aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/input/serio/sa1111ps2.c
blob: d31ece8f68e93df7ea82f61c949f48a64326d28c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
/*
 *  linux/drivers/input/serio/sa1111ps2.c
 *
 *  Copyright (C) 2002 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License.
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/serio.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

#include <asm/io.h>
#include <asm/system.h>

#include <asm/hardware/sa1111.h>

struct ps2if {
	struct serio		*io;
	struct sa1111_dev	*dev;
	void __iomem		*base;
	unsigned int		open;
	spinlock_t		lock;
	unsigned int		head;
	unsigned int		tail;
	unsigned char		buf[4];
};

/*
 * Read all bytes waiting in the PS2 port.  There should be
 * at the most one, but we loop for safety.  If there was a
 * framing error, we have to manually clear the status.
 */
static irqreturn_t ps2_rxint(int irq, void *dev_id)
{
	struct ps2if *ps2if = dev_id;
	unsigned int scancode, flag, status;

	status = sa1111_readl(ps2if->base + SA1111_PS2STAT);
	while (status & PS2STAT_RXF) {
		if (status & PS2STAT_STP)
			sa1111_writel(PS2STAT_STP, ps2if->base + SA1111_PS2STAT);

		flag = (status & PS2STAT_STP ? SERIO_FRAME : 0) |
		       (status & PS2STAT_RXP ? 0 : SERIO_PARITY);

		scancode = sa1111_readl(ps2if->base + SA1111_PS2DATA) & 0xff;

		if (hweight8(scancode) & 1)
			flag ^= SERIO_PARITY;

		serio_interrupt(ps2if->io, scancode, flag);

		status = sa1111_readl(ps2if->base + SA1111_PS2STAT);
        }

        return IRQ_HANDLED;
}

/*
 * Completion of ps2 write
 */
static irqreturn_t ps2_txint(int irq, void *dev_id)
{
	struct ps2if *ps2if = dev_id;
	unsigned int status;

	spin_lock(&ps2if->lock);
	status = sa1111_readl(ps2if->base + SA1111_PS2STAT);
	if (ps2if->head == ps2if->tail) {
		disable_irq(irq);
		/* done */
	} else if (status & PS2STAT_TXE) {
		sa1111_writel(ps2if->buf[ps2if->tail], ps2if->base + SA1111_PS2DATA);
		ps2if->tail = (ps2if->tail + 1) & (sizeof(ps2if->buf) - 1);
	}
	spin_unlock(&ps2if->lock);

	return IRQ_HANDLED;
}

/*
 * Write a byte to the PS2 port.  We have to wait for the
 * port to indicate that the transmitter is empty.
 */
static int ps2_write(struct serio *io, unsigned char val)
{
	struct ps2if *ps2if = io->port_data;
	unsigned long flags;
	unsigned int head;

	spin_lock_irqsave(&ps2if->lock, flags);

	/*
	 * If the TX register is empty, we can go straight out.
	 */
	if (sa1111_readl(ps2if->base + SA1111_PS2STAT) & PS2STAT_TXE) {
		sa1111_writel(val, ps2if->base + SA1111_PS2DATA);
	} else {
		if (ps2if->head == ps2if->tail)
			enable_irq(ps2if->dev->irq[1]);
		head = (ps2if->head + 1) & (sizeof(ps2if->buf) - 1);
		if (head != ps2if->tail) {
			ps2if->buf[ps2if->head] = val;
			ps2if->head = head;
		}
	}

	spin_unlock_irqrestore(&ps2if->lock, flags);
	return 0;
}

static int ps2_open(struct serio *io)
{
	struct ps2if *ps2if = io->port_data;
	int ret;

	sa1111_enable_device(ps2if->dev);

	ret = request_irq(ps2if->dev->irq[0], ps2_rxint, 0,
			  SA1111_DRIVER_NAME(ps2if->dev), ps2if);
	if (ret) {
		printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
			ps2if->dev->irq[0], ret);
		return ret;
	}

	ret = request_irq(ps2if->dev->irq[1], ps2_txint, 0,
			  SA1111_DRIVER_NAME(ps2if->dev), ps2if);
	if (ret) {
		printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
			ps2if->dev->irq[1], ret);
		free_irq(ps2if->dev->irq[0], ps2if);
		return ret;
	}

	ps2if->open = 1;

	enable_irq_wake(ps2if->dev->irq[0]);

	sa1111_writel(PS2CR_ENA, ps2if->base + SA1111_PS2CR);
	return 0;
}

static void ps2_close(struct serio *io)
{
	struct ps2if *ps2if = io->port_data;

	sa1111_writel(0, ps2if->base + SA1111_PS2CR);

	disable_irq_wake(ps2if->dev->irq[0]);

	ps2if->open = 0;

	free_irq(ps2if->dev->irq[1], ps2if);
	free_irq(ps2if->dev->irq[0], ps2if);

	sa1111_disable_device(ps2if->dev);
}

/*
 * Clear the input buffer.
 */
static void __devinit ps2_clear_input(struct ps2if *ps2if)
{
	int maxread = 100;

	while (maxread--) {
		if ((sa1111_readl(ps2if->base + SA1111_PS2DATA) & 0xff) == 0xff)
			break;
	}
}

static inline unsigned int
ps2_test_one(struct ps2if *ps2if, unsigned int mask)
{
	unsigned int val;

	sa1111_writel(PS2CR_ENA | mask, ps2if->base + SA1111_PS2CR);

	udelay(2);

	val = sa1111_readl(ps2if->base + SA1111_PS2STAT);
	return val & (PS2STAT_KBC | PS2STAT_KBD);
}

