1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *	linux/drivers/net/wireless/libertas/if_spi.c
4 *
5 *	Driver for Marvell SPI WLAN cards.
6 *
7 *	Copyright 2008 Analog Devices Inc.
8 *
9 *	Authors:
10 *	Andrey Yurovsky <andrey@cozybit.com>
11 *	Colin McCabe <colin@cozybit.com>
12 *
13 *	Inspired by if_sdio.c, Copyright 2007-2008 Pierre Ossman
14 */
15
16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18#include <linux/hardirq.h>
19#include <linux/interrupt.h>
20#include <linux/module.h>
21#include <linux/firmware.h>
22#include <linux/jiffies.h>
23#include <linux/list.h>
24#include <linux/netdevice.h>
25#include <linux/slab.h>
26#include <linux/spi/libertas_spi.h>
27#include <linux/spi/spi.h>
28
29#include "host.h"
30#include "decl.h"
31#include "defs.h"
32#include "dev.h"
33#include "if_spi.h"
34
35struct if_spi_packet {
36	struct list_head		list;
37	u16				blen;
38	u8				buffer[] __aligned(4);
39};
40
41struct if_spi_card {
42	struct spi_device		*spi;
43	struct lbs_private		*priv;
44	struct libertas_spi_platform_data *pdata;
45
46	/* The card ID and card revision, as reported by the hardware. */
47	u16				card_id;
48	u8				card_rev;
49
50	/* The last time that we initiated an SPU operation */
51	unsigned long			prev_xfer_time;
52
53	int				use_dummy_writes;
54	unsigned long			spu_port_delay;
55	unsigned long			spu_reg_delay;
56
57	/* Handles all SPI communication (except for FW load) */
58	struct workqueue_struct		*workqueue;
59	struct work_struct		packet_work;
60	struct work_struct		resume_work;
61
62	u8				cmd_buffer[IF_SPI_CMD_BUF_SIZE];
63
64	/* A buffer of incoming packets from libertas core.
65	 * Since we can't sleep in hw_host_to_card, we have to buffer
66	 * them. */
67	struct list_head		cmd_packet_list;
68	struct list_head		data_packet_list;
69
70	/* Protects cmd_packet_list and data_packet_list */
71	spinlock_t			buffer_lock;
72
73	/* True is card suspended */
74	u8				suspended;
75};
76
77static void free_if_spi_card(struct if_spi_card *card)
78{
79	struct if_spi_packet *packet, *tmp;
80
81	list_for_each_entry_safe(packet, tmp, &card->cmd_packet_list, list) {
82		list_del(&packet->list);
83		kfree(packet);
84	}
85	list_for_each_entry_safe(packet, tmp, &card->data_packet_list, list) {
86		list_del(&packet->list);
87		kfree(packet);
88	}
89	kfree(card);
90}
91
92#define MODEL_8385	0x04
93#define MODEL_8686	0x0b
94#define MODEL_8688	0x10
95
96static const struct lbs_fw_table fw_table[] = {
97	{ MODEL_8385, "libertas/gspi8385_helper.bin", "libertas/gspi8385.bin" },
98	{ MODEL_8385, "libertas/gspi8385_hlp.bin", "libertas/gspi8385.bin" },
99	{ MODEL_8686, "libertas/gspi8686_v9_helper.bin", "libertas/gspi8686_v9.bin" },
100	{ MODEL_8686, "libertas/gspi8686_hlp.bin", "libertas/gspi8686.bin" },
101	{ MODEL_8688, "libertas/gspi8688_helper.bin", "libertas/gspi8688.bin" },
102	{ 0, NULL, NULL }
103};
104MODULE_FIRMWARE("libertas/gspi8385_helper.bin");
105MODULE_FIRMWARE("libertas/gspi8385_hlp.bin");
106MODULE_FIRMWARE("libertas/gspi8385.bin");
107MODULE_FIRMWARE("libertas/gspi8686_v9_helper.bin");
108MODULE_FIRMWARE("libertas/gspi8686_v9.bin");
109MODULE_FIRMWARE("libertas/gspi8686_hlp.bin");
110MODULE_FIRMWARE("libertas/gspi8686.bin");
111MODULE_FIRMWARE("libertas/gspi8688_helper.bin");
112MODULE_FIRMWARE("libertas/gspi8688.bin");
113
114
115/*
116 * SPI Interface Unit Routines
117 *
118 * The SPU sits between the host and the WLAN module.
119 * All communication with the firmware is through SPU transactions.
120 *
121 * First we have to put a SPU register name on the bus. Then we can
122 * either read from or write to that register.
123 *
124 */
125
126static void spu_transaction_init(struct if_spi_card *card)
127{
128	if (!time_after(jiffies, card->prev_xfer_time + 1)) {
129		/* Unfortunately, the SPU requires a delay between successive
130		 * transactions. If our last transaction was more than a jiffy
131		 * ago, we have obviously already delayed enough.
132		 * If not, we have to busy-wait to be on the safe side. */
133		ndelay(400);
134	}
135}
136
137static void spu_transaction_finish(struct if_spi_card *card)
138{
139	card->prev_xfer_time = jiffies;
140}
141
142/*
143 * Write out a byte buffer to an SPI register,
144 * using a series of 16-bit transfers.
