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USB: s3c-hsotg: Ensure FIFOs are fully flushed after layout

According to the design guide, if the FIFO layout is changed, then the
FIFOs must be flushed to ensure all FIFO pointers are correct.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Ben Dooks 2010-05-25 05:36:52 +01:00 committed by Greg Kroah-Hartman
parent 2e0e0777ec
commit 1703a6d3c3
1 changed files with 26 additions and 0 deletions

View File

@ -300,6 +300,7 @@ static void s3c_hsotg_init_fifo(struct s3c_hsotg *hsotg)
unsigned int ep;
unsigned int addr;
unsigned int size;
int timeout;
u32 val;
/* the ryu 2.6.24 release ahs
@ -335,6 +336,31 @@ static void s3c_hsotg_init_fifo(struct s3c_hsotg *hsotg)
writel(val, hsotg->regs + S3C_DPTXFSIZn(ep));
}
/* according to p428 of the design guide, we need to ensure that
* all fifos are flushed before continuing */
writel(S3C_GRSTCTL_TxFNum(0x10) | S3C_GRSTCTL_TxFFlsh |
S3C_GRSTCTL_RxFFlsh, hsotg->regs + S3C_GRSTCTL);
/* wait until the fifos are both flushed */
timeout = 100;
while (1) {
val = readl(hsotg->regs + S3C_GRSTCTL);
if ((val & (S3C_GRSTCTL_TxFFlsh | S3C_GRSTCTL_RxFFlsh)) == 0)
break;
if (--timeout == 0) {
dev_err(hsotg->dev,
"%s: timeout flushing fifos (GRSTCTL=%08x)\n",
__func__, val);
}
udelay(1);
}
dev_dbg(hsotg->dev, "FIFOs reset, timeout at %d\n", timeout);
}
/**