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- /****************************************************************************
- * drivers/input/djoystick.c
- *
- * Licensed to the Apache Software Foundation (ASF) under one or more
- * contributor license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership. The
- * ASF licenses this file to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance with the
- * License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
- * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
- * License for the specific language governing permissions and limitations
- * under the License.
- *
- ****************************************************************************/
- /* This file provides a driver for a standard discrete joystick device. A
- * discrete joystick refers to a joystick that could be implemented entirely
- * with GPIO input pins. So up, down, left, and right are all discrete
- * values like buttons (as opposed to integer values like you might obtain
- * from an analog joystick).
- *
- * The discrete joystick driver exports a standard character driver
- * interface. By convention, the discrete joystick is registered as an input
- * device at /dev/djoyN where N uniquely identifies the driver instance.
- */
- /****************************************************************************
- * Included Files
- ****************************************************************************/
- #include <nuttx/config.h>
- #include <sys/types.h>
- #include <stdbool.h>
- #include <string.h>
- #include <poll.h>
- #include <assert.h>
- #include <errno.h>
- #include <debug.h>
- #include <nuttx/kmalloc.h>
- #include <nuttx/signal.h>
- #include <nuttx/random.h>
- #include <nuttx/fs/fs.h>
- #include <nuttx/input/djoystick.h>
- #include <nuttx/irq.h>
- /****************************************************************************
- * Private Types
- ****************************************************************************/
- /* This structure provides the state of one discrete joystick driver */
- struct djoy_upperhalf_s
- {
- /* Saved binding to the lower half discrete joystick driver */
- FAR const struct djoy_lowerhalf_s *du_lower;
- djoy_buttonset_t du_enabled; /* Set of currently enabled button interrupts */
- djoy_buttonset_t du_sample; /* Last sampled button states */
- sem_t du_exclsem; /* Supports exclusive access to the device */
- /* The following is a singly linked list of open references to the
- * joystick device.
- */
- FAR struct djoy_open_s *du_open;
- };
- /* This structure describes the state of one open joystick driver instance */
- struct djoy_open_s
- {
- /* Supports a singly linked list */
- FAR struct djoy_open_s *do_flink;
- /* The following will be true if we are closing */
- volatile bool do_closing;
- /* Joystick event notification information */
- pid_t do_pid;
- struct djoy_notify_s do_notify;
- struct sigwork_s do_work;
- /* Poll event information */
- struct djoy_pollevents_s do_pollevents;
- /* The following is a list if poll structures of threads waiting for
- * driver events.
- */
- FAR struct pollfd *do_fds[CONFIG_INPUT_DJOYSTICK_NPOLLWAITERS];
- };
- /****************************************************************************
- * Private Function Prototypes
- ****************************************************************************/
- /* Semaphore helpers */
- static inline int djoy_takesem(sem_t *sem);
- #define djoy_givesem(s) nxsem_post(s);
- /* Sampling and Interrupt handling */
- static void djoy_enable(FAR struct djoy_upperhalf_s *priv);
- static void djoy_interrupt(FAR const struct djoy_lowerhalf_s *lower,
- FAR void *arg);
- /* Sampling */
- static void djoy_sample(FAR struct djoy_upperhalf_s *priv);
- /* Character driver methods */
- static int djoy_open(FAR struct file *filep);
- static int djoy_close(FAR struct file *filep);
- static ssize_t djoy_read(FAR struct file *filep, FAR char *buffer,
- size_t buflen);
- static int djoy_ioctl(FAR struct file *filep, int cmd,
- unsigned long arg);
- static int djoy_poll(FAR struct file *filep, FAR struct pollfd *fds,
- bool setup);
- /****************************************************************************
- * Private Data
- ****************************************************************************/
- static const struct file_operations djoy_fops =
- {
- djoy_open, /* open */
- djoy_close, /* close */
- djoy_read, /* read */
- 0, /* write */
- 0, /* seek */
- djoy_ioctl, /* ioctl */
- djoy_poll /* poll */
- };
- /****************************************************************************
- * Private Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: djoy_takesem
- ****************************************************************************/
- static inline int djoy_takesem(sem_t *sem)
- {
- return nxsem_wait(sem);
- }
- /****************************************************************************
- * Name: djoy_enable
- ****************************************************************************/
- static void djoy_enable(FAR struct djoy_upperhalf_s *priv)
- {
- FAR const struct djoy_lowerhalf_s *lower;
- FAR struct djoy_open_s *opriv;
- djoy_buttonset_t press;
- djoy_buttonset_t release;
- irqstate_t flags;
- int i;
- DEBUGASSERT(priv);
- lower = priv->du_lower;
- DEBUGASSERT(lower);
- /* This routine is called both task level and interrupt level, so
- * interrupts must be disabled.
