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nuttx/drivers/serial/uart_16550.c
Alin Jerpelea e5b6305f4a drivers: Author Gregory Nutt: update licenses to Apache 
Gregory Nutt has submitted the SGA and we can migrate the licenses
 to Apache.

Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
2021-03-04 18:32:27 -08:00

1362 lines
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/****************************************************************************
* drivers/serial/uart_16550.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/* Serial driver for 16550 UART */
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/irq.h>
#include <nuttx/arch.h>
#include <nuttx/serial/serial.h>
#include <nuttx/fs/ioctl.h>
#include <nuttx/serial/uart_16550.h>
#include <arch/board/board.h>
#ifdef CONFIG_16550_UART
/****************************************************************************
* Pre-processor definitions
****************************************************************************/
/****************************************************************************
* Private Types
****************************************************************************/
struct u16550_s
{
uart_addrwidth_t uartbase; /* Base address of UART registers */
#ifndef CONFIG_16550_SUPRESS_CONFIG
uint32_t baud; /* Configured baud */
uint32_t uartclk; /* UART clock frequency */
#endif
uart_datawidth_t ier; /* Saved IER value */
uint8_t irq; /* IRQ associated with this UART */
#ifndef CONFIG_16550_SUPRESS_CONFIG
uint8_t parity; /* 0=none, 1=odd, 2=even */
uint8_t bits; /* Number of bits (7 or 8) */
bool stopbits2; /* true: Configure with 2 stop bits instead of 1 */
#if defined(CONFIG_SERIAL_IFLOWCONTROL) || defined(CONFIG_SERIAL_OFLOWCONTROL)
bool flow; /* flow control (RTS/CTS) enabled */
#endif
#endif
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static int u16550_setup(FAR struct uart_dev_s *dev);
static void u16550_shutdown(FAR struct uart_dev_s *dev);
static int u16550_attach(FAR struct uart_dev_s *dev);
static void u16550_detach(FAR struct uart_dev_s *dev);
static int u16550_interrupt(int irq, FAR void *context, FAR void *arg);
static int u16550_ioctl(FAR struct file *filep, int cmd, unsigned long arg);
static int u16550_receive(FAR struct uart_dev_s *dev, unsigned int *status);
static void u16550_rxint(FAR struct uart_dev_s *dev, bool enable);
static bool u16550_rxavailable(FAR struct uart_dev_s *dev);
#ifdef CONFIG_SERIAL_IFLOWCONTROL
static bool u16550_rxflowcontrol(struct uart_dev_s *dev,
unsigned int nbuffered, bool upper);
#endif
#ifdef CONFIG_SERIAL_TXDMA
static void u16550_dmasend(FAR struct uart_dev_s *dev);
static void u16550_dmatxavail(FAR struct uart_dev_s *dev);
#endif
#ifdef CONFIG_SERIAL_RXDMA
static void u16550_dmareceive(FAR struct uart_dev_s *dev);
static void u16550_dmarxfree(FAR struct uart_dev_s *dev);
#endif
static void u16550_send(FAR struct uart_dev_s *dev, int ch);
static void u16550_txint(FAR struct uart_dev_s *dev, bool enable);
static bool u16550_txready(FAR struct uart_dev_s *dev);
static bool u16550_txempty(FAR struct uart_dev_s *dev);
/****************************************************************************
* Private Data
****************************************************************************/
static const struct uart_ops_s g_uart_ops =
{
.setup = u16550_setup,
.shutdown = u16550_shutdown,
.attach = u16550_attach,
.detach = u16550_detach,
.ioctl = u16550_ioctl,
.receive = u16550_receive,
.rxint = u16550_rxint,
.rxavailable = u16550_rxavailable,
#ifdef CONFIG_SERIAL_IFLOWCONTROL
.rxflowcontrol = u16550_rxflowcontrol,
#endif
#ifdef CONFIG_SERIAL_TXDMA
.dmasend = u16550_dmasend,
#endif
#ifdef CONFIG_SERIAL_RXDMA
.dmareceive = u16550_dmareceive,
.dmarxfree = u16550_dmarxfree,
#endif
#ifdef CONFIG_SERIAL_TXDMA
.dmatxavail = u16550_dmatxavail,
#endif
.send = u16550_send,
.txint = u16550_txint,
.txready = u16550_txready,
.txempty = u16550_txempty,
};
/* I/O buffers */