145 */
146static int spu_write(struct if_spi_card *card, u16 reg, const u8 *buf, int len)
147{
148	int err = 0;
149	__le16 reg_out = cpu_to_le16(reg | IF_SPI_WRITE_OPERATION_MASK);
150	struct spi_message m;
151	struct spi_transfer reg_trans;
152	struct spi_transfer data_trans;
153
154	spi_message_init(&m);
155	memset(&reg_trans, 0, sizeof(reg_trans));
156	memset(&data_trans, 0, sizeof(data_trans));
157
158	/* You must give an even number of bytes to the SPU, even if it
159	 * doesn't care about the last one.  */
160	BUG_ON(len & 0x1);
161
162	spu_transaction_init(card);
163
164	/* write SPU register index */
165	reg_trans.tx_buf = &reg_out;
166	reg_trans.len = sizeof(reg_out);
167
168	data_trans.tx_buf = buf;
169	data_trans.len = len;
170
171	spi_message_add_tail(&reg_trans, &m);
172	spi_message_add_tail(&data_trans, &m);
173
174	err = spi_sync(card->spi, &m);
175	spu_transaction_finish(card);
176	return err;
177}
178
179static inline int spu_write_u16(struct if_spi_card *card, u16 reg, u16 val)
180{
181	__le16 buff;
182
183	buff = cpu_to_le16(val);
184	return spu_write(card, reg, (u8 *)&buff, sizeof(u16));
185}
186
187static inline int spu_reg_is_port_reg(u16 reg)
188{
189	switch (reg) {
190	case IF_SPI_IO_RDWRPORT_REG:
191	case IF_SPI_CMD_RDWRPORT_REG:
192	case IF_SPI_DATA_RDWRPORT_REG:
193		return 1;
194	default:
195		return 0;
196	}
197}
198
199static int spu_read(struct if_spi_card *card, u16 reg, u8 *buf, int len)
200{
201	unsigned int delay;
202	int err = 0;
203	__le16 reg_out = cpu_to_le16(reg | IF_SPI_READ_OPERATION_MASK);
204	struct spi_message m;
205	struct spi_transfer reg_trans;
206	struct spi_transfer dummy_trans;
207	struct spi_transfer data_trans;
208
209	/*
210	 * You must take an even number of bytes from the SPU, even if you
211	 * don't care about the last one.
212	 */
213	BUG_ON(len & 0x1);
214
215	spu_transaction_init(card);
216
217	spi_message_init(&m);
218	memset(&reg_trans, 0, sizeof(reg_trans));
219	memset(&dummy_trans, 0, sizeof(dummy_trans));
220	memset(&data_trans, 0, sizeof(data_trans));
221
222	/* write SPU register index */
223	reg_trans.tx_buf = &reg_out;
224	reg_trans.len = sizeof(reg_out);
225	spi_message_add_tail(&reg_trans, &m);
226
227	delay = spu_reg_is_port_reg(reg) ? card->spu_port_delay :
228						card->spu_reg_delay;
229	if (card->use_dummy_writes) {
230		/* Clock in dummy cycles while the SPU fills the FIFO */
231		dummy_trans.len = delay / 8;
232		spi_message_add_tail(&dummy_trans, &m);
233	} else {
234		/* Busy-wait while the SPU fills the FIFO */
235		reg_trans.delay.value =
236			DIV_ROUND_UP((100 + (delay * 10)), 1000);
237		reg_trans.delay.unit = SPI_DELAY_UNIT_USECS;
238	}
239
240	/* read in data */
241	data_trans.rx_buf = buf;
242	data_trans.len = len;
243	spi_message_add_tail(&data_trans, &m);
244
245	err = spi_sync(card->spi, &m);
246	spu_transaction_finish(card);
247	return err;
248}
249
250/* Read 16 bits from an SPI register */
251static inline int spu_read_u16(struct if_spi_card *card, u16 reg, u16 *val)
252{
253	__le16 buf;
254	int ret;
255
256	ret = spu_read(card, reg, (u8 *)&buf, sizeof(buf));
257	if (ret == 0)
258		*val = le16_to_cpup(&buf);
259	return ret;
260}
261
262/*
263 * Read 32 bits from an SPI register.
264 * The low 16 bits are read first.
265 */
266static int spu_read_u32(struct if_spi_card *card, u16 reg, u32 *val)
267{
268	__le32 buf;
269	int err;
270
271	err = spu_read(card, reg, (u8 *)&buf, sizeof(buf));
272	if (!err)
273		*val = le32_to_cpup(&buf);
274	return err;
275}
276
277/*
278 * Keep reading 16 bits from an SPI register until you get the correct result.
279 *
280 * If mask = 0, the correct result is any non-zero number.
281 * If mask != 0, the correct result is any number where
282 * number & target_mask == target
283 *
284 * Returns -ETIMEDOUT if a second passes without the correct result.
285 */
286static int spu_wait_for_u16(struct if_spi_card *card, u16 reg,
287			u16 target_mask, u16 target)
288{
289	int err;
290	unsigned long timeout = jiffies + 5*HZ;
291	while (1) {
292		u16 val;
293		err = spu_read_u16(card, reg, &val);
294		if (err)
295			return err;
296		if (target_mask) {
297			if ((val & target_mask) == target)
298				return 0;
299		} else {
300			if (val)
301				return 0;
302		}
303		udelay(100);
304		if (time_after(jiffies, timeout)) {
305			pr_err("%s: timeout with val=%02x, target_mask=%02x, target=%02x\n",
306			       __func__, val, target_mask, target);
307			return -ETIMEDOUT;
308		}
309	}
310}
311
312/*
313 * Read 16 bits from an SPI register until you receive a specific value.
314 * Returns -ETIMEDOUT if a 4 tries pass without success.
