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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/of_address.h>
20#include <linux/of_device.h>
21#include <linux/slab.h>
22#include <linux/bitops.h>
23#include <linux/cdev.h>
24#include <linux/fs.h>
25#include <linux/uaccess.h>
26
27#include "fsi-master.h"
28#include "fsi-slave.h"
29
30#define CREATE_TRACE_POINTS
31#include <trace/events/fsi.h>
32
33#define FSI_SLAVE_CONF_NEXT_MASK GENMASK(31, 31)
34#define FSI_SLAVE_CONF_SLOTS_MASK GENMASK(23, 16)
35#define FSI_SLAVE_CONF_SLOTS_SHIFT 16
36#define FSI_SLAVE_CONF_VERSION_MASK GENMASK(15, 12)
37#define FSI_SLAVE_CONF_VERSION_SHIFT 12
38#define FSI_SLAVE_CONF_TYPE_MASK GENMASK(11, 4)
39#define FSI_SLAVE_CONF_TYPE_SHIFT 4
40#define FSI_SLAVE_CONF_CRC_SHIFT 4
41#define FSI_SLAVE_CONF_CRC_MASK GENMASK(3, 0)
42#define FSI_SLAVE_CONF_DATA_BITS 28
43
44#define FSI_PEEK_BASE 0x410
45
46static const int engine_page_size = 0x400;
47
48#define FSI_SLAVE_BASE 0x800
49
50/*
51 * FSI slave engine control register offsets
52 */
53#define FSI_SMODE 0x0 /* R/W: Mode register */
54#define FSI_SISC 0x8 /* R/W: Interrupt condition */
55#define FSI_SSTAT 0x14 /* R : Slave status */
56#define FSI_SLBUS 0x30 /* W : LBUS Ownership */
57#define FSI_LLMODE 0x100 /* R/W: Link layer mode register */
58
59/*
60 * SMODE fields
61 */
62#define FSI_SMODE_WSC 0x80000000 /* Warm start done */
63#define FSI_SMODE_ECRC 0x20000000 /* Hw CRC check */
64#define FSI_SMODE_SID_SHIFT 24 /* ID shift */
65#define FSI_SMODE_SID_MASK 3 /* ID Mask */
66#define FSI_SMODE_ED_SHIFT 20 /* Echo delay shift */
67#define FSI_SMODE_ED_MASK 0xf /* Echo delay mask */
68#define FSI_SMODE_SD_SHIFT 16 /* Send delay shift */
69#define FSI_SMODE_SD_MASK 0xf /* Send delay mask */
70#define FSI_SMODE_LBCRR_SHIFT 8 /* Clk ratio shift */
71#define FSI_SMODE_LBCRR_MASK 0xf /* Clk ratio mask */
72
73/*
74 * SLBUS fields
75 */
76#define FSI_SLBUS_FORCE 0x80000000 /* Force LBUS ownership */
77
78/*
79 * LLMODE fields
80 */
81#define FSI_LLMODE_ASYNC 0x1
82
83#define FSI_SLAVE_SIZE_23b 0x800000
84
85static DEFINE_IDA(master_ida);
86
87static const int slave_retries = 2;
88static int discard_errors;
89
90static dev_t fsi_base_dev;
91static DEFINE_IDA(fsi_minor_ida);
92#define FSI_CHAR_MAX_DEVICES 0x1000
93
94/* Legacy /dev numbering: 4 devices per chip, 16 chips */
95#define FSI_CHAR_LEGACY_TOP 64
96
97static int fsi_master_read(struct fsi_master *master, int link,
98 uint8_t slave_id, uint32_t addr, void *val, size_t size);
99static int fsi_master_write(struct fsi_master *master, int link,
100 uint8_t slave_id, uint32_t addr, const void *val, size_t size);
101static int fsi_master_break(struct fsi_master *master, int link);
102
103/*
104 * fsi_device_read() / fsi_device_write() / fsi_device_peek()
105 *
106 * FSI endpoint-device support
107 *
108 * Read / write / peek accessors for a client
109 *
110 * Parameters:
111 * dev: Structure passed to FSI client device drivers on probe().
112 * addr: FSI address of given device. Client should pass in its base address
113 * plus desired offset to access its register space.
114 * val: For read/peek this is the value read at the specified address. For
115 * write this is value to write to the specified address.
116 * The data in val must be FSI bus endian (big endian).
117 * size: Size in bytes of the operation. Sizes supported are 1, 2 and 4 bytes.
118 * Addresses must be aligned on size boundaries or an error will result.
119 */
120int fsi_device_read(struct fsi_device *dev, uint32_t addr, void *val,
121 size_t size)
122{
123 if (addr > dev->size || size > dev->size || addr > dev->size - size)
124 return -EINVAL;
125
126 return fsi_slave_read(slave: dev->slave, addr: dev->addr + addr, val, size);
127}
128EXPORT_SYMBOL_GPL(fsi_device_read);
129
130int fsi_device_write(struct fsi_device *dev, uint32_t addr, const void *val,
131 size_t size)
132{
133 if (addr > dev->size || size > dev->size || addr > dev->size - size)
134 return -EINVAL;
135
136 return fsi_slave_write(slave: dev->slave, addr: dev->addr + addr, val, size);
137}
138EXPORT_SYMBOL_GPL(fsi_device_write);
139
140int fsi_device_peek(struct fsi_device *dev, void *val)
141{
142 uint32_t addr = FSI_PEEK_BASE + ((dev->unit - 2) * sizeof(uint32_t));
143
144 return fsi_slave_read(slave: dev->slave, addr, val, size: sizeof(uint32_t));
145}
146
147static void fsi_device_release(struct device *_device)
148{
149 struct fsi_device *device = to_fsi_dev(_device);
150
151 of_node_put(node: device->dev.of_node);
152 kfree(objp: device);
153}
154
155static struct fsi_device *fsi_create_device(struct fsi_slave *slave)
156{
157 struct fsi_device *dev;
158
159 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
160 if (!dev)
161 return NULL;
162
163 dev->dev.parent = &slave->dev;
164 dev->dev.bus = &fsi_bus_type;
165 dev->dev.release = fsi_device_release;
166
167 return dev;
168}
169
170/* FSI slave support */
171static int fsi_slave_calc_addr(struct fsi_slave *slave, uint32_t *addrp,
172 uint8_t *idp)
173{
174 uint32_t addr = *addrp;
175 uint8_t id = *idp;
176
177 if (addr > slave->size)
178 return -EINVAL;
179
180 /* For 23 bit addressing, we encode the extra two bits in the slave
181 * id (and the slave's actual ID needs to be 0).
