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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * FSI core driver
4 *
5 * Copyright (C) IBM Corporation 2016
6 *
7 * TODO:
8 * - Rework topology
9 * - s/chip_id/chip_loc
10 * - s/cfam/chip (cfam_id -> chip_id etc...)
11 */
12
13#include <linux/crc4.h>
14#include <linux/device.h>
15#include <linux/fsi.h>
16#include <linux/idr.h>
17#include <linux/module.h>
18#include <linux/of.h>
19#include <linux/slab.h>
20#include <linux/bitops.h>
21#include <linux/cdev.h>
22#include <linux/fs.h>
23#include <linux/uaccess.h>
24
25#include "fsi-master.h"
26
27#define CREATE_TRACE_POINTS
28#include <trace/events/fsi.h>
29
30#define FSI_SLAVE_CONF_NEXT_MASK GENMASK(31, 31)
31#define FSI_SLAVE_CONF_SLOTS_MASK GENMASK(23, 16)
32#define FSI_SLAVE_CONF_SLOTS_SHIFT 16
33#define FSI_SLAVE_CONF_VERSION_MASK GENMASK(15, 12)
34#define FSI_SLAVE_CONF_VERSION_SHIFT 12
35#define FSI_SLAVE_CONF_TYPE_MASK GENMASK(11, 4)
36#define FSI_SLAVE_CONF_TYPE_SHIFT 4
37#define FSI_SLAVE_CONF_CRC_SHIFT 4
38#define FSI_SLAVE_CONF_CRC_MASK GENMASK(3, 0)
39#define FSI_SLAVE_CONF_DATA_BITS 28
40
41#define FSI_PEEK_BASE 0x410
42
43static const int engine_page_size = 0x400;
44
45#define FSI_SLAVE_BASE 0x800
46
47/*
48 * FSI slave engine control register offsets
49 */
50#define FSI_SMODE 0x0 /* R/W: Mode register */
51#define FSI_SISC 0x8 /* R/W: Interrupt condition */
52#define FSI_SSTAT 0x14 /* R : Slave status */
53#define FSI_LLMODE 0x100 /* R/W: Link layer mode register */
54
55/*
56 * SMODE fields
57 */
58#define FSI_SMODE_WSC 0x80000000 /* Warm start done */
59#define FSI_SMODE_ECRC 0x20000000 /* Hw CRC check */
60#define FSI_SMODE_SID_SHIFT 24 /* ID shift */
61#define FSI_SMODE_SID_MASK 3 /* ID Mask */
62#define FSI_SMODE_ED_SHIFT 20 /* Echo delay shift */
63#define FSI_SMODE_ED_MASK 0xf /* Echo delay mask */
64#define FSI_SMODE_SD_SHIFT 16 /* Send delay shift */
65#define FSI_SMODE_SD_MASK 0xf /* Send delay mask */
66#define FSI_SMODE_LBCRR_SHIFT 8 /* Clk ratio shift */
67#define FSI_SMODE_LBCRR_MASK 0xf /* Clk ratio mask */
68
69/*
70 * LLMODE fields
71 */
72#define FSI_LLMODE_ASYNC 0x1
73
74#define FSI_SLAVE_SIZE_23b 0x800000
75
76static DEFINE_IDA(master_ida);
77
78struct fsi_slave {
79 struct device dev;
80 struct fsi_master *master;
81 struct cdev cdev;
82 int cdev_idx;
83 int id; /* FSI address */
84 int link; /* FSI link# */
85 u32 cfam_id;
86 int chip_id;
87 uint32_t size; /* size of slave address space */
88 u8 t_send_delay;
89 u8 t_echo_delay;
90};
91
92#define to_fsi_master(d) container_of(d, struct fsi_master, dev)
93#define to_fsi_slave(d) container_of(d, struct fsi_slave, dev)
94
95static const int slave_retries = 2;
96static int discard_errors;
97
98static dev_t fsi_base_dev;
99static DEFINE_IDA(fsi_minor_ida);
100#define FSI_CHAR_MAX_DEVICES 0x1000
101
102/* Legacy /dev numbering: 4 devices per chip, 16 chips */
103#define FSI_CHAR_LEGACY_TOP 64
104
105static int fsi_master_read(struct fsi_master *master, int link,
106 uint8_t slave_id, uint32_t addr, void *val, size_t size);
107static int fsi_master_write(struct fsi_master *master, int link,
108 uint8_t slave_id, uint32_t addr, const void *val, size_t size);
109static int fsi_master_break(struct fsi_master *master, int link);
110
111/*
112 * fsi_device_read() / fsi_device_write() / fsi_device_peek()
113 *
114 * FSI endpoint-device support
115 *
116 * Read / write / peek accessors for a client
117 *
118 * Parameters:
119 * dev: Structure passed to FSI client device drivers on probe().
120 * addr: FSI address of given device. Client should pass in its base address
121 * plus desired offset to access its register space.
122 * val: For read/peek this is the value read at the specified address. For
123 * write this is value to write to the specified address.
124 * The data in val must be FSI bus endian (big endian).
125 * size: Size in bytes of the operation. Sizes supported are 1, 2 and 4 bytes.
126 * Addresses must be aligned on size boundaries or an error will result.
