1 /*
2 * Copyright (C) ST-Ericsson AB 2010
3 * Author: Daniel Martensson
4 * License terms: GNU General Public License (GPL) version 2.
5 */
6
7 #include <linux/init.h>
8 #include <linux/module.h>
9 #include <linux/device.h>
10 #include <linux/platform_device.h>
11 #include <linux/string.h>
12 #include <linux/workqueue.h>
13 #include <linux/completion.h>
14 #include <linux/list.h>
15 #include <linux/interrupt.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/delay.h>
18 #include <linux/sched.h>
19 #include <linux/debugfs.h>
20 #include <linux/if_arp.h>
21 #include <net/caif/caif_layer.h>
22 #include <net/caif/caif_spi.h>
23
24 #ifndef CONFIG_CAIF_SPI_SYNC
25 #define FLAVOR "Flavour: Vanilla.\n"
26 #else
27 #define FLAVOR "Flavour: Master CMD&LEN at start.\n"
28 #endif /* CONFIG_CAIF_SPI_SYNC */
29
30 MODULE_LICENSE("GPL");
31 MODULE_AUTHOR("Daniel Martensson");
32 MODULE_DESCRIPTION("CAIF SPI driver");
33
34 /* Returns the number of padding bytes for alignment. */
35 #define PAD_POW2(x, pow) ((((x)&((pow)-1))==0) ? 0 : (((pow)-((x)&((pow)-1)))))
36
37 static bool spi_loop;
38 module_param(spi_loop, bool, S_IRUGO);
39 MODULE_PARM_DESC(spi_loop, "SPI running in loopback mode.");
40
41 /* SPI frame alignment. */
42 module_param(spi_frm_align, int, S_IRUGO);
43 MODULE_PARM_DESC(spi_frm_align, "SPI frame alignment.");
44
45 /*
46 * SPI padding options.
47 * Warning: must be a base of 2 (& operation used) and can not be zero !
48 */
49 module_param(spi_up_head_align, int, S_IRUGO);
50 MODULE_PARM_DESC(spi_up_head_align, "SPI uplink head alignment.");
51
52 module_param(spi_up_tail_align, int, S_IRUGO);
53 MODULE_PARM_DESC(spi_up_tail_align, "SPI uplink tail alignment.");
54
55 module_param(spi_down_head_align, int, S_IRUGO);
56 MODULE_PARM_DESC(spi_down_head_align, "SPI downlink head alignment.");
57
58 module_param(spi_down_tail_align, int, S_IRUGO);
59 MODULE_PARM_DESC(spi_down_tail_align, "SPI downlink tail alignment.");
60
61 #ifdef CONFIG_ARM
62 #define BYTE_HEX_FMT "%02X"
63 #else
64 #define BYTE_HEX_FMT "%02hhX"
65 #endif
66
67 #define SPI_MAX_PAYLOAD_SIZE 4096
68 /*
69 * Threshold values for the SPI packet queue. Flowcontrol will be asserted
70 * when the number of packets exceeds HIGH_WATER_MARK. It will not be
71 * deasserted before the number of packets drops below LOW_WATER_MARK.
72 */
73 #define LOW_WATER_MARK 100
74 #define HIGH_WATER_MARK (LOW_WATER_MARK*5)
75
76 #ifdef CONFIG_UML
77
78 /*
79 * We sometimes use UML for debugging, but it cannot handle
80 * dma_alloc_coherent so we have to wrap it.
