// SPDX-License-Identifier: GPL-2.0+
/*
 * This is the DECtalk PC speakup driver
 *
 * Some constants from DEC's DOS driver:
 *      Copyright (c) by Digital Equipment Corp.
 *
 * 386BSD DECtalk PC driver:
 *      Copyright (c) 1996 Brian Buhrow <buhrow@lothlorien.nfbcal.org>
 *
 * Linux DECtalk PC driver:
 *      Copyright (c) 1997 Nicolas Pitre <nico@cam.org>
 *
 * speakup DECtalk PC Internal driver:
 *      Copyright (c) 2003 David Borowski <david575@golden.net>
 *
 * All rights reserved.
 */
#include <linux/jiffies.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/kthread.h>

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

#define	MODULE_init		0x0dec	/* module in boot code */
#define	MODULE_self_test	0x8800	/* module in self-test */
#define	MODULE_reset		0xffff	/* reinit the whole module */

#define	MODE_mask		0xf000	/* mode bits in high nibble */
#define	MODE_null		0x0000
#define	MODE_test		0x2000	/* in testing mode */
#define	MODE_status		0x8000
#define	STAT_int		0x0001	/* running in interrupt mode */
#define	STAT_tr_char		0x0002	/* character data to transmit */
#define	STAT_rr_char		0x0004	/* ready to receive char data */
#define	STAT_cmd_ready		0x0008	/* ready to accept commands */
#define	STAT_dma_ready		0x0010	/* dma command ready */
#define	STAT_digitized		0x0020	/* spc in digitized mode */
#define	STAT_new_index		0x0040	/* new last index ready */
#define	STAT_new_status		0x0080	/* new status posted */
#define	STAT_dma_state		0x0100	/* dma state toggle */
#define	STAT_index_valid	0x0200	/* indexs are valid */
#define	STAT_flushing		0x0400	/* flush in progress */
#define	STAT_self_test		0x0800	/* module in self test */
#define	MODE_ready		0xc000	/* module ready for next phase */
#define	READY_boot		0x0000
#define	READY_kernel		0x0001
#define	MODE_error		0xf000

#define	CMD_mask		0xf000	/* mask for command nibble */
#define	CMD_null		0x0000	/* post status */
#define	CMD_control		0x1000	/* hard control command */
#define	CTRL_mask		0x0F00	/* mask off control nibble */
#define	CTRL_data		0x00FF	/* mask to get data byte */
#define	CTRL_null		0x0000	/* null control */
#define	CTRL_vol_up		0x0100	/* increase volume */
#define	CTRL_vol_down		0x0200	/* decrease volume */
#define	CTRL_vol_set		0x0300	/* set volume */
#define	CTRL_pause		0x0400	/* pause spc */
#define	CTRL_resume		0x0500	/* resume spc clock */
#define	CTRL_resume_spc		0x0001	/* resume spc soft pause */
#define	CTRL_flush		0x0600	/* flush all buffers */
#define	CTRL_int_enable		0x0700	/* enable status change ints */
#define	CTRL_buff_free		0x0800	/* buffer remain count */
#define	CTRL_buff_used		0x0900	/* buffer in use */
#define	CTRL_speech		0x0a00	/* immediate speech change */
#define	CTRL_SP_voice		0x0001	/* voice change */
#define	CTRL_SP_rate		0x0002	/* rate change */
#define	CTRL_SP_comma		0x0003	/* comma pause change */
#define	CTRL_SP_period		0x0004	/* period pause change */
#define	CTRL_SP_rate_delta	0x0005	/* delta rate change */
#define	CTRL_SP_get_param	0x0006	/* return the desired parameter */
#define	CTRL_last_index		0x0b00	/* get last index spoken */
#define	CTRL_io_priority	0x0c00	/* change i/o priority */
#define	CTRL_free_mem		0x0d00	/* get free paragraphs on module */
#define	CTRL_get_lang		0x0e00	/* return bitmask of loaded languages */
#define	CMD_test		0x2000	/* self-test request */
#define	TEST_mask		0x0F00	/* isolate test field */
#define	TEST_null		0x0000	/* no test requested */
#define	TEST_isa_int		0x0100	/* assert isa irq */
#define	TEST_echo		0x0200	/* make data in == data out */
#define	TEST_seg		0x0300	/* set peek/poke segment */
#define	TEST_off		0x0400	/* set peek/poke offset */
#define	TEST_peek		0x0500	/* data out == *peek */
#define	TEST_poke		0x0600	/* *peek == data in */
#define	TEST_sub_code		0x00FF	/* user defined test sub codes */
#define	CMD_id			0x3000	/* return software id */
#define	ID_null			0x0000	/* null id */
#define	ID_kernel		0x0100	/* kernel code executing */
#define	ID_boot			0x0200	/* boot code executing */
#define	CMD_dma			0x4000	/* force a dma start */
#define	CMD_reset		0x5000	/* reset module status */
#define	CMD_sync		0x6000	/* kernel sync command */
#define	CMD_char_in		0x7000	/* single character send */
#define	CMD_char_out		0x8000	/* single character get */
#define	CHAR_count_1		0x0100	/* one char in cmd_low */
#define	CHAR_count_2		0x0200	/* the second in data_low */
#define	CHAR_count_3		0x0300	/* the third in data_high */
#define	CMD_spc_mode		0x9000	/* change spc mode */
#define	CMD_spc_to_text		0x0100	/* set to text mode */
#define	CMD_spc_to_digit	0x0200	/* set to digital mode */
#define	CMD_spc_rate		0x0400	/* change spc data rate */
#define	CMD_error		0xf000	/* severe error */

