1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/drivers/input/serio/sa1111ps2.c
4 *
5 * Copyright (C) 2002 Russell King
6 */
7 #include <linux/module.h>
8 #include <linux/init.h>
9 #include <linux/input.h>
10 #include <linux/serio.h>
11 #include <linux/errno.h>
12 #include <linux/interrupt.h>
13 #include <linux/ioport.h>
14 #include <linux/delay.h>
15 #include <linux/device.h>
16 #include <linux/slab.h>
17 #include <linux/spinlock.h>
18
19 #include <asm/io.h>
20
21 #include <asm/hardware/sa1111.h>
22
23 #define PS2CR 0x0000
24 #define PS2STAT 0x0004
25 #define PS2DATA 0x0008
26 #define PS2CLKDIV 0x000c
27 #define PS2PRECNT 0x0010
28
29 #define PS2CR_ENA 0x08
30 #define PS2CR_FKD 0x02
31 #define PS2CR_FKC 0x01
32
33 #define PS2STAT_STP 0x0100
34 #define PS2STAT_TXE 0x0080
35 #define PS2STAT_TXB 0x0040
36 #define PS2STAT_RXF 0x0020
37 #define PS2STAT_RXB 0x0010
38 #define PS2STAT_ENA 0x0008
39 #define PS2STAT_RXP 0x0004
40 #define PS2STAT_KBD 0x0002
41 #define PS2STAT_KBC 0x0001
42
43 struct ps2if {
44 struct serio *io;
45 struct sa1111_dev *dev;
46 void __iomem *base;
47 int rx_irq;
48 int tx_irq;
49 unsigned int open;
50 spinlock_t lock;
51 unsigned int head;
52 unsigned int tail;
53 unsigned char buf[4];
54 };
55
56 /*
57 * Read all bytes waiting in the PS2 port. There should be
58 * at the most one, but we loop for safety. If there was a
59 * framing error, we have to manually clear the status.
60 */
ps2_rxint(int irq,void * dev_id)61 static irqreturn_t ps2_rxint(int irq, void *dev_id)
62 {
63 struct ps2if *ps2if = dev_id;
64 unsigned int scancode, flag, status;
65
66 status = readl_relaxed(ps2if->base + PS2STAT);
67 while (status & PS2STAT_RXF) {
68 if (status & PS2STAT_STP)
69 writel_relaxed(PS2STAT_STP, ps2if->base + PS2STAT);
70
71 flag = (status & PS2STAT_STP ? SERIO_FRAME : 0) |
72 (status & PS2STAT_RXP ? 0 : SERIO_PARITY);
73
74 scancode = readl_relaxed(ps2if->base + PS2DATA) & 0xff;
75
76 if (hweight8(scancode) & 1)
77 flag ^= SERIO_PARITY;
78
79 serio_interrupt(ps2if->io, scancode, flag);
80
81 status = readl_relaxed(ps2if->base + PS2STAT);
82 }
83
84 return IRQ_HANDLED;
85 }
86
87 /*
88 * Completion of ps2 write
89 */
ps2_txint(int irq,void * dev_id)90 static irqreturn_t ps2_txint(int irq, void *dev_id)
91 {
92 struct ps2if *ps2if = dev_id;
93 unsigned int status;
94
95 spin_lock(&ps2if->lock);
96 status = readl_relaxed(ps2if->base + PS2STAT);
97 if (ps2if->head == ps2if->tail) {
98 disable_irq_nosync(irq);
99 /* done */
100 } else if (status & PS2STAT_TXE) {
101 writel_relaxed(ps2if->buf[ps2if->tail], ps2if->base + PS2DATA);
102 ps2if->tail = (ps2if->tail + 1) & (sizeof(ps2if->buf) - 1);
103 }
104 spin_unlock(&ps2if->lock);
105
106 return IRQ_HANDLED;
107 }
108
109 /*
110 * Write a byte to the PS2 port. We have to wait for the
111 * port to indicate that the transmitter is empty.
112 */
ps2_write(struct serio * io,unsigned char val)113 static int ps2_write(struct serio *io, unsigned char val)
114 {
115 struct ps2if *ps2if = io->port_data;
116 unsigned long flags;
117 unsigned int head;
118
119 spin_lock_irqsave(&ps2if->lock, flags);
120
121 /*
122 * If the TX register is empty, we can go straight out.
