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[mirror_ubuntu-hirsute-kernel.git] / drivers / fsi / fsi-core.c
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
43 static 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_SLBUS 0x30 /* W : LBUS Ownership */
54 #define FSI_LLMODE 0x100 /* R/W: Link layer mode register */
55
56 /*
57 * SMODE fields
58 */
59 #define FSI_SMODE_WSC 0x80000000 /* Warm start done */
60 #define FSI_SMODE_ECRC 0x20000000 /* Hw CRC check */
61 #define FSI_SMODE_SID_SHIFT 24 /* ID shift */
62 #define FSI_SMODE_SID_MASK 3 /* ID Mask */
63 #define FSI_SMODE_ED_SHIFT 20 /* Echo delay shift */
64 #define FSI_SMODE_ED_MASK 0xf /* Echo delay mask */
65 #define FSI_SMODE_SD_SHIFT 16 /* Send delay shift */
66 #define FSI_SMODE_SD_MASK 0xf /* Send delay mask */
67 #define FSI_SMODE_LBCRR_SHIFT 8 /* Clk ratio shift */
68 #define FSI_SMODE_LBCRR_MASK 0xf /* Clk ratio mask */
69
70 /*
71 * SLBUS fields
72 */
73 #define FSI_SLBUS_FORCE 0x80000000 /* Force LBUS ownership */
74
75 /*
76 * LLMODE fields
77 */
78 #define FSI_LLMODE_ASYNC 0x1
79
80 #define FSI_SLAVE_SIZE_23b 0x800000
81
82 static DEFINE_IDA(master_ida);
83
84 struct fsi_slave {
85 struct device dev;
86 struct fsi_master *master;
87 struct cdev cdev;
88 int cdev_idx;
89 int id; /* FSI address */
90 int link; /* FSI link# */
91 u32 cfam_id;
92 int chip_id;
93 uint32_t size; /* size of slave address space */
94 u8 t_send_delay;
95 u8 t_echo_delay;
96 };
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
101 static const int slave_retries = 2;
102 static int discard_errors;
103
104 static dev_t fsi_base_dev;
105 static 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
111 static int fsi_master_read(struct fsi_master *master, int link,
112 uint8_t slave_id, uint32_t addr, void *val, size_t size);
113 static int fsi_master_write(struct fsi_master *master, int link,
114 uint8_t slave_id, uint32_t addr, const void *val, size_t size);
115 static 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 */
134 int 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 }
142 EXPORT_SYMBOL_GPL(fsi_device_read);
143
144 int 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 }
152 EXPORT_SYMBOL_GPL(fsi_device_write);
153
154 int 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
161 static 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
169 static 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 */
185 static 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
209 static 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 */
238 static 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 */
244 static 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 */
250 static 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 */
256 static inline uint32_t fsi_smode_sid(int x)
257 {
258 return (x & FSI_SMODE_SID_MASK) << FSI_SMODE_SID_SHIFT;
259 }
260
261 static 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
269 static 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
285 static 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 &reg, 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
345 int 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 }
368 EXPORT_SYMBOL_GPL(fsi_slave_read);
369
370 int 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 }
393 EXPORT_SYMBOL_GPL(fsi_slave_write);
394
395 extern int 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 }
407 EXPORT_SYMBOL_GPL(fsi_slave_claim_range);
408
409 extern void fsi_slave_release_range(struct fsi_slave *slave,
410 uint32_t addr, uint32_t size)
411 {
412 }
413 EXPORT_SYMBOL_GPL(fsi_slave_release_range);
414
415 static 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 */
449 static 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
466 static 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 dev_dbg(&slave->dev,
528 "engine[%i]: type %x, version %x, addr %x size %x\n",
529 dev->unit, dev->engine_type, version,
530 dev->addr, dev->size);
531
532 dev_set_name(&dev->dev, "%02x:%02x:%02x:%02x",
533 slave->master->idx, slave->link,
534 slave->id, i - 2);
535 dev->dev.of_node = fsi_device_find_of_node(dev);
536
537 rc = device_register(&dev->dev);
538 if (rc) {
539 dev_warn(&slave->dev, "add failed: %d\n", rc);
540 put_device(&dev->dev);
541 }
542 }
543
544 engine_addr += slots * engine_page_size;
545
546 if (!(conf & FSI_SLAVE_CONF_NEXT_MASK))
547 break;
548 }
549
550 return 0;
551 }
552
553 static unsigned long aligned_access_size(size_t offset, size_t count)
554 {
555 unsigned long offset_unit, count_unit;
556
557 /* Criteria:
558 *
559 * 1. Access size must be less than or equal to the maximum access
560 * width or the highest power-of-two factor of offset
561 * 2. Access size must be less than or equal to the amount specified by
562 * count
563 *
564 * The access width is optimal if we can calculate 1 to be strictly
565 * equal while still satisfying 2.
