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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 FSI_SLAVE_CONF_NEXT_MASK GENMASK(31, 31)
28#define FSI_SLAVE_CONF_SLOTS_MASK GENMASK(23, 16)
29#define FSI_SLAVE_CONF_SLOTS_SHIFT 16
30#define FSI_SLAVE_CONF_VERSION_MASK GENMASK(15, 12)
31#define FSI_SLAVE_CONF_VERSION_SHIFT 12
32#define FSI_SLAVE_CONF_TYPE_MASK GENMASK(11, 4)
33#define FSI_SLAVE_CONF_TYPE_SHIFT 4
34#define FSI_SLAVE_CONF_CRC_SHIFT 4
35#define FSI_SLAVE_CONF_CRC_MASK GENMASK(3, 0)
36#define FSI_SLAVE_CONF_DATA_BITS 28
37
38#define FSI_PEEK_BASE 0x410
39
40static const int engine_page_size = 0x400;
41
42#define FSI_SLAVE_BASE 0x800
43
44/*
45 * FSI slave engine control register offsets
46 */
47#define FSI_SMODE 0x0 /* R/W: Mode register */
48#define FSI_SISC 0x8 /* R/W: Interrupt condition */
49#define FSI_SSTAT 0x14 /* R : Slave status */
50#define FSI_SLBUS 0x30 /* W : LBUS Ownership */
51#define FSI_LLMODE 0x100 /* R/W: Link layer mode register */
52
53/*
54 * SMODE fields
55 */
56#define FSI_SMODE_WSC 0x80000000 /* Warm start done */
57#define FSI_SMODE_ECRC 0x20000000 /* Hw CRC check */
58#define FSI_SMODE_SID_SHIFT 24 /* ID shift */
59#define FSI_SMODE_SID_MASK 3 /* ID Mask */
60#define FSI_SMODE_ED_SHIFT 20 /* Echo delay shift */
61#define FSI_SMODE_ED_MASK 0xf /* Echo delay mask */
62#define FSI_SMODE_SD_SHIFT 16 /* Send delay shift */
63#define FSI_SMODE_SD_MASK 0xf /* Send delay mask */
64#define FSI_SMODE_LBCRR_SHIFT 8 /* Clk ratio shift */
65#define FSI_SMODE_LBCRR_MASK 0xf /* Clk ratio mask */
66
67/*
68 * SLBUS fields
69 */
70#define FSI_SLBUS_FORCE 0x80000000 /* Force LBUS ownership */
71
72/*
73 * LLMODE fields
74 */
75#define FSI_LLMODE_ASYNC 0x1
76
77#define FSI_SLAVE_SIZE_23b 0x800000
78
79static DEFINE_IDA(master_ida);
80
81struct fsi_slave {
82 struct device dev;
83 struct fsi_master *master;
84 struct cdev cdev;
85 int cdev_idx;
86 int id; /* FSI address */
87 int link; /* FSI link# */
88 u32 cfam_id;
89 int chip_id;
90 uint32_t size; /* size of slave address space */
91 u8 t_send_delay;
92 u8 t_echo_delay;
93};
94
95#define CREATE_TRACE_POINTS
96#include <trace/events/fsi.h>
97
98#define to_fsi_master(d) container_of(d, struct fsi_master, dev)
99#define to_fsi_slave(d) container_of(d, struct fsi_slave, dev)
100
101static const int slave_retries = 2;
102static int discard_errors;
103
104static dev_t fsi_base_dev;
105static DEFINE_IDA(fsi_minor_ida);
106#define FSI_CHAR_MAX_DEVICES 0x1000
107
108/* Legacy /dev numbering: 4 devices per chip, 16 chips */
109#define FSI_CHAR_LEGACY_TOP 64
110
111static int fsi_master_read(struct fsi_master *master, int link,
112 uint8_t slave_id, uint32_t addr, void *val, size_t size);
113static int fsi_master_write(struct fsi_master *master, int link,
114 uint8_t slave_id, uint32_t addr, const void *val, size_t size);
115static int fsi_master_break(struct fsi_master *master, int link);
116
117/*
118 * fsi_device_read() / fsi_device_write() / fsi_device_peek()
119 *
120 * FSI endpoint-device support
121 *
122 * Read / write / peek accessors for a client
123 *
124 * Parameters:
125 * dev: Structure passed to FSI client device drivers on probe().
126 * addr: FSI address of given device. Client should pass in its base address
127 * plus desired offset to access its register space.
128 * val: For read/peek this is the value read at the specified address. For
129 * write this is value to write to the specified address.
130 * The data in val must be FSI bus endian (big endian).
131 * size: Size in bytes of the operation. Sizes supported are 1, 2 and 4 bytes.
132 * Addresses must be aligned on size boundaries or an error will result.
