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Serial: p1011: new vendor init options

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Two new options:

CONFIG_PL011_SERIAL_RLCR

Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
have separate receive and transmit line control registers.  Set
this variable to initialize the extra register.

CONFIG_PL011_SERIAL_FLUSH_ON_INIT

On some platforms (e.g. U8500) U-Boot is loaded by a second stage
boot loader that has already initialized the UART.  Define this
variable to flush the UART at init time.
empty fifo on init

Signed-off-by: John Rigby <john.rigby@linaro.org>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
This commit is contained in:
John Rigby 2011-04-19 10:42:39 +00:00 committed by Wolfgang Denk
parent 264eaa0ea9
commit 910f1ae3eb
3 changed files with 42 additions and 2 deletions
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12
README
View File

@ -475,6 +475,18 @@ The following options need to be configured:
define this to a list of base addresses for each (supported)
port. See e.g. include/configs/versatile.h
CONFIG_PL011_SERIAL_RLCR
Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
have separate receive and transmit line control registers. Set
this variable to initialize the extra register.
CONFIG_PL011_SERIAL_FLUSH_ON_INIT
On some platforms (e.g. U8500) U-Boot is loaded by a second stage
boot loader that has already initialized the UART. Define this
variable to flush the UART at init time.
- Console Interface:
Depending on board, define exactly one serial port

28
drivers/serial/serial_pl01x.c
View File

@ -111,6 +111,15 @@ int serial_init (void)
unsigned int divider;
unsigned int remainder;
unsigned int fraction;
unsigned int lcr;
#ifdef CONFIG_PL011_SERIAL_FLUSH_ON_INIT
/* Empty RX fifo if necessary */
if (readl(&regs->pl011_cr) & UART_PL011_CR_UARTEN) {
while (!(readl(&regs->fr) & UART_PL01x_FR_RXFE))
readl(&regs->dr);
}
#endif
/* First, disable everything */
writel(0, &regs->pl011_cr);
@ -131,9 +140,24 @@ int serial_init (void)
writel(fraction, &regs->pl011_fbrd);
/* Set the UART to be 8 bits, 1 stop bit, no parity, fifo enabled */
writel(UART_PL011_LCRH_WLEN_8 | UART_PL011_LCRH_FEN,
&regs->pl011_lcrh);
lcr = UART_PL011_LCRH_WLEN_8 | UART_PL011_LCRH_FEN;
writel(lcr, &regs->pl011_lcrh);
#ifdef CONFIG_PL011_SERIAL_RLCR
{
int i;
/*
* Program receive line control register after waiting
* 10 bus cycles. Delay be writing to readonly register
* 10 times
*/
for (i = 0; i < 10; i++)
writel(lcr, &regs->fr);
writel(lcr, &regs->pl011_rlcr);
}
#endif
/* Finally, enable the UART */
writel(UART_PL011_CR_UARTEN | UART_PL011_CR_TXE | UART_PL011_CR_RXE,
&regs->pl011_cr);

4
drivers/serial/serial_pl01x.h
View File

@ -43,7 +43,11 @@ struct pl01x_regs {
u32 pl010_lcrl; /* 0x10 Line control register, low byte */
u32 pl010_cr; /* 0x14 Control register */
u32 fr; /* 0x18 Flag register (Read only) */
#ifdef CONFIG_PL011_SERIAL_RLCR
u32 pl011_rlcr; /* 0x1c Receive line control register */
#else
u32 reserved;
#endif
u32 ilpr; /* 0x20 IrDA low-power counter register */
u32 pl011_ibrd; /* 0x24 Integer baud rate register */
u32 pl011_fbrd; /* 0x28 Fractional baud rate register */