xref: /openbmc/linux/drivers/net/ieee802154/cc2520.c (revision 4f3db074)
1 /* Driver for TI CC2520 802.15.4 Wireless-PAN Networking controller
2  *
3  * Copyright (C) 2014 Varka Bhadram <varkab@cdac.in>
4  *		      Md.Jamal Mohiuddin <mjmohiuddin@cdac.in>
5  *		      P Sowjanya <sowjanyap@cdac.in>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  */
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/gpio.h>
16 #include <linux/delay.h>
17 #include <linux/spi/spi.h>
18 #include <linux/spi/cc2520.h>
19 #include <linux/workqueue.h>
20 #include <linux/interrupt.h>
21 #include <linux/skbuff.h>
22 #include <linux/of_gpio.h>
23 #include <linux/ieee802154.h>
24 
25 #include <net/mac802154.h>
26 #include <net/cfg802154.h>
27 
28 #define	SPI_COMMAND_BUFFER	3
29 #define	HIGH			1
30 #define	LOW			0
31 #define	STATE_IDLE		0
32 #define	RSSI_VALID		0
33 #define	RSSI_OFFSET		78
34 
35 #define	CC2520_RAM_SIZE		640
36 #define	CC2520_FIFO_SIZE	128
37 
38 #define	CC2520RAM_TXFIFO	0x100
39 #define	CC2520RAM_RXFIFO	0x180
40 #define	CC2520RAM_IEEEADDR	0x3EA
41 #define	CC2520RAM_PANID		0x3F2
42 #define	CC2520RAM_SHORTADDR	0x3F4
43 
44 #define	CC2520_FREG_MASK	0x3F
45 
46 /* status byte values */
47 #define	CC2520_STATUS_XOSC32M_STABLE	BIT(7)
48 #define	CC2520_STATUS_RSSI_VALID	BIT(6)
49 #define	CC2520_STATUS_TX_UNDERFLOW	BIT(3)
50 
51 /* IEEE-802.15.4 defined constants (2.4 GHz logical channels) */
52 #define	CC2520_MINCHANNEL		11
53 #define	CC2520_MAXCHANNEL		26
54 #define	CC2520_CHANNEL_SPACING		5
55 
56 /* command strobes */
57 #define	CC2520_CMD_SNOP			0x00
58 #define	CC2520_CMD_IBUFLD		0x02
59 #define	CC2520_CMD_SIBUFEX		0x03
60 #define	CC2520_CMD_SSAMPLECCA		0x04
61 #define	CC2520_CMD_SRES			0x0f
62 #define	CC2520_CMD_MEMORY_MASK		0x0f
63 #define	CC2520_CMD_MEMORY_READ		0x10
64 #define	CC2520_CMD_MEMORY_WRITE		0x20
65 #define	CC2520_CMD_RXBUF		0x30
66 #define	CC2520_CMD_RXBUFCP		0x38
67 #define	CC2520_CMD_RXBUFMOV		0x32
68 #define	CC2520_CMD_TXBUF		0x3A
69 #define	CC2520_CMD_TXBUFCP		0x3E
70 #define	CC2520_CMD_RANDOM		0x3C
71 #define	CC2520_CMD_SXOSCON		0x40
72 #define	CC2520_CMD_STXCAL		0x41
73 #define	CC2520_CMD_SRXON		0x42
74 #define	CC2520_CMD_STXON		0x43
75 #define	CC2520_CMD_STXONCCA		0x44
76 #define	CC2520_CMD_SRFOFF		0x45
77 #define	CC2520_CMD_SXOSCOFF		0x46
78 #define	CC2520_CMD_SFLUSHRX		0x47
79 #define	CC2520_CMD_SFLUSHTX		0x48
80 #define	CC2520_CMD_SACK			0x49
81 #define	CC2520_CMD_SACKPEND		0x4A
82 #define	CC2520_CMD_SNACK		0x4B
83 #define	CC2520_CMD_SRXMASKBITSET	0x4C
84 #define	CC2520_CMD_SRXMASKBITCLR	0x4D
85 #define	CC2520_CMD_RXMASKAND		0x4E
86 #define	CC2520_CMD_RXMASKOR		0x4F
87 #define	CC2520_CMD_MEMCP		0x50
88 #define	CC2520_CMD_MEMCPR		0x52
89 #define	CC2520_CMD_MEMXCP		0x54
90 #define	CC2520_CMD_MEMXWR		0x56
91 #define	CC2520_CMD_BCLR			0x58
92 #define	CC2520_CMD_BSET			0x59
93 #define	CC2520_CMD_CTR_UCTR		0x60
94 #define	CC2520_CMD_CBCMAC		0x64
95 #define	CC2520_CMD_UCBCMAC		0x66
96 #define	CC2520_CMD_CCM			0x68
97 #define	CC2520_CMD_UCCM			0x6A
98 #define	CC2520_CMD_ECB			0x70
99 #define	CC2520_CMD_ECBO			0x72
100 #define	CC2520_CMD_ECBX			0x74
101 #define	CC2520_CMD_INC			0x78
102 #define	CC2520_CMD_ABORT		0x7F
103 #define	CC2520_CMD_REGISTER_READ	0x80
104 #define	CC2520_CMD_REGISTER_WRITE	0xC0
105 
106 /* status registers */
107 #define	CC2520_CHIPID			0x40
108 #define	CC2520_VERSION			0x42
109 #define	CC2520_EXTCLOCK			0x44
110 #define	CC2520_MDMCTRL0			0x46
111 #define	CC2520_MDMCTRL1			0x47
112 #define	CC2520_FREQEST			0x48
113 #define	CC2520_RXCTRL			0x4A
114 #define	CC2520_FSCTRL			0x4C
115 #define	CC2520_FSCAL0			0x4E
116 #define	CC2520_FSCAL1			0x4F
117 #define	CC2520_FSCAL2			0x50
