diff options
Diffstat (limited to 'arch/arm/mach-msm/smd_nmea.c')
| -rw-r--r-- | arch/arm/mach-msm/smd_nmea.c | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/arch/arm/mach-msm/smd_nmea.c b/arch/arm/mach-msm/smd_nmea.c new file mode 100644 index 000000000000..35e1cbdca1e6 --- /dev/null +++ b/arch/arm/mach-msm/smd_nmea.c @@ -0,0 +1,249 @@ +/* Copyright (c) 2008-2009, Code Aurora Forum. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * 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. + * * Neither the name of Code Aurora Forum nor + * the names of its contributors may be used to endorse or promote + * products derived from this software without specific prior written + * permission. + * + * Alternatively, provided that this notice is retained in full, this software + * may be relicensed by the recipient under the terms of the GNU General Public + * License version 2 ("GPL") and only version 2, in which case the provisions of + * the GPL apply INSTEAD OF those given above. If the recipient relicenses the + * software under the GPL, then the identification text in the MODULE_LICENSE + * macro must be changed to reflect "GPLv2" instead of "Dual BSD/GPL". Once a + * recipient changes the license terms to the GPL, subsequent recipients shall + * not relicense under alternate licensing terms, including the BSD or dual + * BSD/GPL terms. In addition, the following license statement immediately + * below and between the words START and END shall also then apply when this + * software is relicensed under the GPL: + * + * START + * + * This program is free software; you can redistribute it and/or modify it under + * the terms of the GNU General Public License version 2 and only version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS + * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more + * details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * END + * + * 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. + * + */ +/* + * SMD NMEA Driver -- Provides GPS NMEA device to SMD port interface. + * + */ + +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/cdev.h> +#include <linux/device.h> +#include <linux/wait.h> +#include <linux/sched.h> +#include <linux/miscdevice.h> +#include <linux/workqueue.h> +#include <linux/uaccess.h> + +#include <mach/msm_smd.h> + +#define MAX_BUF_SIZE 200 + +static DEFINE_MUTEX(nmea_ch_lock); +static DEFINE_MUTEX(nmea_rx_buf_lock); + +static DECLARE_WAIT_QUEUE_HEAD(nmea_wait_queue); + +struct nmea_device_t { + struct miscdevice misc; + + struct smd_channel *ch; + + unsigned char rx_buf[MAX_BUF_SIZE]; + unsigned int bytes_read; +}; + +struct nmea_device_t *nmea_devp; + +static void nmea_work_func(struct work_struct *ws) +{ + int sz; + + for (;;) { + sz = smd_cur_packet_size(nmea_devp->ch); + if (sz == 0) + break; + if (sz > smd_read_avail(nmea_devp->ch)) + break; + if (sz > MAX_BUF_SIZE) { + smd_read(nmea_devp->ch, 0, sz); + continue; + } + + mutex_lock(&nmea_rx_buf_lock); + if (smd_read(nmea_devp->ch, nmea_devp->rx_buf, sz) != sz) { + mutex_unlock(&nmea_rx_buf_lock); + printk(KERN_ERR "nmea: not enough data?!\n"); + continue; + } + nmea_devp->bytes_read = sz; + mutex_unlock(&nmea_rx_buf_lock); + wake_up_interruptible(&nmea_wait_queue); + } +} + +struct workqueue_struct *nmea_wq; +static DECLARE_WORK(nmea_work, nmea_work_func); + +static void nmea_notify(void *priv, unsigned event) +{ + switch (event) { + case SMD_EVENT_DATA: { + int sz; + sz = smd_cur_packet_size(nmea_devp->ch); + if ((sz > 0) && (sz <= smd_read_avail(nmea_devp->ch))) + queue_work(nmea_wq, &nmea_work); + break; + } + case SMD_EVENT_OPEN: + printk(KERN_INFO "nmea: smd opened\n"); + break; + case SMD_EVENT_CLOSE: + printk(KERN_INFO "nmea: smd closed\n"); + break; + } +} + +static ssize_t nmea_read(struct file *fp, char __user *buf, + size_t count, loff_t *pos) +{ + int r; + int bytes_read; + + r = wait_event_interruptible(nmea_wait_queue, + nmea_devp->bytes_read); + if (r < 0) { + /* qualify error message */ + if (r != -ERESTARTSYS) { + /* we get this anytime a signal comes in */ + printk(KERN_ERR "ERROR:%s:%i:%s: " + "wait_event_interruptible ret %i\n", + __FILE__, + __LINE__, + __func__, + r + ); + } + return r; + } + + mutex_lock(&nmea_rx_buf_lock); + bytes_read = nmea_devp->bytes_read; + nmea_devp->bytes_read = 0; + r = copy_to_user(buf, nmea_devp->rx_buf, bytes_read); + mutex_unlock(&nmea_rx_buf_lock); + + if (r > 0) { + printk(KERN_ERR "ERROR:%s:%i:%s: " + "copy_to_user could not copy %i bytes.\n", + __FILE__, + __LINE__, + __func__, + r); + return r; + } + + return bytes_read; +} + +static int nmea_open(struct inode *ip, struct file *fp) +{ + int r = 0; + + mutex_lock(&nmea_ch_lock); + if (nmea_devp->ch == 0) + r = smd_open("GPSNMEA", &nmea_devp->ch, nmea_devp, nmea_notify); + mutex_unlock(&nmea_ch_lock); + + return r; +} + +static int nmea_release(struct inode *ip, struct file *fp) +{ + int r = 0; + + mutex_lock(&nmea_ch_lock); + if (nmea_devp->ch != 0) { + r = smd_close(nmea_devp->ch); + nmea_devp->ch = 0; + } + mutex_unlock(&nmea_ch_lock); + + return r; +} + +static const struct file_operations nmea_fops = { + .owner = THIS_MODULE, + .read = nmea_read, + .open = nmea_open, + .release = nmea_release, +}; + +static struct nmea_device_t nmea_device = { + .misc = { + .minor = MISC_DYNAMIC_MINOR, + .name = "nmea", + .fops = &nmea_fops, + } +}; + +static void __exit nmea_exit(void) +{ + destroy_workqueue(nmea_wq); + misc_deregister(&nmea_device.misc); +} + +static int __init nmea_init(void) +{ + int ret; + + nmea_device.bytes_read = 0; + nmea_devp = &nmea_device; + + nmea_wq = create_singlethread_workqueue("nmea"); + if (nmea_wq == 0) + return -ENOMEM; + + ret = misc_register(&nmea_device.misc); + return ret; +} + +module_init(nmea_init); +module_exit(nmea_exit); + +MODULE_DESCRIPTION("MSM Shared Memory NMEA Driver"); +MODULE_LICENSE("GPL v2"); |