566 */
567
568 /* Find 1 by the bottom bit of offset (with a 4 byte access cap) */
569 offset_unit = BIT(__builtin_ctzl(offset | 4));
570
571 /* Find 2 by the top bit of count */
572 count_unit = BIT(8 * sizeof(unsigned long) - 1 - __builtin_clzl(count));
573
574 /* Constrain the maximum access width to the minimum of both criteria */
575 return BIT(__builtin_ctzl(offset_unit | count_unit));
576 }
577
578 static ssize_t fsi_slave_sysfs_raw_read(struct file *file,
579 struct kobject *kobj, struct bin_attribute *attr, char *buf,
580 loff_t off, size_t count)
581 {
582 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
583 size_t total_len, read_len;
584 int rc;
585
586 if (off < 0)
587 return -EINVAL;
588
589 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
590 return -EINVAL;
591
592 for (total_len = 0; total_len < count; total_len += read_len) {
593 read_len = aligned_access_size(off, count - total_len);
594
595 rc = fsi_slave_read(slave, off, buf + total_len, read_len);
596 if (rc)
597 return rc;
598
599 off += read_len;
600 }
601
602 return count;
603 }
604
605 static ssize_t fsi_slave_sysfs_raw_write(struct file *file,
606 struct kobject *kobj, struct bin_attribute *attr,
607 char *buf, loff_t off, size_t count)
608 {
609 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
610 size_t total_len, write_len;
611 int rc;
612
613 if (off < 0)
614 return -EINVAL;
615
616 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
617 return -EINVAL;
618
619 for (total_len = 0; total_len < count; total_len += write_len) {
620 write_len = aligned_access_size(off, count - total_len);
621
622 rc = fsi_slave_write(slave, off, buf + total_len, write_len);
623 if (rc)
624 return rc;
625
626 off += write_len;
627 }
628
629 return count;
630 }
631
632 static const struct bin_attribute fsi_slave_raw_attr = {
633 .attr = {
634 .name = "raw",
635 .mode = 0600,
636 },
637 .size = 0,
638 .read = fsi_slave_sysfs_raw_read,
639 .write = fsi_slave_sysfs_raw_write,
640 };
641
642 static void fsi_slave_release(struct device *dev)
643 {
644 struct fsi_slave *slave = to_fsi_slave(dev);
645
646 fsi_free_minor(slave->dev.devt);
647 of_node_put(dev->of_node);
648 kfree(slave);
649 }
650
651 static bool fsi_slave_node_matches(struct device_node *np,
652 int link, uint8_t id)
653 {
654 unsigned int len, na, ns;
655 const __be32 *prop;
656
657 na = of_n_addr_cells(np);
658 ns = of_n_size_cells(np);
659
660 /* Ensure we have the correct format for addresses and sizes in
661 * reg properties
662 */
663 if (na != 2 || ns != 0)
664 return false;
665
666 prop = of_get_property(np, "reg", &len);
667 if (!prop || len != 8)
668 return false;
669
670 return (of_read_number(prop, 1) == link) &&
671 (of_read_number(prop + 1, 1) == id);
672 }
673
674 /* Find a matching node for the slave at (link, id). Returns NULL if none
675 * found, or a matching node with refcount already incremented.
