1 // SPDX-License-Identifier: GPL-2.0-only
5 * Copyright (C) IBM Corporation 2016
10 * - s/cfam/chip (cfam_id -> chip_id etc...)
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>
19 #include <linux/of_address.h>
20 #include <linux/slab.h>
21 #include <linux/bitops.h>
22 #include <linux/cdev.h>
24 #include <linux/uaccess.h>
26 #include "fsi-master.h"
27 #include "fsi-slave.h"
29 #define CREATE_TRACE_POINTS
30 #include <trace/events/fsi.h>
32 #define FSI_SLAVE_CONF_NEXT_MASK GENMASK(31, 31)
33 #define FSI_SLAVE_CONF_SLOTS_MASK GENMASK(23, 16)
34 #define FSI_SLAVE_CONF_SLOTS_SHIFT 16
35 #define FSI_SLAVE_CONF_VERSION_MASK GENMASK(15, 12)
36 #define FSI_SLAVE_CONF_VERSION_SHIFT 12
37 #define FSI_SLAVE_CONF_TYPE_MASK GENMASK(11, 4)
38 #define FSI_SLAVE_CONF_TYPE_SHIFT 4
39 #define FSI_SLAVE_CONF_CRC_SHIFT 4
40 #define FSI_SLAVE_CONF_CRC_MASK GENMASK(3, 0)
41 #define FSI_SLAVE_CONF_DATA_BITS 28
43 #define FSI_PEEK_BASE 0x410
45 static const int engine_page_size = 0x400;
47 #define FSI_SLAVE_BASE 0x800
50 * FSI slave engine control register offsets
52 #define FSI_SMODE 0x0 /* R/W: Mode register */
53 #define FSI_SISC 0x8 /* R/W: Interrupt condition */
54 #define FSI_SSTAT 0x14 /* R : Slave status */
55 #define FSI_SLBUS 0x30 /* W : LBUS Ownership */
56 #define FSI_LLMODE 0x100 /* R/W: Link layer mode register */
61 #define FSI_SMODE_WSC 0x80000000 /* Warm start done */
62 #define FSI_SMODE_ECRC 0x20000000 /* Hw CRC check */
63 #define FSI_SMODE_SID_SHIFT 24 /* ID shift */
64 #define FSI_SMODE_SID_MASK 3 /* ID Mask */
65 #define FSI_SMODE_ED_SHIFT 20 /* Echo delay shift */
66 #define FSI_SMODE_ED_MASK 0xf /* Echo delay mask */
67 #define FSI_SMODE_SD_SHIFT 16 /* Send delay shift */
68 #define FSI_SMODE_SD_MASK 0xf /* Send delay mask */
69 #define FSI_SMODE_LBCRR_SHIFT 8 /* Clk ratio shift */
70 #define FSI_SMODE_LBCRR_MASK 0xf /* Clk ratio mask */
75 #define FSI_SLBUS_FORCE 0x80000000 /* Force LBUS ownership */
80 #define FSI_LLMODE_ASYNC 0x1
82 #define FSI_SLAVE_SIZE_23b 0x800000
84 static DEFINE_IDA(master_ida);
86 static const int slave_retries = 2;
87 static int discard_errors;
89 static dev_t fsi_base_dev;
90 static DEFINE_IDA(fsi_minor_ida);
91 #define FSI_CHAR_MAX_DEVICES 0x1000
93 /* Legacy /dev numbering: 4 devices per chip, 16 chips */
94 #define FSI_CHAR_LEGACY_TOP 64
96 static int fsi_master_read(struct fsi_master *master, int link,
97 uint8_t slave_id, uint32_t addr, void *val, size_t size);
98 static int fsi_master_write(struct fsi_master *master, int link,
99 uint8_t slave_id, uint32_t addr, const void *val, size_t size);
100 static int fsi_master_break(struct fsi_master *master, int link);
103 * fsi_device_read() / fsi_device_write() / fsi_device_peek()
105 * FSI endpoint-device support
107 * Read / write / peek accessors for a client
110 * dev: Structure passed to FSI client device drivers on probe().
111 * addr: FSI address of given device. Client should pass in its base address
112 * plus desired offset to access its register space.
113 * val: For read/peek this is the value read at the specified address. For
114 * write this is value to write to the specified address.
115 * The data in val must be FSI bus endian (big endian).
116 * size: Size in bytes of the operation. Sizes supported are 1, 2 and 4 bytes.
