这篇主要介绍的就是这个 musb_hc_driver
if (!hcd)
return NULL;
/**
* usb_create_hcd - create and initialize an HCD structure
* @driver: HC driver that will use this hcd
* @dev: device for this HC, stored in hcd->self.controller
* @bus_name: value to store in hcd->self.bus_name
* Context: !in_interrupt()
*
* Allocate a struct usb_hcd, with extra space at the end for the
* HC driver's private data. Initialize the generic members of the
* hcd structure.
*
* If memory is unavailable, returns NULL.
*/
struct usb_hcd *usb_create_hcd (const struct hc_driver *driver,
struct device *dev, const char *bus_name)
{
struct usb_hcd *hcd;
hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL);
if (!hcd) {
dev_dbg (dev, "hcd alloc failed\n");
return NULL;
}
dev_set_drvdata(dev, hcd);
kref_init(&hcd->kref);
usb_bus_init(&hcd->self);
hcd->self.controller = dev;
hcd->self.bus_name = bus_name;
hcd->self.uses_dma = (dev->dma_mask != NULL);
init_timer(&hcd->rh_timer);
hcd->rh_timer.function = rh_timer_func;
hcd->rh_timer.data = (unsigned long) hcd;
#ifdef CONFIG_USB_SUSPEND
INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
#endif
mutex_init(&hcd->bandwidth_mutex);
hcd->driver = driver;
hcd->product_desc = (driver->product_desc) ? driver->product_desc :
"USB Host Controller";
return hcd;
}
EXPORT_SYMBOL_GPL(usb_create_hcd);1. 这篇的重点是 musb_hc_driver， 定义在/driver/usb/musb/musb_host.c中， 如下：
const struct hc_driver musb_hc_driver = {
.description = "musb-hcd",
.product_desc = "MUSB HDRC host driver", // product/vendor string
.hcd_priv_size = sizeof(struct musb), // size of private-data.
.flags = HCD_USB2 | HCD_MEMORY,
/* not using irq handler or reset hooks from usbcore, since
* those must be shared with peripheral code for OTG configs
*/
.start = musb_h_start,
.stop = musb_h_stop,
.get_frame_number = musb_h_get_frame_number,
.urb_enqueue = musb_urb_enqueue,
.urb_dequeue = musb_urb_dequeue,
.endpoint_disable = musb_h_disable,
.hub_status_data = musb_hub_status_data,
.hub_control = musb_hub_control,
.bus_suspend = musb_bus_suspend,
.bus_resume = musb_bus_resume,
/* .start_port_reset = NULL, */
/* .hub_irq_enable = NULL, */
};
1.1 flags 有如下一些选项：
int flags;
#define HCD_MEMORY 0x0001 /* HC regs use memory (else I/O) */
#define HCD_LOCAL_MEM 0x0002 /* HC needs local memory */
#define HCD_USB11 0x0010 /* USB 1.1 */
#define HCD_USB2 0x0020 /* USB 2.0 */
#define HCD_USB3 0x0040 /* USB 3.0 */
#define HCD_MASK 0x0070
2.1 static int musb_h_start(struct usb_hcd *hcd)
static int musb_h_start(struct usb_hcd *hcd)
{
struct musb *musb = hcd_to_musb(hcd);
/* NOTE: musb_start() is called when the hub driver turns
* on port power, or when (OTG) peripheral starts.
*/
hcd->state = HC_STATE_RUNNING;
musb->port1_status = 0;
return 0;
}
static inline struct musb *hcd_to_musb(struct usb_hcd *hcd)
{
return (struct musb *) (hcd->hcd_priv);
}
static void musb_h_stop(struct usb_hcd *hcd)
{
musb_stop(hcd_to_musb(hcd));
hcd->state = HC_STATE_HALT;
}
/*
* Make the HDRC stop (disable interrupts, etc.);
* reversible by musb_start
* called on gadget driver unregister
* with controller locked, irqs blocked
* acts as a NOP unless some role activated the hardware
*/
void musb_stop(struct musb *musb)
{
/* stop IRQs, timers, ... */
musb_platform_disable(musb);
musb_generic_disable(musb);
DBG(3, "HDRC disabled\n");
/* FIXME
* - mark host and/or peripheral drivers unusable/inactive
* - disable DMA (and enable it in HdrcStart)
* - make sure we can musb_start() after musb_stop(); with
* OTG mode, gadget driver module rmmod/modprobe cycles that
* - ...
*/
musb_platform_try_idle(musb, 0);
}
static int musb_h_get_frame_number(struct usb_hcd *hcd)
{
struct musb *musb = hcd_to_musb(hcd);
return musb_readw(musb->mregs, MUSB_FRAME);
}
4.1 musb_urb_enqueue():
static int musb_urb_enqueue(
struct usb_hcd *hcd,
struct urb *urb,
gfp_t mem_flags)
{
unsigned long flags;
struct musb *musb = hcd_to_musb(hcd);
struct usb_host_endpoint *hep = urb->ep;
struct musb_qh *qh;
struct usb_endpoint_descriptor *epd = &hep->desc;
int ret;
unsigned type_reg;
unsigned interval;
/* host role must be active */
if (!is_host_active(musb) || !musb->is_active)
return -ENODEV;
spin_lock_irqsave(&musb->lock, flags);
ret = usb_hcd_link_urb_to_ep(hcd, urb);
qh = ret ? NULL : hep->hcpriv;
if (qh)
urb->hcpriv = qh;
spin_unlock_irqrestore(&musb->lock, flags);
/* DMA mapping was already done, if needed, and this urb is on
* hep->urb_list now ... so we're done, unless hep wasn't yet
* scheduled onto a live qh.
*
* REVISIT best to keep hep->hcpriv valid until the endpoint gets
* disabled, testing for empty qh->ring and avoiding qh setup costs
* except for the first urb queued after a config change.
*/
if (qh || ret)
return ret;
/* Allocate and initialize qh, minimizing the work done each time
* hw_ep gets reprogrammed, or with irqs blocked. Then schedule it.
*
* REVISIT consider a dedicated qh kmem_cache, so it's harder
* for bugs in other kernel code to break this driver...
