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-rw-r--r--kernel/drivers/input/serio/Kconfig15
-rw-r--r--kernel/drivers/input/serio/Makefile1
-rw-r--r--kernel/drivers/input/serio/ambakmi.c8
-rw-r--r--kernel/drivers/input/serio/i8042-x86ia64io.h7
-rw-r--r--kernel/drivers/input/serio/i8042.c77
-rw-r--r--kernel/drivers/input/serio/i8042.h13
-rw-r--r--kernel/drivers/input/serio/libps2.c22
-rw-r--r--kernel/drivers/input/serio/parkbd.c59
-rw-r--r--kernel/drivers/input/serio/serio.c5
-rw-r--r--kernel/drivers/input/serio/serport.c5
-rw-r--r--kernel/drivers/input/serio/userio.c285
11 files changed, 451 insertions, 46 deletions
diff --git a/kernel/drivers/input/serio/Kconfig b/kernel/drivers/input/serio/Kconfig
index 77833d7a0..c3d05b4d3 100644
--- a/kernel/drivers/input/serio/Kconfig
+++ b/kernel/drivers/input/serio/Kconfig
@@ -244,6 +244,7 @@ config SERIO_PS2MULT
config SERIO_ARC_PS2
tristate "ARC PS/2 support"
+ depends on HAS_IOMEM
help
Say Y here if you have an ARC FPGA platform with a PS/2
controller in it.
@@ -291,4 +292,18 @@ config SERIO_SUN4I_PS2
To compile this driver as a module, choose M here: the
module will be called sun4i-ps2.
+config USERIO
+ tristate "User space serio port driver support"
+ help
+ Say Y here if you want to support user level drivers for serio
+ subsystem accessible under char device 10:240 - /dev/userio. Using
+ this facility userspace programs can implement serio ports that
+ will be used by the standard in-kernel serio consumer drivers,
+ such as psmouse and atkbd.
+
+ To compile this driver as a module, choose M here: the module will be
+ called userio.
+
+ If you are unsure, say N.
+
endif
diff --git a/kernel/drivers/input/serio/Makefile b/kernel/drivers/input/serio/Makefile
index c600089b7..2374ef9b3 100644
--- a/kernel/drivers/input/serio/Makefile
+++ b/kernel/drivers/input/serio/Makefile
@@ -30,3 +30,4 @@ obj-$(CONFIG_SERIO_APBPS2) += apbps2.o
obj-$(CONFIG_SERIO_OLPC_APSP) += olpc_apsp.o
obj-$(CONFIG_HYPERV_KEYBOARD) += hyperv-keyboard.o
obj-$(CONFIG_SERIO_SUN4I_PS2) += sun4i-ps2.o
+obj-$(CONFIG_USERIO) += userio.o
diff --git a/kernel/drivers/input/serio/ambakmi.c b/kernel/drivers/input/serio/ambakmi.c
index 8b748d99b..c6606cacb 100644
--- a/kernel/drivers/input/serio/ambakmi.c
+++ b/kernel/drivers/input/serio/ambakmi.c
@@ -175,9 +175,9 @@ static int amba_kmi_remove(struct amba_device *dev)
return 0;
}
-static int amba_kmi_resume(struct amba_device *dev)
+static int __maybe_unused amba_kmi_resume(struct device *dev)
{
- struct amba_kmi_port *kmi = amba_get_drvdata(dev);
+ struct amba_kmi_port *kmi = dev_get_drvdata(dev);
/* kick the serio layer to rescan this port */
serio_reconnect(kmi->io);
@@ -185,6 +185,8 @@ static int amba_kmi_resume(struct amba_device *dev)
return 0;
}
+static SIMPLE_DEV_PM_OPS(amba_kmi_dev_pm_ops, NULL, amba_kmi_resume);
+
static struct amba_id amba_kmi_idtable[] = {
{
.id = 0x00041050,
@@ -199,11 +201,11 @@ static struct amba_driver ambakmi_driver = {
.drv = {
.name = "kmi-pl050",
.owner = THIS_MODULE,
+ .pm = &amba_kmi_dev_pm_ops,
},
.id_table = amba_kmi_idtable,
.probe = amba_kmi_probe,
.remove = amba_kmi_remove,
- .resume = amba_kmi_resume,
};
module_amba_driver(ambakmi_driver);
diff --git a/kernel/drivers/input/serio/i8042-x86ia64io.h b/kernel/drivers/input/serio/i8042-x86ia64io.h
index c11556563..68f5f4a0f 100644
--- a/kernel/drivers/input/serio/i8042-x86ia64io.h