133 */
134int fsi_device_read(struct fsi_device *dev, uint32_t addr, void *val,
135 size_t size)
136{
137 if (addr > dev->size || size > dev->size || addr > dev->size - size)
138 return -EINVAL;
139
140 return fsi_slave_read(dev->slave, dev->addr + addr, val, size);
141}
142EXPORT_SYMBOL_GPL(fsi_device_read);
143
144int fsi_device_write(struct fsi_device *dev, uint32_t addr, const void *val,
145 size_t size)
146{
147 if (addr > dev->size || size > dev->size || addr > dev->size - size)
148 return -EINVAL;
149
150 return fsi_slave_write(dev->slave, dev->addr + addr, val, size);
151}
152EXPORT_SYMBOL_GPL(fsi_device_write);
153
154int fsi_device_peek(struct fsi_device *dev, void *val)
155{
156 uint32_t addr = FSI_PEEK_BASE + ((dev->unit - 2) * sizeof(uint32_t));
157
158 return fsi_slave_read(dev->slave, addr, val, sizeof(uint32_t));
159}
160
161static void fsi_device_release(struct device *_device)
162{
163 struct fsi_device *device = to_fsi_dev(_device);
164
165 of_node_put(device->dev.of_node);
166 kfree(device);
167}
168
169static struct fsi_device *fsi_create_device(struct fsi_slave *slave)
170{
171 struct fsi_device *dev;
172
173 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
174 if (!dev)
175 return NULL;
176
177 dev->dev.parent = &slave->dev;
178 dev->dev.bus = &fsi_bus_type;
179 dev->dev.release = fsi_device_release;
180
181 return dev;
182}
183
184/* FSI slave support */
185static int fsi_slave_calc_addr(struct fsi_slave *slave, uint32_t *addrp,
186 uint8_t *idp)
187{
188 uint32_t addr = *addrp;
189 uint8_t id = *idp;
190
191 if (addr > slave->size)
192 return -EINVAL;
193
194 /* For 23 bit addressing, we encode the extra two bits in the slave
195 * id (and the slave's actual ID needs to be 0).
196 */
197 if (addr > 0x1fffff) {
198 if (slave->id != 0)
199 return -EINVAL;
200 id = (addr >> 21) & 0x3;
201 addr &= 0x1fffff;
202 }
203
204 *addrp = addr;
205 *idp = id;
206 return 0;
207}
208
209static int fsi_slave_report_and_clear_errors(struct fsi_slave *slave)
210{
211 struct fsi_master *master = slave->master;
212 __be32 irq, stat;
213 int rc, link;
214 uint8_t id;
215
216 link = slave->link;
217 id = slave->id;
218
219 rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SISC,
220 &irq, sizeof(irq));
221 if (rc)
222 return rc;
223
224 rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SSTAT,
225 &stat, sizeof(stat));
226 if (rc)
227 return rc;
228
229 dev_dbg(&slave->dev, "status: 0x%08x, sisc: 0x%08x\n",
230 be32_to_cpu(stat), be32_to_cpu(irq));
231
232 /* clear interrupts */
233 return fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SISC,
234 &irq, sizeof(irq));
235}
236
237/* Encode slave local bus echo delay */
238static inline uint32_t fsi_smode_echodly(int x)
239{
240 return (x & FSI_SMODE_ED_MASK) << FSI_SMODE_ED_SHIFT;
241}
242
243/* Encode slave local bus send delay */
244static inline uint32_t fsi_smode_senddly(int x)
245{
246 return (x & FSI_SMODE_SD_MASK) << FSI_SMODE_SD_SHIFT;
247}
248
249/* Encode slave local bus clock rate ratio */
250static inline uint32_t fsi_smode_lbcrr(int x)
251{
252 return (x & FSI_SMODE_LBCRR_MASK) << FSI_SMODE_LBCRR_SHIFT;
253}
254
255/* Encode slave ID */
256static inline uint32_t fsi_smode_sid(int x)
257{
258 return (x & FSI_SMODE_SID_MASK) << FSI_SMODE_SID_SHIFT;
259}
260
261static uint32_t fsi_slave_smode(int id, u8 t_senddly, u8 t_echodly)
262{
263 return FSI_SMODE_WSC | FSI_SMODE_ECRC
264 | fsi_smode_sid(id)
265 | fsi_smode_echodly(t_echodly - 1) | fsi_smode_senddly(t_senddly - 1)
266 | fsi_smode_lbcrr(0x8);
267}
268
269static int fsi_slave_set_smode(struct fsi_slave *slave)
270{
271 uint32_t smode;
272 __be32 data;
273
274 /* set our smode register with the slave ID field to 0; this enables
275 * extended slave addressing
276 */
277 smode = fsi_slave_smode(slave->id, slave->t_send_delay, slave->t_echo_delay);
278 data = cpu_to_be32(smode);
279
280 return fsi_master_write(slave->master, slave->link, slave->id,
281 FSI_SLAVE_BASE + FSI_SMODE,
282 &data, sizeof(data));
283}
284
285static int fsi_slave_handle_error(struct fsi_slave *slave, bool write,
286 uint32_t addr, size_t size)
287{
288 struct fsi_master *master = slave->master;
289 int rc, link;
290 uint32_t reg;
291 uint8_t id, send_delay, echo_delay;
292
293 if (discard_errors)
294 return -1;
295
296 link = slave->link;
297 id = slave->id;
298
299 dev_dbg(&slave->dev, "handling error on %s to 0x%08x[%zd]",
300 write ? "write" : "read", addr, size);
301
302 /* try a simple clear of error conditions, which may fail if we've lost
303 * communication with the slave
304 */
305 rc = fsi_slave_report_and_clear_errors(slave);
306 if (!rc)
307 return 0;
308
309 /* send a TERM and retry */
310 if (master->term) {
311 rc = master->term(master, link, id);
312 if (!rc) {
313 rc = fsi_master_read(master, link, id, 0,
314 ®, sizeof(reg));
315 if (!rc)
316 rc = fsi_slave_report_and_clear_errors(slave);
317 if (!rc)
318 return 0;
319 }
320 }
321
322 send_delay = slave->t_send_delay;
323 echo_delay = slave->t_echo_delay;
324
325 /* getting serious, reset the slave via BREAK */
326 rc = fsi_master_break(master, link);
327 if (rc)
328 return rc;
329
330 slave->t_send_delay = send_delay;
331 slave->t_echo_delay = echo_delay;
332
333 rc = fsi_slave_set_smode(slave);
334 if (rc)
335 return rc;
336
337 if (master->link_config)
338 master->link_config(master, link,
339 slave->t_send_delay,
340 slave->t_echo_delay);
341
342 return fsi_slave_report_and_clear_errors(slave);
343}
344
345int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