315 */
316static int spu_wait_for_u32(struct if_spi_card *card, u32 reg, u32 target)
317{
318	int err, try;
319	for (try = 0; try < 4; ++try) {
320		u32 val = 0;
321		err = spu_read_u32(card, reg, &val);
322		if (err)
323			return err;
324		if (val == target)
325			return 0;
326		mdelay(100);
327	}
328	return -ETIMEDOUT;
329}
330
331static int spu_set_interrupt_mode(struct if_spi_card *card,
332			   int suppress_host_int,
333			   int auto_int)
334{
335	int err = 0;
336
337	/*
338	 * We can suppress a host interrupt by clearing the appropriate
339	 * bit in the "host interrupt status mask" register
340	 */
341	if (suppress_host_int) {
342		err = spu_write_u16(card, IF_SPI_HOST_INT_STATUS_MASK_REG, 0);
343		if (err)
344			return err;
345	} else {
346		err = spu_write_u16(card, IF_SPI_HOST_INT_STATUS_MASK_REG,
347			      IF_SPI_HISM_TX_DOWNLOAD_RDY |
348			      IF_SPI_HISM_RX_UPLOAD_RDY |
349			      IF_SPI_HISM_CMD_DOWNLOAD_RDY |
350			      IF_SPI_HISM_CARDEVENT |
351			      IF_SPI_HISM_CMD_UPLOAD_RDY);
352		if (err)
353			return err;
354	}
355
356	/*
357	 * If auto-interrupts are on, the completion of certain transactions
358	 * will trigger an interrupt automatically. If auto-interrupts
359	 * are off, we need to set the "Card Interrupt Cause" register to
360	 * trigger a card interrupt.
361	 */
362	if (auto_int) {
363		err = spu_write_u16(card, IF_SPI_HOST_INT_CTRL_REG,
364				IF_SPI_HICT_TX_DOWNLOAD_OVER_AUTO |
365				IF_SPI_HICT_RX_UPLOAD_OVER_AUTO |
366				IF_SPI_HICT_CMD_DOWNLOAD_OVER_AUTO |
367				IF_SPI_HICT_CMD_UPLOAD_OVER_AUTO);
368		if (err)
369			return err;
370	} else {
371		err = spu_write_u16(card, IF_SPI_HOST_INT_STATUS_MASK_REG, 0);
372		if (err)
373			return err;
374	}
375	return err;
376}
377
378static int spu_get_chip_revision(struct if_spi_card *card,
379				  u16 *card_id, u8 *card_rev)
380{
381	int err = 0;
382	u32 dev_ctrl;
383	err = spu_read_u32(card, IF_SPI_DEVICEID_CTRL_REG, &dev_ctrl);
384	if (err)
385		return err;
386	*card_id = IF_SPI_DEVICEID_CTRL_REG_TO_CARD_ID(dev_ctrl);
387	*card_rev = IF_SPI_DEVICEID_CTRL_REG_TO_CARD_REV(dev_ctrl);
388	return err;
389}
390
391static int spu_set_bus_mode(struct if_spi_card *card, u16 mode)
392{
393	int err = 0;
394	u16 rval;
395	/* set bus mode */
396	err = spu_write_u16(card, IF_SPI_SPU_BUS_MODE_REG, mode);
397	if (err)
398		return err;
399	/* Check that we were able to read back what we just wrote. */
400	err = spu_read_u16(card, IF_SPI_SPU_BUS_MODE_REG, &rval);
401	if (err)
402		return err;
403	if ((rval & 0xF) != mode) {
404		pr_err("Can't read bus mode register\n");
405		return -EIO;
406	}
407	return 0;
408}
409
410static int spu_init(struct if_spi_card *card, int use_dummy_writes)
411{
412	int err = 0;
413	u32 delay;
414
415	/*
416	 * We have to start up in timed delay mode so that we can safely
417	 * read the Delay Read Register.
418	 */
419	card->use_dummy_writes = 0;
420	err = spu_set_bus_mode(card,
421				IF_SPI_BUS_MODE_SPI_CLOCK_PHASE_RISING |
422				IF_SPI_BUS_MODE_DELAY_METHOD_TIMED |
423				IF_SPI_BUS_MODE_16_BIT_ADDRESS_16_BIT_DATA);
424	if (err)
425		return err;
426	card->spu_port_delay = 1000;
427	card->spu_reg_delay = 1000;
428	err = spu_read_u32(card, IF_SPI_DELAY_READ_REG, &delay);
429	if (err)
430		return err;
431	card->spu_port_delay = delay & 0x0000ffff;
432	card->spu_reg_delay = (delay & 0xffff0000) >> 16;
433
434	/* If dummy clock delay mode has been requested, switch to it now */
435	if (use_dummy_writes) {
436		card->use_dummy_writes = 1;
437		err = spu_set_bus_mode(card,
438				IF_SPI_BUS_MODE_SPI_CLOCK_PHASE_RISING |
439				IF_SPI_BUS_MODE_DELAY_METHOD_DUMMY_CLOCK |
440				IF_SPI_BUS_MODE_16_BIT_ADDRESS_16_BIT_DATA);
441		if (err)
442			return err;
443	}
444
445	lbs_deb_spi("Initialized SPU unit. "
446		    "spu_port_delay=0x%04lx, spu_reg_delay=0x%04lx\n",
447		    card->spu_port_delay, card->spu_reg_delay);
448	return err;
449}
450
451/*
452 * Firmware Loading
453 */
454
455static int if_spi_prog_helper_firmware(struct if_spi_card *card,
456					const struct firmware *firmware)
457{
458	int err = 0;
459	int bytes_remaining;
460	const u8 *fw;
461	u8 temp[HELPER_FW_LOAD_CHUNK_SZ];
462
463	err = spu_set_interrupt_mode(card, 1, 0);
464	if (err)
465		goto out;
466
467	bytes_remaining = firmware->size;
468	fw = firmware->data;
469
470	/* Load helper firmware image */
471	while (bytes_remaining > 0) {
472		/*
473		 * Scratch pad 1 should contain the number of bytes we
474		 * want to download to the firmware
475		 */
476		err = spu_write_u16(card, IF_SPI_SCRATCH_1_REG,
477					HELPER_FW_LOAD_CHUNK_SZ);
478		if (err)
479			goto out;
480
481		err = spu_wait_for_u16(card, IF_SPI_HOST_INT_STATUS_REG,
482					IF_SPI_HIST_CMD_DOWNLOAD_RDY,
483					IF_SPI_HIST_CMD_DOWNLOAD_RDY);
484		if (err)
485			goto out;
486
487		/*
488		 * Feed the data into the command read/write port reg
489		 * in chunks of 64 bytes
490		 */
491		memset(temp, 0, sizeof(temp));
492		memcpy(temp, fw,
493		       min(bytes_remaining, HELPER_FW_LOAD_CHUNK_SZ));
494		mdelay(10);
495		err = spu_write(card, IF_SPI_CMD_RDWRPORT_REG,
496					temp, HELPER_FW_LOAD_CHUNK_SZ);
497		if (err)
498			goto out;
499
500		/* Interrupt the boot code */
501		err = spu_write_u16(card, IF_SPI_HOST_INT_STATUS_REG, 0);
502		if (err)
503			goto out;
504		err = spu_write_u16(card, IF_SPI_CARD_INT_CAUSE_REG,
505				       IF_SPI_CIC_CMD_DOWNLOAD_OVER);
506		if (err)
507			goto out;
508		bytes_remaining -= HELPER_FW_LOAD_CHUNK_SZ;
509		fw += HELPER_FW_LOAD_CHUNK_SZ;
510	}
511
512	/*
513	 * Once the helper / single stage firmware download is complete,
514	 * write 0 to scratch pad 1 and interrupt the
515	 * bootloader. This completes the helper download.
