#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/sched/signal.h>
#include <linux/wait.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/mutex.h>
#include <linux/tty.h>
#include <linux/serial.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/idr.h>
#include <linux/fs.h>
#include <linux/kdev_t.h>
#include <linux/kfifo.h>
#include <linux/workqueue.h>
#include <linux/completion.h>
#include <linux/greybus.h>
#include "gbphy.h"
#define GB_NUM_MINORS 16
#define GB_NAME "ttyGB"
#define GB_UART_WRITE_FIFO_SIZE PAGE_SIZE
#define GB_UART_WRITE_ROOM_MARGIN 1
#define GB_UART_FIRMWARE_CREDITS 4096
#define GB_UART_CREDIT_WAIT_TIMEOUT_MSEC 10000
struct gb_tty {
struct gbphy_device *gbphy_dev;
struct tty_port port;
void *buffer;
size_t buffer_payload_max;
struct gb_connection *connection;
u16 cport_id;
unsigned int minor;
unsigned char clocal;
bool disconnected;
spinlock_t read_lock;
spinlock_t write_lock;
struct async_icount iocount;
struct async_icount oldcount;
wait_queue_head_t wioctl;
struct mutex mutex;
u8 ctrlin;
u8 ctrlout;
struct gb_uart_set_line_coding_request line_coding;
struct work_struct tx_work;
struct kfifo write_fifo;
bool close_pending;
unsigned int credits;
struct completion credits_complete;
};
static struct tty_driver *gb_tty_driver;
static DEFINE_IDR(tty_minors);
static DEFINE_MUTEX(table_lock);
static int gb_uart_receive_data_handler(struct gb_operation *op)
{
struct gb_connection *connection = op->connection;
struct gb_tty *gb_tty = gb_connection_get_data(connection);
struct tty_port *port = &gb_tty->port;
struct gb_message *request = op->request;
struct gb_uart_recv_data_request *receive_data;
u16 recv_data_size;
int count;
unsigned long tty_flags = TTY_NORMAL;
if (request->payload_size < sizeof(*receive_data)) {
dev_err(&gb_tty->gbphy_dev->dev,
"short receive-data request received (%zu < %zu)\n",
request->payload_size, sizeof(*receive_data));
return -EINVAL;
}
receive_data = op->request->payload;
recv_data_size = le16_to_cpu(receive_data->size);
if (recv_data_size != request->payload_size - sizeof(*receive_data)) {
dev_err(&gb_tty->gbphy_dev->dev,
"malformed receive-data request received (%u != %zu)\n",
recv_data_size,
request->payload_size - sizeof(*receive_data));
return -EINVAL;
}
if (!recv_data_size)
return -EINVAL;
if (receive_data->flags) {
if (receive_data->flags & GB_UART_RECV_FLAG_BREAK)
tty_flags = TTY_BREAK;
else if (receive_data->flags & GB_UART_RECV_FLAG_PARITY)
tty_flags = TTY_PARITY;
else if (receive_data->flags & GB_UART_RECV_FLAG_FRAMING)
tty_flags = TTY_FRAME;
if (receive_data->flags & GB_UART_RECV_FLAG_OVERRUN)
tty_insert_flip_char(port, 0, TTY_OVERRUN);
}
count = tty_insert_flip_string_fixed_flag(port, receive_data->data,
tty_flags, recv_data_size);
if (count != recv_data_size) {
dev_err(&gb_tty->gbphy_dev->dev,
"UART: RX 0x%08x bytes only wrote 0x%08x\n",
recv_data_size, count);
}
if (count)
tty_flip_buffer_push(port);
return 0;
}
static int gb_uart_serial_state_handler(struct gb_operation *op)
