/**
* mpc52xx_lpbfifo_submit - Submit an LPB FIFO transfer request.
* @req: Pointer to request structure
*/
int mpc52xx_lpbfifo_submit(struct mpc52xx_lpbfifo_request *req)
{
unsigned long flags;
if (!lpbfifo.regs)
return -ENODEV;
spin_lock_irqsave(&lpbfifo.lock, flags);
/* If the req pointer is already set, then a transfer is in progress */
if (lpbfifo.req) {
spin_unlock_irqrestore(&lpbfifo.lock, flags);
return -EBUSY;
}
/* Setup the transfer */
lpbfifo.req = req;
req->irq_count = 0;
req->irq_ticks = 0;
req->buffer_not_done_cnt = 0;
req->pos = 0;
mpc52xx_lpbfifo_kick(req);
spin_unlock_irqrestore(&lpbfifo.lock, flags);
return 0;
}
int mpc52xx_lpbfifo_submit(struct mpc52xx_lpbfifo_request *req)
{
unsigned long flags;
if (!lpbfifo.regs)
return -ENODEV;
spin_lock_irqsave(&lpbfifo.lock, flags);
/* */
if (lpbfifo.req) {
spin_unlock_irqrestore(&lpbfifo.lock, flags);
return -EBUSY;
}
/* */
lpbfifo.req = req;
req->irq_count = 0;
req->irq_ticks = 0;
req->buffer_not_done_cnt = 0;
req->pos = 0;
mpc52xx_lpbfifo_kick(req);
spin_unlock_irqrestore(&lpbfifo.lock, flags);
return 0;
}
/**
* mpc52xx_lpbfifo_irq - IRQ handler for LPB FIFO
*
* On transmit, the dma completion irq triggers before the fifo completion
* triggers. Handle the dma completion here instead of the LPB FIFO Bestcomm
* task completion irq because everything is not really done until the LPB FIFO
* completion irq triggers.
*
* In other words:
* For DMA, on receive, the "Fat Lady" is the bestcom completion irq. on
* transmit, the fifo completion irq is the "Fat Lady". The opera (or in this
* case the DMA/FIFO operation) is not finished until the "Fat Lady" sings.
*
* Reasons for entering this routine:
* 1) PIO mode rx and tx completion irq
* 2) DMA interrupt mode tx completion irq
* 3) DMA polled mode tx
*
* Exit conditions:
* 1) Transfer aborted
* 2) FIFO complete without DMA; more data to do
* 3) FIFO complete without DMA; all data transferred
* 4) FIFO complete using DMA
*
* Condition 1 can occur regardless of whether or not DMA is used.
* It requires executing the callback to report the error and exiting
* immediately.
*
* Condition 2 requires programming the FIFO with the next block of data
*
* Condition 3 requires executing the callback to report completion
*
* Condition 4 means the same as 3, except that we also retrieve the bcom
* buffer so DMA doesn't get clogged up.
*
* To make things trickier, the spinlock must be dropped before
* executing the callback, otherwise we could end up with a deadlock
* or nested spinlock condition. The out path is non-trivial, so
* extra fiddling is done to make sure all paths lead to the same
* outbound code.
*/
static irqreturn_t mpc52xx_lpbfifo_irq(int irq, void *dev_id)
{
struct mpc52xx_lpbfifo_request *req;
u32 status = in_8(lpbfifo.regs + LPBFIFO_REG_BYTES_DONE_STATUS);
void __iomem *reg;
u32 *data;
int count, i;
int do_callback = 0;
u32 ts;
unsigned long flags;
int dma, write, poll_dma;
spin_lock_irqsave(&lpbfifo.lock, flags);
ts = get_tbl();
req = lpbfifo.req;
if (!req) {
spin_unlock_irqrestore(&lpbfifo.lock, flags);
pr_err("bogus LPBFIFO IRQ\n");
return IRQ_HANDLED;
}
dma = !(req->flags & MPC52XX_LPBFIFO_FLAG_NO_DMA);
write = req->flags & MPC52XX_LPBFIFO_FLAG_WRITE;
poll_dma = req->flags & MPC52XX_LPBFIFO_FLAG_POLL_DMA;
if (dma && !write) {
spin_unlock_irqrestore(&lpbfifo.lock, flags);
pr_err("bogus LPBFIFO IRQ (dma and not writting)\n");
return IRQ_HANDLED;
}
if ((status & 0x01) == 0) {
goto out;
}
/* check abort bit */
if (status & 0x10) {
out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x01010000);
do_callback = 1;
goto out;
}
/* Read result from hardware */
count = in_be32(lpbfifo.regs + LPBFIFO_REG_BYTES_DONE_STATUS);
count &= 0x00ffffff;
if (!dma && !write) {
/* copy the data out of the FIFO */
reg = lpbfifo.regs + LPBFIFO_REG_FIFO_DATA;
data = req->data + req->pos;
for (i = 0; i < count; i += 4)
*data++ = in_be32(reg);
}
/* Update transfer position and count */
req->pos += count;
/* Decide what to do next */
if (req->size - req->pos)
mpc52xx_lpbfifo_kick(req); /* more work to do */
else
do_callback = 1;
out:
/* Clear the IRQ */
out_8(lpbfifo.regs + LPBFIFO_REG_BYTES_DONE_STATUS, 0x01);
if (dma && (status & 0x11)) {
/*
* Count the DMA as complete only when the FIFO completion
* status or abort bits are set.