127 */
128int fsi_device_read(struct fsi_device *dev, uint32_t addr, void *val,
129 size_t size)
130{
131 if (addr > dev->size || size > dev->size || addr > dev->size - size)
132 return -EINVAL;
133
134 return fsi_slave_read(dev->slave, dev->addr + addr, val, size);
135}
136EXPORT_SYMBOL_GPL(fsi_device_read);
137
138int fsi_device_write(struct fsi_device *dev, uint32_t addr, const void *val,
139 size_t size)
140{
141 if (addr > dev->size || size > dev->size || addr > dev->size - size)
142 return -EINVAL;
143
144 return fsi_slave_write(dev->slave, dev->addr + addr, val, size);
145}
146EXPORT_SYMBOL_GPL(fsi_device_write);
147
148int fsi_device_peek(struct fsi_device *dev, void *val)
149{
150 uint32_t addr = FSI_PEEK_BASE + ((dev->unit - 2) * sizeof(uint32_t));
151
152 return fsi_slave_read(dev->slave, addr, val, sizeof(uint32_t));
153}
154
155static void fsi_device_release(struct device *_device)
156{
157 struct fsi_device *device = to_fsi_dev(_device);
158
159 of_node_put(device->dev.of_node);
160 kfree(device);
161}
162
163static struct fsi_device *fsi_create_device(struct fsi_slave *slave)
164{
165 struct fsi_device *dev;
166
167 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
168 if (!dev)
169 return NULL;
170
171 dev->dev.parent = &slave->dev;
172 dev->dev.bus = &fsi_bus_type;
173 dev->dev.release = fsi_device_release;
174
175 return dev;
176}
177
178/* FSI slave support */
179static int fsi_slave_calc_addr(struct fsi_slave *slave, uint32_t *addrp,
180 uint8_t *idp)
181{
182 uint32_t addr = *addrp;
183 uint8_t id = *idp;
184
185 if (addr > slave->size)
186 return -EINVAL;
187
188 /* For 23 bit addressing, we encode the extra two bits in the slave
189 * id (and the slave's actual ID needs to be 0).
190 */
191 if (addr > 0x1fffff) {
192 if (slave->id != 0)
193 return -EINVAL;
194 id = (addr >> 21) & 0x3;
195 addr &= 0x1fffff;
196 }
197
198 *addrp = addr;
199 *idp = id;
200 return 0;
201}
202
203static int fsi_slave_report_and_clear_errors(struct fsi_slave *slave)
204{
205 struct fsi_master *master = slave->master;
206 __be32 irq, stat;
207 int rc, link;
208 uint8_t id;
209
210 link = slave->link;
211 id = slave->id;
212
213 rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SISC,
214 &irq, sizeof(irq));
215 if (rc)
216 return rc;
217
218 rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SSTAT,
219 &stat, sizeof(stat));
220 if (rc)
221 return rc;
222
223 dev_dbg(&slave->dev, "status: 0x%08x, sisc: 0x%08x\n",
224 be32_to_cpu(stat), be32_to_cpu(irq));
225
226 /* clear interrupts */
227 return fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SISC,
228 &irq, sizeof(irq));
229}
230
231/* Encode slave local bus echo delay */
232static inline uint32_t fsi_smode_echodly(int x)
233{
234 return (x & FSI_SMODE_ED_MASK) << FSI_SMODE_ED_SHIFT;
235}
236
237/* Encode slave local bus send delay */
238static inline uint32_t fsi_smode_senddly(int x)
239{
240 return (x & FSI_SMODE_SD_MASK) << FSI_SMODE_SD_SHIFT;
241}
242
243/* Encode slave local bus clock rate ratio */
244static inline uint32_t fsi_smode_lbcrr(int x)
245{
246 return (x & FSI_SMODE_LBCRR_MASK) << FSI_SMODE_LBCRR_SHIFT;
247}
248
249/* Encode slave ID */
250static inline uint32_t fsi_smode_sid(int x)
251{
252 return (x & FSI_SMODE_SID_MASK) << FSI_SMODE_SID_SHIFT;
253}
254
255static uint32_t fsi_slave_smode(int id, u8 t_senddly, u8 t_echodly)
256{
257 return FSI_SMODE_WSC | FSI_SMODE_ECRC
258 | fsi_smode_sid(id)
259 | fsi_smode_echodly(t_echodly - 1) | fsi_smode_senddly(t_senddly - 1)
260 | fsi_smode_lbcrr(0x8);
261}
262
263static int fsi_slave_set_smode(struct fsi_slave *slave)
264{
265 uint32_t smode;
266 __be32 data;
267
268 /* set our smode register with the slave ID field to 0; this enables
269 * extended slave addressing
270 */
271 smode = fsi_slave_smode(slave->id, slave->t_send_delay, slave->t_echo_delay);
272 data = cpu_to_be32(smode);
273
274 return fsi_master_write(slave->master, slave->link, slave->id,
275 FSI_SLAVE_BASE + FSI_SMODE,
276 &data, sizeof(data));
277}
278
279static int fsi_slave_handle_error(struct fsi_slave *slave, bool write,
280 uint32_t addr, size_t size)
281{
282 struct fsi_master *master = slave->master;
283 int rc, link;
284 uint32_t reg;
285 uint8_t id, send_delay, echo_delay;
286
287 if (discard_errors)
288 return -1;
289
290 link = slave->link;