676 */
677 static struct device_node *fsi_slave_find_of_node(struct fsi_master *master,
678 int link, uint8_t id)
679 {
680 struct device_node *parent, *np;
681
682 parent = dev_of_node(&master->dev);
683 if (!parent)
684 return NULL;
685
686 for_each_child_of_node(parent, np) {
687 if (fsi_slave_node_matches(np, link, id))
688 return np;
689 }
690
691 return NULL;
692 }
693
694 static ssize_t cfam_read(struct file *filep, char __user *buf, size_t count,
695 loff_t *offset)
696 {
697 struct fsi_slave *slave = filep->private_data;
698 size_t total_len, read_len;
699 loff_t off = *offset;
700 ssize_t rc;
701
702 if (off < 0)
703 return -EINVAL;
704
705 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
706 return -EINVAL;
707
708 for (total_len = 0; total_len < count; total_len += read_len) {
709 __be32 data;
710
711 read_len = min_t(size_t, count, 4);
712 read_len -= off & 0x3;
713
714 rc = fsi_slave_read(slave, off, &data, read_len);
715 if (rc)
716 goto fail;
717 rc = copy_to_user(buf + total_len, &data, read_len);
718 if (rc) {
719 rc = -EFAULT;
720 goto fail;
721 }
722 off += read_len;
723 }
724 rc = count;
725 fail:
726 *offset = off;
727 return count;
728 }
729
730 static ssize_t cfam_write(struct file *filep, const char __user *buf,
731 size_t count, loff_t *offset)
732 {
733 struct fsi_slave *slave = filep->private_data;
734 size_t total_len, write_len;
735 loff_t off = *offset;
736 ssize_t rc;
737
738
739 if (off < 0)
740 return -EINVAL;
741
742 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
743 return -EINVAL;
744
745 for (total_len = 0; total_len < count; total_len += write_len) {
746 __be32 data;
747
748 write_len = min_t(size_t, count, 4);
749 write_len -= off & 0x3;
750
751 rc = copy_from_user(&data, buf + total_len, write_len);
752 if (rc) {
753 rc = -EFAULT;
754 goto fail;
755 }
756 rc = fsi_slave_write(slave, off, &data, write_len);
757 if (rc)
758 goto fail;
759 off += write_len;
760 }
761 rc = count;
762 fail:
763 *offset = off;
764 return count;
765 }
766
767 static loff_t cfam_llseek(struct file *file, loff_t offset, int whence)
768 {
769 switch (whence) {
770 case SEEK_CUR:
771 break;
772 case SEEK_SET:
773 file->f_pos = offset;
774 break;
775 default:
776 return -EINVAL;
777 }
778
779 return offset;
780 }
781
782 static int cfam_open(struct inode *inode, struct file *file)
783 {
784 struct fsi_slave *slave = container_of(inode->i_cdev, struct fsi_slave, cdev);
785
786 file->private_data = slave;
787
788 return 0;
789 }
790
791 static const struct file_operations cfam_fops = {
792 .owner = THIS_MODULE,
793 .open = cfam_open,
794 .llseek = cfam_llseek,
795 .read = cfam_read,
796 .write = cfam_write,
797 };
798
799 static ssize_t send_term_store(struct device *dev,
800 struct device_attribute *attr,
801 const char *buf, size_t count)
802 {
803 struct fsi_slave *slave = to_fsi_slave(dev);
804 struct fsi_master *master = slave->master;
805
806 if (!master->term)
807 return -ENODEV;
808