182 */
183 if (addr > 0x1fffff) {
184 if (slave->id != 0)
185 return -EINVAL;
186 id = (addr >> 21) & 0x3;
187 addr &= 0x1fffff;
188 }
189
190 *addrp = addr;
191 *idp = id;
192 return 0;
193}
194
195static int fsi_slave_report_and_clear_errors(struct fsi_slave *slave)
196{
197 struct fsi_master *master = slave->master;
198 __be32 irq, stat;
199 int rc, link;
200 uint8_t id;
201
202 link = slave->link;
203 id = slave->id;
204
205 rc = fsi_master_read(master, link, slave_id: id, FSI_SLAVE_BASE + FSI_SISC,
206 val: &irq, size: sizeof(irq));
207 if (rc)
208 return rc;
209
210 rc = fsi_master_read(master, link, slave_id: id, FSI_SLAVE_BASE + FSI_SSTAT,
211 val: &stat, size: sizeof(stat));
212 if (rc)
213 return rc;
214
215 dev_dbg(&slave->dev, "status: 0x%08x, sisc: 0x%08x\n",
216 be32_to_cpu(stat), be32_to_cpu(irq));
217
218 /* clear interrupts */
219 return fsi_master_write(master, link, slave_id: id, FSI_SLAVE_BASE + FSI_SISC,
220 val: &irq, size: sizeof(irq));
221}
222
223/* Encode slave local bus echo delay */
224static inline uint32_t fsi_smode_echodly(int x)
225{
226 return (x & FSI_SMODE_ED_MASK) << FSI_SMODE_ED_SHIFT;
227}
228
229/* Encode slave local bus send delay */
230static inline uint32_t fsi_smode_senddly(int x)
231{
232 return (x & FSI_SMODE_SD_MASK) << FSI_SMODE_SD_SHIFT;
233}
234
235/* Encode slave local bus clock rate ratio */
236static inline uint32_t fsi_smode_lbcrr(int x)
237{
238 return (x & FSI_SMODE_LBCRR_MASK) << FSI_SMODE_LBCRR_SHIFT;
239}
240
241/* Encode slave ID */
242static inline uint32_t fsi_smode_sid(int x)
243{
244 return (x & FSI_SMODE_SID_MASK) << FSI_SMODE_SID_SHIFT;
245}
246
247static uint32_t fsi_slave_smode(int id, u8 t_senddly, u8 t_echodly)
248{
249 return FSI_SMODE_WSC | FSI_SMODE_ECRC
250 | fsi_smode_sid(x: id)
251 | fsi_smode_echodly(x: t_echodly - 1) | fsi_smode_senddly(x: t_senddly - 1)
252 | fsi_smode_lbcrr(x: 0x8);
253}
254
255static int fsi_slave_set_smode(struct fsi_slave *slave)
256{
257 uint32_t smode;
258 __be32 data;
259
260 /* set our smode register with the slave ID field to 0; this enables
261 * extended slave addressing
262 */
263 smode = fsi_slave_smode(id: slave->id, t_senddly: slave->t_send_delay, t_echodly: slave->t_echo_delay);
264 data = cpu_to_be32(smode);
265
266 return fsi_master_write(master: slave->master, link: slave->link, slave_id: slave->id,
267 FSI_SLAVE_BASE + FSI_SMODE,
268 val: &data, size: sizeof(data));
269}
270
271static int fsi_slave_handle_error(struct fsi_slave *slave, bool write,
272 uint32_t addr, size_t size)
273{
274 struct fsi_master *master = slave->master;
275 int rc, link;
276 uint32_t reg;
277 uint8_t id, send_delay, echo_delay;
278
279 if (discard_errors)
280 return -1;
281
282 link = slave->link;
283 id = slave->id;
284
285 dev_dbg(&slave->dev, "handling error on %s to 0x%08x[%zd]",
286 write ? "write" : "read", addr, size);
287
288 /* try a simple clear of error conditions, which may fail if we've lost
289 * communication with the slave
290 */
291 rc = fsi_slave_report_and_clear_errors(slave);
292 if (!rc)
293 return 0;
294
295 /* send a TERM and retry */
296 if (master->term) {
297 rc = master->term(master, link, id);
298 if (!rc) {
299 rc = fsi_master_read(master, link, slave_id: id, addr: 0,
300 val: &reg, size: sizeof(reg));
301 if (!rc)
302 rc = fsi_slave_report_and_clear_errors(slave);
303 if (!rc)
304 return 0;
305 }
306 }
307
308 send_delay = slave->t_send_delay;
309 echo_delay = slave->t_echo_delay;
310
311 /* getting serious, reset the slave via BREAK */
312 rc = fsi_master_break(master, link);
313 if (rc)
314 return rc;
315
316 slave->t_send_delay = send_delay;
317 slave->t_echo_delay = echo_delay;
318
319 rc = fsi_slave_set_smode(slave);
320 if (rc)
321 return rc;
322
323 if (master->link_config)
324 master->link_config(master, link,
325 slave->t_send_delay,
326 slave->t_echo_delay);
327
328 return fsi_slave_report_and_clear_errors(slave);
329}
330
331int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
332 void *val, size_t size)
333{
334 uint8_t id = slave->id;
335 int rc, err_rc, i;
336
337 rc = fsi_slave_calc_addr(slave, addrp: &addr, idp: &id);
338 if (rc)
339 return rc;
340
341 for (i = 0; i < slave_retries; i++) {
342 rc = fsi_master_read(master: slave->master, link: slave->link,
343 slave_id: id, addr, val, size);
344 if (!rc)
345 break;
346
347 err_rc = fsi_slave_handle_error(slave, write: false, addr, size);
348 if (err_rc)
349 break;
350 }
351
352 return rc;
353}
354EXPORT_SYMBOL_GPL(fsi_slave_read);
355
356int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
357 const void *val, size_t size)
358{
359 uint8_t id = slave->id;
360 int rc, err_rc, i;
361
