serial_imx.c
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/*
* (c) 2004 Sascha Hauer <sascha@saschahauer.de>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <asm/arch/imx-regs.h>
#include <serial.h>
#include <linux/compiler.h>
#if defined CONFIG_IMX_SERIAL1
#define UART_BASE IMX_UART1_BASE
#elif defined CONFIG_IMX_SERIAL2
#define UART_BASE IMX_UART2_BASE
#else
#error "define CONFIG_IMX_SERIAL1, CONFIG_IMX_SERIAL2 or CONFIG_IMX_SERIAL_NONE"
#endif
struct imx_serial {
volatile uint32_t urxd[16];
volatile uint32_t utxd[16];
volatile uint32_t ucr1;
volatile uint32_t ucr2;
volatile uint32_t ucr3;
volatile uint32_t ucr4;
volatile uint32_t ufcr;
volatile uint32_t usr1;
volatile uint32_t usr2;
volatile uint32_t uesc;
volatile uint32_t utim;
volatile uint32_t ubir;
volatile uint32_t ubmr;
volatile uint32_t ubrc;
volatile uint32_t bipr[4];
volatile uint32_t bmpr[4];
volatile uint32_t uts;
};
DECLARE_GLOBAL_DATA_PTR;
static void imx_serial_setbrg(void)
{
serial_init();
}
extern void imx_gpio_mode(int gpio_mode);
/*
* 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 imx_serial_init(void)
{
volatile struct imx_serial* base = (struct imx_serial *)UART_BASE;
unsigned int ufcr_rfdiv;
unsigned int refclk;
#ifdef CONFIG_IMX_SERIAL1
imx_gpio_mode(PC11_PF_UART1_TXD);
imx_gpio_mode(PC12_PF_UART1_RXD);
#else
imx_gpio_mode(PB30_PF_UART2_TXD);
imx_gpio_mode(PB31_PF_UART2_RXD);
#endif
/* Disable UART */
base->ucr1 &= ~UCR1_UARTEN;
/* Set to default POR state */
base->ucr1 = 0x00000004;
base->ucr2 = 0x00000000;
base->ucr3 = 0x00000000;
base->ucr4 = 0x00008040;
base->uesc = 0x0000002B;
base->utim = 0x00000000;
base->ubir = 0x00000000;
base->ubmr = 0x00000000;
base->uts = 0x00000000;
/* Set clocks */
base->ucr4 |= UCR4_REF16;
/* Configure FIFOs */
base->ufcr = 0xa81;
/* set the baud rate.
*
* baud * 16 x
* --------- = -
* refclk y
*
* x - 1 = UBIR
* y - 1 = UBMR
*
* each register is 16 bits wide. refclk max is 96 MHz
*
*/
ufcr_rfdiv = ((base->ufcr) & UFCR_RFDIV) >> 7;
if (ufcr_rfdiv == 6)
ufcr_rfdiv = 7;
else
ufcr_rfdiv = 6 - ufcr_rfdiv;
refclk = get_PERCLK1();
refclk /= ufcr_rfdiv;
/* Set the numerator value minus one of the BRM ratio */
base->ubir = (gd->baudrate / 100) - 1;
/* Set the denominator value minus one of the BRM ratio */
base->ubmr = (refclk/(16 * 100)) - 1;
/* Set to 8N1 */
base->ucr2 &= ~UCR2_PREN;
base->ucr2 |= UCR2_WS;
base->ucr2 &= ~UCR2_STPB;
/* Ignore RTS */
base->ucr2 |= UCR2_IRTS;
/* Enable UART */
base->ucr1 |= UCR1_UARTEN | UCR1_UARTCLKEN;
/* Enable FIFOs */
base->ucr2 |= UCR2_SRST | UCR2_RXEN | UCR2_TXEN;
/* Clear status flags */
base->usr2 |= USR2_ADET |
USR2_DTRF |
USR2_IDLE |
USR2_IRINT |
USR2_WAKE |
USR2_RTSF |
USR2_BRCD |
USR2_ORE;
/* Clear status flags */
base->usr1 |= USR1_PARITYERR |
USR1_RTSD |
USR1_ESCF |
USR1_FRAMERR |
USR1_AIRINT |
USR1_AWAKE;
return (0);
}
/*
* Read a single byte from the serial port. Returns 1 on success, 0
* otherwise. When the function is successful, the character read is
* written into its argument c.
*/
static int imx_serial_getc(void)
{
volatile struct imx_serial* base = (struct imx_serial *)UART_BASE;
unsigned char ch;
while(base->uts & UTS_RXEMPTY);
ch = (char)base->urxd[0];
return ch;
}
#ifdef CONFIG_HWFLOW
static int hwflow = 0; /* turned off by default */
int hwflow_onoff(int on)
{
}
#endif
/*
* Output a single byte to the serial port.
*/
static void imx_serial_putc(const char c)
{
volatile struct imx_serial* base = (struct imx_serial *)UART_BASE;
/* Wait for Tx FIFO not full */
while (base->uts & UTS_TXFULL);
base->utxd[0] = c;
/* If \n, also do \r */
if (c == '\n')
serial_putc ('\r');
}
/*
* Test whether a character is in the RX buffer
*/
static int imx_serial_tstc(void)
{
volatile struct imx_serial* base = (struct imx_serial *)UART_BASE;
/* If receive fifo is empty, return false */
if (base->uts & UTS_RXEMPTY)
return 0;
return 1;
}
static struct serial_device imx_serial_drv = {
.name = "imx_serial",
.start = imx_serial_init,
.stop = NULL,
.setbrg = imx_serial_setbrg,
.putc = imx_serial_putc,
.puts = default_serial_puts,
.getc = imx_serial_getc,
.tstc = imx_serial_tstc,
};
void imx_serial_initialize(void)
{
serial_register(&imx_serial_drv);
}
__weak struct serial_device *default_serial_console(void)
{
return &imx_serial_drv;
}