+++ b/kernel/drivers/input/serio/i8042-x86ia64io.h
@@ -258,6 +258,13 @@ static const struct dmi_system_id __initconst i8042_dmi_nomux_table[] = {
},
},
{
+ /* Fujitsu Lifebook U745 */
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK U745"),
+ },
+ },
+ {
/* Fujitsu T70H */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU"),
diff --git a/kernel/drivers/input/serio/i8042.c b/kernel/drivers/input/serio/i8042.c
index cb5ece77f..454195709 100644
--- a/kernel/drivers/input/serio/i8042.c
+++ b/kernel/drivers/input/serio/i8042.c
@@ -24,6 +24,7 @@
#include <linux/platform_device.h>
#include <linux/i8042.h>
#include <linux/slab.h>
+#include <linux/suspend.h>
#include <asm/io.h>
@@ -88,6 +89,10 @@ MODULE_PARM_DESC(nopnp, "Do not use PNP to detect controller settings");
static bool i8042_debug;
module_param_named(debug, i8042_debug, bool, 0600);
MODULE_PARM_DESC(debug, "Turn i8042 debugging mode on and off");
+
+static bool i8042_unmask_kbd_data;
+module_param_named(unmask_kbd_data, i8042_unmask_kbd_data, bool, 0600);
+MODULE_PARM_DESC(unmask_kbd_data, "Unconditional enable (may reveal sensitive data) of normally sanitize-filtered kbd data traffic debug log [pre-condition: i8042.debug=1 enabled]");
#endif
static bool i8042_bypass_aux_irq_test;
@@ -116,6 +121,7 @@ struct i8042_port {
struct serio *serio;
int irq;
bool exists;
+ bool driver_bound;
signed char mux;
};
@@ -133,6 +139,7 @@ static bool i8042_kbd_irq_registered;
static bool i8042_aux_irq_registered;
static unsigned char i8042_suppress_kbd_ack;
static struct platform_device *i8042_platform_device;
+static struct notifier_block i8042_kbd_bind_notifier_block;
static irqreturn_t i8042_interrupt(int irq, void *dev_id);
static bool (*i8042_platform_filter)(unsigned char data, unsigned char str,
@@ -528,10 +535,10 @@ static irqreturn_t i8042_interrupt(int irq, void *dev_id)
port = &i8042_ports[port_no];
serio = port->exists ? port->serio : NULL;
- dbg("%02x <- i8042 (interrupt, %d, %d%s%s)\n",
- data, port_no, irq,
- dfl & SERIO_PARITY ? ", bad parity" : "",
- dfl & SERIO_TIMEOUT ? ", timeout" : "");
+ filter_dbg(port->driver_bound, data, "<- i8042 (interrupt, %d, %d%s%s)\n",
+ port_no, irq,
+ dfl & SERIO_PARITY ? ", bad parity" : "",
+ dfl & SERIO_TIMEOUT ? ", timeout" : "");
filtered = i8042_filter(data, str, serio);
@@ -871,7 +878,7 @@ static int __init i8042_check_aux(void)
static int i8042_controller_check(void)
{
if (i8042_flush()) {
- pr_err("No controller found\n");
+ pr_info("No controller found\n");
return -ENODEV;
}
@@ -1164,7 +1171,8 @@ static int i8042_pm_suspend(struct device *dev)
{
int i;
- i8042_controller_reset(true);
+ if (pm_suspend_via_firmware())
+ i8042_controller_reset(true);
/* Set up serio interrupts for system wakeup. */
for (i = 0; i < I8042_NUM_PORTS; i++) {
@@ -1177,8 +1185,17 @@ static int i8042_pm_suspend(struct device *dev)
return 0;
}
+static int i8042_pm_resume_noirq(struct device *dev)
+{
+ if (!pm_resume_via_firmware())
+ i8042_interrupt(0, NULL);
+
+ return 0;
+}
+
static int i8042_pm_resume(struct device *dev)
{
+ bool force_reset;
int i;
for (i = 0; i < I8042_NUM_PORTS; i++) {
@@ -1189,11 +1206,21 @@ static int i8042_pm_resume(struct device *dev)
}
/*
- * On resume from S2R we always try to reset the controller
- * to bring it in a sane state. (In case of S2D we expect
- * BIOS to reset the controller for us.)