291 id = slave->id;
292
293 dev_dbg(&slave->dev, "handling error on %s to 0x%08x[%zd]",
294 write ? "write" : "read", addr, size);
295
296 /* try a simple clear of error conditions, which may fail if we've lost
297 * communication with the slave
298 */
299 rc = fsi_slave_report_and_clear_errors(slave);
300 if (!rc)
301 return 0;
302
303 /* send a TERM and retry */
304 if (master->term) {
305 rc = master->term(master, link, id);
306 if (!rc) {
307 rc = fsi_master_read(master, link, id, 0,
308 ®, sizeof(reg));
309 if (!rc)
310 rc = fsi_slave_report_and_clear_errors(slave);
311 if (!rc)
312 return 0;
313 }
314 }
315
316 send_delay = slave->t_send_delay;
317 echo_delay = slave->t_echo_delay;
318
319 /* getting serious, reset the slave via BREAK */
320 rc = fsi_master_break(master, link);
321 if (rc)
322 return rc;
323
324 slave->t_send_delay = send_delay;
325 slave->t_echo_delay = echo_delay;
326
327 rc = fsi_slave_set_smode(slave);
328 if (rc)
329 return rc;
330
331 if (master->link_config)
332 master->link_config(master, link,
333 slave->t_send_delay,
334 slave->t_echo_delay);
335
336 return fsi_slave_report_and_clear_errors(slave);
337}
338
339int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
340 void *val, size_t size)
341{
342 uint8_t id = slave->id;
343 int rc, err_rc, i;
344
345 rc = fsi_slave_calc_addr(slave, &addr, &id);
346 if (rc)
347 return rc;
348
349 for (i = 0; i < slave_retries; i++) {
350 rc = fsi_master_read(slave->master, slave->link,
351 id, addr, val, size);
352 if (!rc)
353 break;
354
355 err_rc = fsi_slave_handle_error(slave, false, addr, size);
356 if (err_rc)
357 break;
358 }
359
360 return rc;
361}
362EXPORT_SYMBOL_GPL(fsi_slave_read);
363
364int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
365 const void *val, size_t size)
366{
367 uint8_t id = slave->id;
368 int rc, err_rc, i;
369
370 rc = fsi_slave_calc_addr(slave, &addr, &id);
371 if (rc)
372 return rc;
373
374 for (i = 0; i < slave_retries; i++) {
375 rc = fsi_master_write(slave->master, slave->link,
376 id, addr, val, size);
377 if (!rc)
378 break;
379
380 err_rc = fsi_slave_handle_error(slave, true, addr, size);
381 if (err_rc)
382 break;
383 }
384
385 return rc;
386}
387EXPORT_SYMBOL_GPL(fsi_slave_write);
388
389extern int fsi_slave_claim_range(struct fsi_slave *slave,
390 uint32_t addr, uint32_t size)
391{
392 if (addr + size < addr)
393 return -EINVAL;
394
395 if (addr + size > slave->size)
396 return -EINVAL;
397
398 /* todo: check for overlapping claims */
399 return 0;
400}
401EXPORT_SYMBOL_GPL(fsi_slave_claim_range);
402
403extern void fsi_slave_release_range(struct fsi_slave *slave,
404 uint32_t addr, uint32_t size)
405{
406}
407EXPORT_SYMBOL_GPL(fsi_slave_release_range);
408
409static bool fsi_device_node_matches(struct device *dev, struct device_node *np,
410 uint32_t addr, uint32_t size)
411{
412 unsigned int len, na, ns;
413 const __be32 *prop;
414 uint32_t psize;
415
416 na = of_n_addr_cells(np);
417 ns = of_n_size_cells(np);
418
419 if (na != 1 || ns != 1)
420 return false;
421
422 prop = of_get_property(np, "reg", &len);
423 if (!prop || len != 8)
424 return false;
425
426 if (of_read_number(prop, 1) != addr)
427 return false;
428
429 psize = of_read_number(prop + 1, 1);
430 if (psize != size) {
431 dev_warn(dev,
432 "node %s matches probed address, but not size (got 0x%x, expected 0x%x)",
433 of_node_full_name(np), psize, size);
434 }
435
436 return true;
437}
438
439/* Find a matching node for the slave engine at @address, using @size bytes
440 * of space. Returns NULL if not found, or a matching node with refcount
441 * already incremented.
442 */
443static struct device_node *fsi_device_find_of_node(struct fsi_device *dev)
444{
445 struct device_node *parent, *np;
446
447 parent = dev_of_node(&dev->slave->dev);
448 if (!parent)
449 return NULL;
450
451 for_each_child_of_node(parent, np) {
452 if (fsi_device_node_matches(&dev->dev, np,
453 dev->addr, dev->size))
454 return np;
455 }
456
457 return NULL;
458}
459
460static int fsi_slave_scan(struct fsi_slave *slave)
461{
462 uint32_t engine_addr;
463 int rc, i;
464
465 /*
466 * scan engines
467 *
468 * We keep the peek mode and slave engines for the core; so start
469 * at the third slot in the configuration table. We also need to
470 * skip the chip ID entry at the start of the address space.
