/**************************************************************************** * drivers/serial/uart_16550.c * Serial driver for 16550 UART * * Copyright (C) 2011 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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 */