+ * If platform firmware was not going to be involved in suspend, we did
+ * not restore the controller state to whatever it had been at boot
+ * time, so we do not need to do anything.
*/
- return i8042_controller_resume(true);
+ if (!pm_suspend_via_firmware())
+ return 0;
+
+ /*
+ * We only need to reset the controller if we are resuming after handing
+ * off control to the platform firmware, otherwise we can simply restore
+ * the mode.
+ */
+ force_reset = pm_resume_via_firmware();
+
+ return i8042_controller_resume(force_reset);
}
static int i8042_pm_thaw(struct device *dev)
@@ -1217,6 +1244,7 @@ static int i8042_pm_restore(struct device *dev)
static const struct dev_pm_ops i8042_pm_ops = {
.suspend = i8042_pm_suspend,
+ .resume_noirq = i8042_pm_resume_noirq,
.resume = i8042_pm_resume,
.thaw = i8042_pm_thaw,
.poweroff = i8042_pm_reset,
@@ -1438,6 +1466,29 @@ static int __init i8042_setup_kbd(void)
return error;
}
+static int i8042_kbd_bind_notifier(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct device *dev = data;
+ struct serio *serio = to_serio_port(dev);
+ struct i8042_port *port = serio->port_data;
+
+ if (serio != i8042_ports[I8042_KBD_PORT_NO].serio)
+ return 0;
+
+ switch (action) {
+ case BUS_NOTIFY_BOUND_DRIVER:
+ port->driver_bound = true;
+ break;
+
+ case BUS_NOTIFY_UNBIND_DRIVER:
+ port->driver_bound = false;
+ break;
+ }
+
+ return 0;
+}
+
static int __init i8042_probe(struct platform_device *dev)
{
int error;
@@ -1507,6 +1558,10 @@ static struct platform_driver i8042_driver = {
.shutdown = i8042_shutdown,
};
+static struct notifier_block i8042_kbd_bind_notifier_block = {
+ .notifier_call = i8042_kbd_bind_notifier,
+};
+
static int __init i8042_init(void)
{
struct platform_device *pdev;
@@ -1528,6 +1583,7 @@ static int __init i8042_init(void)
goto err_platform_exit;
}
+ bus_register_notifier(&serio_bus, &i8042_kbd_bind_notifier_block);
panic_blink = i8042_panic_blink;
return 0;
@@ -1543,6 +1599,7 @@ static void __exit i8042_exit(void)
platform_driver_unregister(&i8042_driver);
i8042_platform_exit();
+ bus_unregister_notifier(&serio_bus, &i8042_kbd_bind_notifier_block);
panic_blink = NULL;
}
diff --git a/kernel/drivers/input/serio/i8042.h b/kernel/drivers/input/serio/i8042.h
index fc080beff..1db0a40c9 100644
--- a/kernel/drivers/input/serio/i8042.h
+++ b/kernel/drivers/input/serio/i8042.h
@@ -73,6 +73,17 @@ static unsigned long i8042_start_time;
printk(KERN_DEBUG KBUILD_MODNAME ": [%d] " format, \
(int) (jiffies - i8042_start_time), ##arg); \
} while (0)
+
+#define filter_dbg(filter, data, format, args...) \
+ do { \
+ if (!i8042_debug) \
+ break; \
+ \
+ if (!filter || i8042_unmask_kbd_data) \
+ dbg("%02x " format, data, ##args); \
+ else \
+ dbg("** " format, ##args); \
+ } while (0)
#else
#define dbg_init() do { } while (0)
#define dbg(format, arg...) \
@@ -80,6 +91,8 @@ static unsigned long i8042_start_time;
if (0) \
printk(KERN_DEBUG pr_fmt(format), ##arg); \
} while (0)
+
+#define filter_dbg(filter, data, format, args...) do { } while (0)
#endif
#endif /* _I8042_H */
diff --git a/kernel/drivers/input/serio/libps2.c b/kernel/drivers/input/serio/libps2.c
index 75516996d..316f2c897 100644
--- a/kernel/drivers/input/serio/libps2.c
+++ b/kernel/drivers/input/serio/libps2.c
@@ -212,12 +212,17 @@ int __ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command)
* time before the ACK arrives.