81 */
dma_alloc(dma_addr_t * daddr)82 static inline void *dma_alloc(dma_addr_t *daddr)
83 {
84 return kmalloc(SPI_DMA_BUF_LEN, GFP_KERNEL);
85 }
86
dma_free(void * cpu_addr,dma_addr_t handle)87 static inline void dma_free(void *cpu_addr, dma_addr_t handle)
88 {
89 kfree(cpu_addr);
90 }
91
92 #else
93
dma_alloc(dma_addr_t * daddr)94 static inline void *dma_alloc(dma_addr_t *daddr)
95 {
96 return dma_alloc_coherent(NULL, SPI_DMA_BUF_LEN, daddr,
97 GFP_KERNEL);
98 }
99
dma_free(void * cpu_addr,dma_addr_t handle)100 static inline void dma_free(void *cpu_addr, dma_addr_t handle)
101 {
102 dma_free_coherent(NULL, SPI_DMA_BUF_LEN, cpu_addr, handle);
103 }
104 #endif /* CONFIG_UML */
105
106 #ifdef CONFIG_DEBUG_FS
107
108 #define DEBUGFS_BUF_SIZE 4096
109
110 static struct dentry *dbgfs_root;
111
driver_debugfs_create(void)112 static inline void driver_debugfs_create(void)
113 {
114 dbgfs_root = debugfs_create_dir(cfspi_spi_driver.driver.name, NULL);
115 }
116
driver_debugfs_remove(void)117 static inline void driver_debugfs_remove(void)
118 {
119 debugfs_remove(dbgfs_root);
120 }
121
dev_debugfs_rem(struct cfspi * cfspi)122 static inline void dev_debugfs_rem(struct cfspi *cfspi)
123 {
124 debugfs_remove(cfspi->dbgfs_frame);
125 debugfs_remove(cfspi->dbgfs_state);
126 debugfs_remove(cfspi->dbgfs_dir);
127 }
128
dbgfs_state(struct file * file,char __user * user_buf,size_t count,loff_t * ppos)129 static ssize_t dbgfs_state(struct file *file, char __user *user_buf,
130 size_t count, loff_t *ppos)
131 {
132 char *buf;
133 int len = 0;
134 ssize_t size;
135 struct cfspi *cfspi = file->private_data;
136
137 buf = kzalloc(DEBUGFS_BUF_SIZE, GFP_KERNEL);
138 if (!buf)
139 return 0;
140
141 /* Print out debug information. */
142 len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
143 "CAIF SPI debug information:\n");
144
145 len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), FLAVOR);
146
147 len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
148 "STATE: %d\n", cfspi->dbg_state);
149 len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
150 "Previous CMD: 0x%x\n", cfspi->pcmd);
151 len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
152 "Current CMD: 0x%x\n", cfspi->cmd);
153 len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
154 "Previous TX len: %d\n", cfspi->tx_ppck_len);
155 len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
156 "Previous RX len: %d\n", cfspi->rx_ppck_len);
157 len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
158 "Current TX len: %d\n", cfspi->tx_cpck_len);
159 len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
160 "Current RX len: %d\n", cfspi->rx_cpck_len);
161 len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
162 "Next TX len: %d\n", cfspi->tx_npck_len);
163 len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
164 "Next RX len: %d\n", cfspi->rx_npck_len);
165
166 if (len > DEBUGFS_BUF_SIZE)
167 len = DEBUGFS_BUF_SIZE;
168
169 size = simple_read_from_buffer(user_buf, count, ppos, buf, len);
170 kfree(buf);
171
172 return size;
173 }
174
print_frame(char * buf,size_t size,char * frm,size_t count,size_t cut)175 static ssize_t print_frame(char *buf, size_t size, char *frm,
176 size_t count, size_t cut)
177 {
178 int len = 0;
179 int i;
180 for (i = 0; i < count; i++) {
181 len += snprintf((buf + len), (size - len),
182 "[0x" BYTE_HEX_FMT "]",
183 frm[i]);
184 if ((i == cut) && (count > (cut * 2))) {
185 /* Fast forward. */
186 i = count - cut;
187 len += snprintf((buf + len), (size - len),
