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Fix BRD calculation; Handle edge interrupts

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git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@1804 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2009-05-19 22:51:33 +00:00
parent 6c14840f2e
commit d6966b2892
1 changed files with 25 additions and 5 deletions
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30
arch/arm/src/lm3s/lm3s_serial.c
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@ -398,9 +398,9 @@ static int up_setup(struct uart_dev_s *dev)
* write to the UARTLCRH register for the changes to take effect. ..."
*/
den = priv->baud << 16;
den = priv->baud << 4;
brdi = SYSCLK_FREQUENCY / den;
remainder = priv->baud - den * brdi;
remainder = SYSCLK_FREQUENCY - den * brdi;
divfrac = ((remainder << 6) + (den >> 1)) / den;
up_serialout(priv, LM3S_UART_IBRD_OFFSET, brdi);
@ -465,7 +465,7 @@ static int up_setup(struct uart_dev_s *dev)
/* Enable the FIFOs */
#ifndef CONFIG_SUPPRESS_UART_CONFIG
#ifdef CONFIG_SUPPRESS_UART_CONFIG
lcrh = up_serialin(priv, LM3S_UART_LCRH_OFFSET);
#endif
lcrh |= UART_LCRH_FEN;
@ -473,7 +473,7 @@ static int up_setup(struct uart_dev_s *dev)
/* Enable Rx, Tx, and the UART */
#ifndef CONFIG_SUPPRESS_UART_CONFIG
#ifdef CONFIG_SUPPRESS_UART_CONFIG
ctl = up_serialin(priv, LM3S_UART_CTL_OFFSET);
#endif
ctl |= (UART_CTL_UARTEN|UART_CTL_TXE|UART_CTL_RXE);
@ -760,18 +760,38 @@ static void up_send(struct uart_dev_s *dev, int ch)
static void up_txint(struct uart_dev_s *dev, boolean enable)
{
struct up_dev_s *priv = (struct up_dev_s*)dev->priv;
irqstate_t flags;
flags = irqsave();
if (enable)
{
/* Set to receive an interrupt when the TX fifo is half emptied */
#ifndef CONFIG_SUPPRESS_SERIAL_INTS
priv->im |= UART_IM_TXIM;
up_serialout(priv, LM3S_UART_IM_OFFSET, priv->im);
/* The serial driver wants an interrupt here, but will not get get
* one unless we "prime the pump." I believe that this is because
* behave like a level interrupt and the LM3S interrupts behave
* (at least by default) like edge interrupts.
*
* In any event, faking a TX interrupt here solves the problem;
* Call uart_xmitchars() just as would have been done if we recieved
* the TX interrupt.
*/
uart_xmitchars(dev);
#endif
}
else
{
/* Disable the TX interrupt */
priv->im &= ~UART_IM_TXIM;
up_serialout(priv, LM3S_UART_IM_OFFSET, priv->im);
}
up_serialout(priv, LM3S_UART_IM_OFFSET, priv->im);
irqrestore(flags);
}
/****************************************************************************