cregit-Linux how code gets into the kernel

Release 4.11 drivers/input/serio/serio_raw.c

/*
 * Raw serio device providing access to a raw byte stream from underlying
 * serio port. Closely emulates behavior of pre-2.6 /dev/psaux device
 *
 * Copyright (c) 2004 Dmitry Torokhov
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */

#include <linux/kref.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/module.h>
#include <linux/serio.h>
#include <linux/major.h>
#include <linux/device.h>
#include <linux/miscdevice.h>
#include <linux/wait.h>
#include <linux/mutex.h>


#define DRIVER_DESC	"Raw serio driver"

MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");


#define SERIO_RAW_QUEUE_LEN	64

struct serio_raw {
	
unsigned char queue[SERIO_RAW_QUEUE_LEN];
	

unsigned int tail, head;

	
char name[16];
	
struct kref kref;
	
struct serio *serio;
	
struct miscdevice dev;
	
wait_queue_head_t wait;
	
struct list_head client_list;
	
struct list_head node;
	
bool dead;
};


struct serio_raw_client {
	
struct fasync_struct *fasync;
	
struct serio_raw *serio_raw;
	
struct list_head node;
};

static DEFINE_MUTEX(serio_raw_mutex);
static LIST_HEAD(serio_raw_list);

/*********************************************************************
 *             Interface with userspace (file operations)            *
 *********************************************************************/


static int serio_raw_fasync(int fd, struct file *file, int on) { struct serio_raw_client *client = file->private_data; return fasync_helper(fd, file, on, &client->fasync); }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov4097.56%266.67%
Jonathan Corbet12.44%133.33%
Total41100.00%3100.00%


static struct serio_raw *serio_raw_locate(int minor) { struct serio_raw *serio_raw; list_for_each_entry(serio_raw, &serio_raw_list, node) { if (serio_raw->dev.minor == minor) return serio_raw; } return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov42100.00%1100.00%
Total42100.00%1100.00%


static int serio_raw_open(struct inode *inode, struct file *file) { struct serio_raw *serio_raw; struct serio_raw_client *client; int retval; retval = mutex_lock_interruptible(&serio_raw_mutex); if (retval) return retval; serio_raw = serio_raw_locate(iminor(inode)); if (!serio_raw) { retval = -ENODEV; goto out; } if (serio_raw->dead) { retval = -ENODEV; goto out; } client = kzalloc(sizeof(struct serio_raw_client), GFP_KERNEL); if (!client) { retval = -ENOMEM; goto out; } client->serio_raw = serio_raw; file->private_data = client; kref_get(&serio_raw->kref); serio_pause_rx(serio_raw->serio); list_add_tail(&client->node, &serio_raw->client_list); serio_continue_rx(serio_raw->serio); out: mutex_unlock(&serio_raw_mutex); return retval; }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov15490.06%562.50%
Thadeu Lima de Souza Cascardo127.02%112.50%
Arjan van de Ven42.34%112.50%
Eric Sesterhenn / Snakebyte10.58%112.50%
Total171100.00%8100.00%


static void serio_raw_free(struct kref *kref) { struct serio_raw *serio_raw = container_of(kref, struct serio_raw, kref); put_device(&serio_raw->serio->dev); kfree(serio_raw); }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov41100.00%4100.00%
Total41100.00%4100.00%


static int serio_raw_release(struct inode *inode, struct file *file) { struct serio_raw_client *client = file->private_data; struct serio_raw *serio_raw = client->serio_raw; serio_pause_rx(serio_raw->serio); list_del(&client->node); serio_continue_rx(serio_raw->serio); kfree(client); kref_put(&serio_raw->kref, serio_raw_free); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov74100.00%4100.00%
Total74100.00%4100.00%


static bool serio_raw_fetch_byte(struct serio_raw *serio_raw, char *c) { bool empty; serio_pause_rx(serio_raw->serio); empty = serio_raw->head == serio_raw->tail; if (!empty) { *c = serio_raw->queue[serio_raw->tail]; serio_raw->tail = (serio_raw->tail + 1) % SERIO_RAW_QUEUE_LEN; } serio_continue_rx(serio_raw->serio); return !empty; }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov79100.00%3100.00%
Total79100.00%3100.00%