346 void *val, size_t size)
347{
348 uint8_t id = slave->id;
349 int rc, err_rc, i;
350
351 rc = fsi_slave_calc_addr(slave, &addr, &id);
352 if (rc)
353 return rc;
354
355 for (i = 0; i < slave_retries; i++) {
356 rc = fsi_master_read(slave->master, slave->link,
357 id, addr, val, size);
358 if (!rc)
359 break;
360
361 err_rc = fsi_slave_handle_error(slave, false, addr, size);
362 if (err_rc)
363 break;
364 }
365
366 return rc;
367}
368EXPORT_SYMBOL_GPL(fsi_slave_read);
369
370int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
371 const void *val, size_t size)
372{
373 uint8_t id = slave->id;
374 int rc, err_rc, i;
375
376 rc = fsi_slave_calc_addr(slave, &addr, &id);
377 if (rc)
378 return rc;
379
380 for (i = 0; i < slave_retries; i++) {
381 rc = fsi_master_write(slave->master, slave->link,
382 id, addr, val, size);
383 if (!rc)
384 break;
385
386 err_rc = fsi_slave_handle_error(slave, true, addr, size);
387 if (err_rc)
388 break;
389 }
390
391 return rc;
392}
393EXPORT_SYMBOL_GPL(fsi_slave_write);
394
395int fsi_slave_claim_range(struct fsi_slave *slave,
396 uint32_t addr, uint32_t size)
397{
398 if (addr + size < addr)
399 return -EINVAL;
400
401 if (addr + size > slave->size)
402 return -EINVAL;
403
404 /* todo: check for overlapping claims */
405 return 0;
406}
407EXPORT_SYMBOL_GPL(fsi_slave_claim_range);
408
409void fsi_slave_release_range(struct fsi_slave *slave,
410 uint32_t addr, uint32_t size)
411{
412}
413EXPORT_SYMBOL_GPL(fsi_slave_release_range);
414
415static bool fsi_device_node_matches(struct device *dev, struct device_node *np,
416 uint32_t addr, uint32_t size)
417{
418 unsigned int len, na, ns;
419 const __be32 *prop;
420 uint32_t psize;
421
422 na = of_n_addr_cells(np);
423 ns = of_n_size_cells(np);
424
425 if (na != 1 || ns != 1)
426 return false;
427
428 prop = of_get_property(np, "reg", &len);
429 if (!prop || len != 8)
430 return false;
431
432 if (of_read_number(prop, 1) != addr)
433 return false;
434
435 psize = of_read_number(prop + 1, 1);
436 if (psize != size) {
437 dev_warn(dev,
438 "node %s matches probed address, but not size (got 0x%x, expected 0x%x)",
439 of_node_full_name(np), psize, size);
440 }
441
442 return true;
443}
444
445/* Find a matching node for the slave engine at @address, using @size bytes
446 * of space. Returns NULL if not found, or a matching node with refcount
447 * already incremented.
448 */
449static struct device_node *fsi_device_find_of_node(struct fsi_device *dev)
450{
451 struct device_node *parent, *np;
452
453 parent = dev_of_node(&dev->slave->dev);
454 if (!parent)
455 return NULL;
456
457 for_each_child_of_node(parent, np) {
458 if (fsi_device_node_matches(&dev->dev, np,
459 dev->addr, dev->size))
460 return np;
461 }
462
463 return NULL;
464}
465
466static int fsi_slave_scan(struct fsi_slave *slave)
467{
468 uint32_t engine_addr;
469 int rc, i;
470
471 /*
472 * scan engines
473 *
474 * We keep the peek mode and slave engines for the core; so start
475 * at the third slot in the configuration table. We also need to
476 * skip the chip ID entry at the start of the address space.
477 */
478 engine_addr = engine_page_size * 3;
479 for (i = 2; i < engine_page_size / sizeof(uint32_t); i++) {
480 uint8_t slots, version, type, crc;
481 struct fsi_device *dev;
482 uint32_t conf;
483 __be32 data;
484
485 rc = fsi_slave_read(slave, (i + 1) * sizeof(data),
486 &data, sizeof(data));
487 if (rc) {
488 dev_warn(&slave->dev,
489 "error reading slave registers\n");
490 return -1;
491 }
492 conf = be32_to_cpu(data);
493
494 crc = crc4(0, conf, 32);
495 if (crc) {
496 dev_warn(&slave->dev,
497 "crc error in slave register at 0x%04x\n",
498 i);
499 return -1;
500 }
501
502 slots = (conf & FSI_SLAVE_CONF_SLOTS_MASK)
503 >> FSI_SLAVE_CONF_SLOTS_SHIFT;
504 version = (conf & FSI_SLAVE_CONF_VERSION_MASK)
505 >> FSI_SLAVE_CONF_VERSION_SHIFT;
506 type = (conf & FSI_SLAVE_CONF_TYPE_MASK)
507 >> FSI_SLAVE_CONF_TYPE_SHIFT;
508
509 /*
510 * Unused address areas are marked by a zero type value; this
511 * skips the defined address areas
512 */
513 if (type != 0 && slots != 0) {
514
515 /* create device */
516 dev = fsi_create_device(slave);
517 if (!dev)
518 return -ENOMEM;
519
520 dev->slave = slave;
521 dev->engine_type = type;
522 dev->version = version;
523 dev->unit = i;
524 dev->addr = engine_addr;
525 dev->size = slots * engine_page_size;
526
527 trace_fsi_dev_init(dev);
528
529 dev_dbg(&slave->dev,
530 "engine[%i]: type %x, version %x, addr %x size %x\n",
531 dev->unit, dev->engine_type, version,
532 dev->addr, dev->size);
533
534 dev_set_name(&dev->dev, "%02x:%02x:%02x:%02x",
535 slave->master->idx, slave->link,
536 slave->id, i - 2);
537 dev->dev.of_node = fsi_device_find_of_node(dev);
538
539 rc = device_register(&dev->dev);
540 if (rc) {
541 dev_warn(&slave->dev, "add failed: %d\n", rc);
542 put_device(&dev->dev);
543 }
544 }
545
546 engine_addr += slots * engine_page_size;
547
548 if (!(conf & FSI_SLAVE_CONF_NEXT_MASK))
549 break;
550 }
551
552 return 0;
553}
554
555static unsigned long aligned_access_size(size_t offset, size_t count)
556{
557 unsigned long offset_unit, count_unit;
558
559 /* Criteria:
560 *
561 * 1. Access size must be less than or equal to the maximum access
562 * width or the highest power-of-two factor of offset
563 * 2. Access size must be less than or equal to the amount specified by
564 * count
565 *
566 * The access width is optimal if we can calculate 1 to be strictly
567 * equal while still satisfying 2.