809 master->term(master, slave->link, slave->id);
810 return count;
811 }
812
813 static DEVICE_ATTR_WO(send_term);
814
815 static ssize_t slave_send_echo_show(struct device *dev,
816 struct device_attribute *attr,
817 char *buf)
818 {
819 struct fsi_slave *slave = to_fsi_slave(dev);
820
821 return sprintf(buf, "%u\n", slave->t_send_delay);
822 }
823
824 static ssize_t slave_send_echo_store(struct device *dev,
825 struct device_attribute *attr, const char *buf, size_t count)
826 {
827 struct fsi_slave *slave = to_fsi_slave(dev);
828 struct fsi_master *master = slave->master;
829 unsigned long val;
830 int rc;
831
832 if (kstrtoul(buf, 0, &val) < 0)
833 return -EINVAL;
834
835 if (val < 1 || val > 16)
836 return -EINVAL;
837
838 if (!master->link_config)
839 return -ENXIO;
840
841 /* Current HW mandates that send and echo delay are identical */
842 slave->t_send_delay = val;
843 slave->t_echo_delay = val;
844
845 rc = fsi_slave_set_smode(slave);
846 if (rc < 0)
847 return rc;
848 if (master->link_config)
849 master->link_config(master, slave->link,
850 slave->t_send_delay,
851 slave->t_echo_delay);
852
853 return count;
854 }
855
856 static DEVICE_ATTR(send_echo_delays, 0600,
857 slave_send_echo_show, slave_send_echo_store);
858
859 static ssize_t chip_id_show(struct device *dev,
860 struct device_attribute *attr,
861 char *buf)
862 {
863 struct fsi_slave *slave = to_fsi_slave(dev);
864
865 return sprintf(buf, "%d\n", slave->chip_id);
866 }
867
868 static DEVICE_ATTR_RO(chip_id);
869
870 static ssize_t cfam_id_show(struct device *dev,
871 struct device_attribute *attr,
872 char *buf)
873 {
874 struct fsi_slave *slave = to_fsi_slave(dev);
875
876 return sprintf(buf, "0x%x\n", slave->cfam_id);
877 }
878
879 static DEVICE_ATTR_RO(cfam_id);
880
881 static struct attribute *cfam_attr[] = {
882 &dev_attr_send_echo_delays.attr,
883 &dev_attr_chip_id.attr,
884 &dev_attr_cfam_id.attr,
885 &dev_attr_send_term.attr,
886 NULL,
887 };
888
889 static const struct attribute_group cfam_attr_group = {
890 .attrs = cfam_attr,
891 };
892
893 static const struct attribute_group *cfam_attr_groups[] = {
894 &cfam_attr_group,
895 NULL,
896 };
897
898 static char *cfam_devnode(struct device *dev, umode_t *mode,
899 kuid_t *uid, kgid_t *gid)
900 {
901 struct fsi_slave *slave = to_fsi_slave(dev);
902
903 #ifdef CONFIG_FSI_NEW_DEV_NODE
904 return kasprintf(GFP_KERNEL, "fsi/cfam%d", slave->cdev_idx);
905 #else
906 return kasprintf(GFP_KERNEL, "cfam%d", slave->cdev_idx);
907 #endif
908 }
909
910 static const struct device_type cfam_type = {
911 .name = "cfam",
912 .devnode = cfam_devnode,
913 .groups = cfam_attr_groups
914 };
915
916 static char *fsi_cdev_devnode(struct device *dev, umode_t *mode,
917 kuid_t *uid, kgid_t *gid)
918 {
919 #ifdef CONFIG_FSI_NEW_DEV_NODE
920 return kasprintf(GFP_KERNEL, "fsi/%s", dev_name(dev));
921 #else
922 return kasprintf(GFP_KERNEL, "%s", dev_name(dev));
923 #endif
924 }
925
926 const struct device_type fsi_cdev_type = {