516	 */
517	err = spu_write_u16(card, IF_SPI_SCRATCH_1_REG, FIRMWARE_DNLD_OK);
518	if (err)
519		goto out;
520	err = spu_write_u16(card, IF_SPI_HOST_INT_STATUS_REG, 0);
521	if (err)
522		goto out;
523	err = spu_write_u16(card, IF_SPI_CARD_INT_CAUSE_REG,
524				IF_SPI_CIC_CMD_DOWNLOAD_OVER);
525out:
526	if (err)
527		pr_err("failed to load helper firmware (err=%d)\n", err);
528
529	return err;
530}
531
532/*
533 * Returns the length of the next packet the firmware expects us to send.
534 * Sets crc_err if the previous transfer had a CRC error.
535 */
536static int if_spi_prog_main_firmware_check_len(struct if_spi_card *card,
537						int *crc_err)
538{
539	u16 len;
540	int err = 0;
541
542	/*
543	 * wait until the host interrupt status register indicates
544	 * that we are ready to download
545	 */
546	err = spu_wait_for_u16(card, IF_SPI_HOST_INT_STATUS_REG,
547				IF_SPI_HIST_CMD_DOWNLOAD_RDY,
548				IF_SPI_HIST_CMD_DOWNLOAD_RDY);
549	if (err) {
550		pr_err("timed out waiting for host_int_status\n");
551		return err;
552	}
553
554	/* Ask the device how many bytes of firmware it wants. */
555	err = spu_read_u16(card, IF_SPI_SCRATCH_1_REG, &len);
556	if (err)
557		return err;
558
559	if (len > IF_SPI_CMD_BUF_SIZE) {
560		pr_err("firmware load device requested a larger transfer than we are prepared to handle (len = %d)\n",
561		       len);
562		return -EIO;
563	}
564	if (len & 0x1) {
565		lbs_deb_spi("%s: crc error\n", __func__);
566		len &= ~0x1;
567		*crc_err = 1;
568	} else
569		*crc_err = 0;
570
571	return len;
572}
573
574static int if_spi_prog_main_firmware(struct if_spi_card *card,
575					const struct firmware *firmware)
576{
577	struct lbs_private *priv = card->priv;
578	int len, prev_len;
579	int bytes, crc_err = 0, err = 0;
580	const u8 *fw;
581	u16 num_crc_errs;
582
583	err = spu_set_interrupt_mode(card, 1, 0);
584	if (err)
585		goto out;
586
587	err = spu_wait_for_u16(card, IF_SPI_SCRATCH_1_REG, 0, 0);
588	if (err) {
589		netdev_err(priv->dev,
590			   "%s: timed out waiting for initial scratch reg = 0\n",
591			   __func__);
592		goto out;
593	}
594
595	num_crc_errs = 0;
596	prev_len = 0;
597	bytes = firmware->size;
598	fw = firmware->data;
599	while ((len = if_spi_prog_main_firmware_check_len(card, &crc_err))) {
600		if (len < 0) {
601			err = len;
602			goto out;
603		}
604		if (bytes < 0) {
605			/*
606			 * If there are no more bytes left, we would normally
607			 * expect to have terminated with len = 0
608			 */
609			netdev_err(priv->dev,
610				   "Firmware load wants more bytes than we have to offer.\n");
611			break;
612		}
613		if (crc_err) {
614			/* Previous transfer failed. */
615			if (++num_crc_errs > MAX_MAIN_FW_LOAD_CRC_ERR) {
616				pr_err("Too many CRC errors encountered in firmware load.\n");
617				err = -EIO;
618				goto out;
619			}
620		} else {
621			/* Previous transfer succeeded. Advance counters. */
622			bytes -= prev_len;
623			fw += prev_len;
624		}
625		if (bytes < len) {
626			memset(card->cmd_buffer, 0, len);
627			memcpy(card->cmd_buffer, fw, bytes);
628		} else
629			memcpy(card->cmd_buffer, fw, len);
630
631		err = spu_write_u16(card, IF_SPI_HOST_INT_STATUS_REG, 0);
632		if (err)
633			goto out;
634		err = spu_write(card, IF_SPI_CMD_RDWRPORT_REG,
635				card->cmd_buffer, len);
636		if (err)
637			goto out;
638		err = spu_write_u16(card, IF_SPI_CARD_INT_CAUSE_REG ,
639					IF_SPI_CIC_CMD_DOWNLOAD_OVER);
640		if (err)
641			goto out;
642		prev_len = len;
643	}
644	if (bytes > prev_len) {
645		pr_err("firmware load wants fewer bytes than we have to offer\n");
646	}
647
648	/* Confirm firmware download */
649	err = spu_wait_for_u32(card, IF_SPI_SCRATCH_4_REG,
650					SUCCESSFUL_FW_DOWNLOAD_MAGIC);
651	if (err) {
652		pr_err("failed to confirm the firmware download\n");
653		goto out;
654	}
655
656out:
657	if (err)
658		pr_err("failed to load firmware (err=%d)\n", err);
659
660	return err;
661}
662
663/*
664 * SPI Transfer Thread
665 *
666 * The SPI worker handles all SPI transfers, so there is no need for a lock.