471 */
472 engine_addr = engine_page_size * 3;
473 for (i = 2; i < engine_page_size / sizeof(uint32_t); i++) {
474 uint8_t slots, version, type, crc;
475 struct fsi_device *dev;
476 uint32_t conf;
477 __be32 data;
478
479 rc = fsi_slave_read(slave, (i + 1) * sizeof(data),
480 &data, sizeof(data));
481 if (rc) {
482 dev_warn(&slave->dev,
483 "error reading slave registers\n");
484 return -1;
485 }
486 conf = be32_to_cpu(data);
487
488 crc = crc4(0, conf, 32);
489 if (crc) {
490 dev_warn(&slave->dev,
491 "crc error in slave register at 0x%04x\n",
492 i);
493 return -1;
494 }
495
496 slots = (conf & FSI_SLAVE_CONF_SLOTS_MASK)
497 >> FSI_SLAVE_CONF_SLOTS_SHIFT;
498 version = (conf & FSI_SLAVE_CONF_VERSION_MASK)
499 >> FSI_SLAVE_CONF_VERSION_SHIFT;
500 type = (conf & FSI_SLAVE_CONF_TYPE_MASK)
501 >> FSI_SLAVE_CONF_TYPE_SHIFT;
502
503 /*
504 * Unused address areas are marked by a zero type value; this
505 * skips the defined address areas
506 */
507 if (type != 0 && slots != 0) {
508
509 /* create device */
510 dev = fsi_create_device(slave);
511 if (!dev)
512 return -ENOMEM;
513
514 dev->slave = slave;
515 dev->engine_type = type;
516 dev->version = version;
517 dev->unit = i;
518 dev->addr = engine_addr;
519 dev->size = slots * engine_page_size;
520
521 dev_dbg(&slave->dev,
522 "engine[%i]: type %x, version %x, addr %x size %x\n",
523 dev->unit, dev->engine_type, version,
524 dev->addr, dev->size);
525
526 dev_set_name(&dev->dev, "%02x:%02x:%02x:%02x",
527 slave->master->idx, slave->link,
528 slave->id, i - 2);
529 dev->dev.of_node = fsi_device_find_of_node(dev);
530
531 rc = device_register(&dev->dev);
532 if (rc) {
533 dev_warn(&slave->dev, "add failed: %d\n", rc);
534 put_device(&dev->dev);
535 }
536 }
537
538 engine_addr += slots * engine_page_size;
539
540 if (!(conf & FSI_SLAVE_CONF_NEXT_MASK))
541 break;
542 }
543
544 return 0;
545}
546
547static ssize_t fsi_slave_sysfs_raw_read(struct file *file,
548 struct kobject *kobj, struct bin_attribute *attr, char *buf,
549 loff_t off, size_t count)
550{
551 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
552 size_t total_len, read_len;
553 int rc;
554
555 if (off < 0)
556 return -EINVAL;
557
558 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
559 return -EINVAL;
560
561 for (total_len = 0; total_len < count; total_len += read_len) {
562 read_len = min_t(size_t, count, 4);
563 read_len -= off & 0x3;
564
565 rc = fsi_slave_read(slave, off, buf + total_len, read_len);
566 if (rc)
567 return rc;
568
569 off += read_len;
570 }
571
572 return count;
573}
574
575static ssize_t fsi_slave_sysfs_raw_write(struct file *file,
576 struct kobject *kobj, struct bin_attribute *attr,
577 char *buf, loff_t off, size_t count)
578{
579 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
580 size_t total_len, write_len;
581 int rc;
582
583 if (off < 0)
584 return -EINVAL;
585
586 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
587 return -EINVAL;
588
589 for (total_len = 0; total_len < count; total_len += write_len) {
590 write_len = min_t(size_t, count, 4);
591 write_len -= off & 0x3;
592
593 rc = fsi_slave_write(slave, off, buf + total_len, write_len);
594 if (rc)
595 return rc;
596
597 off += write_len;
598 }
599
600 return count;
601}
602
603static const struct bin_attribute fsi_slave_raw_attr = {
604 .attr = {
605 .name = "raw",
606 .mode = 0600,
607 },
608 .size = 0,
609 .read = fsi_slave_sysfs_raw_read,
610 .write = fsi_slave_sysfs_raw_write,
611};
612
613static void fsi_slave_release(struct device *dev)
614{
615 struct fsi_slave *slave = to_fsi_slave(dev);
616
617 fsi_free_minor(slave->dev.devt);
618 of_node_put(dev->of_node);
619 kfree(slave);
620}
621
622static bool fsi_slave_node_matches(struct device_node *np,
623 int link, uint8_t id)
624{
625 unsigned int len, na, ns;
626 const __be32 *prop;
627
628 na = of_n_addr_cells(np);
629 ns = of_n_size_cells(np);
630
631 /* Ensure we have the correct format for addresses and sizes in
632 * reg properties
633 */
634 if (na != 2 || ns != 0)
635 return false;
636
637 prop = of_get_property(np, "reg", &len);
638 if (!prop || len != 8)
639 return false;
640
641 return (of_read_number(prop, 1) == link) &&
642 (of_read_number(prop + 1, 1) == id);
643}
644
645/* Find a matching node for the slave at (link, id). Returns NULL if none
646 * found, or a matching node with refcount already incremented.
