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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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467 lines
11 KiB
C
467 lines
11 KiB
C
![]() |
/* Copyright (c) 2008-2010, Code Aurora Forum. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 and
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* only version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*
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*/
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/*
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* SMD Packet Driver -- Provides userspace interface to SMD packet ports.
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*/
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#include <linux/slab.h>
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#include <linux/cdev.h>
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <linux/device.h>
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#include <linux/sched.h>
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#include <linux/mutex.h>
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#include <linux/delay.h>
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#include <linux/uaccess.h>
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#include <linux/workqueue.h>
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#include <linux/poll.h>
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#include <mach/msm_smd.h>
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#define NUM_SMD_PKT_PORTS 9
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#define DEVICE_NAME "smdpkt"
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#define MAX_BUF_SIZE 2048
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struct smd_pkt_dev {
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struct cdev cdev;
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struct device *devicep;
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struct smd_channel *ch;
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int open_count;
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struct mutex ch_lock;
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struct mutex rx_lock;
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struct mutex tx_lock;
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wait_queue_head_t ch_read_wait_queue;
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wait_queue_head_t ch_opened_wait_queue;
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int i;
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unsigned char tx_buf[MAX_BUF_SIZE];
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unsigned char rx_buf[MAX_BUF_SIZE];
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int remote_open;
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} *smd_pkt_devp[NUM_SMD_PKT_PORTS];
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struct class *smd_pkt_classp;
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static dev_t smd_pkt_number;
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static int msm_smd_pkt_debug_enable;
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module_param_named(debug_enable, msm_smd_pkt_debug_enable,
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int, S_IRUGO | S_IWUSR | S_IWGRP);
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#ifdef DEBUG
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#define D_DUMP_BUFFER(prestr, cnt, buf) do { \
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int i; \
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if (msm_smd_pkt_debug_enable) { \
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pr_debug("%s", prestr); \
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for (i = 0; i < cnt; i++) \
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pr_debug("%.2x", buf[i]); \
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pr_debug("\n"); \
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} \
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} while (0)
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#else
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#define D_DUMP_BUFFER(prestr, cnt, buf) do {} while (0)
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#endif
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#ifdef DEBUG
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#define DBG(x...) do { \
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if (msm_smd_pkt_debug_enable) \
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pr_debug(x); \
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} while (0)
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#else
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#define DBG(x...) do {} while (0)
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#endif
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static void check_and_wakeup_reader(struct smd_pkt_dev *smd_pkt_devp)
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{
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int sz;
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if (!smd_pkt_devp || !smd_pkt_devp->ch)
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return;
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sz = smd_cur_packet_size(smd_pkt_devp->ch);
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if (sz == 0) {
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DBG("no packet\n");
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return;
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}
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if (sz > smd_read_avail(smd_pkt_devp->ch)) {
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DBG("incomplete packet\n");
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return;
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}
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DBG("waking up reader\n");
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wake_up_interruptible(&smd_pkt_devp->ch_read_wait_queue);
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}
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static int smd_pkt_read(struct file *file, char __user *buf,
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size_t count, loff_t *ppos)
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{
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int r, bytes_read;
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struct smd_pkt_dev *smd_pkt_devp;
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struct smd_channel *chl;
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DBG("read %d bytes\n", count);
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if (count > MAX_BUF_SIZE)
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return -EINVAL;
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smd_pkt_devp = file->private_data;
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if (!smd_pkt_devp || !smd_pkt_devp->ch)
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return -EINVAL;
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chl = smd_pkt_devp->ch;
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wait_for_packet:
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r = wait_event_interruptible(smd_pkt_devp->ch_read_wait_queue,
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(smd_cur_packet_size(chl) > 0 &&
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smd_read_avail(chl) >=
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smd_cur_packet_size(chl)));
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if (r < 0) {
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if (r != -ERESTARTSYS)
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pr_err("wait returned %d\n", r);
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return r;
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}
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mutex_lock(&smd_pkt_devp->rx_lock);
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bytes_read = smd_cur_packet_size(smd_pkt_devp->ch);
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if (bytes_read == 0 ||
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bytes_read < smd_read_avail(smd_pkt_devp->ch)) {
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mutex_unlock(&smd_pkt_devp->rx_lock);
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DBG("Nothing to read\n");
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goto wait_for_packet;
