summaryrefslogtreecommitdiff
path: root/drivers/net/wireless/cw1200/cw1200_spi.c
blob: 7603546d2de322cf8fb5dd5bf0d5ff3e48d8a6be (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
/*
 * Mac80211 SPI driver for ST-Ericsson CW1200 device
 *
 * Copyright (c) 2011, Sagrad Inc.
 * Author:  Solomon Peachy <speachy@sagrad.com>
 *
 * Based on cw1200_sdio.c
 * Copyright (c) 2010, ST-Ericsson
 * Author: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/gpio.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <net/mac80211.h>

#include <linux/spi/spi.h>
#include <linux/device.h>

#include "cw1200.h"
#include "hwbus.h"
#include <linux/platform_data/net-cw1200.h>
#include "hwio.h"

MODULE_AUTHOR("Solomon Peachy <speachy@sagrad.com>");
MODULE_DESCRIPTION("mac80211 ST-Ericsson CW1200 SPI driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("spi:cw1200_wlan_spi");

/* #define SPI_DEBUG */

struct hwbus_priv {
	struct spi_device	*func;
	struct cw1200_common	*core;
	const struct cw1200_platform_data_spi *pdata;
	spinlock_t		lock; /* Serialize all bus operations */
	wait_queue_head_t       wq;
	int claimed;
};

#define SDIO_TO_SPI_ADDR(addr) ((addr & 0x1f)>>2)
#define SET_WRITE 0x7FFF /* usage: and operation */
#define SET_READ 0x8000  /* usage: or operation */

/* Notes on byte ordering:
   LE:  B0 B1 B2 B3
   BE:  B3 B2 B1 B0

   Hardware expects 32-bit data to be written as 16-bit BE words:

   B1 B0 B3 B2
*/

static int cw1200_spi_memcpy_fromio(struct hwbus_priv *self,
				     unsigned int addr,
				     void *dst, int count)
{
	int ret, i;
	u16 regaddr;
	struct spi_message      m;

	struct spi_transfer     t_addr = {
		.tx_buf         = &regaddr,
		.len            = sizeof(regaddr),
	};
	struct spi_transfer     t_msg = {
		.rx_buf         = dst,
		.len            = count,
	};

	regaddr = (SDIO_TO_SPI_ADDR(addr))<<12;
	regaddr |= SET_READ;
	regaddr |= (count>>1);

#ifdef SPI_DEBUG
	pr_info("READ : %04d from 0x%02x (%04x)\n", count, addr, regaddr);
#endif

	/* Header is LE16 */
	regaddr = cpu_to_le16(regaddr);

	/* We have to byteswap if the SPI bus is limited to 8b operation
	   or we are running on a Big Endian system
	*/
#if defined(__LITTLE_ENDIAN)
	if (self->func->bits_per_word == 8)
#endif
		regaddr = swab16(regaddr);

	spi_message_init(&m);
	spi_message_add_tail(&t_addr, &m);
	spi_message_add_tail(&t_msg, &m);
	ret = spi_sync(self->func, &m);

#ifdef SPI_DEBUG
	pr_info("READ : ");
	for (i = 0; i < t_addr.len; i++)
		printk("%02x ", ((u8 *)t_addr.tx_buf)[i]);
	printk(" : ");
	for (i = 0; i < t_msg.len; i++)
		printk("%02x ", ((u8 *)t_msg.rx_buf)[i]);
	printk("\n");
#endif

	/* We have to byteswap if the SPI bus is limited to 8b operation
	   or we are running on a Big Endian system
	*/
#if defined(__LITTLE_ENDIAN)
	if (self->func->bits_per_word == 8)
#endif
	{
		uint16_t *buf = (uint16_t *)dst;
		for (i = 0; i < ((count + 1) >> 1); i++)
			buf[i] = swab16(buf[i]);
	}

	return ret;
}

static int cw1200_spi_memcpy_toio(struct hwbus_priv *self,
				   unsigned int addr,
				   const void *src, int count)
{
	int rval, i;
	u16 regaddr;
	struct spi_transfer     t_addr = {
		.tx_buf         = &regaddr,
		.len            = sizeof(regaddr),
	};
	struct spi_transfer     t_msg = {
		.tx_buf         = src,
		.len            = count,
	};
	struct spi_message      m;

	regaddr = (SDIO_TO_SPI_ADDR(addr))<<12;
	regaddr &= SET_WRITE;
	regaddr |= (count>>1);

#ifdef SPI_DEBUG
	pr_info("WRITE: %04d  to  0x%02x (%04x)\n", count, addr, regaddr);
#endif

	/* Header is LE16 */
	regaddr = cpu_to_le16(regaddr);