*/
if (ps2_sendbyte(ps2dev, command & 0xff,
- command == PS2_CMD_RESET_BAT ? 1000 : 200))
- goto out;
+ command == PS2_CMD_RESET_BAT ? 1000 : 200)) {
+ serio_pause_rx(ps2dev->serio);
+ goto out_reset_flags;
+ }
- for (i = 0; i < send; i++)
- if (ps2_sendbyte(ps2dev, param[i], 200))
- goto out;
+ for (i = 0; i < send; i++) {
+ if (ps2_sendbyte(ps2dev, param[i], 200)) {
+ serio_pause_rx(ps2dev->serio);
+ goto out_reset_flags;
+ }
+ }
/*
* The reset command takes a long time to execute.
@@ -234,17 +239,18 @@ int __ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command)
!(ps2dev->flags & PS2_FLAG_CMD), timeout);
}
+ serio_pause_rx(ps2dev->serio);
+
if (param)
for (i = 0; i < receive; i++)
param[i] = ps2dev->cmdbuf[(receive - 1) - i];
if (ps2dev->cmdcnt && (command != PS2_CMD_RESET_BAT || ps2dev->cmdcnt != 1))
- goto out;
+ goto out_reset_flags;
rc = 0;
- out:
- serio_pause_rx(ps2dev->serio);
+ out_reset_flags:
ps2dev->flags = 0;
serio_continue_rx(ps2dev->serio);
diff --git a/kernel/drivers/input/serio/parkbd.c b/kernel/drivers/input/serio/parkbd.c
index 26b45936f..1edfac78d 100644
--- a/kernel/drivers/input/serio/parkbd.c
+++ b/kernel/drivers/input/serio/parkbd.c
@@ -141,19 +141,16 @@ static void parkbd_interrupt(void *dev_id)
parkbd_last = jiffies;
}
-static int parkbd_getport(void)
+static int parkbd_getport(struct parport *pp)
{
- struct parport *pp;
+ struct pardev_cb parkbd_parport_cb;
- pp = parport_find_number(parkbd_pp_no);
+ memset(&parkbd_parport_cb, 0, sizeof(parkbd_parport_cb));
+ parkbd_parport_cb.irq_func = parkbd_interrupt;
+ parkbd_parport_cb.flags = PARPORT_FLAG_EXCL;
- if (pp == NULL) {
- printk(KERN_ERR "parkbd: no such parport\n");
- return -ENODEV;
- }
-
- parkbd_dev = parport_register_device(pp, "parkbd", NULL, NULL, parkbd_interrupt, PARPORT_DEV_EXCL, NULL);
- parport_put_port(pp);
+ parkbd_dev = parport_register_dev_model(pp, "parkbd",
+ &parkbd_parport_cb, 0);
if (!parkbd_dev)
return -ENODEV;
@@ -168,7 +165,7 @@ static int parkbd_getport(void)
return 0;
}
-static struct serio * __init parkbd_allocate_serio(void)
+static struct serio *parkbd_allocate_serio(void)
{
struct serio *serio;
@@ -183,18 +180,21 @@ static struct serio * __init parkbd_allocate_serio(void)
return serio;
}
-static int __init parkbd_init(void)
+static void parkbd_attach(struct parport *pp)
{
- int err;
+ if (pp->number != parkbd_pp_no) {
+ pr_debug("Not using parport%d.\n", pp->number);
+ return;
+ }
- err = parkbd_getport();
- if (err)
- return err;
+ if (parkbd_getport(pp))
+ return;
parkbd_port = parkbd_allocate_serio();
if (!parkbd_port) {
parport_release(parkbd_dev);
- return -ENOMEM;
+ parport_unregister_device(parkbd_dev);
+ return;
}
parkbd_writelines(3);
@@ -204,14 +204,35 @@ static int __init parkbd_init(void)
printk(KERN_INFO "serio: PARKBD %s adapter on %s\n",
parkbd_mode ? "AT" : "XT", parkbd_dev->port->name);
- return 0;
+ return;
}
-static void __exit parkbd_exit(void)
+static void parkbd_detach(struct parport *port)
{
+ if (!parkbd_port || port->number != parkbd_pp_no)
+ return;
+
parport_release(parkbd_dev);
serio_unregister_port(parkbd_port);
