From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- drivers/accessibility/speakup/spk_ttyio.c | 387 ++++++++++++++++++++++++++++++ 1 file changed, 387 insertions(+) create mode 100644 drivers/accessibility/speakup/spk_ttyio.c (limited to 'drivers/accessibility/speakup/spk_ttyio.c') diff --git a/drivers/accessibility/speakup/spk_ttyio.c b/drivers/accessibility/speakup/spk_ttyio.c new file mode 100644 index 0000000000..4c0a6e1f01 --- /dev/null +++ b/drivers/accessibility/speakup/spk_ttyio.c @@ -0,0 +1,387 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include + +#include "speakup.h" +#include "spk_types.h" +#include "spk_priv.h" + +struct spk_ldisc_data { + char buf; + struct completion completion; + bool buf_free; + struct spk_synth *synth; +}; + +/* + * This allows to catch within spk_ttyio_ldisc_open whether it is getting set + * on for a speakup-driven device. + */ +static struct tty_struct *speakup_tty; +/* This mutex serializes the use of such global speakup_tty variable */ +static DEFINE_MUTEX(speakup_tty_mutex); + +static int ser_to_dev(int ser, dev_t *dev_no) +{ + if (ser < 0 || ser > (255 - 64)) { + pr_err("speakup: Invalid ser param. Must be between 0 and 191 inclusive.\n"); + return -EINVAL; + } + + *dev_no = MKDEV(4, (64 + ser)); + return 0; +} + +static int get_dev_to_use(struct spk_synth *synth, dev_t *dev_no) +{ + /* use ser only when dev is not specified */ + if (strcmp(synth->dev_name, SYNTH_DEFAULT_DEV) || + synth->ser == SYNTH_DEFAULT_SER) + return tty_dev_name_to_number(synth->dev_name, dev_no); + + return ser_to_dev(synth->ser, dev_no); +} + +static int spk_ttyio_ldisc_open(struct tty_struct *tty) +{ + struct spk_ldisc_data *ldisc_data; + + if (tty != speakup_tty) + /* Somebody tried to use this line discipline outside speakup */ + return -ENODEV; + + if (!tty->ops->write) + return -EOPNOTSUPP; + + ldisc_data = kmalloc(sizeof(*ldisc_data), GFP_KERNEL); + if (!ldisc_data) + return -ENOMEM; + + init_completion(&ldisc_data->completion); + ldisc_data->buf_free = true; + tty->disc_data = ldisc_data; + + return 0; +} + +static void spk_ttyio_ldisc_close(struct tty_struct *tty) +{ + kfree(tty->disc_data); +} + +static size_t spk_ttyio_receive_buf2(struct tty_struct *tty, const u8 *cp, + const u8 *fp, size_t count) +{ + struct spk_ldisc_data *ldisc_data = tty->disc_data; + struct spk_synth *synth = ldisc_data->synth; + + if (synth->read_buff_add) { + unsigned int i; + + for (i = 0; i < count; i++) + synth->read_buff_add(cp[i]); + + return count; + } + + if (!ldisc_data->buf_free) + /* ttyio_in will tty_flip_buffer_push */ + return 0; + + /* Make sure the consumer has read buf before we have seen + * buf_free == true and overwrite buf + */ + mb(); + + ldisc_data->buf = cp[0]; + ldisc_data->buf_free = false; + complete(&ldisc_data->completion); + + return 1; +} + +static struct tty_ldisc_ops spk_ttyio_ldisc_ops = { + .owner = THIS_MODULE, + .num = N_SPEAKUP, + .name = "speakup_ldisc", + .open = spk_ttyio_ldisc_open, + .close = spk_ttyio_ldisc_close, + .receive_buf2 = spk_ttyio_receive_buf2, +}; + +static int spk_ttyio_out(struct spk_synth *in_synth, const char ch); +static int spk_ttyio_out_unicode(struct spk_synth *in_synth, u16 ch); +static