188 "--- %u bytes skipped ---\n",
189 (int)(count - (cut * 2)));
190 }
191
192 if ((!(i % 10)) && i) {
193 len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
194 "\n");
195 }
196 }
197 len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len), "\n");
198 return len;
199 }
200
dbgfs_frame(struct file * file,char __user * user_buf,size_t count,loff_t * ppos)201 static ssize_t dbgfs_frame(struct file *file, char __user *user_buf,
202 size_t count, loff_t *ppos)
203 {
204 char *buf;
205 int len = 0;
206 ssize_t size;
207 struct cfspi *cfspi;
208
209 cfspi = file->private_data;
210 buf = kzalloc(DEBUGFS_BUF_SIZE, GFP_KERNEL);
211 if (!buf)
212 return 0;
213
214 /* Print out debug information. */
215 len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
216 "Current frame:\n");
217
218 len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
219 "Tx data (Len: %d):\n", cfspi->tx_cpck_len);
220
221 len += print_frame((buf + len), (DEBUGFS_BUF_SIZE - len),
222 cfspi->xfer.va_tx[0],
223 (cfspi->tx_cpck_len + SPI_CMD_SZ), 100);
224
225 len += snprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
226 "Rx data (Len: %d):\n", cfspi->rx_cpck_len);
227
228 len += print_frame((buf + len), (DEBUGFS_BUF_SIZE - len),
229 cfspi->xfer.va_rx,
230 (cfspi->rx_cpck_len + SPI_CMD_SZ), 100);
231
232 size = simple_read_from_buffer(user_buf, count, ppos, buf, len);
233 kfree(buf);
234
235 return size;
236 }
237
238 static const struct file_operations dbgfs_state_fops = {
239 .open = simple_open,
240 .read = dbgfs_state,
241 .owner = THIS_MODULE
242 };
243
244 static const struct file_operations dbgfs_frame_fops = {
245 .open = simple_open,
246 .read = dbgfs_frame,
247 .owner = THIS_MODULE
248 };
249
dev_debugfs_add(struct cfspi * cfspi)250 static inline void dev_debugfs_add(struct cfspi *cfspi)
251 {
252 cfspi->dbgfs_dir = debugfs_create_dir(cfspi->pdev->name, dbgfs_root);
253 cfspi->dbgfs_state = debugfs_create_file("state", S_IRUGO,
254 cfspi->dbgfs_dir, cfspi,
255 &dbgfs_state_fops);
256 cfspi->dbgfs_frame = debugfs_create_file("frame", S_IRUGO,
257 cfspi->dbgfs_dir, cfspi,
258 &dbgfs_frame_fops);
259 }
260
cfspi_dbg_state(struct cfspi * cfspi,int state)261 inline void cfspi_dbg_state(struct cfspi *cfspi, int state)
262 {
263 cfspi->dbg_state = state;
264 };
265 #else
266
driver_debugfs_create(void)267 static inline void driver_debugfs_create(void)
268 {
269 }
270
driver_debugfs_remove(void)271 static inline void driver_debugfs_remove(void)
272 {
273 }
274
dev_debugfs_add(struct cfspi * cfspi)275 static inline void dev_debugfs_add(struct cfspi *cfspi)
276 {
277 }
278
dev_debugfs_rem(struct cfspi * cfspi)279 static inline void dev_debugfs_rem(struct cfspi *cfspi)
280 {
281 }
282
cfspi_dbg_state(struct cfspi * cfspi,int state)283 inline void cfspi_dbg_state(struct cfspi *cfspi, int state)
284 {
285 }
286 #endif /* CONFIG_DEBUG_FS */
287
288 static LIST_HEAD(cfspi_list);
289 static spinlock_t cfspi_list_lock;
290
291 /* SPI uplink head alignment. */
show_up_head_align(struct device_driver * driver,char * buf)292 static ssize_t show_up_head_align(struct device_driver *driver, char *buf)
293 {
294 return sprintf(buf, "%d\n", spi_up_head_align);
295 }
296
297 static DRIVER_ATTR(up_head_align, S_IRUSR, show_up_head_align, NULL);
298
299 /* SPI uplink tail alignment. */
show_up_tail_align(struct device_driver * driver,char * buf)300 static ssize_t show_up_tail_align(struct device_driver *driver, char *buf)
301 {