parport_unregister_device(parkbd_dev);
+ parkbd_port = NULL;
+}
+
+static struct parport_driver parkbd_parport_driver = {
+ .name = "parkbd",
+ .match_port = parkbd_attach,
+ .detach = parkbd_detach,
+ .devmodel = true,
+};
+
+static int __init parkbd_init(void)
+{
+ return parport_register_driver(&parkbd_parport_driver);
+}
+
+static void __exit parkbd_exit(void)
+{
+ parport_unregister_driver(&parkbd_parport_driver);
}
module_init(parkbd_init);
diff --git a/kernel/drivers/input/serio/serio.c b/kernel/drivers/input/serio/serio.c
index a05a5179d..8f828975a 100644
--- a/kernel/drivers/input/serio/serio.c
+++ b/kernel/drivers/input/serio/serio.c
@@ -49,8 +49,6 @@ static DEFINE_MUTEX(serio_mutex);
static LIST_HEAD(serio_list);
-static struct bus_type serio_bus;
-
static void serio_add_port(struct serio *serio);
static int serio_reconnect_port(struct serio *serio);
static void serio_disconnect_port(struct serio *serio);
@@ -1017,7 +1015,7 @@ irqreturn_t serio_interrupt(struct serio *serio,
}
EXPORT_SYMBOL(serio_interrupt);
-static struct bus_type serio_bus = {
+struct bus_type serio_bus = {
.name = "serio",
.drv_groups = serio_driver_groups,
.match = serio_bus_match,
@@ -1029,6 +1027,7 @@ static struct bus_type serio_bus = {
.pm = &serio_pm_ops,
#endif
};
+EXPORT_SYMBOL(serio_bus);
static int __init serio_init(void)
{
diff --git a/kernel/drivers/input/serio/serport.c b/kernel/drivers/input/serio/serport.c
index 69175b825..9c927d35c 100644
--- a/kernel/drivers/input/serio/serport.c
+++ b/kernel/drivers/input/serio/serport.c
@@ -167,7 +167,6 @@ static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, u
{
struct serport *serport = (struct serport*) tty->disc_data;
struct serio *serio;
- char name[64];
if (test_and_set_bit(SERPORT_BUSY, &serport->flags))
return -EBUSY;
@@ -177,7 +176,7 @@ static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, u
return -ENOMEM;
strlcpy(serio->name, "Serial port", sizeof(serio->name));
- snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty, name));
+ snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty));
serio->id = serport->id;
serio->id.type = SERIO_RS232;
serio->write = serport_serio_write;
@@ -187,7 +186,7 @@ static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, u
serio->dev.parent = tty->dev;
serio_register_port(serport->serio);
- printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty, name));
+ printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty));
wait_event_interruptible(serport->wait, test_bit(SERPORT_DEAD, &serport->flags));
serio_unregister_port(serport->serio);
diff --git a/kernel/drivers/input/serio/userio.c b/kernel/drivers/input/serio/userio.c
new file mode 100644
index 000000000..df1fd4186
--- /dev/null
+++ b/kernel/drivers/input/serio/userio.c
@@ -0,0 +1,285 @@
+/*
+ * userio kernel serio device emulation module
+ * Copyright (C) 2015 Red Hat
+ * Copyright (C) 2015 Stephen Chandler Paul <thatslyude@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * 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 Lesser
+ * General Public License for more details.
