From e68453ed28c550c448709473ab89cebafa0ee34e Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Fri, 15 Aug 2014 19:44:32 +0800 Subject: [PATCH] greybus: uart-gb: now builds, more framework added --- drivers/staging/greybus/uart-gb.c | 221 +++++++++++++++++++++++++++++++++++++- 1 file changed, 216 insertions(+), 5 deletions(-) diff --git a/drivers/staging/greybus/uart-gb.c b/drivers/staging/greybus/uart-gb.c index 792536c..13a23cd 100644 --- a/drivers/staging/greybus/uart-gb.c +++ b/drivers/staging/greybus/uart-gb.c @@ -1,18 +1,27 @@ /* - * I2C bridge driver for the Greybus "generic" I2C module. + * UART driver for the Greybus "generic" UART module. * * Copyright 2014 Google Inc. * * Released under the GPLv2 only. + * + * Heavily based on drivers/usb/class/cdc-acm.c and + * drivers/usb/serial/usb-serial.c. */ #include +#include #include +#include +#include #include +#include +#include #include #include #include #include +#include #include #include "greybus.h" @@ -27,9 +36,14 @@ struct gb_tty { unsigned char clocal; unsigned int throttled:1; unsigned int throttle_req:1; + bool disconnected; + int writesize; // FIXME - set this somehow. spinlock_t read_lock; spinlock_t write_lock; - // FIXME locking!!! + struct async_icount iocount; + struct async_icount oldcount; + wait_queue_head_t wioctl; + struct mutex mutex; }; static const struct greybus_device_id id_table[] = { @@ -47,6 +61,16 @@ static struct gb_tty *get_gb_by_minor(unsigned minor) 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; } @@ -123,7 +147,7 @@ static void gb_tty_hangup(struct tty_struct *tty) static int gb_tty_write(struct tty_struct *tty, const unsigned char *buf, int count) { - struct gb_tty *gb_tty = tty->driver_data; +// struct gb_tty *gb_tty = tty->driver_data; // FIXME - actually implement... @@ -132,7 +156,7 @@ static int gb_tty_write(struct tty_struct *tty, const unsigned char *buf, static int gb_tty_write_room(struct tty_struct *tty) { - struct gb_tty *gb_tty = tty->driver_data; +// struct gb_tty *gb_tty = tty->driver_data; // FIXME - how much do we want to say we have room for? return 0; @@ -140,12 +164,43 @@ static int gb_tty_write_room(struct tty_struct *tty) static int gb_tty_chars_in_buffer(struct tty_struct *tty) { - struct gb_tty *gb_tty = tty->driver_data; +// struct gb_tty *gb_tty = tty->driver_data; // FIXME - how many left to send? return 0; } +static int gb_tty_break_ctl(struct tty_struct *tty, int state) +{ +// struct gb_tty *gb_tty = tty->driver_data; + + // FIXME - send a break, if asked to... + return 0; +} + +static void gb_tty_set_termios(struct tty_struct *tty, struct ktermios *old) +{ + // FIXME - is this it??? + tty_termios_copy_hw(&tty->termios, old); +} + +static int gb_tty_tiocmget(struct tty_struct *tty) +{ +// struct gb_tty *gb_tty = tty->driver_data; + + // FIXME - get some tiocms! + return 0; +} + +static int gb_tty_tiocmset(struct tty_struct *tty, unsigned int set, + unsigned int clear) +{ +// struct gb_tty *gb_tty = tty->driver_data; + + // FIXME - set some tiocms! + return 0; +} + static void gb_tty_throttle(struct tty_struct *tty) { struct gb_tty *gb_tty = tty->driver_data; @@ -171,6 +226,148 @@ static void gb_tty_unthrottle(struct tty_struct *tty) } } +static int get_serial_info(struct gb_tty *gb_tty, + struct serial_struct __user *info) +{ + struct serial_struct tmp; + + if (!info) + return -EINVAL; + + memset(&tmp, 0, sizeof(tmp)); + tmp.flags = ASYNC_LOW_LATENCY; + tmp.xmit_fifo_size = gb_tty->writesize; + tmp.baud_base = 0; // FIXME + tmp.close_delay = gb_tty->port.close_delay / 10; + tmp.closing_wait = gb_tty->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ? + ASYNC_CLOSING_WAIT_NONE : gb_tty->port.closing_wait / 10; + + if (copy_to_user(info, &tmp, sizeof(tmp))) + return -EFAULT; + else + return 0; +} + +static int set_serial_info(struct gb_tty *gb_tty, + struct serial_struct __user *newinfo) +{ + struct serial_struct new_serial; + unsigned int closing_wait; + unsigned int close_delay; + int retval; + + if (copy_from_user(&new_serial, newinfo, sizeof(new_serial))) + return -EFAULT; + + close_delay = new_serial.close_delay * 10; + closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ? + ASYNC_CLOSING_WAIT_NONE : new_serial.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 + retval = -EOPNOTSUPP; + } 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_lock_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; + else + retval = -ENODEV; + } else { + if (signal_pending(current)) + retval = -ERESTARTSYS; + } + } while (!retval); + + return retval; +} + +static int get_serial_usage(struct gb_tty *gb_tty, + struct serial_icounter_struct __user *count) +{ + struct serial_icounter_struct icount; + int retval = 0; + + memset(&icount, 0, sizeof(icount)); + 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; + + if (copy_to_user(count, &icount, sizeof(icount)) > 0) + retval = -EFAULT; + + return retval; +} + +static int gb_tty_ioctl(struct tty_struct *tty, unsigned int cmd, + unsigned long arg) +{ + struct gb_tty *gb_tty = tty->driver_data; + int retval = -ENOIOCTLCMD; + + switch (cmd) { + case TIOCGSERIAL: + retval = get_serial_info(gb_tty, + (struct serial_struct __user *)arg); + break; + case TIOCSSERIAL: + retval = set_serial_info(gb_tty, + (struct serial_struct __user *)arg); + break; + case TIOCMIWAIT: + retval = wait_serial_change(gb_tty, arg); + break; + case TIOCGICOUNT: + retval = get_serial_usage(gb_tty, + (struct serial_icounter_struct __user *)arg); + break; + } + + return retval; +} + static const struct tty_operations gb_ops = { .install = gb_tty_install, @@ -212,6 +409,8 @@ static int tty_gb_probe(struct greybus_device *gdev, const struct greybus_device gb_tty->gdev = gdev; 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); /* FIXME - allocate gb buffers */ @@ -235,6 +434,16 @@ static void tty_gb_disconnect(struct greybus_device *gdev) struct gb_tty *gb_tty = greybus_get_drvdata(gdev); struct tty_struct *tty; + if (!gb_tty) + return; + + mutex_lock(&gb_tty->mutex); + gb_tty->disconnected = true; + + wake_up_all(&gb_tty->wioctl); + greybus_set_drvdata(gdev, NULL); + mutex_unlock(&gb_tty->mutex); + tty = tty_port_tty_get(&gb_tty->port); if (tty) { tty_vhangup(tty); @@ -244,6 +453,8 @@ static void tty_gb_disconnect(struct greybus_device *gdev) tty_unregister_device(gb_tty_driver, gb_tty->minor); + /* FIXME - free transmit / recieve buffers */ + tty_port_put(&gb_tty->port); } -- 2.7.4