// SPDX-License-Identifier: GPL-2.0+
/*
 * originally written by: Kirk Reiser <kirk@braille.uwo.ca>
 * this version considerably modified by David Borowski, david575@rogers.com
 *
 * Copyright (C) 1998-99  Kirk Reiser.
 * Copyright (C) 2003 David Borowski.
 *
 * specifically written as a driver for the speakup screenreview
 * s not a general device driver.
 */
#include <linux/unistd.h>
#include <linux/proc_fs.h>
#include <linux/jiffies.h>
#include <linux/spinlock.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/kthread.h>
#include "speakup.h"
#include "spk_priv.h"

#define DRV_VERSION "2.20"
#define SYNTH_CLEAR 0x03
#define PROCSPEECH 0x0b
static int xoff;

static inline int synth_full(void)
{
        return xoff;
}

static void do_catch_up(struct spk_synth *synth);
static void synth_flush(struct spk_synth *synth);
static void read_buff_add(u_char c);
static unsigned char get_index(struct spk_synth *synth);

static int in_escape;
static int is_flushing;

static DEFINE_SPINLOCK(flush_lock);
static DECLARE_WAIT_QUEUE_HEAD(flush);

enum default_vars_id {
        CAPS_START_ID = 0, CAPS_STOP_ID,
        RATE_ID, PITCH_ID, INFLECTION_ID,
        VOL_ID, PUNCT_ID, VOICE_ID,
        DIRECT_ID, V_LAST_VAR_ID,
        NB_ID,
};

static struct var_t vars[NB_ID] = {
        [CAPS_START_ID] = { CAPS_START, .u.s = {"[:dv ap 160] " } },
        [CAPS_STOP_ID] = { CAPS_STOP, .u.s = {"[:dv ap 100 ] " } },
        [RATE_ID] = { RATE, .u.n = {"[:ra %d] ", 180, 75, 650, 0, 0, NULL } },
        [PITCH_ID] = { PITCH, .u.n = {"[:dv ap %d] ", 122, 50, 350, 0, 0, NULL } },
        [INFLECTION_ID] = { INFLECTION, .u.n = {"[:dv pr %d] ", 100, 0, 10000, 0, 0, NULL } },
        [VOL_ID] = { VOL, .u.n = {"[:dv g5 %d] ", 86, 60, 86, 0, 0, NULL } },
        [PUNCT_ID] = { PUNCT, .u.n = {"[:pu %c] ", 0, 0, 2, 0, 0, "nsa" } },
        [VOICE_ID] = { VOICE, .u.n = {"[:n%c] ", 0, 0, 9, 0, 0, "phfdburwkv" } },
        [DIRECT_ID] = { DIRECT, .u.n = {NULL, 0, 0, 1, 0, 0, NULL } },
        V_LAST_VAR
};

/*
 * These attributes will appear in /sys/accessibility/speakup/dectlk.
 */
static struct kobj_attribute caps_start_attribute =
        __ATTR(caps_start, 0644, spk_var_show, spk_var_store);
static struct kobj_attribute caps_stop_attribute =
        __ATTR(caps_stop, 0644, spk_var_show, spk_var_store);
static struct kobj_attribute pitch_attribute =
        __ATTR(pitch, 0644, spk_var_show, spk_var_store);
static struct kobj_attribute inflection_attribute =
        __ATTR(inflection, 0644, spk_var_show, spk_var_store);
static struct kobj_attribute punct_attribute =
        __ATTR(punct, 0644, spk_var_show, spk_var_store);
static struct kobj_attribute rate_attribute =
        __ATTR(rate, 0644, spk_var_show, spk_var_store);
static struct kobj_attribute voice_attribute =
        __ATTR(voice, 0644, spk_var_show, spk_var_store);
static struct kobj_attribute vol_attribute =
        __ATTR(vol, 0644, spk_var_show, spk_var_store);

static struct kobj_attribute delay_time_attribute =
        __ATTR(delay_time, 0644, spk_var_show, spk_var_store);
static struct kobj_attribute direct_attribute =
        __ATTR(direct, 0644, spk_var_show, spk_var_store);
static struct kobj_attribute full_time_attribute =
        __ATTR(full_time, 0644, spk_var_show, spk_var_store);
static struct kobj_attribute flush_time_attribute =
        __ATTR(flush_time, 0644, spk_var_show, spk_var_store);
static struct kobj_attribute jiffy_delta_attribute =
        __ATTR(jiffy_delta, 0644, spk_var_show, spk_var_store);
static struct kobj_attribute trigger_time_attribute =
        __ATTR(trigger_time, 0644, spk_var_show, spk_var_store);

