+/*
+ * Routine which returns the baud rate of the tty
+ *
+ * Note that the baud_table needs to be kept in sync with the
+ * include/asm/termbits.h file.
+ */
+static const speed_t baud_table[] = {
+ 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
+ 9600, 19200, 38400, 57600, 115200, 230400, 460800,
+#ifdef __sparc__
+ 76800, 153600, 307200, 614400, 921600
+#else
+ 500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
+ 2500000, 3000000, 3500000, 4000000
+#endif
+};
+
+#ifndef __sparc__
+static const tcflag_t baud_bits[] = {
+ B0, B50, B75, B110, B134, B150, B200, B300, B600,
+ B1200, B1800, B2400, B4800, B9600, B19200, B38400,
+ B57600, B115200, B230400, B460800, B500000, B576000,
+ B921600, B1000000, B1152000, B1500000, B2000000, B2500000,
+ B3000000, B3500000, B4000000
+};
+#else
+static const tcflag_t baud_bits[] = {
+ B0, B50, B75, B110, B134, B150, B200, B300, B600,
+ B1200, B1800, B2400, B4800, B9600, B19200, B38400,
+ B57600, B115200, B230400, B460800, B76800, B153600,
+ B307200, B614400, B921600
+};
+#endif
+
+static int n_baud_table = ARRAY_SIZE(baud_table);
+
+/**
+ * tty_termios_baud_rate
+ * @termios: termios structure
+ *
+ * Convert termios baud rate data into a speed. This should be called
+ * with the termios lock held if this termios is a terminal termios
+ * structure. May change the termios data. Device drivers can call this
+ * function but should use ->c_[io]speed directly as they are updated.
+ *
+ * Locking: none
+ */
+
+speed_t tty_termios_baud_rate(struct ktermios *termios)
+{
+ unsigned int cbaud;
+
+ cbaud = termios->c_cflag & CBAUD;
+
+#ifdef BOTHER
+ /* Magic token for arbitary speed via c_ispeed/c_ospeed */
+ if (cbaud == BOTHER)
+ return termios->c_ospeed;
+#endif
+ if (cbaud & CBAUDEX) {
+ cbaud &= ~CBAUDEX;
+
+ if (cbaud < 1 || cbaud + 15 > n_baud_table)
+ termios->c_cflag &= ~CBAUDEX;
+ else
+ cbaud += 15;
+ }
+ return baud_table[cbaud];
+}
+
+EXPORT_SYMBOL(tty_termios_baud_rate);
+
+/**
+ * tty_termios_input_baud_rate
+ * @termios: termios structure
+ *
+ * Convert termios baud rate data into a speed. This should be called
+ * with the termios lock held if this termios is a terminal termios
+ * structure. May change the termios data. Device drivers can call this
+ * function but should use ->c_[io]speed directly as they are updated.
+ *
+ * Locking: none
+ */
+
+speed_t tty_termios_input_baud_rate(struct ktermios *termios)
+{
+#ifdef IBSHIFT
+ unsigned int cbaud = (termios->c_cflag >> IBSHIFT) & CBAUD;
+
+ if (cbaud == B0)
+ return tty_termios_baud_rate(termios);
+
+ /* Magic token for arbitary speed via c_ispeed*/
+ if (cbaud == BOTHER)
+ return termios->c_ispeed;
+
+ if (cbaud & CBAUDEX) {
+ cbaud &= ~CBAUDEX;
+
+ if (cbaud < 1 || cbaud + 15 > n_baud_table)
+ termios->c_cflag &= ~(CBAUDEX << IBSHIFT);
+ else
+ cbaud += 15;
+ }
+ return baud_table[cbaud];
+#else
+ return tty_termios_baud_rate(termios);
+#endif
+}
+
+EXPORT_SYMBOL(tty_termios_input_baud_rate);
+
+#ifdef BOTHER
+
+/**
+ * tty_termios_encode_baud_rate
+ * @termios: termios structure
+ * @ispeed: input speed
+ * @ospeed: output speed
+ *
+ * Encode the speeds set into the passed termios structure. This is
+ * used as a library helper for drivers os that they can report back
+ * the actual speed selected when it differs from the speed requested
+ *
+ * For now input and output speed must agree.
+ *
+ * Locking: Caller should hold termios lock. This is already held
+ * when calling this function from the driver termios handler.
+ */
+
+void tty_termios_encode_baud_rate(struct ktermios *termios, speed_t ibaud, speed_t obaud)
+{
+ int i = 0;
+ int ifound = 0, ofound = 0;
+
+ termios->c_ispeed = ibaud;
+ termios->c_ospeed = obaud;
+
+ termios->c_cflag &= ~CBAUD;
+ /* Identical speed means no input encoding (ie B0 << IBSHIFT)*/
+ if (termios->c_ispeed == termios->c_ospeed)
+ ifound = 1;
+
+ do {
+ if (obaud == baud_table[i]) {
+ termios->c_cflag |= baud_bits[i];
+ ofound = 1;
+ /* So that if ibaud == obaud we don't set it */
+ continue;
+ }
+ if (ibaud == baud_table[i]) {
+ termios->c_cflag |= (baud_bits[i] << IBSHIFT);
+ ifound = 1;
+ }
+ }
+ while(++i < n_baud_table);
+ if (!ofound)
+ termios->c_cflag |= BOTHER;
+ if (!ifound)
+ termios->c_cflag |= (BOTHER << IBSHIFT);
+}
+
+EXPORT_SYMBOL_GPL(tty_termios_encode_baud_rate);
+
+#endif
+
+/**
+ * tty_get_baud_rate - get tty bit rates
+ * @tty: tty to query
+ *
+ * Returns the baud rate as an integer for this terminal. The
+ * termios lock must be held by the caller and the terminal bit
+ * flags may be updated.
+ *
+ * Locking: none
+ */
+
+speed_t tty_get_baud_rate(struct tty_struct *tty)
+{
+ speed_t baud = tty_termios_baud_rate(tty->termios);
+
+ if (baud == 38400 && tty->alt_speed) {
+ if (!tty->warned) {
+ printk(KERN_WARNING "Use of setserial/setrocket to "
+ "set SPD_* flags is deprecated\n");
+ tty->warned = 1;
+ }
+ baud = tty->alt_speed;
+ }
+
+ return baud;
+}
+
+EXPORT_SYMBOL(tty_get_baud_rate);
+