#ifdef CONFIG_16550_UART0
static char g_uart0rxbuffer[CONFIG_16550_UART0_RXBUFSIZE];
static char g_uart0txbuffer[CONFIG_16550_UART0_TXBUFSIZE];
#endif
#ifdef CONFIG_16550_UART1
static char g_uart1rxbuffer[CONFIG_16550_UART1_RXBUFSIZE];
static char g_uart1txbuffer[CONFIG_16550_UART1_TXBUFSIZE];
#endif
#ifdef CONFIG_16550_UART2
static char g_uart2rxbuffer[CONFIG_16550_UART2_RXBUFSIZE];
static char g_uart2txbuffer[CONFIG_16550_UART2_TXBUFSIZE];
#endif
#ifdef CONFIG_16550_UART3
static char g_uart3rxbuffer[CONFIG_16550_UART3_RXBUFSIZE];
static char g_uart3txbuffer[CONFIG_16550_UART3_TXBUFSIZE];
#endif
/* This describes the state of the 16550 uart0 port. */
#ifdef CONFIG_16550_UART0
static struct u16550_s g_uart0priv =
{
.uartbase = CONFIG_16550_UART0_BASE,
#ifndef CONFIG_16550_SUPRESS_CONFIG
.baud = CONFIG_16550_UART0_BAUD,
.uartclk = CONFIG_16550_UART0_CLOCK,
#endif
.irq = CONFIG_16550_UART0_IRQ,
#ifndef CONFIG_16550_SUPRESS_CONFIG
.parity = CONFIG_16550_UART0_PARITY,
.bits = CONFIG_16550_UART0_BITS,
.stopbits2 = CONFIG_16550_UART0_2STOP,
#if defined(CONFIG_16550_UART0_IFLOWCONTROL) || defined(CONFIG_16550_UART0_OFLOWCONTROL)
.flow = true,
#endif
#endif
};
static uart_dev_t g_uart0port =
{
.recv =
{
.size = CONFIG_16550_UART0_RXBUFSIZE,
.buffer = g_uart0rxbuffer,
},
.xmit =
{
.size = CONFIG_16550_UART0_TXBUFSIZE,
.buffer = g_uart0txbuffer,
},
.ops = &g_uart_ops,
.priv = &g_uart0priv,
};
#endif
/* This describes the state of the 16550 uart1 port. */
#ifdef CONFIG_16550_UART1
static struct u16550_s g_uart1priv =
{
.uartbase = CONFIG_16550_UART1_BASE,
#ifndef CONFIG_16550_SUPRESS_CONFIG
.baud = CONFIG_16550_UART1_BAUD,
.uartclk = CONFIG_16550_UART1_CLOCK,
#endif
.irq = CONFIG_16550_UART1_IRQ,
#ifndef CONFIG_16550_SUPRESS_CONFIG
.parity = CONFIG_16550_UART1_PARITY,
.bits = CONFIG_16550_UART1_BITS,
.stopbits2 = CONFIG_16550_UART1_2STOP,
#if defined(CONFIG_16550_UART1_IFLOWCONTROL) || defined(CONFIG_16550_UART1_OFLOWCONTROL)
.flow = true,
#endif
#endif
};
static uart_dev_t g_uart1port =
{
.recv =
{
.size = CONFIG_16550_UART1_RXBUFSIZE,
.buffer = g_uart1rxbuffer,
},
.xmit =
{
.size = CONFIG_16550_UART1_TXBUFSIZE,
.buffer = g_uart1txbuffer,
},
.ops = &g_uart_ops,
.priv = &g_uart1priv,
};
#endif
/* This describes the state of the 16550 uart1 port. */
#ifdef CONFIG_16550_UART2
static struct u16550_s g_uart2priv =
{
.uartbase = CONFIG_16550_UART2_BASE,
#ifndef CONFIG_16550_SUPRESS_CONFIG
.baud = CONFIG_16550_UART2_BAUD,
.uartclk = CONFIG_16550_UART2_CLOCK,
#endif
.irq = CONFIG_16550_UART2_IRQ,
#ifndef CONFIG_16550_SUPRESS_CONFIG
.parity = CONFIG_16550_UART2_PARITY,
.bits = CONFIG_16550_UART2_BITS,
.stopbits2 = CONFIG_16550_UART2_2STOP,
#if defined(CONFIG_16550_UART2_IFLOWCONTROL) || defined(CONFIG_16550_UART2_OFLOWCONTROL)
.flow = true,
#endif
#endif
};
static uart_dev_t g_uart2port =
{
.recv =
{
.size = CONFIG_16550_UART2_RXBUFSIZE,
.buffer = g_uart2rxbuffer,
},
.xmit =
{
.size = CONFIG_16550_UART2_TXBUFSIZE,
.buffer = g_uart2txbuffer,
},
.ops = &g_uart_ops,
.priv = &g_uart2priv,
};
#endif
/* This describes the state of the 16550 uart1 port. */
#ifdef CONFIG_16550_UART3
static struct u16550_s g_uart3priv =
{
.uartbase = CONFIG_16550_UART3_BASE,
#ifndef CONFIG_16550_SUPRESS_CONFIG
.baud = CONFIG_16550_UART3_BAUD,
.uartclk = CONFIG_16550_UART3_CLOCK,
#endif
.irq = CONFIG_16550_UART3_IRQ,
#ifndef CONFIG_16550_SUPRESS_CONFIG
.parity = CONFIG_16550_UART3_PARITY,
.bits = CONFIG_16550_UART3_BITS,
.stopbits2 = CONFIG_16550_UART3_2STOP,
#if defined(CONFIG_16550_UART3_IFLOWCONTROL) || defined(CONFIG_16550_UART3_OFLOWCONTROL)
.flow = true,
#endif
#endif
};
static uart_dev_t g_uart3port =
{
.recv =
{
.size = CONFIG_16550_UART3_RXBUFSIZE,
.buffer = g_uart3rxbuffer,
},
.xmit =
{
.size = CONFIG_16550_UART3_TXBUFSIZE,
.buffer = g_uart3txbuffer,
},
.ops = &g_uart_ops,
.priv = &g_uart3priv,
};
#endif
/* Which UART with be tty0/console and which tty1? tty2? tty3? */
#ifdef CONFIG_16550_SERIAL_DISABLE_REORDERING
