// SPDX-License-Identifier: GPL-2.0+
/*
 * written by David Borowski
 *
 * Copyright (C) 2003 David Borowski.
 *
 * specificly written as a driver for the speakup screenreview
 * package it's not a general device driver.
 * This driver is for the Keynote Gold internal synthesizer.
 */
#include <linux/jiffies.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/kthread.h>
#include <linux/serial_reg.h>

#include "spk_priv.h"
#include "speakup.h"

#define DRV_VERSION "2.10"
#define SYNTH_IO_EXTENT	0x04
#define SWAIT udelay(70)
#define PROCSPEECH 0x1f
#define SYNTH_CLEAR 0x03

static int synth_probe(struct spk_synth *synth);
static void keynote_release(struct spk_synth *synth);
static const char *synth_immediate(struct spk_synth *synth, const char *buf);
static void do_catch_up(struct spk_synth *synth);
static void synth_flush(struct spk_synth *synth);

static int synth_port;
static int port_forced;
static unsigned int synth_portlist[] = { 0x2a8, 0 };

static struct var_t vars[] = {
	{ CAPS_START, .u.s = {"[f130]" } },
	{ CAPS_STOP, .u.s = {"[f90]" } },
	{ RATE, .u.n = {"\04%c ", 8, 0, 10, 81, -8, NULL } },
	{ PITCH, .u.n = {"[f%d]", 5, 0, 9, 40, 10, NULL } },
	{ DIRECT, .u.n = {NULL, 0, 0, 1, 0, 0, NULL } },
	V_LAST_VAR
};

/*
 * These attributes will appear in /sys/accessibility/speakup/keypc.
 */
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 rate_attribute =
	__ATTR(rate, 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 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,
	&rate_attribute.attr,
	&delay_time_attribute.attr,
	&direct_attribute.attr,
	&full_time_attribute.attr,
	&jiffy_delta_attribute.attr,
	&trigger_time_attribute.attr,
	NULL,	/* need to NULL terminate the list of attributes */
};

static struct spk_synth synth_keypc = {
	.name = "keypc",
	.version = DRV_VERSION,
	.long_name = "Keynote PC",
	.init = "[t][n7,1][n8,0]",
	.procspeech = PROCSPEECH,
	.clear = SYNTH_CLEAR,
	.delay = 500,
	.trigger = 50,
	.jiffies = 50,
	.full = 1000,
	.startup = SYNTH_START,
	.checkval = SYNTH_CHECK,
	.vars = vars,
	.io_ops = &spk_serial_io_ops,
	.probe = synth_probe,
	.release = keynote_release,
	.synth_immediate = synth_immediate,
	.catch_up = do_catch_up,
	.flush = synth_flush,
	.is_alive = spk_synth_is_alive_nop,
	.synth_adjust = NULL,
	.read_buff_add = NULL,
	.get_index = NULL,
	.indexing = {
		.command = NULL,
		.lowindex = 0,
		.highindex = 0,
		.currindex = 0,
	},
	.attributes = {
		.attrs = synth_attrs,
		.name = "keypc",
	},
};

static inline bool synth_writable(void)
{
	return (inb_p(synth_port + UART_RX) & 0x10) != 0;
}

static inline bool synth_full(void)
{
	return (inb_p(synth_port + UART_RX) & 0x80) == 0;
}

static char *oops(void)
{
	int s1, s2, s3, s4;

	s1 = inb_p(synth_port);
	s2 = inb_p(synth_port + 1);
	s3 = inb_p(synth_port + 2);
	s4 = inb_p(synth_port + 3);
	pr_warn("synth timeout %d %d %d %d\n", s1, s2, s3, s4);
	return NULL;
}

static const char *synth_immediate(struct spk_synth *synth, const char *buf)
{
	u_char ch;
	int timeout;

	while ((ch = *buf)) {
		if (ch == '\n')
			ch = PROCSPEECH;
		if (synth_full())
			return buf;
		timeout = 1000;
		while (synth_writable())
			if (--timeout <= 0)
				return oops();
		outb_p(ch, synth_port);
		udelay(70);
		buf++;
	}
	return NULL;
}

