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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
43struct 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 */
61static 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 */
90static irqreturn_t ps2_txint(int irq, void *dev_id)
91{
92 struct ps2if *ps2if = dev_id;
93 unsigned int status;
94
95 guard(spinlock)(&ps2if->lock);
96
97 status = readl_relaxed(ps2if->base + PS2STAT);
98 if (ps2if->head == ps2if->tail) {
99 disable_irq_nosync(irq);
100 /* done */
101 } else if (status & PS2STAT_TXE) {
102 writel_relaxed(ps2if->buf[ps2if->tail], ps2if->base + PS2DATA);
103 ps2if->tail = (ps2if->tail + 1) & (sizeof(ps2if->buf) - 1);
104 }
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 */
113static int ps2_write(struct serio *io, unsigned char val)
114{
115 struct ps2if *ps2if = io->port_data;
116 unsigned int head;
117
118 guard(spinlock_irqsave)(&ps2if->lock);
119
120 /*
121 * If the TX register is empty, we can go straight out.
122 */
123 if (readl_relaxed(ps2if->base + PS2STAT) & PS2STAT_TXE) {
124 writel_relaxed(val, ps2if->base + PS2DATA);
125 } else {
126 if (ps2if->head == ps2if->tail)
127 enable_irq(ps2if->tx_irq);
128 head = (ps2if->head + 1) & (sizeof(ps2if->buf) - 1);
129 if (head != ps2if->tail) {
130 ps2if->buf[ps2if->head] = val;
131 ps2if->head = head;
132 }
133 }
134
135 return 0;
136}
137
138static int ps2_open(struct serio *io)
139{
140 struct ps2if *ps2if = io->port_data;
141 int ret;
142
143 ret = sa1111_enable_device(ps2if->dev);
144 if (ret)
145 return ret;
146
147 ret = request_irq(ps2if->rx_irq, ps2_rxint, 0,
148 SA1111_DRIVER_NAME(ps2if->dev), ps2if);
149 if (ret) {
150 printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
151 ps2if->rx_irq, ret);
152 sa1111_disable_device(ps2if->dev);
153 return ret;
154 }
155
156 ret = request_irq(ps2if->tx_irq, ps2_txint, 0,
157 SA1111_DRIVER_NAME(ps2if->dev), ps2if);
158 if (ret) {
159 printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
160 ps2if->tx_irq, ret);
161 free_irq(ps2if->rx_irq, ps2if);
162 sa1111_disable_device(ps2if->dev);
163 return ret;
164 }
165
166 ps2if->open = 1;
167
168 enable_irq_wake(ps2if->rx_irq);
169
170 writel_relaxed(PS2CR_ENA, ps2if->base + PS2CR);
171 return 0;
172}
173
174static void ps2_close(struct serio *io)
175{
176 struct ps2if *ps2if = io->port_data;
177
178 writel_relaxed(0, ps2if->base + PS2CR);
179
180 disable_irq_wake(ps2if->rx_irq);
181
182 ps2if->open = 0;
183
184 free_irq(ps2if->tx_irq, ps2if);
185 free_irq(ps2if->rx_irq, ps2if);
186
187 sa1111_disable_device(ps2if->dev);
188}
189
190/*
191 * Clear the input buffer.
192 */
193static void ps2_clear_input(struct ps2if *ps2if)
194{
195 int maxread = 100;
196
197 while (maxread--) {
198 if ((readl_relaxed(ps2if->base + PS2DATA) & 0xff) == 0xff)
199 break;
200 }
201}
202
203static unsigned int ps2_test_one(struct ps2if *ps2if,
204 unsigned int mask)
205{
206 unsigned int val;
207
208 writel_relaxed(PS2CR_ENA | mask, ps2if->base + PS2CR);
209
210 udelay(10);
211
212 val = readl_relaxed(ps2if->base + PS2STAT);
213 return val & (PS2STAT_KBC | PS2STAT_KBD);
214}
215
216/*
217 * Test the keyboard interface. We basically check to make sure that
218 * we can drive each line to the keyboard independently of each other.
