xref: /openbmc/linux/drivers/input/serio/sa1111ps2.c (revision 4f3db074) 
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 
24 #include <asm/hardware/sa1111.h>
25 
26 #define PS2CR		0x0000
27 #define PS2STAT		0x0004
28 #define PS2DATA		0x0008
29 #define PS2CLKDIV	0x000c
30 #define PS2PRECNT	0x0010
31 
32 #define PS2CR_ENA	0x08
33 #define PS2CR_FKD	0x02
34 #define PS2CR_FKC	0x01
35 
36 #define PS2STAT_STP	0x0100
37 #define PS2STAT_TXE	0x0080
38 #define PS2STAT_TXB	0x0040
39 #define PS2STAT_RXF	0x0020
40 #define PS2STAT_RXB	0x0010
41 #define PS2STAT_ENA	0x0008
42 #define PS2STAT_RXP	0x0004
43 #define PS2STAT_KBD	0x0002
44 #define PS2STAT_KBC	0x0001
45 
46 struct ps2if {
47 	struct serio		*io;
48 	struct sa1111_dev	*dev;
49 	void __iomem		*base;
50 	unsigned int		open;
51 	spinlock_t		lock;
52 	unsigned int		head;
53 	unsigned int		tail;
54 	unsigned char		buf[4];
55 };
56 
57 /*
58  * Read all bytes waiting in the PS2 port.  There should be
59  * at the most one, but we loop for safety.  If there was a
60  * framing error, we have to manually clear the status.
61  */
62 static irqreturn_t ps2_rxint(int irq, void *dev_id)
63 {
64 	struct ps2if *ps2if = dev_id;
65 	unsigned int scancode, flag, status;
66 
67 	status = sa1111_readl(ps2if->base + PS2STAT);
68 	while (status & PS2STAT_RXF) {
69 		if (status & PS2STAT_STP)
70 			sa1111_writel(PS2STAT_STP, ps2if->base + PS2STAT);
71 
72 		flag = (status & PS2STAT_STP ? SERIO_FRAME : 0) |
73 		       (status & PS2STAT_RXP ? 0 : SERIO_PARITY);
74 
75 		scancode = sa1111_readl(ps2if->base + PS2DATA) & 0xff;
76 
77 		if (hweight8(scancode) & 1)
78 			flag ^= SERIO_PARITY;
79 
80 		serio_interrupt(ps2if->io, scancode, flag);
81 
82 		status = sa1111_readl(ps2if->base + PS2STAT);
83         }
84 
85         return IRQ_HANDLED;
86 }
87 
88 /*
89  * Completion of ps2 write
90  */
91 static irqreturn_t ps2_txint(int irq, void *dev_id)
92 {
93 	struct ps2if *ps2if = dev_id;
94 	unsigned int status;
95 
96 	spin_lock(&ps2if->lock);
97 	status = sa1111_readl(ps2if->base + PS2STAT);
98 	if (ps2if->head == ps2if->tail) {
99 		disable_irq_nosync(irq);
100 		/* done */
101 	} else if (status & PS2STAT_TXE) {
102 		sa1111_writel(ps2if->buf[ps2if->tail], ps2if->base + PS2DATA);
103 		ps2if->tail = (ps2if->tail + 1) & (sizeof(ps2if->buf) - 1);
104 	}
105 	spin_unlock(&ps2if->lock);
106 
107 	return IRQ_HANDLED;
108 }
109 
110 /*
111  * Write a byte to the PS2 port.  We have to wait for the
112  * port to indicate that the transmitter is empty.
113  */
114 static int ps2_write(struct serio *io, unsigned char val)
115 {
116 	struct ps2if *ps2if = io->port_data;
117 	unsigned long flags;
118 	unsigned int head;
119 
120 	spin_lock_irqsave(&ps2if->lock, flags);
121 
122 	/*
123 	 * If the TX register is empty, we can go straight out.