302 return sprintf(buf, "%d\n", spi_up_tail_align);
303 }
304
305 static DRIVER_ATTR(up_tail_align, S_IRUSR, show_up_tail_align, NULL);
306
307 /* SPI downlink head alignment. */
show_down_head_align(struct device_driver * driver,char * buf)308 static ssize_t show_down_head_align(struct device_driver *driver, char *buf)
309 {
310 return sprintf(buf, "%d\n", spi_down_head_align);
311 }
312
313 static DRIVER_ATTR(down_head_align, S_IRUSR, show_down_head_align, NULL);
314
315 /* SPI downlink tail alignment. */
show_down_tail_align(struct device_driver * driver,char * buf)316 static ssize_t show_down_tail_align(struct device_driver *driver, char *buf)
317 {
318 return sprintf(buf, "%d\n", spi_down_tail_align);
319 }
320
321 static DRIVER_ATTR(down_tail_align, S_IRUSR, show_down_tail_align, NULL);
322
323 /* SPI frame alignment. */
show_frame_align(struct device_driver * driver,char * buf)324 static ssize_t show_frame_align(struct device_driver *driver, char *buf)
325 {
326 return sprintf(buf, "%d\n", spi_frm_align);
327 }
328
329 static DRIVER_ATTR(frame_align, S_IRUSR, show_frame_align, NULL);
330
cfspi_xmitfrm(struct cfspi * cfspi,u8 * buf,size_t len)331 int cfspi_xmitfrm(struct cfspi *cfspi, u8 *buf, size_t len)
332 {
333 u8 *dst = buf;
334 caif_assert(buf);
335
336 if (cfspi->slave && !cfspi->slave_talked)
337 cfspi->slave_talked = true;
338
339 do {
340 struct sk_buff *skb;
341 struct caif_payload_info *info;
342 int spad = 0;
343 int epad;
344
345 skb = skb_dequeue(&cfspi->chead);
346 if (!skb)
347 break;
348
349 /*
350 * Calculate length of frame including SPI padding.
351 * The payload position is found in the control buffer.
352 */
353 info = (struct caif_payload_info *)&skb->cb;
354
355 /*
356 * Compute head offset i.e. number of bytes to add to
357 * get the start of the payload aligned.
358 */
359 if (spi_up_head_align > 1) {
360 spad = 1 + PAD_POW2((info->hdr_len + 1), spi_up_head_align);
361 *dst = (u8)(spad - 1);
362 dst += spad;
363 }
364
365 /* Copy in CAIF frame. */
366 skb_copy_bits(skb, 0, dst, skb->len);
367 dst += skb->len;
368 cfspi->ndev->stats.tx_packets++;
369 cfspi->ndev->stats.tx_bytes += skb->len;
370
371 /*
372 * Compute tail offset i.e. number of bytes to add to
373 * get the complete CAIF frame aligned.
374 */
375 epad = PAD_POW2((skb->len + spad), spi_up_tail_align);
376 dst += epad;
377
378 dev_kfree_skb(skb);
379
380 } while ((dst - buf) < len);
381
382 return dst - buf;
383 }
384
cfspi_xmitlen(struct cfspi * cfspi)385 int cfspi_xmitlen(struct cfspi *cfspi)
386 {
387 struct sk_buff *skb = NULL;
388 int frm_len = 0;
389 int pkts = 0;
390
391 /*
392 * Decommit previously committed frames.
393 * skb_queue_splice_tail(&cfspi->chead,&cfspi->qhead)
394 */
395 while (skb_peek(&cfspi->chead)) {
396 skb = skb_dequeue_tail(&cfspi->chead);
397 skb_queue_head(&cfspi->qhead, skb);
398 }
399
400 do {
401 struct caif_payload_info *info = NULL;
402 int spad = 0;
403 int epad = 0;
404
405 skb = skb_dequeue(&cfspi->qhead);
406 if (!skb)
407 break;
408
409 /*
410 * Calculate length of frame including SPI padding.
411 * The payload position is found in the control buffer.
412 */
413 info = (struct caif_payload_info *)&skb->cb;
414
415 /*
416 * Compute head offset i.e. number of bytes to add to
417 * get the start of the payload aligned.
418 */
419 if (spi_up_head_align > 1)
420 spad = 1 + PAD_POW2((info->hdr_len + 1), spi_up_head_align);
421
422 /*
423 * Compute tail offset i.e. number of bytes to add to
424 * get the complete CAIF frame aligned.