- */
- flags = enter_critical_section();
- /* Visit each opened reference to the device */
- press = 0;
- release = 0;
- for (opriv = priv->du_open; opriv; opriv = opriv->do_flink)
- {
- /* Are there any poll waiters? */
- for (i = 0; i < CONFIG_INPUT_DJOYSTICK_NPOLLWAITERS; i++)
- {
- if (opriv->do_fds[i])
- {
- /* Yes.. OR in the poll event buttons */
- press |= opriv->do_pollevents.dp_press;
- release |= opriv->do_pollevents.dp_release;
- break;
- }
- }
- /* OR in the signal events */
- press |= opriv->do_notify.dn_press;
- release |= opriv->do_notify.dn_release;
- }
- /* Enable/disable button interrupts */
- DEBUGASSERT(lower->dl_enable);
- if (press != 0 || release != 0)
- {
- /* Enable interrupts with the new button set */
- lower->dl_enable(lower, press, release,
- (djoy_interrupt_t)djoy_interrupt, priv);
- }
- else
- {
- /* Disable further interrupts */
- lower->dl_enable(lower, 0, 0, NULL, NULL);
- }
- leave_critical_section(flags);
- }
- /****************************************************************************
- * Name: djoy_interrupt
- ****************************************************************************/
- static void djoy_interrupt(FAR const struct djoy_lowerhalf_s *lower,
- FAR void *arg)
- {
- FAR struct djoy_upperhalf_s *priv = (FAR struct djoy_upperhalf_s *)arg;
- DEBUGASSERT(priv);
- /* Process the next sample */
- djoy_sample(priv);
- }
- /****************************************************************************
- * Name: djoy_sample
- ****************************************************************************/
- static void djoy_sample(FAR struct djoy_upperhalf_s *priv)
- {
- FAR const struct djoy_lowerhalf_s *lower;
- FAR struct djoy_open_s *opriv;
- djoy_buttonset_t sample;
- djoy_buttonset_t change;
- djoy_buttonset_t press;
- djoy_buttonset_t release;
- irqstate_t flags;
- int i;
- DEBUGASSERT(priv);
- lower = priv->du_lower;
- DEBUGASSERT(lower);
- /* This routine is called both task level and interrupt level, so
- * interrupts must be disabled.
- */
- flags = enter_critical_section();
- /* Sample the new button state */
- DEBUGASSERT(lower->dl_sample);
- sample = lower->dl_sample(lower);
- add_ui_randomness(sample);
- /* Determine which buttons have been newly pressed and which have been
- * newly released.
- */
- change = sample ^ priv->du_sample;
- press = change & sample;
- DEBUGASSERT(lower->dl_supported);
- release = change & (lower->dl_supported(lower) & ~sample);
- /* Visit each opened reference to the device */
- for (opriv = priv->du_open; opriv; opriv = opriv->do_flink)
- {
- /* Have any poll events occurred? */
- if ((press & opriv->do_pollevents.dp_press) != 0 ||
- (release & opriv->do_pollevents.dp_release) != 0)
- {
- /* Yes.. Notify all waiters */
- for (i = 0; i < CONFIG_INPUT_DJOYSTICK_NPOLLWAITERS; i++)
- {
- FAR struct pollfd *fds = opriv->do_fds[i];
- if (fds)
- {
- fds->revents |= (fds->events & POLLIN);
- if (fds->revents != 0)
- {
- iinfo("Report events: %02x\n", fds->revents);
- nxsem_post(fds->sem);
- }
- }
- }
- }
- /* Have any signal events occurred? */
- if ((press & opriv->do_notify.dn_press) != 0 ||
- (release & opriv->do_notify.dn_release) != 0)
- {
- /* Yes.. Signal the waiter */
- opriv->do_notify.dn_event.sigev_value.sival_int = sample;
- nxsig_notification(opriv->do_pid, &opriv->do_notify.dn_event,
- SI_QUEUE, &opriv->do_work);
- }
- }
- /* Enable/disable interrupt handling */
- djoy_enable(priv);
- priv->du_sample = sample;
- leave_critical_section(flags);
- }
- /****************************************************************************
- * Name: djoy_open
- ****************************************************************************/
- static int djoy_open(FAR struct file *filep)
- {
- FAR struct inode *inode;
- FAR struct djoy_upperhalf_s *priv;
- FAR struct djoy_open_s *opriv;
- FAR const struct djoy_lowerhalf_s *lower;
- djoy_buttonset_t supported;
- int ret;