+ */
+
+#include <linux/circ_buf.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/serio.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/sched.h>
+#include <linux/poll.h>
+#include <uapi/linux/userio.h>
+
+#define USERIO_NAME "userio"
+#define USERIO_BUFSIZE 16
+
+static struct miscdevice userio_misc;
+
+struct userio_device {
+ struct serio *serio;
+ struct mutex mutex;
+
+ bool running;
+
+ u8 head;
+ u8 tail;
+
+ spinlock_t buf_lock;
+ unsigned char buf[USERIO_BUFSIZE];
+
+ wait_queue_head_t waitq;
+};
+
+/**
+ * userio_device_write - Write data from serio to a userio device in userspace
+ * @id: The serio port for the userio device
+ * @val: The data to write to the device
+ */
+static int userio_device_write(struct serio *id, unsigned char val)
+{
+ struct userio_device *userio = id->port_data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&userio->buf_lock, flags);
+
+ userio->buf[userio->head] = val;
+ userio->head = (userio->head + 1) % USERIO_BUFSIZE;
+
+ if (userio->head == userio->tail)
+ dev_warn(userio_misc.this_device,
+ "Buffer overflowed, userio client isn't keeping up");
+
+ spin_unlock_irqrestore(&userio->buf_lock, flags);
+
+ wake_up_interruptible(&userio->waitq);
+
+ return 0;
+}
+
+static int userio_char_open(struct inode *inode, struct file *file)
+{
+ struct userio_device *userio;
+
+ userio = kzalloc(sizeof(struct userio_device), GFP_KERNEL);
+ if (!userio)
+ return -ENOMEM;
+
+ mutex_init(&userio->mutex);
+ spin_lock_init(&userio->buf_lock);
+ init_waitqueue_head(&userio->waitq);
+
+ userio->serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
+ if (!userio->serio) {
+ kfree(userio);
+ return -ENOMEM;
+ }
+
+ userio->serio->write = userio_device_write;
+ userio->serio->port_data = userio;
+
+ file->private_data = userio;
+
+ return 0;
+}
+
+static int userio_char_release(struct inode *inode, struct file *file)
+{
+ struct userio_device *userio = file->private_data;
+
+ if (userio->running) {
+ /*
+ * Don't free the serio port here, serio_unregister_port()
+ * does it for us.
+ */
+ serio_unregister_port(userio->serio);
+ } else {
+ kfree(userio->serio);
+ }
+
+ kfree(userio);
+
+ return 0;
+}
+
+static ssize_t userio_char_read(struct file *file, char __user *user_buffer,
+ size_t count, loff_t *ppos)
+{
+ struct userio_device *userio = file->private_data;
+ int error;
+ size_t nonwrap_len, copylen;
+ unsigned char buf[USERIO_BUFSIZE];
+ unsigned long flags;
+
+ /*
+ * By the time we get here, the data that was waiting might have
+ * been taken by another thread. Grab the buffer lock and check if
+ * there's still any data waiting, otherwise repeat this process
+ * until we have data (unless the file descriptor is non-blocking
+ * of course).