118 #define	CC2520_FSCAL3			0x51
119 #define	CC2520_AGCCTRL0			0x52
120 #define	CC2520_AGCCTRL1			0x53
121 #define	CC2520_AGCCTRL2			0x54
122 #define	CC2520_AGCCTRL3			0x55
123 #define	CC2520_ADCTEST0			0x56
124 #define	CC2520_ADCTEST1			0x57
125 #define	CC2520_ADCTEST2			0x58
126 #define	CC2520_MDMTEST0			0x5A
127 #define	CC2520_MDMTEST1			0x5B
128 #define	CC2520_DACTEST0			0x5C
129 #define	CC2520_DACTEST1			0x5D
130 #define	CC2520_ATEST			0x5E
131 #define	CC2520_DACTEST2			0x5F
132 #define	CC2520_PTEST0			0x60
133 #define	CC2520_PTEST1			0x61
134 #define	CC2520_RESERVED			0x62
135 #define	CC2520_DPUBIST			0x7A
136 #define	CC2520_ACTBIST			0x7C
137 #define	CC2520_RAMBIST			0x7E
138 
139 /* frame registers */
140 #define	CC2520_FRMFILT0			0x00
141 #define	CC2520_FRMFILT1			0x01
142 #define	CC2520_SRCMATCH			0x02
143 #define	CC2520_SRCSHORTEN0		0x04
144 #define	CC2520_SRCSHORTEN1		0x05
145 #define	CC2520_SRCSHORTEN2		0x06
146 #define	CC2520_SRCEXTEN0		0x08
147 #define	CC2520_SRCEXTEN1		0x09
148 #define	CC2520_SRCEXTEN2		0x0A
149 #define	CC2520_FRMCTRL0			0x0C
150 #define	CC2520_FRMCTRL1			0x0D
151 #define	CC2520_RXENABLE0		0x0E
152 #define	CC2520_RXENABLE1		0x0F
153 #define	CC2520_EXCFLAG0			0x10
154 #define	CC2520_EXCFLAG1			0x11
155 #define	CC2520_EXCFLAG2			0x12
156 #define	CC2520_EXCMASKA0		0x14
157 #define	CC2520_EXCMASKA1		0x15
158 #define	CC2520_EXCMASKA2		0x16
159 #define	CC2520_EXCMASKB0		0x18
160 #define	CC2520_EXCMASKB1		0x19
161 #define	CC2520_EXCMASKB2		0x1A
162 #define	CC2520_EXCBINDX0		0x1C
163 #define	CC2520_EXCBINDX1		0x1D
164 #define	CC2520_EXCBINDY0		0x1E
165 #define	CC2520_EXCBINDY1		0x1F
166 #define	CC2520_GPIOCTRL0		0x20
167 #define	CC2520_GPIOCTRL1		0x21
168 #define	CC2520_GPIOCTRL2		0x22
169 #define	CC2520_GPIOCTRL3		0x23
170 #define	CC2520_GPIOCTRL4		0x24
171 #define	CC2520_GPIOCTRL5		0x25
172 #define	CC2520_GPIOPOLARITY		0x26
173 #define	CC2520_GPIOCTRL			0x28
174 #define	CC2520_DPUCON			0x2A
175 #define	CC2520_DPUSTAT			0x2C
176 #define	CC2520_FREQCTRL			0x2E
177 #define	CC2520_FREQTUNE			0x2F
178 #define	CC2520_TXPOWER			0x30
179 #define	CC2520_TXCTRL			0x31
180 #define	CC2520_FSMSTAT0			0x32
181 #define	CC2520_FSMSTAT1			0x33
182 #define	CC2520_FIFOPCTRL		0x34
183 #define	CC2520_FSMCTRL			0x35
184 #define	CC2520_CCACTRL0			0x36
185 #define	CC2520_CCACTRL1			0x37
186 #define	CC2520_RSSI			0x38
187 #define	CC2520_RSSISTAT			0x39
188 #define	CC2520_RXFIRST			0x3C
189 #define	CC2520_RXFIFOCNT		0x3E
190 #define	CC2520_TXFIFOCNT		0x3F
191 
192 /* Driver private information */
193 struct cc2520_private {
194 	struct spi_device *spi;		/* SPI device structure */
195 	struct ieee802154_hw *hw;	/* IEEE-802.15.4 device */
196 	u8 *buf;			/* SPI TX/Rx data buffer */
197 	struct mutex buffer_mutex;	/* SPI buffer mutex */
198 	bool is_tx;			/* Flag for sync b/w Tx and Rx */
199 	int fifo_pin;			/* FIFO GPIO pin number */
200 	struct work_struct fifop_irqwork;/* Workqueue for FIFOP */
201 	spinlock_t lock;		/* Lock for is_tx*/
202 	struct completion tx_complete;	/* Work completion for Tx */
203 };
204 
205 /* Generic Functions */
206 static int
207 cc2520_cmd_strobe(struct cc2520_private *priv, u8 cmd)
208 {
209 	int ret;
210 	u8 status = 0xff;
211 	struct spi_message msg;
212 	struct spi_transfer xfer = {
213 		.len = 0,
214 		.tx_buf = priv->buf,
215 		.rx_buf = priv->buf,
216 	};
217 
218 	spi_message_init(&msg);
219 	spi_message_add_tail(&xfer, &msg);
220 
221 	mutex_lock(&priv->buffer_mutex);
222 	priv->buf[xfer.len++] = cmd;
223 	dev_vdbg(&priv->spi->dev,
224 		 "command strobe buf[0] = %02x\n",
225 		 priv->buf[0]);
226 
227 	ret = spi_sync(priv->spi, &msg);
228 	if (!ret)
229 		status = priv->buf[0];