667 */
668
669/* Move a command from the card to the host */
670static int if_spi_c2h_cmd(struct if_spi_card *card)
671{
672	struct lbs_private *priv = card->priv;
673	unsigned long flags;
674	int err = 0;
675	u16 len;
676	u8 i;
677
678	/*
679	 * We need a buffer big enough to handle whatever people send to
680	 * hw_host_to_card
681	 */
682	BUILD_BUG_ON(IF_SPI_CMD_BUF_SIZE < LBS_CMD_BUFFER_SIZE);
683	BUILD_BUG_ON(IF_SPI_CMD_BUF_SIZE < LBS_UPLD_SIZE);
684
685	/*
686	 * It's just annoying if the buffer size isn't a multiple of 4, because
687	 * then we might have len < IF_SPI_CMD_BUF_SIZE but
688	 * ALIGN(len, 4) > IF_SPI_CMD_BUF_SIZE
689	 */
690	BUILD_BUG_ON(IF_SPI_CMD_BUF_SIZE % 4 != 0);
691
692	/* How many bytes are there to read? */
693	err = spu_read_u16(card, IF_SPI_SCRATCH_2_REG, &len);
694	if (err)
695		goto out;
696	if (!len) {
697		netdev_err(priv->dev, "%s: error: card has no data for host\n",
698			   __func__);
699		err = -EINVAL;
700		goto out;
701	} else if (len > IF_SPI_CMD_BUF_SIZE) {
702		netdev_err(priv->dev,
703			   "%s: error: response packet too large: %d bytes, but maximum is %d\n",
704			   __func__, len, IF_SPI_CMD_BUF_SIZE);
705		err = -EINVAL;
706		goto out;
707	}
708
709	/* Read the data from the WLAN module into our command buffer */
710	err = spu_read(card, IF_SPI_CMD_RDWRPORT_REG,
711				card->cmd_buffer, ALIGN(len, 4));
712	if (err)
713		goto out;
714
715	spin_lock_irqsave(&priv->driver_lock, flags);
716	i = (priv->resp_idx == 0) ? 1 : 0;
717	BUG_ON(priv->resp_len[i]);
718	priv->resp_len[i] = len;
719	memcpy(priv->resp_buf[i], card->cmd_buffer, len);
720	lbs_notify_command_response(priv, i);
721	spin_unlock_irqrestore(&priv->driver_lock, flags);
722
723out:
724	if (err)
725		netdev_err(priv->dev, "%s: err=%d\n", __func__, err);
726
727	return err;
728}
729
730/* Move data from the card to the host */
731static int if_spi_c2h_data(struct if_spi_card *card)
732{
733	struct lbs_private *priv = card->priv;
734	struct sk_buff *skb;
735	char *data;
736	u16 len;
737	int err = 0;
738
739	/* How many bytes are there to read? */
740	err = spu_read_u16(card, IF_SPI_SCRATCH_1_REG, &len);
741	if (err)
742		goto out;
743	if (!len) {
744		netdev_err(priv->dev, "%s: error: card has no data for host\n",
745			   __func__);
746		err = -EINVAL;
747		goto out;
748	} else if (len > MRVDRV_ETH_RX_PACKET_BUFFER_SIZE) {
749		netdev_err(priv->dev,
750			   "%s: error: card has %d bytes of data, but our maximum skb size is %zu\n",
751			   __func__, len, MRVDRV_ETH_RX_PACKET_BUFFER_SIZE);
752		err = -EINVAL;
753		goto out;
754	}
755
756	/* TODO: should we allocate a smaller skb if we have less data? */
757	skb = dev_alloc_skb(MRVDRV_ETH_RX_PACKET_BUFFER_SIZE);
758	if (!skb) {
759		err = -ENOBUFS;
760		goto out;
761	}
762	skb_reserve(skb, IPFIELD_ALIGN_OFFSET);
763	data = skb_put(skb, len);
764
765	/* Read the data from the WLAN module into our skb... */
766	err = spu_read(card, IF_SPI_DATA_RDWRPORT_REG, data, ALIGN(len, 4));
767	if (err) {
768		dev_kfree_skb(skb);
769		goto out;
770	}
771
772	/* pass the SKB to libertas */
773	err = lbs_process_rxed_packet(card->priv, skb);
774	/* lbs_process_rxed_packet() consumes the skb */
775
776out:
777	if (err)
778		netdev_err(priv->dev, "%s: err=%d\n", __func__, err);
779
780	return err;
781}
782
783/* Move data or a command from the host to the card. */
784static void if_spi_h2c(struct if_spi_card *card,
785			struct if_spi_packet *packet, int type)
786{
787	struct lbs_private *priv = card->priv;
788	int err = 0;
789	u16 port_reg;
790
791	switch (type) {
792	case MVMS_DAT:
793		port_reg = IF_SPI_DATA_RDWRPORT_REG;
794		break;
795	case MVMS_CMD:
796		port_reg = IF_SPI_CMD_RDWRPORT_REG;