+ */
+ for (;;) {
+ spin_lock_irqsave(&userio->buf_lock, flags);
+
+ nonwrap_len = CIRC_CNT_TO_END(userio->head,
+ userio->tail,
+ USERIO_BUFSIZE);
+ copylen = min(nonwrap_len, count);
+ if (copylen) {
+ memcpy(buf, &userio->buf[userio->tail], copylen);
+ userio->tail = (userio->tail + copylen) %
+ USERIO_BUFSIZE;
+ }
+
+ spin_unlock_irqrestore(&userio->buf_lock, flags);
+
+ if (nonwrap_len)
+ break;
+
+ /* buffer was/is empty */
+ if (file->f_flags & O_NONBLOCK)
+ return -EAGAIN;
+
+ /*
+ * count == 0 is special - no IO is done but we check
+ * for error conditions (see above).
+ */
+ if (count == 0)
+ return 0;
+
+ error = wait_event_interruptible(userio->waitq,
+ userio->head != userio->tail);
+ if (error)
+ return error;
+ }
+
+ if (copylen)
+ if (copy_to_user(user_buffer, buf, copylen))
+ return -EFAULT;
+
+ return copylen;
+}
+
+static ssize_t userio_char_write(struct file *file, const char __user *buffer,
+ size_t count, loff_t *ppos)
+{
+ struct userio_device *userio = file->private_data;
+ struct userio_cmd cmd;
+ int error;
+
+ if (count != sizeof(cmd)) {
+ dev_warn(userio_misc.this_device, "Invalid payload size\n");
+ return -EINVAL;
+ }
+
+ if (copy_from_user(&cmd, buffer, sizeof(cmd)))
+ return -EFAULT;
+
+ error = mutex_lock_interruptible(&userio->mutex);
+ if (error)
+ return error;
+
+ switch (cmd.type) {
+ case USERIO_CMD_REGISTER:
+ if (!userio->serio->id.type) {
+ dev_warn(userio_misc.this_device,
+ "No port type given on /dev/userio\n");
+
+ error = -EINVAL;
+ goto out;
+ }
+
+ if (userio->running) {
+ dev_warn(userio_misc.this_device,
+ "Begin command sent, but we're already running\n");
+ error = -EBUSY;
+ goto out;
+ }
+
+ userio->running = true;
+ serio_register_port(userio->serio);
+ break;
+
+ case USERIO_CMD_SET_PORT_TYPE:
+ if (userio->running) {
+ dev_warn(userio_misc.this_device,
+ "Can't change port type on an already running userio instance\n");
+ error = -EBUSY;
+ goto out;
+ }
+
+ userio->serio->id.type = cmd.data;
+ break;
+
+ case USERIO_CMD_SEND_INTERRUPT:
+ if (!userio->running) {
+ dev_warn(userio_misc.this_device,
+ "The device must be registered before sending interrupts\n");
+ error = -ENODEV;
+ goto out;
+ }
+
+ serio_interrupt(userio->serio, cmd.data, 0);
+ break;
+
+ default:
+ error = -EOPNOTSUPP;
+ goto out;
+ }
+
+out:
+ mutex_unlock(&userio->mutex);
+ return error ?: count;
+}
+
+static unsigned int userio_char_poll(struct file *file, poll_table *wait)
+{
+ struct userio_device *userio = file->private_data;
+
+ poll_wait(file, &userio->waitq, wait);
+
+ if (userio->head != userio->tail)
+ return POLLIN | POLLRDNORM;
+
+ return 0;
+}
+
+static const struct file_operations userio_fops = {
+ .owner = THIS_MODULE,
+ .open = userio_char_open,
+ .release = userio_char_release,
+ .read = userio_char_read,
+ .write = userio_char_write,
+ .poll = userio_char_poll,
+ .llseek = no_llseek,
+};
+
+static struct miscdevice userio_misc = {
+ .fops = &userio_fops,
+ .minor = USERIO_MINOR,
+ .name = USERIO_NAME,
+};
+module_driver(userio_misc, misc_register, misc_deregister);
+
+MODULE_ALIAS_MISCDEV(USERIO_MINOR);
+MODULE_ALIAS("devname:" USERIO_NAME);
+
+MODULE_AUTHOR("Stephen Chandler Paul <thatslyude@gmail.com>");
+MODULE_DESCRIPTION("Virtual Serio Device Support");
+MODULE_LICENSE("GPL");