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/drivers/input/serio/sa1111ps2.c

http://github.com/mirrors/linux
C | 388 lines | 264 code | 70 blank | 54 comment | 31 complexity | c99fdd75a62536c60e3c2191c6a5521a MD5 | raw file
  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	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 */
113static 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
140static 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
176static 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 */
195static 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
205static 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 */
222static 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 */
253static 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 */
347static 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 */
363static 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
373static int __init ps2_init(void)
374{
375	return sa1111_driver_register(&ps2_driver);
376}
377
378static void __exit ps2_exit(void)
379{
380	sa1111_driver_unregister(&ps2_driver);
381}
382
383module_init(ps2_init);
384module_exit(ps2_exit);
385
386MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
387MODULE_DESCRIPTION("SA1111 PS2 controller driver");
388MODULE_LICENSE("GPL");