/**************************************************************************** * drivers/input/nunchuck.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 Nintendo Wii Nunchuck joystick device. * The nunchuck joystick provides X/Y positional data as integer values. * The analog positional data may also be accompanied by discrete button * data. * * The nunchuck joystick driver exports a standard character driver * interface. By convention, the nunchuck joystick is registered as an input * device at /dev/nunchuckN where N uniquely identifies the driver instance. */ /**************************************************************************** * Included Files ****************************************************************************/ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /**************************************************************************** * Private Types ****************************************************************************/ /* This structure provides the state of one nunchuck joystick driver */ struct nunchuck_dev_s { FAR struct i2c_master_s *i2c_dev; /* I2C interface connected to Nunchuck */ nunchuck_buttonset_t nck_sample; /* Last sampled button states */ mutex_t nck_lock; /* Supports exclusive access to the device */ /* The following is a singly linked list of open references to the * joystick device. */ FAR struct nunchuck_open_s *nck_open; }; /* This structure describes the state of one open joystick driver instance */ struct nunchuck_open_s { /* Supports a singly linked list */ FAR struct nunchuck_open_s *nck_flink; /* The following will be true if we are closing */ volatile bool nck_closing; }; /**************************************************************************** * Private Function Prototypes ****************************************************************************/ /* Character driver methods */ static int nunchuck_open(FAR struct file *filep); static int nunchuck_close(FAR struct file *filep); static ssize_t nunchuck_read(FAR struct file *filep, FAR char *buffer, size_t buflen); static int nunchuck_ioctl(FAR struct file *filep, int cmd, unsigned long arg); /* I2C Helpers */ static int nunchuck_i2c_read(FAR struct nunchuck_dev_s *priv, FAR uint8_t *regval, int len); static int nunchuck_i2c_write(FAR struct nunchuck_dev_s *priv, uint8_t const *data, int len); static int nunchuck_sample(FAR struct nunchuck_dev_s *priv, FAR struct nunchuck_sample_s *buffer); /**************************************************************************** * Private Data ****************************************************************************/ static const struct file_operations g_nunchuck_fops = { nunchuck_open, /* open */ nunchuck_close, /* close */ nunchuck_read, /* read */ NULL, /* write */ NULL, /* seek */ nunchuck_ioctl, /* ioctl */ }; /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: nunchuck_i2c_read ****************************************************************************/ static int nunchuck_i2c_read(FAR struct nunchuck_dev_s *priv, FAR uint8_t *regval, int len) { struct i2c_config_s config; int ret = -1; /* Set up the I2C configuration */ config.frequency = NUNCHUCK_I2C_FREQ; config.address = NUNCHUCK_ADDR; config.addrlen = 7; /* Read "len" bytes from regaddr */ ret = i2c_read(priv->i2c_dev, &config, regval, len); if (ret < 0) { ierr ("i2c_read failed: %d\n", ret); return ret; } return OK; } /**************************************************************************** * Name: nunchuck_i2c_write ****************************************************************************/ static int nunchuck_i2c_write(FAR struct nunchuck_dev_s *priv, uint8_t const *data, int len) { struct i2c_config_s config; int ret; /* Set up the I2C configuration */ config.frequency = NUNCHUCK_I2C_FREQ; config.address = NUNCHUCK_ADDR; config.addrlen = 7; /* Write the data */ ret = i2c_write(priv->i2c_dev, &config, data, len); if (ret < 0) { ierr("ERROR: i2c_write failed: %d\n", ret); } return ret; } static int nunchuck_sample(FAR struct nunchuck_dev_s *priv, FAR struct nunchuck_sample_s *buffer) { uint8_t cmd[2]; uint8_t data[6]; static bool initialized; if (!initialized) { /* Start device */ cmd[0] = 0x40; cmd[1] = 0x00; nunchuck_i2c_write(priv, cmd, 2); /* Delay 20ms */ nxsig_usleep(20 * 1000); initialized = true; } /* Prepare to read */ cmd[0] = 0x00; nunchuck_i2c_write(priv, cmd, 1); /* Wait */ nxsig_usleep(1000); /* Read data */ nunchuck_i2c_read(priv, &data[0], 1); /* Wait */ nxsig_usleep(1000); /* Wait */ nxsig_usleep(1000); nunchuck_i2c_read(priv, &data[1], 1); /* Wait */ nxsig_usleep(1000); nunchuck_i2c_read(priv, &data[2], 1); /* Wait */ nxsig_usleep(1000); nunchuck_i2c_read(priv, &data[3], 1); /* Wait */ nxsig_usleep(1000); nunchuck_i2c_read(priv, &data[4], 1); /* Wait */ nxsig_usleep(1000); nunchuck_i2c_read(priv, &data[5], 1); /* Save the sample */ buffer->js_x = (uint16_t) data[0]; buffer->js_y = (uint16_t) data[1]; buffer->acc_x = (uint16_t) data[2]; buffer->acc_y = (uint16_t) data[3]; buffer->acc_z = (uint16_t) data[4]; buffer->nck_buttons = (uint8_t) ((data[5] + 1) & 0x03); iinfo("X: %03d | Y: %03d | AX: %03d AY: %03d AZ: %03d | B: %d\n", data[0], data[1], data[2], data[3], data[4], ((data[5] + 1) & 0x03)); return OK; } /**************************************************************************** * Name: nunchuck_open ****************************************************************************/ static int nunchuck_open(FAR struct file *filep) { FAR struct inode *inode; FAR struct nunchuck_dev_s *priv; FAR struct nunchuck_open_s *opriv; int ret; inode = filep->f_inode; DEBUGASSERT(inode->i_private); priv = inode->i_private; /* Get exclusive access to the driver structure */ ret = nxmutex_lock(&priv->lock); if (ret < 0) { ierr("ERROR: nxmutex_lock failed: %d\n", ret); return ret; } /* Allocate a new open structure */ opriv = (FAR struct nunchuck_open_s *) kmm_zalloc(sizeof(struct nunchuck_open_s)); if (!opriv) { ierr("ERROR: Failed to allocate open structure\n"); ret = -ENOMEM; goto errout_with_lock; } /* Attach the open structure to the device */ opriv->nck_flink = priv->nck_open; priv->nck_open = opriv; /* Attach the open structure to the file structure */ filep->f_priv = (FAR void *)opriv; ret = OK; errout_with_lock: nxmutex_unlock(&priv->lock); return ret; } /**************************************************************************** * Name: nunchuck_close ****************************************************************************/ static int nunchuck_close(FAR struct file *filep) { FAR struct inode *inode; FAR struct nunchuck_dev_s *priv; FAR struct nunchuck_open_s *opriv; FAR struct nunchuck_open_s *curr; FAR struct nunchuck_open_s *prev; irqstate_t flags; bool closing; int ret; DEBUGASSERT(filep->f_priv); opriv = filep->f_priv; inode = filep->f_inode; DEBUGASSERT(inode->i_private); priv = 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->nck_closing; opriv->nck_closing = true; leave_critical_section(flags); if (closing) { /* Another thread is doing the close */ return OK; } /* Get exclusive access to the driver structure */ ret = nxmutex_lock(&priv->lock); if (ret < 0) { ierr("ERROR: nxmutex_lock failed: %d\n", ret); return ret; } /* Find the open structure in the list of open structures for the device */ for (prev = NULL, curr = priv->nck_open; curr && curr != opriv; prev = curr, curr = curr->nck_flink); DEBUGASSERT(curr); if (!curr) { ierr("ERROR: Failed to find open entry\n"); ret = -ENOENT; goto errout_with_lock; } /* Remove the structure from