{
struct gb_connection *connection = op->connection;
struct gb_tty *gb_tty = gb_connection_get_data(connection);
struct gb_message *request = op->request;
struct gb_uart_serial_state_request *serial_state;
if (request->payload_size < sizeof(*serial_state)) {
dev_err(&gb_tty->gbphy_dev->dev,
"short serial-state event received (%zu < %zu)\n",
request->payload_size, sizeof(*serial_state));
return -EINVAL;
}
serial_state = request->payload;
gb_tty->ctrlin = serial_state->control;
return 0;
}
static int gb_uart_receive_credits_handler(struct gb_operation *op)
{
struct gb_connection *connection = op->connection;
struct gb_tty *gb_tty = gb_connection_get_data(connection);
struct gb_message *request = op->request;
struct gb_uart_receive_credits_request *credit_request;
unsigned long flags;
unsigned int incoming_credits;
int ret = 0;
if (request->payload_size < sizeof(*credit_request)) {
dev_err(&gb_tty->gbphy_dev->dev,
"short receive_credits event received (%zu < %zu)\n",
request->payload_size,
sizeof(*credit_request));
return -EINVAL;
}
credit_request = request->payload;
incoming_credits = le16_to_cpu(credit_request->count);
spin_lock_irqsave(&gb_tty->write_lock, flags);
gb_tty->credits += incoming_credits;
if (gb_tty->credits > GB_UART_FIRMWARE_CREDITS) {
gb_tty->credits -= incoming_credits;
ret = -EINVAL;
}
spin_unlock_irqrestore(&gb_tty->write_lock, flags);
if (ret) {
dev_err(&gb_tty->gbphy_dev->dev,
"invalid number of incoming credits: %d\n",
incoming_credits);
return ret;
}
if (!gb_tty->close_pending)
schedule_work(&gb_tty->tx_work);
tty_port_tty_wakeup(&gb_tty->port);
if (gb_tty->credits == GB_UART_FIRMWARE_CREDITS)
complete(&gb_tty->credits_complete);
return ret;
}
static int gb_uart_request_handler(struct gb_operation *op)
{
struct gb_connection *connection = op->connection;
struct gb_tty *gb_tty = gb_connection_get_data(connection);
int type = op->type;
int ret;
switch (type) {
case GB_UART_TYPE_RECEIVE_DATA:
ret = gb_uart_receive_data_handler(op);
break;
case GB_UART_TYPE_SERIAL_STATE:
ret = gb_uart_serial_state_handler(op);
break;
case GB_UART_TYPE_RECEIVE_CREDITS:
ret = gb_uart_receive_credits_handler(op);
break;
default:
dev_err(&gb_tty->gbphy_dev->dev,
"unsupported unsolicited request: 0x%02x\n", type);
ret = -EINVAL;
}
return ret;
}
static void gb_uart_tx_write_work(struct work_struct *work)
{
struct gb_uart_send_data_request *request;
struct gb_tty *gb_tty;
unsigned long flags;
unsigned int send_size;
int ret;
gb_tty = container_of(work, struct gb_tty, tx_work);
request = gb_tty->buffer;
while (1) {
if (gb_tty->close_pending)
break;
spin_lock_irqsave(&gb_tty->write_lock, flags);
send_size = gb_tty->buffer_payload_max;
if (send_size > gb_tty->credits)
send_size = gb_tty->credits;
send_size = kfifo_out_peek(&gb_tty->write_fifo,
&request->data[0],
send_size);
if (!send_size) {
spin_unlock_irqrestore(&gb_tty->write_lock, flags);
break;
}
gb_tty->credits -= send_size;