- DEBUGASSERT(filep && filep->f_inode);
- inode = filep->f_inode;
- DEBUGASSERT(inode->i_private);
- priv = (FAR struct djoy_upperhalf_s *)inode->i_private;
- /* Get exclusive access to the driver structure */
- ret = djoy_takesem(&priv->du_exclsem);
- if (ret < 0)
- {
- ierr("ERROR: djoy_takesem failed: %d\n", ret);
- return ret;
- }
- /* Allocate a new open structure */
- opriv = (FAR struct djoy_open_s *)kmm_zalloc(sizeof(struct djoy_open_s));
- if (!opriv)
- {
- ierr("ERROR: Failed to allocate open structure\n");
- ret = -ENOMEM;
- goto errout_with_sem;
- }
- /* Initialize the open structure */
- lower = priv->du_lower;
- DEBUGASSERT(lower && lower->dl_supported);
- supported = lower->dl_supported(lower);
- opriv->do_pollevents.dp_press = supported;
- opriv->do_pollevents.dp_release = supported;
- /* Attach the open structure to the device */
- opriv->do_flink = priv->du_open;
- priv->du_open = opriv;
- /* Attach the open structure to the file structure */
- filep->f_priv = (FAR void *)opriv;
- ret = OK;
- errout_with_sem:
- djoy_givesem(&priv->du_exclsem);
- return ret;
- }
- /****************************************************************************
- * Name: djoy_close
- ****************************************************************************/
- static int djoy_close(FAR struct file *filep)
- {
- FAR struct inode *inode;
- FAR struct djoy_upperhalf_s *priv;
- FAR struct djoy_open_s *opriv;
- FAR struct djoy_open_s *curr;
- FAR struct djoy_open_s *prev;
- irqstate_t flags;
- bool closing;
- int ret;
- DEBUGASSERT(filep && filep->f_priv && filep->f_inode);
- opriv = filep->f_priv;
- inode = filep->f_inode;
- DEBUGASSERT(inode->i_private);
- priv = (FAR struct djoy_upperhalf_s *)inode->i_private;
- /* Handle an improbable race conditions with the following atomic test
- * and set.
- *
- * This is actually a pretty feeble attempt to handle this. The
- * improbable race condition occurs if two different threads try to
- * close the joystick driver at the same time. The rule: don't do
- * that! It is feeble because we do not really enforce stale pointer
- * detection anyway.
- */
- flags = enter_critical_section();
- closing = opriv->do_closing;
- opriv->do_closing = true;
- leave_critical_section(flags);
- if (closing)
- {
- /* Another thread is doing the close */
- return OK;
- }
- /* Get exclusive access to the driver structure */
- ret = djoy_takesem(&priv->du_exclsem);
- if (ret < 0)
- {
- ierr("ERROR: djoy_takesem failed: %d\n", ret);
- return ret;
- }
- /* Find the open structure in the list of open structures for the device */
- for (prev = NULL, curr = priv->du_open;
- curr && curr != opriv;
- prev = curr, curr = curr->do_flink);
- DEBUGASSERT(curr);
- if (!curr)
- {
- ierr("ERROR: Failed to find open entry\n");
- ret = -ENOENT;
- goto errout_with_exclsem;
- }
- /* Remove the structure from the device */
- if (prev)
- {
- prev->do_flink = opriv->do_flink;
- }
- else
- {
- priv->du_open = opriv->do_flink;
- }
- /* Cancel any pending notification */
- nxsig_cancel_notification(&opriv->do_work);
- /* And free the open structure */
- kmm_free(opriv);
- /* Enable/disable interrupt handling */
- djoy_enable(priv);
- ret = OK;
- errout_with_exclsem:
- djoy_givesem(&priv->du_exclsem);
- return ret;
- }
- /****************************************************************************
- * Name: djoy_read
- ****************************************************************************/
- static ssize_t djoy_read(FAR struct file *filep, FAR char *buffer,
- size_t len)
- {
- FAR struct inode *inode;
- FAR struct djoy_upperhalf_s *priv;
- FAR const struct djoy_lowerhalf_s *lower;
- int ret;
- DEBUGASSERT(filep && filep->f_inode);
- inode = filep->f_inode;
- DEBUGASSERT(inode->i_private);
- priv = (FAR struct djoy_upperhalf_s *)inode->i_private;
- /* Make sure that the buffer is sufficiently large to hold at least one
- * complete sample.
