minix3/servers/input/input.c

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2020-02-21 00:59:27 +05:30
/* Keyboard/mouse input server. */
#include <minix/drivers.h>
#include <minix/chardriver.h>
#include <minix/ds.h>
#include <sys/ioctl.h>
#include <sys/kbdio.h>
#include "input.h"
#define INPUT_DEBUG 0
static int input_open(devminor_t, int, endpoint_t);
static int input_close(devminor_t);
static ssize_t input_read(devminor_t, u64_t, endpoint_t, cp_grant_id_t, size_t,
int, cdev_id_t);
static int input_ioctl(devminor_t, unsigned long, endpoint_t, cp_grant_id_t,
int, endpoint_t, cdev_id_t);
static int input_cancel(devminor_t, endpoint_t, cdev_id_t);
static int input_select(devminor_t, unsigned int, endpoint_t);
static void input_other(message *, int);
static struct input_dev devs[INPUT_DEV_MAX];
#define input_dev_active(dev) ((dev)->owner != NONE || \
(dev)->minor == KBDMUX_MINOR || \
(dev)->minor == MOUSEMUX_MINOR)
#define input_dev_buf_empty(dev) ((dev)->count == 0)
#define input_dev_buf_full(dev) ((dev)->count == EVENTBUF_SIZE)
/* Entry points to the input driver. */
static struct chardriver input_tab = {
.cdr_open = input_open,
.cdr_close = input_close,
.cdr_read = input_read,
.cdr_ioctl = input_ioctl,
.cdr_cancel = input_cancel,
.cdr_select = input_select,
.cdr_other = input_other
};
/*
* Map a minor number to an input device structure.
*/
static struct input_dev *
input_map(devminor_t minor)
{
/*
* The minor device numbers were chosen not to be equal to the array
* slots, so that more keyboards can be added without breaking backward
* compatibility later.
*/
if (minor == KBDMUX_MINOR)
return &devs[KBDMUX_DEV];
else if (minor >= KBD0_MINOR && minor < KBD0_MINOR + KBD_MINORS)
return &devs[FIRST_KBD_DEV + (minor - KBD0_MINOR)];
else if (minor == MOUSEMUX_MINOR)
return &devs[MOUSEMUX_DEV];
else if (minor >= MOUSE0_MINOR && minor < MOUSE0_MINOR + MOUSE_MINORS)
return &devs[FIRST_MOUSE_DEV + (minor - MOUSE0_MINOR)];
else
return NULL;
}
/*
* Map an input device structure index to a minor number.
*/
static devminor_t
input_revmap(int id)
{
if (id == KBDMUX_DEV)
return KBDMUX_MINOR;
else if (id >= FIRST_KBD_DEV && id <= LAST_KBD_DEV)
return KBD0_MINOR + (id - FIRST_KBD_DEV);
else if (id == MOUSEMUX_DEV)
return MOUSEMUX_MINOR;
else if (id >= FIRST_MOUSE_DEV && id <= LAST_MOUSE_DEV)
return MOUSE0_MINOR + (id - FIRST_MOUSE_DEV);
else
panic("reverse-mapping invalid ID %d", id);
}
/*
* Open an input device.
*/
static int
input_open(devminor_t minor, int UNUSED(access), endpoint_t UNUSED(user_endpt))
{
struct input_dev *input_dev;
if ((input_dev = input_map(minor)) == NULL)
return ENXIO;
if (!input_dev_active(input_dev))
return ENXIO;
if (input_dev->opened)
return EBUSY;
input_dev->opened = TRUE;
return OK;
}
/*
* Close an input device.
*/
static int
input_close(devminor_t minor)
{
struct input_dev *input_dev;
if ((input_dev = input_map(minor)) == NULL)
return ENXIO;
if (!input_dev->opened) {
printf("INPUT: closing already-closed device %d\n", minor);
return EINVAL;
}
input_dev->opened = FALSE;
input_dev->tail = 0;
input_dev->count = 0;
return OK;
}
/*
* Copy input events to a reader.
