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Diffstat (limited to 'nuttx/drivers/analog/dac.c')
-rw-r--r--nuttx/drivers/analog/dac.c498
1 files changed, 498 insertions, 0 deletions
diff --git a/nuttx/drivers/analog/dac.c b/nuttx/drivers/analog/dac.c
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+++ b/nuttx/drivers/analog/dac.c
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+/****************************************************************************
+ * drivers/analog/dac.c
+ *
+ * Copyright (C) 2011 Li Zhuoyi. All rights reserved.
+ * Author: Li Zhuoyi <lzyy.cn@gmail.com>
+ * History: 0.1 2011-08-04 initial version
+ *
+ * Derived from drivers/can.c
+ *
+ * Copyright (C) 2008-2009Gregory Nutt. All rights reserved.
+ * Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * 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 <string.h>
+#include <semaphore.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/fs.h>
+#include <nuttx/arch.h>
+#include <nuttx/analog/dac.h>
+
+#include <arch/irq.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define HALF_SECOND_MSEC 500
+#define HALF_SECOND_USEC 500000L
+
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int dac_open(FAR struct file *filep);
+static int dac_close(FAR struct file *filep);
+static ssize_t dac_read(FAR struct file *, FAR char *, size_t);
+static ssize_t dac_write(FAR struct file *filep, FAR const char *buffer, size_t buflen);
+static int dac_ioctl(FAR struct file *filep,int cmd,unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static const struct file_operations dac_fops =
+{
+ dac_open,
+ dac_close,
+ dac_read,
+ dac_write,
+ 0,
+ dac_ioctl
+#ifndef CONFIG_DISABLE_POLL
+ , 0
+#endif
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+/************************************************************************************
+ * Name: dac_open
+ *
+ * Description:
+ * This function is called whenever the DAC device is opened.
+ *
+ ************************************************************************************/
+
+static int dac_open(FAR struct file *filep)
+{
+ FAR struct inode *inode = filep->f_inode;
+ FAR struct dac_dev_s *dev = inode->i_private;
+ uint8_t tmp;
+ int ret = OK;
+
+ /* If the port is the middle of closing, wait until the close is finished */
+
+ if (sem_wait(&dev->ad_closesem) != OK)
+ {
+ ret = -errno;
+ }
+ else
+ {
+ /* Increment the count of references to the device. If this the first
+ * time that the driver has been opened for this device, then initialize
+ * the device.
+ */
+
+ tmp = dev->ad_ocount + 1;
+ if (tmp == 0)
+ {
+ /* More than 255 opens; uint8_t overflows to zero */
+
+ ret = -EMFILE;
+ }
+ else
+ {
+ /* Check if this is the first time that the driver has been opened. */
+
+ if (tmp == 1)
+ {
+ /* Yes.. perform one time hardware initialization. */
+
+ irqstate_t flags = irqsave();
+ ret = dev->ad_ops->ao_setup(dev);
+ if (ret == OK)
+ {
+ /* Mark the FIFOs empty */
+
+ dev->ad_xmit.af_head = 0;
+ dev->ad_xmit.af_tail = 0;
+
+ /* Save the new open count on success */
+
+ dev->ad_ocount = tmp;
+ }
+ irqrestore(flags);
+ }
+ }
+ sem_post(&dev->ad_closesem);
+ }
+ return ret;
+}
+
+/************************************************************************************
+ * Name: dac_close
+ *
+ * Description:
+ * This routine is called when the DAC device is closed.
+ * It waits for the last remaining data to be sent.
+ *
+ ************************************************************************************/
+
+static int dac_close(FAR struct file *filep)
+{
+ FAR struct inode *inode = filep->f_inode;
+ FAR struct dac_dev_s *dev = inode->i_private;
+ irqstate_t flags;
+ int ret = OK;
+
+ if (sem_wait(&dev->ad_closesem) != OK)
+ {
+ ret = -errno;
+ }
+ else
+ {
+ /* Decrement the references to the driver. If the reference count will
+ * decrement to 0, then uninitialize the driver.