230 	dev_vdbg(&priv->spi->dev,
231 		 "buf[0] = %02x\n", priv->buf[0]);
232 	mutex_unlock(&priv->buffer_mutex);
233 
234 	return ret;
235 }
236 
237 static int
238 cc2520_get_status(struct cc2520_private *priv, u8 *status)
239 {
240 	int ret;
241 	struct spi_message msg;
242 	struct spi_transfer xfer = {
243 		.len = 0,
244 		.tx_buf = priv->buf,
245 		.rx_buf = priv->buf,
246 	};
247 
248 	spi_message_init(&msg);
249 	spi_message_add_tail(&xfer, &msg);
250 
251 	mutex_lock(&priv->buffer_mutex);
252 	priv->buf[xfer.len++] = CC2520_CMD_SNOP;
253 	dev_vdbg(&priv->spi->dev,
254 		 "get status command buf[0] = %02x\n", priv->buf[0]);
255 
256 	ret = spi_sync(priv->spi, &msg);
257 	if (!ret)
258 		*status = priv->buf[0];
259 	dev_vdbg(&priv->spi->dev,
260 		 "buf[0] = %02x\n", priv->buf[0]);
261 	mutex_unlock(&priv->buffer_mutex);
262 
263 	return ret;
264 }
265 
266 static int
267 cc2520_write_register(struct cc2520_private *priv, u8 reg, u8 value)
268 {
269 	int status;
270 	struct spi_message msg;
271 	struct spi_transfer xfer = {
272 		.len = 0,
273 		.tx_buf = priv->buf,
274 		.rx_buf = priv->buf,
275 	};
276 
277 	spi_message_init(&msg);
278 	spi_message_add_tail(&xfer, &msg);
279 
280 	mutex_lock(&priv->buffer_mutex);
281 
282 	if (reg <= CC2520_FREG_MASK) {
283 		priv->buf[xfer.len++] = CC2520_CMD_REGISTER_WRITE | reg;
284 		priv->buf[xfer.len++] = value;
285 	} else {
286 		priv->buf[xfer.len++] = CC2520_CMD_MEMORY_WRITE;
287 		priv->buf[xfer.len++] = reg;
288 		priv->buf[xfer.len++] = value;
289 	}
290 	status = spi_sync(priv->spi, &msg);
291 	if (msg.status)
292 		status = msg.status;
293 
294 	mutex_unlock(&priv->buffer_mutex);
295 
296 	return status;
297 }
298 
299 static int
300 cc2520_write_ram(struct cc2520_private *priv, u16 reg, u8 len, u8 *data)
301 {
302 	int status;
303 	struct spi_message msg;
304 	struct spi_transfer xfer_head = {
305 		.len        = 0,
306 		.tx_buf        = priv->buf,
307 		.rx_buf        = priv->buf,
308 	};
309 
310 	struct spi_transfer xfer_buf = {
311 		.len = len,
312 		.tx_buf = data,
313 	};
314 
315 	mutex_lock(&priv->buffer_mutex);
316 	priv->buf[xfer_head.len++] = (CC2520_CMD_MEMORY_WRITE |
317 						((reg >> 8) & 0xff));
318 	priv->buf[xfer_head.len++] = reg & 0xff;
319 
320 	spi_message_init(&msg);
321 	spi_message_add_tail(&xfer_head, &msg);
322 	spi_message_add_tail(&xfer_buf, &msg);
323 
324 	status = spi_sync(priv->spi, &msg);
325 	dev_dbg(&priv->spi->dev, "spi status = %d\n", status);
326 	if (msg.status)
327 		status = msg.status;
328 
329 	mutex_unlock(&priv->buffer_mutex);
330 	return status;
331 }
332 
333 static int
334 cc2520_read_register(struct cc2520_private *priv, u8 reg, u8 *data)
335 {
336 	int status;
337 	struct spi_message msg;
338 	struct spi_transfer xfer1 = {
339 		.len = 0,
340 		.tx_buf = priv->buf,
341 		.rx_buf = priv->buf,
342 	};
343 
344 	struct spi_transfer xfer2 = {
345 		.len = 1,
346 		.rx_buf = data,
347 	};
348 
349 	spi_message_init(&msg);
350 	spi_message_add_tail(&xfer1, &msg);
351 	spi_message_add_tail(&xfer2, &msg);
352 
353 	mutex_lock(&priv->buffer_mutex);
354 	priv->buf[xfer1.len++] = CC2520_CMD_MEMORY_READ;
355 	priv->buf[xfer1.len++] = reg;
356 
357 	status = spi_sync(priv->spi, &msg);
358 	dev_dbg(&priv->spi->dev,
359 		"spi status = %d\n", status);
360 	if (msg.status)
361 		status = msg.status;
362 
363 	mutex_unlock(&priv->buffer_mutex);
364 
365 	return status;
366 }
367 
368 static int
369 cc2520_write_txfifo(struct cc2520_private *priv, u8 *data, u8 len)
370 {
371 	int status;
372 
373 	/* length byte must include FCS even
374 	 * if it is calculated in the hardware
375 	 */
376 	int len_byte = len + 2;
377 
378 	struct spi_message msg;