*/
static ssize_t
input_copy_events(endpoint_t endpt, cp_grant_id_t grant,
unsigned int event_count, struct input_dev *input_dev)
{
int r, nbytes, wrap_left;
size_t event_size = sizeof(*input_dev->eventbuf);
if (input_dev->count < event_count)
panic("input_copy_events: not enough input is ready");
wrap_left = input_dev->tail + event_count - EVENTBUF_SIZE;
nbytes = (wrap_left <= 0 ? event_count :
EVENTBUF_SIZE - input_dev->tail) * event_size;
if ((r = sys_safecopyto(endpt, grant, 0,
(vir_bytes)(input_dev->eventbuf + input_dev->tail), nbytes)) != OK)
return r;
/* Copy possible remaining part if we wrap over. */
if (wrap_left > 0 && (r = sys_safecopyto(endpt, grant, nbytes,
(vir_bytes) input_dev->eventbuf, wrap_left * event_size)) != OK)
return r;
input_dev->tail = (input_dev->tail + event_count) % EVENTBUF_SIZE;
input_dev->count -= event_count;
return event_size * event_count; /* bytes copied */
}
/*
* Read from an input device.
*/
static ssize_t
input_read(devminor_t minor, u64_t UNUSED(position), endpoint_t endpt,
cp_grant_id_t grant, size_t size, int flags, cdev_id_t id)
{
unsigned int event_count;
struct input_dev *input_dev;
if ((input_dev = input_map(minor)) == NULL)
return ENXIO;
/* We cannot accept more than one pending read request at once. */
if (!input_dev_active(input_dev) || input_dev->suspended)
return EIO;
/* The caller's buffer must have room for at least one whole event. */
event_count = size / sizeof(*input_dev->eventbuf);
if (event_count == 0)
return EIO;
/* No data available? Suspend the caller, unless we shouldn't block. */
if (input_dev_buf_empty(input_dev)) {
if (flags & CDEV_NONBLOCK)
return EAGAIN;
input_dev->suspended = TRUE;
input_dev->caller = endpt;
input_dev->grant = grant;
input_dev->req_id = id;
/* We should now wake up any selector, but that's lame.. */
return EDONTREPLY;
}
if (event_count > input_dev->count)
event_count = input_dev->count;
return input_copy_events(endpt, grant, event_count, input_dev);
}
/*
* Set keyboard LEDs on one or all keyboards.
*/
static void
input_set_leds(devminor_t minor, unsigned int mask)
{
struct input_dev *dev;
message m;
int i, r;
/* Prepare the request message */
memset(&m, 0, sizeof(m));
m.m_type = INPUT_SETLEDS;
m.m_input_linputdriver_setleds.led_mask = mask;
/*
* Send the request to all matching keyboard devices. As side effect,
* this approach discards the request on mouse devices.
*/
for (i = FIRST_KBD_DEV; i <= LAST_KBD_DEV; i++) {
dev = &devs[i];
if (minor != KBDMUX_MINOR && minor != dev->minor)
continue;
/* Save the new state; the driver might (re)start later. */
dev->leds = mask;
if (dev->owner != NONE) {
if ((r = asynsend3(dev->owner, &m, AMF_NOREPLY)) != OK)
printf("INPUT: asynsend to %u failed (%d)\n",
dev->owner, r);
}
}
}
/*
* Process an IOCTL request.
*/
static int
input_ioctl(devminor_t minor, unsigned long request, endpoint_t endpt,
cp_grant_id_t grant, int flags, endpoint_t user_endpt, cdev_id_t id)
{
struct input_dev *input_dev;
kio_leds_t leds;
unsigned int mask;
int r;
if ((input_dev = input_map(minor)) == NULL)
return ENXIO;
if (!input_dev_active(input_dev))
return EIO;
switch (request) {
case KIOCSLEDS:
if ((r = sys_safecopyfrom(endpt, grant, 0, (vir_bytes) &leds,
sizeof(leds))) != OK)
return r;
mask = 0;
if (leds.kl_bits & KBD_LEDS_NUM)
mask |= (1 << INPUT_LED_NUMLOCK);
if (leds.kl_bits & KBD_LEDS_CAPS)
mask |= (1 << INPUT_LED_CAPSLOCK);
if (leds.kl_bits & KBD_LEDS_SCROLL)
mask |= (1 << INPUT_LED_SCROLLLOCK);
input_set_leds(minor, mask);
return OK;
default:
return ENOTTY;
}
}
/*
* Cancel a suspended read request.
