1/*
2 * sound/oss/uart6850.c
3 *
4 *
5 * Copyright (C) by Hannu Savolainen 1993-1997
6 *
7 * OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
8 * Version 2 (June 1991). See the "COPYING" file distributed with this software
9 * for more info.
10 * Extended by Alan Cox for Red Hat Software. Now a loadable MIDI driver.
11 * 28/4/97 - (C) Copyright Alan Cox. Released under the GPL version 2.
12 *
13 * Alan Cox:		Updated for new modular code. Removed snd_* irq handling. Now
14 *			uses native linux resources
15 * Christoph Hellwig:	Adapted to module_init/module_exit
16 * Jeff Garzik:		Made it work again, in theory
17 *			FIXME: If the request_irq() succeeds, the probe succeeds. Ug.
18 *
19 *	Status: Testing required (no shit -jgarzik)
20 *
21 *
22 */
23
24#include <linux/init.h>
25#include <linux/interrupt.h>
26#include <linux/module.h>
27#include <linux/spinlock.h>
28/* Mon Nov 22 22:38:35 MET 1993 marco@driq.home.usn.nl:
29 *      added 6850 support, used with COVOX SoundMaster II and custom cards.
30 */
31
32#include "sound_config.h"
33
34static int uart6850_base = 0x330;
35
36static int *uart6850_osp;
37
38#define	DATAPORT   (uart6850_base)
39#define	COMDPORT   (uart6850_base+1)
40#define	STATPORT   (uart6850_base+1)
41
42static int uart6850_status(void)
43{
44	return inb(STATPORT);
45}
46
47#define input_avail()		(uart6850_status()&INPUT_AVAIL)
48#define output_ready()		(uart6850_status()&OUTPUT_READY)
49
50static void uart6850_cmd(unsigned char cmd)
51{
52	outb(cmd, COMDPORT);
53}
54
55static int uart6850_read(void)
56{
57	return inb(DATAPORT);
58}
59
60static void uart6850_write(unsigned char byte)
61{
62	outb(byte, DATAPORT);
63}
64
65#define	OUTPUT_READY	0x02	/* Mask for data ready Bit */
66#define	INPUT_AVAIL	0x01	/* Mask for Data Send Ready Bit */
67
68#define	UART_RESET	0x95
69#define	UART_MODE_ON	0x03
70
71static int uart6850_opened;
72static int uart6850_irq;
73static int uart6850_detected;
74static int my_dev;
75static DEFINE_SPINLOCK(lock);
76
77static void (*midi_input_intr) (int dev, unsigned char data);
78static void poll_uart6850(unsigned long dummy);
79
80
81static DEFINE_TIMER(uart6850_timer, poll_uart6850, 0, 0);
82
83static void uart6850_input_loop(void)
84{
85	int count = 10;
86
87	while (count)
88	{
89		/*
90		 * Not timed out
91		 */
92		if (input_avail())
93		{
94			unsigned char c = uart6850_read();
95			count = 100;
96			if (uart6850_opened & OPEN_READ)
97				midi_input_intr(my_dev, c);
98		}
99		else
100		{
101			while (!input_avail() && count)
102				count--;
103		}
104	}
105}
106
107static irqreturn_t m6850intr(int irq, void *dev_id)
108{
109	if (input_avail())
110		uart6850_input_loop();
111	return IRQ_HANDLED;
112}
113
114/*
115 *	It looks like there is no input interrupts in the UART mode. Let's try
116 *	polling.
117 */
118
119static void poll_uart6850(unsigned long dummy)
120{
121	unsigned long flags;
122
123	if (!(uart6850_opened & OPEN_READ))
124		return;		/* Device has been closed */
125
126	spin_lock_irqsave(&lock,flags);
127	if (input_avail())
128		uart6850_input_loop();
129
130	uart6850_timer.expires = 1 + jiffies;
131	add_timer(&uart6850_timer);
132
133	/*
134	 *	Come back later
135	 */
136
137	spin_unlock_irqrestore(&lock,flags);
138}
139
140static int uart6850_open(int dev, int mode,
141	      void            (*input) (int dev, unsigned char data),
142	      void            (*output) (int dev)
143)
144{
145	if (uart6850_opened)
146	{
147/*		  printk("Midi6850: Midi busy\n");*/
148		  return -EBUSY;
149	}
150
151	uart6850_cmd(UART_RESET);
152	uart6850_input_loop();
153	midi_input_intr = input;
154	uart6850_opened = mode;
155	poll_uart6850(0);	/*
156				 * Enable input polling
157				 */
158
159	return 0;
160}
161
162static void uart6850_close(int dev)
163{
164	uart6850_cmd(UART_MODE_ON);
165	del_timer(&uart6850_timer);
166	uart6850_opened = 0;
167}
168
169static int uart6850_out(int dev, unsigned char midi_byte)
170{
171	int timeout;
172	unsigned long flags;
173
174	/*
175	 * Test for input since pending input seems to block the output.
