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powerpc/mpc52xx_lpbfifo: optionally defer fifo transfer start 

Currently fifo transfer is started when submitting a transfer
request. Add posibility to defer the fifo transfer and start it
later by calling additional function. This change is backward
compatible, the behaviour of mpc52xx_lpbfifo_submit() is the same
for previous driver users, so there is no need to adapt them.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
This commit is contained in:
Anatolij Gustschin 2012-08-29 21:33:28 +00:00
parent 00e4b1975b
commit 9d9fd8871b
2 changed files with 36 additions and 1 deletions
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2
arch/powerpc/include/asm/mpc52xx.h
View File

@ -307,6 +307,7 @@ struct mpc52xx_lpbfifo_request {
size_t size;
size_t pos; /* current position of transfer */
int flags;
int defer_xfer_start;
/* What to do when finished */
void (*callback)(struct mpc52xx_lpbfifo_request *);
@ -323,6 +324,7 @@ struct mpc52xx_lpbfifo_request {
extern int mpc52xx_lpbfifo_submit(struct mpc52xx_lpbfifo_request *req);
extern void mpc52xx_lpbfifo_abort(struct mpc52xx_lpbfifo_request *req);
extern void mpc52xx_lpbfifo_poll(void);
extern int mpc52xx_lpbfifo_start_xfer(struct mpc52xx_lpbfifo_request *req);
/* mpc52xx_pic.c */
extern void mpc52xx_init_irq(void);

35
arch/powerpc/platforms/52xx/mpc52xx_lpbfifo.c
View File

@ -170,7 +170,8 @@ static void mpc52xx_lpbfifo_kick(struct mpc52xx_lpbfifo_request *req)
out_be32(lpbfifo.regs + LPBFIFO_REG_CONTROL, bit_fields);
/* Kick it off */
out_8(lpbfifo.regs + LPBFIFO_REG_PACKET_SIZE, 0x01);
if (!lpbfifo.req->defer_xfer_start)
out_8(lpbfifo.regs + LPBFIFO_REG_PACKET_SIZE, 0x01);
if (dma)
bcom_enable(lpbfifo.bcom_cur_task);
}
@ -421,6 +422,38 @@ int mpc52xx_lpbfifo_submit(struct mpc52xx_lpbfifo_request *req)
}
EXPORT_SYMBOL(mpc52xx_lpbfifo_submit);
int mpc52xx_lpbfifo_start_xfer(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 and a transfer was
* started on submit, then this transfer is in progress
*/
if (lpbfifo.req && !lpbfifo.req->defer_xfer_start) {
spin_unlock_irqrestore(&lpbfifo.lock, flags);
return -EBUSY;
}
/*
* If the req was previously submitted but not
* started, start it now
*/
if (lpbfifo.req && lpbfifo.req == req &&
lpbfifo.req->defer_xfer_start) {
out_8(lpbfifo.regs + LPBFIFO_REG_PACKET_SIZE, 0x01);
}
spin_unlock_irqrestore(&lpbfifo.lock, flags);
return 0;
}
EXPORT_SYMBOL(mpc52xx_lpbfifo_start_xfer);
void mpc52xx_lpbfifo_abort(struct mpc52xx_lpbfifo_request *req)
{
unsigned long flags;