u-boot/drivers/serial/lpc32xx_hsuart.c
Marek Vasut e503f90a57 serial: arm: Implement CONFIG_SERIAL_MULTI into lpc32xx serial driver
Implement support for CONFIG_SERIAL_MULTI into lpc32xx serial driver.
This driver was so far only usable directly, but this patch also adds
support for the multi method. This allows using more than one serial
driver alongside the lpc32xx driver. Also, add a weak implementation
of default_serial_console() returning this driver.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Marek Vasut <marek.vasut@gmail.com>
Cc: Tom Rini <trini@ti.com>
Cc: Vladimir Zapolskiy <vz@mleia.com>
2012-10-15 11:53:54 -07:00

137 lines
2.9 KiB
C

/*
* Copyright (C) 2011 Vladimir Zapolskiy <vz@mleia.com>
*
* 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., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
#include <common.h>
#include <asm/arch/cpu.h>
#include <asm/arch/clk.h>
#include <asm/arch/uart.h>
#include <asm/io.h>
#include <serial.h>
#include <linux/compiler.h>
DECLARE_GLOBAL_DATA_PTR;
static struct hsuart_regs *hsuart = (struct hsuart_regs *)HS_UART_BASE;
static void lpc32xx_serial_setbrg(void)
{
u32 div;
/* UART rate = PERIPH_CLK / ((HSU_RATE + 1) x 14) */
div = (get_serial_clock() / 14 + gd->baudrate / 2) / gd->baudrate - 1;
if (div > 255)
div = 255;
writel(div, &hsuart->rate);
}
static int lpc32xx_serial_getc(void)
{
while (!(readl(&hsuart->level) & HSUART_LEVEL_RX))
/* NOP */;
return readl(&hsuart->rx) & HSUART_RX_DATA;
}
static void lpc32xx_serial_putc(const char c)
{
writel(c, &hsuart->tx);
/* Wait for character to be sent */
while (readl(&hsuart->level) & HSUART_LEVEL_TX)
/* NOP */;
}
static int lpc32xx_serial_tstc(void)
{
if (readl(&hsuart->level) & HSUART_LEVEL_RX)
return 1;
return 0;
}
static int lpc32xx_serial_init(void)
{
lpc32xx_serial_setbrg();
/* Disable hardware RTS and CTS flow control, set up RX and TX FIFO */
writel(HSUART_CTRL_TMO_16 | HSUART_CTRL_HSU_OFFSET(20) |
HSUART_CTRL_HSU_RX_TRIG_32 | HSUART_CTRL_HSU_TX_TRIG_0,
&hsuart->ctrl);
return 0;
}
static void lpc32xx_serial_puts(const char *s)
{
while (*s)
serial_putc(*s++);
}
#ifdef CONFIG_SERIAL_MULTI
static struct serial_device lpc32xx_serial_drv = {
.name = "lpc32xx_serial",
.start = lpc32xx_serial_init,
.stop = NULL,
.setbrg = lpc32xx_serial_setbrg,
.putc = lpc32xx_serial_putc,
.puts = lpc32xx_serial_puts,
.getc = lpc32xx_serial_getc,
.tstc = lpc32xx_serial_tstc,
};
void lpc32xx_serial_initialize(void)
{
serial_register(&lpc32xx_serial_drv);
}
__weak struct serial_device *default_serial_console(void)
{
return &lpc32xx_serial_drv;
}
#else
int serial_init(void)
{
return lpc32xx_serial_init();
}
void serial_setbrg(void)
{
lpc32xx_serial_setbrg();
}
void serial_putc(const char c)
{
lpc32xx_serial_putc(c);
}
void serial_puts(const char *s)
{
lpc32xx_serial_puts(s);
}
int serial_getc(void)
{
return lpc32xx_serial_getc();
}
int serial_tstc(void)
{
return lpc32xx_serial_tstc();
}
#endif