797		break;
798	default:
799		netdev_err(priv->dev, "can't transfer buffer of type %d\n",
800			   type);
801		err = -EINVAL;
802		goto out;
803	}
804
805	/* Write the data to the card */
806	err = spu_write(card, port_reg, packet->buffer, packet->blen);
807	if (err)
808		goto out;
809
810out:
811	kfree(packet);
812
813	if (err)
814		netdev_err(priv->dev, "%s: error %d\n", __func__, err);
815}
816
817/* Inform the host about a card event */
818static void if_spi_e2h(struct if_spi_card *card)
819{
820	int err = 0;
821	u32 cause;
822	struct lbs_private *priv = card->priv;
823
824	err = spu_read_u32(card, IF_SPI_SCRATCH_3_REG, &cause);
825	if (err)
826		goto out;
827
828	/* re-enable the card event interrupt */
829	err = spu_write_u16(card, IF_SPI_HOST_INT_STATUS_REG,
830			    ~IF_SPI_HICU_CARD_EVENT);
831	if (err)
832		goto out;
833
834	/* generate a card interrupt */
835	err = spu_write_u16(card, IF_SPI_CARD_INT_CAUSE_REG,
836			    IF_SPI_CIC_HOST_EVENT);
837	if (err)
838		goto out;
839
840	lbs_queue_event(priv, cause & 0xff);
841out:
842	if (err)
843		netdev_err(priv->dev, "%s: error %d\n", __func__, err);
844}
845
846static void if_spi_host_to_card_worker(struct work_struct *work)
847{
848	int err;
849	struct if_spi_card *card;
850	u16 hiStatus;
851	unsigned long flags;
852	struct if_spi_packet *packet;
853	struct lbs_private *priv;
854
855	card = container_of(work, struct if_spi_card, packet_work);
856	priv = card->priv;
857
858	/*
859	 * Read the host interrupt status register to see what we
860	 * can do.
861	 */
862	err = spu_read_u16(card, IF_SPI_HOST_INT_STATUS_REG,
863				&hiStatus);
864	if (err) {
865		netdev_err(priv->dev, "I/O error\n");
866		goto err;
867	}
868
869	if (hiStatus & IF_SPI_HIST_CMD_UPLOAD_RDY) {
870		err = if_spi_c2h_cmd(card);
871		if (err)
872			goto err;
873	}
874	if (hiStatus & IF_SPI_HIST_RX_UPLOAD_RDY) {
875		err = if_spi_c2h_data(card);
876		if (err)
877			goto err;
878	}
879
880	/*
881	 * workaround: in PS mode, the card does not set the Command
882	 * Download Ready bit, but it sets TX Download Ready.
883	 */
884	if (hiStatus & IF_SPI_HIST_CMD_DOWNLOAD_RDY ||
885	   (card->priv->psstate != PS_STATE_FULL_POWER &&
886	    (hiStatus & IF_SPI_HIST_TX_DOWNLOAD_RDY))) {
887		/*
888		 * This means two things. First of all,
889		 * if there was a previous command sent, the card has
890		 * successfully received it.
891		 * Secondly, it is now ready to download another
892		 * command.
893		 */
894		lbs_host_to_card_done(card->priv);
895
896		/* Do we have any command packets from the host to send? */
897		packet = NULL;
898		spin_lock_irqsave(&card->buffer_lock, flags);
899		if (!list_empty(&card->cmd_packet_list)) {
900			packet = (struct if_spi_packet *)(card->
901					cmd_packet_list.next);
902			list_del(&packet->list);
903		}
904		spin_unlock_irqrestore(&card->buffer_lock, flags);
905
906		if (packet)
907			if_spi_h2c(card, packet, MVMS_CMD);
908	}
909	if (hiStatus & IF_SPI_HIST_TX_DOWNLOAD_RDY) {
910		/* Do we have any data packets from the host to send? */
911		packet = NULL;
912		spin_lock_irqsave(&card->buffer_lock, flags);
913		if (!list_empty(&card->data_packet_list)) {
914			packet = (struct if_spi_packet *)(card->
915					data_packet_list.next);
916			list_del(&packet->list);
917		}
918		spin_unlock_irqrestore(&card->buffer_lock, flags);
919
920		if (packet)
921			if_spi_h2c(card, packet, MVMS_DAT);
922	}
923	if (hiStatus & IF_SPI_HIST_CARD_EVENT)
924		if_spi_e2h(card);
925
926err:
927	if (err)
928		netdev_err(priv->dev, "%s: got error %d\n", __func__, err);
929}
930
931/*
932 * Host to Card
933 *
934 * Called from Libertas to transfer some data to the WLAN device
935 * We can't sleep here.