568 */
569
570 /* Find 1 by the bottom bit of offset (with a 4 byte access cap) */
571 offset_unit = BIT(__builtin_ctzl(offset | 4));
572
573 /* Find 2 by the top bit of count */
574 count_unit = BIT(8 * sizeof(unsigned long) - 1 - __builtin_clzl(count));
575
576 /* Constrain the maximum access width to the minimum of both criteria */
577 return BIT(__builtin_ctzl(offset_unit | count_unit));
578}
579
580static ssize_t fsi_slave_sysfs_raw_read(struct file *file,
581 struct kobject *kobj, struct bin_attribute *attr, char *buf,
582 loff_t off, size_t count)
583{
584 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
585 size_t total_len, read_len;
586 int rc;
587
588 if (off < 0)
589 return -EINVAL;
590
591 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
592 return -EINVAL;
593
594 for (total_len = 0; total_len < count; total_len += read_len) {
595 read_len = aligned_access_size(off, count - total_len);
596
597 rc = fsi_slave_read(slave, off, buf + total_len, read_len);
598 if (rc)
599 return rc;
600
601 off += read_len;
602 }
603
604 return count;
605}
606
607static ssize_t fsi_slave_sysfs_raw_write(struct file *file,
608 struct kobject *kobj, struct bin_attribute *attr,
609 char *buf, loff_t off, size_t count)
610{
611 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
612 size_t total_len, write_len;
613 int rc;
614
615 if (off < 0)
616 return -EINVAL;
617
618 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
619 return -EINVAL;
620
621 for (total_len = 0; total_len < count; total_len += write_len) {
622 write_len = aligned_access_size(off, count - total_len);
623
624 rc = fsi_slave_write(slave, off, buf + total_len, write_len);
625 if (rc)
626 return rc;
627
628 off += write_len;
629 }
630
631 return count;
632}
633
634static const struct bin_attribute fsi_slave_raw_attr = {
635 .attr = {
636 .name = "raw",
637 .mode = 0600,
638 },
639 .size = 0,
640 .read = fsi_slave_sysfs_raw_read,
641 .write = fsi_slave_sysfs_raw_write,
642};
643
644static void fsi_slave_release(struct device *dev)
645{
646 struct fsi_slave *slave = to_fsi_slave(dev);
647
648 fsi_free_minor(slave->dev.devt);
649 of_node_put(dev->of_node);
650 kfree(slave);
651}
652
653static bool fsi_slave_node_matches(struct device_node *np,
654 int link, uint8_t id)
655{
656 unsigned int len, na, ns;
657 const __be32 *prop;
658
659 na = of_n_addr_cells(np);
660 ns = of_n_size_cells(np);
661
662 /* Ensure we have the correct format for addresses and sizes in
663 * reg properties
664 */
665 if (na != 2 || ns != 0)
666 return false;
667
668 prop = of_get_property(np, "reg", &len);
669 if (!prop || len != 8)
670 return false;
671
672 return (of_read_number(prop, 1) == link) &&
673 (of_read_number(prop + 1, 1) == id);
674}
675
676/* Find a matching node for the slave at (link, id). Returns NULL if none
677 * found, or a matching node with refcount already incremented.