362 rc = fsi_slave_calc_addr(slave, addrp: &addr, idp: &id);
363 if (rc)
364 return rc;
365
366 for (i = 0; i < slave_retries; i++) {
367 rc = fsi_master_write(master: slave->master, link: slave->link,
368 slave_id: id, addr, val, size);
369 if (!rc)
370 break;
371
372 err_rc = fsi_slave_handle_error(slave, write: true, addr, size);
373 if (err_rc)
374 break;
375 }
376
377 return rc;
378}
379EXPORT_SYMBOL_GPL(fsi_slave_write);
380
381int fsi_slave_claim_range(struct fsi_slave *slave,
382 uint32_t addr, uint32_t size)
383{
384 if (addr + size < addr)
385 return -EINVAL;
386
387 if (addr + size > slave->size)
388 return -EINVAL;
389
390 /* todo: check for overlapping claims */
391 return 0;
392}
393EXPORT_SYMBOL_GPL(fsi_slave_claim_range);
394
395void fsi_slave_release_range(struct fsi_slave *slave,
396 uint32_t addr, uint32_t size)
397{
398}
399EXPORT_SYMBOL_GPL(fsi_slave_release_range);
400
401static bool fsi_device_node_matches(struct device *dev, struct device_node *np,
402 uint32_t addr, uint32_t size)
403{
404 u64 paddr, psize;
405
406 if (of_property_read_reg(np, idx: 0, addr: &paddr, size: &psize))
407 return false;
408
409 if (paddr != addr)
410 return false;
411
412 if (psize != size) {
413 dev_warn(dev,
414 "node %pOF matches probed address, but not size (got 0x%llx, expected 0x%x)",
415 np, psize, size);
416 }
417
418 return true;
419}
420
421/* Find a matching node for the slave engine at @address, using @size bytes
422 * of space. Returns NULL if not found, or a matching node with refcount
423 * already incremented.
424 */
425static struct device_node *fsi_device_find_of_node(struct fsi_device *dev)
426{
427 struct device_node *parent, *np;
428
429 parent = dev_of_node(dev: &dev->slave->dev);
430 if (!parent)
431 return NULL;
432
433 for_each_child_of_node(parent, np) {
434 if (fsi_device_node_matches(dev: &dev->dev, np,
435 addr: dev->addr, size: dev->size))
436 return np;
437 }
438
439 return NULL;
440}
441
442static int fsi_slave_scan(struct fsi_slave *slave)
443{
444 uint32_t engine_addr;
445 int rc, i;
446
447 /*
448 * scan engines
449 *
450 * We keep the peek mode and slave engines for the core; so start
451 * at the third slot in the configuration table. We also need to
452 * skip the chip ID entry at the start of the address space.
453 */
454 engine_addr = engine_page_size * 3;
455 for (i = 2; i < engine_page_size / sizeof(uint32_t); i++) {
456 uint8_t slots, version, type, crc;
457 struct fsi_device *dev;
458 uint32_t conf;
459 __be32 data;
460
461 rc = fsi_slave_read(slave, (i + 1) * sizeof(data),
462 &data, sizeof(data));
463 if (rc) {
464 dev_warn(&slave->dev,
465 "error reading slave registers\n");
466 return -1;
467 }
468 conf = be32_to_cpu(data);
469
470 crc = crc4(c: 0, x: conf, bits: 32);
471 if (crc) {
472 dev_warn(&slave->dev,
473 "crc error in slave register at 0x%04x\n",
474 i);
475 return -1;
476 }
477
478 slots = (conf & FSI_SLAVE_CONF_SLOTS_MASK)
479 >> FSI_SLAVE_CONF_SLOTS_SHIFT;
480 version = (conf & FSI_SLAVE_CONF_VERSION_MASK)
481 >> FSI_SLAVE_CONF_VERSION_SHIFT;
482 type = (conf & FSI_SLAVE_CONF_TYPE_MASK)
483 >> FSI_SLAVE_CONF_TYPE_SHIFT;
484
485 /*
486 * Unused address areas are marked by a zero type value; this
487 * skips the defined address areas
488 */
489 if (type != 0 && slots != 0) {
490
491 /* create device */
492 dev = fsi_create_device(slave);
493 if (!dev)
494 return -ENOMEM;
495
496 dev->slave = slave;
497 dev->engine_type = type;
498 dev->version = version;
499 dev->unit = i;
500 dev->addr = engine_addr;
501 dev->size = slots * engine_page_size;
502
503 trace_fsi_dev_init(dev);
504
505 dev_dbg(&slave->dev,
506 "engine[%i]: type %x, version %x, addr %x size %x\n",
507 dev->unit, dev->engine_type, version,
508 dev->addr, dev->size);
509
510 dev_set_name(dev: &dev->dev, name: "%02x:%02x:%02x:%02x",
511 slave->master->idx, slave->link,
512 slave->id, i - 2);
513 dev->dev.of_node = fsi_device_find_of_node(dev);
514
515 rc = device_register(dev: &dev->dev);
516 if (rc) {
517 dev_warn(&slave->dev, "add failed: %d\n", rc);
518 put_device(dev: &dev->dev);
519 }
520 }
521
522 engine_addr += slots * engine_page_size;
523
524 if (!(conf & FSI_SLAVE_CONF_NEXT_MASK))
525 break;
526 }
527
528 return 0;
529}
530
531static unsigned long aligned_access_size(size_t offset, size_t count)
532{
533 unsigned long offset_unit, count_unit;
534
535 /* Criteria:
536 *
537 * 1. Access size must be less than or equal to the maximum access
538 * width or the highest power-of-two factor of offset
539 * 2. Access size must be less than or equal to the amount specified by
540 * count
541 *
542 * The access width is optimal if we can calculate 1 to be strictly
543 * equal while still satisfying 2.
