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 <ag...@denx.de>
---
arch/powerpc/include/asm/mpc52xx.h | 2 +
arch/powerpc/platforms/52xx/mpc52xx_lpbfifo.c | 35 ++++++++++++++++++++++++-
2 files changed, 36 insertions(+), 1 deletions(-)
diff --git a/arch/powerpc/include/asm/mpc52xx.h
b/arch/powerpc/include/asm/mpc52xx.h
index 1f41382..0acc7c7 100644
--- a/arch/powerpc/include/asm/mpc52xx.h
+++ b/arch/powerpc/include/asm/mpc52xx.h
@@ -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);
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_lpbfifo.c
b/arch/powerpc/platforms/52xx/mpc52xx_lpbfifo.c
index d61fb1c..2351f9e 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_lpbfifo.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_lpbfifo.c
@@ -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;
--
1.7.1
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