+ */
+
+ if (dev->ad_ocount > 1)
+ {
+ dev->ad_ocount--;
+ sem_post(&dev->ad_closesem);
+ }
+ else
+ {
+ /* There are no more references to the port */
+
+ dev->ad_ocount = 0;
+
+ /* Now we wait for the transmit FIFO to clear */
+
+ while (dev->ad_xmit.af_head != dev->ad_xmit.af_tail)
+ {
+#ifndef CONFIG_DISABLE_SIGNALS
+ usleep(HALF_SECOND_USEC);
+#else
+ up_mdelay(HALF_SECOND_MSEC);
+#endif
+ }
+
+ /* Free the IRQ and disable the DAC device */
+
+ flags = irqsave(); /* Disable interrupts */
+ dev->ad_ops->ao_shutdown(dev); /* Disable the DAC */
+ irqrestore(flags);
+
+ sem_post(&dev->ad_closesem);
+ }
+ }
+ return ret;
+}
+
+/****************************************************************************
+ * Name: dac_read
+ ****************************************************************************/
+
+static ssize_t dac_read(FAR struct file *filep, FAR char *buffer, size_t buflen)
+{
+ return 0;
+}
+
+/************************************************************************************
+ * Name: dac_xmit
+ *
+ * Description:
+ * Send the message at the head of the ad_xmit FIFO
+ *
+ * Assumptions:
+ * Called with interrupts disabled
+ *
+ ************************************************************************************/
+
+static int dac_xmit(FAR struct dac_dev_s *dev)
+{
+ bool enable = false;
+ int ret = OK;
+
+ /* Check if the xmit FIFO is empty */
+
+ if (dev->ad_xmit.af_head != dev->ad_xmit.af_tail)
+ {
+ /* Send the next message at the head of the FIFO */
+
+ ret = dev->ad_ops->ao_send(dev, &dev->ad_xmit.af_buffer[dev->ad_xmit.af_head]);
+
+ /* Make sure the TX done interrupts are enabled */
+
+ enable = (ret == OK ? true : false);
+ }
+ dev->ad_ops->ao_txint(dev, enable);
+ return ret;
+}
+
+/************************************************************************************
+ * Name: dac_write
+ ************************************************************************************/
+
+static ssize_t dac_write(FAR struct file *filep, FAR const char *buffer, size_t buflen)
+{
+ FAR struct inode *inode = filep->f_inode;
+ FAR struct dac_dev_s *dev = inode->i_private;
+ FAR struct dac_fifo_s *fifo = &dev->ad_xmit;
+ FAR struct dac_msg_s *msg;
+ bool empty = false;
+ ssize_t nsent = 0;
+ irqstate_t flags;
+ int nexttail;
+ int msglen;
+ int ret = 0;
+
+ /* Interrupts must disabled throughout the following */
+
+ flags = irqsave();
+
+ /* Check if the TX FIFO was empty when we started. That is a clue that we have
+ * to kick off a new TX sequence.
+ */
+
+ empty = (fifo->af_head == fifo->af_tail);
+
+ /* Add the messages to the FIFO. Ignore any trailing messages that are
+ * shorter than the minimum.
+ */
+
+ if (buflen % 5 ==0 )
+ msglen=5;
+ else if (buflen % 4 ==0 )
+ msglen=4;
+ else if (buflen % 3 ==0 )
+ msglen=3;
+ else if (buflen % 2 ==0 )
+ msglen=2;
+ else if (buflen == 1)
+ msglen=1;
+ else
+ msglen=5;
+
+ while ((buflen - nsent) >= msglen )
+ {
+ /* Check if adding this new message would over-run the drivers ability to enqueue
+ * xmit data.
+ */
+
+ nexttail = fifo->af_tail + 1;
+ if (nexttail >= CONFIG_DAC_FIFOSIZE)
+ {
+ nexttail = 0;
+ }
+
+ /* If the XMIT fifo becomes full, then wait for space to become available */
+
+ while (nexttail == fifo->af_head)
+ {
+ /* The transmit FIFO is full -- was non-blocking mode selected? */
+
+ if (filep->f_oflags & O_NONBLOCK)
+ {
+ if (nsent == 0)
+ {
+ ret = -EAGAIN;
+ }
+ else
+ {
+ ret = nsent;
+ }
+ goto return_with_irqdisabled;
+ }
+
+ /* If the FIFO was empty when we started, then we will have
+ * start the XMIT sequence to clear the FIFO.