# if defined(CONFIG_16550_UART0_SERIAL_CONSOLE)
# define CONSOLE_DEV g_uart0port /* UART0=console */
# elif defined(CONFIG_16550_UART1_SERIAL_CONSOLE)
# define CONSOLE_DEV g_uart1port /* UART1=console */
# elif defined(CONFIG_16550_UART2_SERIAL_CONSOLE)
# define CONSOLE_DEV g_uart2port /* UART2=console */
# elif defined(CONFIG_16550_UART3_SERIAL_CONSOLE)
# define CONSOLE_DEV g_uart3port /* UART3=console */
# endif
# ifdef CONFIG_16550_UART0
# define TTYS0_DEV g_uart0port
# endif
# ifdef CONFIG_16550_UART1
# define TTYS1_DEV g_uart1port
# endif
# ifdef CONFIG_16550_UART2
# define TTYS2_DEV g_uart2port
# endif
# ifdef CONFIG_16550_UART3
# define TTYS3_DEV g_uart3port
# endif
#else /* CONFIG_16550_SERIAL_DISABLE_REORDERING */
/* Which UART with be tty0/console and which tty1? tty2? tty3? */
# if defined(CONFIG_16550_UART0_SERIAL_CONSOLE)
# define CONSOLE_DEV g_uart0port /* UART0=console */
# define TTYS0_DEV g_uart0port /* UART0=ttyS0 */
# ifdef CONFIG_16550_UART1
# define TTYS1_DEV g_uart1port /* UART0=ttyS0;UART1=ttyS1 */
# ifdef CONFIG_16550_UART2
# define TTYS2_DEV g_uart2port /* UART0=ttyS0;UART1=ttyS1;UART2=ttyS2 */
# ifdef CONFIG_16550_UART3
# define TTYS3_DEV g_uart3port /* UART0=ttyS0;UART1=ttyS1;UART2=ttyS2;UART3=ttyS3 */
# else
# undef TTYS3_DEV /* UART0=ttyS0;UART1=ttyS1;UART2=ttyS;No ttyS3 */
# endif
# else
# ifdef CONFIG_16550_UART3
# define TTYS2_DEV g_uart3port /* UART0=ttyS0;UART1=ttyS1;UART3=ttys2;No ttyS3 */
# else
# undef TTYS2_DEV /* UART0=ttyS0;UART1=ttyS1;No ttyS2;No ttyS3 */
# endif
# undef TTYS3_DEV /* No ttyS3 */
# endif
# else
# ifdef CONFIG_16550_UART2
# define TTYS1_DEV g_uart2port /* UART0=ttyS0;UART2=ttyS1;No ttyS3 */
# ifdef CONFIG_16550_UART3
# define TTYS2_DEV g_uart3port /* UART0=ttyS0;UART2=ttyS1;UART3=ttyS2;No ttyS3 */
# else
# undef TTYS2_DEV /* UART0=ttyS0;UART2=ttyS1;No ttyS2;No ttyS3 */
# endif
# undef TTYS3_DEV /* No ttyS3 */
# else
# ifdef CONFIG_16550_UART3
# define TTYS1_DEV g_uart3port /* UART0=ttyS0;UART3=ttyS1;No ttyS2;No ttyS3 */
# else
# undef TTYS1_DEV /* UART0=ttyS0;No ttyS1;No ttyS2;No ttyS3 */
# endif
# undef TTYS2_DEV /* No ttyS2 */
# undef TTYS3_DEV /* No ttyS3 */
# endif
# endif
# elif defined(CONFIG_16550_UART1_SERIAL_CONSOLE)
# define CONSOLE_DEV g_uart1port /* UART1=console */
# define TTYS0_DEV g_uart1port /* UART1=ttyS0 */
# ifdef CONFIG_16550_UART0
# define TTYS1_DEV g_uart0port /* UART1=ttyS0;UART0=ttyS1 */
# ifdef CONFIG_16550_UART2
# define TTYS2_DEV g_uart2port /* UART1=ttyS0;UART0=ttyS1;UART2=ttyS2 */
# ifdef CONFIG_16550_UART3
# define TTYS3_DEV g_uart3port /* UART1=ttyS0;UART0=ttyS1;UART2=ttyS2;UART3=ttyS3 */
# else
# undef TTYS3_DEV /* UART1=ttyS0;UART0=ttyS1;UART2=ttyS;No ttyS3 */
# endif
# else
# ifdef CONFIG_16550_UART3
# define TTYS2_DEV g_uart3port /* UART1=ttyS0;UART0=ttyS1;UART3=ttys2;No ttyS3 */
# else
# undef TTYS2_DEV /* UART1=ttyS0;UART0=ttyS1;No ttyS2;No ttyS3 */
# endif
# undef TTYS3_DEV /* No ttyS3 */
# endif
# else
# ifdef CONFIG_16550_UART2
# define TTYS1_DEV g_uart2port /* UART1=ttyS0;UART2=ttyS1 */
# ifdef CONFIG_16550_UART3
# define TTYS2_DEV g_uart3port /* UART1=ttyS0;UART2=ttyS1;UART3=ttyS2;No ttyS3 */
# else
# undef TTYS2_DEV /* UART1=ttyS0;UART2=ttyS1;No ttyS2;No ttyS3 */
# endif
# undef TTYS3_DEV /* No ttyS3 */
# else
# ifdef CONFIG_16550_UART3
# define TTYS1_DEV g_uart3port /* UART1=ttyS0;UART3=ttyS1;No ttyS2;No ttyS3 */
# else
# undef TTYS1_DEV /* UART1=ttyS0;No ttyS1;No ttyS2;No ttyS3 */
# endif
# undef TTYS2_DEV /* No ttyS2 */
# undef TTYS3_DEV /* No ttyS3 */
# endif
# endif
# elif defined(CONFIG_16550_UART2_SERIAL_CONSOLE)
# define CONSOLE_DEV g_uart2port /* UART2=console */
# define TTYS0_DEV g_uart2port /* UART2=ttyS0 */
# ifdef CONFIG_16550_UART0
# define TTYS1_DEV g_uart0port /* UART2=ttyS0;UART0=ttyS1 */
# ifdef CONFIG_16550_UART1
# define TTYS2_DEV g_uart1port /* UART2=ttyS0;UART0=ttyS1;UART1=ttyS2 */
# ifdef CONFIG_16550_UART3
# define TTYS3_DEV g_uart3port /* UART2=ttyS0;UART0=ttyS1;UART1=ttyS2;UART3=ttyS3 */
# else
# undef TTYS3_DEV /* UART2=ttyS0;UART0=ttyS1;UART1=ttyS;No ttyS3 */
# endif
# else
# ifdef CONFIG_16550_UART3
# define TTYS2_DEV g_uart3port /* UART2=ttyS0;UART0=ttyS1;UART3=ttys2;No ttyS3 */
# else
# undef TTYS2_DEV /* UART2=ttyS0;UART0=ttyS1;No ttyS2;No ttyS3 */
# endif
# undef TTYS3_DEV /* No ttyS3 */
# endif
# else
# ifdef CONFIG_16550_UART1
# define TTYS1_DEV g_uart1port /* UART2=ttyS0;UART1=ttyS1 */
# ifdef CONFIG_16550_UART3
# define TTYS2_DEV g_uart3port /* UART2=ttyS0;UART1=ttyS1;UART3=ttyS2 */
# else
# undef TTYS2_DEV /* UART2=ttyS0;UART1=ttyS1;No ttyS2;No ttyS3 */
# endif
# undef TTYS3_DEV /* No ttyS3 */
# else
# ifdef CONFIG_16550_UART3
# define TTYS1_DEV g_uart3port /* UART2=ttyS0;UART3=ttyS1;No ttyS3 */
# else
# undef TTYS1_DEV /* UART2=ttyS0;No ttyS1;No ttyS2;No ttyS3 */
# endif
# undef TTYS2_DEV /* No ttyS2 */
# undef TTYS3_DEV /* No ttyS3 */
# endif
# endif
# elif defined(CONFIG_16550_UART3_SERIAL_CONSOLE)
# define CONSOLE_DEV g_uart3port /* UART3=console */
# define TTYS0_DEV g_uart3port /* UART3=ttyS0 */
# ifdef CONFIG_16550_UART0
# define TTYS1_DEV g_uart0port /* UART3=ttyS0;UART0=ttyS1 */
# ifdef CONFIG_16550_UART1
# define TTYS2_DEV g_uart1port /* UART3=ttyS0;UART0=ttyS1;UART1=ttyS2 */
# ifdef CONFIG_16550_UART2
# define TTYS3_DEV g_uart2port /* UART3=ttyS0;UART0=ttyS1;UART1=ttyS2;UART2=ttyS3 */
# else
# undef TTYS3_DEV /* UART3=ttyS0;UART0=ttyS1;UART1=ttyS;No ttyS3 */
# endif
# else
# ifdef CONFIG_16550_UART2
# define TTYS2_DEV g_uart2port /* UART3=ttyS0;UART0=ttyS1;UART2=ttys2;No ttyS3 */
# else
# undef TTYS2_DEV /* UART3=ttyS0;UART0=ttyS1;No ttyS2;No ttyS3 */
# endif
# undef TTYS3_DEV /* No ttyS3 */
# endif
# else
# ifdef CONFIG_16550_UART1
# define TTYS1_DEV g_uart1port /* UART3=ttyS0;UART1=ttyS1 */
# ifdef CONFIG_16550_UART2
# define TTYS2_DEV g_uart2port /* UART3=ttyS0;UART1=ttyS1;UART2=ttyS2;No ttyS3 */
# else
# undef TTYS2_DEV /* UART3=ttyS0;UART1=ttyS1;No ttyS2;No ttyS3 */
# endif
# undef TTYS3_DEV /* No ttyS3 */
# else
# ifdef CONFIG_16550_UART2
# define TTYS1_DEV g_uart2port /* UART3=ttyS0;UART2=ttyS1;No ttyS3;No ttyS3 */
# undef TTYS3_DEV /* UART3=ttyS0;UART2=ttyS1;No ttyS2;No ttyS3 */
# else
# undef TTYS1_DEV /* UART3=ttyS0;No ttyS1;No ttyS2;No ttyS3 */
# endif
# undef TTYS2_DEV /* No ttyS2 */
# undef TTYS3_DEV /* No ttyS3 */
# endif
# endif
# endif
#endif /* CONFIG_16550_SERIAL_DISABLE_REORDERING */
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: u16550_serialin
****************************************************************************/
static inline uart_datawidth_t u16550_serialin(FAR struct u16550_s *priv,
int offset)
{
#ifdef CONFIG_SERIAL_UART_ARCH_MMIO
return *((FAR volatile uart_addrwidth_t *)priv->uartbase + offset);
#else
return uart_getreg(priv->uartbase, offset);
#endif
}
/****************************************************************************
* Name: u16550_serialout
****************************************************************************/
static inline void u16550_serialout(FAR struct u16550_s *priv, int offset,
uart_datawidth_t value)
{
#ifdef CONFIG_SERIAL_UART_ARCH_MMIO
*((FAR volatile uart_addrwidth_t *)priv->uartbase + offset) = value;
#else
uart_putreg(priv->uartbase, offset, value);
#endif
}
/****************************************************************************
* Name: u16550_disableuartint
****************************************************************************/
static inline void u16550_disableuartint(FAR struct u16550_s *priv,
FAR uart_datawidth_t *ier)
{
if (ier)
{
*ier = priv->ier & UART_IER_ALLIE;
}
priv->ier &= ~UART_IER_ALLIE;
u16550_serialout(priv, UART_IER_OFFSET, priv->ier);
}
/****************************************************************************
* Name: u16550_restoreuartint
****************************************************************************/
static inline void u16550_restoreuartint(FAR struct u16550_s *priv,
uint32_t ier)
{
priv->ier |= ier & UART_IER_ALLIE;
