// SPDX-License-Identifier: GPL-2.0-only /* * FSI core driver * * Copyright (C) IBM Corporation 2016 * * TODO: * - Rework topology * - s/chip_id/chip_loc * - s/cfam/chip (cfam_id -> chip_id etc...) */ #include #include #include #include #include #include #include #include #include #include #include #include "fsi-master.h" #define CREATE_TRACE_POINTS #include #define FSI_SLAVE_CONF_NEXT_MASK GENMASK(31, 31) #define FSI_SLAVE_CONF_SLOTS_MASK GENMASK(23, 16) #define FSI_SLAVE_CONF_SLOTS_SHIFT 16 #define FSI_SLAVE_CONF_VERSION_MASK GENMASK(15, 12) #define FSI_SLAVE_CONF_VERSION_SHIFT 12 #define FSI_SLAVE_CONF_TYPE_MASK GENMASK(11, 4) #define FSI_SLAVE_CONF_TYPE_SHIFT 4 #define FSI_SLAVE_CONF_CRC_SHIFT 4 #define FSI_SLAVE_CONF_CRC_MASK GENMASK(3, 0) #define FSI_SLAVE_CONF_DATA_BITS 28 #define FSI_PEEK_BASE 0x410 static const int engine_page_size = 0x400; #define FSI_SLAVE_BASE 0x800 /* * FSI slave engine control register offsets */ #define FSI_SMODE 0x0 /* R/W: Mode register */ #define FSI_SISC 0x8 /* R/W: Interrupt condition */ #define FSI_SSTAT 0x14 /* R : Slave status */ #define FSI_LLMODE 0x100 /* R/W: Link layer mode register */ /* * SMODE fields */ #define FSI_SMODE_WSC 0x80000000 /* Warm start done */ #define FSI_SMODE_ECRC 0x20000000 /* Hw CRC check */ #define FSI_SMODE_SID_SHIFT 24 /* ID shift */ #define FSI_SMODE_SID_MASK 3 /* ID Mask */ #define FSI_SMODE_ED_SHIFT 20 /* Echo delay shift */ #define FSI_SMODE_ED_MASK 0xf /* Echo delay mask */ #define FSI_SMODE_SD_SHIFT 16 /* Send delay shift */ #define FSI_SMODE_SD_MASK 0xf /* Send delay mask */ #define FSI_SMODE_LBCRR_SHIFT 8 /* Clk ratio shift */ #define FSI_SMODE_LBCRR_MASK 0xf /* Clk ratio mask */ /* * LLMODE fields */ #define FSI_LLMODE_ASYNC 0x1 #define FSI_SLAVE_SIZE_23b 0x800000 static DEFINE_IDA(master_ida); struct fsi_slave { struct device dev; struct fsi_master *master; struct cdev cdev; int cdev_idx; int id; /* FSI address */ int link; /* FSI link# */ u32 cfam_id; int chip_id; uint32_t size; /* size of slave address space */ u8 t_send_delay; u8 t_echo_delay; }; #define to_fsi_master(d) container_of(d, struct fsi_master, dev) #define to_fsi_slave(d) container_of(d, struct fsi_slave, dev) static const int slave_retries = 2; static int discard_errors; static dev_t fsi_base_dev; static DEFINE_IDA(fsi_minor_ida); #define FSI_CHAR_MAX_DEVICES 0x1000 /* Legacy /dev numbering: 4 devices per chip, 16 chips */ #define FSI_CHAR_LEGACY_TOP 64 static int fsi_master_read(struct fsi_master *master, int link, uint8_t slave_id, uint32_t addr, void *val, size_t size); static int fsi_master_write(struct fsi_master *master, int link, uint8_t slave_id, uint32_t addr, const void *val, size_t size); static int fsi_master_break(struct fsi_master *master, int link); /* * fsi_device_read() / fsi_device_write() / fsi_device_peek() * * FSI endpoint-device support * * Read / write / peek accessors for a client * * Parameters: * dev: Structure passed to FSI client device drivers on probe(). * addr: FSI address of given device. Client should pass in its base address * plus desired offset to access its register space. * val: For read/peek this is the value read at the specified address. For * write this is value to write to the specified address. * The data in val must be FSI bus endian (big endian). * size: Size in bytes of the operation. Sizes supported are 1, 2 and 4 bytes. * Addresses must be aligned on size boundaries or an error will result. */ int fsi_device_read(struct fsi_device *dev, uint32_t addr, void *val, size_t size) { if (addr > dev->size || size > dev->size || addr > dev->size - size) return -EINVAL; return fsi_slave_read(dev->slave, dev->addr + addr, val, size); } EXPORT_SYMBOL_GPL(fsi_device_read); int