enum {	PRIMARY_DIC	= 0, USER_DIC, COMMAND_DIC, ABBREV_DIC };

#define	DMA_single_in		0x01
#define	DMA_single_out		0x02
#define	DMA_buff_in		0x03
#define	DMA_buff_out		0x04
#define	DMA_control		0x05
#define	DT_MEM_ALLOC		0x03
#define	DT_SET_DIC		0x04
#define	DT_START_TASK		0x05
#define	DT_LOAD_MEM		0x06
#define	DT_READ_MEM		0x07
#define	DT_DIGITAL_IN		0x08
#define	DMA_sync		0x06
#define	DMA_sync_char		0x07

#define DRV_VERSION "2.12"
#define PROCSPEECH 0x0b
#define SYNTH_IO_EXTENT 8

static int synth_probe(struct spk_synth *synth);
static void dtpc_release(void);
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_portlist[] = { 0x340, 0x350, 0x240, 0x250, 0 };
static int in_escape, is_flushing;
static int dt_stat, dma_state;

static struct var_t vars[] = {
	{ CAPS_START, .u.s = {"[:dv ap 200]" } },
	{ CAPS_STOP, .u.s = {"[:dv ap 100]" } },
	{ RATE, .u.n = {"[:ra %d]", 9, 0, 18, 150, 25, NULL } },
	{ PITCH, .u.n = {"[:dv ap %d]", 80, 0, 100, 20, 0, NULL } },
	{ VOL, .u.n = {"[:vo se %d]", 5, 0, 9, 5, 10, NULL } },
	{ PUNCT, .u.n = {"[:pu %c]", 0, 0, 2, 0, 0, "nsa" } },
	{ VOICE, .u.n = {"[:n%c]", 0, 0, 9, 0, 0, "phfdburwkv" } },
	{ DIRECT, .u.n = {NULL, 0, 0, 1, 0, 0, NULL } },
	V_LAST_VAR
};

/*
 * These attributes will appear in /sys/accessibility/speakup/decpc.
 */
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 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 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,
	&punct_attribute.attr,
	&rate_attribute.attr,
	&voice_attribute.attr,
	&vol_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_dec_pc = {
	.name = "decpc",
	.version = DRV_VERSION,
	.long_name = "Dectalk PC",
	.init = "[:pe -380]",
	.procspeech = PROCSPEECH,
	.delay = 500,
	.trigger = 50,
	.jiffies = 50,
	.full = 1000,
	.flags = SF_DEC,
	.startup = SYNTH_START,
	.checkval = SYNTH_CHECK,
	.vars = vars,
	.io_ops = &spk_serial_io_ops,
	.probe = synth_probe,
	.release = dtpc_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 = "decpc",
	},
};

static int dt_getstatus(void)
{
	dt_stat = inb_p(speakup_info.port_tts) |
		 (inb_p(speakup_info.port_tts + 1) << 8);
	return dt_stat;
}

static void dt_sendcmd(u_int cmd)
{
	outb_p(cmd & 0xFF, speakup_info.port_tts);
	outb_p((cmd >> 8) & 0xFF, speakup_info.port_tts + 1);
}

static int dt_waitbit(int bit)
{
	int timeout = 100;

	while (--timeout > 0) {
		if ((dt_getstatus() & bit) == bit)
			return 1;
		udelay(50);
	}
	return 0;
}

static int dt_wait_dma(void)
{
	int timeout = 100, state = dma_state;

	if (!dt_waitbit(STAT_dma_ready))
		return 0;
	while (--timeout > 0) {
		if ((dt_getstatus() & STAT_dma_state) == state)
			return 1;
		udelay(50);
	}
	dma_state = dt_getstatus() & STAT_dma_state;
	return 1;
}