u16550_serialout(priv, UART_IER_OFFSET, priv->ier);
}
/****************************************************************************
* Name: u16550_enablebreaks
****************************************************************************/
static inline void u16550_enablebreaks(FAR struct u16550_s *priv,
bool enable)
{
uint32_t lcr = u16550_serialin(priv, UART_LCR_OFFSET);
if (enable)
{
lcr |= UART_LCR_BRK;
}
else
{
lcr &= ~UART_LCR_BRK;
}
u16550_serialout(priv, UART_LCR_OFFSET, lcr);
}
/****************************************************************************
* Name: u16550_divisor
*
* Description:
* Select a divider to produce the BAUD from the UART_CLK.
*
* BAUD = UART_CLK / (16 * DL), or
* DIV = UART_CLK / BAUD / 16
*
* Ignoring the fractional divider for now.
*
****************************************************************************/
#ifndef CONFIG_16550_SUPRESS_CONFIG
static inline uint32_t u16550_divisor(FAR struct u16550_s *priv)
{
return (priv->uartclk + (priv->baud << 3)) / (priv->baud << 4);
}
#endif
/****************************************************************************
* Name: u16550_setup
*
* Description:
* Configure the UART baud, bits, parity, fifos, etc. This
* method is called the first time that the serial port is
* opened.
*
****************************************************************************/
static int u16550_setup(FAR struct uart_dev_s *dev)
{
#ifndef CONFIG_16550_SUPRESS_CONFIG
FAR struct u16550_s *priv = (FAR struct u16550_s *)dev->priv;
uint16_t div;
uint32_t lcr;
#if defined(CONFIG_SERIAL_IFLOWCONTROL) || defined(CONFIG_SERIAL_OFLOWCONTROL)
uint32_t mcr;
#endif
/* Clear fifos */
u16550_serialout(priv, UART_FCR_OFFSET,
(UART_FCR_RXRST | UART_FCR_TXRST));
/* Set trigger */
u16550_serialout(priv, UART_FCR_OFFSET,
(UART_FCR_FIFOEN | UART_FCR_RXTRIGGER_8));
/* Set up the IER */
priv->ier = u16550_serialin(priv, UART_IER_OFFSET);
/* Set up the LCR */
lcr = 0;
switch (priv->bits)
{
case 5 :
lcr |= UART_LCR_WLS_5BIT;
break;
case 6 :
lcr |= UART_LCR_WLS_6BIT;
break;
case 7 :
lcr |= UART_LCR_WLS_7BIT;
break;
default:
case 8 :
lcr |= UART_LCR_WLS_8BIT;
break;
}
if (priv->stopbits2)
{
lcr |= UART_LCR_STB;
}
if (priv->parity == 1)
{
lcr |= UART_LCR_PEN;
}
else if (priv->parity == 2)
{
lcr |= (UART_LCR_PEN | UART_LCR_EPS);
}
/* Enter DLAB=1 */
u16550_serialout(priv, UART_LCR_OFFSET, (lcr | UART_LCR_DLAB));
/* Set the BAUD divisor */
div = u16550_divisor(priv);
u16550_serialout(priv, UART_DLM_OFFSET, div >> 8);
u16550_serialout(priv, UART_DLL_OFFSET, div & 0xff);
/* Clear DLAB */
u16550_serialout(priv, UART_LCR_OFFSET, lcr);
/* Configure the FIFOs */
u16550_serialout(priv, UART_FCR_OFFSET,
(UART_FCR_RXTRIGGER_8 | UART_FCR_TXRST | UART_FCR_RXRST |
UART_FCR_FIFOEN));
/* Set up the auto flow control */
#if defined(CONFIG_SERIAL_IFLOWCONTROL) || defined(CONFIG_SERIAL_OFLOWCONTROL)
mcr = u16550_serialin(priv, UART_MCR_OFFSET);
if (priv->flow)
{
mcr |= UART_MCR_AFCE;
}
else
{
mcr &= ~UART_MCR_AFCE;
}
mcr |= UART_MCR_RTS;
u16550_serialout(priv, UART_MCR_OFFSET, mcr);
#endif /* defined(CONFIG_SERIAL_IFLOWCONTROL) || defined(CONFIG_SERIAL_OFLOWCONTROL) */
#endif
return OK;
}
/****************************************************************************
* Name: u16550_shutdown
*
* Description:
* Disable the UART. This method is called when the serial
* port is closed
*
****************************************************************************/
static void u16550_shutdown(struct uart_dev_s *dev)
{
FAR struct u16550_s *priv = (FAR struct u16550_s *)dev->priv;
u16550_disableuartint(priv, NULL);
}
/****************************************************************************
* Name: u16550_attach
*
* Description:
* Configure the UART to operation in interrupt driven mode. This method
* is called when the serial port is opened. Normally, this is just after
* the setup() method is called, however, the serial console may operate in
* a non-interrupt driven mode during the boot phase.