spin_unlock_irqrestore(&gb_tty->write_lock, flags);
request->size = cpu_to_le16(send_size);
ret = gb_operation_sync(gb_tty->connection,
GB_UART_TYPE_SEND_DATA,
request, sizeof(*request) + send_size,
NULL, 0);
if (ret) {
dev_err(&gb_tty->gbphy_dev->dev,
"send data error: %d\n", ret);
spin_lock_irqsave(&gb_tty->write_lock, flags);
gb_tty->credits += send_size;
spin_unlock_irqrestore(&gb_tty->write_lock, flags);
if (!gb_tty->close_pending)
schedule_work(work);
return;
}
spin_lock_irqsave(&gb_tty->write_lock, flags);
ret = kfifo_out(&gb_tty->write_fifo, &request->data[0],
send_size);
spin_unlock_irqrestore(&gb_tty->write_lock, flags);
tty_port_tty_wakeup(&gb_tty->port);
}
}
static int send_line_coding(struct gb_tty *tty)
{
return gb_operation_sync(tty->connection, GB_UART_TYPE_SET_LINE_CODING,
&tty->line_coding, sizeof(tty->line_coding),
NULL, 0);
}
static int send_control(struct gb_tty *gb_tty, u8 control)
{
struct gb_uart_set_control_line_state_request request;
request.control = control;
return gb_operation_sync(gb_tty->connection,
GB_UART_TYPE_SET_CONTROL_LINE_STATE,
&request, sizeof(request), NULL, 0);
}
static int send_break(struct gb_tty *gb_tty, u8 state)
{
struct gb_uart_set_break_request request;
if ((state != 0) && (state != 1)) {
dev_err(&gb_tty->gbphy_dev->dev,
"invalid break state of %d\n", state);
return -EINVAL;
}
request.state = state;
return gb_operation_sync(gb_tty->connection, GB_UART_TYPE_SEND_BREAK,
&request, sizeof(request), NULL, 0);
}
static int gb_uart_wait_for_all_credits(struct gb_tty *gb_tty)
{
int ret;
if (gb_tty->credits == GB_UART_FIRMWARE_CREDITS)
return 0;
ret = wait_for_completion_timeout(&gb_tty->credits_complete,
msecs_to_jiffies(GB_UART_CREDIT_WAIT_TIMEOUT_MSEC));
if (!ret) {
dev_err(&gb_tty->gbphy_dev->dev,
"time out waiting for credits\n");
return -ETIMEDOUT;
}
return 0;
}
static int gb_uart_flush(struct gb_tty *gb_tty, u8 flags)
{
struct gb_uart_serial_flush_request request;
request.flags = flags;
return gb_operation_sync(gb_tty->connection, GB_UART_TYPE_FLUSH_FIFOS,
&request, sizeof(request), NULL, 0);
}
static struct gb_tty *get_gb_by_minor(unsigned int minor)
{
struct gb_tty *gb_tty;
mutex_lock(&table_lock);
gb_tty = idr_find(&tty_minors, minor);
if (gb_tty) {
mutex_lock(&gb_tty->mutex);
if (gb_tty->disconnected) {
mutex_unlock(&gb_tty->mutex);
gb_tty = NULL;
} else {
tty_port_get(&gb_tty->port);
mutex_unlock(&gb_tty->mutex);
}
}
mutex_unlock(&table_lock);
return gb_tty;
}
static int alloc_minor(struct gb_tty *gb_tty)
{
int minor;
mutex_lock(&table_lock);
minor = idr_alloc(&tty_minors, gb_tty, 0, GB_NUM_MINORS, GFP_KERNEL);
mutex_unlock(&table_lock);
if (minor >= 0)
gb_tty->minor = minor;
return minor;
}
static void release_minor(struct gb_tty *gb_tty)
{
int minor = gb_tty->minor;
gb_tty->minor = 0;
mutex_lock(&table_lock);
idr_remove(&tty_minors, minor);
mutex_unlock(&table_lock);
}
static int gb_tty_install(struct tty_driver *driver, struct tty_struct *tty)
{
struct gb_tty *gb_tty;