544 */
545
546 /* Find 1 by the bottom bit of offset (with a 4 byte access cap) */
547 offset_unit = BIT(__builtin_ctzl(offset | 4));
548
549 /* Find 2 by the top bit of count */
550 count_unit = BIT(8 * sizeof(unsigned long) - 1 - __builtin_clzl(count));
551
552 /* Constrain the maximum access width to the minimum of both criteria */
553 return BIT(__builtin_ctzl(offset_unit | count_unit));
554}
555
556static ssize_t fsi_slave_sysfs_raw_read(struct file *file,
557 struct kobject *kobj, const struct bin_attribute *attr, char *buf,
558 loff_t off, size_t count)
559{
560 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
561 size_t total_len, read_len;
562 int rc;
563
564 if (off < 0)
565 return -EINVAL;
566
567 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
568 return -EINVAL;
569
570 for (total_len = 0; total_len < count; total_len += read_len) {
571 read_len = aligned_access_size(offset: off, count: count - total_len);
572
573 rc = fsi_slave_read(slave, off, buf + total_len, read_len);
574 if (rc)
575 return rc;
576
577 off += read_len;
578 }
579
580 return count;
581}
582
583static ssize_t fsi_slave_sysfs_raw_write(struct file *file,
584 struct kobject *kobj, const struct bin_attribute *attr,
585 char *buf, loff_t off, size_t count)
586{
587 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
588 size_t total_len, write_len;
589 int rc;
590
591 if (off < 0)
592 return -EINVAL;
593
594 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
595 return -EINVAL;
596
597 for (total_len = 0; total_len < count; total_len += write_len) {
598 write_len = aligned_access_size(offset: off, count: count - total_len);
599
600 rc = fsi_slave_write(slave, off, buf + total_len, write_len);
601 if (rc)
602 return rc;
603
604 off += write_len;
605 }
606
607 return count;
608}
609
610static const struct bin_attribute fsi_slave_raw_attr = {
611 .attr = {
612 .name = "raw",
613 .mode = 0600,
614 },
615 .size = 0,
616 .read = fsi_slave_sysfs_raw_read,
617 .write = fsi_slave_sysfs_raw_write,
618};
619
620static void fsi_slave_release(struct device *dev)
621{
622 struct fsi_slave *slave = to_fsi_slave(dev);
623
624 fsi_free_minor(dev: slave->dev.devt);
625 of_node_put(node: dev->of_node);
626 kfree(objp: slave);
627}
628
629static bool fsi_slave_node_matches(struct device_node *np,
630 int link, uint8_t id)
631{
632 u64 addr;
633
634 if (of_property_read_reg(np, idx: 0, addr: &addr, NULL))
635 return false;
636
637 return addr == (((u64)link << 32) | id);
638}
639
640/* Find a matching node for the slave at (link, id). Returns NULL if none
641 * found, or a matching node with refcount already incremented.
642 */
643static struct device_node *fsi_slave_find_of_node(struct fsi_master *master,
644 int link, uint8_t id)
645{
646 struct device_node *parent, *np;
647
648 parent = dev_of_node(dev: &master->dev);
649 if (!parent)
650 return NULL;
651
652 for_each_child_of_node(parent, np) {
653 if (fsi_slave_node_matches(np, link, id))
654 return np;
655 }
656
657 return NULL;
658}
659
660static ssize_t cfam_read(struct file *filep, char __user *buf, size_t count,
661 loff_t *offset)
662{
663 struct fsi_slave *slave = filep->private_data;
664 size_t total_len, read_len;
665 loff_t off = *offset;
666 ssize_t rc;
667
668 if (off < 0)
669 return -EINVAL;
670
671 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
672 return -EINVAL;
673
674 for (total_len = 0; total_len < count; total_len += read_len) {
675 __be32 data;
676
677 read_len = min_t(size_t, count, 4);
678 read_len -= off & 0x3;
679
680 rc = fsi_slave_read(slave, off, &data, read_len);
681 if (rc)
682 goto fail;
683 rc = copy_to_user(to: buf + total_len, from: &data, n: read_len);
684 if (rc) {
685 rc = -EFAULT;
686 goto fail;
687 }
688 off += read_len;
689 }
690 rc = count;
691 fail:
692 *offset = off;
693 return rc;
694}
695
696static ssize_t cfam_write(struct file *filep, const char __user *buf,
697 size_t count, loff_t *offset)
698{
699 struct fsi_slave *slave = filep->private_data;
700 size_t total_len, write_len;
701 loff_t off = *offset;
702 ssize_t rc;
703
704
705 if (off < 0)
706 return -EINVAL;
707
708 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
709 return -EINVAL;
710
711 for (total_len = 0; total_len < count; total_len += write_len) {
712 __be32 data;
713
714 write_len = min_t(size_t, count, 4);
715 write_len -= off & 0x3;
716
717 rc = copy_from_user(to: &data, from: buf + total_len, n: write_len);
718 if (rc) {
719 rc = -EFAULT;
720 goto fail;
721 }
722 rc = fsi_slave_write(slave, off, &data, write_len);
723 if (rc)
724 goto fail;
725 off += write_len;
726 }
727 rc = count;
728 fail:
729 *offset = off;
730 return rc;
731}
732
