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openwrt-xburst/package/uboot-ar71xx/files/cpu/mips/ar71xx_serial.c

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/*
* (C) Copyright 2010
* Michael Kurz <michi.kurz@googlemail.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 <asm/addrspace.h>
#include <asm/types.h>
#include <config.h>
#include <asm/ar71xx.h>
#define REG_SIZE 4
/* === END OF CONFIG === */
/* register offset */
#define OFS_RCV_BUFFER (0*REG_SIZE)
#define OFS_TRANS_HOLD (0*REG_SIZE)
#define OFS_SEND_BUFFER (0*REG_SIZE)
#define OFS_INTR_ENABLE (1*REG_SIZE)
#define OFS_INTR_ID (2*REG_SIZE)
#define OFS_DATA_FORMAT (3*REG_SIZE)
#define OFS_LINE_CONTROL (3*REG_SIZE)
#define OFS_MODEM_CONTROL (4*REG_SIZE)
#define OFS_RS232_OUTPUT (4*REG_SIZE)
#define OFS_LINE_STATUS (5*REG_SIZE)
#define OFS_MODEM_STATUS (6*REG_SIZE)
#define OFS_RS232_INPUT (6*REG_SIZE)
#define OFS_SCRATCH_PAD (7*REG_SIZE)
#define OFS_DIVISOR_LSB (0*REG_SIZE)
#define OFS_DIVISOR_MSB (1*REG_SIZE)
#define UART16550_READ(y) readl(KSEG1ADDR(AR71XX_UART_BASE+y))
#define UART16550_WRITE(x, z) writel(z, KSEG1ADDR((AR71XX_UART_BASE+x)))
void
ar71xx_sys_frequency(u32 *cpu_freq, u32 *ddr_freq, u32 *ahb_freq)
{
#ifndef CONFIG_AR91XX
u32 pll, pll_div, cpu_div, ahb_div, ddr_div, freq;
pll = readl(KSEG1ADDR(AR71XX_PLL_REG_CPU_CONFIG + AR71XX_PLL_BASE));
pll_div =
((pll & AR71XX_PLL_DIV_MASK) >> AR71XX_PLL_DIV_SHIFT) + 1;
cpu_div =
((pll & AR71XX_CPU_DIV_MASK) >> AR71XX_CPU_DIV_SHIFT) + 1;
ddr_div =
((pll & AR71XX_DDR_DIV_MASK) >> AR71XX_DDR_DIV_SHIFT) + 1;
ahb_div =
(((pll & AR71XX_AHB_DIV_MASK) >> AR71XX_AHB_DIV_SHIFT) + 1)*2;
freq = pll_div * 40000000;
if (cpu_freq)
*cpu_freq = freq/cpu_div;
if (ddr_freq)
*ddr_freq = freq/ddr_div;
if (ahb_freq)
*ahb_freq = (freq/cpu_div)/ahb_div;
#else
u32 pll, pll_div, ahb_div, ddr_div, freq;
pll = readl(KSEG1ADDR(AR91XX_PLL_REG_CPU_CONFIG + AR71XX_PLL_BASE));
pll_div =
((pll & AR91XX_PLL_DIV_MASK) >> AR91XX_PLL_DIV_SHIFT);
ddr_div =
((pll & AR91XX_DDR_DIV_MASK) >> AR91XX_DDR_DIV_SHIFT) + 1;
ahb_div =
(((pll & AR91XX_AHB_DIV_MASK) >> AR91XX_AHB_DIV_SHIFT) + 1)*2;
freq = pll_div * 5000000;
if (cpu_freq)
*cpu_freq = freq;
if (ddr_freq)
*ddr_freq = freq/ddr_div;
if (ahb_freq)
*ahb_freq = freq/ahb_div;
#endif
}
int serial_init(void)
{
u32 div;
u32 ahb_freq = 100000000;
ar71xx_sys_frequency (0, 0, &ahb_freq);
div = ahb_freq/(16 * CONFIG_BAUDRATE);
// enable uart pins
#ifndef CONFIG_AR91XX
writel(AR71XX_GPIO_FUNC_UART_EN, KSEG1ADDR(AR71XX_GPIO_BASE + GPIO_REG_FUNC));
#else
writel(AR91XX_GPIO_FUNC_UART_EN, KSEG1ADDR(AR71XX_GPIO_BASE + GPIO_REG_FUNC));
#endif
/* set DIAB bit */
UART16550_WRITE(OFS_LINE_CONTROL, 0x80);
/* set divisor */
UART16550_WRITE(OFS_DIVISOR_LSB, (div & 0xff));
UART16550_WRITE(OFS_DIVISOR_MSB, ((div >> 8) & 0xff));
/* clear DIAB bit*/
UART16550_WRITE(OFS_LINE_CONTROL, 0x00);
/* set data format */
UART16550_WRITE(OFS_DATA_FORMAT, 0x3);
UART16550_WRITE(OFS_INTR_ENABLE, 0);
return 0;
}
int serial_tstc (void)
{
return(UART16550_READ(OFS_LINE_STATUS) & 0x1);
}
int serial_getc(void)
{
while(!serial_tstc());
return UART16550_READ(OFS_RCV_BUFFER);
}
void serial_putc(const char byte)
{
if (byte == '\n') serial_putc ('\r');
while (((UART16550_READ(OFS_LINE_STATUS)) & 0x20) == 0x0);
UART16550_WRITE(OFS_SEND_BUFFER, byte);
}
void serial_setbrg (void)
{
}
void serial_puts (const char *s)
{
while (*s)
{
serial_putc (*s++);
}
}