936 */
937static int if_spi_host_to_card(struct lbs_private *priv,
938				u8 type, u8 *buf, u16 nb)
939{
940	int err = 0;
941	unsigned long flags;
942	struct if_spi_card *card = priv->card;
943	struct if_spi_packet *packet;
944	u16 blen;
945
946	if (nb == 0) {
947		netdev_err(priv->dev, "%s: invalid size requested: %d\n",
948			   __func__, nb);
949		err = -EINVAL;
950		goto out;
951	}
952	blen = ALIGN(nb, 4);
953	packet = kzalloc(sizeof(struct if_spi_packet) + blen, GFP_ATOMIC);
954	if (!packet) {
955		err = -ENOMEM;
956		goto out;
957	}
958	packet->blen = blen;
959	memcpy(packet->buffer, buf, nb);
960	memset(packet->buffer + nb, 0, blen - nb);
961
962	switch (type) {
963	case MVMS_CMD:
964		priv->dnld_sent = DNLD_CMD_SENT;
965		spin_lock_irqsave(&card->buffer_lock, flags);
966		list_add_tail(&packet->list, &card->cmd_packet_list);
967		spin_unlock_irqrestore(&card->buffer_lock, flags);
968		break;
969	case MVMS_DAT:
970		priv->dnld_sent = DNLD_DATA_SENT;
971		spin_lock_irqsave(&card->buffer_lock, flags);
972		list_add_tail(&packet->list, &card->data_packet_list);
973		spin_unlock_irqrestore(&card->buffer_lock, flags);
974		break;
975	default:
976		kfree(packet);
977		netdev_err(priv->dev, "can't transfer buffer of type %d\n",
978			   type);
979		err = -EINVAL;
980		break;
981	}
982
983	/* Queue spi xfer work */
984	queue_work(card->workqueue, &card->packet_work);
985out:
986	return err;
987}
988
989/*
990 * Host Interrupts
991 *
992 * Service incoming interrupts from the WLAN device. We can't sleep here, so
993 * don't try to talk on the SPI bus, just queue the SPI xfer work.
994 */
995static irqreturn_t if_spi_host_interrupt(int irq, void *dev_id)
996{
997	struct if_spi_card *card = dev_id;
998
999	queue_work(card->workqueue, &card->packet_work);
1000
1001	return IRQ_HANDLED;
1002}
1003
1004/*
1005 * SPI callbacks
1006 */
1007
1008static int if_spi_init_card(struct if_spi_card *card)
1009{
1010	struct lbs_private *priv = card->priv;
1011	int err, i;
1012	u32 scratch;
1013	const struct firmware *helper = NULL;
1014	const struct firmware *mainfw = NULL;
1015
1016	err = spu_init(card, card->pdata->use_dummy_writes);
1017	if (err)
1018		goto out;
1019	err = spu_get_chip_revision(card, &card->card_id, &card->card_rev);
1020	if (err)
1021		goto out;
1022
1023	err = spu_read_u32(card, IF_SPI_SCRATCH_4_REG, &scratch);
1024	if (err)
1025		goto out;
1026	if (scratch == SUCCESSFUL_FW_DOWNLOAD_MAGIC)
1027		lbs_deb_spi("Firmware is already loaded for "
1028			    "Marvell WLAN 802.11 adapter\n");
1029	else {
1030		/* Check if we support this card */
1031		for (i = 0; i < ARRAY_SIZE(fw_table); i++) {
1032			if (card->card_id == fw_table[i].model)
1033				break;
1034		}
1035		if (i == ARRAY_SIZE(fw_table)) {
1036			netdev_err(priv->dev, "Unsupported chip_id: 0x%02x\n",
1037				   card->card_id);
1038			err = -ENODEV;
1039			goto out;
1040		}
1041
1042		err = lbs_get_firmware(&card->spi->dev, card->card_id,
1043					&fw_table[0], &helper, &mainfw);
1044		if (err) {
1045			netdev_err(priv->dev, "failed to find firmware (%d)\n",
1046				   err);
1047			goto out;
1048		}
1049
1050		lbs_deb_spi("Initializing FW for Marvell WLAN 802.11 adapter "
1051				"(chip_id = 0x%04x, chip_rev = 0x%02x) "
1052				"attached to SPI bus_num %d, chip_select %d. "
1053				"spi->max_speed_hz=%d\n",
1054				card->card_id, card->card_rev,
1055				card->spi->controller->bus_num,
1056				spi_get_chipselect(card->spi, 0),
1057				card->spi->max_speed_hz);
1058		err = if_spi_prog_helper_firmware(card, helper);
1059		if (err)
1060			goto out;
1061		err = if_spi_prog_main_firmware(card, mainfw);
1062		if (err)
1063			goto out;
1064		lbs_deb_spi("loaded FW for Marvell WLAN 802.11 adapter\n");
1065	}
1066
1067	err = spu_set_interrupt_mode(card, 0, 1);
1068	if (err)
1069		goto out;
1070
1071out:
1072	return err;
1073}
1074
1075static void if_spi_resume_worker(struct work_struct *work)
1076{
1077	struct if_spi_card *card;
1078
1079	card = container_of(work, struct if_spi_card, resume_work);
1080
1081	if (card->suspended) {
1082		if (card->pdata->setup)
1083			card->pdata->setup(card->spi);
1084
1085		/* Init card ... */
1086		if_spi_init_card(card);
1087
1088		enable_irq(card->spi->irq);
1089
1090		/* And resume it ... */
1091		lbs_resume(card->priv);
1092
1093		card->suspended = 0;
1094	}
1095}
1096
1097static int if_spi_probe(struct spi_device *spi)
1098{
1099	struct if_spi_card *card;
1100	struct lbs_private *priv = NULL;
1101	struct libertas_spi_platform_data *pdata = dev_get_platdata(&spi->dev);
1102	int err = 0;
1103
1104	if (!pdata) {
1105		err = -EINVAL;
1106		goto out;
1107	}
1108
1109	if (pdata->setup) {
1110		err = pdata->setup(spi);
1111		if (err)
1112			goto out;
1113	}
1114
1115	/* Allocate card structure to represent this specific device */
1116	card = kzalloc(sizeof(struct if_spi_card), GFP_KERNEL);
1117	if (!card) {
1118		err = -ENOMEM;
1119		goto teardown;
1120	}
1121	spi_set_drvdata(spi, card);
1122	card->pdata = pdata;
1123	card->spi = spi;
1124	card->prev_xfer_time = jiffies;
1125
1126	INIT_LIST_HEAD(&card->cmd_packet_list);
1127	INIT_LIST_HEAD(&card->data_packet_list);
1128	spin_lock_init(&card->buffer_lock);
1129
1130	/* Initialize the SPI Interface Unit */
1131
1132	/* Firmware load */
1133	err = if_spi_init_card(card);
1134	if (err)
1135		goto free_card;
1136
1137	/*
1138	 * Register our card with libertas.
