/* * Copyright (c) 2010 Lenka Trochtova * Copyright (c) 2011 Jiri Svoboda * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * - 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. * - The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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. */ /** * @defgroup ns8250 Serial port driver. * @brief HelenOS serial port driver. * @{ */ /** @file */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "cyclic_buffer.h" #define NAME "ns8250" #define REG_COUNT 7 #define MAX_BAUD_RATE 115200 #define DLAB_MASK (1 << 7) /** Interrupt Enable Register definition. */ #define NS8250_IER_RXREADY (1 << 0) #define NS8250_IER_THRE (1 << 1) #define NS8250_IER_RXSTATUS (1 << 2) #define NS8250_IER_MODEM_STATUS (1 << 3) /** Interrupt ID Register definition. */ #define NS8250_IID_ACTIVE (1 << 0) #define NS8250_IID_CAUSE_MASK 0x0e #define NS8250_IID_CAUSE_RXSTATUS 0x06 /** FIFO Control Register definition. */ #define NS8250_FCR_FIFOENABLE (1 << 0) #define NS8250_FCR_RXFIFORESET (1 << 1) #define NS8250_FCR_TXFIFORESET (1 << 2) #define NS8250_FCR_DMAMODE (1 << 3) #define NS8250_FCR_RXTRIGGERLOW (1 << 6) #define NS8250_FCR_RXTRIGGERHI (1 << 7) /** Line Control Register definition. */ #define NS8250_LCR_STOPBITS (1 << 2) #define NS8250_LCR_PARITY (1 << 3) #define NS8250_LCR_SENDBREAK (1 << 6) #define NS8250_LCR_DLAB (1 << 7) /** Modem Control Register definition. */ #define NS8250_MCR_DTR (1 << 0) #define NS8250_MCR_RTS (1 << 1) #define NS8250_MCR_OUT1 (1 << 2) #define NS8250_MCR_OUT2 (1 << 3) #define NS8250_MCR_LOOPBACK (1 << 4) #define NS8250_MCR_ALL (0x1f) /** Line Status Register definition. */ #define NS8250_LSR_RXREADY (1 << 0) #define NS8250_LSR_OE (1 << 1) #define NS8250_LSR_PE (1 << 2) #define NS8250_LSR_FE (1 << 3) #define NS8250_LSR_BREAK (1 << 4) #define NS8250_LSR_THRE (1 << 5) #define NS8250_LSR_TSE (1 << 6) /** Modem Status Register definition. */ #define NS8250_MSR_DELTACTS (1 << 0) #define NS8250_MSR_DELTADSR (1 << 1) #define NS8250_MSR_RITRAILING (1 << 2) #define NS8250_MSR_DELTADCD (1 << 3) #define NS8250_MSR_CTS (1 << 4) #define NS8250_MSR_DSR (1 << 5) #define NS8250_MSR_RI (1 << 6) #define NS8250_MSR_DCD (1 << 7) #define NS8250_MSR_SIGNALS (NS8250_MSR_CTS | NS8250_MSR_DSR \ | NS8250_MSR_RI | NS8250_MSR_DCD) /** The number of bits of one data unit send by the serial port. */ typedef enum { WORD_LENGTH_5, WORD_LENGTH_6, WORD_LENGTH_7, WORD_LENGTH_8 } word_length_t; /** The number of stop bits used by the serial port. */ typedef enum { /** Use one stop bit. */ ONE_STOP_BIT, /** 1.5 stop bits for word length 5, 2 stop bits otherwise. */ TWO_STOP_BITS } stop_bit_t; /** 8250 UART registers layout. */ typedef struct { ioport8_t data; /**< Data register. */ ioport8_t ier; /**< Interrupt Enable Reg. */ ioport8_t iid; /**< Interrupt ID Reg. */ ioport8_t lcr; /**< Line Control Reg. */ ioport8_t mcr; /**< Modem Control Reg. */ ioport8_t lsr; /**< Line Status Reg. */ ioport8_t msr; /**< Modem Status Reg. */ } ns8250_regs_t; /** The driver data for the serial port devices. */ typedef struct ns8250 { /** DDF device node */ ddf_dev_t *dev; /** DDF function node */ ddf_fun_t *fun; /** I/O registers **/ ns8250_regs_t *regs; /** Are there any clients connected to the device? */ unsigned client_connections; /** The irq assigned to this device. */ int irq; /** The base i/o address of the devices registers. */ uint32_t io_addr; /** The i/o port used to access the serial ports registers. */ ioport8_t *port; /** The buffer for incoming data. */ cyclic_buffer_t input_buffer; /** The fibril mutex for synchronizing