927 .name = "fsi-cdev",
928 .devnode = fsi_cdev_devnode,
929 };
930 EXPORT_SYMBOL_GPL(fsi_cdev_type);
931
932 /* Backward compatible /dev/ numbering in "old style" mode */
933 static int fsi_adjust_index(int index)
934 {
935 #ifdef CONFIG_FSI_NEW_DEV_NODE
936 return index;
937 #else
938 return index + 1;
939 #endif
940 }
941
942 static int __fsi_get_new_minor(struct fsi_slave *slave, enum fsi_dev_type type,
943 dev_t *out_dev, int *out_index)
944 {
945 int cid = slave->chip_id;
946 int id;
947
948 /* Check if we qualify for legacy numbering */
949 if (cid >= 0 && cid < 16 && type < 4) {
950 /* Try reserving the legacy number */
951 id = (cid << 4) | type;
952 id = ida_simple_get(&fsi_minor_ida, id, id + 1, GFP_KERNEL);
953 if (id >= 0) {
954 *out_index = fsi_adjust_index(cid);
955 *out_dev = fsi_base_dev + id;
956 return 0;
957 }
958 /* Other failure */
959 if (id != -ENOSPC)
960 return id;
961 /* Fallback to non-legacy allocation */
962 }
963 id = ida_simple_get(&fsi_minor_ida, FSI_CHAR_LEGACY_TOP,
964 FSI_CHAR_MAX_DEVICES, GFP_KERNEL);
965 if (id < 0)
966 return id;
967 *out_index = fsi_adjust_index(id);
968 *out_dev = fsi_base_dev + id;
969 return 0;
970 }
971
972 int fsi_get_new_minor(struct fsi_device *fdev, enum fsi_dev_type type,
973 dev_t *out_dev, int *out_index)
974 {
975 return __fsi_get_new_minor(fdev->slave, type, out_dev, out_index);
976 }
977 EXPORT_SYMBOL_GPL(fsi_get_new_minor);
978
979 void fsi_free_minor(dev_t dev)
980 {
981 ida_simple_remove(&fsi_minor_ida, MINOR(dev));
982 }
983 EXPORT_SYMBOL_GPL(fsi_free_minor);
984
985 static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
986 {
987 uint32_t cfam_id;
988 struct fsi_slave *slave;
989 uint8_t crc;
990 __be32 data, llmode, slbus;
991 int rc;
992
993 /* Currently, we only support single slaves on a link, and use the
994 * full 23-bit address range
995 */
996 if (id != 0)
997 return -EINVAL;
998
999 rc = fsi_master_read(master, link, id, 0, &data, sizeof(data));
1000 if (rc) {
1001 dev_dbg(&master->dev, "can't read slave %02x:%02x %d\n",
1002 link, id, rc);
1003 return -ENODEV;
1004 }
1005 cfam_id = be32_to_cpu(data);
1006
1007 crc = crc4(0, cfam_id, 32);
1008 if (crc) {
1009 dev_warn(&master->dev, "slave %02x:%02x invalid cfam id CRC!\n",
1010 link, id);
1011 return -EIO;
1012 }
1013
1014 dev_dbg(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n",
1015 cfam_id, master->idx, link, id);
1016
1017 /* If we're behind a master that doesn't provide a self-running bus
1018 * clock, put the slave into async mode
1019 */
1020 if (master->flags & FSI_MASTER_FLAG_SWCLOCK) {
1021 llmode = cpu_to_be32(FSI_LLMODE_ASYNC);
1022 rc = fsi_master_write(master, link, id,
1023 FSI_SLAVE_BASE + FSI_LLMODE,
1024 &llmode, sizeof(llmode));
1025 if (rc)
1026 dev_warn(&master->dev,
1027 "can't set llmode on slave:%02x:%02x %d\n",
1028 link, id, rc);
1029 }
1030
1031 /* We can communicate with a slave; create the slave device and
1032 * register.