*
* RX and TX interrupts are not enabled when by the attach method (unless
* the hardware supports multiple levels of interrupt enabling). The RX
* and TX interrupts are not enabled until the txint() and rxint() methods
* are called.
*
****************************************************************************/
static int u16550_attach(struct uart_dev_s *dev)
{
FAR struct u16550_s *priv = (FAR struct u16550_s *)dev->priv;
int ret;
/* Attach and enable the IRQ */
ret = irq_attach(priv->irq, u16550_interrupt, dev);
#ifndef CONFIG_ARCH_NOINTC
if (ret == OK)
{
/* Enable the interrupt (RX and TX interrupts are still disabled
* in the UART
*/
up_enable_irq(priv->irq);
}
#endif
return ret;
}
/****************************************************************************
* Name: u16550_detach
*
* Description:
* Detach UART interrupts. This method is called when the serial port is
* closed normally just before the shutdown method is called.
* The exception is the serial console which is never shutdown.
*
****************************************************************************/
static void u16550_detach(FAR struct uart_dev_s *dev)
{
FAR struct u16550_s *priv = (FAR struct u16550_s *)dev->priv;
up_disable_irq(priv->irq);
irq_detach(priv->irq);
}
/****************************************************************************
* Name: u16550_interrupt
*
* Description:
* This is the UART interrupt handler. It will be invoked when an
* interrupt received on the 'irq' It should call uart_transmitchars or
* uart_receivechar to perform the appropriate data transfers. The
* interrupt handling logic must be able to map the 'irq' number into the
* appropriate u16550_s structure in order to call these functions.
*
****************************************************************************/
static int u16550_interrupt(int irq, FAR void *context, FAR void *arg)
{
FAR struct uart_dev_s *dev = (struct uart_dev_s *)arg;
FAR struct u16550_s *priv;
uint32_t status;
int passes;
DEBUGASSERT(dev != NULL && dev->priv != NULL);
priv = (FAR struct u16550_s *)dev->priv;
/* Loop until there are no characters to be transferred or,
* until we have been looping for a long time.
*/
for (passes = 0; passes < 256; passes++)
{
/* Get the current UART status and check for loop
* termination conditions
*/
status = u16550_serialin(priv, UART_IIR_OFFSET);
/* The UART_IIR_INTSTATUS bit should be zero if there are pending
* interrupts
*/
if ((status & UART_IIR_INTSTATUS) != 0)
{
/* Break out of the loop when there is no longer a
* pending interrupt
*/
break;
}
/* Handle the interrupt by its interrupt ID field */
switch (status & UART_IIR_INTID_MASK)
{
/* Handle incoming, receive bytes (with or without timeout) */
case UART_IIR_INTID_RDA:
case UART_IIR_INTID_CTI:
{
uart_recvchars(dev);
break;
}
/* Handle outgoing, transmit bytes */
case UART_IIR_INTID_THRE:
{
uart_xmitchars(dev);
break;
}
/* Just clear modem status interrupts (UART1 only) */
case UART_IIR_INTID_MSI:
{
/* Read the modem status register (MSR) to clear */
status = u16550_serialin(priv, UART_MSR_OFFSET);
sinfo("MSR: %02x\n", status);
break;
}
/* Just clear any line status interrupts */
case UART_IIR_INTID_RLS:
{
/* Read the line status register (LSR) to clear */
status = u16550_serialin(priv, UART_LSR_OFFSET);
sinfo("LSR: %02x\n", status);
break;
}
/* There should be no other values */
default:
{
serr("ERROR: Unexpected IIR: %02x\n", status);
break;
}
}
}
return OK;
}
/****************************************************************************
* Name: u16550_ioctl
*
* Description:
* All ioctl calls will be routed through this method
*
****************************************************************************/
static int u16550_ioctl(struct file *filep, int cmd, unsigned long arg)
{
FAR struct inode *inode = filep->f_inode;
FAR struct uart_dev_s *dev = inode->i_private;
FAR struct u16550_s *priv = (FAR struct u16550_s *)dev->priv;
int ret;
#ifdef CONFIG_SERIAL_UART_ARCH_IOCTL
ret = uart_ioctl(filep, cmd, arg);
if (ret != -ENOTTY)
{
return ret;
}
#else
ret = OK;
#endif
switch (cmd)
{
#ifdef CONFIG_SERIAL_TIOCSERGSTRUCT
case TIOCSERGSTRUCT:
{
FAR struct u16550_s *user = (FAR struct u16550_s *)arg;
if (!user)
{
ret = -EINVAL;
}
else
{
memcpy(user, dev, sizeof(struct u16550_s));
}
}
break;
