xref: /openbmc/linux/drivers/input/serio/sa1111ps2.c (revision 87c2ce3b) 
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 
27 struct 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  */
43 static irqreturn_t ps2_rxint(int irq, void *dev_id, struct pt_regs *regs)
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, regs);
62 
63 		status = sa1111_readl(ps2if->base + SA1111_PS2STAT);
64         }
65 
66         return IRQ_HANDLED;
67 }
68 
69 /*
70  * Completion of ps2 write
71  */
72 static irqreturn_t ps2_txint(int irq, void *dev_id, struct pt_regs *regs)
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  */
95 static 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 
122 static 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 
154 static 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  */
173 static void __init 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 
183 static inline unsigned int
184 ps2_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  */
200 static 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  */
231 static int 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  */
317 static 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  */
334 static 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 
343 static int __init ps2_init(void)
344 {
345 	return sa1111_driver_register(&ps2_driver);
346 }
347 
348 static void __exit ps2_exit(void)
349 {
350 	sa1111_driver_unregister(&ps2_driver);
351 }
352 
353 module_init(ps2_init);
354 module_exit(ps2_exit);
355 
356 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
357 MODULE_DESCRIPTION("SA1111 PS2 controller driver");
358 MODULE_LICENSE("GPL");
359