1033 */
1034 slave = kzalloc(sizeof(*slave), GFP_KERNEL);
1035 if (!slave)
1036 return -ENOMEM;
1037
1038 dev_set_name(&slave->dev, "slave@%02x:%02x", link, id);
1039 slave->dev.type = &cfam_type;
1040 slave->dev.parent = &master->dev;
1041 slave->dev.of_node = fsi_slave_find_of_node(master, link, id);
1042 slave->dev.release = fsi_slave_release;
1043 device_initialize(&slave->dev);
1044 slave->cfam_id = cfam_id;
1045 slave->master = master;
1046 slave->link = link;
1047 slave->id = id;
1048 slave->size = FSI_SLAVE_SIZE_23b;
1049 slave->t_send_delay = 16;
1050 slave->t_echo_delay = 16;
1051
1052 /* Get chip ID if any */
1053 slave->chip_id = -1;
1054 if (slave->dev.of_node) {
1055 uint32_t prop;
1056 if (!of_property_read_u32(slave->dev.of_node, "chip-id", &prop))
1057 slave->chip_id = prop;
1058
1059 }
1060
1061 slbus = cpu_to_be32(FSI_SLBUS_FORCE);
1062 rc = fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SLBUS,
1063 &slbus, sizeof(slbus));
1064 if (rc)
1065 dev_warn(&master->dev,
1066 "can't set slbus on slave:%02x:%02x %d\n", link, id,
1067 rc);
1068
1069 rc = fsi_slave_set_smode(slave);
1070 if (rc) {
1071 dev_warn(&master->dev,
1072 "can't set smode on slave:%02x:%02x %d\n",
1073 link, id, rc);
1074 goto err_free;
1075 }
1076
1077 /* Allocate a minor in the FSI space */
1078 rc = __fsi_get_new_minor(slave, fsi_dev_cfam, &slave->dev.devt,
1079 &slave->cdev_idx);
1080 if (rc)
1081 goto err_free;
1082
1083 /* Create chardev for userspace access */
1084 cdev_init(&slave->cdev, &cfam_fops);
1085 rc = cdev_device_add(&slave->cdev, &slave->dev);
1086 if (rc) {
1087 dev_err(&slave->dev, "Error %d creating slave device\n", rc);
1088 goto err_free_ida;
1089 }
1090
1091 /* Now that we have the cdev registered with the core, any fatal
1092 * failures beyond this point will need to clean up through
1093 * cdev_device_del(). Fortunately though, nothing past here is fatal.
1094 */
1095
1096 if (master->link_config)
1097 master->link_config(master, link,
1098 slave->t_send_delay,
1099 slave->t_echo_delay);
1100
1101 /* Legacy raw file -> to be removed */
1102 rc = device_create_bin_file(&slave->dev, &fsi_slave_raw_attr);
1103 if (rc)
1104 dev_warn(&slave->dev, "failed to create raw attr: %d\n", rc);
1105
1106
1107 rc = fsi_slave_scan(slave);
1108 if (rc)
1109 dev_dbg(&master->dev, "failed during slave scan with: %d\n",
1110 rc);
1111
1112 return 0;
1113
1114 err_free_ida:
1115 fsi_free_minor(slave->dev.devt);
1116 err_free:
1117 of_node_put(slave->dev.of_node);
1118 kfree(slave);
1119 return rc;
1120 }
1121
1122 /* FSI master support */
1123 static int fsi_check_access(uint32_t addr, size_t size)
1124 {
1125 if (size == 4) {
1126 if (addr & 0x3)
1127 return -EINVAL;
1128 } else if (size == 2) {
1129 if (addr & 0x1)
1130 return -EINVAL;
1131 } else if (size != 1)
1132 return -EINVAL;
1133
1134 return 0;
1135 }
1136
1137 static int fsi_master_read(struct fsi_master *master, int link,
1138 uint8_t slave_id, uint32_t addr, void *val, size_t size)
1139 {
1140 int rc;
1141
1142 trace_fsi_master_read(master, link, slave_id, addr, size);
1143
1144 rc = fsi_check_access(addr, size);
1145 if (!rc)
1146 rc = master->read(master, link, slave_id, addr, val, size);
1147
1148 trace_fsi_master_rw_result(master, link, slave_id, addr, size,
1149 false, val, rc);
1150
