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px4-firmware/nuttx/drivers/serial/uart_16550.c

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/****************************************************************************
* drivers/serial/uart_16550.c
* Serial driver for 16550 UART
*
* Copyright (C) 2011 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <unistd.h>
#include <semaphore.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
#ifndef CONFIG_SUPPRESS_SERIAL_INTS
uart_datawidth_t ier; /* Saved IER value */
uint8_t irq; /* IRQ associated with this UART */
#endif
#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 */
#endif
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static int u16550_setup(struct uart_dev_s *dev);
static void u16550_shutdown(struct uart_dev_s *dev);
static int u16550_attach(struct uart_dev_s *dev);
static void u16550_detach(struct uart_dev_s *dev);
#ifndef CONFIG_SUPPRESS_SERIAL_INTS
static int u16550_interrupt(int irq, void *context);
#endif
static int u16550_ioctl(struct file *filep, int cmd, unsigned long arg);
static int u16550_receive(struct uart_dev_s *dev, uint32_t *status);
static void u16550_rxint(struct uart_dev_s *dev, bool enable);
static bool u16550_rxavailable(struct uart_dev_s *dev);
static void u16550_send(struct uart_dev_s *dev, int ch);
static void u16550_txint(struct uart_dev_s *dev, bool enable);
static bool u16550_txready(struct uart_dev_s *dev);
static bool u16550_txempty(struct uart_dev_s *dev);
/****************************************************************************
* Private Variables
****************************************************************************/
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,
.send = u16550_send,
.txint = u16550_txint,
.txready = u16550_txready,
.txempty = u16550_txempty,
};
/* I/O buffers */
#ifdef CONFIG_16550_UART0
static char g_uart0rxbuffer[CONFIG_UART0_RXBUFSIZE];
static char g_uart0txbuffer[CONFIG_UART0_TXBUFSIZE];
#endif
#ifdef CONFIG_16550_UART1
static char g_uart1rxbuffer[CONFIG_UART1_RXBUFSIZE];
static char g_uart1txbuffer[CONFIG_UART1_TXBUFSIZE];
#endif
#ifdef CONFIG_16550_UART2
static char g_uart2rxbuffer[CONFIG_UART1_RXBUFSIZE];
static char g_uart2txbuffer[CONFIG_UART1_TXBUFSIZE];
#endif
#ifdef CONFIG_16550_UART3
static char g_uart3rxbuffer[CONFIG_UART1_RXBUFSIZE];
static char g_uart3txbuffer[CONFIG_UART1_TXBUFSIZE];
#endif
/* This describes the state of the LPC17xx uart0 port. */
#ifdef CONFIG_16550_UART0
static struct u16550_s g_uart0priv =
{
.uartbase = CONFIG_16550_UART0_BASE,
#ifndef CONFIG_16550_SUPRESS_CONFIG
.baud = CONFIG_UART0_BAUD,
.uartclk = CONFIG_16550_UART0_CLOCK,
#endif
#ifndef CONFIG_SUPPRESS_SERIAL_INTS
.irq = CONFIG_16550_UART0_IRQ,
#endif
#ifndef CONFIG_16550_SUPRESS_CONFIG
.parity = CONFIG_UART0_PARITY,
.bits = CONFIG_UART0_BITS,
.stopbits2 = CONFIG_UART0_2STOP,
#endif
};
static uart_dev_t g_uart0port =
{
.recv =
{
.size = CONFIG_UART0_RXBUFSIZE,
.buffer = g_uart0rxbuffer,
},
.xmit =
{
.size = CONFIG_UART0_TXBUFSIZE,
.buffer = g_uart0txbuffer,
},
.ops = &g_uart_ops,
.priv = &g_uart0priv,
};
#endif
/* This describes the state of the LPC17xx uart1 port. */
#ifdef CONFIG_16550_UART1
static struct u16550_s g_uart1priv =
{
.uartbase = CONFIG_16550_UART1_BASE,
#ifndef CONFIG_16550_SUPRESS_CONFIG
.baud = CONFIG_UART1_BAUD,
.uartclk = CONFIG_16550_UART1_CLOCK,
#endif
#ifndef CONFIG_SUPPRESS_SERIAL_INTS
.irq = CONFIG_16550_UART1_IRQ,
#endif
#ifndef CONFIG_16550_SUPRESS_CONFIG
.parity = CONFIG_UART1_PARITY,
.bits = CONFIG_UART1_BITS,
.stopbits2 = CONFIG_UART1_2STOP,
#endif
};
static uart_dev_t g_uart1port =
{
.recv =
{
.size = CONFIG_UART1_RXBUFSIZE,
.buffer = g_uart1rxbuffer,
},
.xmit =
{
.size = CONFIG_UART1_TXBUFSIZE,
.buffer = g_uart1txbuffer,
},
.ops = &g_uart_ops,
.priv = &g_uart1priv,
};
#endif
