u-boot/drivers/serial/serial_max3100.c
Marek Vasut 7cd851a50b serial: Implement CONFIG_SERIAL_MULTI into max3100 serial driver
Implement support for CONFIG_SERIAL_MULTI into max3100 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 max3100 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>
2012-10-15 11:53:56 -07:00

342 lines
7.8 KiB
C

/*
* (C) Copyright 2003
*
* Pantelis Antoniou <panto@intracom.gr>
* Intracom S.A.
*
* 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 <watchdog.h>
#include <serial.h>
#include <linux/compiler.h>
DECLARE_GLOBAL_DATA_PTR;
/**************************************************************/
/* convienient macros */
#define MAX3100_SPI_RXD() (MAX3100_SPI_RXD_PORT & MAX3100_SPI_RXD_BIT)
#define MAX3100_SPI_TXD(x) \
do { \
if (x) \
MAX3100_SPI_TXD_PORT |= MAX3100_SPI_TXD_BIT; \
else \
MAX3100_SPI_TXD_PORT &= ~MAX3100_SPI_TXD_BIT; \
} while(0)
#define MAX3100_SPI_CLK(x) \
do { \
if (x) \
MAX3100_SPI_CLK_PORT |= MAX3100_SPI_CLK_BIT; \
else \
MAX3100_SPI_CLK_PORT &= ~MAX3100_SPI_CLK_BIT; \
} while(0)
#define MAX3100_SPI_CLK_TOGGLE() (MAX3100_SPI_CLK_PORT ^= MAX3100_SPI_CLK_BIT)
#define MAX3100_CS(x) \
do { \
if (x) \
MAX3100_CS_PORT |= MAX3100_CS_BIT; \
else \
MAX3100_CS_PORT &= ~MAX3100_CS_BIT; \
} while(0)
/**************************************************************/
/* MAX3100 definitions */
#define MAX3100_WC (3 << 14) /* write configuration */
#define MAX3100_RC (1 << 14) /* read configuration */
#define MAX3100_WD (2 << 14) /* write data */
#define MAX3100_RD (0 << 14) /* read data */
/* configuration register bits */
#define MAX3100_FEN (1 << 13) /* FIFO enable */
#define MAX3100_SHDN (1 << 12) /* shutdown bit */
#define MAX3100_TM (1 << 11) /* T bit irq mask */
#define MAX3100_RM (1 << 10) /* R bit irq mask */
#define MAX3100_PM (1 << 9) /* P bit irq mask */
#define MAX3100_RAM (1 << 8) /* mask for RA/FE bit */
#define MAX3100_IR (1 << 7) /* IRDA timing mode */
#define MAX3100_ST (1 << 6) /* transmit stop bit */
#define MAX3100_PE (1 << 5) /* parity enable bit */
#define MAX3100_L (1 << 4) /* Length bit */
#define MAX3100_B_MASK (0x000F) /* baud rate bits mask */
#define MAX3100_B(x) ((x) & 0x000F) /* baud rate select bits */
/* data register bits (write) */
#define MAX3100_TE (1 << 10) /* transmit enable bit (active low) */
#define MAX3100_RTS (1 << 9) /* request-to-send bit (inverted ~RTS pin) */
/* data register bits (read) */
#define MAX3100_RA (1 << 10) /* receiver activity when in shutdown mode */
#define MAX3100_FE (1 << 10) /* framing error when in normal mode */
#define MAX3100_CTS (1 << 9) /* clear-to-send bit (inverted ~CTS pin) */
/* data register bits (both directions) */
#define MAX3100_R (1 << 15) /* receive bit */
#define MAX3100_T (1 << 14) /* transmit bit */
#define MAX3100_P (1 << 8) /* parity bit */
#define MAX3100_D_MASK 0x00FF /* data bits mask */
#define MAX3100_D(x) ((x) & 0x00FF) /* data bits */
/* these definitions are valid only for fOSC = 3.6864MHz */
#define MAX3100_B_230400 MAX3100_B(0)
#define MAX3100_B_115200 MAX3100_B(1)
#define MAX3100_B_57600 MAX3100_B(2)
#define MAX3100_B_38400 MAX3100_B(9)
#define MAX3100_B_19200 MAX3100_B(10)
#define MAX3100_B_9600 MAX3100_B(11)
#define MAX3100_B_4800 MAX3100_B(12)
#define MAX3100_B_2400 MAX3100_B(13)
#define MAX3100_B_1200 MAX3100_B(14)
#define MAX3100_B_600 MAX3100_B(15)
/**************************************************************/
static inline unsigned int max3100_transfer(unsigned int val)
{
unsigned int rx;