124 	 */
125 	if (sa1111_readl(ps2if->base + PS2STAT) & PS2STAT_TXE) {
126 		sa1111_writel(val, ps2if->base + PS2DATA);
127 	} else {
128 		if (ps2if->head == ps2if->tail)
129 			enable_irq(ps2if->dev->irq[1]);
130 		head = (ps2if->head + 1) & (sizeof(ps2if->buf) - 1);
131 		if (head != ps2if->tail) {
132 			ps2if->buf[ps2if->head] = val;
133 			ps2if->head = head;
134 		}
135 	}
136 
137 	spin_unlock_irqrestore(&ps2if->lock, flags);
138 	return 0;
139 }
140 
141 static int ps2_open(struct serio *io)
142 {
143 	struct ps2if *ps2if = io->port_data;
144 	int ret;
145 
146 	ret = sa1111_enable_device(ps2if->dev);
147 	if (ret)
148 		return ret;
149 
150 	ret = request_irq(ps2if->dev->irq[0], ps2_rxint, 0,
151 			  SA1111_DRIVER_NAME(ps2if->dev), ps2if);
152 	if (ret) {
153 		printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
154 			ps2if->dev->irq[0], ret);
155 		sa1111_disable_device(ps2if->dev);
156 		return ret;
157 	}
158 
159 	ret = request_irq(ps2if->dev->irq[1], ps2_txint, 0,
160 			  SA1111_DRIVER_NAME(ps2if->dev), ps2if);
161 	if (ret) {
162 		printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
163 			ps2if->dev->irq[1], ret);
164 		free_irq(ps2if->dev->irq[0], ps2if);
165 		sa1111_disable_device(ps2if->dev);
166 		return ret;
167 	}
168 
169 	ps2if->open = 1;
170 
171 	enable_irq_wake(ps2if->dev->irq[0]);
172 
173 	sa1111_writel(PS2CR_ENA, ps2if->base + PS2CR);
174 	return 0;
175 }
176 
177 static void ps2_close(struct serio *io)
178 {
179 	struct ps2if *ps2if = io->port_data;
180 
181 	sa1111_writel(0, ps2if->base + PS2CR);
182 
183 	disable_irq_wake(ps2if->dev->irq[0]);
184 
185 	ps2if->open = 0;
186 
187 	free_irq(ps2if->dev->irq[1], ps2if);
188 	free_irq(ps2if->dev->irq[0], ps2if);
189 
190 	sa1111_disable_device(ps2if->dev);
191 }
192 
193 /*
194  * Clear the input buffer.
195  */
196 static void ps2_clear_input(struct ps2if *ps2if)
197 {
198 	int maxread = 100;
199 
200 	while (maxread--) {
201 		if ((sa1111_readl(ps2if->base + PS2DATA) & 0xff) == 0xff)
202 			break;
203 	}
204 }
205 
206 static unsigned int ps2_test_one(struct ps2if *ps2if,
207 					   unsigned int mask)
208 {
209 	unsigned int val;
210 
211 	sa1111_writel(PS2CR_ENA | mask, ps2if->base + PS2CR);
212 
213 	udelay(2);
214 
215 	val = sa1111_readl(ps2if->base + PS2STAT);
216 	return val & (PS2STAT_KBC | PS2STAT_KBD);
217 }
218 
219 /*
220  * Test the keyboard interface.  We basically check to make sure that
221  * we can drive each line to the keyboard independently of each other.
222  */
223 static int ps2_test(struct ps2if *ps2if)
224 {
225 	unsigned int stat;
226 	int ret = 0;
227 
228 	stat = ps2_test_one(ps2if, PS2CR_FKC);
229 	if (stat != PS2STAT_KBD) {
230 		printk("PS/2 interface test failed[1]: %02x\n", stat);
231 		ret = -ENODEV;
232 	}
233 
234 	stat = ps2_test_one(ps2if, 0);
235 	if (stat != (PS2STAT_KBC | PS2STAT_KBD)) {
236 		printk("PS/2 interface test failed[2]: %02x\n", stat);
237 		ret = -ENODEV;
238 	}
239 
240 	stat = ps2_test_one(ps2if, PS2CR_FKD);
241 	if (stat != PS2STAT_KBC) {
242 		printk("PS/2 interface test failed[3]: %02x\n", stat);
243 		ret = -ENODEV;
244 	}
245 
246 	sa1111_writel(0, ps2if->base + PS2CR);
247 
248 	return ret;
249 }
250 
251 /*
252  * Add one device to this driver.