123 */
124 if (readl_relaxed(ps2if->base + PS2STAT) & PS2STAT_TXE) {
125 writel_relaxed(val, ps2if->base + PS2DATA);
126 } else {
127 if (ps2if->head == ps2if->tail)
128 enable_irq(ps2if->tx_irq);
129 head = (ps2if->head + 1) & (sizeof(ps2if->buf) - 1);
130 if (head != ps2if->tail) {
131 ps2if->buf[ps2if->head] = val;
132 ps2if->head = head;
133 }
134 }
135
136 spin_unlock_irqrestore(&ps2if->lock, flags);
137 return 0;
138 }
139
ps2_open(struct serio * io)140 static int ps2_open(struct serio *io)
141 {
142 struct ps2if *ps2if = io->port_data;
143 int ret;
144
145 ret = sa1111_enable_device(ps2if->dev);
146 if (ret)
147 return ret;
148
149 ret = request_irq(ps2if->rx_irq, ps2_rxint, 0,
150 SA1111_DRIVER_NAME(ps2if->dev), ps2if);
151 if (ret) {
152 printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
153 ps2if->rx_irq, ret);
154 sa1111_disable_device(ps2if->dev);
155 return ret;
156 }
157
158 ret = request_irq(ps2if->tx_irq, ps2_txint, 0,
159 SA1111_DRIVER_NAME(ps2if->dev), ps2if);
160 if (ret) {
161 printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
162 ps2if->tx_irq, ret);
163 free_irq(ps2if->rx_irq, ps2if);
164 sa1111_disable_device(ps2if->dev);
165 return ret;
166 }
167
168 ps2if->open = 1;
169
170 enable_irq_wake(ps2if->rx_irq);
171
172 writel_relaxed(PS2CR_ENA, ps2if->base + PS2CR);
173 return 0;
174 }
175
ps2_close(struct serio * io)176 static void ps2_close(struct serio *io)
177 {
178 struct ps2if *ps2if = io->port_data;
179
180 writel_relaxed(0, ps2if->base + PS2CR);
181
182 disable_irq_wake(ps2if->rx_irq);
183
184 ps2if->open = 0;
185
186 free_irq(ps2if->tx_irq, ps2if);
187 free_irq(ps2if->rx_irq, ps2if);
188
189 sa1111_disable_device(ps2if->dev);
190 }
191
192 /*
193 * Clear the input buffer.
194 */
ps2_clear_input(struct ps2if * ps2if)195 static void ps2_clear_input(struct ps2if *ps2if)
196 {
197 int maxread = 100;
198
199 while (maxread--) {
200 if ((readl_relaxed(ps2if->base + PS2DATA) & 0xff) == 0xff)
201 break;
202 }
203 }
204
ps2_test_one(struct ps2if * ps2if,unsigned int mask)205 static unsigned int ps2_test_one(struct ps2if *ps2if,
206 unsigned int mask)
207 {
208 unsigned int val;
209
210 writel_relaxed(PS2CR_ENA | mask, ps2if->base + PS2CR);
211
212 udelay(10);
213
214 val = readl_relaxed(ps2if->base + PS2STAT);
215 return val & (PS2STAT_KBC | PS2STAT_KBD);
216 }
217
218 /*
219 * Test the keyboard interface. We basically check to make sure that
220 * we can drive each line to the keyboard independently of each other.
221 */
ps2_test(struct ps2if * ps2if)222 static int ps2_test(struct ps2if *ps2if)
223 {
224 unsigned int stat;
225 int ret = 0;
226
227 stat = ps2_test_one(ps2if, PS2CR_FKC);
228 if (stat != PS2STAT_KBD) {
229 printk("PS/2 interface test failed[1]: %02x\n", stat);
230 ret = -ENODEV;
231 }
232
233 stat = ps2_test_one(ps2if, 0);
234 if (stat != (PS2STAT_KBC | PS2STAT_KBD)) {
235 printk("PS/2 interface test failed[2]: %02x\n", stat);
236 ret = -ENODEV;
237 }
238
239 stat = ps2_test_one(ps2if, PS2CR_FKD);
240 if (stat != PS2STAT_KBC) {
241 printk("PS/2 interface test failed[3]: %02x\n", stat);
242 ret = -ENODEV;
243 }
244
245 writel_relaxed(0, ps2if->base + PS2CR);
246
247 return ret;
248 }
249
250 /*
251 * Add one device to this driver.