733static loff_t cfam_llseek(struct file *file, loff_t offset, int whence)
734{
735 switch (whence) {
736 case SEEK_CUR:
737 break;
738 case SEEK_SET:
739 file->f_pos = offset;
740 break;
741 default:
742 return -EINVAL;
743 }
744
745 return offset;
746}
747
748static int cfam_open(struct inode *inode, struct file *file)
749{
750 struct fsi_slave *slave = container_of(inode->i_cdev, struct fsi_slave, cdev);
751
752 file->private_data = slave;
753
754 return 0;
755}
756
757static const struct file_operations cfam_fops = {
758 .owner = THIS_MODULE,
759 .open = cfam_open,
760 .llseek = cfam_llseek,
761 .read = cfam_read,
762 .write = cfam_write,
763};
764
765static ssize_t send_term_store(struct device *dev,
766 struct device_attribute *attr,
767 const char *buf, size_t count)
768{
769 struct fsi_slave *slave = to_fsi_slave(dev);
770 struct fsi_master *master = slave->master;
771
772 if (!master->term)
773 return -ENODEV;
774
775 master->term(master, slave->link, slave->id);
776 return count;
777}
778
779static DEVICE_ATTR_WO(send_term);
780
781static ssize_t slave_send_echo_show(struct device *dev,
782 struct device_attribute *attr,
783 char *buf)
784{
785 struct fsi_slave *slave = to_fsi_slave(dev);
786
787 return sprintf(buf, fmt: "%u\n", slave->t_send_delay);
788}
789
790static ssize_t slave_send_echo_store(struct device *dev,
791 struct device_attribute *attr, const char *buf, size_t count)
792{
793 struct fsi_slave *slave = to_fsi_slave(dev);
794 struct fsi_master *master = slave->master;
795 unsigned long val;
796 int rc;
797
798 if (kstrtoul(s: buf, base: 0, res: &val) < 0)
799 return -EINVAL;
800
801 if (val < 1 || val > 16)
802 return -EINVAL;
803
804 if (!master->link_config)
805 return -ENXIO;
806
807 /* Current HW mandates that send and echo delay are identical */
808 slave->t_send_delay = val;
809 slave->t_echo_delay = val;
810
811 rc = fsi_slave_set_smode(slave);
812 if (rc < 0)
813 return rc;
814 if (master->link_config)
815 master->link_config(master, slave->link,
816 slave->t_send_delay,
817 slave->t_echo_delay);
818
819 return count;
820}
821
822static DEVICE_ATTR(send_echo_delays, 0600,
823 slave_send_echo_show, slave_send_echo_store);
824
825static ssize_t chip_id_show(struct device *dev,
826 struct device_attribute *attr,
827 char *buf)
828{
829 struct fsi_slave *slave = to_fsi_slave(dev);
830
831 return sprintf(buf, fmt: "%d\n", slave->chip_id);
832}
833
834static DEVICE_ATTR_RO(chip_id);
835
836static ssize_t cfam_id_show(struct device *dev,
837 struct device_attribute *attr,
838 char *buf)
839{
840 struct fsi_slave *slave = to_fsi_slave(dev);
841
842 return sprintf(buf, fmt: "0x%x\n", slave->cfam_id);
843}
844
845static DEVICE_ATTR_RO(cfam_id);
846
847static struct attribute *cfam_attr[] = {
848 &dev_attr_send_echo_delays.attr,
849 &dev_attr_chip_id.attr,
850 &dev_attr_cfam_id.attr,
851 &dev_attr_send_term.attr,
852 NULL,
853};
854
855static const struct attribute_group cfam_attr_group = {
856 .attrs = cfam_attr,
857};
858
859static const struct attribute_group *cfam_attr_groups[] = {
860 &cfam_attr_group,
861 NULL,
862};
863
864static char *cfam_devnode(const struct device *dev, umode_t *mode,
865 kuid_t *uid, kgid_t *gid)
866{
867 const struct fsi_slave *slave = to_fsi_slave(dev);
868
869#ifdef CONFIG_FSI_NEW_DEV_NODE
870 return kasprintf(GFP_KERNEL, fmt: "fsi/cfam%d", slave->cdev_idx);
871#else
872 return kasprintf(GFP_KERNEL, "cfam%d", slave->cdev_idx);
873#endif
874}
875
876static const struct device_type cfam_type = {
877 .name = "cfam",
878 .devnode = cfam_devnode,
879 .groups = cfam_attr_groups
880};
881
882static char *fsi_cdev_devnode(const struct device *dev, umode_t *mode,
883 kuid_t *uid, kgid_t *gid)
884{
885#ifdef CONFIG_FSI_NEW_DEV_NODE
886 return kasprintf(GFP_KERNEL, fmt: "fsi/%s", dev_name(dev));
887#else
888 return kasprintf(GFP_KERNEL, "%s", dev_name(dev));
889#endif
890}
891
892const struct device_type fsi_cdev_type = {
893 .name = "fsi-cdev",
894 .devnode = fsi_cdev_devnode,
895};
896EXPORT_SYMBOL_GPL(fsi_cdev_type);
897
898/* Backward compatible /dev/ numbering in "old style" mode */
899static int fsi_adjust_index(int index)
900{
901#ifdef CONFIG_FSI_NEW_DEV_NODE
902 return index;
903#else
904 return index + 1;
905#endif
906}
907
908static int __fsi_get_new_minor(struct fsi_slave *slave, enum fsi_dev_type type,
909 dev_t *out_dev, int *out_index)
910{
911 int cid = slave->chip_id;
912 int id;
913
914 /* Check if we qualify for legacy numbering */
915 if (cid >= 0 && cid < 16 && type < 4) {
916 /*
917 * Try reserving the legacy number, which has 0 - 0x3f reserved
918 * in the ida range. cid goes up to 0xf and type contains two
919 * bits, so construct the id with the below two bit shift.