117 * Addresses must be aligned on size boundaries or an error will result.
119 int fsi_device_read(struct fsi_device *dev, uint32_t addr, void *val,
122 if (addr > dev->size || size > dev->size || addr > dev->size - size)
125 return fsi_slave_read(dev->slave, dev->addr + addr, val, size);
127 EXPORT_SYMBOL_GPL(fsi_device_read);
129 int fsi_device_write(struct fsi_device *dev, uint32_t addr, const void *val,
132 if (addr > dev->size || size > dev->size || addr > dev->size - size)
135 return fsi_slave_write(dev->slave, dev->addr + addr, val, size);
137 EXPORT_SYMBOL_GPL(fsi_device_write);
139 int fsi_device_peek(struct fsi_device *dev, void *val)
141 uint32_t addr = FSI_PEEK_BASE + ((dev->unit - 2) * sizeof(uint32_t));
143 return fsi_slave_read(dev->slave, addr, val, sizeof(uint32_t));
146 static void fsi_device_release(struct device *_device)
148 struct fsi_device *device = to_fsi_dev(_device);
150 of_node_put(device->dev.of_node);
154 static struct fsi_device *fsi_create_device(struct fsi_slave *slave)
156 struct fsi_device *dev;
158 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
162 dev->dev.parent = &slave->dev;
163 dev->dev.bus = &fsi_bus_type;
164 dev->dev.release = fsi_device_release;
169 /* FSI slave support */
170 static int fsi_slave_calc_addr(struct fsi_slave *slave, uint32_t *addrp,
173 uint32_t addr = *addrp;
176 if (addr > slave->size)
179 /* For 23 bit addressing, we encode the extra two bits in the slave
180 * id (and the slave's actual ID needs to be 0).
182 if (addr > 0x1fffff) {
185 id = (addr >> 21) & 0x3;
194 static int fsi_slave_report_and_clear_errors(struct fsi_slave *slave)
196 struct fsi_master *master = slave->master;
204 rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SISC,
209 rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SSTAT,
210 &stat, sizeof(stat));
214 dev_dbg(&slave->dev, "status: 0x%08x, sisc: 0x%08x\n",
215 be32_to_cpu(stat), be32_to_cpu(irq));
217 /* clear interrupts */
218 return fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SISC,
222 /* Encode slave local bus echo delay */
223 static inline uint32_t fsi_smode_echodly(int x)
225 return (x & FSI_SMODE_ED_MASK) << FSI_SMODE_ED_SHIFT;
228 /* Encode slave local bus send delay */
229 static inline uint32_t fsi_smode_senddly(int x)
231 return (x & FSI_SMODE_SD_MASK) << FSI_SMODE_SD_SHIFT;
234 /* Encode slave local bus clock rate ratio */
235 static inline uint32_t fsi_smode_lbcrr(int x)
237 return (x & FSI_SMODE_LBCRR_MASK) << FSI_SMODE_LBCRR_SHIFT;
240 /* Encode slave ID */
241 static inline uint32_t fsi_smode_sid(int x)
243 return (x & FSI_SMODE_SID_MASK) << FSI_SMODE_SID_SHIFT;
246 static uint32_t fsi_slave_smode(int id, u8 t_senddly, u8 t_echodly)
248 return FSI_SMODE_WSC | FSI_SMODE_ECRC
250 | fsi_smode_echodly(t_echodly - 1) | fsi_smode_senddly(t_senddly - 1)
251 | fsi_smode_lbcrr(0x8);
254 static int fsi_slave_set_smode(struct fsi_slave *slave)
259 /* set our smode register with the slave ID field to 0; this enables
260 * extended slave addressing
262 smode = fsi_slave_smode(slave->id, slave->t_send_delay, slave->t_echo_delay);
263 data = cpu_to_be32(smode);
265 return fsi_master_write(slave->master, slave->link, slave->id,
266 FSI_SLAVE_BASE + FSI_SMODE,
