diff options
Diffstat (limited to 'drivers/serial/serial_pl011.c')
| -rw-r--r-- | drivers/serial/serial_pl011.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/drivers/serial/serial_pl011.c b/drivers/serial/serial_pl011.c new file mode 100644 index 0000000..4d35fe5 --- /dev/null +++ b/drivers/serial/serial_pl011.c @@ -0,0 +1,161 @@ +/* + * (C) Copyright 2000 + * Rob Taylor, Flying Pig Systems. robt@flyingpig.com. + * + * (C) Copyright 2004 + * ARM Ltd. + * Philippe Robin, <philippe.robin@arm.com> + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +/* Simple U-Boot driver for the PrimeCell PL011 UARTs on the IntegratorCP */ +/* Should be fairly simple to make it work with the PL010 as well */ + +#include <common.h> + +#ifdef CFG_PL011_SERIAL + +#include "serial_pl011.h" + +#define IO_WRITE(addr, val) (*(volatile unsigned int *)(addr) = (val)) +#define IO_READ(addr) (*(volatile unsigned int *)(addr)) + +/* + * IntegratorCP has two UARTs, use the first one, at 38400-8-N-1 + * Versatile PB has four UARTs. + */ + +#define CONSOLE_PORT CONFIG_CONS_INDEX +#define baudRate CONFIG_BAUDRATE +static volatile unsigned char *const port[] = CONFIG_PL01x_PORTS; +#define NUM_PORTS (sizeof(port)/sizeof(port[0])) + +static void pl011_putc (int portnum, char c); +static int pl011_getc (int portnum); +static int pl011_tstc (int portnum); + + +int serial_init (void) +{ + unsigned int temp; + unsigned int divider; + unsigned int remainder; + unsigned int fraction; + + /* + ** First, disable everything. + */ + IO_WRITE (port[CONSOLE_PORT] + UART_PL011_CR, 0x0); + + /* + ** Set baud rate + ** + ** IBRD = UART_CLK / (16 * BAUD_RATE) + ** FBRD = ROUND((64 * MOD(UART_CLK,(16 * BAUD_RATE))) / (16 * BAUD_RATE)) + */ + temp = 16 * baudRate; + divider = CONFIG_PL011_CLOCK / temp; + remainder = CONFIG_PL011_CLOCK % temp; + temp = (8 * remainder) / baudRate; + fraction = (temp >> 1) + (temp & 1); + + IO_WRITE (port[CONSOLE_PORT] + UART_PL011_IBRD, divider); + IO_WRITE (port[CONSOLE_PORT] + UART_PL011_FBRD, fraction); + + /* + ** Set the UART to be 8 bits, 1 stop bit, no parity, fifo enabled. + */ + IO_WRITE (port[CONSOLE_PORT] + UART_PL011_LCRH, + (UART_PL011_LCRH_WLEN_8 | UART_PL011_LCRH_FEN)); + + /* + ** Finally, enable the UART + */ + IO_WRITE (port[CONSOLE_PORT] + UART_PL011_CR, + (UART_PL011_CR_UARTEN | UART_PL011_CR_TXE | + UART_PL011_CR_RXE)); + + return 0; +} + +void serial_putc (const char c) +{ + if (c == '\n') + pl011_putc (CONSOLE_PORT, '\r'); + + pl011_putc (CONSOLE_PORT, c); +} + +void serial_puts (const char *s) +{ + while (*s) { + serial_putc (*s++); + } +} + +int serial_getc (void) +{ + return pl011_getc (CONSOLE_PORT); +} + +int serial_tstc (void) +{ + return pl011_tstc (CONSOLE_PORT); +} + +void serial_setbrg (void) +{ +} + +static void pl011_putc (int portnum, char c) +{ + /* Wait until there is space in the FIFO */ + while (IO_READ (port[portnum] + UART_PL01x_FR) & UART_PL01x_FR_TXFF); + + /* Send the character */ + IO_WRITE (port[portnum] + UART_PL01x_DR, c); +} + +static int pl011_getc (int portnum) +{ + unsigned int data; + + /* Wait until there is data in the FIFO */ + while (IO_READ (port[portnum] + UART_PL01x_FR) & UART_PL01x_FR_RXFE); + + data = IO_READ (port[portnum] + UART_PL01x_DR); + + /* Check for an error flag */ + if (data & 0xFFFFFF00) { + /* Clear the error */ + IO_WRITE (port[portnum] + UART_PL01x_ECR, 0xFFFFFFFF); + return -1; + } + + return (int) data; +} + +static int pl011_tstc (int portnum) +{ + return !(IO_READ (port[portnum] + UART_PL01x_FR) & + UART_PL01x_FR_RXFE); +} + +#endif |