*/
static int
input_cancel(devminor_t minor, endpoint_t endpt, cdev_id_t id)
{
struct input_dev *input_dev;
if ((input_dev = input_map(minor)) == NULL)
return ENXIO;
if (input_dev->suspended && input_dev->caller == endpt &&
input_dev->req_id == id) {
input_dev->suspended = FALSE;
return EINTR;
}
return EDONTREPLY;
}
/*
* Perform a select call on an input device.
*/
static int
input_select(devminor_t minor, unsigned int ops, endpoint_t endpt)
{
struct input_dev *input_dev;
int ready_ops;
if ((input_dev = input_map(minor)) == NULL)
return ENXIO;
ready_ops = 0;
if (ops & CDEV_OP_RD) {
if (!input_dev_active(input_dev) || input_dev->suspended)
ready_ops |= CDEV_OP_RD; /* immediate error */
else if (!input_dev_buf_empty(input_dev))
ready_ops |= CDEV_OP_RD; /* data available */
else if (ops & CDEV_NOTIFY)
input_dev->selector = endpt; /* report later */
}
if (ops & CDEV_OP_WR) ready_ops |= CDEV_OP_WR; /* immediate error */
return ready_ops;
}
/*
* An input device receives an input event. Enqueue it, and possibly unsuspend
* a read request or wake up a selector.
*/
static void
input_process(struct input_dev *input_dev, const message *m)
{
unsigned int next;
int r;
if (input_dev_buf_full(input_dev)) {
/* Overflow. Overwrite the oldest event. */
input_dev->tail = (input_dev->tail + 1) % EVENTBUF_SIZE;
input_dev->count--;
#if INPUT_DEBUG
printf("INPUT: overflow on device %u\n", input_dev - devs);
#endif
}
next = (input_dev->tail + input_dev->count) % EVENTBUF_SIZE;
input_dev->eventbuf[next].page = m->m_linputdriver_input_event.page;
input_dev->eventbuf[next].code = m->m_linputdriver_input_event.code;
input_dev->eventbuf[next].value = m->m_linputdriver_input_event.value;
input_dev->eventbuf[next].flags = m->m_linputdriver_input_event.flags;
input_dev->eventbuf[next].devid = m->m_linputdriver_input_event.id;
input_dev->eventbuf[next].rsvd[0] = 0;
input_dev->eventbuf[next].rsvd[1] = 0;
input_dev->count++;
/*
* There is new input. Revive a suspended reader if there was one.
* Otherwise see if we should reply to a select query.
*/
if (input_dev->suspended) {
r = input_copy_events(input_dev->caller, input_dev->grant, 1,
input_dev);
chardriver_reply_task(input_dev->caller, input_dev->req_id, r);
input_dev->suspended = FALSE;
} else if (input_dev->selector != NONE) {
chardriver_reply_select(input_dev->selector, input_dev->minor,
CDEV_OP_RD);
input_dev->selector = NONE;
}
}
/*
* An input event has arrived from a driver.
*/
static void
input_event(message *m)
{
struct input_dev *input_dev, *mux_dev;
int r, id;
/* Unlike minor numbers, device IDs are in fact array indices. */
id = m->m_linputdriver_input_event.id;
if (id < 0 || id >= INPUT_DEV_MAX)
return;
/* The sender must owner the device. */
input_dev = &devs[id];
if (input_dev->owner != m->m_source)
return;
/* Input events are also delivered to the respective multiplexer. */
if (input_dev->minor >= KBD0_MINOR &&
input_dev->minor < KBD0_MINOR + KBD_MINORS)
mux_dev = &devs[KBDMUX_DEV];
else
mux_dev = &devs[MOUSEMUX_DEV];
/*
* Try to deliver the event to the input device or otherwise the
* corresponding multiplexer. If neither are opened, forward the event
* to TTY.