int b;
MAX3100_SPI_CLK(0);
MAX3100_CS(0);
rx = 0; b = 16;
while (--b >= 0) {
MAX3100_SPI_TXD(val & 0x8000);
val <<= 1;
MAX3100_SPI_CLK_TOGGLE();
udelay(1);
rx <<= 1;
if (MAX3100_SPI_RXD())
rx |= 1;
MAX3100_SPI_CLK_TOGGLE();
udelay(1);
}
MAX3100_SPI_CLK(1);
MAX3100_CS(1);
return rx;
}
/**************************************************************/
/* must be power of 2 */
#define RXFIFO_SZ 16
static int rxfifo_cnt;
static int rxfifo_in;
static int rxfifo_out;
static unsigned char rxfifo_buf[16];
static void max3100_serial_putc_raw(int c)
{
unsigned int rx;
while (((rx = max3100_transfer(MAX3100_RC)) & MAX3100_T) == 0)
WATCHDOG_RESET();
rx = max3100_transfer(MAX3100_WD | (c & 0xff));
if ((rx & MAX3100_RD) != 0 && rxfifo_cnt < RXFIFO_SZ) {
rxfifo_cnt++;
rxfifo_buf[rxfifo_in++] = rx & 0xff;
rxfifo_in &= RXFIFO_SZ - 1;
}
}
static int max3100_serial_getc(void)
{
int c;
unsigned int rx;
while (rxfifo_cnt == 0) {
rx = max3100_transfer(MAX3100_RD);
if ((rx & MAX3100_R) != 0) {
do {
rxfifo_cnt++;
rxfifo_buf[rxfifo_in++] = rx & 0xff;
rxfifo_in &= RXFIFO_SZ - 1;
if (rxfifo_cnt >= RXFIFO_SZ)
break;
} while (((rx = max3100_transfer(MAX3100_RD)) & MAX3100_R) != 0);
}
WATCHDOG_RESET();
}
rxfifo_cnt--;
c = rxfifo_buf[rxfifo_out++];
rxfifo_out &= RXFIFO_SZ - 1;
return c;
}
static int max3100_serial_tstc(void)
{
unsigned int rx;
if (rxfifo_cnt > 0)
return 1;
rx = max3100_transfer(MAX3100_RD);
if ((rx & MAX3100_R) == 0)
return 0;
do {
rxfifo_cnt++;
rxfifo_buf[rxfifo_in++] = rx & 0xff;
rxfifo_in &= RXFIFO_SZ - 1;
if (rxfifo_cnt >= RXFIFO_SZ)
break;
} while (((rx = max3100_transfer(MAX3100_RD)) & MAX3100_R) != 0);
return 1;
}
static int max3100_serial_init(void)
{
unsigned int wconf, rconf;
int i;
wconf = 0;
/* Set baud rate */
switch (gd->baudrate) {
case 1200:
wconf = MAX3100_B_1200;
break;
case 2400:
wconf = MAX3100_B_2400;
break;
case 4800:
wconf = MAX3100_B_4800;
break;
case 9600:
wconf = MAX3100_B_9600;
break;
case 19200:
wconf = MAX3100_B_19200;
break;
case 38400:
wconf = MAX3100_B_38400;
break;
case 57600:
wconf = MAX3100_B_57600;
break;
default:
case 115200:
wconf = MAX3100_B_115200;
break;
case 230400:
wconf = MAX3100_B_230400;
break;
}
/* try for 10ms, with a 100us gap */
for (i = 0; i < 10000; i += 100) {
max3100_transfer(MAX3100_WC | wconf);
rconf = max3100_transfer(MAX3100_RC) & 0x3fff;
if (rconf == wconf)
break;
udelay(100);
}
rxfifo_in = rxfifo_out = rxfifo_cnt = 0;
return (0);
}
static void max3100_serial_putc(const char c)
{
if (c == '\n')
max3100_serial_putc_raw('\r');
max3100_serial_putc_raw(c);
}
static void max3100_serial_puts(const char *s)
{
while (*s)
max3100_serial_putc_raw(*s++);
}
static void max3100_serial_setbrg(void)
{
}
#ifdef CONFIG_SERIAL_MULTI
static struct serial_device max3100_serial_drv = {
.name = "max3100_serial",
.start = max3100_serial_init,
.stop = NULL,
.setbrg = max3100_serial_setbrg,
.putc = max3100_serial_putc,
.puts = max3100_serial_puts,
.getc = max3100_serial_getc,
.tstc = max3100_serial_tstc,
};
void max3100_serial_initialize(void)
{
serial_register(&max3100_serial_drv);
}
__weak struct serial_device *default_serial_console(void)
{
return &max3100_serial_drv;
}
#else
int serial_init(void)
{
return max3100_serial_init();
}
void serial_setbrg(void)
{
max3100_serial_setbrg();
}
void serial_putc(const char c)
{
max3100_serial_putc(c);
}
void serial_puts(const char *s)
{
max3100_serial_puts(s);
}
int serial_getc(void)
{
return max3100_serial_getc();
}
int serial_tstc(void)
{
return max3100_serial_tstc();
}
#endif