*/
qh = kzalloc(sizeof *qh, mem_flags);
if (!qh) {
spin_lock_irqsave(&musb->lock, flags);
usb_hcd_unlink_urb_from_ep(hcd, urb);
spin_unlock_irqrestore(&musb->lock, flags);
return -ENOMEM;
}
qh->hep = hep;
qh->dev = urb->dev;
INIT_LIST_HEAD(&qh->ring);
qh->is_ready = 1;
qh->maxpacket = le16_to_cpu(epd->wMaxPacketSize);
qh->type = usb_endpoint_type(epd);
/* Bits 11 & 12 of wMaxPacketSize encode high bandwidth multiplier.
* Some musb cores don't support high bandwidth ISO transfers; and
* we don't (yet!) support high bandwidth interrupt transfers.
*/
qh->hb_mult = 1 + ((qh->maxpacket >> 11) & 0x03);
if (qh->hb_mult > 1) {
int ok = (qh->type == USB_ENDPOINT_XFER_ISOC);
if (ok)
ok = (usb_pipein(urb->pipe) && musb->hb_iso_rx)
|| (usb_pipeout(urb->pipe) && musb->hb_iso_tx);
if (!ok) {
ret = -EMSGSIZE;
goto done;
}
qh->maxpacket &= 0x7ff;
}
qh->epnum = usb_endpoint_num(epd);
/* NOTE: urb->dev->devnum is wrong during SET_ADDRESS */
qh->addr_reg = (u8) usb_pipedevice(urb->pipe);
/* precompute rxtype/txtype/type0 register */
type_reg = (qh->type << 4) | qh->epnum;
switch (urb->dev->speed) { //判断传输速度
case USB_SPEED_LOW:
type_reg |= 0xc0;
break;
case USB_SPEED_FULL:
type_reg |= 0x80;
break;
default:
type_reg |= 0x40;
}
qh->type_reg = type_reg;
/* Precompute RXINTERVAL/TXINTERVAL register */
switch (qh->type) {
case USB_ENDPOINT_XFER_INT: //判断endpoint类型
/*
* Full/low speeds use the linear encoding,
* high speed uses the logarithmic encoding.
*/
if (urb->dev->speed <= USB_SPEED_FULL) {
interval = max_t(u8, epd->bInterval, 1);
break;
}
/* FALLTHROUGH */
case USB_ENDPOINT_XFER_ISOC:
/* ISO always uses logarithmic encoding */
interval = min_t(u8, epd->bInterval, 16);
break;
default:
/* REVISIT we actually want to use NAK limits, hinting to the
* transfer scheduling logic to try some other qh, e.g. try
* for 2 msec first:
*
* interval = (USB_SPEED_HIGH == urb->dev->speed) ? 16 : 2;
*
* The downside of disabling this is that transfer scheduling
* gets VERY unfair for nonperiodic transfers; a misbehaving
* peripheral could make that hurt. That's perfectly normal
* for reads from network or serial adapters ... so we have
* partial NAKlimit support for bulk RX.
*
* The upside of disabling it is simpler transfer scheduling.
*/
interval = 0;
}
qh->intv_reg = interval;
/* precompute addressing for external hub/tt ports */
if (musb->is_multipoint) {
struct usb_device *parent = urb->dev->parent;
if (parent != hcd->self.root_hub) {
qh->h_addr_reg = (u8) parent->devnum;
/* set up tt info if needed */
if (urb->dev->tt) {
qh->h_port_reg = (u8) urb->dev->ttport;
if (urb->dev->tt->hub)
qh->h_addr_reg =
(u8) urb->dev->tt->hub->devnum;
if (urb->dev->tt->multi)
qh->h_addr_reg |= 0x80;
}
}
}
/* invariant: hep->hcpriv is null OR the qh that's already scheduled.
* until we get real dma queues (with an entry for each urb/buffer),
* we only have work to do in the former case.
*/
spin_lock_irqsave(&musb->lock, flags);
if (hep->hcpriv) {
/* some concurrent activity submitted another urb to hep...
* odd, rare, error prone, but legal.
*/
kfree(qh);
qh = NULL;
ret = 0;
} else {
urb->hcpriv = qh;
ret = musb_schedule(musb, qh,
epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK);
}
/* By the time control returns here, urb may be
* completed back to the class driver. set urb->hcpriv before musb_schedule.
*/
if (ret != 0) {
urb->hcpriv = NULL;
/* FIXME set urb->start_frame for iso/intr, it's tested in
* musb_start_urb(), but otherwise only konicawc cares ...
*/
}
spin_unlock_irqrestore(&musb->lock, flags);
done:
if (ret != 0) {
spin_lock_irqsave(&musb->lock, flags);
usb_hcd_unlink_urb_from_ep(hcd, urb);
spin_unlock_irqrestore(&musb->lock, flags);
kfree(qh);
}
return ret;
}
struct musb *musb,
struct musb_qh *qh,
int is_in) -------------- 调度musb
/* schedule nodes correspond to peripheral endpoints, like an OHCI QH.
* the software schedule associates multiple such nodes with a given
* host side hardware endpoint + direction; scheduling may activate
* that hardware endpoint.
*/
static int musb_schedule(
struct musb *musb,
struct musb_qh *qh,
int is_in)
{
int idle = 0;
int best_diff;
int best_end, epnum;
struct musb_hw_ep *hw_ep = NULL;
struct list_head *head = NULL;
u8 toggle;
u8 txtype;
struct urb *urb = next_urb(qh);
/* use fixed hardware for control and bulk */
if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
head = &musb->control;
hw_ep = musb->control_ep;
goto success;
}
/* else, periodic transfers get muxed to other endpoints */
/*
* We know this qh hasn't been scheduled, so all we need to do
* is choose which hardware endpoint to put it on ...
*
* REVISIT what we really want here is a regular schedule tree
* like e.g. OHCI uses.