*/
if (input_dev->opened)
input_process(input_dev, m);
else if (mux_dev->opened)
input_process(mux_dev, m);
else {
message fwd;
mess_input_tty_event *tty_event = &(fwd.m_input_tty_event);
fwd.m_type = TTY_INPUT_EVENT;
tty_event->id = m->m_linputdriver_input_event.id;
tty_event->page = m->m_linputdriver_input_event.page;
tty_event->code = m->m_linputdriver_input_event.code;
tty_event->value = m->m_linputdriver_input_event.value;
tty_event->flags = m->m_linputdriver_input_event.flags;
if ((r = ipc_send(TTY_PROC_NR, &fwd)) != OK)
printf("INPUT: send to TTY failed (%d)\n", r);
}
}
/*
* Allocate a device structure for an input driver of the given type, and
* return its ID. If the given label already owns a device ID of the right
* type, update that entry instead. If no device ID could be allocated, return
* INVALID_INPUT_ID.
*/
static int
input_alloc_id(int mouse, endpoint_t owner, const char *label)
{
int n, id, start, end;
if (!mouse) {
start = FIRST_KBD_DEV;
end = LAST_KBD_DEV;
} else {
start = FIRST_MOUSE_DEV;
end = LAST_MOUSE_DEV;
}
id = INVALID_INPUT_ID;
for (n = start; n <= end; n++) {
if (devs[n].owner != NONE) {
if (!strcmp(devs[n].label, label)) {
devs[n].owner = owner;
return n;
}
/* Do not allocate the ID of a disconnected but open device. */
} else if (!devs[n].opened && id == INVALID_INPUT_ID) {
id = n;
}
}
if (id != INVALID_INPUT_ID) {
devs[id].owner = owner;
strlcpy(devs[id].label, label, sizeof(devs[id].label));
#if INPUT_DEBUG
printf("INPUT: connected device %u to %u (%s)\n", id,
owner, label);
#endif
} else {
printf("INPUT: out of %s slots for new driver %d\n",
mouse ? "mouse" : "keyboard", owner);
}
return id;
}
/*
* Register keyboard and/or a mouse devices for a driver.
*/
static void
input_connect(endpoint_t owner, char *labelp, int typemask)
{
message m;
char label[DS_MAX_KEYLEN];
int r, kbd_id, mouse_id;
#if INPUT_DEBUG
printf("INPUT: connect request from %u (%s) for mask %x\n", owner,
labelp, typemask);
#endif
/* Check the driver's label. */
if ((r = ds_retrieve_label_name(label, owner)) != OK) {
printf("INPUT: unable to get label for %u: %d\n", owner, r);
return;
}
if (strcmp(label, labelp)) {
printf("INPUT: ignoring driver %s label %s\n", label, labelp);
return;
}
kbd_id = INVALID_INPUT_ID;
mouse_id = INVALID_INPUT_ID;
/*
* We ignore allocation failures here, thus possibly sending invalid
* IDs to the driver even for either or both the devices types it
* requested. As a result, the driver will not send us input for these
* device types, possibly effectively disabling the driver altogether.
* Theoretically we could still admit events to the multiplexers for
* such drivers, but that would lead to unexpected behavior with
* respect to keyboard LEDs, for example.
*/
if (typemask & INPUT_DEV_KBD)
kbd_id = input_alloc_id(FALSE /*mouse*/, owner, label);
if (typemask & INPUT_DEV_MOUSE)
mouse_id = input_alloc_id(TRUE /*mouse*/, owner, label);
memset(&m, 0, sizeof(m));
m.m_type = INPUT_CONF;
m.m_input_linputdriver_input_conf.kbd_id = kbd_id;
m.m_input_linputdriver_input_conf.mouse_id = mouse_id;
m.m_input_linputdriver_input_conf.rsvd1_id = INVALID_INPUT_ID; /* reserved (joystick?) */
m.m_input_linputdriver_input_conf.rsvd2_id = INVALID_INPUT_ID; /* reserved for future use */
if ((r = asynsend3(owner, &m, AMF_NOREPLY)) != OK)
printf("INPUT: asynsend to %u failed (%d)\n", owner, r);
/* If a keyboard was registered, also set its initial LED state. */
if (kbd_id != INVALID_INPUT_ID)
input_set_leds(devs[kbd_id].minor, devs[kbd_id].leds);
}
/*
* Disconnect a device.