425 */
426 epad = PAD_POW2((skb->len + spad), spi_up_tail_align);
427
428 if ((skb->len + spad + epad + frm_len) <= CAIF_MAX_SPI_FRAME) {
429 skb_queue_tail(&cfspi->chead, skb);
430 pkts++;
431 frm_len += skb->len + spad + epad;
432 } else {
433 /* Put back packet. */
434 skb_queue_head(&cfspi->qhead, skb);
435 break;
436 }
437 } while (pkts <= CAIF_MAX_SPI_PKTS);
438
439 /*
440 * Send flow on if previously sent flow off
441 * and now go below the low water mark
442 */
443 if (cfspi->flow_off_sent && cfspi->qhead.qlen < cfspi->qd_low_mark &&
444 cfspi->cfdev.flowctrl) {
445 cfspi->flow_off_sent = 0;
446 cfspi->cfdev.flowctrl(cfspi->ndev, 1);
447 }
448
449 return frm_len;
450 }
451
cfspi_ss_cb(bool assert,struct cfspi_ifc * ifc)452 static void cfspi_ss_cb(bool assert, struct cfspi_ifc *ifc)
453 {
454 struct cfspi *cfspi = (struct cfspi *)ifc->priv;
455
456 /*
457 * The slave device is the master on the link. Interrupts before the
458 * slave has transmitted are considered spurious.
459 */
460 if (cfspi->slave && !cfspi->slave_talked) {
461 printk(KERN_WARNING "CFSPI: Spurious SS interrupt.\n");
462 return;
463 }
464
465 if (!in_interrupt())
466 spin_lock(&cfspi->lock);
467 if (assert) {
468 set_bit(SPI_SS_ON, &cfspi->state);
469 set_bit(SPI_XFER, &cfspi->state);
470 } else {
471 set_bit(SPI_SS_OFF, &cfspi->state);
472 }
473 if (!in_interrupt())
474 spin_unlock(&cfspi->lock);
475
476 /* Wake up the xfer thread. */
477 if (assert)
478 wake_up_interruptible(&cfspi->wait);
479 }
480
cfspi_xfer_done_cb(struct cfspi_ifc * ifc)481 static void cfspi_xfer_done_cb(struct cfspi_ifc *ifc)
482 {
483 struct cfspi *cfspi = (struct cfspi *)ifc->priv;
484
485 /* Transfer done, complete work queue */
486 complete(&cfspi->comp);
487 }
488
cfspi_xmit(struct sk_buff * skb,struct net_device * dev)489 static int cfspi_xmit(struct sk_buff *skb, struct net_device *dev)
490 {
491 struct cfspi *cfspi = NULL;
492 unsigned long flags;
493 if (!dev)
494 return -EINVAL;
495
496 cfspi = netdev_priv(dev);
497
498 skb_queue_tail(&cfspi->qhead, skb);
499
500 spin_lock_irqsave(&cfspi->lock, flags);
501 if (!test_and_set_bit(SPI_XFER, &cfspi->state)) {
502 /* Wake up xfer thread. */
503 wake_up_interruptible(&cfspi->wait);
504 }
505 spin_unlock_irqrestore(&cfspi->lock, flags);
506
507 /* Send flow off if number of bytes is above high water mark */
508 if (!cfspi->flow_off_sent &&
509 cfspi->qhead.qlen > cfspi->qd_high_mark &&
510 cfspi->cfdev.flowctrl) {
511 cfspi->flow_off_sent = 1;
512 cfspi->cfdev.flowctrl(cfspi->ndev, 0);
513 }
514
515 return 0;
516 }
517
cfspi_rxfrm(struct cfspi * cfspi,u8 * buf,size_t len)518 int cfspi_rxfrm(struct cfspi *cfspi, u8 *buf, size_t len)
519 {
520 u8 *src = buf;
521
522 caif_assert(buf != NULL);
523
524 do {
525 int res;
526 struct sk_buff *skb = NULL;
527 int spad = 0;
528 int epad = 0;
529 u8 *dst = NULL;
530 int pkt_len = 0;
531
532 /*
533 * Compute head offset i.e. number of bytes added to
534 * get the start of the payload aligned.