379 
380 	struct spi_transfer xfer_head = {
381 		.len = 0,
382 		.tx_buf = priv->buf,
383 		.rx_buf = priv->buf,
384 	};
385 	struct spi_transfer xfer_len = {
386 		.len = 1,
387 		.tx_buf = &len_byte,
388 	};
389 	struct spi_transfer xfer_buf = {
390 		.len = len,
391 		.tx_buf = data,
392 	};
393 
394 	spi_message_init(&msg);
395 	spi_message_add_tail(&xfer_head, &msg);
396 	spi_message_add_tail(&xfer_len, &msg);
397 	spi_message_add_tail(&xfer_buf, &msg);
398 
399 	mutex_lock(&priv->buffer_mutex);
400 	priv->buf[xfer_head.len++] = CC2520_CMD_TXBUF;
401 	dev_vdbg(&priv->spi->dev,
402 		 "TX_FIFO cmd buf[0] = %02x\n", priv->buf[0]);
403 
404 	status = spi_sync(priv->spi, &msg);
405 	dev_vdbg(&priv->spi->dev, "status = %d\n", status);
406 	if (msg.status)
407 		status = msg.status;
408 	dev_vdbg(&priv->spi->dev, "status = %d\n", status);
409 	dev_vdbg(&priv->spi->dev, "buf[0] = %02x\n", priv->buf[0]);
410 	mutex_unlock(&priv->buffer_mutex);
411 
412 	return status;
413 }
414 
415 static int
416 cc2520_read_rxfifo(struct cc2520_private *priv, u8 *data, u8 len, u8 *lqi)
417 {
418 	int status;
419 	struct spi_message msg;
420 
421 	struct spi_transfer xfer_head = {
422 		.len = 0,
423 		.tx_buf = priv->buf,
424 		.rx_buf = priv->buf,
425 	};
426 	struct spi_transfer xfer_buf = {
427 		.len = len,
428 		.rx_buf = data,
429 	};
430 
431 	spi_message_init(&msg);
432 	spi_message_add_tail(&xfer_head, &msg);
433 	spi_message_add_tail(&xfer_buf, &msg);
434 
435 	mutex_lock(&priv->buffer_mutex);
436 	priv->buf[xfer_head.len++] = CC2520_CMD_RXBUF;
437 
438 	dev_vdbg(&priv->spi->dev, "read rxfifo buf[0] = %02x\n", priv->buf[0]);
439 	dev_vdbg(&priv->spi->dev, "buf[1] = %02x\n", priv->buf[1]);
440 
441 	status = spi_sync(priv->spi, &msg);
442 	dev_vdbg(&priv->spi->dev, "status = %d\n", status);
443 	if (msg.status)
444 		status = msg.status;
445 	dev_vdbg(&priv->spi->dev, "status = %d\n", status);
446 	dev_vdbg(&priv->spi->dev,
447 		 "return status buf[0] = %02x\n", priv->buf[0]);
448 	dev_vdbg(&priv->spi->dev, "length buf[1] = %02x\n", priv->buf[1]);
449 
450 	mutex_unlock(&priv->buffer_mutex);
451 
452 	return status;
453 }
454 
455 static int cc2520_start(struct ieee802154_hw *hw)
456 {
457 	return cc2520_cmd_strobe(hw->priv, CC2520_CMD_SRXON);
458 }
459 
460 static void cc2520_stop(struct ieee802154_hw *hw)
461 {
462 	cc2520_cmd_strobe(hw->priv, CC2520_CMD_SRFOFF);
463 }
464 
465 static int
466 cc2520_tx(struct ieee802154_hw *hw, struct sk_buff *skb)
467 {
468 	struct cc2520_private *priv = hw->priv;
469 	unsigned long flags;
470 	int rc;
471 	u8 status = 0;
472 
473 	rc = cc2520_cmd_strobe(priv, CC2520_CMD_SFLUSHTX);
474 	if (rc)
475 		goto err_tx;
476 
477 	rc = cc2520_write_txfifo(priv, skb->data, skb->len);
478 	if (rc)
479 		goto err_tx;
480 
481 	rc = cc2520_get_status(priv, &status);
482 	if (rc)
483 		goto err_tx;
484 
485 	if (status & CC2520_STATUS_TX_UNDERFLOW) {
486 		dev_err(&priv->spi->dev, "cc2520 tx underflow exception\n");
487 		goto err_tx;
488 	}
489 
490 	spin_lock_irqsave(&priv->lock, flags);
491 	BUG_ON(priv->is_tx);
492 	priv->is_tx = 1;
493 	spin_unlock_irqrestore(&priv->lock, flags);
494 
495 	rc = cc2520_cmd_strobe(priv, CC2520_CMD_STXONCCA);
496 	if (rc)
497 		goto err;
498 
499 	rc = wait_for_completion_interruptible(&priv->tx_complete);
500 	if (rc < 0)
501 		goto err;
502 
503 	cc2520_cmd_strobe(priv, CC2520_CMD_SFLUSHTX);
504 	cc2520_cmd_strobe(priv, CC2520_CMD_SRXON);
505 
506 	return rc;
507 err:
508 	spin_lock_irqsave(&priv->lock, flags);
509 	priv->is_tx = 0;
510 	spin_unlock_irqrestore(&priv->lock, flags);
511 err_tx:
512 	return rc;
513 }
514 
515 static int cc2520_rx(struct cc2520_private *priv)
