diff options
Diffstat (limited to 'drivers/char/msm_smd_pkt.c')
| -rw-r--r-- | drivers/char/msm_smd_pkt.c | 466 |
1 files changed, 466 insertions, 0 deletions
diff --git a/drivers/char/msm_smd_pkt.c b/drivers/char/msm_smd_pkt.c new file mode 100644 index 00000000000..b6f8a65c996 --- /dev/null +++ b/drivers/char/msm_smd_pkt.c @@ -0,0 +1,466 @@ +/* Copyright (c) 2008-2010, Code Aurora Forum. All rights reserved. + * + * 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. + * + */ +/* + * SMD Packet Driver -- Provides userspace interface to SMD packet ports. + */ + +#include <linux/slab.h> +#include <linux/cdev.h> +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/device.h> +#include <linux/sched.h> +#include <linux/mutex.h> +#include <linux/delay.h> +#include <linux/uaccess.h> +#include <linux/workqueue.h> +#include <linux/poll.h> + +#include <mach/msm_smd.h> + +#define NUM_SMD_PKT_PORTS 9 +#define DEVICE_NAME "smdpkt" +#define MAX_BUF_SIZE 2048 + +struct smd_pkt_dev { + struct cdev cdev; + struct device *devicep; + + struct smd_channel *ch; + int open_count; + struct mutex ch_lock; + struct mutex rx_lock; + struct mutex tx_lock; + wait_queue_head_t ch_read_wait_queue; + wait_queue_head_t ch_opened_wait_queue; + + int i; + + unsigned char tx_buf[MAX_BUF_SIZE]; + unsigned char rx_buf[MAX_BUF_SIZE]; + int remote_open; + +} *smd_pkt_devp[NUM_SMD_PKT_PORTS]; + +struct class *smd_pkt_classp; +static dev_t smd_pkt_number; + +static int msm_smd_pkt_debug_enable; +module_param_named(debug_enable, msm_smd_pkt_debug_enable, + int, S_IRUGO | S_IWUSR | S_IWGRP); + +#ifdef DEBUG +#define D_DUMP_BUFFER(prestr, cnt, buf) do { \ + int i; \ + if (msm_smd_pkt_debug_enable) { \ + pr_debug("%s", prestr); \ + for (i = 0; i < cnt; i++) \ + pr_debug("%.2x", buf[i]); \ + pr_debug("\n"); \ + } \ + } while (0) +#else +#define D_DUMP_BUFFER(prestr, cnt, buf) do {} while (0) +#endif + +#ifdef DEBUG +#define DBG(x...) do { \ + if (msm_smd_pkt_debug_enable) \ + pr_debug(x); \ + } while (0) +#else +#define DBG(x...) do {} while (0) +#endif + +static void check_and_wakeup_reader(struct smd_pkt_dev *smd_pkt_devp) +{ + int sz; + + if (!smd_pkt_devp || !smd_pkt_devp->ch) + return; + + sz = smd_cur_packet_size(smd_pkt_devp->ch); + if (sz == 0) { + DBG("no packet\n"); + return; + } + if (sz > smd_read_avail(smd_pkt_devp->ch)) { + DBG("incomplete packet\n"); + return; + } + + DBG("waking up reader\n"); + wake_up_interruptible(&smd_pkt_devp->ch_read_wait_queue); +} + +static int smd_pkt_read(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + int r, bytes_read; + struct smd_pkt_dev *smd_pkt_devp; + struct smd_channel *chl; + + DBG("read %d bytes\n", count); + if (count > MAX_BUF_SIZE) + return -EINVAL; + + smd_pkt_devp = file->private_data; + if (!smd_pkt_devp || !smd_pkt_devp->ch) + return -EINVAL; + + chl = smd_pkt_devp->ch; +wait_for_packet: + r = wait_event_interruptible(smd_pkt_devp->ch_read_wait_queue, + (smd_cur_packet_size(chl) > 0 && + smd_read_avail(chl) >= + smd_cur_packet_size(chl))); + + if (r < 0) { + if (r != -ERESTARTSYS) + pr_err("wait returned %d\n", r); + return r; + } + + mutex_lock(&smd_pkt_devp->rx_lock); + + bytes_read = smd_cur_packet_size(smd_pkt_devp->ch); + if (bytes_read == 0 || + bytes_read < smd_read_avail(smd_pkt_devp->ch)) { + mutex_unlock(&smd_pkt_devp->rx_lock); + DBG("Nothing to read\n"); + goto wait_for_packet; + } + + if (bytes_read > count) { + mutex_unlock(&smd_pkt_devp->rx_lock); + pr_info("packet size %d > buffer size %d", bytes_read, count); + return -EINVAL; + } + + r = smd_read(smd_pkt_devp->ch, smd_pkt_devp->rx_buf, bytes_read); + if (r != bytes_read) { + mutex_unlock(&smd_pkt_devp->rx_lock); + pr_err("smd_read failed to read %d bytes: %d\n", bytes_read, r); + return -EIO; + } + + D_DUMP_BUFFER("read: ", bytes_read, smd_pkt_devp->rx_buf); + r = copy_to_user(buf, smd_pkt_devp->rx_buf, bytes_read); + mutex_unlock(&smd_pkt_devp->rx_lock); + if (r) { + pr_err("copy_to_user failed %d\n", r); + return -EFAULT; + } + + DBG("read complete %d bytes\n", bytes_read); + check_and_wakeup_reader(smd_pkt_devp); + + return bytes_read; +} + +static int smd_pkt_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + int r; + struct smd_pkt_dev *smd_pkt_devp; + + if (count > MAX_BUF_SIZE) + return -EINVAL; + + DBG("writting %d bytes\n", count); + + smd_pkt_devp = file->private_data; + if (!smd_pkt_devp || !smd_pkt_devp->ch) + return -EINVAL; + + mutex_lock(&smd_pkt_devp->tx_lock); + if (smd_write_avail(smd_pkt_devp->ch) < count) { + mutex_unlock(&smd_pkt_devp->tx_lock); + DBG("Not enough space to write\n"); + return -ENOMEM; + } + + D_DUMP_BUFFER("write: ", count, buf); + r = copy_from_user(smd_pkt_devp->tx_buf, buf, count); + if (r) { + mutex_unlock(&smd_pkt_devp->tx_lock); + pr_err("copy_from_user failed %d\n", r); + return -EFAULT; + } + + r = smd_write(smd_pkt_devp->ch, smd_pkt_devp->tx_buf, count); + if (r != count) { + mutex_unlock(&smd_pkt_devp->tx_lock); + pr_err("smd_write failed to write %d bytes: %d.\n", count, r); + return -EIO; + } + mutex_unlock(&smd_pkt_devp->tx_lock); + + DBG("wrote %d bytes\n", count); + return count; +} + +static unsigned int smd_pkt_poll(struct file *file, poll_table *wait) +{ + struct smd_pkt_dev *smd_pkt_devp; + unsigned int mask = 0; + + smd_pkt_devp = file->private_data; + if (!smd_pkt_devp) + return POLLERR; + + DBG("poll waiting\n"); + poll_wait(file, &smd_pkt_devp->ch_read_wait_queue, wait); + if (smd_read_avail(smd_pkt_devp->ch)) + mask |= POLLIN | POLLRDNORM; + + DBG("poll return\n"); + return mask; +} + +static void smd_pkt_ch_notify(void *priv, unsigned event) +{ + struct smd_pkt_dev *smd_pkt_devp = priv; + + if (smd_pkt_devp->ch == 0) + return; + + switch (event) { + case SMD_EVENT_DATA: + DBG("data\n"); + check_and_wakeup_reader(smd_pkt_devp); + break; + + case SMD_EVENT_OPEN: + DBG("remote open\n"); + smd_pkt_devp->remote_open = 1; + wake_up_interruptible(&smd_pkt_devp->ch_opened_wait_queue); + break; + + case SMD_EVENT_CLOSE: + smd_pkt_devp->remote_open = 0; + pr_info("remote closed\n"); + break; + + default: + pr_err("unknown event %d\n", event); + break; + } +} + +static char *smd_pkt_dev_name[] = { + "smdcntl0", + "smdcntl1", + "smdcntl2", + "smdcntl3", + "smdcntl4", + "smdcntl5", + "smdcntl6", + "smdcntl7", + "smd22", +}; + +static char *smd_ch_name[] = { + "DATA5_CNTL", + "DATA6_CNTL", + "DATA7_CNTL", + "DATA8_CNTL", + "DATA9_CNTL", + "DATA12_CNTL", + "DATA13_CNTL", + "DATA14_CNTL", + "DATA22", +}; + +static int smd_pkt_open(struct inode *inode, struct file *file) +{ + int r = 0; + struct smd_pkt_dev *smd_pkt_devp; + + smd_pkt_devp = container_of(inode->i_cdev, struct smd_pkt_dev, cdev); + if (!smd_pkt_devp) + return -EINVAL; + + file->private_data = smd_pkt_devp; + + mutex_lock(&smd_pkt_devp->ch_lock); + if (smd_pkt_devp->open_count == 0) { + r = smd_open(smd_ch_name[smd_pkt_devp->i], + &smd_pkt_devp->ch, smd_pkt_devp, + smd_pkt_ch_notify); + if (r < 0) { + pr_err("smd_open failed for %s, %d\n", + smd_ch_name[smd_pkt_devp->i], r); + goto out; + } + + r = wait_event_interruptible_timeout( + smd_pkt_devp->ch_opened_wait_queue, + smd_pkt_devp->remote_open, + msecs_to_jiffies(2 * HZ)); + if (r == 0) + r = -ETIMEDOUT; + + if (r < 0) { + pr_err("wait returned %d\n", r); + smd_close(smd_pkt_devp->ch); + smd_pkt_devp->ch = 0; + } else { + smd_pkt_devp->open_count++; + r = 0; + } + } +out: + mutex_unlock(&smd_pkt_devp->ch_lock); + return r; +} + +static int smd_pkt_release(struct inode *inode, struct file *file) +{ + int r = 0; + struct smd_pkt_dev *smd_pkt_devp = file->private_data; + + if (!smd_pkt_devp) + return -EINVAL; + + mutex_lock(&smd_pkt_devp->ch_lock); + if (--smd_pkt_devp->open_count == 0) { + r = smd_close(smd_pkt_devp->ch); + smd_pkt_devp->ch = 0; + } + mutex_unlock(&smd_pkt_devp->ch_lock); + + return r; +} + +static const struct file_operations smd_pkt_fops = { + .owner = THIS_MODULE, + .open = smd_pkt_open, + .release = smd_pkt_release, + .read = smd_pkt_read, + .write = smd_pkt_write, + .poll = smd_pkt_poll, +}; + +static int __init smd_pkt_init(void) +{ + int i; + int r; + + r = alloc_chrdev_region(&smd_pkt_number, 0, + NUM_SMD_PKT_PORTS, DEVICE_NAME); + if (r) { + pr_err("alloc_chrdev_region() failed %d\n", r); + return r; + } + + smd_pkt_classp = class_create(THIS_MODULE, DEVICE_NAME); + if (IS_ERR(smd_pkt_classp)) { + r = PTR_ERR(smd_pkt_classp); + pr_err("class_create() failed %d\n", r); + goto unreg_chardev; + } + + for (i = 0; i < NUM_SMD_PKT_PORTS; ++i) { + smd_pkt_devp[i] = kzalloc(sizeof(struct smd_pkt_dev), + GFP_KERNEL); + if (IS_ERR(smd_pkt_devp[i])) { + r = PTR_ERR(smd_pkt_devp[i]); + pr_err("kmalloc() failed %d\n", r); + goto clean_cdevs; + } + + smd_pkt_devp[i]->i = i; + + init_waitqueue_head(&smd_pkt_devp[i]->ch_read_wait_queue); + smd_pkt_devp[i]->remote_open = 0; + init_waitqueue_head(&smd_pkt_devp[i]->ch_opened_wait_queue); + + mutex_init(&smd_pkt_devp[i]->ch_lock); + mutex_init(&smd_pkt_devp[i]->rx_lock); + mutex_init(&smd_pkt_devp[i]->tx_lock); + + cdev_init(&smd_pkt_devp[i]->cdev, &smd_pkt_fops); + smd_pkt_devp[i]->cdev.owner = THIS_MODULE; + + r = cdev_add(&smd_pkt_devp[i]->cdev, + (smd_pkt_number + i), 1); + if (r) { + pr_err("cdev_add() failed %d\n", r); + kfree(smd_pkt_devp[i]); + goto clean_cdevs; + } + + smd_pkt_devp[i]->devicep = + device_create(smd_pkt_classp, NULL, + (smd_pkt_number + i), NULL, + smd_pkt_dev_name[i]); + if (IS_ERR(smd_pkt_devp[i]->devicep)) { + r = PTR_ERR(smd_pkt_devp[i]->devicep); + pr_err("device_create() failed %d\n", r); + cdev_del(&smd_pkt_devp[i]->cdev); + kfree(smd_pkt_devp[i]); + goto clean_cdevs; + } + + } + + pr_info("SMD Packet Port Driver Initialized.\n"); + return 0; + +clean_cdevs: + if (i > 0) { + while (--i >= 0) { + mutex_destroy(&smd_pkt_devp[i]->ch_lock); + mutex_destroy(&smd_pkt_devp[i]->rx_lock); + mutex_destroy(&smd_pkt_devp[i]->tx_lock); + cdev_del(&smd_pkt_devp[i]->cdev); + kfree(smd_pkt_devp[i]); + device_destroy(smd_pkt_classp, + MKDEV(MAJOR(smd_pkt_number), i)); + } + } + + class_destroy(smd_pkt_classp); +unreg_chardev: + unregister_chrdev_region(MAJOR(smd_pkt_number), NUM_SMD_PKT_PORTS); + return r; +} +module_init(smd_pkt_init); + +static void __exit smd_pkt_cleanup(void) +{ + int i; + + for (i = 0; i < NUM_SMD_PKT_PORTS; ++i) { + mutex_destroy(&smd_pkt_devp[i]->ch_lock); + mutex_destroy(&smd_pkt_devp[i]->rx_lock); + mutex_destroy(&smd_pkt_devp[i]->tx_lock); + cdev_del(&smd_pkt_devp[i]->cdev); + kfree(smd_pkt_devp[i]); + device_destroy(smd_pkt_classp, + MKDEV(MAJOR(smd_pkt_number), i)); + } + + class_destroy(smd_pkt_classp); + unregister_chrdev_region(MAJOR(smd_pkt_number), NUM_SMD_PKT_PORTS); +} +module_exit(smd_pkt_cleanup); + +MODULE_DESCRIPTION("MSM Shared Memory Packet Port"); +MODULE_LICENSE("GPL v2"); |