void spk_ttyio_send_xchar(struct spk_synth *in_synth, char ch); +static void spk_ttyio_tiocmset(struct spk_synth *in_synth, unsigned int set, unsigned int clear); +static unsigned char spk_ttyio_in(struct spk_synth *in_synth); +static unsigned char spk_ttyio_in_nowait(struct spk_synth *in_synth); +static void spk_ttyio_flush_buffer(struct spk_synth *in_synth); +static int spk_ttyio_wait_for_xmitr(struct spk_synth *in_synth); + +struct spk_io_ops spk_ttyio_ops = { + .synth_out = spk_ttyio_out, + .synth_out_unicode = spk_ttyio_out_unicode, + .send_xchar = spk_ttyio_send_xchar, + .tiocmset = spk_ttyio_tiocmset, + .synth_in = spk_ttyio_in, + .synth_in_nowait = spk_ttyio_in_nowait, + .flush_buffer = spk_ttyio_flush_buffer, + .wait_for_xmitr = spk_ttyio_wait_for_xmitr, +}; +EXPORT_SYMBOL_GPL(spk_ttyio_ops); + +static inline void get_termios(struct tty_struct *tty, + struct ktermios *out_termios) +{ + down_read(&tty->termios_rwsem); + *out_termios = tty->termios; + up_read(&tty->termios_rwsem); +} + +static int spk_ttyio_initialise_ldisc(struct spk_synth *synth) +{ + int ret = 0; + struct tty_struct *tty; + struct ktermios tmp_termios; + dev_t dev; + + ret = get_dev_to_use(synth, &dev); + if (ret) + return ret; + + tty = tty_kopen_exclusive(dev); + if (IS_ERR(tty)) + return PTR_ERR(tty); + + if (tty->ops->open) + ret = tty->ops->open(tty, NULL); + else + ret = -ENODEV; + + if (ret) { + tty_unlock(tty); + return ret; + } + + clear_bit(TTY_HUPPED, &tty->flags); + /* ensure hardware flow control is enabled */ + get_termios(tty, &tmp_termios); + if (!(tmp_termios.c_cflag & CRTSCTS)) { + tmp_termios.c_cflag |= CRTSCTS; + tty_set_termios(tty, &tmp_termios); + /* + * check c_cflag to see if it's updated as tty_set_termios + * may not return error even when no tty bits are + * changed by the request. + */ + get_termios(tty, &tmp_termios); + if (!(tmp_termios.c_cflag & CRTSCTS)) + pr_warn("speakup: Failed to set hardware flow control\n"); + } + + tty_unlock(tty); + + mutex_lock(&speakup_tty_mutex); + speakup_tty = tty; + ret = tty_set_ldisc(tty, N_SPEAKUP); + speakup_tty = NULL; + mutex_unlock(&speakup_tty_mutex); + + if (!ret) { + /* Success */ + struct spk_ldisc_data *ldisc_data = tty->disc_data; + + ldisc_data->synth = synth; + synth->dev = tty; + return 0; + } + + pr_err("speakup: Failed to set N_SPEAKUP on tty\n"); + + tty_lock(tty); + if (tty->ops->close) + tty->ops->close(tty, NULL); + tty_unlock(tty); + + tty_kclose(tty); + + return ret; +} + +void spk_ttyio_register_ldisc(void) +{ + if (tty_register_ldisc(&spk_ttyio_ldisc_ops)) + pr_warn("speakup: Error registering line discipline. Most synths won't work.\n"); +} + +void spk_ttyio_unregister_ldisc(void) +{ + tty_unregister_ldisc(&spk_ttyio_ldisc_ops); +} + +static int spk_ttyio_out(struct spk_synth *in_synth, const char ch) +{ + struct tty_struct *tty = in_synth->dev; + int ret; + + if (!in_synth->alive || !tty->ops->write) + return 0; + + ret = tty->ops->write(tty, &ch, 1); + + if (ret == 0) + /* No room */ + return 0; + + if (ret > 0) + /* Success */ + return 1; + + pr_warn("%s: I/O error, deactivating speakup\n", + in_synth->long_name); + /* No synth any more, so nobody will restart TTYs, + * and we thus need to do it