forked from Archive/PX4-Autopilot
424 lines
12 KiB
C
424 lines
12 KiB
C
/****************************************************************************
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* drivers/analog/adc.c
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*
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* Copyright (C) 2011 Li Zhuoyi. All rights reserved.
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* Author: Li Zhuoyi <lzyy.cn@gmail.com>
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* History: 0.1 2011-08-04 initial version
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*
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* Derived from drivers/can.c
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*
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* Copyright (C) 2008-2009 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <sys/types.h>
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#include <stdint.h>
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#include <stdbool.h>
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#include <unistd.h>
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#include <string.h>
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#include <semaphore.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <debug.h>
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#include <nuttx/fs/fs.h>
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#include <nuttx/arch.h>
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#include <nuttx/analog/adc.h>
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#include <arch/irq.h>
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/****************************************************************************
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* Private Function Prototypes
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****************************************************************************/
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static int adc_open(FAR struct file *filep);
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static int adc_close(FAR struct file *filep);
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static ssize_t adc_read(FAR struct file *, FAR char *, size_t);
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static ssize_t adc_write(FAR struct file *filep, FAR const char *buffer, size_t buflen);
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static int adc_ioctl(FAR struct file *filep,int cmd,unsigned long arg);
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/****************************************************************************
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* Private Data
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****************************************************************************/
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static const struct file_operations adc_fops =
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{
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adc_open, /* open */
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adc_close, /* close */
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adc_read, /* read */
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adc_write, /* write */
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0, /* seek */
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adc_ioctl /* ioctl */
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#ifndef CONFIG_DISABLE_POLL
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, 0 /* poll */
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#endif
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};
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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/************************************************************************************
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* Name: adc_open
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*
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* Description:
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* This function is called whenever the ADC device is opened.
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*
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************************************************************************************/
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static int adc_open(FAR struct file *filep)
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{
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FAR struct inode *inode = filep->f_inode;
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FAR struct adc_dev_s *dev = inode->i_private;
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uint8_t tmp;
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int ret = OK;
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/* If the port is the middle of closing, wait until the close is finished */
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if (sem_wait(&dev->ad_closesem) != OK)
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{
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ret = -errno;
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}
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else
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{
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/* Increment the count of references to the device. If this the first
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* time that the driver has been opened for this device, then initialize
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* the device.
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*/
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tmp = dev->ad_ocount + 1;
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if (tmp == 0)
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{
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/* More than 255 opens; uint8_t overflows to zero */
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ret = -EMFILE;
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}
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else
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{
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/* Check if this is the first time that the driver has been opened. */
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if (tmp == 1)
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{
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/* Yes.. perform one time hardware initialization. */
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irqstate_t flags = irqsave();
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ret = dev->ad_ops->ao_setup(dev);
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if (ret == OK)
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{
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/* Mark the FIFOs empty */
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dev->ad_recv.af_head = 0;
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dev->ad_recv.af_tail = 0;
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/* Finally, Enable the CAN RX interrupt */
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dev->ad_ops->ao_rxint(dev, true);
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/* Save the new open count on success */
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dev->ad_ocount = tmp;
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}
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irqrestore(flags);
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}
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}
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sem_post(&dev->ad_closesem);
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}
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return ret;
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}
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/************************************************************************************
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* Name: adc_close
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*
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* Description:
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* This routine is called when the ADC device is closed.
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* It waits for the last remaining data to be sent.
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*
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************************************************************************************/
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static int adc_close(FAR struct file *filep)
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{
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FAR struct inode *inode = filep->f_inode;
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FAR struct adc_dev_s *dev = inode->i_private;
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irqstate_t flags;
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int ret = OK;
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if (sem_wait(&dev->ad_closesem) != OK)
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{
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ret = -errno;
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}
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else
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{
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/* Decrement the references to the driver. If the reference count will
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* decrement to 0, then uninitialize the driver.
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*/
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if (dev->ad_ocount > 1)
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{
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dev->ad_ocount--;
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sem_post(&dev->ad_closesem);
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}
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else
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{
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/* There are no more references to the port */
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dev->ad_ocount = 0;
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/* Free the IRQ and disable the ADC device */
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flags = irqsave(); /* Disable interrupts */
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dev->ad_ops->ao_shutdown(dev); /* Disable the ADC */
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irqrestore(flags);
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sem_post(&dev->ad_closesem);
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}
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}
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return ret;
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}
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/****************************************************************************
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* Name: adc_read
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****************************************************************************/
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static ssize_t adc_read(FAR struct file *filep, FAR char *buffer, size_t buflen)
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{
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FAR struct inode *inode = filep->f_inode;
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FAR struct adc_dev_s *dev = inode->i_private;
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size_t nread;
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irqstate_t flags;
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int ret = 0;
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int msglen;
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avdbg("buflen: %d\n", (int)buflen);
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if (buflen % 5 == 0)
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msglen = 5;
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else if (buflen % 4 == 0)
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msglen = 4;
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else if (buflen % 3 == 0)
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msglen = 3;
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else if (buflen % 2 == 0)
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msglen = 2;
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else if (buflen == 1)
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msglen = 1;
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else
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msglen = 5;
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if (buflen >= msglen)
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{
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/* Interrupts must be disabled while accessing the ad_recv FIFO */
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flags = irqsave();
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while (dev->ad_recv.af_head == dev->ad_recv.af_tail)
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{
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/* The receive FIFO is empty -- was non-blocking mode selected? */
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if (filep->f_oflags & O_NONBLOCK)
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{
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ret = -EAGAIN;
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goto return_with_irqdisabled;
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}
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/* Wait for a message to be received */
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dev->ad_nrxwaiters++;
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ret = sem_wait(&dev->ad_recv.af_sem);
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dev->ad_nrxwaiters--;
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if (ret < 0)
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{
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ret = -errno;
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goto return_with_irqdisabled;
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}
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}
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/* The ad_recv FIFO is not empty. Copy all buffered data that will fit
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* in the user buffer.