static ssize_t serio_raw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) { struct serio_raw_client *client = file->private_data; struct serio_raw *serio_raw = client->serio_raw; char uninitialized_var(c); ssize_t read = 0; int error; for (;;) { if (serio_raw->dead) return -ENODEV; if (serio_raw->head == serio_raw->tail && (file->f_flags & O_NONBLOCK)) return -EAGAIN; if (count == 0) break; while (read < count && serio_raw_fetch_byte(serio_raw, &c)) { if (put_user(c, buffer++)) return -EFAULT; read++; } if (read) break; if (!(file->f_flags & O_NONBLOCK)) { error = wait_event_interruptible(serio_raw->wait, serio_raw->head != serio_raw->tail || serio_raw->dead); if (error) return error; } } return read; }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov17495.08%562.50%
Che-Liang Chiou52.73%112.50%
Andrew Morton31.64%112.50%
Al Viro10.55%112.50%
Total183100.00%8100.00%


static ssize_t serio_raw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos) { struct serio_raw_client *client = file->private_data; struct serio_raw *serio_raw = client->serio_raw; int retval = 0; unsigned char c; retval = mutex_lock_interruptible(&serio_raw_mutex); if (retval) return retval; if (serio_raw->dead) { retval = -ENODEV; goto out; } if (count > 32) count = 32; while (count--) { if (get_user(c, buffer++)) { retval = -EFAULT; goto out; } if (serio_write(serio_raw->serio, c)) { /* Either signal error or partial write */ if (retval == 0) retval = -EIO; goto out; } retval++; } out: mutex_unlock(&serio_raw_mutex); return retval; }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov15696.89%571.43%
Arjan van de Ven42.48%114.29%
Al Viro10.62%114.29%
Total161100.00%7100.00%


static unsigned int serio_raw_poll(struct file *file, poll_table *wait) { struct serio_raw_client *client = file->private_data; struct serio_raw *serio_raw = client->serio_raw; unsigned int mask; poll_wait(file, &serio_raw->wait, wait); mask = serio_raw->dead ? POLLHUP | POLLERR : POLLOUT | POLLWRNORM; if (serio_raw->head != serio_raw->tail) mask |= POLLIN | POLLRDNORM; return mask; }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov83100.00%4100.00%
Total83100.00%4100.00%

static const struct file_operations serio_raw_fops = { .owner = THIS_MODULE, .open = serio_raw_open, .release = serio_raw_release, .read = serio_raw_read, .write = serio_raw_write, .poll = serio_raw_poll, .fasync = serio_raw_fasync, .llseek = noop_llseek, }; /********************************************************************* * Interface with serio port * *********************************************************************/
static irqreturn_t serio_raw_interrupt(struct serio *serio, unsigned char data, unsigned int dfl) { struct serio_raw *serio_raw = serio_get_drvdata(serio); struct serio_raw_client *client; unsigned int head = serio_raw->head; /* we are holding serio->lock here so we are protected */ serio_raw->queue[head] = data; head = (head + 1) % SERIO_RAW_QUEUE_LEN; if (likely(head != serio_raw->tail)) { serio_raw->head = head; list_for_each_entry(client, &serio_raw->client_list, node) kill_fasync(&client->fasync, SIGIO, POLL_IN); wake_up_interruptible(&serio_raw->wait); } return IRQ_HANDLED; }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov112100.00%3100.00%
Total112100.00%3100.00%