*/
best_diff = 4096;
best_end = -1;
for (epnum = 1, hw_ep = musb->endpoints + 1;
epnum < musb->nr_endpoints;
epnum++, hw_ep++) {
int diff;
if (musb_ep_get_qh(hw_ep, is_in) != NULL)
continue;
if (hw_ep == musb->bulk_ep)
continue;
if (is_in)
diff = hw_ep->max_packet_sz_rx;
else
diff = hw_ep->max_packet_sz_tx;
diff -= (qh->maxpacket * qh->hb_mult);
if (diff >= 0 && best_diff > diff) {
/*
* Mentor controller has a bug in that if we schedule
* a BULK Tx transfer on an endpoint that had earlier
* handled ISOC then the BULK transfer has to start on
* a zero toggle. If the BULK transfer starts on a 1
* toggle then this transfer will fail as the mentor
* controller starts the Bulk transfer on a 0 toggle
* irrespective of the programming of the toggle bits
* in the TXCSR register. Check for this condition
* while allocating the EP for a Tx Bulk transfer. If
* so skip this EP.
*/
hw_ep = musb->endpoints + epnum;
toggle = usb_gettoggle(urb->dev, qh->epnum, !is_in);
txtype = (musb_readb(hw_ep->regs, MUSB_TXTYPE)
>> 4) & 0x3;
if (!is_in && (qh->type == USB_ENDPOINT_XFER_BULK) &&
toggle && (txtype == USB_ENDPOINT_XFER_ISOC))
continue;
best_diff = diff;
best_end = epnum;
}
}
/* use bulk reserved ep1 if no other ep is free */
if (best_end < 0 && qh->type == USB_ENDPOINT_XFER_BULK) {
hw_ep = musb->bulk_ep;
if (is_in)
head = &musb->in_bulk;
else
head = &musb->out_bulk;
/* Enable bulk RX NAK timeout scheme when bulk requests are
* multiplexed. This scheme doen't work in high speed to full
* speed scenario as NAK interrupts are not coming from a
* full speed device connected to a high speed device.
* NAK timeout interval is 8 (128 uframe or 16ms) for HS and
* 4 (8 frame or 8ms) for FS device.
*/
if (is_in && qh->dev)
qh->intv_reg =
#ifdef CONFIG_ARCH_CARTESIO_STA2062
/*
* After introducing a delay to fix a race condition affecting
* the toggle flag in Cartesio STA2062 SoC's USB-FS controller,
* timeout interval needs to be relaxed. The check on dyn_fifo
* is to avoid introducing delay on HS-OTG controller as well.
*/
((USB_SPEED_HIGH == qh->dev->speed) ||
(!musb->config->dyn_fifo)) ? 8 : 4;
#else
(USB_SPEED_HIGH == qh->dev->speed) ? 8 : 4;
#endif
goto success;
} else if (best_end < 0) {
return -ENOSPC;
}
idle = 1;
qh->mux = 0;
hw_ep = musb->endpoints + best_end;
DBG(4, "qh %p periodic slot %d\n", qh, best_end);
success:
if (head) {
idle = list_empty(head);
list_add_tail(&qh->ring, head);
qh->mux = 1;
}
qh->hw_ep = hw_ep;
qh->hep->hcpriv = qh;
if (idle)
musb_start_urb(musb, is_in, qh);
return 0;
}
static struct musb_qh *musb_ep_get_qh(struct musb_hw_ep *ep, int is_in)
{
return is_in ? ep->in_qh : ep->out_qh;
}
static void
musb_start_urb(struct musb *musb, int is_in, struct musb_qh *qh) --- 开始传输
/*
* Start the URB at the front of an endpoint's queue
* end must be claimed from the caller.
*
* Context: controller locked, irqs blocked
*/
static void
musb_start_urb(struct musb *musb, int is_in, struct musb_qh *qh)
{
u16 frame;
u32 len;
void __iomem *mbase = musb->mregs;
struct urb *urb = next_urb(qh);
void *buf = urb->transfer_buffer;
u32 offset = 0;
struct musb_hw_ep *hw_ep = qh->hw_ep;
unsigned pipe = urb->pipe;
u8 address = usb_pipedevice(pipe);
int epnum = hw_ep->epnum;
/* initialize software qh state */
qh->offset = 0;
qh->segsize = 0;
/* gather right source of data */
switch (qh->type) {
case USB_ENDPOINT_XFER_CONTROL:
/* control transfers always start with SETUP */
is_in = 0;
musb->ep0_stage = MUSB_EP0_START;
buf = urb->setup_packet;
len = 8;
break;
case USB_ENDPOINT_XFER_ISOC:
qh->iso_idx = 0;
qh->frame = 0;
offset = urb->iso_frame_desc[0].offset;
len = urb->iso_frame_desc[0].length;
break;
default: /* bulk, interrupt */
/* actual_length may be nonzero on retry paths */
buf = urb->transfer_buffer + urb->actual_length;
len = urb->transfer_buffer_length - urb->actual_length;
}
DBG(4, "qh %p urb %p dev%d ep%d%s%s, hw_ep %d, %p/%d\n",
qh, urb, address, qh->epnum,
is_in ? "in" : "out",
({char *s; switch (qh->type) {
case USB_ENDPOINT_XFER_CONTROL: s = ""; break;
case USB_ENDPOINT_XFER_BULK: s = "-bulk"; break;
case USB_ENDPOINT_XFER_ISOC: s = "-iso"; break;
default: s = "-intr"; break;
}; s; }),
epnum, buf + offset, len);
/* Configure endpoint */
musb_ep_set_qh(hw_ep, is_in, qh);
musb_ep_program(musb, epnum, urb, !is_in, buf, offset, len);
/* transmit may have more work: start it when it is time */
if (is_in)
return;
/* determine if the time is right for a periodic transfer */
switch (qh->type) {
case USB_ENDPOINT_XFER_ISOC:
case USB_ENDPOINT_XFER_INT:
DBG(3, "check whether there's still time for periodic Tx\n");
frame = musb_readw(mbase, MUSB_FRAME);
/* FIXME this doesn't implement that scheduling policy ...
* or handle framecounter wrapping
*/
if ((urb->transfer_flags & URB_ISO_ASAP)
|| (frame >= urb->start_frame)) {
/* REVISIT the SOF irq handler shouldn't duplicate
* this code; and we don't init urb->start_frame...
