| /* 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"); |