535 */
536 if (spi_down_head_align > 1) {
537 spad = 1 + *src;
538 src += spad;
539 }
540
541 /* Read length of CAIF frame (little endian). */
542 pkt_len = *src;
543 pkt_len |= ((*(src+1)) << 8) & 0xFF00;
544 pkt_len += 2; /* Add FCS fields. */
545
546 /* Get a suitable caif packet and copy in data. */
547
548 skb = netdev_alloc_skb(cfspi->ndev, pkt_len + 1);
549 caif_assert(skb != NULL);
550
551 dst = skb_put(skb, pkt_len);
552 memcpy(dst, src, pkt_len);
553 src += pkt_len;
554
555 skb->protocol = htons(ETH_P_CAIF);
556 skb_reset_mac_header(skb);
557
558 /*
559 * Push received packet up the stack.
560 */
561 if (!spi_loop)
562 res = netif_rx_ni(skb);
563 else
564 res = cfspi_xmit(skb, cfspi->ndev);
565
566 if (!res) {
567 cfspi->ndev->stats.rx_packets++;
568 cfspi->ndev->stats.rx_bytes += pkt_len;
569 } else
570 cfspi->ndev->stats.rx_dropped++;
571
572 /*
573 * Compute tail offset i.e. number of bytes added to
574 * get the complete CAIF frame aligned.
575 */
576 epad = PAD_POW2((pkt_len + spad), spi_down_tail_align);
577 src += epad;
578 } while ((src - buf) < len);
579
580 return src - buf;
581 }
582
cfspi_open(struct net_device * dev)583 static int cfspi_open(struct net_device *dev)
584 {
585 netif_wake_queue(dev);
586 return 0;
587 }
588
cfspi_close(struct net_device * dev)589 static int cfspi_close(struct net_device *dev)
590 {
591 netif_stop_queue(dev);
592 return 0;
593 }
594
cfspi_init(struct net_device * dev)595 static int cfspi_init(struct net_device *dev)
596 {
597 int res = 0;
598 struct cfspi *cfspi = netdev_priv(dev);
599
600 /* Set flow info. */
601 cfspi->flow_off_sent = 0;
602 cfspi->qd_low_mark = LOW_WATER_MARK;
603 cfspi->qd_high_mark = HIGH_WATER_MARK;
604
605 /* Set slave info. */
606 if (!strncmp(cfspi_spi_driver.driver.name, "cfspi_sspi", 10)) {
607 cfspi->slave = true;
608 cfspi->slave_talked = false;
609 } else {
610 cfspi->slave = false;
611 cfspi->slave_talked = false;
612 }
613
614 /* Allocate DMA buffers. */
615 cfspi->xfer.va_tx[0] = dma_alloc(&cfspi->xfer.pa_tx[0]);
616 if (!cfspi->xfer.va_tx[0]) {
617 res = -ENODEV;
618 goto err_dma_alloc_tx_0;
619 }
620
621 cfspi->xfer.va_rx = dma_alloc(&cfspi->xfer.pa_rx);
622
623 if (!cfspi->xfer.va_rx) {
624 res = -ENODEV;
625 goto err_dma_alloc_rx;
626 }
627
628 /* Initialize the work queue. */
629 INIT_WORK(&cfspi->work, cfspi_xfer);
630
631 /* Initialize spin locks. */
632 spin_lock_init(&cfspi->lock);
633
634 /* Initialize flow control state. */
635 cfspi->flow_stop = false;
636
637 /* Initialize wait queue. */
638 init_waitqueue_head(&cfspi->wait);
639
640 /* Create work thread. */
641 cfspi->wq = create_singlethread_workqueue(dev->name);
642 if (!cfspi->wq) {
643 printk(KERN_WARNING "CFSPI: failed to create work queue.\n");
644 res = -ENODEV;
645 goto err_create_wq;
646 }
647
648 /* Initialize work queue. */
649 init_completion(&cfspi->comp);
650
651 /* Create debugfs entries. */
652 dev_debugfs_add(cfspi);
653
654 /* Set up the ifc. */
655 cfspi->ifc.ss_cb = cfspi_ss_cb;
656 cfspi->ifc.xfer_done_cb = cfspi_xfer_done_cb;
657 cfspi->ifc.priv = cfspi;