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*/
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nread = 0;
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do
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{
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FAR struct adc_msg_s *msg = &dev->ad_recv.af_buffer[dev->ad_recv.af_head];
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/* Will the next message in the FIFO fit into the user buffer? */
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if (nread + msglen > buflen)
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{
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/* No.. break out of the loop now with nread equal to the actual
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* number of bytes transferred.
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*/
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break;
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}
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/* Copy the message to the user buffer */
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if (msglen == 1)
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{
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/* Only one channel,read highest 8-bits */
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buffer[nread] = msg->am_data >> 24;
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}
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else if (msglen == 2)
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{
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/* Only one channel, read highest 16-bits */
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*(int16_t *)&buffer[nread] = msg->am_data >> 16;
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}
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else if (msglen == 3)
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{
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/* Read channel highest 16-bits */
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buffer[nread] = msg->am_channel;
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*(int16_t *)&buffer[nread + 1] = msg->am_data >> 16;
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}
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else if (msglen == 4)
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{
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/* read channel highest 24-bits */
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*(int32_t *)&buffer[nread] = msg->am_data;
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buffer[nread] = msg->am_channel;
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}
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else
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{
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/* Read all */
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*(int32_t *)&buffer[nread + 1] = msg->am_data;
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buffer[nread] = msg->am_channel;
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}
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nread += msglen;
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/* Increment the head of the circular message buffer */
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if (++dev->ad_recv.af_head >= CONFIG_ADC_FIFOSIZE)
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{
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dev->ad_recv.af_head = 0;
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}
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}
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while (dev->ad_recv.af_head != dev->ad_recv.af_tail);
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/* All on the messages have bee transferred. Return the number of bytes
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* that were read.
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*/
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ret = nread;
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return_with_irqdisabled:
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irqrestore(flags);
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}
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avdbg("Returning: %d\n", ret);
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return ret;
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}
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/************************************************************************************
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* Name: adc_write
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************************************************************************************/
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static ssize_t adc_write(FAR struct file *filep, FAR const char *buffer, size_t buflen)
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{
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return 0;
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}
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/************************************************************************************
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* Name: adc_ioctl
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************************************************************************************/
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static int adc_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
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{
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FAR struct inode *inode = filep->f_inode;
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FAR struct adc_dev_s *dev = inode->i_private;
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int ret = OK;
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ret = dev->ad_ops->ao_ioctl(dev, cmd, arg);
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return ret;
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}
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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int adc_receive(FAR struct adc_dev_s *dev, uint8_t ch, int32_t data)
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{
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FAR struct adc_fifo_s *fifo = &dev->ad_recv;
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int nexttail;
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int err = -ENOMEM;
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/* Check if adding this new message would over-run the drivers ability to enqueue
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* read data.
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*/
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nexttail = fifo->af_tail + 1;
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if (nexttail >= CONFIG_ADC_FIFOSIZE)
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{
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nexttail = 0;
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}
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/* Refuse the new data if the FIFO is full */
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if (nexttail != fifo->af_head)
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{
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/* Add the new, decoded CAN message at the tail of the FIFO */
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fifo->af_buffer[fifo->af_tail].am_channel = ch;
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fifo->af_buffer[fifo->af_tail].am_data = data;
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/* Increment the tail of the circular buffer */
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fifo->af_tail = nexttail;
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if (dev->ad_nrxwaiters > 0)
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{
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sem_post(&fifo->af_sem);
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}
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err = OK;
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}
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return err;
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}
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int adc_register(FAR const char *path, FAR struct adc_dev_s *dev)
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{
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/* Initialize the ADC device structure */
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dev->ad_ocount = 0;
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sem_init(&dev->ad_recv.af_sem, 0, 0);
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sem_init(&dev->ad_closesem, 0, 1);
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dev->ad_ops->ao_reset(dev);
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return register_driver(path, &adc_fops, 0444, dev);
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}
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