static int serio_raw_connect(struct serio *serio, struct serio_driver *drv) { static atomic_t serio_raw_no = ATOMIC_INIT(-1); struct serio_raw *serio_raw; int err; serio_raw = kzalloc(sizeof(struct serio_raw), GFP_KERNEL); if (!serio_raw) { dev_dbg(&serio->dev, "can't allocate memory for a device\n"); return -ENOMEM; } snprintf(serio_raw->name, sizeof(serio_raw->name), "serio_raw%ld", (long)atomic_inc_return(&serio_raw_no)); kref_init(&serio_raw->kref); INIT_LIST_HEAD(&serio_raw->client_list); init_waitqueue_head(&serio_raw->wait); serio_raw->serio = serio; get_device(&serio->dev); serio_set_drvdata(serio, serio_raw); err = serio_open(serio, drv); if (err) goto err_free; err = mutex_lock_killable(&serio_raw_mutex); if (err) goto err_close; list_add_tail(&serio_raw->node, &serio_raw_list); mutex_unlock(&serio_raw_mutex); serio_raw->dev.minor = PSMOUSE_MINOR; serio_raw->dev.name = serio_raw->name; serio_raw->dev.parent = &serio->dev; serio_raw->dev.fops = &serio_raw_fops; err = misc_register(&serio_raw->dev); if (err) { serio_raw->dev.minor = MISC_DYNAMIC_MINOR; err = misc_register(&serio_raw->dev); } if (err) { dev_err(&serio->dev, "failed to register raw access device for %s\n", serio->phys); goto err_unlink; } dev_info(&serio->dev, "raw access enabled on %s (%s, minor %d)\n", serio->phys, serio_raw->name, serio_raw->dev.minor); return 0; err_unlink: list_del_init(&serio_raw->node); err_close: serio_close(serio); err_free: serio_set_drvdata(serio, NULL); kref_put(&serio_raw->kref, serio_raw_free); return err; }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov34398.85%1076.92%
Aniroop Mathur20.58%17.69%
Greg Kroah-Hartman10.29%17.69%
Eric Sesterhenn / Snakebyte10.29%17.69%
Total347100.00%13100.00%


static int serio_raw_reconnect(struct serio *serio) { struct serio_raw *serio_raw = serio_get_drvdata(serio); struct serio_driver *drv = serio->drv; if (!drv || !serio_raw) { dev_dbg(&serio->dev, "reconnect request, but serio is disconnected, ignoring...\n"); return -1; } /* * Nothing needs to be done here, we just need this method to * keep the same device. */ return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov58100.00%3100.00%
Total58100.00%3100.00%

/* * Wake up users waiting for IO so they can disconnect from * dead device. */
static void serio_raw_hangup(struct serio_raw *serio_raw) { struct serio_raw_client *client; serio_pause_rx(serio_raw->serio); list_for_each_entry(client, &serio_raw->client_list, node) kill_fasync(&client->fasync, SIGIO, POLL_HUP); serio_continue_rx(serio_raw->serio); wake_up_interruptible(&serio_raw->wait); }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov58100.00%1100.00%
Total58100.00%1100.00%


static void serio_raw_disconnect(struct serio *serio) { struct serio_raw *serio_raw = serio_get_drvdata(serio); misc_deregister(&serio_raw->dev); mutex_lock(&serio_raw_mutex); serio_raw->dead = true; list_del_init(&serio_raw->node); mutex_unlock(&serio_raw_mutex); serio_raw_hangup(serio_raw); serio_close(serio); kref_put(&serio_raw->kref, serio_raw_free); serio_set_drvdata(serio, NULL); }

Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov82100.00%5100.00%
Total82100.00%5100.00%

static struct serio_device_id serio_raw_serio_ids[] = { { .type = SERIO_8042, .proto = SERIO_ANY, .id = SERIO_ANY, .extra = SERIO_ANY, }, { .type = SERIO_8042_XL, .proto = SERIO_ANY, .id = SERIO_ANY, .extra = SERIO_ANY, }, { 0 } }; MODULE_DEVICE_TABLE(serio, serio_raw_serio_ids); static struct serio_driver serio_raw_drv = { .driver = { .name = "serio_raw", }, .description = DRIVER_DESC, .id_table = serio_raw_serio_ids, .interrupt = serio_raw_interrupt, .connect = serio_raw_connect, .reconnect = serio_raw_reconnect, .disconnect = serio_raw_disconnect, .manual_bind = true, }; module_serio_driver(serio_raw_drv);

Overall Contributors

PersonTokensPropCommitsCommitProp
Dmitry Torokhov176795.93%1854.55%
Niels de Vos221.19%13.03%
Arjan van de Ven140.76%26.06%
Thadeu Lima de Souza Cascardo120.65%13.03%
Che-Liang Chiou50.27%13.03%
Arnd Bergmann50.27%13.03%
Alexey Dobriyan30.16%13.03%
Andrew Morton30.16%13.03%
Eric Sesterhenn / Snakebyte20.11%13.03%
Al Viro20.11%13.03%
Axel Lin20.11%13.03%
Aniroop Mathur20.11%13.03%
Adrian Bunk10.05%13.03%
Greg Kroah-Hartman10.05%13.03%
Jonathan Corbet10.05%13.03%
Total1842100.00%33100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.