516 {
517 	u8 len = 0, lqi = 0, bytes = 1;
518 	struct sk_buff *skb;
519 
520 	cc2520_read_rxfifo(priv, &len, bytes, &lqi);
521 
522 	if (len < 2 || len > IEEE802154_MTU)
523 		return -EINVAL;
524 
525 	skb = dev_alloc_skb(len);
526 	if (!skb)
527 		return -ENOMEM;
528 
529 	if (cc2520_read_rxfifo(priv, skb_put(skb, len), len, &lqi)) {
530 		dev_dbg(&priv->spi->dev, "frame reception failed\n");
531 		kfree_skb(skb);
532 		return -EINVAL;
533 	}
534 
535 	skb_trim(skb, skb->len - 2);
536 
537 	ieee802154_rx_irqsafe(priv->hw, skb, lqi);
538 
539 	dev_vdbg(&priv->spi->dev, "RXFIFO: %x %x\n", len, lqi);
540 
541 	return 0;
542 }
543 
544 static int
545 cc2520_ed(struct ieee802154_hw *hw, u8 *level)
546 {
547 	struct cc2520_private *priv = hw->priv;
548 	u8 status = 0xff;
549 	u8 rssi;
550 	int ret;
551 
552 	ret = cc2520_read_register(priv, CC2520_RSSISTAT, &status);
553 	if (ret)
554 		return ret;
555 
556 	if (status != RSSI_VALID)
557 		return -EINVAL;
558 
559 	ret = cc2520_read_register(priv, CC2520_RSSI, &rssi);
560 	if (ret)
561 		return ret;
562 
563 	/* level = RSSI(rssi) - OFFSET [dBm] : offset is 76dBm */
564 	*level = rssi - RSSI_OFFSET;
565 
566 	return 0;
567 }
568 
569 static int
570 cc2520_set_channel(struct ieee802154_hw *hw, u8 page, u8 channel)
571 {
572 	struct cc2520_private *priv = hw->priv;
573 	int ret;
574 
575 	dev_dbg(&priv->spi->dev, "trying to set channel\n");
576 
577 	BUG_ON(page != 0);
578 	BUG_ON(channel < CC2520_MINCHANNEL);
579 	BUG_ON(channel > CC2520_MAXCHANNEL);
580 
581 	ret = cc2520_write_register(priv, CC2520_FREQCTRL,
582 				    11 + 5*(channel - 11));
583 
584 	return ret;
585 }
586 
587 static int
588 cc2520_filter(struct ieee802154_hw *hw,
589 	      struct ieee802154_hw_addr_filt *filt, unsigned long changed)
590 {
591 	struct cc2520_private *priv = hw->priv;
592 
593 	if (changed & IEEE802154_AFILT_PANID_CHANGED) {
594 		u16 panid = le16_to_cpu(filt->pan_id);
595 
596 		dev_vdbg(&priv->spi->dev,
597 			 "cc2520_filter called for pan id\n");
598 		cc2520_write_ram(priv, CC2520RAM_PANID,
599 				 sizeof(panid), (u8 *)&panid);
600 	}
601 
602 	if (changed & IEEE802154_AFILT_IEEEADDR_CHANGED) {
603 		dev_vdbg(&priv->spi->dev,
604 			 "cc2520_filter called for IEEE addr\n");
605 		cc2520_write_ram(priv, CC2520RAM_IEEEADDR,
606 				 sizeof(filt->ieee_addr),
607 				 (u8 *)&filt->ieee_addr);
608 	}
609 
610 	if (changed & IEEE802154_AFILT_SADDR_CHANGED) {
611 		u16 addr = le16_to_cpu(filt->short_addr);
612 
613 		dev_vdbg(&priv->spi->dev,
614 			 "cc2520_filter called for saddr\n");
615 		cc2520_write_ram(priv, CC2520RAM_SHORTADDR,
616 				 sizeof(addr), (u8 *)&addr);
617 	}
618 
619 	if (changed & IEEE802154_AFILT_PANC_CHANGED) {
620 		dev_vdbg(&priv->spi->dev,
621 			 "cc2520_filter called for panc change\n");
622 		if (filt->pan_coord)
623 			cc2520_write_register(priv, CC2520_FRMFILT0, 0x02);
624 		else
625 			cc2520_write_register(priv, CC2520_FRMFILT0, 0x00);
626 	}
627 
628 	return 0;
629 }
630 
631 static const struct ieee802154_ops cc2520_ops = {
632 	.owner = THIS_MODULE,
633 	.start = cc2520_start,
634 	.stop = cc2520_stop,
635 	.xmit_sync = cc2520_tx,
636 	.ed = cc2520_ed,
637 	.set_channel = cc2520_set_channel,
638 	.set_hw_addr_filt = cc2520_filter,
639 };
640 
641 static int cc2520_register(struct cc2520_private *priv)
642 {
643 	int ret = -ENOMEM;
644 
645 	priv->hw = ieee802154_alloc_hw(sizeof(*priv), &cc2520_ops);
646 	if (!priv->hw)
647 		goto err_ret;
648 
649 	priv->hw->priv = priv;
650 	priv->hw->parent = &priv->spi->dev;
651 	priv->hw->extra_tx_headroom = 0;
652 	priv->hw->vif_data_size = sizeof(*priv);
653 	ieee802154_random_extended_addr(&priv->hw->phy->perm_extended_addr);