252 */
ps2_probe(struct sa1111_dev * dev)253 static int ps2_probe(struct sa1111_dev *dev)
254 {
255 struct ps2if *ps2if;
256 struct serio *serio;
257 int ret;
258
259 ps2if = kzalloc(sizeof(struct ps2if), GFP_KERNEL);
260 serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
261 if (!ps2if || !serio) {
262 ret = -ENOMEM;
263 goto free;
264 }
265
266 serio->id.type = SERIO_8042;
267 serio->write = ps2_write;
268 serio->open = ps2_open;
269 serio->close = ps2_close;
270 strlcpy(serio->name, dev_name(&dev->dev), sizeof(serio->name));
271 strlcpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
272 serio->port_data = ps2if;
273 serio->dev.parent = &dev->dev;
274 ps2if->io = serio;
275 ps2if->dev = dev;
276 sa1111_set_drvdata(dev, ps2if);
277
278 spin_lock_init(&ps2if->lock);
279
280 ps2if->rx_irq = sa1111_get_irq(dev, 0);
281 if (ps2if->rx_irq <= 0) {
282 ret = ps2if->rx_irq ? : -ENXIO;
283 goto free;
284 }
285
286 ps2if->tx_irq = sa1111_get_irq(dev, 1);
287 if (ps2if->tx_irq <= 0) {
288 ret = ps2if->tx_irq ? : -ENXIO;
289 goto free;
290 }
291
292 /*
293 * Request the physical region for this PS2 port.
294 */
295 if (!request_mem_region(dev->res.start,
296 dev->res.end - dev->res.start + 1,
297 SA1111_DRIVER_NAME(dev))) {
298 ret = -EBUSY;
299 goto free;
300 }
301
302 /*
303 * Our parent device has already mapped the region.
304 */
305 ps2if->base = dev->mapbase;
306
307 sa1111_enable_device(ps2if->dev);
308
309 /* Incoming clock is 8MHz */
310 writel_relaxed(0, ps2if->base + PS2CLKDIV);
311 writel_relaxed(127, ps2if->base + PS2PRECNT);
312
313 /*
314 * Flush any pending input.
315 */
316 ps2_clear_input(ps2if);
317
318 /*
319 * Test the keyboard interface.
320 */
321 ret = ps2_test(ps2if);
322 if (ret)
323 goto out;
324
325 /*
326 * Flush any pending input.
327 */
328 ps2_clear_input(ps2if);
329
330 sa1111_disable_device(ps2if->dev);
331 serio_register_port(ps2if->io);
332 return 0;
333
334 out:
335 sa1111_disable_device(ps2if->dev);
336 release_mem_region(dev->res.start, resource_size(&dev->res));
337 free:
338 sa1111_set_drvdata(dev, NULL);
339 kfree(ps2if);
340 kfree(serio);
341 return ret;
342 }
343
344 /*
345 * Remove one device from this driver.
346 */
ps2_remove(struct sa1111_dev * dev)347 static int ps2_remove(struct sa1111_dev *dev)
348 {
349 struct ps2if *ps2if = sa1111_get_drvdata(dev);
350
351 serio_unregister_port(ps2if->io);
352 release_mem_region(dev->res.start, resource_size(&dev->res));
353 sa1111_set_drvdata(dev, NULL);
354
355 kfree(ps2if);
356
357 return 0;
358 }
359
360 /*
361 * Our device driver structure
362 */
363 static struct sa1111_driver ps2_driver = {
364 .drv = {
365 .name = "sa1111-ps2",
366 .owner = THIS_MODULE,
367 },
368 .devid = SA1111_DEVID_PS2,
369 .probe = ps2_probe,
370 .remove = ps2_remove,
371 };
372
ps2_init(void)373 static int __init ps2_init(void)
374 {
375 return sa1111_driver_register(&ps2_driver);
376 }
377
ps2_exit(void)378 static void __exit ps2_exit(void)
379 {
380 sa1111_driver_unregister(&ps2_driver);
381 }
382
383 module_init(ps2_init);
384 module_exit(ps2_exit);
385
386 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
387 MODULE_DESCRIPTION("SA1111 PS2 controller driver");
388 MODULE_LICENSE("GPL");
389