*/
qh->frame = 0;
goto start;
} else {
qh->frame = urb->start_frame;
/* enable SOF interrupt so we can count down */
DBG(1, "SOF for %d\n", epnum);
#if 1 /* ifndef CONFIG_ARCH_DAVINCI */
musb_writeb(mbase, MUSB_INTRUSBE, 0xff);
#endif
}
break;
default:
start:
DBG(4, "Start TX%d %s\n", epnum,
hw_ep->tx_channel ? "dma" : "pio");
if (!hw_ep->tx_channel)
musb_h_tx_start(hw_ep);
else if (is_cppi_enabled() || tusb_dma_omap())
musb_h_tx_dma_start(hw_ep);
}
}
struct urb *urb, int is_out,
u8 *buf, u32 offset, u32 len)
/*
* Program an HDRC endpoint as per the given URB
* Context: irqs blocked, controller lock held
*/
static void musb_ep_program(struct musb *musb, u8 epnum,
struct urb *urb, int is_out,
u8 *buf, u32 offset, u32 len)
{
struct dma_controller *dma_controller;
struct dma_channel *dma_channel;
u8 dma_ok;
void __iomem *mbase = musb->mregs;
struct musb_hw_ep *hw_ep = musb->endpoints + epnum;
void __iomem *epio = hw_ep->regs;
struct musb_qh *qh = musb_ep_get_qh(hw_ep, !is_out);
u16 packet_sz = qh->maxpacket;
DBG(3, "%s hw%d urb %p spd%d dev%d ep%d%s "
"h_addr%02x h_port%02x bytes %d\n",
is_out ? "-->" : "<--",
epnum, urb, urb->dev->speed,
qh->addr_reg, qh->epnum, is_out ? "out" : "in",
qh->h_addr_reg, qh->h_port_reg,
len);
musb_ep_select(mbase, epnum);
/* candidate for DMA? */
dma_controller = musb->dma_controller;
if (is_dma_capable() && epnum && dma_controller) {
dma_channel = is_out ? hw_ep->tx_channel : hw_ep->rx_channel;
if (!dma_channel) {
dma_channel = dma_controller->channel_alloc(
dma_controller, hw_ep, is_out);
if (is_out)
hw_ep->tx_channel = dma_channel;
else
hw_ep->rx_channel = dma_channel;
}
} else
dma_channel = NULL;
/* make sure we clear DMAEnab, autoSet bits from previous run */
/* OUT/transmit/EP0 or IN/receive? */
if (is_out) {
u16 csr;
u16 int_txe;
u16 load_count;
csr = musb_readw(epio, MUSB_TXCSR);
/* disable interrupt in case we flush */
int_txe = musb_readw(mbase, MUSB_INTRTXE);
musb_writew(mbase, MUSB_INTRTXE, int_txe & ~(1 << epnum));
/* general endpoint setup */
if (epnum) {
/* flush all old state, set default */
musb_h_tx_flush_fifo(hw_ep);
/*
* We must not clear the DMAMODE bit before or in
* the same cycle with the DMAENAB bit, so we clear
* the latter first...
*/
csr &= ~(MUSB_TXCSR_H_NAKTIMEOUT
| MUSB_TXCSR_AUTOSET
| MUSB_TXCSR_DMAENAB
| MUSB_TXCSR_FRCDATATOG
| MUSB_TXCSR_H_RXSTALL
| MUSB_TXCSR_H_ERROR
| MUSB_TXCSR_TXPKTRDY
);
csr |= MUSB_TXCSR_MODE;
if (usb_gettoggle(urb->dev, qh->epnum, 1))
csr |= MUSB_TXCSR_H_WR_DATATOGGLE
| MUSB_TXCSR_H_DATATOGGLE;
else
csr |= MUSB_TXCSR_CLRDATATOG;
musb_writew(epio, MUSB_TXCSR, csr);
/* REVISIT may need to clear FLUSHFIFO ... */
csr &= ~MUSB_TXCSR_DMAMODE;
musb_writew(epio, MUSB_TXCSR, csr);
csr = musb_readw(epio, MUSB_TXCSR);
} else {
/* endpoint 0: just flush */
musb_h_ep0_flush_fifo(hw_ep);
}
/* target addr and (for multipoint) hub addr/port */
if (musb->is_multipoint) {
musb_write_txfunaddr(mbase, epnum, qh->addr_reg);
musb_write_txhubaddr(mbase, epnum, qh->h_addr_reg);
musb_write_txhubport(mbase, epnum, qh->h_port_reg);
/* FIXME if !epnum, do the same for RX ... */
} else
musb_writeb(mbase, MUSB_FADDR, qh->addr_reg);
/* protocol/endpoint/interval/NAKlimit */
if (epnum) {
musb_writeb(epio, MUSB_TXTYPE, qh->type_reg);
if (can_bulk_split(musb, qh->type))
musb_writew(epio, MUSB_TXMAXP,
packet_sz
| ((hw_ep->max_packet_sz_tx /
packet_sz) - 1) << 11);
else
musb_writew(epio, MUSB_TXMAXP,
packet_sz);
musb_writeb(epio, MUSB_TXINTERVAL, qh->intv_reg);
} else {
musb_writeb(epio, MUSB_NAKLIMIT0, qh->intv_reg);
if (musb->is_multipoint)
musb_writeb(epio, MUSB_TYPE0,
qh->type_reg);
}
if (can_bulk_split(musb, qh->type))
load_count = min((u32) hw_ep->max_packet_sz_tx,
len);
else
load_count = min((u32) packet_sz, len);
if (dma_channel && musb_tx_dma_program(dma_controller,
hw_ep, qh, urb, offset, len))
load_count = 0;
if (load_count) {
/* PIO to load FIFO */
qh->segsize = load_count;
musb_write_fifo(hw_ep, load_count, buf);
}
/* re-enable interrupt */
musb_writew(mbase, MUSB_INTRTXE, int_txe);
/* IN/receive */
} else {
u16 csr = 0;
#ifdef CONFIG_USB_CARTESIO_DMA
uint16_t rx_count = musb_readw(hw_ep->regs, MUSB_RXCOUNT);
/* In case of DMA mode 1, we are receiving the last packet even before