654 
655 	/* We do support only 2.4 Ghz */
656 	priv->hw->phy->channels_supported[0] = 0x7FFF800;
657 	priv->hw->flags = IEEE802154_HW_OMIT_CKSUM | IEEE802154_HW_AACK |
658 			  IEEE802154_HW_AFILT;
659 
660 	dev_vdbg(&priv->spi->dev, "registered cc2520\n");
661 	ret = ieee802154_register_hw(priv->hw);
662 	if (ret)
663 		goto err_free_device;
664 
665 	return 0;
666 
667 err_free_device:
668 	ieee802154_free_hw(priv->hw);
669 err_ret:
670 	return ret;
671 }
672 
673 static void cc2520_fifop_irqwork(struct work_struct *work)
674 {
675 	struct cc2520_private *priv
676 		= container_of(work, struct cc2520_private, fifop_irqwork);
677 
678 	dev_dbg(&priv->spi->dev, "fifop interrupt received\n");
679 
680 	if (gpio_get_value(priv->fifo_pin))
681 		cc2520_rx(priv);
682 	else
683 		dev_dbg(&priv->spi->dev, "rxfifo overflow\n");
684 
685 	cc2520_cmd_strobe(priv, CC2520_CMD_SFLUSHRX);
686 	cc2520_cmd_strobe(priv, CC2520_CMD_SFLUSHRX);
687 }
688 
689 static irqreturn_t cc2520_fifop_isr(int irq, void *data)
690 {
691 	struct cc2520_private *priv = data;
692 
693 	schedule_work(&priv->fifop_irqwork);
694 
695 	return IRQ_HANDLED;
696 }
697 
698 static irqreturn_t cc2520_sfd_isr(int irq, void *data)
699 {
700 	struct cc2520_private *priv = data;
701 	unsigned long flags;
702 
703 	spin_lock_irqsave(&priv->lock, flags);
704 	if (priv->is_tx) {
705 		priv->is_tx = 0;
706 		spin_unlock_irqrestore(&priv->lock, flags);
707 		dev_dbg(&priv->spi->dev, "SFD for TX\n");
708 		complete(&priv->tx_complete);
709 	} else {
710 		spin_unlock_irqrestore(&priv->lock, flags);
711 		dev_dbg(&priv->spi->dev, "SFD for RX\n");
712 	}
713 
714 	return IRQ_HANDLED;
715 }
716 
717 static int cc2520_get_platform_data(struct spi_device *spi,
718 				    struct cc2520_platform_data *pdata)
719 {
720 	struct device_node *np = spi->dev.of_node;
721 	struct cc2520_private *priv = spi_get_drvdata(spi);
722 
723 	if (!np) {
724 		struct cc2520_platform_data *spi_pdata = spi->dev.platform_data;
725 		if (!spi_pdata)
726 			return -ENOENT;
727 		*pdata = *spi_pdata;
728 		return 0;
729 	}
730 
731 	pdata->fifo = of_get_named_gpio(np, "fifo-gpio", 0);
732 	priv->fifo_pin = pdata->fifo;
733 
734 	pdata->fifop = of_get_named_gpio(np, "fifop-gpio", 0);
735 
736 	pdata->sfd = of_get_named_gpio(np, "sfd-gpio", 0);
737 	pdata->cca = of_get_named_gpio(np, "cca-gpio", 0);
738 	pdata->vreg = of_get_named_gpio(np, "vreg-gpio", 0);
739 	pdata->reset = of_get_named_gpio(np, "reset-gpio", 0);
740 
741 	pdata->amplified = of_property_read_bool(np, "amplified");
742 
743 	return 0;
744 }
745 
746 static int cc2520_hw_init(struct cc2520_private *priv)
747 {
748 	u8 status = 0, state = 0xff;
749 	int ret;
750 	int timeout = 100;
751 	struct cc2520_platform_data pdata;
752 
753 	ret = cc2520_get_platform_data(priv->spi, &pdata);
754 	if (ret)
755 		goto err_ret;
756 
757 	ret = cc2520_read_register(priv, CC2520_FSMSTAT1, &state);
758 	if (ret)
759 		goto err_ret;
760 
761 	if (state != STATE_IDLE)
762 		return -EINVAL;
763 
764 	do {
765 		ret = cc2520_get_status(priv, &status);
766 		if (ret)
767 			goto err_ret;
768 
769 		if (timeout-- <= 0) {
770 			dev_err(&priv->spi->dev, "oscillator start failed!\n");
771 			return ret;
772 		}
773 		udelay(1);
774 	} while (!(status & CC2520_STATUS_XOSC32M_STABLE));
775 
776 	dev_vdbg(&priv->spi->dev, "oscillator brought up\n");
777 
778 	/* If the CC2520 is connected to a CC2591 amplifier, we must both
779 	 * configure GPIOs on the CC2520 to correctly configure the CC2591
780 	 * and change a couple settings of the CC2520 to work with the
781 	 * amplifier. See section 8 page 17 of TI application note AN065.
