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author | patacongo <patacongo@7fd9a85b-ad96-42d3-883c-3090e2eb8679> | 2012-02-14 15:32:57 +0000 |
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committer | patacongo <patacongo@7fd9a85b-ad96-42d3-883c-3090e2eb8679> | 2012-02-14 15:32:57 +0000 |
commit | 2bc230a0d6b25d3ac140f3acfbfcd6ea478c5d8b (patch) | |
tree | edf22faa8e6f3919fe00791bec725da56a9c88b4 /nuttx/drivers | |
parent | 1cc7e843bc250baff2f2864c707cb3e5e574de87 (diff) | |
download | px4-firmware-2bc230a0d6b25d3ac140f3acfbfcd6ea478c5d8b.tar.gz px4-firmware-2bc230a0d6b25d3ac140f3acfbfcd6ea478c5d8b.tar.bz2 px4-firmware-2bc230a0d6b25d3ac140f3acfbfcd6ea478c5d8b.zip |
Add an infrastructure to support a generic quadrature encoder driver
git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@4390 7fd9a85b-ad96-42d3-883c-3090e2eb8679
Diffstat (limited to 'nuttx/drivers')
-rw-r--r-- | nuttx/drivers/sensors/Make.defs | 6 | ||||
-rw-r--r-- | nuttx/drivers/sensors/qencoder.c | 396 |
2 files changed, 402 insertions, 0 deletions
diff --git a/nuttx/drivers/sensors/Make.defs b/nuttx/drivers/sensors/Make.defs index bda3e8ed3..bd28ba070 100644 --- a/nuttx/drivers/sensors/Make.defs +++ b/nuttx/drivers/sensors/Make.defs @@ -44,6 +44,12 @@ ifeq ($(CONFIG_I2C_LM75),y) endif endif +# Quadrature encoder upper half + +ifeq ($(CONFIG_QENCODER),y) + CSRCS += qencoder.c +endif + # Include sensor driver build support DEPPATH += --dep-path sensors diff --git a/nuttx/drivers/sensors/qencoder.c b/nuttx/drivers/sensors/qencoder.c new file mode 100644 index 000000000..edbe8255c --- /dev/null +++ b/nuttx/drivers/sensors/qencoder.c @@ -0,0 +1,396 @@ +/**************************************************************************** + * drivers/sensors/qencoder.c + * + * Copyright (C) 2012 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/**************************************************************************** + * Compilation Switches + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <sys/types.h> +#include <stdint.h> +#include <stdbool.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <semaphore.h> +#include <fcntl.h> +#include <assert.h> +#include <errno.h> +#include <debug.h> + +#include <nuttx/fs.h> +#include <nuttx/arch.h> +#include <nuttx/sensors/qencoder.h> + +#include <arch/irq.h> + +#ifdef CONFIG_QENCODER + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ +/* Debug ********************************************************************/ +/* Non-standard debug that may be enabled just for testing PWM */ + +#ifdef CONFIG_DEBUG_QENCODER +# define qedbg dbg +# define qevdbg vdbg +# define qelldbg lldbg +# define qellvdbg llvdbg +#else +# define qedbg(x...) +# define qevdbg(x...) +# define qelldbg(x...) +# define qellvdbg(x...) +#endif + +/**************************************************************************** + * Private Type Definitions + ****************************************************************************/ + +/* This structure describes the state of the upper half drivere */ + +struct qe_upperhalf_s +{ + uint8_t crefs; /* The number of times the device has been opened */ + sem_t exclsem; /* Supports mutual exclusion */ + FAR struct qe_lowerhalf_s *lower; /* lower-half state */ +}; + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ + +static int qe_open(FAR struct file *filep); +static int qe_close(FAR struct file *filep); +static ssize_t qe_read(FAR struct file *filep, FAR char *buffer, size_t buflen); +static ssize_t qe_write(FAR struct file *filep, FAR const char *buffer, size_t buflen); +static int qe_ioctl(FAR struct file *filep, int cmd, unsigned long arg); + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +static const struct file_operations g_qeops = +{ + qe_open, /* open */ + qe_close, /* close */ + qe_read, /* read */ + qe_write, /* write */ + 0, /* seek */ + qe_ioctl /* ioctl */ +#ifndef CONFIG_DISABLE_POLL + , 0 /* poll */ +#endif +}; + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/************************************************************************************ + * Name: qe_open + * + * Description: + * This function is called whenever the PWM device is opened. + * + ************************************************************************************/ + +static int qe_open(FAR struct file *filep) +{ + FAR struct inode *inode = filep->f_inode; + FAR struct qe_upperhalf_s *upper = inode->i_private; + uint8_t tmp; + int ret; + + qevdbg("crefs: %d\n", upper->crefs); + + /* Get exclusive access to the device structures */ + + ret = sem_wait(&upper->exclsem); + if (ret < 0) + { + ret = -errno; + goto errout; + } + + /* 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 = upper->crefs + 1; + if (tmp == 0) + { + /* More than 255 opens; uint8_t overflows to zero */ + + ret = -EMFILE; + goto errout_with_sem; + } + + /* Check if this is the first time that the driver has been opened. */ + + if (tmp == 1) + { + FAR struct qe_lowerhalf_s *lower = upper->lower; + + /* Yes.. perform one time hardware initialization. */ + + DEBUGASSERT(lower->ops->setup != NULL); + qevdbg("calling setup\n"); + + ret = lower->ops->setup(lower); + if (ret < 0) + { + goto errout_with_sem; + } + } + + /* Save the new open count on success */ + + upper->crefs = tmp; + ret = OK; + +errout_with_sem: + sem_post(&upper->exclsem); + +errout: + return ret; +} + +/************************************************************************************ + * Name: qe_close + * + * Description: + * This function is called when the PWM device is closed. + * + ************************************************************************************/ + +static int qe_close(FAR struct file *filep) +{ + FAR struct inode *inode = filep->f_inode; + FAR struct qe_upperhalf_s *upper = inode->i_private; + int ret; + + qevdbg("crefs: %d\n", upper->crefs); + + /* Get exclusive access to the device structures */ + + ret = sem_wait(&upper->exclsem); + if (ret < 0) + { + ret = -errno; + goto errout; + } + + /* Decrement the references to the driver. If the reference count will + * decrement to 0, then uninitialize the driver. + */ + + if (upper->crefs > 1) + { + upper->crefs--; + } + else + { + FAR struct qe_lowerhalf_s *lower = upper->lower; + + /* There are no more references to the port */ + + upper->crefs = 0; + + /* Disable the PWM device */ + + DEBUGASSERT(lower->ops->shutdown != NULL); + qevdbg("calling shutdown: %d\n"); + + lower->ops->shutdown(lower); + } + ret = OK; + +//errout_with_sem: + sem_post(&upper->exclsem); + +errout: + return ret; +} + +/************************************************************************************ + * Name: qe_read + * + * Description: + * A dummy read method. This is provided only to satsify the VFS layer. + * + ************************************************************************************/ + +static ssize_t qe_read(FAR struct file *filep, FAR char *buffer, size_t buflen) +{ + /* Return zero -- usually meaning end-of-file */ + + return 0; +} + +/************************************************************************************ + * Name: qe_write + * + * Description: + * A dummy write method. This is provided only to satsify the VFS layer. + * + ************************************************************************************/ + +static ssize_t qe_write(FAR struct file *filep, FAR const char *buffer, size_t buflen) +{ + /* Return a failure */ + + return -EPERM; +} + +/************************************************************************************ + * Name: qe_ioctl + * + * Description: + * The standard ioctl method. This is where ALL of the PWM work is done. + * + ************************************************************************************/ + +static int qe_ioctl(FAR struct file *filep, int cmd, unsigned long arg) +{ + FAR struct inode *inode = filep->f_inode; + FAR struct qe_upperhalf_s *upper = inode->i_private; + FAR struct qe_lowerhalf_s *lower = upper->lower; + int ret; + + qevdbg("cmd: %d arg: %ld\n", cmd, arg); + DEBUGASSERT(upper && lower); + + /* Get exclusive access to the device structures */ + + ret = sem_wait(&upper->exclsem); + if (ret < 0) + { + return ret; + } + + /* Handle built-in ioctl commands */ + + switch (cmd) + { + /* QEIOC_POSITION - Get the current position from the encoder. + * Argument: int32_t pointer to the location to return the position. + */ + + case QEIOC_POSITION: + { + FAR int32_t *ptr = (FAR int32_t *)((uintptr_t)arg); + DEBUGASSERT(lower->ops->position != NULL && ptr); + ret = lower->ops->position(lower, ptr); + } + break; + + /* QEIOC_RESET - Reset the position to zero. + * Argument: None + */ + + case QEIOC_RESET: + { + DEBUGASSERT(lower->ops->reset != NULL); + ret = lower->ops->reset(lower); + } + break; + + /* Any unrecognized IOCTL commands might be platform-specific ioctl commands */ + + default: + { + qevdbg("Forwarding unrecognized cmd: %d arg: %ld\n", cmd, arg); + DEBUGASSERT(lower->ops->ioctl != NULL); + ret = lower->ops->ioctl(lower, cmd, arg); + } + break; + } + + sem_post(&upper->exclsem); + return ret; +} + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: qe_register + * + * Description: + * Register the Quadrature Encoder lower half device as 'devpath' + * + * Input Parameters: + * devpath - The full path to the driver to register. E.g., "/dev/qe0" + * lower - An instance of the lower half interface + * + * Returned Value: + * Zero (OK) on success; a negated errno value on failure. + * + ****************************************************************************/ + +int qe_register(FAR const char *devpath, FAR struct qe_lowerhalf_s *lower) +{ + FAR struct qe_upperhalf_s *upper; + + /* Allocate the upper-half data structure */ + + upper = (FAR struct qe_upperhalf_s *)zalloc(sizeof(struct qe_upperhalf_s)); + if (!upper) + { + qedbg("Allocation failed\n"); + return -ENOMEM; + } + + /* Initialize the PWM device structure (it was already zeroed by zalloc()) */ + + sem_init(&upper->exclsem, 0, 1); + upper->lower = lower; + + /* Register the PWM device */ + + qevdbg("Registering %s\n", devpath); + return register_driver(devpath, &g_qeops, 0666, upper); +} + +#endif /* CONFIG_QENCODER */ |