ourselves. Now that there + * is no synth we can let application flood anyway + */ + in_synth->alive = 0; + speakup_start_ttys(); + return 0; +} + +static int spk_ttyio_out_unicode(struct spk_synth *in_synth, u16 ch) +{ + int ret; + + if (ch < 0x80) { + ret = spk_ttyio_out(in_synth, ch); + } else if (ch < 0x800) { + ret = spk_ttyio_out(in_synth, 0xc0 | (ch >> 6)); + ret &= spk_ttyio_out(in_synth, 0x80 | (ch & 0x3f)); + } else { + ret = spk_ttyio_out(in_synth, 0xe0 | (ch >> 12)); + ret &= spk_ttyio_out(in_synth, 0x80 | ((ch >> 6) & 0x3f)); + ret &= spk_ttyio_out(in_synth, 0x80 | (ch & 0x3f)); + } + return ret; +} + +static void spk_ttyio_send_xchar(struct spk_synth *in_synth, char ch) +{ + struct tty_struct *tty = in_synth->dev; + + if (tty->ops->send_xchar) + tty->ops->send_xchar(tty, ch); +} + +static void spk_ttyio_tiocmset(struct spk_synth *in_synth, unsigned int set, unsigned int clear) +{ + struct tty_struct *tty = in_synth->dev; + + if (tty->ops->tiocmset) + tty->ops->tiocmset(tty, set, clear); +} + +static int spk_ttyio_wait_for_xmitr(struct spk_synth *in_synth) +{ + return 1; +} + +static unsigned char ttyio_in(struct spk_synth *in_synth, int timeout) +{ + struct tty_struct *tty = in_synth->dev; + struct spk_ldisc_data *ldisc_data = tty->disc_data; + char rv; + + if (!timeout) { + if (!try_wait_for_completion(&ldisc_data->completion)) + return 0xff; + } else if (wait_for_completion_timeout(&ldisc_data->completion, + usecs_to_jiffies(timeout)) == 0) { + pr_warn("spk_ttyio: timeout (%d) while waiting for input\n", + timeout); + return 0xff; + } + + rv = ldisc_data->buf; + /* Make sure we have read buf before we set buf_free to let + * the producer overwrite it + */ + mb(); + ldisc_data->buf_free = true; + /* Let TTY push more characters */ + tty_flip_buffer_push(tty->port); + + return rv; +} + +static unsigned char spk_ttyio_in(struct spk_synth *in_synth) +{ + return ttyio_in(in_synth, SPK_SYNTH_TIMEOUT); +} + +static unsigned char spk_ttyio_in_nowait(struct spk_synth *in_synth) +{ + u8 rv = ttyio_in(in_synth, 0); + + return (rv == 0xff) ? 0 : rv; +} + +static void spk_ttyio_flush_buffer(struct spk_synth *in_synth) +{ + struct tty_struct *tty = in_synth->dev; + + if (tty->ops->flush_buffer) + tty->ops->flush_buffer(tty); +} + +int spk_ttyio_synth_probe(struct spk_synth *synth) +{ + int rv = spk_ttyio_initialise_ldisc(synth); + + if (rv) + return rv; + + synth->alive = 1; + + return 0; +} +EXPORT_SYMBOL_GPL(spk_ttyio_synth_probe); + +void spk_ttyio_release(struct spk_synth *in_synth) +{ + struct tty_struct *tty = in_synth->dev; + + if (tty == NULL) + return; + + tty_lock(tty); + + if (tty->ops->close) + tty->ops->close(tty, NULL); + + tty_ldisc_flush(tty); + tty_unlock(tty); + tty_kclose(tty); + + in_synth->dev = NULL; +} +EXPORT_SYMBOL_GPL(spk_ttyio_release); + +const char *spk_ttyio_synth_immediate(struct spk_synth *in_synth, const char *buff) +{ + struct tty_struct *tty = in_synth->dev; + u_char ch; + + while ((ch = *buff)) { + if (ch == '\n') + ch = in_synth->procspeech; + if (tty_write_room(tty) < 1 || + !in_synth->io_ops->synth_out(in_synth, ch)) + return buff; + buff++; + } + return NULL; +} +EXPORT_SYMBOL_GPL(spk_ttyio_synth_immediate); -- cgit v1.2.3