int retval;
gb_tty = get_gb_by_minor(tty->index);
if (!gb_tty)
return -ENODEV;
retval = tty_standard_install(driver, tty);
if (retval)
goto error;
tty->driver_data = gb_tty;
return 0;
error:
tty_port_put(&gb_tty->port);
return retval;
}
static int gb_tty_open(struct tty_struct *tty, struct file *file)
{
struct gb_tty *gb_tty = tty->driver_data;
return tty_port_open(&gb_tty->port, tty, file);
}
static void gb_tty_close(struct tty_struct *tty, struct file *file)
{
struct gb_tty *gb_tty = tty->driver_data;
tty_port_close(&gb_tty->port, tty, file);
}
static void gb_tty_cleanup(struct tty_struct *tty)
{
struct gb_tty *gb_tty = tty->driver_data;
tty_port_put(&gb_tty->port);
}
static void gb_tty_hangup(struct tty_struct *tty)
{
struct gb_tty *gb_tty = tty->driver_data;
tty_port_hangup(&gb_tty->port);
}
static ssize_t gb_tty_write(struct tty_struct *tty, const u8 *buf, size_t count)
{
struct gb_tty *gb_tty = tty->driver_data;
count = kfifo_in_spinlocked(&gb_tty->write_fifo, buf, count,
&gb_tty->write_lock);
if (count && !gb_tty->close_pending)
schedule_work(&gb_tty->tx_work);
return count;
}
static unsigned int gb_tty_write_room(struct tty_struct *tty)
{
struct gb_tty *gb_tty = tty->driver_data;
unsigned long flags;
int room;
spin_lock_irqsave(&gb_tty->write_lock, flags);
room = kfifo_avail(&gb_tty->write_fifo);
spin_unlock_irqrestore(&gb_tty->write_lock, flags);
room -= GB_UART_WRITE_ROOM_MARGIN;
if (room < 0)
return 0;
return room;
}
static unsigned int gb_tty_chars_in_buffer(struct tty_struct *tty)
{
struct gb_tty *gb_tty = tty->driver_data;
unsigned long flags;
unsigned int chars;
spin_lock_irqsave(&gb_tty->write_lock, flags);
chars = kfifo_len(&gb_tty->write_fifo);
if (gb_tty->credits < GB_UART_FIRMWARE_CREDITS)
chars += GB_UART_FIRMWARE_CREDITS - gb_tty->credits;
spin_unlock_irqrestore(&gb_tty->write_lock, flags);
return chars;
}
static int gb_tty_break_ctl(struct tty_struct *tty, int state)
{
struct gb_tty *gb_tty = tty->driver_data;
return send_break(gb_tty, state ? 1 : 0);
}
static void gb_tty_set_termios(struct tty_struct *tty,
const struct ktermios *termios_old)
{
struct gb_uart_set_line_coding_request newline;
struct gb_tty *gb_tty = tty->driver_data;
struct ktermios *termios = &tty->termios;
u8 newctrl = gb_tty->ctrlout;
newline.rate = cpu_to_le32(tty_get_baud_rate(tty));
newline.format = termios->c_cflag & CSTOPB ?
GB_SERIAL_2_STOP_BITS : GB_SERIAL_1_STOP_BITS;
newline.parity = termios->c_cflag & PARENB ?
(termios->c_cflag & PARODD ? 1 : 2) +
(termios->c_cflag & CMSPAR ? 2 : 0) : 0;
newline.data_bits = tty_get_char_size(termios->c_cflag);
gb_tty->clocal = ((termios->c_cflag & CLOCAL) != 0);
if (C_BAUD(tty) == B0) {
newline.rate = gb_tty->line_coding.rate;
newctrl &= ~(GB_UART_CTRL_DTR | GB_UART_CTRL_RTS);
} else if (termios_old && (termios_old->c_cflag & CBAUD) == B0) {
newctrl |= (GB_UART_CTRL_DTR | GB_UART_CTRL_RTS);
}
if (newctrl != gb_tty->ctrlout) {
gb_tty->ctrlout = newctrl;
send_control(gb_tty, newctrl);