the access to the device. */ fibril_mutex_t mutex; /** Indicates that some data has become available */ fibril_condvar_t input_buffer_available; /** True if device is removed. */ bool removed; } ns8250_t; /** Obtain soft-state structure from device node */ static ns8250_t *dev_ns8250(ddf_dev_t *dev) { return ddf_dev_data_get(dev); } /** Obtain soft-state structure from function node */ static ns8250_t *fun_ns8250(ddf_fun_t *fun) { return dev_ns8250(ddf_fun_get_dev(fun)); } /** Find out if there is some incoming data available on the serial port. * * @param port The base address of the serial port device's ports. * @return True if there are data waiting to be read, false * otherwise. */ static bool ns8250_received(ns8250_regs_t *regs) { return (pio_read_8(®s->lsr) & NS8250_LSR_RXREADY) != 0; } /** Read one byte from the serial port. * * @param port The base address of the serial port device's ports. * @return The data read. */ static uint8_t ns8250_read_8(ns8250_regs_t *regs) { return pio_read_8(®s->data); } /** Find out wheter it is possible to send data. * * @param port The base address of the serial port device's ports. */ static bool is_transmit_empty(ns8250_regs_t *regs) { return (pio_read_8(®s->lsr) & NS8250_LSR_THRE) != 0; } /** Write one character on the serial port. * * @param port The base address of the serial port device's ports. * @param c The character to be written to the serial port device. */ static void ns8250_write_8(ns8250_regs_t *regs, uint8_t c) { while (!is_transmit_empty(regs)) ; pio_write_8(®s->data, c); } /** Read data from the serial port device. * * @param fun The serial port function * @param buf The output buffer for read data. * @param count The number of bytes to be read. * * @return The number of bytes actually read on success, negative * error number otherwise. */ static int ns8250_read(ddf_fun_t *fun, char *buf, size_t count) { ns8250_t *ns = fun_ns8250(fun); int ret = 0; if (count == 0) return 0; fibril_mutex_lock(&ns->mutex); while (buf_is_empty(&ns->input_buffer)) fibril_condvar_wait(&ns->input_buffer_available, &ns->mutex); while (!buf_is_empty(&ns->input_buffer) && (size_t)ret < count) { buf[ret] = (char)buf_pop_front(&ns->input_buffer); ret++; } fibril_mutex_unlock(&ns->mutex); return ret; } /** Write a character to the serial port. * * @param ns Serial port device * @param c The character to be written */ static inline void ns8250_putchar(ns8250_t *ns, uint8_t c) { fibril_mutex_lock(&ns->mutex); ns8250_write_8(ns->regs, c); fibril_mutex_unlock(&ns->mutex); } /** Write data to the serial port. * * @param fun The serial port function * @param buf The data to be written * @param count The number of bytes to be written * @return Zero on success */ static int ns8250_write(ddf_fun_t *fun, char *buf, size_t count) { ns8250_t *ns = fun_ns8250(fun); size_t idx; for (idx = 0; idx < count; idx++) ns8250_putchar(ns, (uint8_t) buf[idx]); return count; } static ddf_dev_ops_t ns8250_dev_ops; /** The character interface's callbacks. */ static char_dev_ops_t ns8250_char_dev_ops = { .read = &ns8250_read, .write = &ns8250_write }; static int ns8250_dev_add(ddf_dev_t *dev); static int ns8250_dev_remove(ddf_dev_t *dev); /** The serial port device driver's standard operations. */ static driver_ops_t ns8250_ops = { .dev_add = &ns8250_dev_add, .dev_remove = &ns8250_dev_remove }; /** The serial port device driver structure. */ static driver_t ns8250_driver = { .name = NAME, .driver_ops = &ns8250_ops }; /** Clean up the serial port soft-state * * @param ns Serial port device */ static void ns8250_dev_cleanup(ns8250_t *ns) { } /** Enable the i/o ports of the device. * * @param ns Serial port device * @return True on success, false otherwise */ static bool ns8250_pio_enable(ns8250_t *ns) { ddf_msg(LVL_DEBUG, "ns8250_pio_enable %s", ddf_dev_get_name(ns->dev)); /* Gain control over port's registers. */ if (pio_enable((void *)(uintptr_t) ns->io_addr, REG_COUNT, (void **) &ns->port)) { ddf_msg(LVL_ERROR, "Cannot map the port %#" PRIx32 " for device %s.", ns->io_addr, ddf_dev_get_name(ns->dev)); return false; } ns->regs = (ns8250_regs_t *)ns->port; return true; } /** Probe the serial port device for its presence. * * @param ns Serial port device * @return True if the device is present, false otherwise */ static bool ns8250_dev_probe(ns8250_t *ns) { ddf_msg(LVL_DEBUG, "ns8250_dev_probe %s", ddf_dev_get_name(ns->dev)); bool res = true; uint8_t olddata; olddata = pio_read_8(&ns->regs->mcr); pio_write_8(&ns->regs->mcr, NS8250_MCR_LOOPBACK); if (pio_read_8(&ns->regs->msr) & NS8250_MSR_SIGNALS) res = false; pio_write_8(&ns->regs->mcr, NS8250_MCR_ALL); if ((pio_read_8(&ns->regs->msr) & NS8250_MSR_SIGNALS) != NS8250_MSR_SIGNALS) res = false; pio_write_8(&ns->regs->mcr, olddata); if (!res) { ddf_msg(LVL_DEBUG, "Device %s is not present.", ddf_dev_get_name(ns->dev)); } return res; } /** Initialize serial port device. * * @param ns Serial port device * @return Zero on success, negative error number otherwise */ static int ns8250_dev_initialize(ns8250_t *ns) { async_sess_t *parent_sess; int ret = EOK; ddf_msg(LVL_DEBUG, "ns8250_dev_initialize %s", ddf_dev_get_name(ns->dev)); hw_resource_list_t hw_resources; memset(&hw_resources, 0, sizeof(hw_resource_list_t)); /* Connect to the parent's driver. */ parent_sess = ddf_dev_parent_sess_create(ns->dev, EXCHANGE_SERIALIZE); if (parent_sess == NULL) { ddf_msg(LVL_ERROR, "Failed to connect to parent driver of " "device %s.", ddf_dev_get_name(ns->dev)); ret = ENOENT; goto failed; } /* Get hw resources. */ ret = hw_res_get_resource_list(parent_sess, &hw_resources); if (ret != EOK) { ddf_msg(LVL_ERROR, "Failed to get HW resources for device " "%s.", ddf_dev_get_name(ns->dev)); goto failed; } size_t i; hw_resource_t *res; bool irq = false; bool ioport = false; for (i = 0; i < hw_resources.count; i++) { res = &hw_resources.resources[i]; switch (res->type) { case INTERRUPT: ns->irq = res->res.interrupt.irq; irq = true; ddf_msg(LVL_NOTE, "Device %s was assigned irq = 0x%x.", ddf_dev_get_name(ns->dev), ns->irq); break; case IO_RANGE: ns->io_addr = res->res.io_range.address; if (res->res.io_range.size < REG_COUNT) { ddf_msg(LVL_ERROR, "I/O range assigned to " "device %s is too small.", ddf_dev_get_name(ns->dev)); ret = ELIMIT; goto failed; } ioport = true; ddf_msg(LVL_NOTE, "Device %s was assigned I/O address = " "0x%x.", ddf_dev_get_name(ns->dev), ns->io_addr); break; default: break; } } if (!irq || !ioport) { ddf_msg(LVL_ERROR, "Missing HW resource(s) for device %s.", ddf_dev_get_name(ns->dev)); ret = ENOENT; goto failed; } hw_res_clean_resource_list(&hw_resources); return ret; failed: ns8250_dev_cleanup(ns); hw_res_clean_resource_list(&hw_resources); return ret; } /** Enable interrupts on the serial port device. * * Interrupt when data is received * * @param port The base address of the serial port device's ports. */ static inline void ns8250_port_interrupts_enable(ns8250_regs_t *regs) { /* Interrupt when data received. */ pio_write_8(®s->ier, NS8250_IER_RXREADY | NS8250_IER_RXSTATUS); pio_write_8(®s->mcr, NS8250_MCR_DTR | NS8250_MCR_RTS | NS8250_MCR_OUT2); } /** Disable interrupts on the serial port device. * * @param port The base address