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}
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if (bytes_read > count) {
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mutex_unlock(&smd_pkt_devp->rx_lock);
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pr_info("packet size %d > buffer size %d", bytes_read, count);
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return -EINVAL;
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}
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r = smd_read(smd_pkt_devp->ch, smd_pkt_devp->rx_buf, bytes_read);
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if (r != bytes_read) {
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mutex_unlock(&smd_pkt_devp->rx_lock);
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pr_err("smd_read failed to read %d bytes: %d\n", bytes_read, r);
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return -EIO;
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}
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D_DUMP_BUFFER("read: ", bytes_read, smd_pkt_devp->rx_buf);
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r = copy_to_user(buf, smd_pkt_devp->rx_buf, bytes_read);
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mutex_unlock(&smd_pkt_devp->rx_lock);
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if (r) {
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pr_err("copy_to_user failed %d\n", r);
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return -EFAULT;
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}
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DBG("read complete %d bytes\n", bytes_read);
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check_and_wakeup_reader(smd_pkt_devp);
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return bytes_read;
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}
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static int smd_pkt_write(struct file *file, const char __user *buf,
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size_t count, loff_t *ppos)
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{
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int r;
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struct smd_pkt_dev *smd_pkt_devp;
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if (count > MAX_BUF_SIZE)
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return -EINVAL;
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DBG("writting %d bytes\n", count);
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smd_pkt_devp = file->private_data;
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if (!smd_pkt_devp || !smd_pkt_devp->ch)
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return -EINVAL;
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mutex_lock(&smd_pkt_devp->tx_lock);
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if (smd_write_avail(smd_pkt_devp->ch) < count) {
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mutex_unlock(&smd_pkt_devp->tx_lock);
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DBG("Not enough space to write\n");
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return -ENOMEM;
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}
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D_DUMP_BUFFER("write: ", count, buf);
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r = copy_from_user(smd_pkt_devp->tx_buf, buf, count);
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if (r) {
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mutex_unlock(&smd_pkt_devp->tx_lock);
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pr_err("copy_from_user failed %d\n", r);
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return -EFAULT;
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}
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r = smd_write(smd_pkt_devp->ch, smd_pkt_devp->tx_buf, count);
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if (r != count) {
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mutex_unlock(&smd_pkt_devp->tx_lock);
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pr_err("smd_write failed to write %d bytes: %d.\n", count, r);
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return -EIO;
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}
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mutex_unlock(&smd_pkt_devp->tx_lock);
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DBG("wrote %d bytes\n", count);
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return count;
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}
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static unsigned int smd_pkt_poll(struct file *file, poll_table *wait)
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{
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struct smd_pkt_dev *smd_pkt_devp;
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unsigned int mask = 0;
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smd_pkt_devp = file->private_data;
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if (!smd_pkt_devp)
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return POLLERR;
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DBG("poll waiting\n");
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poll_wait(file, &smd_pkt_devp->ch_read_wait_queue, wait);
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if (smd_read_avail(smd_pkt_devp->ch))
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mask |= POLLIN | POLLRDNORM;
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DBG("poll return\n");
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return mask;
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}
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static void smd_pkt_ch_notify(void *priv, unsigned event)
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{
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struct smd_pkt_dev *smd_pkt_devp = priv;
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if (smd_pkt_devp->ch == 0)
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return;
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switch (event) {
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case SMD_EVENT_DATA:
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DBG("data\n");
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check_and_wakeup_reader(smd_pkt_devp);
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break;
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case SMD_EVENT_OPEN:
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DBG("remote open\n");
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smd_pkt_devp->remote_open = 1;
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wake_up_interruptible(&smd_pkt_devp->ch_opened_wait_queue);
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break;
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case SMD_EVENT_CLOSE:
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smd_pkt_devp->remote_open = 0;
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pr_info("remote closed\n");
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break;
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default:
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pr_err("unknown event %d\n", event);
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break;
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}
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}
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static char *smd_pkt_dev_name[] = {
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"smdcntl0",
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"smdcntl1",
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"smdcntl2",
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"smdcntl3",
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"smdcntl4",
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"smdcntl5",
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"smdcntl6",
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"smdcntl7",
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"smd22",
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};
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static char *smd_ch_name[] = {
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"DATA5_CNTL",
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"DATA6_CNTL",
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"DATA7_CNTL",
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"DATA8_CNTL",