}
if (C_CRTSCTS(tty) && C_BAUD(tty) != B0)
newline.flow_control = GB_SERIAL_AUTO_RTSCTS_EN;
else
newline.flow_control = 0;
if (memcmp(&gb_tty->line_coding, &newline, sizeof(newline))) {
memcpy(&gb_tty->line_coding, &newline, sizeof(newline));
send_line_coding(gb_tty);
}
}
static int gb_tty_tiocmget(struct tty_struct *tty)
{
struct gb_tty *gb_tty = tty->driver_data;
return (gb_tty->ctrlout & GB_UART_CTRL_DTR ? TIOCM_DTR : 0) |
(gb_tty->ctrlout & GB_UART_CTRL_RTS ? TIOCM_RTS : 0) |
(gb_tty->ctrlin & GB_UART_CTRL_DSR ? TIOCM_DSR : 0) |
(gb_tty->ctrlin & GB_UART_CTRL_RI ? TIOCM_RI : 0) |
(gb_tty->ctrlin & GB_UART_CTRL_DCD ? TIOCM_CD : 0) |
TIOCM_CTS;
}
static int gb_tty_tiocmset(struct tty_struct *tty, unsigned int set,
unsigned int clear)
{
struct gb_tty *gb_tty = tty->driver_data;
u8 newctrl = gb_tty->ctrlout;
set = (set & TIOCM_DTR ? GB_UART_CTRL_DTR : 0) |
(set & TIOCM_RTS ? GB_UART_CTRL_RTS : 0);
clear = (clear & TIOCM_DTR ? GB_UART_CTRL_DTR : 0) |
(clear & TIOCM_RTS ? GB_UART_CTRL_RTS : 0);
newctrl = (newctrl & ~clear) | set;
if (gb_tty->ctrlout == newctrl)
return 0;
gb_tty->ctrlout = newctrl;
return send_control(gb_tty, newctrl);
}
static void gb_tty_throttle(struct tty_struct *tty)
{
struct gb_tty *gb_tty = tty->driver_data;
unsigned char stop_char;
int retval;
if (I_IXOFF(tty)) {
stop_char = STOP_CHAR(tty);
retval = gb_tty_write(tty, &stop_char, 1);
if (retval <= 0)
return;
}
if (tty->termios.c_cflag & CRTSCTS) {
gb_tty->ctrlout &= ~GB_UART_CTRL_RTS;
retval = send_control(gb_tty, gb_tty->ctrlout);
}
}
static void gb_tty_unthrottle(struct tty_struct *tty)
{
struct gb_tty *gb_tty = tty->driver_data;
unsigned char start_char;
int retval;
if (I_IXOFF(tty)) {
start_char = START_CHAR(tty);
retval = gb_tty_write(tty, &start_char, 1);
if (retval <= 0)
return;
}
if (tty->termios.c_cflag & CRTSCTS) {
gb_tty->ctrlout |= GB_UART_CTRL_RTS;
retval = send_control(gb_tty, gb_tty->ctrlout);
}
}
static int get_serial_info(struct tty_struct *tty,
struct serial_struct *ss)
{
struct gb_tty *gb_tty = tty->driver_data;
ss->line = gb_tty->minor;
mutex_lock(&gb_tty->port.mutex);
ss->close_delay = jiffies_to_msecs(gb_tty->port.close_delay) / 10;
ss->closing_wait =
gb_tty->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
ASYNC_CLOSING_WAIT_NONE :
jiffies_to_msecs(gb_tty->port.closing_wait) / 10;
mutex_unlock(&gb_tty->port.mutex);
return 0;
}
static int set_serial_info(struct tty_struct *tty,
struct serial_struct *ss)
{
struct gb_tty *gb_tty = tty->driver_data;
unsigned int closing_wait;
unsigned int close_delay;
int retval = 0;
close_delay = msecs_to_jiffies(ss->close_delay * 10);
closing_wait = ss->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
ASYNC_CLOSING_WAIT_NONE :
msecs_to_jiffies(ss->closing_wait * 10);
mutex_lock(&gb_tty->port.mutex);
if (!capable(CAP_SYS_ADMIN)) {
if ((close_delay != gb_tty->port.close_delay) ||
(closing_wait != gb_tty->port.closing_wait))
retval = -EPERM;
} else {
gb_tty->port.close_delay = close_delay;
