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/*
* spi-uart debug routings
* Copyright (C) 2008, Feng Tang <feng.tang@intel.com> Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#include "spi-uart.h"
#include "bootstub.h"
#define MRST_SPI_TIMEOUT 0x200000
static int spi_inited = 0;
static volatile struct mrst_spi_reg *pspi = 0;
static void spi_init()
{
u32 ctrlr0;
u32 *clk_reg, clk_cdiv;
switch (*(int *)SPI_TYPE) {
case 0:
pspi = (struct mrst_spi_reg *)MRST_REGBASE_SPI0;
break;
case 1:
pspi = (struct mrst_spi_reg *)MRST_REGBASE_SPI1;
break;
default:
pspi = (struct mrst_spi_reg *)MRST_REGBASE_SPI0;
}
/* disable SPI controller first */
pspi->ssienr = 0x0;
/* set control param, 16 bits, transmit only mode */
ctrlr0 = pspi->ctrlr0;
ctrlr0 &= 0xfcc0;
ctrlr0 |= (0xf | (FRF_SPI << SPI_FRF_OFFSET)
| (TMOD_TO << SPI_TMOD_OFFSET));
pspi->ctrlr0 = ctrlr0;
/* set a default baud rate, 115200 */
/* get SPI controller operating freq info */
clk_reg = (u32 *)MRST_CLK_SPI0_REG;
clk_cdiv = ((*clk_reg) & CLK_SPI_CDIV_MASK) >> CLK_SPI_CDIV_OFFSET;
pspi->baudr = MRST_SPI_CLK_BASE / (clk_cdiv + 1) / 115200;
/* disable all INT for early phase */
pspi->imr &= 0xffffff00;
/* select one slave SPI device */
pspi->ser = 0x2;
/* enable the HW, this should be the last step for HW init */
pspi->ssienr |= 0x1;
spi_inited = 1;
}
/* set the ratio rate, INT */
static void max3110_write_config(void)
{
u16 config;
/* 115200, TM not set, no parity, 8bit word */
config = 0xc001;
pspi->dr[0] = config;
}
/* transfer char to a eligibal word and send to max3110 */
static void max3110_write_data(char c)
{
u16 data;
data = 0x8000 | c;
pspi->dr[0] = data;
}
/* slave select should be called in the read/write function */
static int spi_max3110_putc(char c)
{
unsigned int timeout;
u32 sr;
timeout = MRST_SPI_TIMEOUT;
/* early putc need make sure the TX FIFO is not full*/
while (timeout--) {
sr = pspi->sr;
if (!(sr & SR_TF_NOT_FULL))
continue;
else
break;
}
if (timeout == 0xffffffff)
return -1;
max3110_write_data(c);
return 0;
}
void bs_spi_printk(const char *str)
{
if (!spi_inited) {
spi_init();
max3110_write_config();
}
if (!str)
return;
while (*str) {
if (*str == '\n')
spi_max3110_putc('\r');
spi_max3110_putc(*str++);
}
}
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