of the serial port device's ports */ static inline void ns8250_port_interrupts_disable(ns8250_regs_t *regs) { pio_write_8(®s->ier, 0x0); /* Disable all interrupts. */ } /** Enable interrupts for the serial port device. * * @param ns Serial port device * @return Zero on success, negative error number otherwise */ static int ns8250_interrupt_enable(ns8250_t *ns) { /* Enable interrupt using IRC service. */ int rc = irc_enable_interrupt(ns->irq); if (rc != EOK) return EIO; /* Read LSR to clear possible previous LSR interrupt */ pio_read_8(&ns->regs->lsr); /* Enable interrupt on the serial port. */ ns8250_port_interrupts_enable(ns->regs); return EOK; } /** Set Divisor Latch Access Bit. * * When the Divisor Latch Access Bit is set, it is possible to set baud rate of * the serial port device. * * @param port The base address of the serial port device's ports. */ static inline void enable_dlab(ns8250_regs_t *regs) { uint8_t val = pio_read_8(®s->lcr); pio_write_8(®s->lcr, val | NS8250_LCR_DLAB); } /** Clear Divisor Latch Access Bit. * * @param port The base address of the serial port device's ports. */ static inline void clear_dlab(ns8250_regs_t *regs) { uint8_t val = pio_read_8(®s->lcr); pio_write_8(®s->lcr, val & (~NS8250_LCR_DLAB)); } /** Set baud rate of the serial communication on the serial device. * * @param port The base address of the serial port device's ports. * @param baud_rate The baud rate to be used by the device. * @return Zero on success, negative error number otherwise (EINVAL * if the specified baud_rate is not valid). */ static int ns8250_port_set_baud_rate(ns8250_regs_t *regs, unsigned int baud_rate) { uint16_t divisor; uint8_t div_low, div_high; if (baud_rate < 50 || MAX_BAUD_RATE % baud_rate != 0) { ddf_msg(LVL_ERROR, "Invalid baud rate %d requested.", baud_rate); return EINVAL; } divisor = MAX_BAUD_RATE / baud_rate; div_low = (uint8_t)divisor; div_high = (uint8_t)(divisor >> 8); /* Enable DLAB to be able to access baud rate divisor. */ enable_dlab(regs); /* Set divisor low byte. */ pio_write_8(®s->data, div_low); /* Set divisor high byte. */ pio_write_8(®s->ier, div_high); clear_dlab(regs); return EOK; } /** Get baud rate used by the serial port device. * * @param port The base address of the serial port device's ports. * @param baud_rate The ouput parameter to which the baud rate is stored. */ static unsigned int ns8250_port_get_baud_rate(ns8250_regs_t *regs) { uint16_t divisor; uint8_t div_low, div_high; /* Enable DLAB to be able to access baud rate divisor. */ enable_dlab(regs); /* Get divisor low byte. */ div_low = pio_read_8(®s->data); /* Get divisor high byte. */ div_high = pio_read_8(®s->ier); clear_dlab(regs); divisor = (div_high << 8) | div_low; return MAX_BAUD_RATE / divisor; } /** Get the parameters of the serial communication set on the serial port * device. * * @param parity The parity used. * @param word_length The length of one data unit in bits. * @param stop_bits The number of stop bits used (one or two). */ static void ns8250_port_get_com_props(ns8250_regs_t *regs, unsigned int *parity, unsigned int *word_length, unsigned int *stop_bits) { uint8_t val; val = pio_read_8(®s->lcr); *parity = ((val >> NS8250_LCR_PARITY) & 7); /* Silence warnings */ *word_length = 0; switch (val & 3) { case WORD_LENGTH_5: *word_length = 5; break; case WORD_LENGTH_6: *word_length = 6; break; case WORD_LENGTH_7: *word_length = 7; break; case WORD_LENGTH_8: *word_length = 8; break; } if ((val >> NS8250_LCR_STOPBITS) & 1) *stop_bits = 2; else *stop_bits = 1; } /** Set the parameters of the serial communication on the serial port