the device */ if (prev) { prev->nck_flink = opriv->nck_flink; } else { priv->nck_open = opriv->nck_flink; } /* And free the open structure */ kmm_free(opriv); ret = OK; errout_with_lock: nxmutex_unlock(&priv->lock); return ret; } /**************************************************************************** * Name: nunchuck_read ****************************************************************************/ static ssize_t nunchuck_read(FAR struct file *filep, FAR char *buffer, size_t len) { FAR struct inode *inode; FAR struct nunchuck_dev_s *priv; int ret; inode = filep->f_inode; DEBUGASSERT(inode->i_private); priv = inode->i_private; /* Make sure that the buffer is sufficiently large to hold at least one * complete sample. * * REVISIT: Should also check buffer alignment. */ if (len < sizeof(struct nunchuck_sample_s)) { ierr("ERROR: buffer too small: %lu\n", (unsigned long)len); return -EINVAL; } /* Get exclusive access to the driver structure */ ret = nxmutex_lock(&priv->lock); if (ret < 0) { ierr("ERROR: nxmutex_lock failed: %d\n", ret); return ret; } /* Read and return the current state of the joystick buttons */ ret = nunchuck_sample(priv, (FAR struct nunchuck_sample_s *)buffer); if (ret >= 0) { ret = sizeof(struct nunchuck_sample_s); } nxmutex_unlock(&priv->lock); return (ssize_t)ret; } /**************************************************************************** * Name: nunchuck_ioctl ****************************************************************************/ static int nunchuck_ioctl(FAR struct file *filep, int cmd, unsigned long arg) { FAR struct inode *inode; FAR struct nunchuck_dev_s *priv; int ret; DEBUGASSERT(filep->f_priv); inode = filep->f_inode; DEBUGASSERT(inode->i_private); priv = inode->i_private; /* Get exclusive access to the driver structure */ ret = nxmutex_lock(&priv->lock); if (ret < 0) { ierr("ERROR: nxmutex_lock failed: %d\n", ret); return ret; } /* Handle the ioctl command */ ret = -EINVAL; switch (cmd) { /* Command: NUNCHUCKIOC_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 NUNCHUCKIOC_SUPPORTED: { FAR int *supported = (FAR int *)((uintptr_t)arg); if (supported) { *supported = (NUNCHUCK_BUTTON_Z_BIT | NUNCHUCK_BUTTON_C_BIT); ret = OK; } } break; default: ierr("ERROR: Unrecognized command: %ld\n", cmd); ret = -ENOTTY; break; } nxmutex_unlock(&priv->lock); return ret; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: nunchuck_register * * Description: * Register the Nunchuck character driver as the specified device. * * Input Parameters: * devname - The name of the Nunchuck joystick device to be registered. * This should be a string of the form "/dev/nunchuckN" where N is the * minor device number. * i2c - An instance of the platform-specific I2C connected to Nunchuck. * * Returned Value: * Zero (OK) is returned on success. Otherwise a negated errno value is * returned to indicate the nature of the failure. * ****************************************************************************/ int nunchuck_register(FAR const char *devname, FAR struct i2c_master_s *i2c) { FAR struct nunchuck_dev_s *priv; int ret; iinfo("Enter\n"); DEBUGASSERT(devname && i2c); /* Allocate a new nunchuck driver instance */ priv = (FAR struct nunchuck_dev_s *) kmm_zalloc(sizeof(struct nunchuck_dev_s)); if (!priv) { ierr("ERROR: Failed to allocate device structure\n"); return -ENOMEM; } /* Save the i2c device */ priv->i2c_dev = i2c; /* Initialize the new nunchuck driver instance */ nxmutex_init(&priv->nck_lock); /* And register the nunchuck driver */ ret = register_driver(devname, &g_nunchuck_fops, 0666, priv); if (ret < 0) { ierr("ERROR: register_driver failed: %d\n", ret); goto errout_with_priv; } return OK; errout_with_priv: nxmutex_destroy(&priv->nck_lock); kmm_free(priv); return ret; }