u-boot/drivers/serial/serial_pl01x.c

355 lines
7.4 KiB
C
Raw Normal View History

/*
* (C) Copyright 2000
* Rob Taylor, Flying Pig Systems. robt@flyingpig.com.
*
* (C) Copyright 2004
* ARM Ltd.
* Philippe Robin, <philippe.robin@arm.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
/* Simple U-Boot driver for the PrimeCell PL010/PL011 UARTs */
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <watchdog.h>
#include <asm/io.h>
#include <serial.h>
#include <dm/platform_data/serial_pl01x.h>
#include <linux/compiler.h>
#include "serial_pl01x_internal.h"
#ifndef CONFIG_DM_SERIAL
static volatile unsigned char *const port[] = CONFIG_PL01x_PORTS;
static enum pl01x_type pl01x_type __attribute__ ((section(".data")));
static struct pl01x_regs *base_regs __attribute__ ((section(".data")));
#define NUM_PORTS (sizeof(port)/sizeof(port[0]))
DECLARE_GLOBAL_DATA_PTR;
#endif
static int pl01x_putc(struct pl01x_regs *regs, char c)
{
/* Wait until there is space in the FIFO */
if (readl(&regs->fr) & UART_PL01x_FR_TXFF)
return -EAGAIN;
/* Send the character */
writel(c, &regs->dr);
return 0;
}
static int pl01x_getc(struct pl01x_regs *regs)
{
unsigned int data;
/* Wait until there is data in the FIFO */
if (readl(&regs->fr) & UART_PL01x_FR_RXFE)
return -EAGAIN;
data = readl(&regs->dr);
/* Check for an error flag */
if (data & 0xFFFFFF00) {
/* Clear the error */
writel(0xFFFFFFFF, &regs->ecr);
return -1;
}
return (int) data;
}
static int pl01x_tstc(struct pl01x_regs *regs)
{
WATCHDOG_RESET();
return !(readl(&regs->fr) & UART_PL01x_FR_RXFE);
}
static int pl01x_generic_serial_init(struct pl01x_regs *regs,
enum pl01x_type type)
{
switch (type) {
case TYPE_PL010:
/* disable everything */
writel(0, &regs->pl010_cr);
break;
case TYPE_PL011:
#ifdef CONFIG_PL011_SERIAL_FLUSH_ON_INIT
/* Empty RX fifo if necessary */
if (readl(&regs->pl011_cr) & UART_PL011_CR_UARTEN) {
while (!(readl(&regs->fr) & UART_PL01x_FR_RXFE))
readl(&regs->dr);
}
#endif
/* disable everything */
writel(0, &regs->pl011_cr);
break;
default:
return -EINVAL;
}
return 0;
}
static int set_line_control(struct pl01x_regs *regs)
{
unsigned int lcr;
/*
* Internal update of baud rate register require line
* control register write
*/
lcr = UART_PL011_LCRH_WLEN_8 | UART_PL011_LCRH_FEN;
#ifdef CONFIG_PL011_SERIAL_RLCR
{
int i;
/*
* Program receive line control register after waiting
* 10 bus cycles. Delay be writing to readonly register
* 10 times
*/
for (i = 0; i < 10; i++)
writel(lcr, &regs->fr);
writel(lcr, &regs->pl011_rlcr);
}
#endif
writel(lcr, &regs->pl011_lcrh);
return 0;
}
static int pl01x_generic_setbrg(struct pl01x_regs *regs, enum pl01x_type type,
int clock, int baudrate)
{
switch (type) {
case TYPE_PL010: {
unsigned int divisor;
switch (baudrate) {
case 9600:
divisor = UART_PL010_BAUD_9600;
break;
case 19200:
divisor = UART_PL010_BAUD_9600;
break;
case 38400:
divisor = UART_PL010_BAUD_38400;
break;
case 57600:
divisor = UART_PL010_BAUD_57600;
break;
case 115200:
divisor = UART_PL010_BAUD_115200;
break;
default:
divisor = UART_PL010_BAUD_38400;
}
writel((divisor & 0xf00) >> 8, &regs->pl010_lcrm);
writel(divisor & 0xff, &regs->pl010_lcrl);
/* Finally, enable the UART */
writel(UART_PL010_CR_UARTEN, &regs->pl010_cr);
break;
}
case TYPE_PL011: {
unsigned int temp;
unsigned int divider;
unsigned int remainder;
unsigned int fraction;
/*
* Set baud rate
*
* IBRD = UART_CLK / (16 * BAUD_RATE)
* FBRD = RND((64 * MOD(UART_CLK,(16 * BAUD_RATE)))
* / (16 * BAUD_RATE))
*/
temp = 16 * baudrate;
divider = clock / temp;
remainder = clock % temp;
temp = (8 * remainder) / baudrate;
fraction = (temp >> 1) + (temp & 1);
writel(divider, &regs->pl011_ibrd);
writel(fraction, &regs->pl011_fbrd);
set_line_control(regs);
/* Finally, enable the UART */
writel(UART_PL011_CR_UARTEN | UART_PL011_CR_TXE |
UART_PL011_CR_RXE | UART_PL011_CR_RTS, &regs->pl011_cr);
break;
}
default:
return -EINVAL;
}
return 0;
}
#ifndef CONFIG_DM_SERIAL
static void pl01x_serial_init_baud(int baudrate)
{
int clock = 0;
#if defined(CONFIG_PL010_SERIAL)
pl01x_type = TYPE_PL010;
#elif defined(CONFIG_PL011_SERIAL)
pl01x_type = TYPE_PL011;
clock = CONFIG_PL011_CLOCK;
#endif
base_regs = (struct pl01x_regs *)port[CONFIG_CONS_INDEX];
pl01x_generic_serial_init(base_regs, pl01x_type);
pl01x_generic_setbrg(base_regs, pl01x_type, clock, baudrate);
}
/*
* Integrator AP has two UARTs, we use the first one, at 38400-8-N-1
* Integrator CP has two UARTs, use the first one, at 38400-8-N-1
* Versatile PB has four UARTs.