647 */
648static struct device_node *fsi_slave_find_of_node(struct fsi_master *master,
649 int link, uint8_t id)
650{
651 struct device_node *parent, *np;
652
653 parent = dev_of_node(&master->dev);
654 if (!parent)
655 return NULL;
656
657 for_each_child_of_node(parent, np) {
658 if (fsi_slave_node_matches(np, link, id))
659 return np;
660 }
661
662 return NULL;
663}
664
665static ssize_t cfam_read(struct file *filep, char __user *buf, size_t count,
666 loff_t *offset)
667{
668 struct fsi_slave *slave = filep->private_data;
669 size_t total_len, read_len;
670 loff_t off = *offset;
671 ssize_t rc;
672
673 if (off < 0)
674 return -EINVAL;
675
676 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
677 return -EINVAL;
678
679 for (total_len = 0; total_len < count; total_len += read_len) {
680 __be32 data;
681
682 read_len = min_t(size_t, count, 4);
683 read_len -= off & 0x3;
684
685 rc = fsi_slave_read(slave, off, &data, read_len);
686 if (rc)
687 goto fail;
688 rc = copy_to_user(buf + total_len, &data, read_len);
689 if (rc) {
690 rc = -EFAULT;
691 goto fail;
692 }
693 off += read_len;
694 }
695 rc = count;
696 fail:
697 *offset = off;
698 return count;
699}
700
701static ssize_t cfam_write(struct file *filep, const char __user *buf,
702 size_t count, loff_t *offset)
703{
704 struct fsi_slave *slave = filep->private_data;
705 size_t total_len, write_len;
706 loff_t off = *offset;
707 ssize_t rc;
708
709
710 if (off < 0)
711 return -EINVAL;
712
713 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
714 return -EINVAL;
715
716 for (total_len = 0; total_len < count; total_len += write_len) {
717 __be32 data;
718
719 write_len = min_t(size_t, count, 4);
720 write_len -= off & 0x3;
721
722 rc = copy_from_user(&data, buf + total_len, write_len);
723 if (rc) {
724 rc = -EFAULT;
725 goto fail;
726 }
727 rc = fsi_slave_write(slave, off, &data, write_len);
728 if (rc)
729 goto fail;
730 off += write_len;
731 }
732 rc = count;
733 fail:
734 *offset = off;
735 return count;
736}
737
738static loff_t cfam_llseek(struct file *file, loff_t offset, int whence)
739{
740 switch (whence) {
741 case SEEK_CUR:
742 break;
743 case SEEK_SET:
744 file->f_pos = offset;
745 break;
746 default:
747 return -EINVAL;
748 }
749
750 return offset;
751}
752
753static int cfam_open(struct inode *inode, struct file *file)
754{
755 struct fsi_slave *slave = container_of(inode->i_cdev, struct fsi_slave, cdev);
756
757 file->private_data = slave;
758
759 return 0;
760}
761
762static const struct file_operations cfam_fops = {
763 .owner = THIS_MODULE,
764 .open = cfam_open,
765 .llseek = cfam_llseek,
766 .read = cfam_read,
767 .write = cfam_write,
768};
769
770static ssize_t send_term_store(struct device *dev,
771 struct device_attribute *attr,
772 const char *buf, size_t count)
773{
774 struct fsi_slave *slave = to_fsi_slave(dev);
775 struct fsi_master *master = slave->master;
776
777 if (!master->term)
778 return -ENODEV;
779
780 master->term(master, slave->link, slave->id);
781 return count;
782}
783
784static DEVICE_ATTR_WO(send_term);
785
786static ssize_t slave_send_echo_show(struct device *dev,
787 struct device_attribute *attr,
788 char *buf)
789{
790 struct fsi_slave *slave = to_fsi_slave(dev);
791
792 return sprintf(buf, "%u\n", slave->t_send_delay);
793}
794
795static ssize_t slave_send_echo_store(struct device *dev,
796 struct device_attribute *attr, const char *buf, size_t count)
797{
798 struct fsi_slave *slave = to_fsi_slave(dev);
799 struct fsi_master *master = slave->master;
800 unsigned long val;
801 int rc;
802
803 if (kstrtoul(buf, 0, &val) < 0)
804 return -EINVAL;
805
806 if (val < 1 || val > 16)
807 return -EINVAL;
808
809 if (!master->link_config)
810 return -ENXIO;
811
812 /* Current HW mandates that send and echo delay are identical */
813 slave->t_send_delay = val;
814 slave->t_echo_delay = val;
815
816 rc = fsi_slave_set_smode(slave);
817 if (rc < 0)
818 return rc;
819 if (master->link_config)
820 master->link_config(master, slave->link,
821 slave->t_send_delay,
822 slave->t_echo_delay);
823
824 return count;
825}
826
827static DEVICE_ATTR(send_echo_delays, 0600,
828 slave_send_echo_show, slave_send_echo_store);
829
830static ssize_t chip_id_show(struct device *dev,
831 struct device_attribute *attr,
832 char *buf)
833{
834 struct fsi_slave *slave = to_fsi_slave(dev);
835
836 return sprintf(buf, "%d\n", slave->chip_id);
837}
838
839static DEVICE_ATTR_RO(chip_id);
840
841static ssize_t cfam_id_show(struct device *dev,
842 struct device_attribute *attr,
843 char *buf)
844{
845 struct fsi_slave *slave = to_fsi_slave(dev);
846
847 return sprintf(buf, "0x%x\n", slave->cfam_id);
848}
849
850static DEVICE_ATTR_RO(cfam_id);
851
852static struct attribute *cfam_attr[] = {
853 &dev_attr_send_echo_delays.attr,
854 &dev_attr_chip_id.attr,
855 &dev_attr_cfam_id.attr,
856 &dev_attr_send_term.attr,
857 NULL,
858};
859
860static const struct attribute_group cfam_attr_group = {
861 .attrs = cfam_attr,
862};
863
864static const struct attribute_group *cfam_attr_groups[] = {
865 &cfam_attr_group,
866 NULL,
867};
868
869static char *cfam_devnode(struct device *dev, umode_t *mode,
870 kuid_t *uid, kgid_t *gid)
871{
872 struct fsi_slave *slave = to_fsi_slave(dev);