programming it. This logic checks for the received data and return
it to class driver. */
if(usb_pipebulk(urb->pipe))
{
csr = musb_readw(hw_ep->regs,MUSB_RXCSR);
if (csr & MUSB_RXCSR_RXPKTRDY)
{
uint16_t rx_count = musb_readw(hw_ep->regs, MUSB_RXCOUNT);
int done = false;
DBG(4, "reading residual rx_count = %d packet_size = %x\n", rx_count, packet_sz);
if(rx_count < packet_sz) {
done = musb_host_packet_rx(musb,urb,epnum,false);
DBG(4,"residual found done=%d\n", done);
if (done) {
urb->status = 0;
musb_advance_schedule(musb, urb, hw_ep, USB_DIR_IN);
DBG(4,"RX short packet exit\n");
return;
}
}
}
}
if (hw_ep->rx_reinit && (!hw_ep->is_reqpkt_clear)) {
#else
if (hw_ep->rx_reinit) {
#endif
musb_rx_reinit(musb, qh, hw_ep);
/* init new state: toggle and NYET, maybe DMA later */
if (usb_gettoggle(urb->dev, qh->epnum, 0))
csr = MUSB_RXCSR_H_WR_DATATOGGLE
| MUSB_RXCSR_H_DATATOGGLE;
else
csr = 0;
if (qh->type == USB_ENDPOINT_XFER_INT)
csr |= MUSB_RXCSR_DISNYET;
}
#ifndef CONFIG_USB_CARTESIO_DMA
else {
csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
if (csr & (MUSB_RXCSR_RXPKTRDY
| MUSB_RXCSR_DMAENAB
| MUSB_RXCSR_H_REQPKT))
ERR("broken !rx_reinit, ep%d csr %04x\n",
hw_ep->epnum, csr);
/* scrub any stale state, leaving toggle alone */
csr &= MUSB_RXCSR_DISNYET;
}
#endif
/* kick things off */
if ((is_cppi_enabled() || tusb_dma_omap() ||
is_cartesio_dma_enabled()) && dma_channel) {
/* candidate for DMA */
#ifdef CONFIG_USB_CARTESIO_DMA
/* len=192 special case to avoid warning in case of usb1.1 drives */
if((usb_pipebulk(urb->pipe)) && ((len < packet_sz) || (len == 192))) {
DBG(4, "Program RX in PIO mode\n");
dma_controller->channel_release(dma_channel);
hw_ep->rx_channel = NULL;
goto PIO;
}
#endif
if (dma_channel) {
dma_channel->actual_len = 0L;
qh->segsize = len;
/* unless caller treats short rx transfers as
* errors, we dare not queue multiple transfers.
*/
dma_ok = dma_controller->channel_program(
dma_channel, packet_sz,
!(urb->transfer_flags
& URB_SHORT_NOT_OK),
urb->transfer_dma + offset,
qh->segsize);
if (!dma_ok) {
dma_controller->channel_release(
dma_channel);
hw_ep->rx_channel = NULL;
dma_channel = NULL;
} else {
#ifdef CONFIG_USB_CARTESIO_DMA
/* Program in DMA mode mode 1. issue with DMA mode 0*/
csr |= MUSB_RXCSR_DMAENAB | MUSB_RXCSR_AUTOCLEAR
| MUSB_RXCSR_DMAMODE | MUSB_RXCSR_H_AUTOREQ;
#else
csr |= MUSB_RXCSR_DMAENAB;
#endif
}
}
}
/* setting RXCSR multiple time leads to some random behaviour */
#ifdef CONFIG_USB_CARTESIO_DMA
PIO :
if((!hw_ep->is_reqpkt_clear) || !(rx_count)) {
#endif
csr |= MUSB_RXCSR_H_REQPKT;
DBG(7, "RXCSR%d := %04x\n", epnum, csr);
musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
#ifdef CONFIG_USB_CARTESIO_DMA
}
#endif
}
}
static void musb_h_tx_flush_fifo(struct musb_hw_ep *ep)
/*
* Clear TX fifo. Needed to avoid BABBLE errors.
*/
static void musb_h_tx_flush_fifo(struct musb_hw_ep *ep)
{
void __iomem *epio = ep->regs;
u16 csr;
u16 lastcsr = 0;
int retries = 1000;
csr = musb_readw(epio, MUSB_TXCSR);
while (csr & MUSB_TXCSR_FIFONOTEMPTY) {
if (csr != lastcsr)
DBG(3, "Host TX FIFONOTEMPTY csr: %02x\n", csr);
lastcsr = csr;
csr |= MUSB_TXCSR_FLUSHFIFO;
musb_writew(epio, MUSB_TXCSR, csr);
csr = musb_readw(epio, MUSB_TXCSR);
if (WARN(retries-- < 1,
"Could not flush host TX%d fifo: csr: %04x\n",
ep->epnum, csr))
return;
mdelay(1);
}
}
static void musb_h_ep0_flush_fifo(struct musb_hw_ep *ep)
{
void __iomem *epio = ep->regs;
u16 csr;
int retries = 5;
/* scrub any data left in the fifo */
do {
csr = musb_readw(epio, MUSB_TXCSR);
if (!(csr & (MUSB_CSR0_TXPKTRDY | MUSB_CSR0_RXPKTRDY)))
break;
musb_writew(epio, MUSB_TXCSR, MUSB_CSR0_FLUSHFIFO);
csr = musb_readw(epio, MUSB_TXCSR);
udelay(10);
} while (--retries);
WARN(!retries, "Could not flush host TX%d fifo: csr: %04x\n",
ep->epnum, csr);
/* and reset for the next transfer */
musb_writew(epio, MUSB_TXCSR, 0);
}
musb_rx_reinit(struct musb *musb, struct musb_qh *qh, struct musb_hw_ep *ep) --重新开始接收
/* we don't always need to reinit a given side of an endpoint...
* when we do, use tx/rx reinit routine and then construct a new CSR
* to address data toggle, NYET, and DMA or PIO.
*
* it's possible that driver bugs (especially for DMA) or aborting a
* transfer might have left the endpoint busier than it should be.