176	 */
177
178	spin_lock_irqsave(&lock,flags);
179
180	if (input_avail())
181		uart6850_input_loop();
182
183	spin_unlock_irqrestore(&lock,flags);
184
185	/*
186	 * Sometimes it takes about 13000 loops before the output becomes ready
187	 * (After reset). Normally it takes just about 10 loops.
188	 */
189
190	for (timeout = 30000; timeout > 0 && !output_ready(); timeout--);	/*
191										 * Wait
192										 */
193	if (!output_ready())
194	{
195		printk(KERN_WARNING "Midi6850: Timeout\n");
196		return 0;
197	}
198	uart6850_write(midi_byte);
199	return 1;
200}
201
202static inline int uart6850_command(int dev, unsigned char *midi_byte)
203{
204	return 1;
205}
206
207static inline int uart6850_start_read(int dev)
208{
209	return 0;
210}
211
212static inline int uart6850_end_read(int dev)
213{
214	return 0;
215}
216
217static inline void uart6850_kick(int dev)
218{
219}
220
221static inline int uart6850_buffer_status(int dev)
222{
223	return 0;		/*
224				 * No data in buffers
225				 */
226}
227
228#define MIDI_SYNTH_NAME	"6850 UART Midi"
229#define MIDI_SYNTH_CAPS	SYNTH_CAP_INPUT
230#include "midi_synth.h"
231
232static struct midi_operations uart6850_operations =
233{
234	.owner		= THIS_MODULE,
235	.info		= {"6850 UART", 0, 0, SNDCARD_UART6850},
236	.converter	= &std_midi_synth,
237	.in_info	= {0},
238	.open		= uart6850_open,
239	.close		= uart6850_close,
240	.outputc	= uart6850_out,
241	.start_read	= uart6850_start_read,
242	.end_read	= uart6850_end_read,
243	.kick		= uart6850_kick,
244	.command	= uart6850_command,
245	.buffer_status	= uart6850_buffer_status
246};
247
248
249static void __init attach_uart6850(struct address_info *hw_config)
250{
251	int ok, timeout;
252	unsigned long   flags;
253
254	if (!uart6850_detected)
255		return;
256
257	if ((my_dev = sound_alloc_mididev()) == -1)
258	{
259		printk(KERN_INFO "uart6850: Too many midi devices detected\n");
260		return;
261	}
262	uart6850_base = hw_config->io_base;
263	uart6850_osp = hw_config->osp;
264	uart6850_irq = hw_config->irq;
265
266	spin_lock_irqsave(&lock,flags);
267
268	for (timeout = 30000; timeout > 0 && !output_ready(); timeout--);	/*
269										 * Wait
270										 */
271	uart6850_cmd(UART_MODE_ON);
272	ok = 1;
273	spin_unlock_irqrestore(&lock,flags);
274
275	conf_printf("6850 Midi Interface", hw_config);
276
277	std_midi_synth.midi_dev = my_dev;
278	hw_config->slots[4] = my_dev;
279	midi_devs[my_dev] = &uart6850_operations;
280	sequencer_init();
281}
282
283static inline int reset_uart6850(void)
284{
285	uart6850_read();
286	return 1;		/*
287				 * OK
288				 */
289}
290
291static int __init probe_uart6850(struct address_info *hw_config)
292{
293	int ok;
294
295	uart6850_osp = hw_config->osp;
296	uart6850_base = hw_config->io_base;
297	uart6850_irq = hw_config->irq;
298
299	if (request_irq(uart6850_irq, m6850intr, 0, "MIDI6850", NULL) < 0)
300		return 0;
301
302	ok = reset_uart6850();
303	uart6850_detected = ok;
304	return ok;
305}
306
307static void __exit unload_uart6850(struct address_info *hw_config)
308{
309	free_irq(hw_config->irq, NULL);
310	sound_unload_mididev(hw_config->slots[4]);
311}
312
313static struct address_info cfg_mpu;
314
315static int __initdata io = -1;
316static int __initdata irq = -1;
317
318module_param(io, int, 0);
319module_param(irq, int, 0);
320
321static int __init init_uart6850(void)
322{
323	cfg_mpu.io_base = io;
324	cfg_mpu.irq = irq;
325
326	if (cfg_mpu.io_base == -1 || cfg_mpu.irq == -1) {
327		printk(KERN_INFO "uart6850: irq and io must be set.\n");
328		return -EINVAL;
329	}
330
331	if (probe_uart6850(&cfg_mpu))
332		return -ENODEV;
333	attach_uart6850(&cfg_mpu);
334
335	return 0;
336}
337
338static void __exit cleanup_uart6850(void)
339{
340	unload_uart6850(&cfg_mpu);
341}
342
343module_init(init_uart6850);
344module_exit(cleanup_uart6850);
345
346#ifndef MODULE
347static int __init setup_uart6850(char *str)
348{
349	/* io, irq */
350	int ints[3];
351
352	str = get_options(str, ARRAY_SIZE(ints), ints);
353
354	io = ints[1];
355	irq = ints[2];
356
357	return 1;
358}
359__setup("uart6850=", setup_uart6850);
360#endif
361MODULE_LICENSE("GPL");
362