Alan Cox | 9e48565 | 2008-10-13 10:37:07 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Tty port functions |
| 3 | */ |
| 4 | |
| 5 | #include <linux/types.h> |
| 6 | #include <linux/errno.h> |
| 7 | #include <linux/tty.h> |
| 8 | #include <linux/tty_driver.h> |
| 9 | #include <linux/tty_flip.h> |
Alan Cox | 3e61696 | 2009-01-02 13:45:26 +0000 | [diff] [blame^] | 10 | #include <linux/serial.h> |
Alan Cox | 9e48565 | 2008-10-13 10:37:07 +0100 | [diff] [blame] | 11 | #include <linux/timer.h> |
| 12 | #include <linux/string.h> |
| 13 | #include <linux/slab.h> |
| 14 | #include <linux/sched.h> |
| 15 | #include <linux/init.h> |
| 16 | #include <linux/wait.h> |
| 17 | #include <linux/bitops.h> |
| 18 | #include <linux/delay.h> |
| 19 | #include <linux/module.h> |
| 20 | |
| 21 | void tty_port_init(struct tty_port *port) |
| 22 | { |
| 23 | memset(port, 0, sizeof(*port)); |
| 24 | init_waitqueue_head(&port->open_wait); |
| 25 | init_waitqueue_head(&port->close_wait); |
| 26 | mutex_init(&port->mutex); |
Alan Cox | 4a90f09 | 2008-10-13 10:39:46 +0100 | [diff] [blame] | 27 | spin_lock_init(&port->lock); |
Alan Cox | 9e48565 | 2008-10-13 10:37:07 +0100 | [diff] [blame] | 28 | port->close_delay = (50 * HZ) / 100; |
| 29 | port->closing_wait = (3000 * HZ) / 100; |
| 30 | } |
| 31 | EXPORT_SYMBOL(tty_port_init); |
| 32 | |
| 33 | int tty_port_alloc_xmit_buf(struct tty_port *port) |
| 34 | { |
| 35 | /* We may sleep in get_zeroed_page() */ |
| 36 | mutex_lock(&port->mutex); |
| 37 | if (port->xmit_buf == NULL) |
| 38 | port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL); |
| 39 | mutex_unlock(&port->mutex); |
| 40 | if (port->xmit_buf == NULL) |
| 41 | return -ENOMEM; |
| 42 | return 0; |
| 43 | } |
| 44 | EXPORT_SYMBOL(tty_port_alloc_xmit_buf); |
| 45 | |
| 46 | void tty_port_free_xmit_buf(struct tty_port *port) |
| 47 | { |
| 48 | mutex_lock(&port->mutex); |
| 49 | if (port->xmit_buf != NULL) { |
| 50 | free_page((unsigned long)port->xmit_buf); |
| 51 | port->xmit_buf = NULL; |
| 52 | } |
| 53 | mutex_unlock(&port->mutex); |
| 54 | } |
| 55 | EXPORT_SYMBOL(tty_port_free_xmit_buf); |
| 56 | |
| 57 | |
Alan Cox | 4a90f09 | 2008-10-13 10:39:46 +0100 | [diff] [blame] | 58 | /** |
| 59 | * tty_port_tty_get - get a tty reference |
| 60 | * @port: tty port |
| 61 | * |
| 62 | * Return a refcount protected tty instance or NULL if the port is not |
| 63 | * associated with a tty (eg due to close or hangup) |
| 64 | */ |
| 65 | |
| 66 | struct tty_struct *tty_port_tty_get(struct tty_port *port) |
| 67 | { |
| 68 | unsigned long flags; |
| 69 | struct tty_struct *tty; |
| 70 | |
| 71 | spin_lock_irqsave(&port->lock, flags); |
| 72 | tty = tty_kref_get(port->tty); |
| 73 | spin_unlock_irqrestore(&port->lock, flags); |
| 74 | return tty; |
| 75 | } |
| 76 | EXPORT_SYMBOL(tty_port_tty_get); |
| 77 | |
| 78 | /** |