	/* We have to byteswap if the SPI bus is limited to 8b operation
	   or we are running on a Big Endian system
	*/
#if defined(__LITTLE_ENDIAN)
	if (self->func->bits_per_word == 8)
#endif
	{
		uint16_t *buf = (uint16_t *)src;
	        regaddr = swab16(regaddr);
		for (i = 0; i < ((count + 1) >> 1); i++)
			buf[i] = swab16(buf[i]);
	}

#ifdef SPI_DEBUG
	pr_info("WRITE: ");
	for (i = 0; i < t_addr.len; i++)
		printk("%02x ", ((u8 *)t_addr.tx_buf)[i]);
	printk(" : ");
	for (i = 0; i < t_msg.len; i++)
		printk("%02x ", ((u8 *)t_msg.tx_buf)[i]);
	printk("\n");
#endif

	spi_message_init(&m);
	spi_message_add_tail(&t_addr, &m);
	spi_message_add_tail(&t_msg, &m);
	rval = spi_sync(self->func, &m);

#ifdef SPI_DEBUG
	pr_info("WROTE: %d\n", m.actual_length);
#endif

#if defined(__LITTLE_ENDIAN)
	/* We have to byteswap if the SPI bus is limited to 8b operation */
	if (self->func->bits_per_word == 8)
#endif
	{
		uint16_t *buf = (uint16_t *)src;
		for (i = 0; i < ((count + 1) >> 1); i++)
			buf[i] = swab16(buf[i]);
	}
	return rval;
}

static void cw1200_spi_lock(struct hwbus_priv *self)
{
	unsigned long flags;

	DECLARE_WAITQUEUE(wait, current);

	might_sleep();

	add_wait_queue(&self->wq, &wait);
	spin_lock_irqsave(&self->lock, flags);
	while (1) {
		set_current_state(TASK_UNINTERRUPTIBLE);
		if (!self->claimed)
			break;
		spin_unlock_irqrestore(&self->lock, flags);
		schedule();
		spin_lock_irqsave(&self->lock, flags);
	}
	set_current_state(TASK_RUNNING);
	self->claimed = 1;
	spin_unlock_irqrestore(&self->lock, flags);
	remove_wait_queue(&self->wq, &wait);

	return;
}

static void cw1200_spi_unlock(struct hwbus_priv *self)
{
	unsigned long flags;

	spin_lock_irqsave(&self->lock, flags);
	self->claimed = 0;
	spin_unlock_irqrestore(&self->lock, flags);
	wake_up(&self->wq);

	return;
}

static irqreturn_t cw1200_spi_irq_handler(int irq, void *dev_id)
{
	struct hwbus_priv *self = dev_id;

	if (self->core) {
		cw1200_spi_lock(self);
		cw1200_irq_handler(self->core);
		cw1200_spi_unlock(self);
		return IRQ_HANDLED;
	} else {
		return IRQ_NONE;
	}
}

static int cw1200_spi_irq_subscribe(struct hwbus_priv *self)
{
	int ret;

	pr_debug("SW IRQ subscribe\n");

	ret = request_threaded_irq(self->func->irq, NULL,
				   cw1200_spi_irq_handler,
				   IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
				   "cw1200_wlan_irq", self);
	if (WARN_ON(ret < 0))
		goto exit;

	ret = enable_irq_wake(self->func->irq);
	if (WARN_ON(ret))
		goto free_irq;

	return 0;

free_irq:
	free_irq(self->func->irq, self);
exit:
	return ret;
}

static int cw1200_spi_irq_unsubscribe(struct hwbus_priv *self)
{
	int ret = 0;

	pr_debug("SW IRQ unsubscribe\n");
	disable_irq_wake(self->func->irq);
	free_irq(self->func->irq, self);

	return ret;
}

static int cw1200_spi_off(const struct cw1200_platform_data_spi *pdata)
{
	if (pdata->reset) {
		gpio_set_value(pdata->reset, 0);
		msleep(30); /* Min is 2 * CLK32K cycles */
		gpio_free(pdata->reset);
	}

	if (pdata->power_ctrl)
		pdata->power_ctrl(pdata, false);
	if (pdata->clk_ctrl)
		pdata->clk_ctrl(pdata, false);

	return 0;
}

static int cw1200_spi_on(const struct cw1200_platform_data_spi *pdata)
{
	/* Ensure I/Os are pulled low */
	if (pdata->reset) {
		gpio_request(pdata->reset, "cw1200_wlan_reset");
		gpio_direction_output(pdata->reset, 0);
	}
	if (pdata->powerup) {
		gpio_request(pdata->powerup, "cw1200_wlan_powerup");
		gpio_direction_output(pdata->powerup, 0);
	}
	if (pdata->reset || pdata->powerup)
		msleep(10); /* Settle time? */

	/* Enable 3v3 and 1v8 to hardware */
	if (pdata->power_ctrl) {
		if (pdata->power_ctrl(pdata, true)) {
			pr_err("power_ctrl() failed!\n");
			return -1;
		}
	}

