1/*
2 *  linux/drivers/input/serio/sa1111ps2.c
3 *
4 *  Copyright (C) 2002 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License.
9 */
10#include <linux/module.h>
11#include <linux/init.h>
12#include <linux/input.h>
13#include <linux/serio.h>
14#include <linux/errno.h>
15#include <linux/interrupt.h>
16#include <linux/ioport.h>
17#include <linux/delay.h>
18#include <linux/device.h>
19#include <linux/slab.h>
20#include <linux/spinlock.h>
21
22#include <asm/io.h>
23#include <asm/system.h>
24
25#include <asm/hardware/sa1111.h>
26
27struct ps2if {
28	struct serio		*io;
29	struct sa1111_dev	*dev;
30	void __iomem		*base;
31	unsigned int		open;
32	spinlock_t		lock;
33	unsigned int		head;
34	unsigned int		tail;
35	unsigned char		buf[4];
36};
37
38/*
39 * Read all bytes waiting in the PS2 port.  There should be
40 * at the most one, but we loop for safety.  If there was a
41 * framing error, we have to manually clear the status.
42 */
43static irqreturn_t ps2_rxint(int irq, void *dev_id)
44{
45	struct ps2if *ps2if = dev_id;
46	unsigned int scancode, flag, status;
47
48	status = sa1111_readl(ps2if->base + SA1111_PS2STAT);
49	while (status & PS2STAT_RXF) {
50		if (status & PS2STAT_STP)
51			sa1111_writel(PS2STAT_STP, ps2if->base + SA1111_PS2STAT);
52
53		flag = (status & PS2STAT_STP ? SERIO_FRAME : 0) |
54		       (status & PS2STAT_RXP ? 0 : SERIO_PARITY);
55
56		scancode = sa1111_readl(ps2if->base + SA1111_PS2DATA) & 0xff;
57
58		if (hweight8(scancode) & 1)
59			flag ^= SERIO_PARITY;
60
61		serio_interrupt(ps2if->io, scancode, flag);
62
63		status = sa1111_readl(ps2if->base + SA1111_PS2STAT);
64        }
65
66        return IRQ_HANDLED;
67}
68
69/*
70 * Completion of ps2 write
71 */
72static irqreturn_t ps2_txint(int irq, void *dev_id)
73{
74	struct ps2if *ps2if = dev_id;
75	unsigned int status;
76
77	spin_lock(&ps2if->lock);
78	status = sa1111_readl(ps2if->base + SA1111_PS2STAT);
79	if (ps2if->head == ps2if->tail) {
80		disable_irq(irq);
81		/* done */
82	} else if (status & PS2STAT_TXE) {
83		sa1111_writel(ps2if->buf[ps2if->tail], ps2if->base + SA1111_PS2DATA);
84		ps2if->tail = (ps2if->tail + 1) & (sizeof(ps2if->buf) - 1);
85	}
86	spin_unlock(&ps2if->lock);
87
88	return IRQ_HANDLED;
89}
90
91/*
92 * Write a byte to the PS2 port.  We have to wait for the
93 * port to indicate that the transmitter is empty.
94 */
95static int ps2_write(struct serio *io, unsigned char val)
96{
97	struct ps2if *ps2if = io->port_data;
98	unsigned long flags;
99	unsigned int head;
100
101	spin_lock_irqsave(&ps2if->lock, flags);
102
103	/*
104	 * If the TX register is empty, we can go straight out.
105	 */
106	if (sa1111_readl(ps2if->base + SA1111_PS2STAT) & PS2STAT_TXE) {
107		sa1111_writel(val, ps2if->base + SA1111_PS2DATA);
108	} else {
109		if (ps2if->head == ps2if->tail)
110			enable_irq(ps2if->dev->irq[1]);
111		head = (ps2if->head + 1) & (sizeof(ps2if->buf) - 1);
112		if (head != ps2if->tail) {
113			ps2if->buf[ps2if->head] = val;
114			ps2if->head = head;
115		}
116	}
117
118	spin_unlock_irqrestore(&ps2if->lock, flags);
119	return 0;
120}
121
122static int ps2_open(struct serio *io)
123{
124	struct ps2if *ps2if = io->port_data;
125	int ret;
126
127	sa1111_enable_device(ps2if->dev);
128
129	ret = request_irq(ps2if->dev->irq[0], ps2_rxint, 0,
130			  SA1111_DRIVER_NAME(ps2if->dev), ps2if);
131	if (ret) {
132		printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
133			ps2if->dev->irq[0], ret);
134		return ret;
135	}
136
137	ret = request_irq(ps2if->dev->irq[1], ps2_txint, 0,
138			  SA1111_DRIVER_NAME(ps2if->dev), ps2if);
139	if (ret) {
140		printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
141			ps2if->dev->irq[1], ret);
142		free_irq(ps2if->dev->irq[0], ps2if);
143		return ret;
144	}
145
146	ps2if->open = 1;
147
148	enable_irq_wake(ps2if->dev->irq[0]);
149
150	sa1111_writel(PS2CR_ENA, ps2if->base + SA1111_PS2CR);
151	return 0;
152}
153
154static void ps2_close(struct serio *io)
155{
156	struct ps2if *ps2if = io->port_data;
157
158	sa1111_writel(0, ps2if->base + SA1111_PS2CR);
159
160	disable_irq_wake(ps2if->dev->irq[0]);
161
162	ps2if->open = 0;
163
164	free_irq(ps2if->dev->irq[1], ps2if);
165	free_irq(ps2if->dev->irq[0], ps2if);
166
167	sa1111_disable_device(ps2if->dev);
168}
169
170/*
171 * Clear the input buffer.