267 &data, sizeof(data));
270 static int fsi_slave_handle_error(struct fsi_slave *slave, bool write,
271 uint32_t addr, size_t size)
273 struct fsi_master *master = slave->master;
276 uint8_t id, send_delay, echo_delay;
284 dev_dbg(&slave->dev, "handling error on %s to 0x%08x[%zd]",
285 write ? "write" : "read", addr, size);
287 /* try a simple clear of error conditions, which may fail if we've lost
288 * communication with the slave
290 rc = fsi_slave_report_and_clear_errors(slave);
294 /* send a TERM and retry */
296 rc = master->term(master, link, id);
298 rc = fsi_master_read(master, link, id, 0,
301 rc = fsi_slave_report_and_clear_errors(slave);
307 send_delay = slave->t_send_delay;
308 echo_delay = slave->t_echo_delay;
310 /* getting serious, reset the slave via BREAK */
311 rc = fsi_master_break(master, link);
315 slave->t_send_delay = send_delay;
316 slave->t_echo_delay = echo_delay;
318 rc = fsi_slave_set_smode(slave);
322 if (master->link_config)
323 master->link_config(master, link,
325 slave->t_echo_delay);
327 return fsi_slave_report_and_clear_errors(slave);
330 int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
331 void *val, size_t size)
333 uint8_t id = slave->id;
336 rc = fsi_slave_calc_addr(slave, &addr, &id);
340 for (i = 0; i < slave_retries; i++) {
341 rc = fsi_master_read(slave->master, slave->link,
342 id, addr, val, size);
346 err_rc = fsi_slave_handle_error(slave, false, addr, size);
353 EXPORT_SYMBOL_GPL(fsi_slave_read);
355 int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
356 const void *val, size_t size)
358 uint8_t id = slave->id;
361 rc = fsi_slave_calc_addr(slave, &addr, &id);
365 for (i = 0; i < slave_retries; i++) {
366 rc = fsi_master_write(slave->master, slave->link,
367 id, addr, val, size);
371 err_rc = fsi_slave_handle_error(slave, true, addr, size);
378 EXPORT_SYMBOL_GPL(fsi_slave_write);
380 int fsi_slave_claim_range(struct fsi_slave *slave,
381 uint32_t addr, uint32_t size)
383 if (addr + size < addr)
386 if (addr + size > slave->size)
389 /* todo: check for overlapping claims */
392 EXPORT_SYMBOL_GPL(fsi_slave_claim_range);
394 void fsi_slave_release_range(struct fsi_slave *slave,
395 uint32_t addr, uint32_t size)
398 EXPORT_SYMBOL_GPL(fsi_slave_release_range);
400 static bool fsi_device_node_matches(struct device *dev, struct device_node *np,
401 uint32_t addr, uint32_t size)
405 if (of_property_read_reg(np, 0, &paddr, &psize))
413 "node %pOF matches probed address, but not size (got 0x%llx, expected 0x%x)",
420 /* Find a matching node for the slave engine at @address, using @size bytes
421 * of space. Returns NULL if not found, or a matching node with refcount
422 * already incremented.
424 static struct device_node *fsi_device_find_of_node(struct fsi_device *dev)
426 struct device_node *parent, *np;
428 parent = dev_of_node(&dev->slave->dev);
432 for_each_child_of_node(parent, np) {
433 if (fsi_device_node_matches(&dev->dev, np,
434 dev->addr, dev->size))
441 static int fsi_slave_scan(struct fsi_slave *slave)
443 uint32_t engine_addr;
449 * We keep the peek mode and slave engines for the core; so start
450 * at the third slot in the configuration table. We also need to
451 * skip the chip ID entry at the start of the address space.