678 */
679static struct device_node *fsi_slave_find_of_node(struct fsi_master *master,
680 int link, uint8_t id)
681{
682 struct device_node *parent, *np;
683
684 parent = dev_of_node(&master->dev);
685 if (!parent)
686 return NULL;
687
688 for_each_child_of_node(parent, np) {
689 if (fsi_slave_node_matches(np, link, id))
690 return np;
691 }
692
693 return NULL;
694}
695
696static ssize_t cfam_read(struct file *filep, char __user *buf, size_t count,
697 loff_t *offset)
698{
699 struct fsi_slave *slave = filep->private_data;
700 size_t total_len, read_len;
701 loff_t off = *offset;
702 ssize_t rc;
703
704 if (off < 0)
705 return -EINVAL;
706
707 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
708 return -EINVAL;
709
710 for (total_len = 0; total_len < count; total_len += read_len) {
711 __be32 data;
712
713 read_len = min_t(size_t, count, 4);
714 read_len -= off & 0x3;
715
716 rc = fsi_slave_read(slave, off, &data, read_len);
717 if (rc)
718 goto fail;
719 rc = copy_to_user(buf + total_len, &data, read_len);
720 if (rc) {
721 rc = -EFAULT;
722 goto fail;
723 }
724 off += read_len;
725 }
726 rc = count;
727 fail:
728 *offset = off;
729 return rc;
730}
731
732static ssize_t cfam_write(struct file *filep, const char __user *buf,
733 size_t count, loff_t *offset)
734{
735 struct fsi_slave *slave = filep->private_data;
736 size_t total_len, write_len;
737 loff_t off = *offset;
738 ssize_t rc;
739
740
741 if (off < 0)
742 return -EINVAL;
743
744 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
745 return -EINVAL;
746
747 for (total_len = 0; total_len < count; total_len += write_len) {
748 __be32 data;
749
750 write_len = min_t(size_t, count, 4);
751 write_len -= off & 0x3;
752
753 rc = copy_from_user(&data, buf + total_len, write_len);
754 if (rc) {
755 rc = -EFAULT;
756 goto fail;
757 }
758 rc = fsi_slave_write(slave, off, &data, write_len);
759 if (rc)
760 goto fail;
761 off += write_len;
762 }
763 rc = count;
764 fail:
765 *offset = off;
766 return rc;
767}
768
769static loff_t cfam_llseek(struct file *file, loff_t offset, int whence)
770{
771 switch (whence) {
772 case SEEK_CUR:
773 break;
774 case SEEK_SET:
775 file->f_pos = offset;
776 break;
777 default:
778 return -EINVAL;
779 }
780
781 return offset;
782}
783
784static int cfam_open(struct inode *inode, struct file *file)
785{
786 struct fsi_slave *slave = container_of(inode->i_cdev, struct fsi_slave, cdev);
787
788 file->private_data = slave;
789
790 return 0;
791}
792
793static const struct file_operations cfam_fops = {
794 .owner = THIS_MODULE,
795 .open = cfam_open,
796 .llseek = cfam_llseek,
797 .read = cfam_read,
798 .write = cfam_write,
799};
800
801static ssize_t send_term_store(struct device *dev,
802 struct device_attribute *attr,
803 const char *buf, size_t count)
804{
805 struct fsi_slave *slave = to_fsi_slave(dev);
806 struct fsi_master *master = slave->master;
807
808 if (!master->term)
809 return -ENODEV;
810
811 master->term(master, slave->link, slave->id);
812 return count;
813}
814
815static DEVICE_ATTR_WO(send_term);
816
817static ssize_t slave_send_echo_show(struct device *dev,
818 struct device_attribute *attr,
819 char *buf)
820{
821 struct fsi_slave *slave = to_fsi_slave(dev);
822
823 return sprintf(buf, "%u\n", slave->t_send_delay);
824}
825
826static ssize_t slave_send_echo_store(struct device *dev,
827 struct device_attribute *attr, const char *buf, size_t count)
828{
829 struct fsi_slave *slave = to_fsi_slave(dev);
830 struct fsi_master *master = slave->master;
831 unsigned long val;
832 int rc;
833
834 if (kstrtoul(buf, 0, &val) < 0)
835 return -EINVAL;
836
837 if (val < 1 || val > 16)
838 return -EINVAL;
839
840 if (!master->link_config)
841 return -ENXIO;
842
843 /* Current HW mandates that send and echo delay are identical */
844 slave->t_send_delay = val;
845 slave->t_echo_delay = val;
846
847 rc = fsi_slave_set_smode(slave);
848 if (rc < 0)
849 return rc;
850 if (master->link_config)
851 master->link_config(master, slave->link,
852 slave->t_send_delay,
853 slave->t_echo_delay);
854
855 return count;
856}
857
858static DEVICE_ATTR(send_echo_delays, 0600,
859 slave_send_echo_show, slave_send_echo_store);
860
861static ssize_t chip_id_show(struct device *dev,
862 struct device_attribute *attr,
863 char *buf)
864{
865 struct fsi_slave *slave = to_fsi_slave(dev);
866
867 return sprintf(buf, "%d\n", slave->chip_id);
868}
869
870static DEVICE_ATTR_RO(chip_id);
871
872static ssize_t cfam_id_show(struct device *dev,
873 struct device_attribute *attr,
874 char *buf)
875{
876 struct fsi_slave *slave = to_fsi_slave(dev);
877
878 return sprintf(buf, "0x%x\n", slave->cfam_id);
879}
880
881static DEVICE_ATTR_RO(cfam_id);
882
883static struct attribute *cfam_attr[] = {
884 &dev_attr_send_echo_delays.attr,
885 &dev_attr_chip_id.attr,
886 &dev_attr_cfam_id.attr,
887 &dev_attr_send_term.attr,
888 NULL,
889};
890
891static const struct attribute_group cfam_attr_group = {
892 .attrs = cfam_attr,
893};
894
895static const struct attribute_group *cfam_attr_groups[] = {
896 &cfam_attr_group,
897 NULL,
898};
899
900static char *cfam_devnode(struct device *dev, umode_t *mode,
901 kuid_t *uid, kgid_t *gid)
902{
903 struct fsi_slave *slave = to_fsi_slave(dev);
904
905#ifdef CONFIG_FSI_NEW_DEV_NODE
906 return kasprintf(GFP_KERNEL, "fsi/cfam%d", slave->cdev_idx);
907#else
908 return kasprintf(GFP_KERNEL, "cfam%d", slave->cdev_idx);
909#endif