782 	 * http://www.ti.com/lit/an/swra229a/swra229a.pdf
783 	 */
784 	if (pdata.amplified) {
785 		ret = cc2520_write_register(priv, CC2520_TXPOWER, 0xF9);
786 		if (ret)
787 			goto err_ret;
788 
789 		ret = cc2520_write_register(priv, CC2520_AGCCTRL1, 0x16);
790 		if (ret)
791 			goto err_ret;
792 
793 		ret = cc2520_write_register(priv, CC2520_GPIOCTRL0, 0x46);
794 		if (ret)
795 			goto err_ret;
796 
797 		ret = cc2520_write_register(priv, CC2520_GPIOCTRL5, 0x47);
798 		if (ret)
799 			goto err_ret;
800 
801 		ret = cc2520_write_register(priv, CC2520_GPIOPOLARITY, 0x1e);
802 		if (ret)
803 			goto err_ret;
804 
805 		ret = cc2520_write_register(priv, CC2520_TXCTRL, 0xc1);
806 		if (ret)
807 			goto err_ret;
808 	} else {
809 		ret = cc2520_write_register(priv, CC2520_TXPOWER, 0xF7);
810 		if (ret)
811 			goto err_ret;
812 
813 		ret = cc2520_write_register(priv, CC2520_AGCCTRL1, 0x11);
814 		if (ret)
815 			goto err_ret;
816 	}
817 
818 	/* Registers default value: section 28.1 in Datasheet */
819 	ret = cc2520_write_register(priv, CC2520_CCACTRL0, 0x1A);
820 	if (ret)
821 		goto err_ret;
822 
823 	ret = cc2520_write_register(priv, CC2520_MDMCTRL0, 0x85);
824 	if (ret)
825 		goto err_ret;
826 
827 	ret = cc2520_write_register(priv, CC2520_MDMCTRL1, 0x14);
828 	if (ret)
829 		goto err_ret;
830 
831 	ret = cc2520_write_register(priv, CC2520_RXCTRL, 0x3f);
832 	if (ret)
833 		goto err_ret;
834 
835 	ret = cc2520_write_register(priv, CC2520_FSCTRL, 0x5a);
836 	if (ret)
837 		goto err_ret;
838 
839 	ret = cc2520_write_register(priv, CC2520_FSCAL1, 0x2b);
840 	if (ret)
841 		goto err_ret;
842 
843 	ret = cc2520_write_register(priv, CC2520_ADCTEST0, 0x10);
844 	if (ret)
845 		goto err_ret;
846 
847 	ret = cc2520_write_register(priv, CC2520_ADCTEST1, 0x0e);
848 	if (ret)
849 		goto err_ret;
850 
851 	ret = cc2520_write_register(priv, CC2520_ADCTEST2, 0x03);
852 	if (ret)
853 		goto err_ret;
854 
855 	ret = cc2520_write_register(priv, CC2520_FRMCTRL0, 0x60);
856 	if (ret)
857 		goto err_ret;
858 
859 	ret = cc2520_write_register(priv, CC2520_FRMCTRL1, 0x03);
860 	if (ret)
861 		goto err_ret;
862 
863 	ret = cc2520_write_register(priv, CC2520_FRMFILT0, 0x00);
864 	if (ret)
865 		goto err_ret;
866 
867 	ret = cc2520_write_register(priv, CC2520_FIFOPCTRL, 127);
868 	if (ret)
869 		goto err_ret;
870 
871 	return 0;
872 
873 err_ret:
874 	return ret;
875 }
876 
877 static int cc2520_probe(struct spi_device *spi)
878 {
879 	struct cc2520_private *priv;
880 	struct cc2520_platform_data pdata;
881 	int ret;
882 
883 	priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL);
884 	if (!priv)
885 		return -ENOMEM;
886 
887 	spi_set_drvdata(spi, priv);
888 
889 	ret = cc2520_get_platform_data(spi, &pdata);
890 	if (ret < 0) {
891 		dev_err(&spi->dev, "no platform data\n");
892 		return -EINVAL;
893 	}
894 
895 	priv->spi = spi;
896 
897 	priv->buf = devm_kzalloc(&spi->dev,
898 				 SPI_COMMAND_BUFFER, GFP_KERNEL);
899 	if (!priv->buf)
900 		return -ENOMEM;
901 
902 	mutex_init(&priv->buffer_mutex);
903 	INIT_WORK(&priv->fifop_irqwork, cc2520_fifop_irqwork);
904 	spin_lock_init(&priv->lock);
905 	init_completion(&priv->tx_complete);
906 
907 	/* Request all the gpio's */
908 	if (!gpio_is_valid(pdata.fifo)) {
909 		dev_err(&spi->dev, "fifo gpio is not valid\n");
910 		ret = -EINVAL;
911 		goto err_hw_init;
912 	}
913 
914 	ret = devm_gpio_request_one(&spi->dev, pdata.fifo,
915 				    GPIOF_IN, "fifo");
916 	if (ret)
917 		goto err_hw_init;
918 
919 	if (!gpio_is_valid(pdata.cca)) {
920 		dev_err(&spi->dev, "cca gpio is not valid\n");
921 		ret = -EINVAL;