658
659 /* Add CAIF SPI device to list. */
660 spin_lock(&cfspi_list_lock);
661 list_add_tail(&cfspi->list, &cfspi_list);
662 spin_unlock(&cfspi_list_lock);
663
664 /* Schedule the work queue. */
665 queue_work(cfspi->wq, &cfspi->work);
666
667 return 0;
668
669 err_create_wq:
670 dma_free(cfspi->xfer.va_rx, cfspi->xfer.pa_rx);
671 err_dma_alloc_rx:
672 dma_free(cfspi->xfer.va_tx[0], cfspi->xfer.pa_tx[0]);
673 err_dma_alloc_tx_0:
674 return res;
675 }
676
cfspi_uninit(struct net_device * dev)677 static void cfspi_uninit(struct net_device *dev)
678 {
679 struct cfspi *cfspi = netdev_priv(dev);
680
681 /* Remove from list. */
682 spin_lock(&cfspi_list_lock);
683 list_del(&cfspi->list);
684 spin_unlock(&cfspi_list_lock);
685
686 cfspi->ndev = NULL;
687 /* Free DMA buffers. */
688 dma_free(cfspi->xfer.va_rx, cfspi->xfer.pa_rx);
689 dma_free(cfspi->xfer.va_tx[0], cfspi->xfer.pa_tx[0]);
690 set_bit(SPI_TERMINATE, &cfspi->state);
691 wake_up_interruptible(&cfspi->wait);
692 destroy_workqueue(cfspi->wq);
693 /* Destroy debugfs directory and files. */
694 dev_debugfs_rem(cfspi);
695 return;
696 }
697
698 static const struct net_device_ops cfspi_ops = {
699 .ndo_open = cfspi_open,
700 .ndo_stop = cfspi_close,
701 .ndo_init = cfspi_init,
702 .ndo_uninit = cfspi_uninit,
703 .ndo_start_xmit = cfspi_xmit
704 };
705
cfspi_setup(struct net_device * dev)706 static void cfspi_setup(struct net_device *dev)
707 {
708 struct cfspi *cfspi = netdev_priv(dev);
709 dev->features = 0;
710 dev->netdev_ops = &cfspi_ops;
711 dev->type = ARPHRD_CAIF;
712 dev->flags = IFF_NOARP | IFF_POINTOPOINT;
713 dev->tx_queue_len = 0;
714 dev->mtu = SPI_MAX_PAYLOAD_SIZE;
715 dev->destructor = free_netdev;
716 skb_queue_head_init(&cfspi->qhead);
717 skb_queue_head_init(&cfspi->chead);
718 cfspi->cfdev.link_select = CAIF_LINK_HIGH_BANDW;
719 cfspi->cfdev.use_frag = false;
720 cfspi->cfdev.use_stx = false;
721 cfspi->cfdev.use_fcs = false;
722 cfspi->ndev = dev;
723 }
724
cfspi_spi_probe(struct platform_device * pdev)725 int cfspi_spi_probe(struct platform_device *pdev)
726 {
727 struct cfspi *cfspi = NULL;
728 struct net_device *ndev;
729 struct cfspi_dev *dev;
730 int res;
731 dev = (struct cfspi_dev *)pdev->dev.platform_data;
732
733 ndev = alloc_netdev(sizeof(struct cfspi), "cfspi%d",
734 NET_NAME_UNKNOWN, cfspi_setup);
735 if (!dev)
736 return -ENODEV;
737
738 cfspi = netdev_priv(ndev);
739 netif_stop_queue(ndev);
740 cfspi->ndev = ndev;
741 cfspi->pdev = pdev;
742
743 /* Assign the SPI device. */
744 cfspi->dev = dev;
745 /* Assign the device ifc to this SPI interface. */
746 dev->ifc = &cfspi->ifc;
747
748 /* Register network device. */
749 res = register_netdev(ndev);
750 if (res) {
751 printk(KERN_ERR "CFSPI: Reg. error: %d.\n", res);
752 goto err_net_reg;
753 }
754 return res;
755
756 err_net_reg:
757 free_netdev(ndev);
758
759 return res;
760 }
761
cfspi_spi_remove(struct platform_device * pdev)762 int cfspi_spi_remove(struct platform_device *pdev)
763 {
764 /* Everything is done in cfspi_uninit(). */
765 return 0;
766 }
767