910}
911
912static const struct device_type cfam_type = {
913 .name = "cfam",
914 .devnode = cfam_devnode,
915 .groups = cfam_attr_groups
916};
917
918static char *fsi_cdev_devnode(struct device *dev, umode_t *mode,
919 kuid_t *uid, kgid_t *gid)
920{
921#ifdef CONFIG_FSI_NEW_DEV_NODE
922 return kasprintf(GFP_KERNEL, "fsi/%s", dev_name(dev));
923#else
924 return kasprintf(GFP_KERNEL, "%s", dev_name(dev));
925#endif
926}
927
928const struct device_type fsi_cdev_type = {
929 .name = "fsi-cdev",
930 .devnode = fsi_cdev_devnode,
931};
932EXPORT_SYMBOL_GPL(fsi_cdev_type);
933
934/* Backward compatible /dev/ numbering in "old style" mode */
935static int fsi_adjust_index(int index)
936{
937#ifdef CONFIG_FSI_NEW_DEV_NODE
938 return index;
939#else
940 return index + 1;
941#endif
942}
943
944static int __fsi_get_new_minor(struct fsi_slave *slave, enum fsi_dev_type type,
945 dev_t *out_dev, int *out_index)
946{
947 int cid = slave->chip_id;
948 int id;
949
950 /* Check if we qualify for legacy numbering */
951 if (cid >= 0 && cid < 16 && type < 4) {
952 /* Try reserving the legacy number */
953 id = (cid << 4) | type;
954 id = ida_simple_get(&fsi_minor_ida, id, id + 1, GFP_KERNEL);
955 if (id >= 0) {
956 *out_index = fsi_adjust_index(cid);
957 *out_dev = fsi_base_dev + id;
958 return 0;
959 }
960 /* Other failure */
961 if (id != -ENOSPC)
962 return id;
963 /* Fallback to non-legacy allocation */
964 }
965 id = ida_simple_get(&fsi_minor_ida, FSI_CHAR_LEGACY_TOP,
966 FSI_CHAR_MAX_DEVICES, GFP_KERNEL);
967 if (id < 0)
968 return id;
969 *out_index = fsi_adjust_index(id);
970 *out_dev = fsi_base_dev + id;
971 return 0;
972}
973
974int fsi_get_new_minor(struct fsi_device *fdev, enum fsi_dev_type type,
975 dev_t *out_dev, int *out_index)
976{
977 return __fsi_get_new_minor(fdev->slave, type, out_dev, out_index);
978}
979EXPORT_SYMBOL_GPL(fsi_get_new_minor);
980
981void fsi_free_minor(dev_t dev)
982{
983 ida_simple_remove(&fsi_minor_ida, MINOR(dev));
984}
985EXPORT_SYMBOL_GPL(fsi_free_minor);
986
987static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
988{
989 uint32_t cfam_id;
990 struct fsi_slave *slave;
991 uint8_t crc;
992 __be32 data, llmode, slbus;
993 int rc;
994
995 /* Currently, we only support single slaves on a link, and use the
996 * full 23-bit address range
997 */
998 if (id != 0)
999 return -EINVAL;
1000
1001 rc = fsi_master_read(master, link, id, 0, &data, sizeof(data));
1002 if (rc) {
1003 dev_dbg(&master->dev, "can't read slave %02x:%02x %d\n",
1004 link, id, rc);
1005 return -ENODEV;
1006 }
1007 cfam_id = be32_to_cpu(data);
1008
1009 crc = crc4(0, cfam_id, 32);
1010 if (crc) {
1011 trace_fsi_slave_invalid_cfam(master, link, cfam_id);
1012 dev_warn(&master->dev, "slave %02x:%02x invalid cfam id CRC!\n",
1013 link, id);
1014 return -EIO;
1015 }
1016
1017 dev_dbg(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n",
1018 cfam_id, master->idx, link, id);
1019
1020 /* If we're behind a master that doesn't provide a self-running bus
1021 * clock, put the slave into async mode
1022 */
1023 if (master->flags & FSI_MASTER_FLAG_SWCLOCK) {
1024 llmode = cpu_to_be32(FSI_LLMODE_ASYNC);
1025 rc = fsi_master_write(master, link, id,
1026 FSI_SLAVE_BASE + FSI_LLMODE,
1027 &llmode, sizeof(llmode));
1028 if (rc)
1029 dev_warn(&master->dev,
1030 "can't set llmode on slave:%02x:%02x %d\n",
1031 link, id, rc);
1032 }
1033
1034 /* We can communicate with a slave; create the slave device and
1035 * register.
1036 */
1037 slave = kzalloc(sizeof(*slave), GFP_KERNEL);
1038 if (!slave)
1039 return -ENOMEM;
1040
1041 dev_set_name(&slave->dev, "slave@%02x:%02x", link, id);
1042 slave->dev.type = &cfam_type;
1043 slave->dev.parent = &master->dev;
1044 slave->dev.of_node = fsi_slave_find_of_node(master, link, id);
1045 slave->dev.release = fsi_slave_release;
1046 device_initialize(&slave->dev);
1047 slave->cfam_id = cfam_id;
1048 slave->master = master;
1049 slave->link = link;
1050 slave->id = id;
1051 slave->size = FSI_SLAVE_SIZE_23b;
1052 slave->t_send_delay = 16;
1053 slave->t_echo_delay = 16;
1054
1055 /* Get chip ID if any */
1056 slave->chip_id = -1;
1057 if (slave->dev.of_node) {
1058 uint32_t prop;
1059 if (!of_property_read_u32(slave->dev.of_node, "chip-id", &prop))
1060 slave->chip_id = prop;
1061
1062 }
1063
1064 slbus = cpu_to_be32(FSI_SLBUS_FORCE);
1065 rc = fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SLBUS,
1066 &slbus, sizeof(slbus));
1067 if (rc)
1068 dev_warn(&master->dev,
1069 "can't set slbus on slave:%02x:%02x %d\n", link, id,
1070 rc);
1071
1072 rc = fsi_slave_set_smode(slave);
1073 if (rc) {
1074 dev_warn(&master->dev,
1075 "can't set smode on slave:%02x:%02x %d\n",
1076 link, id, rc);
1077 goto err_free;
1078 }
1079
1080 /* Allocate a minor in the FSI space */
1081 rc = __fsi_get_new_minor(slave, fsi_dev_cfam, &slave->dev.devt,
1082 &slave->cdev_idx);
1083 if (rc)
1084 goto err_free;
1085
1086 trace_fsi_slave_init(slave);
1087
1088 /* Create chardev for userspace access */
1089 cdev_init(&slave->cdev, &cfam_fops);
1090 rc = cdev_device_add(&slave->cdev, &slave->dev);
1091 if (rc) {
1092 dev_err(&slave->dev, "Error %d creating slave device\n", rc);
1093 goto err_free_ida;
1094 }
1095
1096 /* Now that we have the cdev registered with the core, any fatal
1097 * failures beyond this point will need to clean up through
1098 * cdev_device_del(). Fortunately though, nothing past here is fatal.
