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/*
* Copyright (C) 2012 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2011-2012 Xilinx, Inc. All rights reserved.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <watchdog.h>
#include <asm/io.h>
#include <linux/compiler.h>
#include <serial.h>
#define ZYNQ_UART_SR_TXFULL 0x00000010 /* TX FIFO full */
#define ZYNQ_UART_SR_RXEMPTY 0x00000002 /* RX FIFO empty */
#define ZYNQ_UART_CR_TX_EN 0x00000010 /* TX enabled */
#define ZYNQ_UART_CR_RX_EN 0x00000004 /* RX enabled */
#define ZYNQ_UART_CR_TXRST 0x00000002 /* TX logic reset */
#define ZYNQ_UART_CR_RXRST 0x00000001 /* RX logic reset */
#define ZYNQ_UART_MR_PARITY_NONE 0x00000020 /* No parity mode */
/* Some clock/baud constants */
#define ZYNQ_UART_BDIV 15 /* Default/reset BDIV value */
#define ZYNQ_UART_BASECLK 3125000L /* master / (bdiv + 1) */
struct uart_zynq {
u32 control; /* Control Register [8:0] */
u32 mode; /* Mode Register [10:0] */
u32 reserved1[4];
u32 baud_rate_gen; /* Baud Rate Generator [15:0] */
u32 reserved2[4];
u32 channel_sts; /* Channel Status [11:0] */
u32 tx_rx_fifo; /* FIFO [15:0] or [7:0] */
u32 baud_rate_divider; /* Baud Rate Divider [7:0] */
};
static struct uart_zynq *uart_zynq_ports[2] = {
#ifdef CONFIG_ZYNQ_SERIAL_BASEADDR0
[0] = (struct uart_zynq *)CONFIG_ZYNQ_SERIAL_BASEADDR0,
#endif
#ifdef CONFIG_ZYNQ_SERIAL_BASEADDR1
[1] = (struct uart_zynq *)CONFIG_ZYNQ_SERIAL_BASEADDR1,
#endif
};
struct uart_zynq_params {
u32 baudrate;
u32 clock;
};
static struct uart_zynq_params uart_zynq_ports_param[2] = {
#if defined(CONFIG_ZYNQ_SERIAL_BAUDRATE0) && defined(CONFIG_ZYNQ_SERIAL_CLOCK0)
[0].baudrate = CONFIG_ZYNQ_SERIAL_BAUDRATE0,
[0].clock = CONFIG_ZYNQ_SERIAL_CLOCK0,
#endif
#if defined(CONFIG_ZYNQ_SERIAL_BAUDRATE1) && defined(CONFIG_ZYNQ_SERIAL_CLOCK1)
[1].baudrate = CONFIG_ZYNQ_SERIAL_BAUDRATE1,
[1].clock = CONFIG_ZYNQ_SERIAL_CLOCK1,
#endif
};
/* Set up the baud rate in gd struct */
static void uart_zynq_serial_setbrg(const int port)
{
/* Calculation results. */
unsigned int calc_bauderror, bdiv, bgen;
unsigned long calc_baud = 0;
unsigned long baud = uart_zynq_ports_param[port].baudrate;
unsigned long clock = uart_zynq_ports_param[port].clock;
struct uart_zynq *regs = uart_zynq_ports[port];
/* master clock
* Baud rate = ------------------
* bgen * (bdiv + 1)
*
* Find acceptable values for baud generation.