922 		goto err_hw_init;
923 	}
924 
925 	ret = devm_gpio_request_one(&spi->dev, pdata.cca,
926 				    GPIOF_IN, "cca");
927 	if (ret)
928 		goto err_hw_init;
929 
930 	if (!gpio_is_valid(pdata.fifop)) {
931 		dev_err(&spi->dev, "fifop gpio is not valid\n");
932 		ret = -EINVAL;
933 		goto err_hw_init;
934 	}
935 
936 	ret = devm_gpio_request_one(&spi->dev, pdata.fifop,
937 				    GPIOF_IN, "fifop");
938 	if (ret)
939 		goto err_hw_init;
940 
941 	if (!gpio_is_valid(pdata.sfd)) {
942 		dev_err(&spi->dev, "sfd gpio is not valid\n");
943 		ret = -EINVAL;
944 		goto err_hw_init;
945 	}
946 
947 	ret = devm_gpio_request_one(&spi->dev, pdata.sfd,
948 				    GPIOF_IN, "sfd");
949 	if (ret)
950 		goto err_hw_init;
951 
952 	if (!gpio_is_valid(pdata.reset)) {
953 		dev_err(&spi->dev, "reset gpio is not valid\n");
954 		ret = -EINVAL;
955 		goto err_hw_init;
956 	}
957 
958 	ret = devm_gpio_request_one(&spi->dev, pdata.reset,
959 				    GPIOF_OUT_INIT_LOW, "reset");
960 	if (ret)
961 		goto err_hw_init;
962 
963 	if (!gpio_is_valid(pdata.vreg)) {
964 		dev_err(&spi->dev, "vreg gpio is not valid\n");
965 		ret = -EINVAL;
966 		goto err_hw_init;
967 	}
968 
969 	ret = devm_gpio_request_one(&spi->dev, pdata.vreg,
970 				    GPIOF_OUT_INIT_LOW, "vreg");
971 	if (ret)
972 		goto err_hw_init;
973 
974 	gpio_set_value(pdata.vreg, HIGH);
975 	usleep_range(100, 150);
976 
977 	gpio_set_value(pdata.reset, HIGH);
978 	usleep_range(200, 250);
979 
980 	ret = cc2520_hw_init(priv);
981 	if (ret)
982 		goto err_hw_init;
983 
984 	/* Set up fifop interrupt */
985 	ret = devm_request_irq(&spi->dev,
986 			       gpio_to_irq(pdata.fifop),
987 			       cc2520_fifop_isr,
988 			       IRQF_TRIGGER_RISING,
989 			       dev_name(&spi->dev),
990 			       priv);
991 	if (ret) {
992 		dev_err(&spi->dev, "could not get fifop irq\n");
993 		goto err_hw_init;
994 	}
995 
996 	/* Set up sfd interrupt */
997 	ret = devm_request_irq(&spi->dev,
998 			       gpio_to_irq(pdata.sfd),
999 			       cc2520_sfd_isr,
1000 			       IRQF_TRIGGER_FALLING,
1001 			       dev_name(&spi->dev),
1002 			       priv);
1003 	if (ret) {
1004 		dev_err(&spi->dev, "could not get sfd irq\n");
1005 		goto err_hw_init;
1006 	}
1007 
1008 	ret = cc2520_register(priv);
1009 	if (ret)
1010 		goto err_hw_init;
1011 
1012 	return 0;
1013 
1014 err_hw_init:
1015 	mutex_destroy(&priv->buffer_mutex);
1016 	flush_work(&priv->fifop_irqwork);
1017 	return ret;
1018 }
1019 
1020 static int cc2520_remove(struct spi_device *spi)
1021 {
1022 	struct cc2520_private *priv = spi_get_drvdata(spi);
1023 
1024 	mutex_destroy(&priv->buffer_mutex);
1025 	flush_work(&priv->fifop_irqwork);
1026 
1027 	ieee802154_unregister_hw(priv->hw);
1028 	ieee802154_free_hw(priv->hw);
1029 
1030 	return 0;
1031 }
1032 
1033 static const struct spi_device_id cc2520_ids[] = {
1034 	{"cc2520", },
1035 	{},
1036 };
1037 MODULE_DEVICE_TABLE(spi, cc2520_ids);
1038 
1039 static const struct of_device_id cc2520_of_ids[] = {
1040 	{.compatible = "ti,cc2520", },
1041 	{},
1042 };
1043 MODULE_DEVICE_TABLE(of, cc2520_of_ids);
1044 
1045 /* SPI driver structure */
1046 static struct spi_driver cc2520_driver = {
1047 	.driver = {
1048 		.name = "cc2520",
1049 		.bus = &spi_bus_type,
1050 		.owner = THIS_MODULE,
1051 		.of_match_table = of_match_ptr(cc2520_of_ids),
1052 	},
1053 	.id_table = cc2520_ids,
1054 	.probe = cc2520_probe,
1055 	.remove = cc2520_remove,
1056 };
1057 module_spi_driver(cc2520_driver);
1058 
1059 MODULE_AUTHOR("Varka Bhadram <varkab@cdac.in>");
1060 MODULE_DESCRIPTION("CC2520 Transceiver Driver");
1061 MODULE_LICENSE("GPL v2");
1062