#endif
case TIOCSBRK: /* BSD compatibility: Turn break on, unconditionally */
{
irqstate_t flags = enter_critical_section();
u16550_enablebreaks(priv, true);
leave_critical_section(flags);
}
break;
case TIOCCBRK: /* BSD compatibility: Turn break off, unconditionally */
{
irqstate_t flags;
flags = enter_critical_section();
u16550_enablebreaks(priv, false);
leave_critical_section(flags);
}
break;
#if defined(CONFIG_SERIAL_TERMIOS) && !defined(CONFIG_16550_SUPRESS_CONFIG)
case TCGETS:
{
FAR struct termios *termiosp = (FAR struct termios *)arg;
irqstate_t flags;
if (!termiosp)
{
ret = -EINVAL;
break;
}
flags = enter_critical_section();
cfsetispeed(termiosp, priv->baud);
termiosp->c_cflag = ((priv->parity != 0) ? PARENB : 0) |
((priv->parity == 1) ? PARODD : 0);
termiosp->c_cflag |= (priv->stopbits2) ? CSTOPB : 0;
#if defined(CONFIG_SERIAL_IFLOWCONTROL) || defined(CONFIG_SERIAL_OFLOWCONTROL)
termiosp->c_cflag |= priv->flow ? CRTSCTS : 0;
#endif
switch (priv->bits)
{
case 5:
termiosp->c_cflag |= CS5;
break;
case 6:
termiosp->c_cflag |= CS6;
break;
case 7:
termiosp->c_cflag |= CS7;
break;
case 8:
default:
termiosp->c_cflag |= CS8;
break;
}
leave_critical_section(flags);
}
break;
case TCSETS:
{
FAR struct termios *termiosp = (FAR struct termios *)arg;
irqstate_t flags;
if (!termiosp)
{
ret = -EINVAL;
break;
}
flags = enter_critical_section();
switch (termiosp->c_cflag & CSIZE)
{
case CS5:
priv->bits = 5;
break;
case CS6:
priv->bits = 6;
break;
case CS7:
priv->bits = 7;
break;
case CS8:
default:
priv->bits = 8;
break;
}
if ((termiosp->c_cflag & PARENB) != 0)
{
priv->parity = (termiosp->c_cflag & PARODD) ? 1 : 2;
}
else
{
priv->parity = 0;
}
priv->baud = cfgetispeed(termiosp);
priv->stopbits2 = (termiosp->c_cflag & CSTOPB) != 0;
#if defined(CONFIG_SERIAL_IFLOWCONTROL) || defined(CONFIG_SERIAL_OFLOWCONTROL)
priv->flow = (termiosp->c_cflag & CRTSCTS) != 0;
#endif
u16550_setup(dev);
leave_critical_section(flags);
}
break;
#endif
default:
ret = -ENOTTY;
break;
}
return ret;
}
/****************************************************************************
* Name: u16550_receive
*
* Description:
* Called (usually) from the interrupt level to receive one
* character from the UART. Error bits associated with the
* receipt are provided in the return 'status'.
*
****************************************************************************/
static int u16550_receive(struct uart_dev_s *dev, unsigned int *status)
{
FAR struct u16550_s *priv = (FAR struct u16550_s *)dev->priv;
uint32_t rbr;
*status = u16550_serialin(priv, UART_LSR_OFFSET);
rbr = u16550_serialin(priv, UART_RBR_OFFSET);
return rbr;
}
/****************************************************************************
* Name: u16550_rxint
*
* Description:
* Call to enable or disable RX interrupts
*
****************************************************************************/
static void u16550_rxint(struct uart_dev_s *dev, bool enable)
{
FAR struct u16550_s *priv = (FAR struct u16550_s *)dev->priv;
if (enable)
{
priv->ier |= UART_IER_ERBFI;
}
else
{
priv->ier &= ~UART_IER_ERBFI;
}
u16550_serialout(priv, UART_IER_OFFSET, priv->ier);
}
/****************************************************************************
* Name: u16550_rxavailable
*
* Description:
* Return true if the receive fifo is not empty
*
****************************************************************************/
static bool u16550_rxavailable(struct uart_dev_s *dev)
{
FAR struct u16550_s *priv = (FAR struct u16550_s *)dev->priv;
return ((u16550_serialin(priv, UART_LSR_OFFSET) & UART_LSR_DR) != 0);
}
/****************************************************************************
* Name: u16550_dma*
*
* Description:
* Stubbed out DMA-related methods
*
****************************************************************************/
#ifdef CONFIG_SERIAL_IFLOWCONTROL
static bool u16550_rxflowcontrol(struct uart_dev_s *dev,
unsigned int nbuffered, bool upper)
{
#ifndef CONFIG_16550_SUPRESS_CONFIG
FAR struct u16550_s *priv = (FAR struct u16550_s *)dev->priv;
if (priv->flow)
{
/* Disable Rx interrupt to prevent more data being from
* peripheral if the RX buffer is near full. When hardware
* RTS is enabled, this will prevent more data from coming
* in. Otherwise, enable Rx interrupt to make sure that more
* input is received.