static int dt_ctrl(u_int cmd)
{
	int timeout = 10;

	if (!dt_waitbit(STAT_cmd_ready))
		return -1;
	outb_p(0, speakup_info.port_tts + 2);
	outb_p(0, speakup_info.port_tts + 3);
	dt_getstatus();
	dt_sendcmd(CMD_control | cmd);
	outb_p(0, speakup_info.port_tts + 6);
	while (dt_getstatus() & STAT_cmd_ready) {
		udelay(20);
		if (--timeout == 0)
			break;
	}
	dt_sendcmd(CMD_null);
	return 0;
}

static void synth_flush(struct spk_synth *synth)
{
	int timeout = 10;

	if (is_flushing)
		return;
	is_flushing = 4;
	in_escape = 0;
	while (dt_ctrl(CTRL_flush)) {
		if (--timeout == 0)
			break;
		udelay(50);
	}
	for (timeout = 0; timeout < 10; timeout++) {
		if (dt_waitbit(STAT_dma_ready))
			break;
		udelay(50);
	}
	outb_p(DMA_sync, speakup_info.port_tts + 4);
	outb_p(0, speakup_info.port_tts + 4);
	udelay(100);
	for (timeout = 0; timeout < 10; timeout++) {
		if (!(dt_getstatus() & STAT_flushing))
			break;
		udelay(50);
	}
	dma_state = dt_getstatus() & STAT_dma_state;
	dma_state ^= STAT_dma_state;
	is_flushing = 0;
}

static int dt_sendchar(char ch)
{
	if (!dt_wait_dma())
		return -1;
	if (!(dt_stat & STAT_rr_char))
		return -2;
	outb_p(DMA_single_in, speakup_info.port_tts + 4);
	outb_p(ch, speakup_info.port_tts + 4);
	dma_state ^= STAT_dma_state;
	return 0;
}

static int testkernel(void)
{
	int status = 0;

	if (dt_getstatus() == 0xffff) {
		status = -1;
		goto oops;
	}
	dt_sendcmd(CMD_sync);
	if (!dt_waitbit(STAT_cmd_ready))
		status = -2;
	else if (dt_stat & 0x8000)
		return 0;
	else if (dt_stat == 0x0dec)
		pr_warn("dec_pc at 0x%x, software not loaded\n",
			speakup_info.port_tts);
	status = -3;
oops:	synth_release_region(speakup_info.port_tts, SYNTH_IO_EXTENT);
	speakup_info.port_tts = 0;
	return status;
}

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

	jiffy_delta = spk_get_var(JIFFY);
	delay_time = spk_get_var(DELAY);
	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;
		}
		ch = synth_buffer_peek();
		set_current_state(TASK_INTERRUPTIBLE);
		delay_time_val = delay_time->u.n.value;
		spin_unlock_irqrestore(&speakup_info.spinlock, flags);
		if (ch == '\n')
			ch = 0x0D;
		if (dt_sendchar(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))
				dt_sendchar(PROCSPEECH);
			if (time_after_eq(jiffies, jiff_max)) {
				if (!in_escape)
					dt_sendchar(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;
		ch = 0;
	}
	if (!in_escape)
		dt_sendchar(PROCSPEECH);
}

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

	while ((ch = *buf)) {
		if (ch == '\n')
			ch = PROCSPEECH;
		if (dt_sendchar(ch))
			return buf;
		buf++;
	}
	return NULL;
}

static int synth_probe(struct spk_synth *synth)
{
	int i = 0, failed = 0;

	pr_info("Probing for %s.\n", synth->long_name);
	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;
		}
		speakup_info.port_tts = synth_portlist[i];
		failed = testkernel();
		if (failed == 0)
			break;
	}
	if (failed) {
		pr_info("%s: not found\n", synth->long_name);
		return -ENODEV;
	}
	pr_info("%s: %03x-%03x, Driver Version %s,\n", synth->long_name,
		speakup_info.port_tts, speakup_info.port_tts + 7,
		synth->version);
	synth->alive = 1;
	return 0;
}

static void dtpc_release(void)
{
	spk_stop_serial_interrupt();
	if (speakup_info.port_tts)
		synth_release_region(speakup_info.port_tts, SYNTH_IO_EXTENT);
	speakup_info.port_tts = 0;
}

module_param_named(start, synth_dec_pc.startup, short, 0444);

MODULE_PARM_DESC(start, "Start the synthesizer once it is loaded.");

module_spk_synth(synth_dec_pc);

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