device. * * @param parity The parity to be used. * @param word_length The length of one data unit in bits. * @param stop_bits The number of stop bits used (one or two). * @return Zero on success, EINVAL if some of the specified values * is invalid. */ static int ns8250_port_set_com_props(ns8250_regs_t *regs, unsigned int parity, unsigned int word_length, unsigned int stop_bits) { uint8_t val; switch (word_length) { case 5: val = WORD_LENGTH_5; break; case 6: val = WORD_LENGTH_6; break; case 7: val = WORD_LENGTH_7; break; case 8: val = WORD_LENGTH_8; break; default: return EINVAL; } switch (stop_bits) { case 1: val |= ONE_STOP_BIT << NS8250_LCR_STOPBITS; break; case 2: val |= TWO_STOP_BITS << NS8250_LCR_STOPBITS; break; default: return EINVAL; } switch (parity) { case SERIAL_NO_PARITY: case SERIAL_ODD_PARITY: case SERIAL_EVEN_PARITY: case SERIAL_MARK_PARITY: case SERIAL_SPACE_PARITY: val |= parity << NS8250_LCR_PARITY; break; default: return EINVAL; } pio_write_8(®s->lcr, val); return EOK; } /** Initialize the serial port device. * * Set the default parameters of the serial communication. * * @param ns Serial port device */ static void ns8250_initialize_port(ns8250_t *ns) { /* Disable interrupts. */ ns8250_port_interrupts_disable(ns->regs); /* Set baud rate. */ ns8250_port_set_baud_rate(ns->regs, 38400); /* 8 bits, no parity, two stop bits. */ ns8250_port_set_com_props(ns->regs, SERIAL_NO_PARITY, 8, 2); /* * Enable FIFO, clear them, with 4-byte threshold for greater * reliability. */ pio_write_8(&ns->regs->iid, NS8250_FCR_FIFOENABLE | NS8250_FCR_RXFIFORESET | NS8250_FCR_TXFIFORESET | NS8250_FCR_RXTRIGGERLOW); /* * RTS/DSR set (Request to Send and Data Terminal Ready lines enabled), * Aux Output2 set - needed for interrupts. */ pio_write_8(&ns->regs->mcr, NS8250_MCR_DTR | NS8250_MCR_RTS | NS8250_MCR_OUT2); } /** Deinitialize the serial port device. * * @param ns Serial port device */ static void ns8250_port_cleanup(ns8250_t *ns) { /* Disable FIFO */ pio_write_8(&ns->regs->iid, 0x00); /* Disable DTR, RTS, OUT1, OUT2 (int. enable) */ pio_write_8(&ns->regs->mcr, 0x00); /* Disable all interrupts from the port */ ns8250_port_interrupts_disable(ns->regs); } /** Read the data from the serial port device and store them to the input * buffer. * * @param ns Serial port device */ static void ns8250_read_from_device(ns8250_t *ns) { ns8250_regs_t *regs = ns->regs; bool cont = true; fibril_mutex_lock(&ns->mutex); while (cont) { cont = ns8250_received(regs); if (cont) { uint8_t val = ns8250_read_8(regs); if (ns->client_connections > 0) { bool buf_was_empty = buf_is_empty(&ns->input_buffer); if (!buf_push_back(&ns->input_buffer, val)) { ddf_msg(LVL_WARN, "Buffer overflow on " "%s.", ddf_dev_get_name(ns->dev)); break; } else { ddf_msg(LVL_DEBUG2, "Character %c saved " "to the buffer of %s.", val, ddf_dev_get_name(ns->dev)); if (buf_was_empty) fibril_condvar_broadcast(&ns->input_buffer_available); } } } } fibril_mutex_unlock(&ns->mutex); fibril_yield(); } /** The interrupt handler. * * The serial port is initialized to interrupt when some data come or line * status register changes, so the interrupt is handled by reading the incoming * data and reading the line status register. * * @param dev The serial port device. */ static inline void ns8250_interrupt_handler(ddf_dev_t *dev, ipc_callid_t iid, ipc_call_t *icall) { ns8250_t *ns = dev_ns8250(dev); uint8_t iir = pio_read_8(&ns->regs->iid); if ((iir & NS8250_IID_CAUSE_MASK) == NS8250_IID_CAUSE_RXSTATUS) { uint8_t lsr = pio_read_8(&ns->regs->lsr); if (lsr & NS8250_LSR_OE) { ddf_msg(LVL_WARN, "Overrun error