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"DATA9_CNTL",
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"DATA12_CNTL",
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"DATA13_CNTL",
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"DATA14_CNTL",
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"DATA22",
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};
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static int smd_pkt_open(struct inode *inode, struct file *file)
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{
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int r = 0;
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struct smd_pkt_dev *smd_pkt_devp;
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smd_pkt_devp = container_of(inode->i_cdev, struct smd_pkt_dev, cdev);
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if (!smd_pkt_devp)
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return -EINVAL;
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file->private_data = smd_pkt_devp;
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mutex_lock(&smd_pkt_devp->ch_lock);
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if (smd_pkt_devp->open_count == 0) {
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r = smd_open(smd_ch_name[smd_pkt_devp->i],
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&smd_pkt_devp->ch, smd_pkt_devp,
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smd_pkt_ch_notify);
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if (r < 0) {
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pr_err("smd_open failed for %s, %d\n",
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smd_ch_name[smd_pkt_devp->i], r);
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goto out;
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}
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r = wait_event_interruptible_timeout(
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smd_pkt_devp->ch_opened_wait_queue,
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smd_pkt_devp->remote_open,
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msecs_to_jiffies(2 * HZ));
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if (r == 0)
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r = -ETIMEDOUT;
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if (r < 0) {
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pr_err("wait returned %d\n", r);
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smd_close(smd_pkt_devp->ch);
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smd_pkt_devp->ch = 0;
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} else {
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smd_pkt_devp->open_count++;
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r = 0;
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}
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}
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out:
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mutex_unlock(&smd_pkt_devp->ch_lock);
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return r;
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}
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static int smd_pkt_release(struct inode *inode, struct file *file)
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{
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int r = 0;
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struct smd_pkt_dev *smd_pkt_devp = file->private_data;
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if (!smd_pkt_devp)
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return -EINVAL;
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mutex_lock(&smd_pkt_devp->ch_lock);
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if (--smd_pkt_devp->open_count == 0) {
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r = smd_close(smd_pkt_devp->ch);
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smd_pkt_devp->ch = 0;
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}
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mutex_unlock(&smd_pkt_devp->ch_lock);
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return r;
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}
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static const struct file_operations smd_pkt_fops = {
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.owner = THIS_MODULE,
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.open = smd_pkt_open,
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.release = smd_pkt_release,
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.read = smd_pkt_read,
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.write = smd_pkt_write,
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.poll = smd_pkt_poll,
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};
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static int __init smd_pkt_init(void)
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{
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int i;
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int r;
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r = alloc_chrdev_region(&smd_pkt_number, 0,
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NUM_SMD_PKT_PORTS, DEVICE_NAME);
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if (r) {
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pr_err("alloc_chrdev_region() failed %d\n", r);
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return r;
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}
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smd_pkt_classp = class_create(THIS_MODULE, DEVICE_NAME);
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if (IS_ERR(smd_pkt_classp)) {
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r = PTR_ERR(smd_pkt_classp);
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pr_err("class_create() failed %d\n", r);
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goto unreg_chardev;
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}
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for (i = 0; i < NUM_SMD_PKT_PORTS; ++i) {
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smd_pkt_devp[i] = kzalloc(sizeof(struct smd_pkt_dev),
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GFP_KERNEL);
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if (IS_ERR(smd_pkt_devp[i])) {
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r = PTR_ERR(smd_pkt_devp[i]);
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pr_err("kmalloc() failed %d\n", r);
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goto clean_cdevs;
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}
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smd_pkt_devp[i]->i = i;
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init_waitqueue_head(&smd_pkt_devp[i]->ch_read_wait_queue);
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smd_pkt_devp[i]->remote_open = 0;
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init_waitqueue_head(&smd_pkt_devp[i]->ch_opened_wait_queue);
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mutex_init(&smd_pkt_devp[i]->ch_lock);
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mutex_init(&smd_pkt_devp[i]->rx_lock);
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mutex_init(&smd_pkt_devp[i]->tx_lock);
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cdev_init(&smd_pkt_devp[i]->cdev, &smd_pkt_fops);
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smd_pkt_devp[i]->cdev.owner = THIS_MODULE;
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r = cdev_add(&smd_pkt_devp[i]->cdev,
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(smd_pkt_number + i), 1);
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if (r) {
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pr_err("cdev_add() failed %d\n", r);
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kfree(smd_pkt_devp[i]);
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goto clean_cdevs;
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}
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smd_pkt_devp[i]->devicep =
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device_create(smd_pkt_classp, NULL,
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(smd_pkt_number + i), NULL,
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smd_pkt_dev_name[i]);
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||
|
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");
|