920 */
921 id = (cid << 2) | type;
922 id = ida_alloc_range(&fsi_minor_ida, min: id, max: id, GFP_KERNEL);
923 if (id >= 0) {
924 *out_index = fsi_adjust_index(index: cid);
925 *out_dev = fsi_base_dev + id;
926 return 0;
927 }
928 /* Other failure */
929 if (id != -ENOSPC)
930 return id;
931 /* Fallback to non-legacy allocation */
932 }
933 id = ida_alloc_range(&fsi_minor_ida, FSI_CHAR_LEGACY_TOP,
934 FSI_CHAR_MAX_DEVICES - 1, GFP_KERNEL);
935 if (id < 0)
936 return id;
937 *out_index = fsi_adjust_index(index: id);
938 *out_dev = fsi_base_dev + id;
939 return 0;
940}
941
942static const char *const fsi_dev_type_names[] = {
943 "cfam",
944 "sbefifo",
945 "scom",
946 "occ",
947};
948
949int fsi_get_new_minor(struct fsi_device *fdev, enum fsi_dev_type type,
950 dev_t *out_dev, int *out_index)
951{
952 if (fdev->dev.of_node) {
953 int aid = of_alias_get_id(np: fdev->dev.of_node, stem: fsi_dev_type_names[type]);
954
955 if (aid >= 0) {
956 /* Use the same scheme as the legacy numbers. */
957 int id = (aid << 2) | type;
958
959 id = ida_alloc_range(&fsi_minor_ida, min: id, max: id, GFP_KERNEL);
960 if (id >= 0) {
961 *out_index = aid;
962 *out_dev = fsi_base_dev + id;
963 return 0;
964 }
965
966 if (id != -ENOSPC)
967 return id;
968 }
969 }
970
971 return __fsi_get_new_minor(slave: fdev->slave, type, out_dev, out_index);
972}
973EXPORT_SYMBOL_GPL(fsi_get_new_minor);
974
975void fsi_free_minor(dev_t dev)
976{
977 ida_free(&fsi_minor_ida, MINOR(dev));
978}
979EXPORT_SYMBOL_GPL(fsi_free_minor);
980
981static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
982{
983 uint32_t cfam_id;
984 struct fsi_slave *slave;
985 uint8_t crc;
986 __be32 data, llmode, slbus;
987 int rc;
988
989 /* Currently, we only support single slaves on a link, and use the
990 * full 23-bit address range
991 */
992 if (id != 0)
993 return -EINVAL;
994
995 rc = fsi_master_read(master, link, slave_id: id, addr: 0, val: &data, size: sizeof(data));
996 if (rc) {
997 dev_dbg(&master->dev, "can't read slave %02x:%02x %d\n",
998 link, id, rc);
999 return -ENODEV;
1000 }
1001 cfam_id = be32_to_cpu(data);
1002
1003 crc = crc4(c: 0, x: cfam_id, bits: 32);
1004 if (crc) {
1005 trace_fsi_slave_invalid_cfam(master, link, cfam_id);
1006 dev_warn(&master->dev, "slave %02x:%02x invalid cfam id CRC!\n",
1007 link, id);
1008 return -EIO;
1009 }
1010
1011 dev_dbg(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n",
1012 cfam_id, master->idx, link, id);
1013
1014 /* If we're behind a master that doesn't provide a self-running bus
1015 * clock, put the slave into async mode
1016 */
1017 if (master->flags & FSI_MASTER_FLAG_SWCLOCK) {
1018 llmode = cpu_to_be32(FSI_LLMODE_ASYNC);
1019 rc = fsi_master_write(master, link, slave_id: id,
1020 FSI_SLAVE_BASE + FSI_LLMODE,
1021 val: &llmode, size: sizeof(llmode));
1022 if (rc)
1023 dev_warn(&master->dev,
1024 "can't set llmode on slave:%02x:%02x %d\n",
1025 link, id, rc);
1026 }
1027
1028 /* We can communicate with a slave; create the slave device and
1029 * register.
1030 */
1031 slave = kzalloc(sizeof(*slave), GFP_KERNEL);
1032 if (!slave)
1033 return -ENOMEM;
1034
1035 dev_set_name(dev: &slave->dev, name: "slave@%02x:%02x", link, id);
1036 slave->dev.type = &cfam_type;
1037 slave->dev.parent = &master->dev;
1038 slave->dev.of_node = fsi_slave_find_of_node(master, link, id);
1039 slave->dev.release = fsi_slave_release;
1040 device_initialize(dev: &slave->dev);
1041 slave->cfam_id = cfam_id;
1042 slave->master = master;
1043 slave->link = link;
1044 slave->id = id;
1045 slave->size = FSI_SLAVE_SIZE_23b;
1046 slave->t_send_delay = 16;
1047 slave->t_echo_delay = 16;
1048
1049 /* Get chip ID if any */
1050 slave->chip_id = -1;
1051 if (slave->dev.of_node) {
1052 uint32_t prop;
1053 if (!of_property_read_u32(np: slave->dev.of_node, propname: "chip-id", out_value: &prop))
1054 slave->chip_id = prop;
1055
1056 }
1057
1058 slbus = cpu_to_be32(FSI_SLBUS_FORCE);
1059 rc = fsi_master_write(master, link, slave_id: id, FSI_SLAVE_BASE + FSI_SLBUS,
1060 val: &slbus, size: sizeof(slbus));
1061 if (rc)
1062 dev_warn(&master->dev,
1063 "can't set slbus on slave:%02x:%02x %d\n", link, id,
1064 rc);
1065
1066 rc = fsi_slave_set_smode(slave);
1067 if (rc) {
1068 dev_warn(&master->dev,
1069 "can't set smode on slave:%02x:%02x %d\n",
1070 link, id, rc);
1071 goto err_free;
1072 }
1073
1074 /* Allocate a minor in the FSI space */
1075 rc = __fsi_get_new_minor(slave, type: fsi_dev_cfam, out_dev: &slave->dev.devt,
1076 out_index: &slave->cdev_idx);
1077 if (rc)
1078 goto err_free;
1079
1080 trace_fsi_slave_init(slave);
1081
1082 /* Create chardev for userspace access */
1083 cdev_init(&slave->cdev, &cfam_fops);
1084 rc = cdev_device_add(cdev: &slave->cdev, dev: &slave->dev);
1085 if (rc) {
1086 dev_err(&slave->dev, "Error %d creating slave device\n", rc);
1087 goto err_free_ida;
1088 }
1089
1090 /* Now that we have the cdev registered with the core, any fatal
1091 * failures beyond this point will need to clean up through
1092 * cdev_device_del(). Fortunately though, nothing past here is fatal.