453 engine_addr = engine_page_size * 3;
454 for (i = 2; i < engine_page_size / sizeof(uint32_t); i++) {
455 uint8_t slots, version, type, crc;
456 struct fsi_device *dev;
460 rc = fsi_slave_read(slave, (i + 1) * sizeof(data),
461 &data, sizeof(data));
463 dev_warn(&slave->dev,
464 "error reading slave registers\n");
467 conf = be32_to_cpu(data);
469 crc = crc4(0, conf, 32);
471 dev_warn(&slave->dev,
472 "crc error in slave register at 0x%04x\n",
477 slots = (conf & FSI_SLAVE_CONF_SLOTS_MASK)
478 >> FSI_SLAVE_CONF_SLOTS_SHIFT;
479 version = (conf & FSI_SLAVE_CONF_VERSION_MASK)
480 >> FSI_SLAVE_CONF_VERSION_SHIFT;
481 type = (conf & FSI_SLAVE_CONF_TYPE_MASK)
482 >> FSI_SLAVE_CONF_TYPE_SHIFT;
485 * Unused address areas are marked by a zero type value; this
486 * skips the defined address areas
488 if (type != 0 && slots != 0) {
491 dev = fsi_create_device(slave);
496 dev->engine_type = type;
497 dev->version = version;
499 dev->addr = engine_addr;
500 dev->size = slots * engine_page_size;
502 trace_fsi_dev_init(dev);
505 "engine[%i]: type %x, version %x, addr %x size %x\n",
506 dev->unit, dev->engine_type, version,
507 dev->addr, dev->size);
509 dev_set_name(&dev->dev, "%02x:%02x:%02x:%02x",
510 slave->master->idx, slave->link,
512 dev->dev.of_node = fsi_device_find_of_node(dev);
514 rc = device_register(&dev->dev);
516 dev_warn(&slave->dev, "add failed: %d\n", rc);
517 put_device(&dev->dev);
521 engine_addr += slots * engine_page_size;
523 if (!(conf & FSI_SLAVE_CONF_NEXT_MASK))
530 static unsigned long aligned_access_size(size_t offset, size_t count)
532 unsigned long offset_unit, count_unit;
536 * 1. Access size must be less than or equal to the maximum access
537 * width or the highest power-of-two factor of offset
538 * 2. Access size must be less than or equal to the amount specified by
541 * The access width is optimal if we can calculate 1 to be strictly
542 * equal while still satisfying 2.
545 /* Find 1 by the bottom bit of offset (with a 4 byte access cap) */
546 offset_unit = BIT(__builtin_ctzl(offset | 4));
548 /* Find 2 by the top bit of count */
549 count_unit = BIT(8 * sizeof(unsigned long) - 1 - __builtin_clzl(count));
551 /* Constrain the maximum access width to the minimum of both criteria */
552 return BIT(__builtin_ctzl(offset_unit | count_unit));
555 static ssize_t fsi_slave_sysfs_raw_read(struct file *file,
556 struct kobject *kobj, struct bin_attribute *attr, char *buf,
557 loff_t off, size_t count)
559 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
560 size_t total_len, read_len;
566 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
569 for (total_len = 0; total_len < count; total_len += read_len) {
570 read_len = aligned_access_size(off, count - total_len);
572 rc = fsi_slave_read(slave, off, buf + total_len, read_len);
582 static ssize_t fsi_slave_sysfs_raw_write(struct file *file,
583 struct kobject *kobj, struct bin_attribute *attr,
584 char *buf, loff_t off, size_t count)
586 struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj));
587 size_t total_len, write_len;
593 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
596 for (total_len = 0; total_len < count; total_len += write_len) {
597 write_len = aligned_access_size(off, count - total_len);
599 rc = fsi_slave_write(slave, off, buf + total_len, write_len);
609 static const struct bin_attribute fsi_slave_raw_attr = {
615 .read = fsi_slave_sysfs_raw_read,
616 .write = fsi_slave_sysfs_raw_write,
619 static void fsi_slave_release(struct device *dev)
621 struct fsi_slave *slave = to_fsi_slave(dev);
623 fsi_free_minor(slave->dev.devt);
624 of_node_put(dev->of_node);
628 static bool fsi_slave_node_matches(struct device_node *np,
629 int link, uint8_t id)
633 if (of_property_read_reg(np, 0, &addr, NULL))
636 return addr == (((u64)link << 32) | id);
639 /* Find a matching node for the slave at (link, id). Returns NULL if none
640 * found, or a matching node with refcount already incremented.