172 */
173static void __devinit ps2_clear_input(struct ps2if *ps2if)
174{
175	int maxread = 100;
176
177	while (maxread--) {
178		if ((sa1111_readl(ps2if->base + SA1111_PS2DATA) & 0xff) == 0xff)
179			break;
180	}
181}
182
183static inline unsigned int
184ps2_test_one(struct ps2if *ps2if, unsigned int mask)
185{
186	unsigned int val;
187
188	sa1111_writel(PS2CR_ENA | mask, ps2if->base + SA1111_PS2CR);
189
190	udelay(2);
191
192	val = sa1111_readl(ps2if->base + SA1111_PS2STAT);
193	return val & (PS2STAT_KBC | PS2STAT_KBD);
194}
195
196/*
197 * Test the keyboard interface.  We basically check to make sure that
198 * we can drive each line to the keyboard independently of each other.
199 */
200static int __init ps2_test(struct ps2if *ps2if)
201{
202	unsigned int stat;
203	int ret = 0;
204
205	stat = ps2_test_one(ps2if, PS2CR_FKC);
206	if (stat != PS2STAT_KBD) {
207		printk("PS/2 interface test failed[1]: %02x\n", stat);
208		ret = -ENODEV;
209	}
210
211	stat = ps2_test_one(ps2if, 0);
212	if (stat != (PS2STAT_KBC | PS2STAT_KBD)) {
213		printk("PS/2 interface test failed[2]: %02x\n", stat);
214		ret = -ENODEV;
215	}
216
217	stat = ps2_test_one(ps2if, PS2CR_FKD);
218	if (stat != PS2STAT_KBC) {
219		printk("PS/2 interface test failed[3]: %02x\n", stat);
220		ret = -ENODEV;
221	}
222
223	sa1111_writel(0, ps2if->base + SA1111_PS2CR);
224
225	return ret;
226}
227
228/*
229 * Add one device to this driver.
230 */
231static int __devinit ps2_probe(struct sa1111_dev *dev)
232{
233	struct ps2if *ps2if;
234	struct serio *serio;
235	int ret;
236
237	ps2if = kmalloc(sizeof(struct ps2if), GFP_KERNEL);
238	serio = kmalloc(sizeof(struct serio), GFP_KERNEL);
239	if (!ps2if || !serio) {
240		ret = -ENOMEM;
241		goto free;
242	}
243
244	memset(ps2if, 0, sizeof(struct ps2if));
245	memset(serio, 0, sizeof(struct serio));
246
247	serio->id.type		= SERIO_8042;
248	serio->write		= ps2_write;
249	serio->open		= ps2_open;
250	serio->close		= ps2_close;
251	strlcpy(serio->name, dev->dev.bus_id, sizeof(serio->name));
252	strlcpy(serio->phys, dev->dev.bus_id, sizeof(serio->phys));
253	serio->port_data	= ps2if;
254	serio->dev.parent	= &dev->dev;
255	ps2if->io		= serio;
256	ps2if->dev		= dev;
257	sa1111_set_drvdata(dev, ps2if);
258
259	spin_lock_init(&ps2if->lock);
260
261	/*
262	 * Request the physical region for this PS2 port.
263	 */
264	if (!request_mem_region(dev->res.start,
265				dev->res.end - dev->res.start + 1,
266				SA1111_DRIVER_NAME(dev))) {
267		ret = -EBUSY;
268		goto free;
269	}
270
271	/*
272	 * Our parent device has already mapped the region.
273	 */
274	ps2if->base = dev->mapbase;
275
276	sa1111_enable_device(ps2if->dev);
277
278	/* Incoming clock is 8MHz */
279	sa1111_writel(0, ps2if->base + SA1111_PS2CLKDIV);
280	sa1111_writel(127, ps2if->base + SA1111_PS2PRECNT);
281
282	/*
283	 * Flush any pending input.
284	 */
285	ps2_clear_input(ps2if);
286
287	/*
288	 * Test the keyboard interface.
289	 */
290	ret = ps2_test(ps2if);
291	if (ret)
292		goto out;
293
294	/*
295	 * Flush any pending input.
296	 */
297	ps2_clear_input(ps2if);
298
299	sa1111_disable_device(ps2if->dev);
300	serio_register_port(ps2if->io);
301	return 0;
302
303 out:
304	sa1111_disable_device(ps2if->dev);
305	release_mem_region(dev->res.start,
306			   dev->res.end - dev->res.start + 1);
307 free:
308	sa1111_set_drvdata(dev, NULL);
309	kfree(ps2if);
310	kfree(serio);
311	return ret;
312}
313
314/*
315 * Remove one device from this driver.
316 */
317static int ps2_remove(struct sa1111_dev *dev)
318{
319	struct ps2if *ps2if = sa1111_get_drvdata(dev);
320
321	serio_unregister_port(ps2if->io);
322	release_mem_region(dev->res.start,
323			   dev->res.end - dev->res.start + 1);
324	sa1111_set_drvdata(dev, NULL);
325
326	kfree(ps2if);
327
328	return 0;
329}
330
331/*
332 * Our device driver structure
333 */
334static struct sa1111_driver ps2_driver = {
335	.drv = {
336		.name	= "sa1111-ps2",
337	},
338	.devid		= SA1111_DEVID_PS2,
339	.probe		= ps2_probe,
340	.remove		= ps2_remove,
341};
342
343static int __init ps2_init(void)
344{
345	return sa1111_driver_register(&ps2_driver);
346}
347
348static void __exit ps2_exit(void)
349{
350	sa1111_driver_unregister(&ps2_driver);
351}
352
353module_init(ps2_init);
354module_exit(ps2_exit);
355
356MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
357MODULE_DESCRIPTION("SA1111 PS2 controller driver");
358MODULE_LICENSE("GPL");
359