on %s", ddf_dev_get_name(ns->dev)); } } ns8250_read_from_device(ns); } /** Register the interrupt handler for the device. * * @param ns Serial port device */ static inline int ns8250_register_interrupt_handler(ns8250_t *ns) { return register_interrupt_handler(ns->dev, ns->irq, ns8250_interrupt_handler, NULL); } /** Unregister the interrupt handler for the device. * * @param ns Serial port device */ static inline int ns8250_unregister_interrupt_handler(ns8250_t *ns) { return unregister_interrupt_handler(ns->dev, ns->irq); } /** The dev_add callback method of the serial port driver. * * Probe and initialize the newly added device. * * @param dev The serial port device. */ static int ns8250_dev_add(ddf_dev_t *dev) { ns8250_t *ns = NULL; ddf_fun_t *fun = NULL; bool need_cleanup = false; bool need_unreg_intr_handler = false; int rc; ddf_msg(LVL_DEBUG, "ns8250_dev_add %s (handle = %d)", ddf_dev_get_name(dev), (int) ddf_dev_get_handle(dev)); /* Allocate soft-state for the device */ ns = ddf_dev_data_alloc(dev, sizeof(ns8250_t)); if (ns == NULL) { rc = ENOMEM; goto fail; } fibril_mutex_initialize(&ns->mutex); fibril_condvar_initialize(&ns->input_buffer_available); ns->dev = dev; rc = ns8250_dev_initialize(ns); if (rc != EOK) goto fail; need_cleanup = true; if (!ns8250_pio_enable(ns)) { rc = EADDRNOTAVAIL; goto fail; } /* Find out whether the device is present. */ if (!ns8250_dev_probe(ns)) { rc = ENOENT; goto fail; } /* Serial port initialization (baud rate etc.). */ ns8250_initialize_port(ns); /* Register interrupt handler. */ if (ns8250_register_interrupt_handler(ns) != EOK) { ddf_msg(LVL_ERROR, "Failed to register interrupt handler."); rc = EADDRNOTAVAIL; goto fail; } need_unreg_intr_handler = true; /* Enable interrupt. */ rc = ns8250_interrupt_enable(ns); if (rc != EOK) { ddf_msg(LVL_ERROR, "Failed to enable the interrupt. Error code = " "%d.", rc); goto fail; } fun = ddf_fun_create(dev, fun_exposed, "a"); if (fun == NULL) { ddf_msg(LVL_ERROR, "Failed creating function."); goto fail; } /* Set device operations. */ ddf_fun_set_ops(fun, &ns8250_dev_ops); rc = ddf_fun_bind(fun); if (rc != EOK) { ddf_msg(LVL_ERROR, "Failed binding function."); goto fail; } ns->fun = fun; ddf_fun_add_to_category(fun, "serial"); ddf_msg(LVL_NOTE, "Device %s successfully initialized.", ddf_dev_get_name(dev)); return EOK; fail: if (fun != NULL) ddf_fun_destroy(fun); if (need_unreg_intr_handler) ns8250_unregister_interrupt_handler(ns); if (need_cleanup) ns8250_dev_cleanup(ns); return rc; } static int ns8250_dev_remove(ddf_dev_t *dev) { ns8250_t *ns = dev_ns8250(dev); int rc; fibril_mutex_lock(&ns->mutex); if (ns->client_connections > 0) { fibril_mutex_unlock(&ns->mutex); return EBUSY; } ns->removed = true; fibril_mutex_unlock(&ns->mutex); rc = ddf_fun_unbind(ns->fun); if (rc != EOK) { ddf_msg(LVL_ERROR, "Failed to unbind function."); return rc; } ddf_fun_destroy(ns->fun); ns8250_port_cleanup(ns); ns8250_unregister_interrupt_handler(ns); ns8250_dev_cleanup(ns); return EOK; } /** Open the device. * * This is a callback function called when a client tries to connect to the * device. * * @param dev The device. */ static int ns8250_open(ddf_fun_t *fun) { ns8250_t *ns = fun_ns8250(fun); int res; fibril_mutex_lock(&ns->mutex); if (ns->removed) { res = ENXIO; } else { res = EOK; ns->client_connections++; } fibril_mutex_unlock(&ns->mutex); return res; } /** Close the device. * * This is a callback function called when a client tries to disconnect from * the device. * * @param dev The device. */ static void ns8250_close(ddf_fun_t *fun) { ns8250_t *data = fun_ns8250(fun); fibril_mutex_lock(&data->mutex); assert(data->client_connections > 0); if (!