cfspi_exit_module(void)768 static void __exit cfspi_exit_module(void)
769 {
770 struct list_head *list_node;
771 struct list_head *n;
772 struct cfspi *cfspi = NULL;
773
774 list_for_each_safe(list_node, n, &cfspi_list) {
775 cfspi = list_entry(list_node, struct cfspi, list);
776 unregister_netdev(cfspi->ndev);
777 }
778
779 /* Destroy sysfs files. */
780 driver_remove_file(&cfspi_spi_driver.driver,
781 &driver_attr_up_head_align);
782 driver_remove_file(&cfspi_spi_driver.driver,
783 &driver_attr_up_tail_align);
784 driver_remove_file(&cfspi_spi_driver.driver,
785 &driver_attr_down_head_align);
786 driver_remove_file(&cfspi_spi_driver.driver,
787 &driver_attr_down_tail_align);
788 driver_remove_file(&cfspi_spi_driver.driver, &driver_attr_frame_align);
789 /* Unregister platform driver. */
790 platform_driver_unregister(&cfspi_spi_driver);
791 /* Destroy debugfs root directory. */
792 driver_debugfs_remove();
793 }
794
cfspi_init_module(void)795 static int __init cfspi_init_module(void)
796 {
797 int result;
798
799 /* Initialize spin lock. */
800 spin_lock_init(&cfspi_list_lock);
801
802 /* Register platform driver. */
803 result = platform_driver_register(&cfspi_spi_driver);
804 if (result) {
805 printk(KERN_ERR "Could not register platform SPI driver.\n");
806 goto err_dev_register;
807 }
808
809 /* Create sysfs files. */
810 result =
811 driver_create_file(&cfspi_spi_driver.driver,
812 &driver_attr_up_head_align);
813 if (result) {
814 printk(KERN_ERR "Sysfs creation failed 1.\n");
815 goto err_create_up_head_align;
816 }
817
818 result =
819 driver_create_file(&cfspi_spi_driver.driver,
820 &driver_attr_up_tail_align);
821 if (result) {
822 printk(KERN_ERR "Sysfs creation failed 2.\n");
823 goto err_create_up_tail_align;
824 }
825
826 result =
827 driver_create_file(&cfspi_spi_driver.driver,
828 &driver_attr_down_head_align);
829 if (result) {
830 printk(KERN_ERR "Sysfs creation failed 3.\n");
831 goto err_create_down_head_align;
832 }
833
834 result =
835 driver_create_file(&cfspi_spi_driver.driver,
836 &driver_attr_down_tail_align);
837 if (result) {
838 printk(KERN_ERR "Sysfs creation failed 4.\n");
839 goto err_create_down_tail_align;
840 }
841
842 result =
843 driver_create_file(&cfspi_spi_driver.driver,
844 &driver_attr_frame_align);
845 if (result) {
846 printk(KERN_ERR "Sysfs creation failed 5.\n");
847 goto err_create_frame_align;
848 }
849 driver_debugfs_create();
850 return result;
851
852 err_create_frame_align:
853 driver_remove_file(&cfspi_spi_driver.driver,
854 &driver_attr_down_tail_align);
855 err_create_down_tail_align:
856 driver_remove_file(&cfspi_spi_driver.driver,
857 &driver_attr_down_head_align);
858 err_create_down_head_align:
859 driver_remove_file(&cfspi_spi_driver.driver,
860 &driver_attr_up_tail_align);
861 err_create_up_tail_align:
862 driver_remove_file(&cfspi_spi_driver.driver,
863 &driver_attr_up_head_align);
864 err_create_up_head_align:
865 platform_driver_unregister(&cfspi_spi_driver);
866 err_dev_register:
867 return result;
868 }
869
870 module_init(cfspi_init_module);
871 module_exit(cfspi_exit_module);
872