gb_tty->port.closing_wait = closing_wait;
}
mutex_unlock(&gb_tty->port.mutex);
return retval;
}
static int wait_serial_change(struct gb_tty *gb_tty, unsigned long arg)
{
int retval = 0;
DECLARE_WAITQUEUE(wait, current);
struct async_icount old;
struct async_icount new;
if (!(arg & (TIOCM_DSR | TIOCM_RI | TIOCM_CD)))
return -EINVAL;
do {
spin_lock_irq(&gb_tty->read_lock);
old = gb_tty->oldcount;
new = gb_tty->iocount;
gb_tty->oldcount = new;
spin_unlock_irq(&gb_tty->read_lock);
if ((arg & TIOCM_DSR) && (old.dsr != new.dsr))
break;
if ((arg & TIOCM_CD) && (old.dcd != new.dcd))
break;
if ((arg & TIOCM_RI) && (old.rng != new.rng))
break;
add_wait_queue(&gb_tty->wioctl, &wait);
set_current_state(TASK_INTERRUPTIBLE);
schedule();
remove_wait_queue(&gb_tty->wioctl, &wait);
if (gb_tty->disconnected) {
if (arg & TIOCM_CD)
break;
retval = -ENODEV;
} else if (signal_pending(current)) {
retval = -ERESTARTSYS;
}
} while (!retval);
return retval;
}
static int gb_tty_get_icount(struct tty_struct *tty,
struct serial_icounter_struct *icount)
{
struct gb_tty *gb_tty = tty->driver_data;
icount->dsr = gb_tty->iocount.dsr;
icount->rng = gb_tty->iocount.rng;
icount->dcd = gb_tty->iocount.dcd;
icount->frame = gb_tty->iocount.frame;
icount->overrun = gb_tty->iocount.overrun;
icount->parity = gb_tty->iocount.parity;
icount->brk = gb_tty->iocount.brk;
return 0;
}
static int gb_tty_ioctl(struct tty_struct *tty, unsigned int cmd,
unsigned long arg)
{
struct gb_tty *gb_tty = tty->driver_data;
switch (cmd) {
case TIOCMIWAIT:
return wait_serial_change(gb_tty, arg);
}
return -ENOIOCTLCMD;
}
static void gb_tty_dtr_rts(struct tty_port *port, bool active)
{
struct gb_tty *gb_tty;
u8 newctrl;
gb_tty = container_of(port, struct gb_tty, port);
newctrl = gb_tty->ctrlout;
if (active)
newctrl |= (GB_UART_CTRL_DTR | GB_UART_CTRL_RTS);
else
newctrl &= ~(GB_UART_CTRL_DTR | GB_UART_CTRL_RTS);
gb_tty->ctrlout = newctrl;
send_control(gb_tty, newctrl);
}
static int gb_tty_port_activate(struct tty_port *port,
struct tty_struct *tty)
{
struct gb_tty *gb_tty;
gb_tty = container_of(port, struct gb_tty, port);
return gbphy_runtime_get_sync(gb_tty->gbphy_dev);
}
static void gb_tty_port_shutdown(struct tty_port *port)
{
struct gb_tty *gb_tty;
unsigned long flags;
int ret;
gb_tty = container_of(port, struct gb_tty, port);
gb_tty->close_pending = true;
cancel_work_sync(&gb_tty->tx_work);
spin_lock_irqsave(&gb_tty->write_lock, flags);
kfifo_reset_out(&gb_tty->write_fifo);
spin_unlock_irqrestore(&gb_tty->write_lock, flags);
if (gb_tty->credits == GB_UART_FIRMWARE_CREDITS)
goto out;
ret = gb_uart_flush(gb_tty, GB_SERIAL_FLAG_FLUSH_TRANSMITTER);
if (ret) {
dev_err(&gb_tty->gbphy_dev->dev,
"error flushing transmitter: %d\n", ret);
}
gb_uart_wait_for_all_credits(gb_tty);
out:
gb_tty->close_pending = false;
gbphy_runtime_put_autosuspend(gb_tty->gbphy_dev);
}
static void gb_tty_port_destruct(struct tty_port *port)
{
struct gb_tty *gb_tty = container_of(port, struct gb_tty, port);