static void do_catch_up(struct spk_synth *synth)
{
	u_char ch;
	int timeout;
	unsigned long flags;
	unsigned long jiff_max;
	struct var_t *jiffy_delta;
	struct var_t *delay_time;
	struct var_t *full_time;
	int delay_time_val;
	int full_time_val;
	int jiffy_delta_val;

	jiffy_delta = spk_get_var(JIFFY);
	delay_time = spk_get_var(DELAY);
	full_time = spk_get_var(FULL);
	spin_lock_irqsave(&speakup_info.spinlock, flags);
	jiffy_delta_val = jiffy_delta->u.n.value;
	spin_unlock_irqrestore(&speakup_info.spinlock, flags);

	jiff_max = jiffies + jiffy_delta_val;
	while (!kthread_should_stop()) {
		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;
		}
		set_current_state(TASK_INTERRUPTIBLE);
		full_time_val = full_time->u.n.value;
		spin_unlock_irqrestore(&speakup_info.spinlock, flags);
		if (synth_full()) {
			schedule_timeout(msecs_to_jiffies(full_time_val));
			continue;
		}
		set_current_state(TASK_RUNNING);
		timeout = 1000;
		while (synth_writable())
			if (--timeout <= 0)
				break;
		if (timeout <= 0) {
			oops();
			break;
		}
		spin_lock_irqsave(&speakup_info.spinlock, flags);
		ch = synth_buffer_getc();
		spin_unlock_irqrestore(&speakup_info.spinlock, flags);
		if (ch == '\n')
			ch = PROCSPEECH;
		outb_p(ch, synth_port);
		SWAIT;
		if (time_after_eq(jiffies, jiff_max) && (ch == SPACE)) {
			timeout = 1000;
			while (synth_writable())
				if (--timeout <= 0)
					break;
			if (timeout <= 0) {
				oops();
				break;
			}
			outb_p(PROCSPEECH, synth_port);
			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;
		}
	}
	timeout = 1000;
	while (synth_writable())
		if (--timeout <= 0)
			break;
	if (timeout <= 0)
		oops();
	else
		outb_p(PROCSPEECH, synth_port);
}

static void synth_flush(struct spk_synth *synth)
{
	outb_p(SYNTH_CLEAR, synth_port);
}

static int synth_probe(struct spk_synth *synth)
{
	unsigned int port_val = 0;
	int i;

	pr_info("Probing for %s.\n", synth->long_name);
	if (port_forced) {
		synth_port = port_forced;
		pr_info("probe forced to %x by kernel command line\n",
			synth_port);
		if (synth_request_region(synth_port - 1, SYNTH_IO_EXTENT)) {
			pr_warn("sorry, port already reserved\n");
			return -EBUSY;
		}
		port_val = inb(synth_port);
	} else {
		for (i = 0; synth_portlist[i]; i++) {
			if (synth_request_region(synth_portlist[i],
						 SYNTH_IO_EXTENT)) {
				pr_warn
				    ("request_region: failed with 0x%x, %d\n",
				     synth_portlist[i], SYNTH_IO_EXTENT);
				continue;
			}
			port_val = inb(synth_portlist[i]);
			if (port_val == 0x80) {
				synth_port = synth_portlist[i];
				break;
			}
		}
	}
	if (port_val != 0x80) {
		pr_info("%s: not found\n", synth->long_name);
		synth_release_region(synth_port, SYNTH_IO_EXTENT);
		synth_port = 0;
		return -ENODEV;
	}
	pr_info("%s: %03x-%03x, driver version %s,\n", synth->long_name,
		synth_port, synth_port + SYNTH_IO_EXTENT - 1,
		synth->version);
	synth->alive = 1;
	return 0;
}

static void keynote_release(struct spk_synth *synth)
{
	spk_stop_serial_interrupt();
	if (synth_port)
		synth_release_region(synth_port, SYNTH_IO_EXTENT);
	synth_port = 0;
}

module_param_hw_named(port, port_forced, int, ioport, 0444);
module_param_named(start, synth_keypc.startup, short, 0444);

MODULE_PARM_DESC(port, "Set the port for the synthesizer (override probing).");
MODULE_PARM_DESC(start, "Start the synthesizer once it is loaded.");

module_spk_synth(synth_keypc);

MODULE_AUTHOR("David Borowski");
MODULE_DESCRIPTION("Speakup support for Keynote Gold PC synthesizers");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);