diff options
Diffstat (limited to 'arch/sparc/cpu/leon3/serial.c')
| -rw-r--r-- | arch/sparc/cpu/leon3/serial.c | 139 | 
1 files changed, 139 insertions, 0 deletions
| diff --git a/arch/sparc/cpu/leon3/serial.c b/arch/sparc/cpu/leon3/serial.c new file mode 100644 index 000000000..4b2fcb866 --- /dev/null +++ b/arch/sparc/cpu/leon3/serial.c @@ -0,0 +1,139 @@ +/* GRLIB APBUART Serial controller driver + * + * (C) Copyright 2007 + * Daniel Hellstrom, Gaisler Research, daniel@gaisler.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 + * + */ + +#include <common.h> +#include <asm/processor.h> +#include <asm/leon.h> +#include <ambapp.h> + +DECLARE_GLOBAL_DATA_PTR; + +/* Force cache miss each time a serial controller reg is read */ +#define CACHE_BYPASS 1 + +#ifdef CACHE_BYPASS +#define READ_BYTE(var)  SPARC_NOCACHE_READ_BYTE((unsigned int)&(var)) +#define READ_HWORD(var) SPARC_NOCACHE_READ_HWORD((unsigned int)&(var)) +#define READ_WORD(var)  SPARC_NOCACHE_READ((unsigned int)&(var)) +#define READ_DWORD(var) SPARC_NOCACHE_READ_DWORD((unsigned int)&(var)) +#endif + +ambapp_dev_apbuart *leon3_apbuart = NULL; + +int serial_init(void) +{ +	ambapp_apbdev apbdev; +	unsigned int tmp; + +	/* find UART */ +	if (ambapp_apb_first(VENDOR_GAISLER, GAISLER_APBUART, &apbdev) == 1) { + +		leon3_apbuart = (ambapp_dev_apbuart *) apbdev.address; + +		/* found apbuart, let's init... +		 * +		 * Set scaler / baud rate +		 * +		 * Receiver & transmitter enable +		 */ +		leon3_apbuart->scaler = CONFIG_SYS_GRLIB_APBUART_SCALER; + +		/* Let bit 11 be unchanged (debug bit for GRMON) */ +		tmp = READ_WORD(leon3_apbuart->ctrl); + +		leon3_apbuart->ctrl = ((tmp & LEON_REG_UART_CTRL_DBG) | +				       LEON_REG_UART_CTRL_RE | +				       LEON_REG_UART_CTRL_TE); + +		return 0; +	} +	return -1;		/* didn't find hardware */ +} + +void serial_putc(const char c) +{ +	if (c == '\n') +		serial_putc_raw('\r'); + +	serial_putc_raw(c); +} + +void serial_putc_raw(const char c) +{ +	if (!leon3_apbuart) +		return; + +	/* Wait for last character to go. */ +	while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_THE)) ; + +	/* Send data */ +	leon3_apbuart->data = c; + +#ifdef LEON_DEBUG +	/* Wait for data to be sent */ +	while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_TSE)) ; +#endif +} + +void serial_puts(const char *s) +{ +	while (*s) { +		serial_putc(*s++); +	} +} + +int serial_getc(void) +{ +	if (!leon3_apbuart) +		return 0; + +	/* Wait for a character to arrive. */ +	while (!(READ_WORD(leon3_apbuart->status) & LEON_REG_UART_STATUS_DR)) ; + +	/* read data */ +	return READ_WORD(leon3_apbuart->data); +} + +int serial_tstc(void) +{ +	if (leon3_apbuart) +		return (READ_WORD(leon3_apbuart->status) & +			LEON_REG_UART_STATUS_DR); +	return 0; +} + +/* set baud rate for uart */ +void serial_setbrg(void) +{ +	/* update baud rate settings, read it from gd->baudrate */ +	unsigned int scaler; +	if (leon3_apbuart && (gd->baudrate > 0)) { +		scaler = +		    (((CONFIG_SYS_CLK_FREQ * 10) / (gd->baudrate * 8)) - +		     5) / 10; +		leon3_apbuart->scaler = scaler; +	} +	return; +} |