(--data->client_connections)) buf_clear(&data->input_buffer); fibril_mutex_unlock(&data->mutex); } /** Get parameters of the serial communication which are set to the specified * device. * * @param dev The serial port device. * @param baud_rate The baud rate used by the device. * @param parity The type of parity used by the device. * @param word_length The size of one data unit in bits. * @param stop_bits The number of stop bits used. */ static void ns8250_get_props(ddf_dev_t *dev, unsigned int *baud_rate, unsigned int *parity, unsigned int *word_length, unsigned int* stop_bits) { ns8250_t *data = dev_ns8250(dev); ns8250_regs_t *regs = data->regs; fibril_mutex_lock(&data->mutex); ns8250_port_interrupts_disable(regs); *baud_rate = ns8250_port_get_baud_rate(regs); ns8250_port_get_com_props(regs, parity, word_length, stop_bits); ns8250_port_interrupts_enable(regs); fibril_mutex_unlock(&data->mutex); ddf_msg(LVL_DEBUG, "ns8250_get_props: baud rate %d, parity 0x%x, word " "length %d, stop bits %d", *baud_rate, *parity, *word_length, *stop_bits); } /** Set parameters of the serial communication to the specified serial port * device. * * @param dev The serial port device. * @param baud_rate The baud rate to be used by the device. * @param parity The type of parity to be used by the device. * @param word_length The size of one data unit in bits. * @param stop_bits The number of stop bits to be used. */ static int ns8250_set_props(ddf_dev_t *dev, unsigned int baud_rate, unsigned int parity, unsigned int word_length, unsigned int stop_bits) { ddf_msg(LVL_DEBUG, "ns8250_set_props: baud rate %d, parity 0x%x, word " "length %d, stop bits %d", baud_rate, parity, word_length, stop_bits); ns8250_t *data = dev_ns8250(dev); ns8250_regs_t *regs = data->regs; int ret; fibril_mutex_lock(&data->mutex); ns8250_port_interrupts_disable(regs); ret = ns8250_port_set_baud_rate(regs, baud_rate); if (ret == EOK) ret = ns8250_port_set_com_props(regs, parity, word_length, stop_bits); ns8250_port_interrupts_enable(regs); fibril_mutex_unlock(&data->mutex); return ret; } /** Default handler for client requests which are not handled by the standard * interfaces. * * Configure the parameters of the serial communication. */ static void ns8250_default_handler(ddf_fun_t *fun, ipc_callid_t callid, ipc_call_t *call) { sysarg_t method = IPC_GET_IMETHOD(*call); int ret; unsigned int baud_rate, parity, word_length, stop_bits; switch (method) { case SERIAL_GET_COM_PROPS: ns8250_get_props(ddf_fun_get_dev(fun), &baud_rate, &parity, &word_length, &stop_bits); async_answer_4(callid, EOK, baud_rate, parity, word_length, stop_bits); break; case SERIAL_SET_COM_PROPS: baud_rate = IPC_GET_ARG1(*call); parity = IPC_GET_ARG2(*call); word_length = IPC_GET_ARG3(*call); stop_bits = IPC_GET_ARG4(*call); ret = ns8250_set_props(ddf_fun_get_dev(fun), baud_rate, parity, word_length, stop_bits); async_answer_0(callid, ret); break; default: async_answer_0(callid, ENOTSUP); } } /** Initialize the serial port driver. * * Initialize device operations structures with callback methods for handling * client requests to the serial port devices. */ static void ns8250_init(void) { ddf_log_init(NAME); ns8250_dev_ops.open = &ns8250_open; ns8250_dev_ops.close = &ns8250_close; ns8250_dev_ops.interfaces[CHAR_DEV_IFACE] = &ns8250_char_dev_ops; ns8250_dev_ops.default_handler = &ns8250_default_handler; } int main(int argc, char *argv[]) { printf(NAME ": HelenOS serial port driver\n"); ns8250_init(); return ddf_driver_main(&ns8250_driver); } /** * @} */