1151 return rc;
1152 }
1153
1154 static int fsi_master_write(struct fsi_master *master, int link,
1155 uint8_t slave_id, uint32_t addr, const void *val, size_t size)
1156 {
1157 int rc;
1158
1159 trace_fsi_master_write(master, link, slave_id, addr, size, val);
1160
1161 rc = fsi_check_access(addr, size);
1162 if (!rc)
1163 rc = master->write(master, link, slave_id, addr, val, size);
1164
1165 trace_fsi_master_rw_result(master, link, slave_id, addr, size,
1166 true, val, rc);
1167
1168 return rc;
1169 }
1170
1171 static int fsi_master_link_disable(struct fsi_master *master, int link)
1172 {
1173 if (master->link_enable)
1174 return master->link_enable(master, link, false);
1175
1176 return 0;
1177 }
1178
1179 static int fsi_master_link_enable(struct fsi_master *master, int link)
1180 {
1181 if (master->link_enable)
1182 return master->link_enable(master, link, true);
1183
1184 return 0;
1185 }
1186
1187 /*
1188 * Issue a break command on this link
1189 */
1190 static int fsi_master_break(struct fsi_master *master, int link)
1191 {
1192 int rc = 0;
1193
1194 trace_fsi_master_break(master, link);
1195
1196 if (master->send_break)
1197 rc = master->send_break(master, link);
1198 if (master->link_config)
1199 master->link_config(master, link, 16, 16);
1200
1201 return rc;
1202 }
1203
1204 static int fsi_master_scan(struct fsi_master *master)
1205 {
1206 int link, rc;
1207
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, 0);
1224 if (rc)
1225 fsi_master_link_disable(master, link);
1226 }
1227
1228 return 0;
1229 }
1230
1231 static int fsi_slave_remove_device(struct device *dev, void *arg)
1232 {
1233 device_unregister(dev);
1234 return 0;
1235 }
1236
1237 static 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(dev, NULL, fsi_slave_remove_device);
1242 cdev_device_del(&slave->cdev, &slave->dev);
1243 put_device(dev);
1244 return 0;
1245 }
1246
1247 static void fsi_master_unscan(struct fsi_master *master)
1248 {
1249 device_for_each_child(&master->dev, NULL, fsi_master_remove_slave);
1250 }
1251
1252 int fsi_master_rescan(struct fsi_master *master)
1253 {
1254 int rc;
1255
1256 mutex_lock(&master->scan_lock);
1257 fsi_master_unscan(master);
1258 rc = fsi_master_scan(master);
1259 mutex_unlock(&master->scan_lock);
1260
1261 return rc;
1262 }
1263 EXPORT_SYMBOL_GPL(fsi_master_rescan);
1264
1265 static ssize_t master_rescan_store(struct device *dev,
1266 struct device_attribute *attr, const char *buf, size_t count)
1267 {
1268 struct fsi_master *master = to_fsi_master(dev);
1269 int rc;
1270
1271 rc = fsi_master_rescan(master);
1272 if (rc < 0)
1273 return rc;
1274
1275 return count;
1276 }
1277
1278 static DEVICE_ATTR(rescan, 0200, NULL, master_rescan_store);
1279
1280 static ssize_t master_break_store(struct device *dev,
1281 struct device_attribute *attr, const char *buf, size_t count)
1282 {
1283 struct fsi_master *master = to_fsi_master(dev);
1284
1285 fsi_master_break(master, 0);
1286
1287 return count;
1288 }
1289
1290 static DEVICE_ATTR(break, 0200, NULL, master_break_store);
1291
1292 static struct attribute *master_attrs[] = {
1293 &dev_attr_break.attr,
1294 &dev_attr_rescan.attr,
1295 NULL
1296 };
1297
1298 ATTRIBUTE_GROUPS(master);
1299
1300 static struct class fsi_master_class = {
1301 .name = "fsi-master",
1302 .dev_groups = master_groups,
