u-boot/drivers/serial/serial_lpuart.c

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/*
* Copyright 2013 Freescale Semiconductor, Inc.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <watchdog.h>
#include <asm/io.h>
#include <serial.h>
#include <linux/compiler.h>
#include <asm/arch/imx-regs.h>
#include <asm/arch/clock.h>
#define US1_TDRE (1 << 7)
#define US1_RDRF (1 << 5)
#define US1_OR (1 << 3)
#define UC2_TE (1 << 3)
#define UC2_RE (1 << 2)
#define CFIFO_TXFLUSH (1 << 7)
#define CFIFO_RXFLUSH (1 << 6)
#define SFIFO_RXOF (1 << 2)
#define SFIFO_RXUF (1 << 0)
#define STAT_LBKDIF (1 << 31)
#define STAT_RXEDGIF (1 << 30)
#define STAT_TDRE (1 << 23)
#define STAT_RDRF (1 << 21)
#define STAT_IDLE (1 << 20)
#define STAT_OR (1 << 19)
#define STAT_NF (1 << 18)
#define STAT_FE (1 << 17)
#define STAT_PF (1 << 16)
#define STAT_MA1F (1 << 15)
#define STAT_MA2F (1 << 14)
#define STAT_FLAGS (STAT_LBKDIF | STAT_RXEDGIF | STAT_IDLE | STAT_OR | \
STAT_NF | STAT_FE | STAT_PF | STAT_MA1F | STAT_MA2F)
#define CTRL_TE (1 << 19)
#define CTRL_RE (1 << 18)
#define FIFO_TXFE 0x80
#define FIFO_RXFE 0x40
#define WATER_TXWATER_OFF 1
#define WATER_RXWATER_OFF 16
DECLARE_GLOBAL_DATA_PTR;
struct lpuart_fsl *base = (struct lpuart_fsl *)LPUART_BASE;
#ifndef CONFIG_LPUART_32B_REG
static void lpuart_serial_setbrg(void)
{
u32 clk = mxc_get_clock(MXC_UART_CLK);
u16 sbr;
if (!gd->baudrate)
gd->baudrate = CONFIG_BAUDRATE;
sbr = (u16)(clk / (16 * gd->baudrate));
/* place adjustment later - n/32 BRFA */
__raw_writeb(sbr >> 8, &base->ubdh);
__raw_writeb(sbr & 0xff, &base->ubdl);
}
static int lpuart_serial_getc(void)
{
while (!(__raw_readb(&base->us1) & (US1_RDRF | US1_OR)))
WATCHDOG_RESET();
barrier();
return __raw_readb(&base->ud);
}
static void lpuart_serial_putc(const char c)
{
if (c == '\n')
lpuart_serial_putc('\r');
while (!(__raw_readb(&base->us1) & US1_TDRE))
WATCHDOG_RESET();
__raw_writeb(c, &base->ud);
}
/* Test whether a character is in the RX buffer */
static int lpuart_serial_tstc(void)
{
if (__raw_readb(&base->urcfifo) == 0)
return 0;
return 1;
}
/*
* Initialise the serial port with the given baudrate. The settings
* are always 8 data bits, no parity, 1 stop bit, no start bits.
*/
static int lpuart_serial_init(void)
{
u8 ctrl;
ctrl = __raw_readb(&base->uc2);
ctrl &= ~UC2_RE;
ctrl &= ~UC2_TE;
__raw_writeb(ctrl, &base->uc2);
__raw_writeb(0, &base->umodem);
__raw_writeb(0, &base->uc1);
/* Disable FIFO and flush buffer */
__raw_writeb(0x0, &base->upfifo);
__raw_writeb(0x0, &base->utwfifo);
__raw_writeb(0x1, &base->urwfifo);
__raw_writeb(CFIFO_TXFLUSH | CFIFO_RXFLUSH, &base->ucfifo);
/* provide data bits, parity, stop bit, etc */
lpuart_serial_setbrg();
__raw_writeb(UC2_RE | UC2_TE, &base->uc2);
return 0;
}
static struct serial_device lpuart_serial_drv = {
.name = "lpuart_serial",
.start = lpuart_serial_init,
.stop = NULL,
.setbrg = lpuart_serial_setbrg,
.putc = lpuart_serial_putc,
.puts = default_serial_puts,
.getc = lpuart_serial_getc,
.tstc = lpuart_serial_tstc,
};
#else
static void lpuart32_serial_setbrg(void)
{
u32 clk = CONFIG_SYS_CLK_FREQ;
u32 sbr;
if (!gd->baudrate)
gd->baudrate = CONFIG_BAUDRATE;
sbr = (clk / (16 * gd->baudrate));
/* place adjustment later - n/32 BRFA */
out_be32(&base->baud, sbr);
}
static int lpuart32_serial_getc(void)
{
u32 stat;
while (((stat = in_be32(&base->stat)) & STAT_RDRF) == 0) {
out_be32(&base->stat, STAT_FLAGS);
WATCHDOG_RESET();
}
return in_be32(&base->data) & 0x3ff;
}
static void lpuart32_serial_putc(const char c)
{
if (c == '\n')
lpuart32_serial_putc('\r');
while (!(in_be32(&base->stat) & STAT_TDRE))
WATCHDOG_RESET();
out_be32(&base->data, c);
}
/* Test whether a character is in the RX buffer */
static int lpuart32_serial_tstc(void)
{
if ((in_be32(&base->water) >> 24) == 0)
return 0;
return 1;
}
/*
* Initialise the serial port with the given baudrate. The settings
* are always 8 data bits, no parity, 1 stop bit, no start bits.
*/
static int lpuart32_serial_init(void)
{
u8 ctrl;
ctrl = in_be32(&base->ctrl);
ctrl &= ~CTRL_RE;
ctrl &= ~CTRL_TE;
out_be32(&base->ctrl, ctrl);
out_be32(&base->modir, 0);
out_be32(&base->fifo, ~(FIFO_TXFE | FIFO_RXFE));
out_be32(&base->match, 0);
/* provide data bits, parity, stop bit, etc */
lpuart32_serial_setbrg();
out_be32(&base->ctrl, CTRL_RE | CTRL_TE);
return 0;
}
static struct serial_device lpuart32_serial_drv = {
.name = "lpuart32_serial",
.start = lpuart32_serial_init,
.stop = NULL,
.setbrg = lpuart32_serial_setbrg,
.putc = lpuart32_serial_putc,
.puts = default_serial_puts,
.getc = lpuart32_serial_getc,
.tstc = lpuart32_serial_tstc,
};
#endif
void lpuart_serial_initialize(void)
{
#ifdef CONFIG_LPUART_32B_REG
serial_register(&lpuart32_serial_drv);
#else
serial_register(&lpuart_serial_drv);
#endif
}
__weak struct serial_device *default_serial_console(void)
{
#ifdef CONFIG_LPUART_32B_REG
return &lpuart32_serial_drv;
#else
return &lpuart_serial_drv;
#endif
}