873
874#ifdef CONFIG_FSI_NEW_DEV_NODE
875 return kasprintf(GFP_KERNEL, "fsi/cfam%d", slave->cdev_idx);
876#else
877 return kasprintf(GFP_KERNEL, "cfam%d", slave->cdev_idx);
878#endif
879}
880
881static const struct device_type cfam_type = {
882 .name = "cfam",
883 .devnode = cfam_devnode,
884 .groups = cfam_attr_groups
885};
886
887static char *fsi_cdev_devnode(struct device *dev, umode_t *mode,
888 kuid_t *uid, kgid_t *gid)
889{
890#ifdef CONFIG_FSI_NEW_DEV_NODE
891 return kasprintf(GFP_KERNEL, "fsi/%s", dev_name(dev));
892#else
893 return kasprintf(GFP_KERNEL, "%s", dev_name(dev));
894#endif
895}
896
897const struct device_type fsi_cdev_type = {
898 .name = "fsi-cdev",
899 .devnode = fsi_cdev_devnode,
900};
901EXPORT_SYMBOL_GPL(fsi_cdev_type);
902
903/* Backward compatible /dev/ numbering in "old style" mode */
904static int fsi_adjust_index(int index)
905{
906#ifdef CONFIG_FSI_NEW_DEV_NODE
907 return index;
908#else
909 return index + 1;
910#endif
911}
912
913static int __fsi_get_new_minor(struct fsi_slave *slave, enum fsi_dev_type type,
914 dev_t *out_dev, int *out_index)
915{
916 int cid = slave->chip_id;
917 int id;
918
919 /* Check if we qualify for legacy numbering */
920 if (cid >= 0 && cid < 16 && type < 4) {
921 /* Try reserving the legacy number */
922 id = (cid << 4) | type;
923 id = ida_simple_get(&fsi_minor_ida, id, id + 1, GFP_KERNEL);
924 if (id >= 0) {
925 *out_index = fsi_adjust_index(cid);
926 *out_dev = fsi_base_dev + id;
927 return 0;
928 }
929 /* Other failure */
930 if (id != -ENOSPC)
931 return id;
932 /* Fallback to non-legacy allocation */
933 }
934 id = ida_simple_get(&fsi_minor_ida, FSI_CHAR_LEGACY_TOP,
935 FSI_CHAR_MAX_DEVICES, GFP_KERNEL);
936 if (id < 0)
937 return id;
938 *out_index = fsi_adjust_index(id);
939 *out_dev = fsi_base_dev + id;
940 return 0;
941}
942
943int fsi_get_new_minor(struct fsi_device *fdev, enum fsi_dev_type type,
944 dev_t *out_dev, int *out_index)
945{
946 return __fsi_get_new_minor(fdev->slave, type, out_dev, out_index);
947}
948EXPORT_SYMBOL_GPL(fsi_get_new_minor);
949
950void fsi_free_minor(dev_t dev)
951{
952 ida_simple_remove(&fsi_minor_ida, MINOR(dev));
953}
954EXPORT_SYMBOL_GPL(fsi_free_minor);
955
956static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
957{
958 uint32_t cfam_id;
959 struct fsi_slave *slave;
960 uint8_t crc;
961 __be32 data, llmode;
962 int rc;
963
964 /* Currently, we only support single slaves on a link, and use the
965 * full 23-bit address range
966 */
967 if (id != 0)
968 return -EINVAL;
969
970 rc = fsi_master_read(master, link, id, 0, &data, sizeof(data));
971 if (rc) {
972 dev_dbg(&master->dev, "can't read slave %02x:%02x %d\n",
973 link, id, rc);
974 return -ENODEV;
975 }
976 cfam_id = be32_to_cpu(data);
977
978 crc = crc4(0, cfam_id, 32);
979 if (crc) {
980 dev_warn(&master->dev, "slave %02x:%02x invalid cfam id CRC!\n",
981 link, id);
982 return -EIO;
983 }
984
985 dev_dbg(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n",
986 cfam_id, master->idx, link, id);
987
988 /* If we're behind a master that doesn't provide a self-running bus
989 * clock, put the slave into async mode
990 */
991 if (master->flags & FSI_MASTER_FLAG_SWCLOCK) {
992 llmode = cpu_to_be32(FSI_LLMODE_ASYNC);
993 rc = fsi_master_write(master, link, id,
994 FSI_SLAVE_BASE + FSI_LLMODE,
995 &llmode, sizeof(llmode));
996 if (rc)
997 dev_warn(&master->dev,
998 "can't set llmode on slave:%02x:%02x %d\n",
999 link, id, rc);
1000 }
1001
1002 /* We can communicate with a slave; create the slave device and
1003 * register.
1004 */
1005 slave = kzalloc(sizeof(*slave), GFP_KERNEL);
1006 if (!slave)
1007 return -ENOMEM;
1008
1009 dev_set_name(&slave->dev, "slave@%02x:%02x", link, id);
1010 slave->dev.type = &cfam_type;
1011 slave->dev.parent = &master->dev;
1012 slave->dev.of_node = fsi_slave_find_of_node(master, link, id);
1013 slave->dev.release = fsi_slave_release;
1014 device_initialize(&slave->dev);
1015 slave->cfam_id = cfam_id;
1016 slave->master = master;
1017 slave->link = link;
1018 slave->id = id;
1019 slave->size = FSI_SLAVE_SIZE_23b;
1020 slave->t_send_delay = 16;
1021 slave->t_echo_delay = 16;
1022
1023 /* Get chip ID if any */
1024 slave->chip_id = -1;
1025 if (slave->dev.of_node) {
1026 uint32_t prop;
1027 if (!of_property_read_u32(slave->dev.of_node, "chip-id", &prop))
1028 slave->chip_id = prop;
1029
1030 }
1031
1032 rc = fsi_slave_set_smode(slave);
1033 if (rc) {
1034 dev_warn(&master->dev,
1035 "can't set smode on slave:%02x:%02x %d\n",
1036 link, id, rc);
1037 goto err_free;
1038 }
1039
1040 /* Allocate a minor in the FSI space */
1041 rc = __fsi_get_new_minor(slave, fsi_dev_cfam, &slave->dev.devt,
1042 &slave->cdev_idx);
1043 if (rc)
1044 goto err_free;
1045
1046 /* Create chardev for userspace access */
1047 cdev_init(&slave->cdev, &cfam_fops);
1048 rc = cdev_device_add(&slave->cdev, &slave->dev);
1049 if (rc) {
1050 dev_err(&slave->dev, "Error %d creating slave device\n", rc);
1051 goto err_free_ida;
1052 }
1053
1054 /* Now that we have the cdev registered with the core, any fatal
1055 * failures beyond this point will need to clean up through
1056 * cdev_device_del(). Fortunately though, nothing past here is fatal.