*/
u16550_rxint(dev, !upper);
return true;
}
#endif
return false;
}
#endif
/****************************************************************************
* Name: u16550_dma*
*
* Description:
* Stub functions used when serial DMA is enabled.
*
****************************************************************************/
#ifdef CONFIG_SERIAL_TXDMA
static void u16550_dmasend(FAR struct uart_dev_s *dev)
{
}
#endif
#ifdef CONFIG_SERIAL_RXDMA
static void u16550_dmareceive(FAR struct uart_dev_s *dev)
{
}
static void u16550_dmarxfree(FAR struct uart_dev_s *dev)
{
}
#endif
#ifdef CONFIG_SERIAL_TXDMA
static void u16550_dmatxavail(FAR struct uart_dev_s *dev)
{
}
#endif
/****************************************************************************
* Name: u16550_send
*
* Description:
* This method will send one byte on the UART
*
****************************************************************************/
static void u16550_send(struct uart_dev_s *dev, int ch)
{
FAR struct u16550_s *priv = (FAR struct u16550_s *)dev->priv;
u16550_serialout(priv, UART_THR_OFFSET, (uart_datawidth_t)ch);
}
/****************************************************************************
* Name: u16550_txint
*
* Description:
* Call to enable or disable TX interrupts
*
****************************************************************************/
static void u16550_txint(struct uart_dev_s *dev, bool enable)
{
FAR struct u16550_s *priv = (FAR struct u16550_s *)dev->priv;
irqstate_t flags;
flags = enter_critical_section();
if (enable)
{
priv->ier |= UART_IER_ETBEI;
u16550_serialout(priv, UART_IER_OFFSET, priv->ier);
/* Fake a TX interrupt here by just calling uart_xmitchars() with
* interrupts disabled (note this may recurse).
*/
uart_xmitchars(dev);
}
else
{
priv->ier &= ~UART_IER_ETBEI;
u16550_serialout(priv, UART_IER_OFFSET, priv->ier);
}
leave_critical_section(flags);
}
/****************************************************************************
* Name: u16550_txready
*
* Description:
* Return true if the tranmsit fifo is not full
*
****************************************************************************/
static bool u16550_txready(struct uart_dev_s *dev)
{
FAR struct u16550_s *priv = (FAR struct u16550_s *)dev->priv;
return ((u16550_serialin(priv, UART_LSR_OFFSET) & UART_LSR_THRE) != 0);
}
/****************************************************************************
* Name: u16550_txempty
*
* Description:
* Return true if the transmit fifo is empty
*
****************************************************************************/
static bool u16550_txempty(struct uart_dev_s *dev)
{
FAR struct u16550_s *priv = (FAR struct u16550_s *)dev->priv;
return ((u16550_serialin(priv, UART_LSR_OFFSET) & UART_LSR_TEMT) != 0);
}
/****************************************************************************
* Name: u16550_putc
*
* Description:
* Write one character to the UART (polled)
*
****************************************************************************/
#ifdef HAVE_16550_CONSOLE
static void u16550_putc(FAR struct u16550_s *priv, int ch)
{
while ((u16550_serialin(priv, UART_LSR_OFFSET) & UART_LSR_THRE) == 0);
u16550_serialout(priv, UART_THR_OFFSET, (uart_datawidth_t)ch);
}
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: up_earlyserialinit
*
* Description:
* Performs the low level UART initialization early in debug so that the
* serial console will be available during bootup. This must be called
* before uart_serialinit.
*
* NOTE: Configuration of the CONSOLE UART was performed by uart_lowsetup()
* very early in the boot sequence.
*
****************************************************************************/
void up_earlyserialinit(void)
{
/* Configuration whichever one is the console */
#ifdef CONSOLE_DEV
CONSOLE_DEV.isconsole = true;
#ifndef CONFIG_16550_SUPRESS_INITIAL_CONFIG
u16550_setup(&CONSOLE_DEV);
#endif
#endif
}
/****************************************************************************
* Name: up_serialinit
*
* Description:
* Register serial console and serial ports. This assumes that
* up_earlyserialinit was called previously.
*
****************************************************************************/
void up_serialinit(void)
{
#ifdef CONSOLE_DEV
uart_register("/dev/console", &CONSOLE_DEV);
#endif
#ifdef TTYS0_DEV
uart_register("/dev/ttyS0", &TTYS0_DEV);
#endif
#ifdef TTYS1_DEV
uart_register("/dev/ttyS1", &TTYS1_DEV);
#endif
#ifdef TTYS2_DEV
uart_register("/dev/ttyS2", &TTYS2_DEV);
#endif
#ifdef TTYS3_DEV
uart_register("/dev/ttyS3", &TTYS3_DEV);
#endif
}
/****************************************************************************
* Name: up_putc
*
* Description:
* Provide priority, low-level access to support OS debug writes
*
****************************************************************************/
#ifdef HAVE_16550_CONSOLE
int up_putc(int ch)
{
FAR struct u16550_s *priv = (FAR struct u16550_s *)CONSOLE_DEV.priv;
uart_datawidth_t ier;
u16550_disableuartint(priv, &ier);
/* Check for LF */
if (ch == '\n')
{
/* Add CR */
u16550_putc(priv, '\r');
}
u16550_putc(priv, ch);
u16550_restoreuartint(priv, ier);
return ch;
}
#endif
#endif /* CONFIG_16550_UART */
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