+ */
+
+ if (empty)
+ {
+ dac_xmit(dev);
+ }
+
+ /* Wait for a message to be sent */
+
+ do
+ {
+ ret = sem_wait(&fifo->af_sem);
+ if (ret < 0 && errno != EINTR)
+ {
+ ret = -errno;
+ goto return_with_irqdisabled;
+ }
+ }
+ while (ret < 0);
+
+ /* Re-check the FIFO state */
+
+ empty = (fifo->af_head == fifo->af_tail);
+ }
+
+ /* We get here if there is space at the end of the FIFO. Add the new
+ * CAN message at the tail of the FIFO.
+ */
+ if(msglen==5)
+ {
+ msg = (FAR struct dac_msg_s *)&buffer[nsent];
+ memcpy(&fifo->af_buffer[fifo->af_tail], msg, msglen);
+ }
+ else if(msglen == 4)
+ {
+ fifo->af_buffer[fifo->af_tail].am_channel=buffer[nsent];
+ fifo->af_buffer[fifo->af_tail].am_data=*(uint32_t *)&buffer[nsent];
+ fifo->af_buffer[fifo->af_tail].am_data&=0xffffff00;
+ }
+ else if(msglen == 3)
+ {
+ fifo->af_buffer[fifo->af_tail].am_channel=buffer[nsent];
+ fifo->af_buffer[fifo->af_tail].am_data=(*(uint16_t *)&buffer[nsent+1]);
+ fifo->af_buffer[fifo->af_tail].am_data<<=16;
+ }
+ else if(msglen == 2)
+ {
+ fifo->af_buffer[fifo->af_tail].am_channel=0;
+ fifo->af_buffer[fifo->af_tail].am_data=(*(uint16_t *)&buffer[nsent]);
+ fifo->af_buffer[fifo->af_tail].am_data<<=16;
+ }
+ else if(msglen == 1)
+ {
+ fifo->af_buffer[fifo->af_tail].am_channel=0;
+ fifo->af_buffer[fifo->af_tail].am_data=buffer[nsent];
+ fifo->af_buffer[fifo->af_tail].am_data<<=24;
+ }
+ /* Increment the tail of the circular buffer */
+
+ fifo->af_tail = nexttail;
+
+ /* Increment the number of bytes that were sent */
+
+ nsent += msglen;
+ }
+
+ /* We get here after all messages have been added to the FIFO. Check if
+ * we need to kick of the XMIT sequence.
+ */
+
+ if (empty)
+ {
+ dac_xmit(dev);
+ }
+
+ /* Return the number of bytes that were sent */
+
+ ret = nsent;
+
+return_with_irqdisabled:
+ irqrestore(flags);
+ return ret;
+}
+
+/************************************************************************************
+ * Name: dac_ioctl
+ ************************************************************************************/
+
+static int dac_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
+{
+ FAR struct inode *inode = filep->f_inode;
+ FAR struct dac_dev_s *dev = inode->i_private;
+ int ret = OK;
+
+ ret = dev->ad_ops->ao_ioctl(dev, cmd, arg);
+ return ret;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/************************************************************************************
+ * Name: dac_txdone
+ *
+ * Description:
+ * Called from the DAC interrupt handler at the completion of a send operation.
+ *
+ * Return:
+ * OK on success; a negated errno on failure.
+ *
+ ************************************************************************************/
+
+int dac_txdone(FAR struct dac_dev_s *dev)
+{
+ int ret = -ENOENT;
+
+ /* Verify that the xmit FIFO is not empty */
+
+ if (dev->ad_xmit.af_head != dev->ad_xmit.af_tail)
+ {
+ /* Remove the message at the head of the xmit FIFO */
+
+ if (++dev->ad_xmit.af_head >= CONFIG_DAC_FIFOSIZE)
+ {
+ dev->ad_xmit.af_head = 0;
+ }
+
+ /* Send the next message in the FIFO */
+
+ ret = dac_xmit(dev);
+ if (ret == OK)
+ {
+ /* Inform any waiting threads that new xmit space is available */
+
+ ret = sem_post(&dev->ad_xmit.af_sem);
+ }
+ }
+ return ret;
+}
+
+int dac_register(FAR const char *path, FAR struct dac_dev_s *dev)
+{
+ /* Initialize the DAC device structure */
+
+ dev->ad_ocount = 0;
+
+ sem_init(&dev->ad_xmit.af_sem, 0, 0);
+ sem_init(&dev->ad_closesem, 0, 1);
+
+ dev->ad_ops->ao_reset(dev);
+
+ return register_driver(path, &dac_fops, 0555, dev);
+}
+
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