if (gb_tty->minor != GB_NUM_MINORS)
release_minor(gb_tty);
kfifo_free(&gb_tty->write_fifo);
kfree(gb_tty->buffer);
kfree(gb_tty);
}
static const struct tty_operations gb_ops = {
.install = gb_tty_install,
.open = gb_tty_open,
.close = gb_tty_close,
.cleanup = gb_tty_cleanup,
.hangup = gb_tty_hangup,
.write = gb_tty_write,
.write_room = gb_tty_write_room,
.ioctl = gb_tty_ioctl,
.throttle = gb_tty_throttle,
.unthrottle = gb_tty_unthrottle,
.chars_in_buffer = gb_tty_chars_in_buffer,
.break_ctl = gb_tty_break_ctl,
.set_termios = gb_tty_set_termios,
.tiocmget = gb_tty_tiocmget,
.tiocmset = gb_tty_tiocmset,
.get_icount = gb_tty_get_icount,
.set_serial = set_serial_info,
.get_serial = get_serial_info,
};
static const struct tty_port_operations gb_port_ops = {
.dtr_rts = gb_tty_dtr_rts,
.activate = gb_tty_port_activate,
.shutdown = gb_tty_port_shutdown,
.destruct = gb_tty_port_destruct,
};
static int gb_uart_probe(struct gbphy_device *gbphy_dev,
const struct gbphy_device_id *id)
{
struct gb_connection *connection;
size_t max_payload;
struct gb_tty *gb_tty;
struct device *tty_dev;
int retval;
int minor;
connection = gb_connection_create(gbphy_dev->bundle,
le16_to_cpu(gbphy_dev->cport_desc->id),
gb_uart_request_handler);
if (IS_ERR(connection))
return PTR_ERR(connection);
max_payload = gb_operation_get_payload_size_max(connection);
if (max_payload < sizeof(struct gb_uart_send_data_request)) {
retval = -EINVAL;
goto exit_connection_destroy;
}
gb_tty = kzalloc_obj(*gb_tty);
if (!gb_tty) {
retval = -ENOMEM;
goto exit_connection_destroy;
}
tty_port_init(&gb_tty->port);
gb_tty->port.ops = &gb_port_ops;
gb_tty->minor = GB_NUM_MINORS;
gb_tty->buffer_payload_max = max_payload -
sizeof(struct gb_uart_send_data_request);
gb_tty->buffer = kzalloc(gb_tty->buffer_payload_max, GFP_KERNEL);
if (!gb_tty->buffer) {
retval = -ENOMEM;
goto exit_put_port;
}
INIT_WORK(&gb_tty->tx_work, gb_uart_tx_write_work);
retval = kfifo_alloc(&gb_tty->write_fifo, GB_UART_WRITE_FIFO_SIZE,
GFP_KERNEL);
if (retval)
goto exit_put_port;
gb_tty->credits = GB_UART_FIRMWARE_CREDITS;
init_completion(&gb_tty->credits_complete);
minor = alloc_minor(gb_tty);
if (minor < 0) {
if (minor == -ENOSPC) {
dev_err(&gbphy_dev->dev,
"no more free minor numbers\n");
retval = -ENODEV;
} else {
retval = minor;
}
goto exit_put_port;
}
gb_tty->minor = minor;
spin_lock_init(&gb_tty->write_lock);
spin_lock_init(&gb_tty->read_lock);
init_waitqueue_head(&gb_tty->wioctl);
mutex_init(&gb_tty->mutex);
gb_tty->connection = connection;
gb_tty->gbphy_dev = gbphy_dev;
gb_connection_set_data(connection, gb_tty);
gb_gbphy_set_data(gbphy_dev, gb_tty);
retval = gb_connection_enable_tx(connection);
if (retval)
goto exit_put_port;
retval = send_control(gb_tty, gb_tty->ctrlout);
if (retval)
goto exit_connection_disable;
gb_tty->line_coding.rate = cpu_to_le32(9600);
gb_tty->line_coding.format = GB_SERIAL_1_STOP_BITS;
gb_tty->line_coding.parity = GB_SERIAL_NO_PARITY;