	/* Enable CLK32K */
	if (pdata->clk_ctrl) {
		if (pdata->clk_ctrl(pdata, true)) {
			pr_err("clk_ctrl() failed!\n");
			return -1;
		}
		msleep(10); /* Delay until clock is stable for 2 cycles */
	}

	/* Enable POWERUP signal */
	if (pdata->powerup) {
		gpio_set_value(pdata->powerup, 1);
		msleep(250); /* or more..? */
	}
	/* Enable RSTn signal */
	if (pdata->reset) {
		gpio_set_value(pdata->reset, 1);
		msleep(50); /* Or more..? */
	}
	return 0;
}

static size_t cw1200_spi_align_size(struct hwbus_priv *self, size_t size)
{
	return size & 1 ? size + 1 : size;
}

static int cw1200_spi_pm(struct hwbus_priv *self, bool suspend)
{
	return irq_set_irq_wake(self->func->irq, suspend);
}

static struct hwbus_ops cw1200_spi_hwbus_ops = {
	.hwbus_memcpy_fromio	= cw1200_spi_memcpy_fromio,
	.hwbus_memcpy_toio	= cw1200_spi_memcpy_toio,
	.lock			= cw1200_spi_lock,
	.unlock			= cw1200_spi_unlock,
	.align_size		= cw1200_spi_align_size,
	.power_mgmt		= cw1200_spi_pm,
};

/* Probe Function to be called by SPI stack when device is discovered */
static int cw1200_spi_probe(struct spi_device *func)
{
	const struct cw1200_platform_data_spi *plat_data =
		dev_get_platdata(&func->dev);
	struct hwbus_priv *self;
	int status;

	/* Sanity check speed */
	if (func->max_speed_hz > 52000000)
		func->max_speed_hz = 52000000;
	if (func->max_speed_hz < 1000000)
		func->max_speed_hz = 1000000;

	/* Fix up transfer size */
	if (plat_data->spi_bits_per_word)
		func->bits_per_word = plat_data->spi_bits_per_word;
	if (!func->bits_per_word)
		func->bits_per_word = 16;

	/* And finally.. */
	func->mode = SPI_MODE_0;

	pr_info("cw1200_wlan_spi: Probe called (CS %d M %d BPW %d CLK %d)\n",
		func->chip_select, func->mode, func->bits_per_word,
		func->max_speed_hz);

	if (cw1200_spi_on(plat_data)) {
		pr_err("spi_on() failed!\n");
		return -1;
	}

	if (spi_setup(func)) {
		pr_err("spi_setup() failed!\n");
		return -1;
	}

	self = devm_kzalloc(&func->dev, sizeof(*self), GFP_KERNEL);
	if (!self) {
		pr_err("Can't allocate SPI hwbus_priv.");
		return -ENOMEM;
	}

	self->pdata = plat_data;
	self->func = func;
	spin_lock_init(&self->lock);

	spi_set_drvdata(func, self);

	init_waitqueue_head(&self->wq);

	status = cw1200_spi_irq_subscribe(self);

	status = cw1200_core_probe(&cw1200_spi_hwbus_ops,
				   self, &func->dev, &self->core,
				   self->pdata->ref_clk,
				   self->pdata->macaddr,
				   self->pdata->sdd_file,
				   self->pdata->have_5ghz);

	if (status) {
		cw1200_spi_irq_unsubscribe(self);
		cw1200_spi_off(plat_data);
	}

	return status;
}

/* Disconnect Function to be called by SPI stack when device is disconnected */
static int cw1200_spi_disconnect(struct spi_device *func)
{
	struct hwbus_priv *self = spi_get_drvdata(func);

	if (self) {
		cw1200_spi_irq_unsubscribe(self);
		if (self->core) {
			cw1200_core_release(self->core);
			self->core = NULL;
		}
	}
	cw1200_spi_off(dev_get_platdata(&func->dev));

	return 0;
}

#ifdef CONFIG_PM
static int cw1200_spi_suspend(struct device *dev)
{
	struct hwbus_priv *self = spi_get_drvdata(to_spi_device(dev));

	if (!cw1200_can_suspend(self->core))
		return -EAGAIN;

	/* XXX notify host that we have to keep CW1200 powered on? */
	return 0;
}

static SIMPLE_DEV_PM_OPS(cw1200_pm_ops, cw1200_spi_suspend, NULL);

#endif

static struct spi_driver spi_driver = {
	.probe		= cw1200_spi_probe,
	.remove		= cw1200_spi_disconnect,
	.driver = {
		.name		= "cw1200_wlan_spi",
		.bus            = &spi_bus_type,
		.owner          = THIS_MODULE,
#ifdef CONFIG_PM
		.pm		= &cw1200_pm_ops,
#endif
	},
};

module_spi_driver(spi_driver);