642 static struct device_node *fsi_slave_find_of_node(struct fsi_master *master,
643 int link, uint8_t id)
645 struct device_node *parent, *np;
647 parent = dev_of_node(&master->dev);
651 for_each_child_of_node(parent, np) {
652 if (fsi_slave_node_matches(np, link, id))
659 static ssize_t cfam_read(struct file *filep, char __user *buf, size_t count,
662 struct fsi_slave *slave = filep->private_data;
663 size_t total_len, read_len;
664 loff_t off = *offset;
670 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
673 for (total_len = 0; total_len < count; total_len += read_len) {
676 read_len = min_t(size_t, count, 4);
677 read_len -= off & 0x3;
679 rc = fsi_slave_read(slave, off, &data, read_len);
682 rc = copy_to_user(buf + total_len, &data, read_len);
695 static ssize_t cfam_write(struct file *filep, const char __user *buf,
696 size_t count, loff_t *offset)
698 struct fsi_slave *slave = filep->private_data;
699 size_t total_len, write_len;
700 loff_t off = *offset;
707 if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff)
710 for (total_len = 0; total_len < count; total_len += write_len) {
713 write_len = min_t(size_t, count, 4);
714 write_len -= off & 0x3;
716 rc = copy_from_user(&data, buf + total_len, write_len);
721 rc = fsi_slave_write(slave, off, &data, write_len);
732 static loff_t cfam_llseek(struct file *file, loff_t offset, int whence)
738 file->f_pos = offset;
747 static int cfam_open(struct inode *inode, struct file *file)
749 struct fsi_slave *slave = container_of(inode->i_cdev, struct fsi_slave, cdev);
751 file->private_data = slave;
756 static const struct file_operations cfam_fops = {
757 .owner = THIS_MODULE,
759 .llseek = cfam_llseek,
764 static ssize_t send_term_store(struct device *dev,
765 struct device_attribute *attr,
766 const char *buf, size_t count)
768 struct fsi_slave *slave = to_fsi_slave(dev);
769 struct fsi_master *master = slave->master;
774 master->term(master, slave->link, slave->id);
778 static DEVICE_ATTR_WO(send_term);
780 static ssize_t slave_send_echo_show(struct device *dev,
781 struct device_attribute *attr,
784 struct fsi_slave *slave = to_fsi_slave(dev);
786 return sprintf(buf, "%u\n", slave->t_send_delay);
789 static ssize_t slave_send_echo_store(struct device *dev,
790 struct device_attribute *attr, const char *buf, size_t count)
792 struct fsi_slave *slave = to_fsi_slave(dev);
793 struct fsi_master *master = slave->master;
797 if (kstrtoul(buf, 0, &val) < 0)
800 if (val < 1 || val > 16)
803 if (!master->link_config)
806 /* Current HW mandates that send and echo delay are identical */
807 slave->t_send_delay = val;
808 slave->t_echo_delay = val;
810 rc = fsi_slave_set_smode(slave);
813 if (master->link_config)
814 master->link_config(master, slave->link,
816 slave->t_echo_delay);
821 static DEVICE_ATTR(send_echo_delays, 0600,
822 slave_send_echo_show, slave_send_echo_store);
824 static ssize_t chip_id_show(struct device *dev,
825 struct device_attribute *attr,
828 struct fsi_slave *slave = to_fsi_slave(dev);
830 return sprintf(buf, "%d\n", slave->chip_id);
833 static DEVICE_ATTR_RO(chip_id);
835 static ssize_t cfam_id_show(struct device *dev,
836 struct device_attribute *attr,
839 struct fsi_slave *slave = to_fsi_slave(dev);
841 return sprintf(buf, "0x%x\n", slave->cfam_id);
844 static DEVICE_ATTR_RO(cfam_id);
846 static struct attribute *cfam_attr[] = {
847 &dev_attr_send_echo_delays.attr,
848 &dev_attr_chip_id.attr,
849 &dev_attr_cfam_id.attr,
850 &dev_attr_send_term.attr,
854 static const struct attribute_group cfam_attr_group = {
858 static const struct attribute_group *cfam_attr_groups[] = {
863 static char *cfam_devnode(const struct device *dev, umode_t *mode,
864 kuid_t *uid, kgid_t *gid)
866 const struct fsi_slave *slave = to_fsi_slave(dev);
868 #ifdef CONFIG_FSI_NEW_DEV_NODE
869 return kasprintf(GFP_KERNEL, "fsi/cfam%d", slave->cdev_idx);
871 return kasprintf(GFP_KERNEL, "cfam%d", slave->cdev_idx);
875 static const struct device_type cfam_type = {
877 .devnode = cfam_devnode,
878 .groups = cfam_attr_groups
881 static char *fsi_cdev_devnode(const struct device *dev, umode_t *mode,
882 kuid_t *uid, kgid_t *gid)
884 #ifdef CONFIG_FSI_NEW_DEV_NODE
885 return kasprintf(GFP_KERNEL, "fsi/%s", dev_name(dev));
887 return kasprintf(GFP_KERNEL, "%s", dev_name(dev));