*/
int pl01x_serial_init(void)
{
pl01x_serial_init_baud(CONFIG_BAUDRATE);
return 0;
}
static void pl01x_serial_putc(const char c)
{
if (c == '\n')
while (pl01x_putc(base_regs, '\r') == -EAGAIN);
while (pl01x_putc(base_regs, c) == -EAGAIN);
}
static int pl01x_serial_getc(void)
{
while (1) {
int ch = pl01x_getc(base_regs);
if (ch == -EAGAIN) {
WATCHDOG_RESET();
continue;
}
return ch;
}
}
static int pl01x_serial_tstc(void)
{
return pl01x_tstc(base_regs);
}
static void pl01x_serial_setbrg(void)
{
/*
* Flush FIFO and wait for non-busy before changing baudrate to avoid
* crap in console
*/
while (!(readl(&base_regs->fr) & UART_PL01x_FR_TXFE))
WATCHDOG_RESET();
while (readl(&base_regs->fr) & UART_PL01x_FR_BUSY)
WATCHDOG_RESET();
pl01x_serial_init_baud(gd->baudrate);
}
static struct serial_device pl01x_serial_drv = {
.name = "pl01x_serial",
.start = pl01x_serial_init,
.stop = NULL,
.setbrg = pl01x_serial_setbrg,
.putc = pl01x_serial_putc,
.puts = default_serial_puts,
.getc = pl01x_serial_getc,
.tstc = pl01x_serial_tstc,
};
void pl01x_serial_initialize(void)
{
serial_register(&pl01x_serial_drv);
}
__weak struct serial_device *default_serial_console(void)
{
return &pl01x_serial_drv;
}
#endif /* nCONFIG_DM_SERIAL */
#ifdef CONFIG_DM_SERIAL
struct pl01x_priv {
struct pl01x_regs *regs;
enum pl01x_type type;
};
static int pl01x_serial_setbrg(struct udevice *dev, int baudrate)
{
struct pl01x_serial_platdata *plat = dev_get_platdata(dev);
struct pl01x_priv *priv = dev_get_priv(dev);
pl01x_generic_setbrg(priv->regs, priv->type, plat->clock, baudrate);
return 0;
}
static int pl01x_serial_probe(struct udevice *dev)
{
struct pl01x_serial_platdata *plat = dev_get_platdata(dev);
struct pl01x_priv *priv = dev_get_priv(dev);
priv->regs = (struct pl01x_regs *)plat->base;
priv->type = plat->type;
return pl01x_generic_serial_init(priv->regs, priv->type);
}
static int pl01x_serial_getc(struct udevice *dev)
{
struct pl01x_priv *priv = dev_get_priv(dev);
return pl01x_getc(priv->regs);
}
static int pl01x_serial_putc(struct udevice *dev, const char ch)
{
struct pl01x_priv *priv = dev_get_priv(dev);
return pl01x_putc(priv->regs, ch);
}
static int pl01x_serial_pending(struct udevice *dev, bool input)
{
struct pl01x_priv *priv = dev_get_priv(dev);
unsigned int fr = readl(&priv->regs->fr);
if (input)
return pl01x_tstc(priv->regs);
else
return fr & UART_PL01x_FR_TXFF ? 0 : 1;
}
static const struct dm_serial_ops pl01x_serial_ops = {
.putc = pl01x_serial_putc,
.pending = pl01x_serial_pending,
.getc = pl01x_serial_getc,
.setbrg = pl01x_serial_setbrg,
};
U_BOOT_DRIVER(serial_pl01x) = {
.name = "serial_pl01x",
.id = UCLASS_SERIAL,
.probe = pl01x_serial_probe,
.ops = &pl01x_serial_ops,
.flags = DM_FLAG_PRE_RELOC,
.priv_auto_alloc_size = sizeof(struct pl01x_priv),
};
#endif