/* This describes the state of the LPC17xx uart1 port. */
#ifdef CONFIG_16550_UART2
static struct u16550_s g_uart2priv =
{
.uartbase = CONFIG_16550_UART2_BASE,
#ifndef CONFIG_16550_SUPRESS_CONFIG
.baud = CONFIG_UART2_BAUD,
.uartclk = CONFIG_16550_UART2_CLOCK,
#endif
#ifndef CONFIG_SUPPRESS_SERIAL_INTS
.irq = CONFIG_16550_UART2_IRQ,
#endif
#ifndef CONFIG_16550_SUPRESS_CONFIG
.parity = CONFIG_UART2_PARITY,
.bits = CONFIG_UART2_BITS,
.stopbits2 = CONFIG_UART2_2STOP,
#endif
};
static uart_dev_t g_uart2port =
{
.recv =
{
.size = CONFIG_UART2_RXBUFSIZE,
.buffer = g_uart2rxbuffer,
},
.xmit =
{
.size = CONFIG_UART2_TXBUFSIZE,
.buffer = g_uart2txbuffer,
},
.ops = &g_uart_ops,
.priv = &g_uart2priv,
};
#endif
/* This describes the state of the LPC17xx uart1 port. */
#ifdef CONFIG_16550_UART3
static struct u16550_s g_uart3priv =
{
.uartbase = CONFIG_16550_UART3_BASE,
#ifndef CONFIG_16550_SUPRESS_CONFIG
.baud = CONFIG_UART3_BAUD,
.uartclk = CONFIG_16550_UART3_CLOCK,
#endif
#ifndef CONFIG_SUPPRESS_SERIAL_INTS
.irq = CONFIG_16550_UART3_IRQ,
#endif
#ifndef CONFIG_16550_SUPRESS_CONFIG
.parity = CONFIG_UART3_PARITY,
.bits = CONFIG_UART3_BITS,
.stopbits2 = CONFIG_UART3_2STOP,
#endif
};
static uart_dev_t g_uart3port =
{
.recv =
{
.size = CONFIG_UART3_RXBUFSIZE,
.buffer = g_uart3rxbuffer,
},
.xmit =
{
.size = CONFIG_UART3_TXBUFSIZE,
.buffer = g_uart3txbuffer,
},
.ops = &g_uart_ops,
.priv = &g_uart3priv,
};
#endif
/* Which UART with be tty0/console and which tty1? tty2? tty3? */
#if defined(CONFIG_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_UART1_SERIAL_CONSOLE)
# define CONSOLE_DEV g_uart1port /* UART1=console */
# define TTYS0_DEV g_uart1port /* UART1=ttyS0 */
# ifdef CONFIG_16550_UART
# 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_UART2_SERIAL_CONSOLE)
# define CONSOLE_DEV g_uart2port /* UART2=console */
# define TTYS0_DEV g_uart2port /* UART2=ttyS0 */
# ifdef CONFIG_16550_UART
# 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_UART3_SERIAL_CONSOLE)
# define CONSOLE_DEV g_uart3port /* UART3=console */
# define TTYS0_DEV g_uart3port /* UART3=ttyS0 */
# ifdef CONFIG_16550_UART
# 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
/************************************************************************************
* Inline Functions
************************************************************************************/
/****************************************************************************
* Name: u16550_serialin
****************************************************************************/
static inline uart_datawidth_t u16550_serialin(struct u16550_s *priv, int offset)
{
return uart_getreg(priv->uartbase, offset);
}
/****************************************************************************
* Name: u16550_serialout
****************************************************************************/
static inline void u16550_serialout(struct u16550_s *priv, int offset, uart_datawidth_t value)
{
uart_putreg(priv->uartbase, offset, value);
}
/****************************************************************************
* Name: u16550_disableuartint
****************************************************************************/
#ifndef CONFIG_SUPPRESS_SERIAL_INTS
static inline void u16550_disableuartint(struct u16550_s *priv, 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);
}
#else
# define u16550_disableuartint(priv,ier)
#endif
/****************************************************************************
* Name: u16550_restoreuartint
****************************************************************************/
#ifndef CONFIG_SUPPRESS_SERIAL_INTS
static inline void u16550_restoreuartint(struct u16550_s *priv, uint32_t ier)
{
priv->ier |= ier & UART_IER_ALLIE;
u16550_serialout(priv, UART_IER_OFFSET, priv->ier);
}
#else
# define u16550_restoreuartint(priv,ier)
#endif