1057 */
1058
1059 if (master->link_config)
1060 master->link_config(master, link,
1061 slave->t_send_delay,
1062 slave->t_echo_delay);
1063
1064 /* Legacy raw file -> to be removed */
1065 rc = device_create_bin_file(&slave->dev, &fsi_slave_raw_attr);
1066 if (rc)
1067 dev_warn(&slave->dev, "failed to create raw attr: %d\n", rc);
1068
1069
1070 rc = fsi_slave_scan(slave);
1071 if (rc)
1072 dev_dbg(&master->dev, "failed during slave scan with: %d\n",
1073 rc);
1074
1075 return 0;
1076
1077err_free_ida:
1078 fsi_free_minor(slave->dev.devt);
1079err_free:
1080 of_node_put(slave->dev.of_node);
1081 kfree(slave);
1082 return rc;
1083}
1084
1085/* FSI master support */
1086static int fsi_check_access(uint32_t addr, size_t size)
1087{
1088 if (size == 4) {
1089 if (addr & 0x3)
1090 return -EINVAL;
1091 } else if (size == 2) {
1092 if (addr & 0x1)
1093 return -EINVAL;
1094 } else if (size != 1)
1095 return -EINVAL;
1096
1097 return 0;
1098}
1099
1100static int fsi_master_read(struct fsi_master *master, int link,
1101 uint8_t slave_id, uint32_t addr, void *val, size_t size)
1102{
1103 int rc;
1104
1105 trace_fsi_master_read(master, link, slave_id, addr, size);
1106
1107 rc = fsi_check_access(addr, size);
1108 if (!rc)
1109 rc = master->read(master, link, slave_id, addr, val, size);
1110
1111 trace_fsi_master_rw_result(master, link, slave_id, addr, size,
1112 false, val, rc);
1113
1114 return rc;
1115}
1116
1117static int fsi_master_write(struct fsi_master *master, int link,
1118 uint8_t slave_id, uint32_t addr, const void *val, size_t size)
1119{
1120 int rc;
1121
1122 trace_fsi_master_write(master, link, slave_id, addr, size, val);
1123
1124 rc = fsi_check_access(addr, size);
1125 if (!rc)
1126 rc = master->write(master, link, slave_id, addr, val, size);
1127
1128 trace_fsi_master_rw_result(master, link, slave_id, addr, size,
1129 true, val, rc);
1130
1131 return rc;
1132}
1133
1134static int fsi_master_link_enable(struct fsi_master *master, int link)
1135{
1136 if (master->link_enable)
1137 return master->link_enable(master, link);
1138
1139 return 0;
1140}
1141
1142/*
1143 * Issue a break command on this link
1144 */
1145static int fsi_master_break(struct fsi_master *master, int link)
1146{
1147 int rc = 0;
1148
1149 trace_fsi_master_break(master, link);
1150
1151 if (master->send_break)
1152 rc = master->send_break(master, link);
1153 if (master->link_config)
1154 master->link_config(master, link, 16, 16);
1155
1156 return rc;
1157}
1158
1159static int fsi_master_scan(struct fsi_master *master)
1160{
1161 int link, rc;
1162
1163 for (link = 0; link < master->n_links; link++) {
1164 rc = fsi_master_link_enable(master, link);
1165 if (rc) {
1166 dev_dbg(&master->dev,
1167 "enable link %d failed: %d\n", link, rc);
1168 continue;
1169 }
1170 rc = fsi_master_break(master, link);
1171 if (rc) {
1172 dev_dbg(&master->dev,
1173 "break to link %d failed: %d\n", link, rc);
1174 continue;
1175 }
1176
1177 fsi_slave_init(master, link, 0);
1178 }
1179
1180 return 0;
1181}
1182
1183static int fsi_slave_remove_device(struct device *dev, void *arg)
1184{
1185 device_unregister(dev);
1186 return 0;
1187}
1188
1189static int fsi_master_remove_slave(struct device *dev, void *arg)
1190{
1191 struct fsi_slave *slave = to_fsi_slave(dev);
1192
1193 device_for_each_child(dev, NULL, fsi_slave_remove_device);
1194 cdev_device_del(&slave->cdev, &slave->dev);
1195 put_device(dev);
1196 return 0;
1197}
1198
1199static void fsi_master_unscan(struct fsi_master *master)
1200{
1201 device_for_each_child(&master->dev, NULL, fsi_master_remove_slave);
1202}
1203
1204int fsi_master_rescan(struct fsi_master *master)
1205{
1206 int rc;
1207
1208 mutex_lock(&master->scan_lock);
1209 fsi_master_unscan(master);
1210 rc = fsi_master_scan(master);
1211 mutex_unlock(&master->scan_lock);
1212
1213 return rc;
1214}
1215EXPORT_SYMBOL_GPL(fsi_master_rescan);
1216
1217static ssize_t master_rescan_store(struct device *dev,