1093 */
1094
1095 if (master->link_config)
1096 master->link_config(master, link,
1097 slave->t_send_delay,
1098 slave->t_echo_delay);
1099
1100 /* Legacy raw file -> to be removed */
1101 rc = device_create_bin_file(dev: &slave->dev, attr: &fsi_slave_raw_attr);
1102 if (rc)
1103 dev_warn(&slave->dev, "failed to create raw attr: %d\n", rc);
1104
1105
1106 rc = fsi_slave_scan(slave);
1107 if (rc)
1108 dev_dbg(&master->dev, "failed during slave scan with: %d\n",
1109 rc);
1110
1111 return 0;
1112
1113err_free_ida:
1114 fsi_free_minor(slave->dev.devt);
1115err_free:
1116 of_node_put(node: slave->dev.of_node);
1117 kfree(objp: slave);
1118 return rc;
1119}
1120
1121/* FSI master support */
1122static int fsi_check_access(uint32_t addr, size_t size)
1123{
1124 if (size == 4) {
1125 if (addr & 0x3)
1126 return -EINVAL;
1127 } else if (size == 2) {
1128 if (addr & 0x1)
1129 return -EINVAL;
1130 } else if (size != 1)
1131 return -EINVAL;
1132
1133 return 0;
1134}
1135
1136static int fsi_master_read(struct fsi_master *master, int link,
1137 uint8_t slave_id, uint32_t addr, void *val, size_t size)
1138{
1139 int rc;
1140
1141 trace_fsi_master_read(master, link, id: slave_id, addr, size);
1142
1143 rc = fsi_check_access(addr, size);
1144 if (!rc)
1145 rc = master->read(master, link, slave_id, addr, val, size);
1146
1147 trace_fsi_master_rw_result(master, link, id: slave_id, addr, size,
1148 write: false, data: val, ret: rc);
1149
1150 return rc;
1151}
1152
1153static int fsi_master_write(struct fsi_master *master, int link,
1154 uint8_t slave_id, uint32_t addr, const void *val, size_t size)
1155{
1156 int rc;
1157
1158 trace_fsi_master_write(master, link, id: slave_id, addr, size, data: val);
1159
1160 rc = fsi_check_access(addr, size);
1161 if (!rc)
1162 rc = master->write(master, link, slave_id, addr, val, size);
1163
1164 trace_fsi_master_rw_result(master, link, id: slave_id, addr, size,
1165 write: true, data: val, ret: rc);
1166
1167 return rc;
1168}
1169
1170static int fsi_master_link_disable(struct fsi_master *master, int link)
1171{
1172 if (master->link_enable)
1173 return master->link_enable(master, link, false);
1174
1175 return 0;
1176}
1177
1178static int fsi_master_link_enable(struct fsi_master *master, int link)
1179{
1180 if (master->link_enable)
1181 return master->link_enable(master, link, true);
1182
1183 return 0;
1184}
1185
1186/*
1187 * Issue a break command on this link
1188 */
1189static int fsi_master_break(struct fsi_master *master, int link)
1190{
1191 int rc = 0;
1192
1193 trace_fsi_master_break(master, link);
1194
1195 if (master->send_break)
1196 rc = master->send_break(master, link);
1197 if (master->link_config)
1198 master->link_config(master, link, 16, 16);
1199
1200 return rc;
1201}
1202
1203static int fsi_master_scan(struct fsi_master *master)
1204{
1205 int link, rc;
1206
1207 trace_fsi_master_scan(master, scan: true);
1208 for (link = 0; link < master->n_links; link++) {
1209 rc = fsi_master_link_enable(master, link);
1210 if (rc) {
1211 dev_dbg(&master->dev,
1212 "enable link %d failed: %d\n", link, rc);
1213 continue;
1214 }
1215 rc = fsi_master_break(master, link);
1216 if (rc) {
1217 fsi_master_link_disable(master, link);
1218 dev_dbg(&master->dev,
1219 "break to link %d failed: %d\n", link, rc);
1220 continue;
1221 }
1222
1223 rc = fsi_slave_init(master, link, id: 0);
1224 if (rc)
1225 fsi_master_link_disable(master, link);
1226 }
1227
1228 return 0;
1229}
1230
1231static int fsi_slave_remove_device(struct device *dev, void *arg)
1232{
1233 device_unregister(dev);
1234 return 0;
1235}
1236
1237static int fsi_master_remove_slave(struct device *dev, void *arg)
1238{
1239 struct fsi_slave *slave = to_fsi_slave(dev);
1240
1241 device_for_each_child(parent: dev, NULL, fn: fsi_slave_remove_device);
1242 cdev_device_del(cdev: &slave->cdev, dev: &slave->dev);
1243 put_device(dev);
1244 return 0;
1245}
1246
1247static void fsi_master_unscan(struct fsi_master *master)
1248{
1249 trace_fsi_master_scan(master, scan: false);
1250 device_for_each_child(parent: &master->dev, NULL, fn: fsi_master_remove_slave);
1251}
1252
1253int fsi_master_rescan(struct fsi_master *master)
1254{
1255 int rc;
1256
1257 mutex_lock(&master->scan_lock);
1258 fsi_master_unscan(master);
1259 rc = fsi_master_scan(master);
1260 mutex_unlock(lock: &master->scan_lock);
1261
1262 return rc;
1263}
1264EXPORT_SYMBOL_GPL(fsi_master_rescan);
1265
1266static ssize_t master_rescan_store(struct device *dev,
1267 struct device_attribute *attr, const char *buf, size_t count)
1268{
1269 struct fsi_master *master = to_fsi_master(dev);
1270 int rc;
1271