/*
 * Create a group of attributes so that we can create and destroy them all
 * at once.
 */
static struct attribute *synth_attrs[] = {
        &caps_start_attribute.attr,
        &caps_stop_attribute.attr,
        &pitch_attribute.attr,
        &inflection_attribute.attr,
        &punct_attribute.attr,
        &rate_attribute.attr,
        &voice_attribute.attr,
        &vol_attribute.attr,
        &delay_time_attribute.attr,
        &direct_attribute.attr,
        &full_time_attribute.attr,
        &flush_time_attribute.attr,
        &jiffy_delta_attribute.attr,
        &trigger_time_attribute.attr,
        NULL,   /* need to NULL terminate the list of attributes */
};

static int ap_defaults[] = {122, 89, 155, 110, 208, 240, 200, 106, 306};
static int g5_defaults[] = {86, 81, 86, 84, 81, 80, 83, 83, 73};

static struct spk_synth synth_dectlk = {
        .name = "dectlk",
        .version = DRV_VERSION,
        .long_name = "Dectalk Express",
        .init = "[:error sp :name paul :rate 180 :tsr off] ",
        .procspeech = PROCSPEECH,
        .clear = SYNTH_CLEAR,
        .delay = 500,
        .trigger = 50,
        .jiffies = 50,
        .full = 40000,
        .flush_time = 4000,
        .dev_name = SYNTH_DEFAULT_DEV,
        .startup = SYNTH_START,
        .checkval = SYNTH_CHECK,
        .vars = vars,
        .default_pitch = ap_defaults,
        .default_vol = g5_defaults,
        .io_ops = &spk_ttyio_ops,
        .probe = spk_ttyio_synth_probe,
        .release = spk_ttyio_release,
        .synth_immediate = spk_ttyio_synth_immediate,
        .catch_up = do_catch_up,
        .flush = synth_flush,
        .is_alive = spk_synth_is_alive_restart,
        .synth_adjust = NULL,
        .read_buff_add = read_buff_add,
        .get_index = get_index,
        .indexing = {
                .command = "[:in re %d ] ",
                .lowindex = 1,
                .highindex = 8,
                .currindex = 1,
        },
        .attributes = {
                .attrs = synth_attrs,
                .name = "dectlk",
        },
};

static int is_indnum(u_char *ch)
{
        if ((*ch >= '0') && (*ch <= '9')) {
                *ch = *ch - '0';
                return 1;
        }
        return 0;
}

static u_char lastind;

static unsigned char get_index(struct spk_synth *synth)
{
        u_char rv;

        rv = lastind;
        lastind = 0;
        return rv;
}

static void read_buff_add(u_char c)
{
        static int ind = -1;

        if (c == 0x01) {
                unsigned long flags;

                spin_lock_irqsave(&flush_lock, flags);
                is_flushing = 0;
                wake_up_interruptible(&flush);
                spin_unlock_irqrestore(&flush_lock, flags);
        } else if (c == 0x13) {
                xoff = 1;
        } else if (c == 0x11) {
                xoff = 0;
        } else if (is_indnum(&c)) {
                if (ind == -1)
                        ind = c;
                else
                        ind = ind * 10 + c;
        } else if ((c > 31) && (c < 127)) {
                if (ind != -1)
                        lastind = (u_char)ind;
                ind = -1;
        }
}

static void do_catch_up(struct spk_synth *synth)
{
        int synth_full_val = 0;
        static u_char ch;
        static u_char last = '\0';
        unsigned long flags;
        unsigned long jiff_max;
        unsigned long timeout;
        DEFINE_WAIT(wait);
        struct var_t *jiffy_delta;
        struct var_t *delay_time;
        struct var_t *flush_time;
        int jiffy_delta_val;
        int delay_time_val;
        int timeout_val;

        jiffy_delta = spk_get_var(JIFFY);
        delay_time = spk_get_var(DELAY);
        flush_time = spk_get_var(FLUSH);
        spin_lock_irqsave(&speakup_info.spinlock, flags);
        jiffy_delta_val = jiffy_delta->u.n.value;
        timeout_val = flush_time->u.n.value;
        spin_unlock_irqrestore(&speakup_info.spinlock, flags);
        timeout = msecs_to_jiffies(timeout_val);
        jiff_max = jiffies + jiffy_delta_val;

        while (!kthread_should_stop()) {
                /* if no ctl-a in 4, send data anyway */
                spin_lock_irqsave(&flush_lock, flags);
                while (is_flushing && timeout) {
                        prepare_to_wait(&flush, &wait, TASK_INTERRUPTIBLE);
                        spin_unlock_irqrestore(&flush_lock, flags);
                        timeout = schedule_timeout(timeout);
                        spin_lock_irqsave(&flush_lock, flags);
                }
                finish_wait(&flush, &wait);
                is_flushing = 0;
                spin_unlock_irqrestore(&flush_lock, flags);