891 const struct device_type fsi_cdev_type = {
893 .devnode = fsi_cdev_devnode,
895 EXPORT_SYMBOL_GPL(fsi_cdev_type);
897 /* Backward compatible /dev/ numbering in "old style" mode */
898 static int fsi_adjust_index(int index)
900 #ifdef CONFIG_FSI_NEW_DEV_NODE
907 static int __fsi_get_new_minor(struct fsi_slave *slave, enum fsi_dev_type type,
908 dev_t *out_dev, int *out_index)
910 int cid = slave->chip_id;
913 /* Check if we qualify for legacy numbering */
914 if (cid >= 0 && cid < 16 && type < 4) {
915 /* Try reserving the legacy number */
916 id = (cid << 4) | type;
917 id = ida_simple_get(&fsi_minor_ida, id, id + 1, GFP_KERNEL);
919 *out_index = fsi_adjust_index(cid);
920 *out_dev = fsi_base_dev + id;
926 /* Fallback to non-legacy allocation */
928 id = ida_simple_get(&fsi_minor_ida, FSI_CHAR_LEGACY_TOP,
929 FSI_CHAR_MAX_DEVICES, GFP_KERNEL);
932 *out_index = fsi_adjust_index(id);
933 *out_dev = fsi_base_dev + id;
937 static const char *const fsi_dev_type_names[] = {
944 int fsi_get_new_minor(struct fsi_device *fdev, enum fsi_dev_type type,
945 dev_t *out_dev, int *out_index)
947 if (fdev->dev.of_node) {
948 int aid = of_alias_get_id(fdev->dev.of_node, fsi_dev_type_names[type]);
951 int id = (aid << 4) | type;
953 id = ida_simple_get(&fsi_minor_ida, id, id + 1, GFP_KERNEL);
956 *out_dev = fsi_base_dev + id;
965 return __fsi_get_new_minor(fdev->slave, type, out_dev, out_index);
967 EXPORT_SYMBOL_GPL(fsi_get_new_minor);
969 void fsi_free_minor(dev_t dev)
971 ida_simple_remove(&fsi_minor_ida, MINOR(dev));
973 EXPORT_SYMBOL_GPL(fsi_free_minor);
975 static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id)
978 struct fsi_slave *slave;
980 __be32 data, llmode, slbus;
983 /* Currently, we only support single slaves on a link, and use the
984 * full 23-bit address range
989 rc = fsi_master_read(master, link, id, 0, &data, sizeof(data));
991 dev_dbg(&master->dev, "can't read slave %02x:%02x %d\n",
995 cfam_id = be32_to_cpu(data);
997 crc = crc4(0, cfam_id, 32);
999 trace_fsi_slave_invalid_cfam(master, link, cfam_id);
1000 dev_warn(&master->dev, "slave %02x:%02x invalid cfam id CRC!\n",
1005 dev_dbg(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n",
1006 cfam_id, master->idx, link, id);
1008 /* If we're behind a master that doesn't provide a self-running bus
1009 * clock, put the slave into async mode
1011 if (master->flags & FSI_MASTER_FLAG_SWCLOCK) {
1012 llmode = cpu_to_be32(FSI_LLMODE_ASYNC);
1013 rc = fsi_master_write(master, link, id,
1014 FSI_SLAVE_BASE + FSI_LLMODE,
1015 &llmode, sizeof(llmode));
1017 dev_warn(&master->dev,
1018 "can't set llmode on slave:%02x:%02x %d\n",
1022 /* We can communicate with a slave; create the slave device and
1025 slave = kzalloc(sizeof(*slave), GFP_KERNEL);
1029 dev_set_name(&slave->dev, "slave@%02x:%02x", link, id);
1030 slave->dev.type = &cfam_type;
1031 slave->dev.parent = &master->dev;
1032 slave->dev.of_node = fsi_slave_find_of_node(master, link, id);
1033 slave->dev.release = fsi_slave_release;
1034 device_initialize(&slave->dev);
1035 slave->cfam_id = cfam_id;
1036 slave->master = master;
1039 slave->size = FSI_SLAVE_SIZE_23b;
1040 slave->t_send_delay = 16;
1041 slave->t_echo_delay = 16;
1043 /* Get chip ID if any */
1044 slave->chip_id = -1;
1045 if (slave->dev.of_node) {
1047 if (!of_property_read_u32(slave->dev.of_node, "chip-id", &prop))
1048 slave->chip_id = prop;
1052 slbus = cpu_to_be32(FSI_SLBUS_FORCE);
1053 rc = fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SLBUS,
1054 &slbus, sizeof(slbus));
1056 dev_warn(&master->dev,
1057 "can't set slbus on slave:%02x:%02x %d\n", link, id,
1060 rc = fsi_slave_set_smode(slave);
1062 dev_warn(&master->dev,
1063 "can't set smode on slave:%02x:%02x %d\n",
1068 /* Allocate a minor in the FSI space */
1069 rc = __fsi_get_new_minor(slave, fsi_dev_cfam, &slave->dev.devt,
1074 trace_fsi_slave_init(slave);
1076 /* Create chardev for userspace access */
1077 cdev_init(&slave->cdev, &cfam_fops);
1078 rc = cdev_device_add(&slave->cdev, &slave->dev);
1080 dev_err(&slave->dev, "Error %d creating slave device\n", rc);
1084 /* Now that we have the cdev registered with the core, any fatal
1085 * failures beyond this point will need to clean up through
1086 * cdev_device_del(). Fortunately though, nothing past here is fatal.