- */
- if (len < sizeof(djoy_buttonset_t))
- {
- ierr("ERROR: buffer too small: %lu\n", (unsigned long)len);
- return -EINVAL;
- }
- /* Get exclusive access to the driver structure */
- ret = djoy_takesem(&priv->du_exclsem);
- if (ret < 0)
- {
- ierr("ERROR: djoy_takesem failed: %d\n", ret);
- return ret;
- }
- /* Read and return the current state of the joystick buttons */
- lower = priv->du_lower;
- DEBUGASSERT(lower && lower->dl_sample);
- priv->du_sample = lower->dl_sample(lower);
- *(FAR djoy_buttonset_t *)buffer = priv->du_sample;
- ret = sizeof(djoy_buttonset_t);
- djoy_givesem(&priv->du_exclsem);
- return (ssize_t)ret;
- }
- /****************************************************************************
- * Name: djoy_ioctl
- ****************************************************************************/
- static int djoy_ioctl(FAR struct file *filep, int cmd, unsigned long arg)
- {
- FAR struct inode *inode;
- FAR struct djoy_upperhalf_s *priv;
- FAR struct djoy_open_s *opriv;
- FAR const struct djoy_lowerhalf_s *lower;
- int ret;
- DEBUGASSERT(filep && filep->f_priv && filep->f_inode);
- opriv = filep->f_priv;
- inode = filep->f_inode;
- DEBUGASSERT(inode->i_private);
- priv = (FAR struct djoy_upperhalf_s *)inode->i_private;
- /* Get exclusive access to the driver structure */
- ret = djoy_takesem(&priv->du_exclsem);
- if (ret < 0)
- {
- ierr("ERROR: djoy_takesem failed: %d\n", ret);
- return ret;
- }
- /* Handle the ioctl command */
- ret = -EINVAL;
- switch (cmd)
- {
- /* Command: DJOYIOC_SUPPORTED
- * Description: Report the set of button events supported by the
- * hardware;
- * Argument: A pointer to writeable integer value in which to return
- * the set of supported buttons.
- * Return: Zero (OK) on success. Minus one will be returned on
- * failure with the errno value set appropriately.
- */
- case DJOYIOC_SUPPORTED:
- {
- FAR int *supported = (FAR int *)((uintptr_t)arg);
- if (supported)
- {
- lower = priv->du_lower;
- DEBUGASSERT(lower && lower->dl_supported);
- *supported = (int)lower->dl_supported(lower);
- ret = OK;
- }
- }
- break;
- /* Command: DJOYIOC_POLLEVENTS
- * Description: Specify the set of button events that can cause a poll()
- * to awaken. The default is all button depressions and
- * all button releases (all supported buttons);
- * Argument: A read-only pointer to an instance of struct
- * djoy_pollevents_s
- * Return: Zero (OK) on success. Minus one will be returned on
- * failure with the errno value set appropriately.
- */
- case DJOYIOC_POLLEVENTS:
- {
- FAR struct djoy_pollevents_s *pollevents =
- (FAR struct djoy_pollevents_s *)((uintptr_t)arg);
- if (pollevents)
- {
- /* Save the poll events */
- opriv->do_pollevents.dp_press = pollevents->dp_press;
- opriv->do_pollevents.dp_release = pollevents->dp_release;
- /* Enable/disable interrupt handling */
- djoy_enable(priv);
- ret = OK;
- }
- }
- break;
- /* Command: DJOYIOC_REGISTER
- * Description: Register to receive a signal whenever there is a change
- * in any of the joystick discrete inputs. This feature,
- * of course, depends upon interrupt GPIO support from the
- * platform.
- * Argument: A read-only pointer to an instance of struct
- * djoy_notify_s
- * Return: Zero (OK) on success. Minus one will be returned on
- * failure with the errno value set appropriately.