*/
for (bdiv = 4; bdiv < 255; bdiv++) {
bgen = clock / (baud * (bdiv + 1));
if (bgen < 2 || bgen > 65535)
continue;
calc_baud = clock / (bgen * (bdiv + 1));
/*
* Use first calculated baudrate with
* an acceptable (<3%) error
*/
if (baud > calc_baud)
calc_bauderror = baud - calc_baud;
else
calc_bauderror = calc_baud - baud;
if (((calc_bauderror * 100) / baud) < 3)
break;
}
writel(bdiv, ®s->baud_rate_divider);
writel(bgen, ®s->baud_rate_gen);
}
/* Initialize the UART, with...some settings. */
static int uart_zynq_serial_init(const int port)
{
struct uart_zynq *regs = uart_zynq_ports[port];
if (!regs)
return -1;
/* RX/TX enabled & reset */
writel(ZYNQ_UART_CR_TX_EN | ZYNQ_UART_CR_RX_EN | ZYNQ_UART_CR_TXRST | \
ZYNQ_UART_CR_RXRST, ®s->control);
writel(ZYNQ_UART_MR_PARITY_NONE, ®s->mode); /* 8 bit, no parity */
uart_zynq_serial_setbrg(port);
return 0;
}
static void uart_zynq_serial_putc(const char c, const int port)
{
struct uart_zynq *regs = uart_zynq_ports[port];
while ((readl(®s->channel_sts) & ZYNQ_UART_SR_TXFULL) != 0)
WATCHDOG_RESET();
if (c == '\n') {
writel('\r', ®s->tx_rx_fifo);
while ((readl(®s->channel_sts) & ZYNQ_UART_SR_TXFULL) != 0)
WATCHDOG_RESET();
}
writel(c, ®s->tx_rx_fifo);
}
static void uart_zynq_serial_puts(const char *s, const int port)
{
while (*s)
uart_zynq_serial_putc(*s++, port);
}
static int uart_zynq_serial_tstc(const int port)
{
struct uart_zynq *regs = uart_zynq_ports[port];
return (readl(®s->channel_sts) & ZYNQ_UART_SR_RXEMPTY) == 0;
}
static int uart_zynq_serial_getc(const int port)
{
struct uart_zynq *regs = uart_zynq_ports[port];
while (!uart_zynq_serial_tstc(port))
WATCHDOG_RESET();
return readl(®s->tx_rx_fifo);
}
/* Multi serial device functions */
#define DECLARE_PSSERIAL_FUNCTIONS(port) \
int uart_zynq##port##_init(void) \
{ return uart_zynq_serial_init(port); } \
void uart_zynq##port##_setbrg(void) \
{ return uart_zynq_serial_setbrg(port); } \
int uart_zynq##port##_getc(void) \
{ return uart_zynq_serial_getc(port); } \
int uart_zynq##port##_tstc(void) \
{ return uart_zynq_serial_tstc(port); } \
void uart_zynq##port##_putc(const char c) \
{ uart_zynq_serial_putc(c, port); } \
void uart_zynq##port##_puts(const char *s) \
{ uart_zynq_serial_puts(s, port); }
/* Serial device descriptor */
#define INIT_PSSERIAL_STRUCTURE(port, __name) { \
.name = __name, \
.start = uart_zynq##port##_init, \
.stop = NULL, \
.setbrg = uart_zynq##port##_setbrg, \
.getc = uart_zynq##port##_getc, \
.tstc = uart_zynq##port##_tstc, \
.putc = uart_zynq##port##_putc, \
.puts = uart_zynq##port##_puts, \
}
DECLARE_PSSERIAL_FUNCTIONS(0);
struct serial_device uart_zynq_serial0_device =
INIT_PSSERIAL_STRUCTURE(0, "ttyPS0");
DECLARE_PSSERIAL_FUNCTIONS(1);
struct serial_device uart_zynq_serial1_device =
INIT_PSSERIAL_STRUCTURE(1, "ttyPS1");
__weak struct serial_device *default_serial_console(void)
{
if (uart_zynq_ports[0])
return &uart_zynq_serial0_device;
if (uart_zynq_ports[1])
return &uart_zynq_serial1_device;
return NULL;
}
void zynq_serial_initalize(void)
{
#ifdef CONFIG_ZYNQ_SERIAL_BASEADDR0
serial_register(&uart_zynq_serial0_device);
#endif
#ifdef CONFIG_ZYNQ_SERIAL_BASEADDR1
serial_register(&uart_zynq_serial1_device);
#endif
}
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