/****************************************************************************
* Name: u16550_enablebreaks
****************************************************************************/
static inline void u16550_enablebreaks(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
*
* Descrption:
* 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(struct u16550_s *priv)
{
return (priv->uartclk + (priv->baud << 3)) / (priv->baud << 4);
}
#endif
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* 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(struct uart_dev_s *dev)
{
#ifndef CONFIG_16550_SUPRESS_CONFIG
struct u16550_s *priv = (struct u16550_s*)dev->priv;
uint16_t div;
uint32_t lcr;
/* 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 */
#ifndef CONFIG_SUPPRESS_SERIAL_INTS
priv->ier = u16550_serialin(priv, UART_IER_OFFSET);
#endif
/* Set up the LCR */
lcr = 0;
switch (priv->bits)
{
case 5 :
lcr |= UART_LCR_WLS_7BIT;
break;
case 6 :
lcr |= UART_LCR_WLS_7BIT;
break;
case 7 :
lcr |= UART_LCR_WLS_7BIT;
break;
default:
case 8 :
lcr |= UART_LCR_WLS_7BIT;
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));
#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)
{
struct u16550_s *priv = (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
* 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)
{
#ifndef CONFIG_SUPPRESS_SERIAL_INTS
struct u16550_s *priv = (struct u16550_s*)dev->priv;
int ret;
/* Attach and enable the IRQ */
ret = irq_attach(priv->irq, u16550_interrupt);
#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;
#else
return OK;
#endif
}
/****************************************************************************
* 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(struct uart_dev_s *dev)
{
#ifndef CONFIG_SUPPRESS_SERIAL_INTS
struct u16550_s *priv = (struct u16550_s*)dev->priv;
#ifndef CONFIG_ARCH_NOINTC
up_disable_irq(priv->irq);
#endif
irq_detach(priv->irq);
#endif
}
/****************************************************************************
* 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.
*
****************************************************************************/
#ifndef CONFIG_SUPPRESS_SERIAL_INTS
static int u16550_interrupt(int irq, void *context)
{
struct uart_dev_s *dev = NULL;
struct u16550_s *priv;
uint32_t status;
int passes;
#ifdef CONFIG_16550_UART0
if (g_uart0priv.irq == irq)
{
dev = &g_uart0port;
}
else
#endif
#ifdef CONFIG_16550_UART1
if (g_uart1priv.irq == irq)
{
dev = &g_uart1port;
}
else
#endif
#ifdef CONFIG_16550_UART2
if (g_uart2priv.irq == irq)
{
dev = &g_uart2port;
}
else
#endif
#ifdef CONFIG_16550_UART3
if (g_uart3priv.irq == irq)
{
dev = &g_uart3port;
}
#endif
ASSERT(dev != NULL);
priv = (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);
vdbg("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);
vdbg("LSR: %02x\n", status);
break;
}
/* There should be no other values */
default:
{
dbg("Unexpected IIR: %02x\n", status);
break;
}
}
}
return OK;
}
#endif
/****************************************************************************
* 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)
{
struct inode *inode = filep->f_inode;
struct uart_dev_s *dev = inode->i_private;
struct u16550_s *priv = (struct u16550_s*)dev->priv;
int ret = OK;
switch (cmd)
{
case TIOCSERGSTRUCT:
{
struct u16550_s *user = (struct u16550_s*)arg;
if (!user)
{
set_errno(EINVAL);
ret = ERROR;
}
else
{
memcpy(user, dev, sizeof(struct u16550_s));
}
}
break;
case TIOCSBRK: /* BSD compatibility: Turn break on, unconditionally */
{
irqstate_t flags = irqsave();
u16550_enablebreaks(priv, true);
irqrestore(flags);
}
break;
case TIOCCBRK: /* BSD compatibility: Turn break off, unconditionally */
{
irqstate_t flags;
flags = irqsave();
u16550_enablebreaks(priv, false);
irqrestore(flags);
}
break;
default:
set_errno(ENOTTY);
ret = ERROR;
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, uint32_t *status)
{
struct u16550_s *priv = (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)
{
#ifndef CONFIG_SUPPRESS_SERIAL_INTS
struct u16550_s *priv = (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);
#endif
}
/****************************************************************************
* Name: u16550_rxavailable
*
* Description:
* Return true if the receive fifo is not empty
*
****************************************************************************/
static bool u16550_rxavailable(struct uart_dev_s *dev)
{
struct u16550_s *priv = (struct u16550_s*)dev->priv;
return ((u16550_serialin(priv, UART_LSR_OFFSET) & UART_LSR_DR) != 0);
}
/****************************************************************************
* Name: u16550_send
*
* Description:
* This method will send one byte on the UART
*
****************************************************************************/
static void u16550_send(struct uart_dev_s *dev, int ch)
{
struct u16550_s *priv = (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)
{
#ifndef CONFIG_SUPPRESS_SERIAL_INTS
struct u16550_s *priv = (struct u16550_s*)dev->priv;
irqstate_t flags;
flags = irqsave();
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);
}
irqrestore(flags);
#endif
}
/****************************************************************************
* Name: u16550_txready
*
* Description:
* Return true if the tranmsit fifo is not full
*
****************************************************************************/
static bool u16550_txready(struct uart_dev_s *dev)
{
struct u16550_s *priv = (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)
{
struct u16550_s *priv = (struct u16550_s*)dev->priv;
return ((u16550_serialin(priv, UART_LSR_OFFSET) & UART_LSR_THRE) != 0);
}
/****************************************************************************
* Name: u16550_putc
*
* Description:
* Write one character to the UART (polled)
*
****************************************************************************/
static void u16550_putc(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);
}
/****************************************************************************
* Public Funtions
****************************************************************************/
/****************************************************************************
* 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)
{
/* Configure all UARTs (except the CONSOLE UART) and disable interrupts */
#ifdef CONFIG_16550_UART0
u16550_disableuartint(&g_uart0priv, NULL);
#endif
#ifdef CONFIG_16550_UART1
u16550_disableuartint(&g_uart1priv, NULL);
#endif
#ifdef CONFIG_16550_UART2
u16550_disableuartint(&g_uart2priv, NULL);
#endif
#ifdef CONFIG_16550_UART3
u16550_disableuartint(&g_uart3priv, NULL);
#endif
/* Configuration whichever one is the console */
#ifdef CONSOLE_DEV
CONSOLE_DEV.isconsole = true;
u16550_setup(&CONSOLE_DEV);
#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
(void)uart_register("/dev/console", &CONSOLE_DEV);
#endif
#ifdef TTYS0_DEV
(void)uart_register("/dev/ttyS0", &TTYS0_DEV);
#endif
#ifdef TTYS1_DEV
(void)uart_register("/dev/ttyS1", &TTYS1_DEV);
#endif
#ifdef TTYS2_DEV
(void)uart_register("/dev/ttyS2", &TTYS2_DEV);
#endif
#ifdef TTYS3_DEV
(void)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)
{
struct u16550_s *priv = (struct u16550_s*)CONSOLE_DEV.priv;
#ifndef CONFIG_SUPPRESS_SERIAL_INTS
uart_datawidth_t ier;
u16550_disableuartint(priv, &ier);
#endif
/* Check for LF */
if (ch == '\n')
{
/* Add CR */
u16550_putc(priv, '\r');
}
u16550_putc(priv, ch);
#ifndef CONFIG_SUPPRESS_SERIAL_INTS
u16550_restoreuartint(priv, ier);
#endif
return ch;
}
#endif
#endif /* CONFIG_UART_16550 */
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