219 */
220static int ps2_test(struct ps2if *ps2if)
221{
222 unsigned int stat;
223 int ret = 0;
224
225 stat = ps2_test_one(ps2if, PS2CR_FKC);
226 if (stat != PS2STAT_KBD) {
227 printk("PS/2 interface test failed[1]: %02x\n", stat);
228 ret = -ENODEV;
229 }
230
231 stat = ps2_test_one(ps2if, 0);
232 if (stat != (PS2STAT_KBC | PS2STAT_KBD)) {
233 printk("PS/2 interface test failed[2]: %02x\n", stat);
234 ret = -ENODEV;
235 }
236
237 stat = ps2_test_one(ps2if, PS2CR_FKD);
238 if (stat != PS2STAT_KBC) {
239 printk("PS/2 interface test failed[3]: %02x\n", stat);
240 ret = -ENODEV;
241 }
242
243 writel_relaxed(0, ps2if->base + PS2CR);
244
245 return ret;
246}
247
248/*
249 * Add one device to this driver.
250 */
251static int ps2_probe(struct sa1111_dev *dev)
252{
253 struct ps2if *ps2if;
254 struct serio *serio;
255 int ret;
256
257 ps2if = kzalloc_obj(*ps2if);
258 serio = kzalloc_obj(*serio);
259 if (!ps2if || !serio) {
260 ret = -ENOMEM;
261 goto free;
262 }
263
264 serio->id.type = SERIO_8042;
265 serio->write = ps2_write;
266 serio->open = ps2_open;
267 serio->close = ps2_close;
268 strscpy(serio->name, dev_name(&dev->dev), sizeof(serio->name));
269 strscpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
270 serio->port_data = ps2if;
271 serio->dev.parent = &dev->dev;
272 ps2if->io = serio;
273 ps2if->dev = dev;
274 sa1111_set_drvdata(dev, ps2if);
275
276 spin_lock_init(&ps2if->lock);
277
278 ps2if->rx_irq = sa1111_get_irq(dev, 0);
279 if (ps2if->rx_irq <= 0) {
280 ret = ps2if->rx_irq ? : -ENXIO;
281 goto free;
282 }
283
284 ps2if->tx_irq = sa1111_get_irq(dev, 1);
285 if (ps2if->tx_irq <= 0) {
286 ret = ps2if->tx_irq ? : -ENXIO;
287 goto free;
288 }
289
290 /*
291 * Request the physical region for this PS2 port.
292 */
293 if (!request_mem_region(dev->res.start,
294 dev->res.end - dev->res.start + 1,
295 SA1111_DRIVER_NAME(dev))) {
296 ret = -EBUSY;
297 goto free;
298 }
299
300 /*
301 * Our parent device has already mapped the region.
302 */
303 ps2if->base = dev->mapbase;
304
305 sa1111_enable_device(ps2if->dev);
306
307 /* Incoming clock is 8MHz */
308 writel_relaxed(0, ps2if->base + PS2CLKDIV);
309 writel_relaxed(127, ps2if->base + PS2PRECNT);
310
311 /*
312 * Flush any pending input.
313 */
314 ps2_clear_input(ps2if);
315
316 /*
317 * Test the keyboard interface.
318 */
319 ret = ps2_test(ps2if);
320 if (ret)
321 goto out;
322
323 /*
324 * Flush any pending input.
325 */
326 ps2_clear_input(ps2if);
327
328 sa1111_disable_device(ps2if->dev);
329 serio_register_port(ps2if->io);
330 return 0;
331
332 out:
333 sa1111_disable_device(ps2if->dev);
334 release_mem_region(dev->res.start, resource_size(&dev->res));
335 free:
336 sa1111_set_drvdata(dev, NULL);
337 kfree(ps2if);
338 kfree(serio);
339 return ret;
340}
341
342/*
343 * Remove one device from this driver.
344 */
345static void ps2_remove(struct sa1111_dev *dev)
346{
347 struct ps2if *ps2if = sa1111_get_drvdata(dev);
348
349 serio_unregister_port(ps2if->io);
350 release_mem_region(dev->res.start, resource_size(&dev->res));
351 sa1111_set_drvdata(dev, NULL);
352
353 kfree(ps2if);
354}
355
356/*
357 * Our device driver structure
358 */
359static struct sa1111_driver ps2_driver = {
360 .drv = {
361 .name = "sa1111-ps2",
362 .owner = THIS_MODULE,
363 },
364 .devid = SA1111_DEVID_PS2,
365 .probe = ps2_probe,
366 .remove = ps2_remove,
367};
368
369static int __init ps2_init(void)
370{
371 return sa1111_driver_register(&ps2_driver);
372}
373
374static void __exit ps2_exit(void)
375{
376 sa1111_driver_unregister(&ps2_driver);
377}
378
379module_init(ps2_init);
380module_exit(ps2_exit);
381
382MODULE_AUTHOR("Russell King <[email protected]>");
383MODULE_DESCRIPTION("SA1111 PS2 controller driver");
384MODULE_LICENSE("GPL");