*/
static void
input_disconnect(struct input_dev *input_dev)
{
#if INPUT_DEBUG
printf("INPUT: disconnected device %u\n", input_dev - devs);
#endif
if (input_dev->suspended) {
chardriver_reply_task(input_dev->caller, input_dev->req_id,
EIO);
input_dev->suspended = FALSE;
}
if (input_dev->selector != NONE) {
chardriver_reply_select(input_dev->selector, input_dev->minor,
CDEV_OP_RD);
input_dev->selector = NONE;
}
input_dev->owner = NONE;
}
/*
* Check for driver status changes in the data store.
*/
static void
input_check(void)
{
char key[DS_MAX_KEYLEN], *label;
const char *driver_prefix = "drv.inp.";
u32_t value;
size_t len;
int i, r, type;
endpoint_t owner;
len = strlen(driver_prefix);
/* Check for new (input driver) entries. */
while (ds_check(key, &type, &owner) == OK) {
if ((r = ds_retrieve_u32(key, &value)) != OK) {
printf("INPUT: ds_retrieve_u32 failed (%d)\n", r);
continue;
}
/* Only check for input driver registration events. */
if (strncmp(key, driver_prefix, len))
continue;
/* The prefix is followed by the driver's own label. */
label = &key[len];
input_connect(owner, label, value);
}
/* Check for removed (label) entries. */
for (i = 0; i < INPUT_DEV_MAX; i++) {
/* This also skips the multiplexers. */
if (devs[i].owner == NONE)
continue;
r = ds_retrieve_label_endpt(devs[i].label, &owner);
if (r == OK)
devs[i].owner = owner; /* not really necessary */
else if (r == ESRCH)
input_disconnect(&devs[i]);
else
printf("INPUT: ds_retrieve_label_endpt failed (%d)\n",
r);
}
}
/*
* Process messages not part of the character driver protocol.
*/
static void
input_other(message *m, int ipc_status)
{
if (is_ipc_notify(ipc_status)) {
switch (m->m_source) {
case DS_PROC_NR:
input_check();
break;
default:
printf("INPUT: unexpected notify from %d\n",
m->m_source);
}
return;
}
/* An input event from a registered driver. */
switch (m->m_type) {
case INPUT_EVENT:
input_event(m);
break;
case INPUT_SETLEDS:
if (m->m_source == TTY_PROC_NR) {
input_set_leds(KBDMUX_MINOR, m->m_input_linputdriver_setleds.led_mask);
break;
}
/* FALLTHROUGH */
default:
printf("INPUT: unexpected message %d from %d\n",
m->m_type, m->m_source);
}
}
/*
* Initialize the input server.
*/
static int
input_init(int UNUSED(type), sef_init_info_t *UNUSED(info))
{
message m;
int i, r;
/* Initialize input device structures. */
for (i = 0; i < INPUT_DEV_MAX; i++) {
devs[i].minor = input_revmap(i);
devs[i].owner = NONE;
devs[i].tail = 0;
devs[i].count = 0;
devs[i].opened = FALSE;
devs[i].suspended = FALSE;
devs[i].selector = NONE;
devs[i].leds = 0;
}
/* Subscribe to driver registration events for input drivers. */
if ((r = ds_subscribe("drv\\.inp\\..*", DSF_INITIAL)) != OK)
panic("INPUT: can't subscribe to driver events (%d)", r);
/* Announce our presence to VFS. */
chardriver_announce();
/* Announce our presence to TTY. */
memset(&m, 0, sizeof(m));
m.m_type = TTY_INPUT_UP;
if ((r = ipc_send(TTY_PROC_NR, &m)) != OK)
printf("INPUT: send to TTY failed (%d)\n", r);
return OK;
}
/*
* Set callbacks and invoke SEF startup.
*/
static void
input_startup(void)
{
sef_setcb_init_fresh(input_init);
sef_startup();
}
/*
* Main program of the input server.
*/
int
main(void)
{
input_startup();
chardriver_task(&input_tab);
return 0;
}