* the busy/not-empty tests are basically paranoia.
*/
static void
musb_rx_reinit(struct musb *musb, struct musb_qh *qh, struct musb_hw_ep *ep)
{
u16 csr;
/* NOTE: we know the "rx" fifo reinit never triggers for ep0.
* That always uses tx_reinit since ep0 repurposes TX register
* offsets; the initial SETUP packet is also a kind of OUT.
*/
/* if programmed for Tx, put it in RX mode */
if (ep->is_shared_fifo) {
csr = musb_readw(ep->regs, MUSB_TXCSR);
if (csr & MUSB_TXCSR_MODE) {
musb_h_tx_flush_fifo(ep);
csr = musb_readw(ep->regs, MUSB_TXCSR);
musb_writew(ep->regs, MUSB_TXCSR,
csr | MUSB_TXCSR_FRCDATATOG);
}
/*
* Clear the MODE bit (and everything else) to enable Rx.
* NOTE: we mustn't clear the DMAMODE bit before DMAENAB.
*/
if (csr & MUSB_TXCSR_DMAMODE)
musb_writew(ep->regs, MUSB_TXCSR, MUSB_TXCSR_DMAMODE);
musb_writew(ep->regs, MUSB_TXCSR, 0);
/* scrub all previous state, clearing toggle */
} else {
csr = musb_readw(ep->regs, MUSB_RXCSR);
if (csr & MUSB_RXCSR_RXPKTRDY)
WARNING("rx%d, packet/%d ready?\n", ep->epnum,
musb_readw(ep->regs, MUSB_RXCOUNT));
musb_h_flush_rxfifo(ep, MUSB_RXCSR_CLRDATATOG);
}
/* target addr and (for multipoint) hub addr/port */
if (musb->is_multipoint) {
musb_write_rxfunaddr(ep->target_regs, qh->addr_reg);
musb_write_rxhubaddr(ep->target_regs, qh->h_addr_reg);
musb_write_rxhubport(ep->target_regs, qh->h_port_reg);
} else
musb_writeb(musb->mregs, MUSB_FADDR, qh->addr_reg);
/* protocol/endpoint, interval/NAKlimit, i/o size */
musb_writeb(ep->regs, MUSB_RXTYPE, qh->type_reg);
musb_writeb(ep->regs, MUSB_RXINTERVAL, qh->intv_reg);
/* NOTE: bulk combining rewrites high bits of maxpacket */
/* Set RXMAXP with the FIFO size of the endpoint
* to disable double buffer mode.
*/
if (musb->hwvers < MUSB_HWVERS_2000)
musb_writew(ep->regs, MUSB_RXMAXP, ep->max_packet_sz_rx);
else
musb_writew(ep->regs, MUSB_RXMAXP,
qh->maxpacket | ((qh->hb_mult - 1) << 11));
ep->rx_reinit = 0;
}
static int musb_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
{
struct musb *musb = hcd_to_musb(hcd);
struct musb_qh *qh;
unsigned long flags;
int is_in = usb_pipein(urb->pipe);
int ret;
DBG(4, "urb=%p, dev%d ep%d%s\n", urb,
usb_pipedevice(urb->pipe),
usb_pipeendpoint(urb->pipe),
is_in ? "in" : "out");
spin_lock_irqsave(&musb->lock, flags);
ret = usb_hcd_check_unlink_urb(hcd, urb, status); //check whether an URB may be unlinked
if (ret)
goto done;
qh = urb->hcpriv;
if (!qh)
goto done;
/*
* Any URB not actively programmed into endpoint hardware can be
* immediately given back; that's any URB not at the head of an
* endpoint queue, unless someday we get real DMA queues. And even
* if it's at the head, it might not be known to the hardware...
*
* Otherwise abort current transfer, pending DMA, etc.; urb->status
* has already been updated. This is a synchronous abort; it'd be
* OK to hold off until after some IRQ, though.
*
* NOTE: qh is invalid unless !list_empty(&hep->urb_list)
*/
if (!qh->is_ready
|| urb->urb_list.prev != &qh->hep->urb_list
|| musb_ep_get_qh(qh->hw_ep, is_in) != qh) {
int ready = qh->is_ready;
qh->is_ready = 0;
musb_giveback(musb, urb, 0);
qh->is_ready = ready;
/* If nothing else (usually musb_giveback) is using it
* and its URB list has emptied, recycle this qh.
*/
if (ready && list_empty(&qh->hep->urb_list)) {
qh->hep->hcpriv = NULL;
list_del(&qh->ring);
kfree(qh);
}
} else
ret = musb_cleanup_urb(urb, qh);
done:
spin_unlock_irqrestore(&musb->lock, flags);
return ret;
}
/*
* abort a transfer that's at the head of a hardware queue.
* called with controller locked, irqs blocked
* that hardware queue advances to the next transfer, unless prevented
*/
static int musb_cleanup_urb(struct urb *urb, struct musb_qh *qh)
{
struct musb_hw_ep *ep = qh->hw_ep;
void __iomem *epio = ep->regs;
unsigned hw_end = ep->epnum;
void __iomem *regs = ep->musb->mregs;
int is_in = usb_pipein(urb->pipe);
int status = 0;
u16 csr;
musb_ep_select(regs, hw_end);
if (is_dma_capable()) {
struct dma_channel *dma;
dma = is_in ? ep->rx_channel : ep->tx_channel;
if (dma) {
status = ep->musb->dma_controller->channel_abort(dma);
DBG(status ? 1 : 3,
"abort %cX%d DMA for urb %p --> %d\n",
is_in ? 'R' : 'T', ep->epnum,
urb, status);
urb->actual_length += dma->actual_len;
}
}
/* turn off DMA requests, discard state, stop polling ... */
if (is_in) {
/* giveback saves bulk toggle */
csr = musb_h_flush_rxfifo(ep, 0);
/* REVISIT we still get an irq; should likely clear the
* endpoint's irq status here to avoid bogus irqs.
* clearing that status is platform-specific...