253  */
254 static int ps2_probe(struct sa1111_dev *dev)
255 {
256 	struct ps2if *ps2if;
257 	struct serio *serio;
258 	int ret;
259 
260 	ps2if = kzalloc(sizeof(struct ps2if), GFP_KERNEL);
261 	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
262 	if (!ps2if || !serio) {
263 		ret = -ENOMEM;
264 		goto free;
265 	}
266 
267 
268 	serio->id.type		= SERIO_8042;
269 	serio->write		= ps2_write;
270 	serio->open		= ps2_open;
271 	serio->close		= ps2_close;
272 	strlcpy(serio->name, dev_name(&dev->dev), sizeof(serio->name));
273 	strlcpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
274 	serio->port_data	= ps2if;
275 	serio->dev.parent	= &dev->dev;
276 	ps2if->io		= serio;
277 	ps2if->dev		= dev;
278 	sa1111_set_drvdata(dev, ps2if);
279 
280 	spin_lock_init(&ps2if->lock);
281 
282 	/*
283 	 * Request the physical region for this PS2 port.
284 	 */
285 	if (!request_mem_region(dev->res.start,
286 				dev->res.end - dev->res.start + 1,
287 				SA1111_DRIVER_NAME(dev))) {
288 		ret = -EBUSY;
289 		goto free;
290 	}
291 
292 	/*
293 	 * Our parent device has already mapped the region.
294 	 */
295 	ps2if->base = dev->mapbase;
296 
297 	sa1111_enable_device(ps2if->dev);
298 
299 	/* Incoming clock is 8MHz */
300 	sa1111_writel(0, ps2if->base + PS2CLKDIV);
301 	sa1111_writel(127, ps2if->base + PS2PRECNT);
302 
303 	/*
304 	 * Flush any pending input.
305 	 */
306 	ps2_clear_input(ps2if);
307 
308 	/*
309 	 * Test the keyboard interface.
310 	 */
311 	ret = ps2_test(ps2if);
312 	if (ret)
313 		goto out;
314 
315 	/*
316 	 * Flush any pending input.
317 	 */
318 	ps2_clear_input(ps2if);
319 
320 	sa1111_disable_device(ps2if->dev);
321 	serio_register_port(ps2if->io);
322 	return 0;
323 
324  out:
325 	sa1111_disable_device(ps2if->dev);
326 	release_mem_region(dev->res.start, resource_size(&dev->res));
327  free:
328 	sa1111_set_drvdata(dev, NULL);
329 	kfree(ps2if);
330 	kfree(serio);
331 	return ret;
332 }
333 
334 /*
335  * Remove one device from this driver.
336  */
337 static int ps2_remove(struct sa1111_dev *dev)
338 {
339 	struct ps2if *ps2if = sa1111_get_drvdata(dev);
340 
341 	serio_unregister_port(ps2if->io);
342 	release_mem_region(dev->res.start, resource_size(&dev->res));
343 	sa1111_set_drvdata(dev, NULL);
344 
345 	kfree(ps2if);
346 
347 	return 0;
348 }
349 
350 /*
351  * Our device driver structure
352  */
353 static struct sa1111_driver ps2_driver = {
354 	.drv = {
355 		.name	= "sa1111-ps2",
356 		.owner	= THIS_MODULE,
357 	},
358 	.devid		= SA1111_DEVID_PS2,
359 	.probe		= ps2_probe,
360 	.remove		= ps2_remove,
361 };
362 
363 static int __init ps2_init(void)
364 {
365 	return sa1111_driver_register(&ps2_driver);
366 }
367 
368 static void __exit ps2_exit(void)
369 {
370 	sa1111_driver_unregister(&ps2_driver);
371 }
372 
373 module_init(ps2_init);
374 module_exit(ps2_exit);
375 
376 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
377 MODULE_DESCRIPTION("SA1111 PS2 controller driver");
378 MODULE_LICENSE("GPL");
379