1089 if (master->link_config)
1090 master->link_config(master, link,
1091 slave->t_send_delay,
1092 slave->t_echo_delay);
1094 /* Legacy raw file -> to be removed */
1095 rc = device_create_bin_file(&slave->dev, &fsi_slave_raw_attr);
1097 dev_warn(&slave->dev, "failed to create raw attr: %d\n", rc);
1100 rc = fsi_slave_scan(slave);
1102 dev_dbg(&master->dev, "failed during slave scan with: %d\n",
1108 fsi_free_minor(slave->dev.devt);
1110 of_node_put(slave->dev.of_node);
1115 /* FSI master support */
1116 static int fsi_check_access(uint32_t addr, size_t size)
1121 } else if (size == 2) {
1124 } else if (size != 1)
1130 static int fsi_master_read(struct fsi_master *master, int link,
1131 uint8_t slave_id, uint32_t addr, void *val, size_t size)
1135 trace_fsi_master_read(master, link, slave_id, addr, size);
1137 rc = fsi_check_access(addr, size);
1139 rc = master->read(master, link, slave_id, addr, val, size);
1141 trace_fsi_master_rw_result(master, link, slave_id, addr, size,
1147 static int fsi_master_write(struct fsi_master *master, int link,
1148 uint8_t slave_id, uint32_t addr, const void *val, size_t size)
1152 trace_fsi_master_write(master, link, slave_id, addr, size, val);
1154 rc = fsi_check_access(addr, size);
1156 rc = master->write(master, link, slave_id, addr, val, size);
1158 trace_fsi_master_rw_result(master, link, slave_id, addr, size,
1164 static int fsi_master_link_disable(struct fsi_master *master, int link)
1166 if (master->link_enable)
1167 return master->link_enable(master, link, false);
1172 static int fsi_master_link_enable(struct fsi_master *master, int link)
1174 if (master->link_enable)
1175 return master->link_enable(master, link, true);
1181 * Issue a break command on this link
1183 static int fsi_master_break(struct fsi_master *master, int link)
1187 trace_fsi_master_break(master, link);
1189 if (master->send_break)
1190 rc = master->send_break(master, link);
1191 if (master->link_config)
1192 master->link_config(master, link, 16, 16);
1197 static int fsi_master_scan(struct fsi_master *master)
1201 for (link = 0; link < master->n_links; link++) {
1202 rc = fsi_master_link_enable(master, link);
1204 dev_dbg(&master->dev,
1205 "enable link %d failed: %d\n", link, rc);
1208 rc = fsi_master_break(master, link);
1210 fsi_master_link_disable(master, link);
1211 dev_dbg(&master->dev,
1212 "break to link %d failed: %d\n", link, rc);
1216 rc = fsi_slave_init(master, link, 0);
1218 fsi_master_link_disable(master, link);
1224 static int fsi_slave_remove_device(struct device *dev, void *arg)
1226 device_unregister(dev);
1230 static int fsi_master_remove_slave(struct device *dev, void *arg)
1232 struct fsi_slave *slave = to_fsi_slave(dev);
1234 device_for_each_child(dev, NULL, fsi_slave_remove_device);
1235 cdev_device_del(&slave->cdev, &slave->dev);
1240 static void fsi_master_unscan(struct fsi_master *master)
1242 device_for_each_child(&master->dev, NULL, fsi_master_remove_slave);
1245 int fsi_master_rescan(struct fsi_master *master)
1249 mutex_lock(&master->scan_lock);
1250 fsi_master_unscan(master);
1251 rc = fsi_master_scan(master);
1252 mutex_unlock(&master->scan_lock);
1256 EXPORT_SYMBOL_GPL(fsi_master_rescan);
1258 static ssize_t master_rescan_store(struct device *dev,
1259 struct device_attribute *attr, const char *buf, size_t count)