*/
} else if (ep->epnum) {
musb_h_tx_flush_fifo(ep);
csr = musb_readw(epio, MUSB_TXCSR);
csr &= ~(MUSB_TXCSR_AUTOSET
| MUSB_TXCSR_DMAENAB
| MUSB_TXCSR_H_RXSTALL
| MUSB_TXCSR_H_NAKTIMEOUT
| MUSB_TXCSR_H_ERROR
| MUSB_TXCSR_TXPKTRDY);
musb_writew(epio, MUSB_TXCSR, csr);
/* REVISIT may need to clear FLUSHFIFO ... */
musb_writew(epio, MUSB_TXCSR, csr);
/* flush cpu writebuffer */
csr = musb_readw(epio, MUSB_TXCSR);
} else {
musb_h_ep0_flush_fifo(ep);
}
if (status == 0)
musb_advance_schedule(ep->musb, urb, ep, is_in);
return status;
}
struct musb_hw_ep *hw_ep, int is_in)
/*
* Advance this hardware endpoint's queue, completing the specified URB and
* advancing to either the next URB queued to that qh, or else invalidating
* that qh and advancing to the next qh scheduled after the current one.
*
* Context: caller owns controller lock, IRQs are blocked
*/
static void musb_advance_schedule(struct musb *musb, struct urb *urb,
struct musb_hw_ep *hw_ep, int is_in)
{
struct musb_qh *qh = musb_ep_get_qh(hw_ep, is_in);
struct musb_hw_ep *ep = qh->hw_ep;
int ready = qh->is_ready;
int status;
status = (urb->status == -EINPROGRESS) ? 0 : urb->status;
/* save toggle eagerly, for paranoia */
switch (qh->type) {
case USB_ENDPOINT_XFER_BULK:
case USB_ENDPOINT_XFER_INT:
musb_save_toggle(qh, is_in, urb);
break;
case USB_ENDPOINT_XFER_ISOC:
if (status == 0 && urb->error_count)
status = -EXDEV;
break;
}
qh->is_ready = 0;
musb_giveback(musb, urb, status);
qh->is_ready = ready;
/* reclaim resources (and bandwidth) ASAP; deschedule it, and
* invalidate qh as soon as list_empty(&hep->urb_list)
*/
if (list_empty(&qh->hep->urb_list)) {
struct list_head *head;
if (is_in)
ep->rx_reinit = 1;
else
ep->tx_reinit = 1;
/* Clobber old pointers to this qh */
musb_ep_set_qh(ep, is_in, NULL);
qh->hep->hcpriv = NULL;
switch (qh->type) {
case USB_ENDPOINT_XFER_CONTROL:
case USB_ENDPOINT_XFER_BULK:
/* fifo policy for these lists, except that NAKing
* should rotate a qh to the end (for fairness).
*/
if (qh->mux == 1) {
head = qh->ring.prev;
list_del(&qh->ring);
kfree(qh);
qh = first_qh(head);
break;
}
case USB_ENDPOINT_XFER_ISOC:
case USB_ENDPOINT_XFER_INT:
/* this is where periodic bandwidth should be
* de-allocated if it's tracked and allocated;
* and where we'd update the schedule tree...
*/
kfree(qh);
qh = NULL;
break;
}
}
if (qh != NULL && qh->is_ready) {
DBG(4, "... next ep%d %cX urb %p\n",
hw_ep->epnum, is_in ? 'R' : 'T', next_urb(qh));
musb_start_urb(musb, is_in, qh);
}
}
static void musb_ep_set_qh(struct musb_hw_ep *ep, int is_in, struct musb_qh *qh)
{
if (is_in != 0 || ep->is_shared_fifo)
ep->in_qh = qh;
if (is_in == 0 || ep->is_shared_fifo)
ep->out_qh = qh;
}
musb_h_disable(struct usb_hcd *hcd, struct usb_host_endpoint *hep)
/* disable an endpoint */
static void
musb_h_disable(struct usb_hcd *hcd, struct usb_host_endpoint *hep)
{
u8 is_in = hep->desc.bEndpointAddress & USB_DIR_IN;
unsigned long flags;
struct musb *musb = hcd_to_musb(hcd);
struct musb_qh *qh;
struct urb *urb;
spin_lock_irqsave(&musb->lock, flags);
qh = hep->hcpriv;
if (qh == NULL)
goto exit;
/* NOTE: qh is invalid unless !list_empty(&hep->urb_list) */
/* Kick the first URB off the hardware, if needed */
qh->is_ready = 0;
if (musb_ep_get_qh(qh->hw_ep, is_in) == qh) {
urb = next_urb(qh);
/* make software (then hardware) stop ASAP */
if (!urb->unlinked)
urb->status = -ESHUTDOWN;
/* cleanup */
musb_cleanup_urb(urb, qh);
/* Then nuke all the others ... and advance the
* queue on hw_ep (e.g. bulk ring) when we're done.
*/
while (!list_empty(&hep->urb_list)) {
urb = next_urb(qh);
urb->status = -ESHUTDOWN;
musb_advance_schedule(musb, urb, qh->hw_ep, is_in);
}
} else {
/* Just empty the queue; the hardware is busy with
* other transfers, and since !qh->is_ready nothing
* will activate any of these as it advances.