1218 struct device_attribute *attr, const char *buf, size_t count)
1219{
1220 struct fsi_master *master = to_fsi_master(dev);
1221 int rc;
1222
1223 rc = fsi_master_rescan(master);
1224 if (rc < 0)
1225 return rc;
1226
1227 return count;
1228}
1229
1230static DEVICE_ATTR(rescan, 0200, NULL, master_rescan_store);
1231
1232static ssize_t master_break_store(struct device *dev,
1233 struct device_attribute *attr, const char *buf, size_t count)
1234{
1235 struct fsi_master *master = to_fsi_master(dev);
1236
1237 fsi_master_break(master, 0);
1238
1239 return count;
1240}
1241
1242static DEVICE_ATTR(break, 0200, NULL, master_break_store);
1243
1244int fsi_master_register(struct fsi_master *master)
1245{
1246 int rc;
1247 struct device_node *np;
1248
1249 mutex_init(&master->scan_lock);
1250 master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL);
1251 dev_set_name(&master->dev, "fsi%d", master->idx);
1252
1253 rc = device_register(&master->dev);
1254 if (rc) {
1255 ida_simple_remove(&master_ida, master->idx);
1256 return rc;
1257 }
1258
1259 rc = device_create_file(&master->dev, &dev_attr_rescan);
1260 if (rc) {
1261 device_del(&master->dev);
1262 ida_simple_remove(&master_ida, master->idx);
1263 return rc;
1264 }
1265
1266 rc = device_create_file(&master->dev, &dev_attr_break);
1267 if (rc) {
1268 device_del(&master->dev);
1269 ida_simple_remove(&master_ida, master->idx);
1270 return rc;
1271 }
1272
1273 np = dev_of_node(&master->dev);
1274 if (!of_property_read_bool(np, "no-scan-on-init")) {
1275 mutex_lock(&master->scan_lock);
1276 fsi_master_scan(master);
1277 mutex_unlock(&master->scan_lock);
1278 }
1279
1280 return 0;
1281}
1282EXPORT_SYMBOL_GPL(fsi_master_register);
1283
1284void fsi_master_unregister(struct fsi_master *master)
1285{
1286 if (master->idx >= 0) {
1287 ida_simple_remove(&master_ida, master->idx);
1288 master->idx = -1;
1289 }
1290
1291 mutex_lock(&master->scan_lock);
1292 fsi_master_unscan(master);
1293 mutex_unlock(&master->scan_lock);
1294 device_unregister(&master->dev);
1295}
1296EXPORT_SYMBOL_GPL(fsi_master_unregister);
1297
1298/* FSI core & Linux bus type definitions */
1299
1300static int fsi_bus_match(struct device *dev, struct device_driver *drv)
1301{
1302 struct fsi_device *fsi_dev = to_fsi_dev(dev);
1303 struct fsi_driver *fsi_drv = to_fsi_drv(drv);
1304 const struct fsi_device_id *id;
1305
1306 if (!fsi_drv->id_table)
1307 return 0;
1308
1309 for (id = fsi_drv->id_table; id->engine_type; id++) {
1310 if (id->engine_type != fsi_dev->engine_type)
1311 continue;
1312 if (id->version == FSI_VERSION_ANY ||
1313 id->version == fsi_dev->version)
1314 return 1;
1315 }
1316
1317 return 0;
1318}
1319
1320int fsi_driver_register(struct fsi_driver *fsi_drv)
1321{
1322 if (!fsi_drv)
1323 return -EINVAL;
1324 if (!fsi_drv->id_table)
1325 return -EINVAL;
1326
1327 return driver_register(&fsi_drv->drv);
1328}
1329EXPORT_SYMBOL_GPL(fsi_driver_register);
1330
1331void fsi_driver_unregister(struct fsi_driver *fsi_drv)
1332{
1333 driver_unregister(&fsi_drv->drv);
1334}
1335EXPORT_SYMBOL_GPL(fsi_driver_unregister);
1336
1337struct bus_type fsi_bus_type = {
1338 .name = "fsi",
1339 .match = fsi_bus_match,
1340};
1341EXPORT_SYMBOL_GPL(fsi_bus_type);
1342
1343static int __init fsi_init(void)
1344{
1345 int rc;
1346
1347 rc = alloc_chrdev_region(&fsi_base_dev, 0, FSI_CHAR_MAX_DEVICES, "fsi");
1348 if (rc)
1349 return rc;
1350 rc = bus_register(&fsi_bus_type);
1351 if (rc)
1352 goto fail_bus;
1353 return 0;
1354
1355 fail_bus:
1356 unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES);
1357 return rc;
1358}
1359postcore_initcall(fsi_init);
1360
1361static void fsi_exit(void)
1362{
1363 bus_unregister(&fsi_bus_type);
1364 unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES);
1365 ida_destroy(&fsi_minor_ida);
1366}
1367module_exit(fsi_exit);
1368module_param(discard_errors, int, 0664);
1369MODULE_LICENSE("GPL");
1370MODULE_PARM_DESC(discard_errors, "Don't invoke error handling on bus accesses");