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 
35 struct if_spi_packet {
36 	struct list_head		list;
37 	u16				blen;
38 	u8				buffer[] __aligned(4);
39 };
40 
41 struct 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 
77 static 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 
96 static 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 };
104 MODULE_FIRMWARE("libertas/gspi8385_helper.bin");
105 MODULE_FIRMWARE("libertas/gspi8385_hlp.bin");
106 MODULE_FIRMWARE("libertas/gspi8385.bin");
107 MODULE_FIRMWARE("libertas/gspi8686_v9_helper.bin");
108 MODULE_FIRMWARE("libertas/gspi8686_v9.bin");
109 MODULE_FIRMWARE("libertas/gspi8686_hlp.bin");
110 MODULE_FIRMWARE("libertas/gspi8686.bin");
111 MODULE_FIRMWARE("libertas/gspi8688_helper.bin");
112 MODULE_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 
126 static 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 
137 static 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  */
146 static 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 
179 static 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 
187 static 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 
199 static 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 */
251 static 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  */
266 static 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  */
286 static 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  */
316 static 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 
331 static 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 
378 static 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 
391 static 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 
410 static 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 
455 static 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);
525 out:
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  */
536 static 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 
574 static 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 
656 out:
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 */
670 static 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 
723 out:
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 */
731 static 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 
776 out:
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. */
784 static 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 
810 out:
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 */
818 static 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);
841 out:
842 	if (err)
843 		netdev_err(priv->dev, "%s: error %d\n", __func__, err);
844 }
845 
846 static 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 
926 err:
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  */
937 static 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);
985 out:
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  */
995 static 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 
1008 static 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->master->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 
1071 out:
1072 	return err;
1073 }
1074 
1075 static 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 
1097 static 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 
1185 release_irq:
1186 	free_irq(spi->irq, card);
1187 terminate_workqueue:
1188 	destroy_workqueue(card->workqueue);
1189 remove_card:
1190 	lbs_remove_card(priv); /* will call free_netdev */
1191 free_card:
1192 	free_if_spi_card(card);
1193 teardown:
1194 	if (pdata->teardown)
1195 		pdata->teardown(spi);
1196 out:
1197 	return err;
1198 }
1199 
1200 static 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 
1219 static 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 
1237 static 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 
1248 static const struct dev_pm_ops if_spi_pm_ops = {
1249 	.suspend	= if_spi_suspend,
1250 	.resume		= if_spi_resume,
1251 };
1252 
1253 static 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 
1266 static 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 
1276 static void __exit if_spi_exit_module(void)
1277 {
1278 	spi_unregister_driver(&libertas_spi_driver);
1279 }
1280 
1281 module_init(if_spi_init_module);
1282 module_exit(if_spi_exit_module);
1283 
1284 MODULE_DESCRIPTION("Libertas SPI WLAN Driver");
1285 MODULE_AUTHOR("Andrey Yurovsky <andrey@cozybit.com>, "
1286 	      "Colin McCabe <colin@cozybit.com>");
1287 MODULE_LICENSE("GPL");
1288 MODULE_ALIAS("spi:libertas_spi");
1289