1099 */
1100
1101 if (master->link_config)
1102 master->link_config(master, link,
1103 slave->t_send_delay,
1104 slave->t_echo_delay);
1105
1106 /* Legacy raw file -> to be removed */
1107 rc = device_create_bin_file(&slave->dev, &fsi_slave_raw_attr);
1108 if (rc)
1109 dev_warn(&slave->dev, "failed to create raw attr: %d\n", rc);
1110
1111
1112 rc = fsi_slave_scan(slave);
1113 if (rc)
1114 dev_dbg(&master->dev, "failed during slave scan with: %d\n",
1115 rc);
1116
1117 return 0;
1118
1119err_free_ida:
1120 fsi_free_minor(slave->dev.devt);
1121err_free:
1122 of_node_put(slave->dev.of_node);
1123 kfree(slave);
1124 return rc;
1125}
1126
1127/* FSI master support */
1128static int fsi_check_access(uint32_t addr, size_t size)
1129{
1130 if (size == 4) {
1131 if (addr & 0x3)
1132 return -EINVAL;
1133 } else if (size == 2) {
1134 if (addr & 0x1)
1135 return -EINVAL;
1136 } else if (size != 1)
1137 return -EINVAL;
1138
1139 return 0;
1140}
1141
1142static int fsi_master_read(struct fsi_master *master, int link,
1143 uint8_t slave_id, uint32_t addr, void *val, size_t size)
1144{
1145 int rc;
1146
1147 trace_fsi_master_read(master, link, slave_id, addr, size);
1148
1149 rc = fsi_check_access(addr, size);
1150 if (!rc)
1151 rc = master->read(master, link, slave_id, addr, val, size);
1152
1153 trace_fsi_master_rw_result(master, link, slave_id, addr, size,
1154 false, val, rc);
1155
1156 return rc;
1157}
1158
1159static int fsi_master_write(struct fsi_master *master, int link,
1160 uint8_t slave_id, uint32_t addr, const void *val, size_t size)
1161{
1162 int rc;
1163
1164 trace_fsi_master_write(master, link, slave_id, addr, size, val);
1165
1166 rc = fsi_check_access(addr, size);
1167 if (!rc)
1168 rc = master->write(master, link, slave_id, addr, val, size);
1169
1170 trace_fsi_master_rw_result(master, link, slave_id, addr, size,
1171 true, val, rc);
1172
1173 return rc;
1174}
1175
1176static int fsi_master_link_disable(struct fsi_master *master, int link)
1177{
1178 if (master->link_enable)
1179 return master->link_enable(master, link, false);
1180
1181 return 0;
1182}
1183
1184static int fsi_master_link_enable(struct fsi_master *master, int link)
1185{
1186 if (master->link_enable)
1187 return master->link_enable(master, link, true);
1188
1189 return 0;
1190}
1191
1192/*
1193 * Issue a break command on this link
1194 */
1195static int fsi_master_break(struct fsi_master *master, int link)
1196{
1197 int rc = 0;
1198
1199 trace_fsi_master_break(master, link);
1200
1201 if (master->send_break)
1202 rc = master->send_break(master, link);
1203 if (master->link_config)
1204 master->link_config(master, link, 16, 16);
1205
1206 return rc;
1207}
1208
1209static int fsi_master_scan(struct fsi_master *master)
1210{
1211 int link, rc;
1212
1213 for (link = 0; link < master->n_links; link++) {
1214 rc = fsi_master_link_enable(master, link);
1215 if (rc) {
1216 dev_dbg(&master->dev,
1217 "enable link %d failed: %d\n", link, rc);
1218 continue;
1219 }
1220 rc = fsi_master_break(master, link);
1221 if (rc) {
1222 fsi_master_link_disable(master, link);
1223 dev_dbg(&master->dev,
1224 "break to link %d failed: %d\n", link, rc);
1225 continue;
1226 }
1227
1228 rc = fsi_slave_init(master, link, 0);
1229 if (rc)
1230 fsi_master_link_disable(master, link);
1231 }
1232
1233 return 0;
1234}
1235
1236static int fsi_slave_remove_device(struct device *dev, void *arg)
1237{
1238 device_unregister(dev);
1239 return 0;
1240}
1241
1242static int fsi_master_remove_slave(struct device *dev, void *arg)
1243{
1244 struct fsi_slave *slave = to_fsi_slave(dev);
1245
1246 device_for_each_child(dev, NULL, fsi_slave_remove_device);
1247 cdev_device_del(&slave->cdev, &slave->dev);
1248 put_device(dev);
1249 return 0;
1250}
1251
1252static void fsi_master_unscan(struct fsi_master *master)
1253{
1254 device_for_each_child(&master->dev, NULL, fsi_master_remove_slave);
1255}
1256
1257int fsi_master_rescan(struct fsi_master *master)
1258{
1259 int rc;
1260
1261 mutex_lock(&master->scan_lock);
1262 fsi_master_unscan(master);
1263 rc = fsi_master_scan(master);
1264 mutex_unlock(&master->scan_lock);
1265
1266 return rc;
1267}
1268EXPORT_SYMBOL_GPL(fsi_master_rescan);
1269