- */
- case DJOYIOC_REGISTER:
- {
- FAR struct djoy_notify_s *notify =
- (FAR struct djoy_notify_s *)((uintptr_t)arg);
- if (notify)
- {
- /* Save the notification events */
- opriv->do_notify.dn_press = notify->dn_press;
- opriv->do_notify.dn_release = notify->dn_release;
- opriv->do_notify.dn_event = notify->dn_event;
- opriv->do_pid = getpid();
- /* Enable/disable interrupt handling */
- djoy_enable(priv);
- ret = OK;
- }
- }
- break;
- default:
- ierr("ERROR: Unrecognized command: %d\n", cmd);
- ret = -ENOTTY;
- break;
- }
- djoy_givesem(&priv->du_exclsem);
- return ret;
- }
- /****************************************************************************
- * Name: djoy_poll
- ****************************************************************************/
- static int djoy_poll(FAR struct file *filep, FAR struct pollfd *fds,
- bool setup)
- {
- FAR struct inode *inode;
- FAR struct djoy_upperhalf_s *priv;
- FAR struct djoy_open_s *opriv;
- int ret;
- int i;
- DEBUGASSERT(filep && filep->f_priv && filep->f_inode);
- opriv = filep->f_priv;
- inode = filep->f_inode;
- DEBUGASSERT(inode->i_private);
- priv = (FAR struct djoy_upperhalf_s *)inode->i_private;
- /* Get exclusive access to the driver structure */
- ret = djoy_takesem(&priv->du_exclsem);
- if (ret < 0)
- {
- ierr("ERROR: djoy_takesem failed: %d\n", ret);
- return ret;
- }
- /* Are we setting up the poll? Or tearing it down? */
- if (setup)
- {
- /* This is a request to set up the poll. Find an available
- * slot for the poll structure reference
- */
- for (i = 0; i < CONFIG_INPUT_DJOYSTICK_NPOLLWAITERS; i++)
- {
- /* Find an available slot */
- if (!opriv->do_fds[i])
- {
- /* Bind the poll structure and this slot */
- opriv->do_fds[i] = fds;
- fds->priv = &opriv->do_fds[i];
- break;
- }
- }
- if (i >= CONFIG_INPUT_DJOYSTICK_NPOLLWAITERS)
- {
- ierr("ERROR: Too man poll waiters\n");
- fds->priv = NULL;
- ret = -EBUSY;
- goto errout_with_dusem;
- }
- }
- else if (fds->priv)
- {
- /* This is a request to tear down the poll. */
- FAR struct pollfd **slot = (FAR struct pollfd **)fds->priv;
- #ifdef CONFIG_DEBUG_FEATURES
- if (!slot)
- {
- ierr("ERROR: Poll slot not found\n");
- ret = -EIO;
- goto errout_with_dusem;
- }
- #endif
- /* Remove all memory of the poll setup */
- *slot = NULL;
- fds->priv = NULL;
- }
- errout_with_dusem:
- djoy_givesem(&priv->du_exclsem);
- return ret;
- }
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: djoy_register
- *
- * Description:
- * Bind the lower half discrete joystick driver to an instance of the
- * upper half discrete joystick driver and register the composite character
- * driver as the specific device.
- *
- * Input Parameters:
- * devname - The name of the discrete joystick device to be registers.
- * This should be a string of the form "/priv/djoyN" where N is the
- * minor device number.
- * lower - An instance of the platform-specific discrete joystick lower
- * half driver.
- *
- * Returned Value:
- * Zero (OK) is returned on success. Otherwise a negated errno value is
- * returned to indicate the nature of the failure.
- *
- ****************************************************************************/
- int djoy_register(FAR const char *devname,
- FAR const struct djoy_lowerhalf_s *lower)
- {
- FAR struct djoy_upperhalf_s *priv;
- int ret;
- DEBUGASSERT(devname && lower);
- /* Allocate a new djoystick driver instance */
- priv = (FAR struct djoy_upperhalf_s *)
- kmm_zalloc(sizeof(struct djoy_upperhalf_s));
- if (!priv)
- {
- ierr("ERROR: Failed to allocate device structure\n");
- return -ENOMEM;
- }
- /* Make sure that all djoystick interrupts are disabled */
- DEBUGASSERT(lower->dl_enable);
- lower->dl_enable(lower, 0, 0, NULL, NULL);
- /* Initialize the new djoystick driver instance */
- priv->du_lower = lower;
- nxsem_init(&priv->du_exclsem, 0, 1);
- DEBUGASSERT(lower->dl_sample);
- priv->du_sample = lower->dl_sample(lower);
- /* And register the djoystick driver */
- ret = register_driver(devname, &djoy_fops, 0666, priv);
- if (ret < 0)
- {
- ierr("ERROR: register_driver failed: %d\n", ret);
- nxsem_destroy(&priv->du_exclsem);
- kmm_free(priv);
- }
- return ret;
- }
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