| 79 | * tty_port_tty_set - set the tty of a port |
| 80 | * @port: tty port |
| 81 | * @tty: the tty |
| 82 | * |
| 83 | * Associate the port and tty pair. Manages any internal refcounts. |
| 84 | * Pass NULL to deassociate a port |
| 85 | */ |
| 86 | |
| 87 | void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty) |
| 88 | { |
| 89 | unsigned long flags; |
| 90 | |
| 91 | spin_lock_irqsave(&port->lock, flags); |
| 92 | if (port->tty) |
| 93 | tty_kref_put(port->tty); |
Alan Cox | cb4bca3 | 2008-10-21 13:47:44 +0100 | [diff] [blame] | 94 | port->tty = tty_kref_get(tty); |
Alan Cox | 4a90f09 | 2008-10-13 10:39:46 +0100 | [diff] [blame] | 95 | spin_unlock_irqrestore(&port->lock, flags); |
| 96 | } |
| 97 | EXPORT_SYMBOL(tty_port_tty_set); |
Alan Cox | 31f3593 | 2009-01-02 13:45:05 +0000 | [diff] [blame] | 98 | |
| 99 | /** |
Alan Cox | 3e61696 | 2009-01-02 13:45:26 +0000 | [diff] [blame^] | 100 | * tty_port_hangup - hangup helper |
| 101 | * @port: tty port |
| 102 | * |
| 103 | * Perform port level tty hangup flag and count changes. Drop the tty |
| 104 | * reference. |
| 105 | */ |
| 106 | |
| 107 | void tty_port_hangup(struct tty_port *port) |
| 108 | { |
| 109 | unsigned long flags; |
| 110 | |
| 111 | spin_lock_irqsave(&port->lock, flags); |
| 112 | port->count = 0; |
| 113 | port->flags &= ~ASYNC_NORMAL_ACTIVE; |
| 114 | if (port->tty) |
| 115 | tty_kref_put(port->tty); |
| 116 | port->tty = NULL; |
| 117 | spin_unlock_irqrestore(&port->lock, flags); |
| 118 | wake_up_interruptible(&port->open_wait); |
| 119 | } |
| 120 | EXPORT_SYMBOL(tty_port_hangup); |
| 121 | |
| 122 | /** |
Alan Cox | 31f3593 | 2009-01-02 13:45:05 +0000 | [diff] [blame] | 123 | * tty_port_carrier_raised - carrier raised check |
| 124 | * @port: tty port |
| 125 | * |
| 126 | * Wrapper for the carrier detect logic. For the moment this is used |
| 127 | * to hide some internal details. This will eventually become entirely |
| 128 | * internal to the tty port. |
| 129 | */ |
| 130 | |
| 131 | int tty_port_carrier_raised(struct tty_port *port) |
| 132 | { |
| 133 | if (port->ops->carrier_raised == NULL) |
| 134 | return 1; |
| 135 | return port->ops->carrier_raised(port); |
| 136 | } |
| 137 | EXPORT_SYMBOL(tty_port_carrier_raised); |
Alan Cox | 5d951fb | 2009-01-02 13:45:19 +0000 | [diff] [blame] | 138 | |
| 139 | /** |
| 140 | * tty_port_raise_dtr_rts - Riase DTR/RTS |
| 141 | * @port: tty port |
| 142 | * |
| 143 | * Wrapper for the DTR/RTS raise logic. For the moment this is used |
| 144 | * to hide some internal details. This will eventually become entirely |
| 145 | * internal to the tty port. |
| 146 | */ |
| 147 | |
| 148 | void tty_port_raise_dtr_rts(struct tty_port *port) |
| 149 | { |
| 150 | if (port->ops->raise_dtr_rts) |
| 151 | port->ops->raise_dtr_rts(port); |
| 152 | } |
| 153 | EXPORT_SYMBOL(tty_port_raise_dtr_rts); |