1272 rc = fsi_master_rescan(master);
1273 if (rc < 0)
1274 return rc;
1275
1276 return count;
1277}
1278
1279static DEVICE_ATTR(rescan, 0200, NULL, master_rescan_store);
1280
1281static ssize_t master_break_store(struct device *dev,
1282 struct device_attribute *attr, const char *buf, size_t count)
1283{
1284 struct fsi_master *master = to_fsi_master(dev);
1285
1286 fsi_master_break(master, link: 0);
1287
1288 return count;
1289}
1290
1291static DEVICE_ATTR(break, 0200, NULL, master_break_store);
1292
1293static struct attribute *master_attrs[] = {
1294 &dev_attr_break.attr,
1295 &dev_attr_rescan.attr,
1296 NULL
1297};
1298
1299ATTRIBUTE_GROUPS(master);
1300
1301static struct class fsi_master_class = {
1302 .name = "fsi-master",
1303 .dev_groups = master_groups,
1304};
1305
1306int fsi_master_register(struct fsi_master *master)
1307{
1308 int rc;
1309 struct device_node *np;
1310
1311 mutex_init(&master->scan_lock);
1312
1313 /* Alloc the requested index if it's non-zero */
1314 if (master->idx) {
1315 master->idx = ida_alloc_range(&master_ida, min: master->idx,
1316 max: master->idx, GFP_KERNEL);
1317 } else {
1318 master->idx = ida_alloc(ida: &master_ida, GFP_KERNEL);
1319 }
1320
1321 if (master->idx < 0)
1322 return master->idx;
1323
1324 if (!dev_name(dev: &master->dev))
1325 dev_set_name(dev: &master->dev, name: "fsi%d", master->idx);
1326
1327 master->dev.class = &fsi_master_class;
1328
1329 mutex_lock(&master->scan_lock);
1330 rc = device_register(dev: &master->dev);
1331 if (rc) {
1332 ida_free(&master_ida, id: master->idx);
1333 goto out;
1334 }
1335
1336 np = dev_of_node(dev: &master->dev);
1337 if (!of_property_read_bool(np, propname: "no-scan-on-init")) {
1338 fsi_master_scan(master);
1339 }
1340out:
1341 mutex_unlock(lock: &master->scan_lock);
1342 return rc;
1343}
1344EXPORT_SYMBOL_GPL(fsi_master_register);
1345
1346void fsi_master_unregister(struct fsi_master *master)
1347{
1348 int idx = master->idx;
1349
1350 trace_fsi_master_unregister(master);
1351
1352 mutex_lock(&master->scan_lock);
1353 fsi_master_unscan(master);
1354 master->n_links = 0;
1355 mutex_unlock(lock: &master->scan_lock);
1356
1357 device_unregister(dev: &master->dev);
1358 ida_free(&master_ida, id: idx);
1359}
1360EXPORT_SYMBOL_GPL(fsi_master_unregister);
1361
1362/* FSI core & Linux bus type definitions */
1363
1364static int fsi_bus_match(struct device *dev, const struct device_driver *drv)
1365{
1366 struct fsi_device *fsi_dev = to_fsi_dev(dev);
1367 const struct fsi_driver *fsi_drv = to_fsi_drv(drv);
1368 const struct fsi_device_id *id;
1369
1370 if (!fsi_drv->id_table)
1371 return 0;
1372
1373 for (id = fsi_drv->id_table; id->engine_type; id++) {
1374 if (id->engine_type != fsi_dev->engine_type)
1375 continue;
1376 if (id->version == FSI_VERSION_ANY ||
1377 id->version == fsi_dev->version) {
1378 if (drv->of_match_table) {
1379 if (of_driver_match_device(dev, drv))
1380 return 1;
1381 } else {
1382 return 1;
1383 }
1384 }
1385 }
1386
1387 return 0;
1388}
1389
1390int fsi_driver_register(struct fsi_driver *fsi_drv)
1391{
1392 if (!fsi_drv)
1393 return -EINVAL;
1394 if (!fsi_drv->id_table)
1395 return -EINVAL;
1396
1397 return driver_register(drv: &fsi_drv->drv);
1398}
1399EXPORT_SYMBOL_GPL(fsi_driver_register);
1400
1401void fsi_driver_unregister(struct fsi_driver *fsi_drv)
1402{
1403 driver_unregister(drv: &fsi_drv->drv);
1404}
1405EXPORT_SYMBOL_GPL(fsi_driver_unregister);
1406
1407const struct bus_type fsi_bus_type = {
1408 .name = "fsi",
1409 .match = fsi_bus_match,
1410};
1411EXPORT_SYMBOL_GPL(fsi_bus_type);
1412
1413static int __init fsi_init(void)
1414{
1415 int rc;
1416
1417 rc = alloc_chrdev_region(&fsi_base_dev, 0, FSI_CHAR_MAX_DEVICES, "fsi");
1418 if (rc)
1419 return rc;
1420 rc = bus_register(bus: &fsi_bus_type);
1421 if (rc)
1422 goto fail_bus;
1423
1424 rc = class_register(class: &fsi_master_class);
1425 if (rc)
1426 goto fail_class;
1427
1428 return 0;
1429
1430 fail_class:
1431 bus_unregister(bus: &fsi_bus_type);
1432 fail_bus:
1433 unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES);
1434 return rc;
1435}
1436postcore_initcall(fsi_init);
1437
1438static void fsi_exit(void)
1439{
1440 class_unregister(class: &fsi_master_class);
1441 bus_unregister(bus: &fsi_bus_type);
1442 unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES);
1443 ida_destroy(ida: &fsi_minor_ida);
1444}
1445module_exit(fsi_exit);
1446module_param(discard_errors, int, 0664);
1447MODULE_DESCRIPTION("FSI core driver");
1448MODULE_LICENSE("GPL");
1449MODULE_PARM_DESC(discard_errors, "Don't invoke error handling on bus accesses");
1450

source code of linux/drivers/fsi/fsi-core.c