/*
 * Test the keyboard interface.  We basically check to make sure that
 * we can drive each line to the keyboard independently of each other.
 */
static int __init ps2_test(struct ps2if *ps2if)
{
	unsigned int stat;
	int ret = 0;

	stat = ps2_test_one(ps2if, PS2CR_FKC);
	if (stat != PS2STAT_KBD) {
		printk("PS/2 interface test failed[1]: %02x\n", stat);
		ret = -ENODEV;
	}

	stat = ps2_test_one(ps2if, 0);
	if (stat != (PS2STAT_KBC | PS2STAT_KBD)) {
		printk("PS/2 interface test failed[2]: %02x\n", stat);
		ret = -ENODEV;
	}

	stat = ps2_test_one(ps2if, PS2CR_FKD);
	if (stat != PS2STAT_KBC) {
		printk("PS/2 interface test failed[3]: %02x\n", stat);
		ret = -ENODEV;
	}

	sa1111_writel(0, ps2if->base + SA1111_PS2CR);

	return ret;
}

/*
 * Add one device to this driver.
 */
static int __devinit ps2_probe(struct sa1111_dev *dev)
{
	struct ps2if *ps2if;
	struct serio *serio;
	int ret;

	ps2if = kmalloc(sizeof(struct ps2if), GFP_KERNEL);
	serio = kmalloc(sizeof(struct serio), GFP_KERNEL);
	if (!ps2if || !serio) {
		ret = -ENOMEM;
		goto free;
	}

	memset(ps2if, 0, sizeof(struct ps2if));
	memset(serio, 0, sizeof(struct serio));

	serio->id.type		= SERIO_8042;
	serio->write		= ps2_write;
	serio->open		= ps2_open;
	serio->close		= ps2_close;
	strlcpy(serio->name, dev->dev.bus_id, sizeof(serio->name));
	strlcpy(serio->phys, dev->dev.bus_id, sizeof(serio->phys));
	serio->port_data	= ps2if;
	serio->dev.parent	= &dev->dev;
	ps2if->io		= serio;
	ps2if->dev		= dev;
	sa1111_set_drvdata(dev, ps2if);

	spin_lock_init(&ps2if->lock);

	/*
	 * Request the physical region for this PS2 port.
	 */
	if (!request_mem_region(dev->res.start,
				dev->res.end - dev->res.start + 1,
				SA1111_DRIVER_NAME(dev))) {
		ret = -EBUSY;
		goto free;
	}

	/*
	 * Our parent device has already mapped the region.
	 */
	ps2if->base = dev->mapbase;

	sa1111_enable_device(ps2if->dev);

	/* Incoming clock is 8MHz */
	sa1111_writel(0, ps2if->base + SA1111_PS2CLKDIV);
	sa1111_writel(127, ps2if->base + SA1111_PS2PRECNT);

	/*
	 * Flush any pending input.
	 */
	ps2_clear_input(ps2if);

	/*
	 * Test the keyboard interface.
	 */
	ret = ps2_test(ps2if);
	if (ret)
		goto out;

	/*
	 * Flush any pending input.
	 */
	ps2_clear_input(ps2if);

	sa1111_disable_device(ps2if->dev);
	serio_register_port(ps2if->io);
	return 0;

 out:
	sa1111_disable_device(ps2if->dev);
	release_mem_region(dev->res.start,
			   dev->res.end - dev->res.start + 1);
 free:
	sa1111_set_drvdata(dev, NULL);
	kfree(ps2if);
	kfree(serio);
	return ret;
}

/*
 * Remove one device from this driver.
 */
static int ps2_remove(struct sa1111_dev *dev)
{
	struct ps2if *ps2if = sa1111_get_drvdata(dev);

	serio_unregister_port(ps2if->io);
	release_mem_region(dev->res.start,
			   dev->res.end - dev->res.start + 1);
	sa1111_set_drvdata(dev, NULL);

	kfree(ps2if);

	return 0;
}

/*
 * Our device driver structure
 */
static struct sa1111_driver ps2_driver = {
	.drv = {
		.name	= "sa1111-ps2",
	},
	.devid		= SA1111_DEVID_PS2,
	.probe		= ps2_probe,
	.remove		= ps2_remove,
};

static int __init ps2_init(void)
{
	return sa1111_driver_register(&ps2_driver);
}

static void __exit ps2_exit(void)
{
	sa1111_driver_unregister(&ps2_driver);
}

module_init(ps2_init);
module_exit(ps2_exit);

MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
MODULE_DESCRIPTION("SA1111 PS2 controller driver");
MODULE_LICENSE("GPL");