1261 struct fsi_master *master = to_fsi_master(dev);
1264 rc = fsi_master_rescan(master);
1271 static DEVICE_ATTR(rescan, 0200, NULL, master_rescan_store);
1273 static ssize_t master_break_store(struct device *dev,
1274 struct device_attribute *attr, const char *buf, size_t count)
1276 struct fsi_master *master = to_fsi_master(dev);
1278 fsi_master_break(master, 0);
1283 static DEVICE_ATTR(break, 0200, NULL, master_break_store);
1285 static struct attribute *master_attrs[] = {
1286 &dev_attr_break.attr,
1287 &dev_attr_rescan.attr,
1291 ATTRIBUTE_GROUPS(master);
1293 static struct class fsi_master_class = {
1294 .name = "fsi-master",
1295 .dev_groups = master_groups,
1298 int fsi_master_register(struct fsi_master *master)
1301 struct device_node *np;
1303 mutex_init(&master->scan_lock);
1304 master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL);
1305 if (master->idx < 0)
1308 dev_set_name(&master->dev, "fsi%d", master->idx);
1309 master->dev.class = &fsi_master_class;
1311 rc = device_register(&master->dev);
1313 ida_simple_remove(&master_ida, master->idx);
1317 np = dev_of_node(&master->dev);
1318 if (!of_property_read_bool(np, "no-scan-on-init")) {
1319 mutex_lock(&master->scan_lock);
1320 fsi_master_scan(master);
1321 mutex_unlock(&master->scan_lock);
1326 EXPORT_SYMBOL_GPL(fsi_master_register);
1328 void fsi_master_unregister(struct fsi_master *master)
1330 if (master->idx >= 0) {
1331 ida_simple_remove(&master_ida, master->idx);
1335 mutex_lock(&master->scan_lock);
1336 fsi_master_unscan(master);
1337 mutex_unlock(&master->scan_lock);
1338 device_unregister(&master->dev);
1340 EXPORT_SYMBOL_GPL(fsi_master_unregister);
1342 /* FSI core & Linux bus type definitions */
1344 static int fsi_bus_match(struct device *dev, struct device_driver *drv)
1346 struct fsi_device *fsi_dev = to_fsi_dev(dev);
1347 struct fsi_driver *fsi_drv = to_fsi_drv(drv);
1348 const struct fsi_device_id *id;
1350 if (!fsi_drv->id_table)
1353 for (id = fsi_drv->id_table; id->engine_type; id++) {
1354 if (id->engine_type != fsi_dev->engine_type)
1356 if (id->version == FSI_VERSION_ANY ||
1357 id->version == fsi_dev->version)
1364 int fsi_driver_register(struct fsi_driver *fsi_drv)
1368 if (!fsi_drv->id_table)
1371 return driver_register(&fsi_drv->drv);
1373 EXPORT_SYMBOL_GPL(fsi_driver_register);
1375 void fsi_driver_unregister(struct fsi_driver *fsi_drv)
1377 driver_unregister(&fsi_drv->drv);
1379 EXPORT_SYMBOL_GPL(fsi_driver_unregister);
1381 struct bus_type fsi_bus_type = {
1383 .match = fsi_bus_match,
1385 EXPORT_SYMBOL_GPL(fsi_bus_type);
1387 static int __init fsi_init(void)
1391 rc = alloc_chrdev_region(&fsi_base_dev, 0, FSI_CHAR_MAX_DEVICES, "fsi");
1394 rc = bus_register(&fsi_bus_type);
1398 rc = class_register(&fsi_master_class);
1405 bus_unregister(&fsi_bus_type);
1407 unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES);
1410 postcore_initcall(fsi_init);
1412 static void fsi_exit(void)
1414 class_unregister(&fsi_master_class);
1415 bus_unregister(&fsi_bus_type);
1416 unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES);
1417 ida_destroy(&fsi_minor_ida);
1419 module_exit(fsi_exit);
1420 module_param(discard_errors, int, 0664);
1421 MODULE_LICENSE("GPL");
1422 MODULE_PARM_DESC(discard_errors, "Don't invoke error handling on bus accesses");