*/
while (!list_empty(&hep->urb_list))
musb_giveback(musb, next_urb(qh), -ESHUTDOWN);
hep->hcpriv = NULL;
list_del(&qh->ring);
kfree(qh);
}
exit:
spin_unlock_irqrestore(&musb->lock, flags);
}
6.1 int musb_hub_status_data(struct usb_hcd *hcd, char *buf) --- 在 drivers/usb/musb/musb_virthub.c 中
/* Caller may or may not hold musb->lock */
int musb_hub_status_data(struct usb_hcd *hcd, char *buf)
{
struct musb *musb = hcd_to_musb(hcd);
int retval = 0;
/* called in_irq() via usb_hcd_poll_rh_status() */
if (musb->port1_status & 0xffff0000) {
*buf = 0x02;
retval = 1;
}
return retval;
}
struct usb_hcd *hcd,
u16 typeReq,
u16 wValue,
u16 wIndex,
char *buf,
u16 wLength)
int musb_hub_control(
struct usb_hcd *hcd,
u16 typeReq,
u16 wValue,
u16 wIndex,
char *buf,
u16 wLength)
{
struct musb *musb = hcd_to_musb(hcd);
u32 temp;
int retval = 0;
unsigned long flags;
spin_lock_irqsave(&musb->lock, flags);
if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))) {
spin_unlock_irqrestore(&musb->lock, flags);
return -ESHUTDOWN;
}
/* hub features: always zero, setting is a NOP
* port features: reported, sometimes updated when host is active
* no indicators
*/
switch (typeReq) {
case ClearHubFeature:
case SetHubFeature:
switch (wValue) {
case C_HUB_OVER_CURRENT:
case C_HUB_LOCAL_POWER:
break;
default:
goto error;
}
break;
case ClearPortFeature:
if ((wIndex & 0xff) != 1)
goto error;
switch (wValue) {
case USB_PORT_FEAT_ENABLE:
break;
case USB_PORT_FEAT_SUSPEND:
musb_port_suspend(musb, false);
break;
case USB_PORT_FEAT_POWER:
if (!(is_otg_enabled(musb) && hcd->self.is_b_host))
musb_set_vbus(musb, 0);
break;
case USB_PORT_FEAT_C_CONNECTION:
case USB_PORT_FEAT_C_ENABLE:
case USB_PORT_FEAT_C_OVER_CURRENT:
case USB_PORT_FEAT_C_RESET:
case USB_PORT_FEAT_C_SUSPEND:
break;
default:
goto error;
}
DBG(5, "clear feature %d\n", wValue);
musb->port1_status &= ~(1 << wValue);
break;
case GetHubDescriptor:
{
struct usb_hub_descriptor *desc = (void *)buf;
desc->bDescLength = 9;
desc->bDescriptorType = 0x29;
desc->bNbrPorts = 1;
desc->wHubCharacteristics = cpu_to_le16(
0x0001 /* per-port power switching */
| 0x0010 /* no overcurrent reporting */
);
desc->bPwrOn2PwrGood = 5; /* msec/2 */
desc->bHubContrCurrent = 0;
/* workaround bogus struct definition */
desc->DeviceRemovable[0] = 0x02; /* port 1 */
desc->DeviceRemovable[1] = 0xff;
}
break;
case GetHubStatus:
temp = 0;
*(__le32 *) buf = cpu_to_le32(temp);
break;
case GetPortStatus:
if (wIndex != 1)
goto error;
/* finish RESET signaling? */
if ((musb->port1_status & USB_PORT_STAT_RESET)
&& time_after_eq(jiffies, musb->rh_timer))
musb_port_reset(musb, false);
/* finish RESUME signaling? */
if ((musb->port1_status & MUSB_PORT_STAT_RESUME)
&& time_after_eq(jiffies, musb->rh_timer)) {
u8 power;
power = musb_readb(musb->mregs, MUSB_POWER);
power &= ~MUSB_POWER_RESUME;
DBG(4, "root port resume stopped, power %02x\n",
power);
musb_writeb(musb->mregs, MUSB_POWER, power);
/* ISSUE: DaVinci (RTL 1.300) disconnects after
* resume of high speed peripherals (but not full
* speed ones).
*/
musb->is_active = 1;
musb->port1_status &= ~(USB_PORT_STAT_SUSPEND
| MUSB_PORT_STAT_RESUME);
musb->port1_status |= USB_PORT_STAT_C_SUSPEND << 16;
usb_hcd_poll_rh_status(musb_to_hcd(musb));
/* NOTE: it might really be A_WAIT_BCON ... */
musb->xceiv->state = OTG_STATE_A_HOST;
}
put_unaligned(cpu_to_le32(musb->port1_status
& ~MUSB_PORT_STAT_RESUME),
(__le32 *) buf);
/* port change status is more interesting */
DBG(get_unaligned((u16 *)(buf+2)) ? 2 : 5, "port status %08x\n",
musb->port1_status);
break;
case SetPortFeature:
if ((wIndex & 0xff) != 1)
goto error;
switch (wValue) {
case USB_PORT_FEAT_POWER:
/* NOTE: this controller has a strange state machine
* that involves "requesting sessions" according to
* magic side effects from incompletely-described
* rules about startup...
*
* This call is what really starts the host mode; be
* very careful about side effects if you reorder any
* initialization logic, e.g. for OTG, or change any
* logic relating to VBUS power-up.
*/
if (!(is_otg_enabled(musb) && hcd->self.is_b_host))
musb_start(musb);
break;
case USB_PORT_FEAT_RESET:
musb_port_reset(musb, true);
break;
case USB_PORT_FEAT_SUSPEND:
musb_port_suspend(musb, true);
break;
case USB_PORT_FEAT_TEST:
if (unlikely(is_host_active(musb)))
goto error;
wIndex >>= 8;
switch (wIndex) {
case 1:
pr_debug("TEST_J\n");
temp = MUSB_TEST_J;
break;
case 2:
pr_debug("TEST_K\n");
temp = MUSB_TEST_K;
break;
case 3:
pr_debug("TEST_SE0_NAK\n");
temp = MUSB_TEST_SE0_NAK;
break;
case 4:
pr_debug("TEST_PACKET\n");
temp = MUSB_TEST_PACKET;
musb_load_testpacket(musb);
break;
case 5:
pr_debug("TEST_FORCE_ENABLE\n");
temp = MUSB_TEST_FORCE_HOST
| MUSB_TEST_FORCE_HS;
musb_writeb(musb->mregs, MUSB_DEVCTL,
MUSB_DEVCTL_SESSION);
break;
case 6:
pr_debug("TEST_FIFO_ACCESS\n");
temp = MUSB_TEST_FIFO_ACCESS;
break;
default:
goto error;
}
musb_writeb(musb->mregs, MUSB_TESTMODE, temp);
break;
default:
goto error;
}
DBG(5, "set feature %d\n", wValue);
musb->port1_status |= 1 << wValue;
break;
default:
error:
/* "protocol stall" on error */
retval = -EPIPE;
}
spin_unlock_irqrestore(&musb->lock, flags);
return retval;
}
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