*
* (status & 0x01) should always be the case except sometimes
* when using polled DMA.
*
* (status & 0x10) {transfer aborted}: This case needs more
* testing.
*/
bcom_retrieve_buffer(lpbfifo.bcom_cur_task, &status, NULL);
}
req->last_byte = ((u8 *)req->data)[req->size - 1];
/* When the do_callback flag is set; it means the transfer is finished
* so set the FIFO as idle */
if (do_callback)
lpbfifo.req = NULL;
if (irq != 0) /* don't increment on polled case */
req->irq_count++;
req->irq_ticks += get_tbl() - ts;
spin_unlock_irqrestore(&lpbfifo.lock, flags);
/* Spinlock is released; it is now safe to call the callback */
if (do_callback && req->callback)
req->callback(req);
return IRQ_HANDLED;
}
static irqreturn_t mpc52xx_lpbfifo_irq(int irq, void *dev_id)
{
struct mpc52xx_lpbfifo_request *req;
u32 status = in_8(lpbfifo.regs + LPBFIFO_REG_BYTES_DONE_STATUS);
void __iomem *reg;
u32 *data;
int count, i;
int do_callback = 0;
u32 ts;
unsigned long flags;
int dma, write, poll_dma;
spin_lock_irqsave(&lpbfifo.lock, flags);
ts = get_tbl();
req = lpbfifo.req;
if (!req) {
spin_unlock_irqrestore(&lpbfifo.lock, flags);
pr_err("bogus LPBFIFO IRQ\n");
return IRQ_HANDLED;
}
dma = !(req->flags & MPC52XX_LPBFIFO_FLAG_NO_DMA);
write = req->flags & MPC52XX_LPBFIFO_FLAG_WRITE;
poll_dma = req->flags & MPC52XX_LPBFIFO_FLAG_POLL_DMA;
if (dma && !write) {
spin_unlock_irqrestore(&lpbfifo.lock, flags);
pr_err("bogus LPBFIFO IRQ (dma and not writting)\n");
return IRQ_HANDLED;
}
if ((status & 0x01) == 0) {
goto out;
}
/* */
if (status & 0x10) {
out_be32(lpbfifo.regs + LPBFIFO_REG_ENABLE, 0x01010000);
do_callback = 1;
goto out;
}
/* */
count = in_be32(lpbfifo.regs + LPBFIFO_REG_BYTES_DONE_STATUS);
count &= 0x00ffffff;
if (!dma && !write) {
/* */
reg = lpbfifo.regs + LPBFIFO_REG_FIFO_DATA;
data = req->data + req->pos;
for (i = 0; i < count; i += 4)
*data++ = in_be32(reg);
}
/* */
req->pos += count;
/* */
if (req->size - req->pos)
mpc52xx_lpbfifo_kick(req); /* */
else
do_callback = 1;
out:
/* */
out_8(lpbfifo.regs + LPBFIFO_REG_BYTES_DONE_STATUS, 0x01);
if (dma && (status & 0x11)) {
/*
*/
bcom_retrieve_buffer(lpbfifo.bcom_cur_task, &status, NULL);
}
req->last_byte = ((u8 *)req->data)[req->size - 1];
/*
*/
if (do_callback)
lpbfifo.req = NULL;
if (irq != 0) /* */
req->irq_count++;
req->irq_ticks += get_tbl() - ts;
spin_unlock_irqrestore(&lpbfifo.lock, flags);
/* */
if (do_callback && req->callback)
req->callback(req);
return IRQ_HANDLED;
}