1139	 * This will call alloc_etherdev.
1140	 */
1141	priv = lbs_add_card(card, &spi->dev);
1142	if (IS_ERR(priv)) {
1143		err = PTR_ERR(priv);
1144		goto free_card;
1145	}
1146	card->priv = priv;
1147	priv->setup_fw_on_resume = 1;
1148	priv->card = card;
1149	priv->hw_host_to_card = if_spi_host_to_card;
1150	priv->enter_deep_sleep = NULL;
1151	priv->exit_deep_sleep = NULL;
1152	priv->reset_deep_sleep_wakeup = NULL;
1153	priv->fw_ready = 1;
1154
1155	/* Initialize interrupt handling stuff. */
1156	card->workqueue = alloc_workqueue("libertas_spi", WQ_MEM_RECLAIM, 0);
1157	if (!card->workqueue) {
1158		err = -ENOMEM;
1159		goto remove_card;
1160	}
1161	INIT_WORK(&card->packet_work, if_spi_host_to_card_worker);
1162	INIT_WORK(&card->resume_work, if_spi_resume_worker);
1163
1164	err = request_irq(spi->irq, if_spi_host_interrupt,
1165			IRQF_TRIGGER_FALLING, "libertas_spi", card);
1166	if (err) {
1167		pr_err("can't get host irq line-- request_irq failed\n");
1168		goto terminate_workqueue;
1169	}
1170
1171	/*
1172	 * Start the card.
1173	 * This will call register_netdev, and we'll start
1174	 * getting interrupts...
1175	 */
1176	err = lbs_start_card(priv);
1177	if (err)
1178		goto release_irq;
1179
1180	lbs_deb_spi("Finished initializing WLAN module.\n");
1181
1182	/* successful exit */
1183	goto out;
1184
1185release_irq:
1186	free_irq(spi->irq, card);
1187terminate_workqueue:
1188	destroy_workqueue(card->workqueue);
1189remove_card:
1190	lbs_remove_card(priv); /* will call free_netdev */
1191free_card:
1192	free_if_spi_card(card);
1193teardown:
1194	if (pdata->teardown)
1195		pdata->teardown(spi);
1196out:
1197	return err;
1198}
1199
1200static void libertas_spi_remove(struct spi_device *spi)
1201{
1202	struct if_spi_card *card = spi_get_drvdata(spi);
1203	struct lbs_private *priv = card->priv;
1204
1205	lbs_deb_spi("libertas_spi_remove\n");
1206
1207	cancel_work_sync(&card->resume_work);
1208
1209	lbs_stop_card(priv);
1210	lbs_remove_card(priv); /* will call free_netdev */
1211
1212	free_irq(spi->irq, card);
1213	destroy_workqueue(card->workqueue);
1214	if (card->pdata->teardown)
1215		card->pdata->teardown(spi);
1216	free_if_spi_card(card);
1217}
1218
1219static int if_spi_suspend(struct device *dev)
1220{
1221	struct spi_device *spi = to_spi_device(dev);
1222	struct if_spi_card *card = spi_get_drvdata(spi);
1223
1224	if (!card->suspended) {
1225		lbs_suspend(card->priv);
1226		flush_workqueue(card->workqueue);
1227		disable_irq(spi->irq);
1228
1229		if (card->pdata->teardown)
1230			card->pdata->teardown(spi);
1231		card->suspended = 1;
1232	}
1233
1234	return 0;
1235}
1236
1237static int if_spi_resume(struct device *dev)
1238{
1239	struct spi_device *spi = to_spi_device(dev);
1240	struct if_spi_card *card = spi_get_drvdata(spi);
1241
1242	/* Schedule delayed work */
1243	schedule_work(&card->resume_work);
1244
1245	return 0;
1246}
1247
1248static const struct dev_pm_ops if_spi_pm_ops = {
1249	.suspend	= if_spi_suspend,
1250	.resume		= if_spi_resume,
1251};
1252
1253static struct spi_driver libertas_spi_driver = {
1254	.probe	= if_spi_probe,
1255	.remove = libertas_spi_remove,
1256	.driver = {
1257		.name	= "libertas_spi",
1258		.pm	= &if_spi_pm_ops,
1259	},
1260};
1261
1262/*
1263 * Module functions
1264 */
1265
1266static int __init if_spi_init_module(void)
1267{
1268	int ret = 0;
1269
1270	printk(KERN_INFO "libertas_spi: Libertas SPI driver\n");
1271	ret = spi_register_driver(&libertas_spi_driver);
1272
1273	return ret;
1274}
1275
1276static void __exit if_spi_exit_module(void)
1277{
1278	spi_unregister_driver(&libertas_spi_driver);
1279}
1280
1281module_init(if_spi_init_module);
1282module_exit(if_spi_exit_module);
1283
1284MODULE_DESCRIPTION("Libertas SPI WLAN Driver");
1285MODULE_AUTHOR("Andrey Yurovsky <andrey@cozybit.com>, "
1286	      "Colin McCabe <colin@cozybit.com>");
1287MODULE_LICENSE("GPL");
1288MODULE_ALIAS("spi:libertas_spi");
1289