                spin_lock_irqsave(&speakup_info.spinlock, flags);
                if (speakup_info.flushing) {
                        speakup_info.flushing = 0;
                        spin_unlock_irqrestore(&speakup_info.spinlock, flags);
                        synth->flush(synth);
                        continue;
                }
                synth_buffer_skip_nonlatin1();
                if (synth_buffer_empty()) {
                        spin_unlock_irqrestore(&speakup_info.spinlock, flags);
                        break;
                }
                ch = synth_buffer_peek();
                set_current_state(TASK_INTERRUPTIBLE);
                delay_time_val = delay_time->u.n.value;
                synth_full_val = synth_full();
                spin_unlock_irqrestore(&speakup_info.spinlock, flags);
                if (ch == '\n')
                        ch = 0x0D;
                if (synth_full_val || !synth->io_ops->synth_out(synth, ch)) {
                        schedule_timeout(msecs_to_jiffies(delay_time_val));
                        continue;
                }
                set_current_state(TASK_RUNNING);
                spin_lock_irqsave(&speakup_info.spinlock, flags);
                synth_buffer_getc();
                spin_unlock_irqrestore(&speakup_info.spinlock, flags);
                if (ch == '[') {
                        in_escape = 1;
                } else if (ch == ']') {
                        in_escape = 0;
                } else if (ch <= SPACE) {
                        if (!in_escape && strchr(",.!?;:", last))
                                synth->io_ops->synth_out(synth, PROCSPEECH);
                        if (time_after_eq(jiffies, jiff_max)) {
                                if (!in_escape)
                                        synth->io_ops->synth_out(synth,
                                                                 PROCSPEECH);
                                spin_lock_irqsave(&speakup_info.spinlock,
                                                  flags);
                                jiffy_delta_val = jiffy_delta->u.n.value;
                                delay_time_val = delay_time->u.n.value;
                                spin_unlock_irqrestore(&speakup_info.spinlock,
                                                       flags);
                                schedule_timeout(msecs_to_jiffies
                                                 (delay_time_val));
                                jiff_max = jiffies + jiffy_delta_val;
                        }
                }
                last = ch;
        }
        if (!in_escape)
                synth->io_ops->synth_out(synth, PROCSPEECH);
}

static void synth_flush(struct spk_synth *synth)
{
        if (in_escape)
                /* if in command output ']' so we don't get an error */
                synth->io_ops->synth_out(synth, ']');
        in_escape = 0;
        is_flushing = 1;
        synth->io_ops->flush_buffer(synth);
        synth->io_ops->synth_out(synth, SYNTH_CLEAR);
}

module_param_named(ser, synth_dectlk.ser, int, 0444);
module_param_named(dev, synth_dectlk.dev_name, charp, 0444);
module_param_named(start, synth_dectlk.startup, short, 0444);
module_param_named(rate, vars[RATE_ID].u.n.default_val, int, 0444);
module_param_named(pitch, vars[PITCH_ID].u.n.default_val, int, 0444);
module_param_named(inflection, vars[INFLECTION_ID].u.n.default_val, int, 0444);
module_param_named(vol, vars[VOL_ID].u.n.default_val, int, 0444);
module_param_named(punct, vars[PUNCT_ID].u.n.default_val, int, 0444);
module_param_named(voice, vars[VOICE_ID].u.n.default_val, int, 0444);
module_param_named(direct, vars[DIRECT_ID].u.n.default_val, int, 0444);



MODULE_PARM_DESC(ser, "Set the serial port for the synthesizer (0-based).");
MODULE_PARM_DESC(dev, "Set the device e.g. ttyUSB0, for the synthesizer.");
MODULE_PARM_DESC(start, "Start the synthesizer once it is loaded.");
MODULE_PARM_DESC(rate, "Set the rate variable on load.");
MODULE_PARM_DESC(pitch, "Set the pitch variable on load.");
MODULE_PARM_DESC(inflection, "Set the inflection variable on load.");
MODULE_PARM_DESC(vol, "Set the vol variable on load.");
MODULE_PARM_DESC(punct, "Set the punct variable on load.");
MODULE_PARM_DESC(voice, "Set the voice variable on load.");
MODULE_PARM_DESC(direct, "Set the direct variable on load.");


module_spk_synth(synth_dectlk);

MODULE_AUTHOR("Kirk Reiser <kirk@braille.uwo.ca>");
MODULE_AUTHOR("David Borowski");
MODULE_DESCRIPTION("Speakup support for DECtalk Express synthesizers");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);