gb_tty->line_coding.data_bits = 8;
retval = send_line_coding(gb_tty);
if (retval)
goto exit_connection_disable;
retval = gb_connection_enable(connection);
if (retval)
goto exit_connection_disable;
tty_dev = tty_port_register_device(&gb_tty->port, gb_tty_driver, minor,
&gbphy_dev->dev);
if (IS_ERR(tty_dev)) {
retval = PTR_ERR(tty_dev);
goto exit_connection_disable;
}
gbphy_runtime_put_autosuspend(gbphy_dev);
return 0;
exit_connection_disable:
gb_connection_disable(connection);
exit_put_port:
tty_port_put(&gb_tty->port);
exit_connection_destroy:
gb_connection_destroy(connection);
return retval;
}
static void gb_uart_remove(struct gbphy_device *gbphy_dev)
{
struct gb_tty *gb_tty = gb_gbphy_get_data(gbphy_dev);
struct gb_connection *connection = gb_tty->connection;
int ret;
ret = gbphy_runtime_get_sync(gbphy_dev);
if (ret)
gbphy_runtime_get_noresume(gbphy_dev);
mutex_lock(&gb_tty->mutex);
gb_tty->disconnected = true;
wake_up_all(&gb_tty->wioctl);
mutex_unlock(&gb_tty->mutex);
tty_port_tty_vhangup(&gb_tty->port);
gb_connection_disable_rx(connection);
tty_unregister_device(gb_tty_driver, gb_tty->minor);
gb_connection_disable(connection);
gb_connection_destroy(connection);
tty_port_put(&gb_tty->port);
}
static int gb_tty_init(void)
{
int retval = 0;
gb_tty_driver = tty_alloc_driver(GB_NUM_MINORS, TTY_DRIVER_REAL_RAW |
TTY_DRIVER_DYNAMIC_DEV);
if (IS_ERR(gb_tty_driver)) {
pr_err("Can not allocate tty driver\n");
retval = -ENOMEM;
goto fail_unregister_dev;
}
gb_tty_driver->driver_name = "gb";
gb_tty_driver->name = GB_NAME;
gb_tty_driver->major = 0;
gb_tty_driver->minor_start = 0;
gb_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
gb_tty_driver->subtype = SERIAL_TYPE_NORMAL;
gb_tty_driver->init_termios = tty_std_termios;
gb_tty_driver->init_termios.c_cflag = B9600 | CS8 |
CREAD | HUPCL | CLOCAL;
tty_set_operations(gb_tty_driver, &gb_ops);
retval = tty_register_driver(gb_tty_driver);
if (retval) {
pr_err("Can not register tty driver: %d\n", retval);
goto fail_put_gb_tty;
}
return 0;
fail_put_gb_tty:
tty_driver_kref_put(gb_tty_driver);
fail_unregister_dev:
return retval;
}
static void gb_tty_exit(void)
{
tty_unregister_driver(gb_tty_driver);
tty_driver_kref_put(gb_tty_driver);
idr_destroy(&tty_minors);
}
static const struct gbphy_device_id gb_uart_id_table[] = {
{ GBPHY_PROTOCOL(GREYBUS_PROTOCOL_UART) },
{ },
};
MODULE_DEVICE_TABLE(gbphy, gb_uart_id_table);
static struct gbphy_driver uart_driver = {
.name = "uart",
.probe = gb_uart_probe,
.remove = gb_uart_remove,
.id_table = gb_uart_id_table,
};
static int gb_uart_driver_init(void)
{
int ret;
ret = gb_tty_init();
if (ret)
return ret;
ret = gb_gbphy_register(&uart_driver);
if (ret) {
gb_tty_exit();
return ret;
}
return 0;
}
module_init(gb_uart_driver_init);
static void gb_uart_driver_exit(void)
{
gb_gbphy_deregister(&uart_driver);
gb_tty_exit();
}
module_exit(gb_uart_driver_exit);
MODULE_DESCRIPTION("UART driver for the Greybus 'generic' UART module");
MODULE_LICENSE("GPL v2");