1270static ssize_t master_rescan_store(struct device *dev,
1271 struct device_attribute *attr, const char *buf, size_t count)
1272{
1273 struct fsi_master *master = to_fsi_master(dev);
1274 int rc;
1275
1276 rc = fsi_master_rescan(master);
1277 if (rc < 0)
1278 return rc;
1279
1280 return count;
1281}
1282
1283static DEVICE_ATTR(rescan, 0200, NULL, master_rescan_store);
1284
1285static ssize_t master_break_store(struct device *dev,
1286 struct device_attribute *attr, const char *buf, size_t count)
1287{
1288 struct fsi_master *master = to_fsi_master(dev);
1289
1290 fsi_master_break(master, 0);
1291
1292 return count;
1293}
1294
1295static DEVICE_ATTR(break, 0200, NULL, master_break_store);
1296
1297static struct attribute *master_attrs[] = {
1298 &dev_attr_break.attr,
1299 &dev_attr_rescan.attr,
1300 NULL
1301};
1302
1303ATTRIBUTE_GROUPS(master);
1304
1305static struct class fsi_master_class = {
1306 .name = "fsi-master",
1307 .dev_groups = master_groups,
1308};
1309
1310int fsi_master_register(struct fsi_master *master)
1311{
1312 int rc;
1313 struct device_node *np;
1314
1315 mutex_init(&master->scan_lock);
1316 master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL);
1317 if (master->idx < 0)
1318 return master->idx;
1319
1320 dev_set_name(&master->dev, "fsi%d", master->idx);
1321 master->dev.class = &fsi_master_class;
1322
1323 rc = device_register(&master->dev);
1324 if (rc) {
1325 ida_simple_remove(&master_ida, master->idx);
1326 return rc;
1327 }
1328
1329 np = dev_of_node(&master->dev);
1330 if (!of_property_read_bool(np, "no-scan-on-init")) {
1331 mutex_lock(&master->scan_lock);
1332 fsi_master_scan(master);
1333 mutex_unlock(&master->scan_lock);
1334 }
1335
1336 return 0;
1337}
1338EXPORT_SYMBOL_GPL(fsi_master_register);
1339
1340void fsi_master_unregister(struct fsi_master *master)
1341{
1342 if (master->idx >= 0) {
1343 ida_simple_remove(&master_ida, master->idx);
1344 master->idx = -1;
1345 }
1346
1347 mutex_lock(&master->scan_lock);
1348 fsi_master_unscan(master);
1349 mutex_unlock(&master->scan_lock);
1350 device_unregister(&master->dev);
1351}
1352EXPORT_SYMBOL_GPL(fsi_master_unregister);
1353
1354/* FSI core & Linux bus type definitions */
1355
1356static int fsi_bus_match(struct device *dev, struct device_driver *drv)
1357{
1358 struct fsi_device *fsi_dev = to_fsi_dev(dev);
1359 struct fsi_driver *fsi_drv = to_fsi_drv(drv);
1360 const struct fsi_device_id *id;
1361
1362 if (!fsi_drv->id_table)
1363 return 0;
1364
1365 for (id = fsi_drv->id_table; id->engine_type; id++) {
1366 if (id->engine_type != fsi_dev->engine_type)
1367 continue;
1368 if (id->version == FSI_VERSION_ANY ||
1369 id->version == fsi_dev->version)
1370 return 1;
1371 }
1372
1373 return 0;
1374}
1375
1376int fsi_driver_register(struct fsi_driver *fsi_drv)
1377{
1378 if (!fsi_drv)
1379 return -EINVAL;
1380 if (!fsi_drv->id_table)
1381 return -EINVAL;
1382
1383 return driver_register(&fsi_drv->drv);
1384}
1385EXPORT_SYMBOL_GPL(fsi_driver_register);
1386
1387void fsi_driver_unregister(struct fsi_driver *fsi_drv)
1388{
1389 driver_unregister(&fsi_drv->drv);
1390}
1391EXPORT_SYMBOL_GPL(fsi_driver_unregister);
1392
1393struct bus_type fsi_bus_type = {
1394 .name = "fsi",
1395 .match = fsi_bus_match,
1396};
1397EXPORT_SYMBOL_GPL(fsi_bus_type);
1398
1399static int __init fsi_init(void)
1400{
1401 int rc;
1402
1403 rc = alloc_chrdev_region(&fsi_base_dev, 0, FSI_CHAR_MAX_DEVICES, "fsi");
1404 if (rc)
1405 return rc;
1406 rc = bus_register(&fsi_bus_type);
1407 if (rc)
1408 goto fail_bus;
1409
1410 rc = class_register(&fsi_master_class);
1411 if (rc)
1412 goto fail_class;
1413
1414 return 0;
1415
1416 fail_class:
1417 bus_unregister(&fsi_bus_type);
1418 fail_bus:
1419 unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES);
1420 return rc;
1421}
1422postcore_initcall(fsi_init);
1423
1424static void fsi_exit(void)
1425{
1426 class_unregister(&fsi_master_class);
1427 bus_unregister(&fsi_bus_type);
1428 unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES);
1429 ida_destroy(&fsi_minor_ida);
1430}
1431module_exit(fsi_exit);
1432module_param(discard_errors, int, 0664);
1433MODULE_LICENSE("GPL");
1434MODULE_PARM_DESC(discard_errors, "Don't invoke error handling on bus accesses");