1303 };
1304
1305 int fsi_master_register(struct fsi_master *master)
1306 {
1307 int rc;
1308 struct device_node *np;
1309
1310 mutex_init(&master->scan_lock);
1311 master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL);
1312 dev_set_name(&master->dev, "fsi%d", master->idx);
1313 master->dev.class = &fsi_master_class;
1314
1315 rc = device_register(&master->dev);
1316 if (rc) {
1317 ida_simple_remove(&master_ida, master->idx);
1318 return rc;
1319 }
1320
1321 np = dev_of_node(&master->dev);
1322 if (!of_property_read_bool(np, "no-scan-on-init")) {
1323 mutex_lock(&master->scan_lock);
1324 fsi_master_scan(master);
1325 mutex_unlock(&master->scan_lock);
1326 }
1327
1328 return 0;
1329 }
1330 EXPORT_SYMBOL_GPL(fsi_master_register);
1331
1332 void fsi_master_unregister(struct fsi_master *master)
1333 {
1334 if (master->idx >= 0) {
1335 ida_simple_remove(&master_ida, master->idx);
1336 master->idx = -1;
1337 }
1338
1339 mutex_lock(&master->scan_lock);
1340 fsi_master_unscan(master);
1341 mutex_unlock(&master->scan_lock);
1342 device_unregister(&master->dev);
1343 }
1344 EXPORT_SYMBOL_GPL(fsi_master_unregister);
1345
1346 /* FSI core & Linux bus type definitions */
1347
1348 static int fsi_bus_match(struct device *dev, struct device_driver *drv)
1349 {
1350 struct fsi_device *fsi_dev = to_fsi_dev(dev);
1351 struct fsi_driver *fsi_drv = to_fsi_drv(drv);
1352 const struct fsi_device_id *id;
1353
1354 if (!fsi_drv->id_table)
1355 return 0;
1356
1357 for (id = fsi_drv->id_table; id->engine_type; id++) {
1358 if (id->engine_type != fsi_dev->engine_type)
1359 continue;
1360 if (id->version == FSI_VERSION_ANY ||
1361 id->version == fsi_dev->version)
1362 return 1;
1363 }
1364
1365 return 0;
1366 }
1367
1368 int fsi_driver_register(struct fsi_driver *fsi_drv)
1369 {
1370 if (!fsi_drv)
1371 return -EINVAL;
1372 if (!fsi_drv->id_table)
1373 return -EINVAL;
1374
1375 return driver_register(&fsi_drv->drv);
1376 }
1377 EXPORT_SYMBOL_GPL(fsi_driver_register);
1378
1379 void fsi_driver_unregister(struct fsi_driver *fsi_drv)
1380 {
1381 driver_unregister(&fsi_drv->drv);
1382 }
1383 EXPORT_SYMBOL_GPL(fsi_driver_unregister);
1384
1385 struct bus_type fsi_bus_type = {
1386 .name = "fsi",
1387 .match = fsi_bus_match,
1388 };
1389 EXPORT_SYMBOL_GPL(fsi_bus_type);
1390
1391 static int __init fsi_init(void)
1392 {
1393 int rc;
1394
1395 rc = alloc_chrdev_region(&fsi_base_dev, 0, FSI_CHAR_MAX_DEVICES, "fsi");
1396 if (rc)
1397 return rc;
1398 rc = bus_register(&fsi_bus_type);
1399 if (rc)
1400 goto fail_bus;
1401
1402 rc = class_register(&fsi_master_class);
1403 if (rc)
1404 goto fail_class;
1405
1406 return 0;
1407
1408 fail_class:
1409 bus_unregister(&fsi_bus_type);
1410 fail_bus:
1411 unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES);
1412 return rc;
1413 }
1414 postcore_initcall(fsi_init);
1415
1416 static void fsi_exit(void)
1417 {
1418 class_unregister(&fsi_master_class);
1419 bus_unregister(&fsi_bus_type);
1420 unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES);
1421 ida_destroy(&fsi_minor_ida);
1422 }
1423 module_exit(fsi_exit);
1424 module_param(discard_errors, int, 0664);
1425 MODULE_LICENSE("GPL");
1426 MODULE_PARM_DESC(discard_errors, "Don't invoke error handling on bus accesses");
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