fsi_device_write(struct fsi_device *dev, uint32_t addr, const void *val, size_t size) { if (addr > dev->size || size > dev->size || addr > dev->size - size) return -EINVAL; return fsi_slave_write(dev->slave, dev->addr + addr, val, size); } EXPORT_SYMBOL_GPL(fsi_device_write); int fsi_device_peek(struct fsi_device *dev, void *val) { uint32_t addr = FSI_PEEK_BASE + ((dev->unit - 2) * sizeof(uint32_t)); return fsi_slave_read(dev->slave, addr, val, sizeof(uint32_t)); } static void fsi_device_release(struct device *_device) { struct fsi_device *device = to_fsi_dev(_device); of_node_put(device->dev.of_node); kfree(device); } static struct fsi_device *fsi_create_device(struct fsi_slave *slave) { struct fsi_device *dev; dev = kzalloc(sizeof(*dev), GFP_KERNEL); if (!dev) return NULL; dev->dev.parent = &slave->dev; dev->dev.bus = &fsi_bus_type; dev->dev.release = fsi_device_release; return dev; } /* FSI slave support */ static int fsi_slave_calc_addr(struct fsi_slave *slave, uint32_t *addrp, uint8_t *idp) { uint32_t addr = *addrp; uint8_t id = *idp; if (addr > slave->size) return -EINVAL; /* For 23 bit addressing, we encode the extra two bits in the slave * id (and the slave's actual ID needs to be 0). */ if (addr > 0x1fffff) { if (slave->id != 0) return -EINVAL; id = (addr >> 21) & 0x3; addr &= 0x1fffff; } *addrp = addr; *idp = id; return 0; } static int fsi_slave_report_and_clear_errors(struct fsi_slave *slave) { struct fsi_master *master = slave->master; __be32 irq, stat; int rc, link; uint8_t id; link = slave->link; id = slave->id; rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SISC, &irq, sizeof(irq)); if (rc) return rc; rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SSTAT, &stat, sizeof(stat)); if (rc) return rc; dev_dbg(&slave->dev, "status: 0x%08x, sisc: 0x%08x\n", be32_to_cpu(stat), be32_to_cpu(irq)); /* clear interrupts */ return fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SISC, &irq, sizeof(irq)); } /* Encode slave local bus echo delay */ static inline uint32_t fsi_smode_echodly(int x) { return (x & FSI_SMODE_ED_MASK) << FSI_SMODE_ED_SHIFT; } /* Encode slave local bus send delay */ static inline uint32_t fsi_smode_senddly(int x) { return (x & FSI_SMODE_SD_MASK) << FSI_SMODE_SD_SHIFT; } /* Encode slave local bus clock rate ratio */ static inline uint32_t fsi_smode_lbcrr(int x) { return (x & FSI_SMODE_LBCRR_MASK) << FSI_SMODE_LBCRR_SHIFT; } /* Encode slave ID */ static inline uint32_t fsi_smode_sid(int x) { return (x & FSI_SMODE_SID_MASK) << FSI_SMODE_SID_SHIFT; } static uint32_t fsi_slave_smode(int id, u8 t_senddly, u8 t_echodly) { return FSI_SMODE_WSC | FSI_SMODE_ECRC | fsi_smode_sid(id) | fsi_smode_echodly(t_echodly - 1) | fsi_smode_senddly(t_senddly - 1) | fsi_smode_lbcrr(0x8); } static int fsi_slave_set_smode(struct fsi_slave *slave) { uint32_t smode; __be32 data; /* set our smode register with the slave ID field to 0; this enables * extended slave addressing */ smode = fsi_slave_smode(slave->id, slave->t_send_delay, slave->t_echo_delay); data = cpu_to_be32(smode); return fsi_master_write(slave->master, slave->link, slave->id, FSI_SLAVE_BASE + FSI_SMODE, &data, sizeof(data)); } static int fsi_slave_handle_error(struct fsi_slave *slave, bool write, uint32_t addr, size_t size) { struct fsi_master *master = slave->master; int rc, link; uint32_t reg; uint8_t id, send_delay, echo_delay; if (discard_errors) return -1; link = slave->link; id = slave->id; dev_dbg(&slave->dev, "handling error on %s to 0x%08x[%zd]", write ? "write" : "read", addr, size); /* try a simple clear of error conditions, which may fail if we've lost * communication with the slave */ rc = fsi_slave_report_and_clear_errors(slave); if (!rc) return 0; /* send a TERM and retry */ if (master->term) { rc = master->term(master, link, id); if (!rc) { rc = fsi_master_read(master, link, id, 0, ®, sizeof(reg)); if (!rc) rc = fsi_slave_report_and_clear_errors(slave); if (!rc) return 0; } } send_delay = slave->t_send_delay; echo_delay = slave->t_echo_delay; /* getting serious, reset the slave via BREAK */ rc = fsi_master_break(master, link); if (rc) return rc; slave->t_send_delay = send_delay; slave->t_echo_delay = echo_delay; rc = fsi_slave_set_smode(slave); if (rc) return rc; if (master->link_config) master->link_config(master, link, slave->t_send_delay, slave->t_echo_delay); return fsi_slave_report_and_clear_errors(slave); } int fsi_slave_read(struct fsi_slave *slave, uint32_t addr, void *val, size_t size) { uint8_t id = slave->id; int rc, err_rc, i; rc = fsi_slave_calc_addr(slave, &addr, &id); if (rc) return rc; for (i = 0; i < slave_retries; i++) { rc = fsi_master_read(slave->master, slave->link, id, addr, val, size); if (!rc) break; err_rc = fsi_slave_handle_error(slave, false, addr, size); if (err_rc) break; } return rc; } EXPORT_SYMBOL_GPL(fsi_slave_read); int fsi_slave_write(struct fsi_slave *slave, uint32_t addr, const void *val, size_t size) { uint8_t id = slave->id; int rc, err_rc, i; rc = fsi_slave_calc_addr(slave, &addr, &id); if (rc) return rc; for (i = 0; i < slave_retries; i++) { rc = fsi_master_write(slave->master, slave->link, id, addr, val, size); if (!rc) break; err_rc = fsi_slave_handle_error(slave, true, addr, size); if (err_rc) break; } return rc; } EXPORT_SYMBOL_GPL(fsi_slave_write); extern int fsi_slave_claim_range(struct fsi_slave *slave, uint32_t addr, uint32_t size) { if (addr + size < addr) return -EINVAL; if (addr + size > slave->size) return -EINVAL; /* todo: check for overlapping claims */ return 0; } EXPORT_SYMBOL_GPL(fsi_slave_claim_range); extern void fsi_slave_release_range(struct fsi_slave *slave, uint32_t addr, uint32_t size) { } EXPORT_SYMBOL_GPL(fsi_slave_release_range); static bool fsi_device_node_matches(struct device *dev, struct device_node *np, uint32_t addr, uint32_t size) { unsigned int len, na, ns; const __be32 *prop; uint32_t psize; na = of_n_addr_cells(np); ns = of_n_size_cells(np); if (na != 1 || ns != 1) return false; prop = of_get_property(np, "reg", &len); if (!prop || len != 8) return false; if (of_read_number(prop, 1) != addr) return false; psize = of_read_number(prop + 1, 1); if (psize != size) { dev_warn(dev, "node %s matches probed address, but not size (got 0x%x, expected 0x%x)", of_node_full_name(np), psize, size); } return true; } /* Find a matching node for the slave engine at @address, using @size bytes * of space. Returns NULL if not found, or a matching node with refcount * already incremented. */ static struct device_node *fsi_device_find_of_node(struct fsi_device *dev) { struct device_node *parent, *np; parent = dev_of_node(&dev->slave->dev); if (!parent) return NULL; for_each_child_of_node(parent, np) { if (fsi_device_node_matches(&dev->dev, np, dev->addr, dev->size)) return np; } return NULL; } static int fsi_slave_scan(struct fsi_slave *slave) { uint32_t engine_addr; int rc, i; /* * scan engines * * We keep the peek mode and slave engines for the core; so start * at the third slot in the configuration table. We also need to * skip the chip ID entry at the start of the address space. */ engine_addr = engine_page_size * 3; for (i = 2; i < engine_page_size / sizeof(uint32_t); i++) { uint8_t slots, version, type, crc; struct fsi_device *dev; uint32_t conf; __be32 data; rc = fsi_slave_read(slave, (i + 1) * sizeof(data), &data, sizeof(data)); if (rc) { dev_warn(&slave->dev, "error reading slave registers\n"); return -1; } conf = be32_to_cpu(data); crc = crc4(0, conf, 32); if (crc) { dev_warn(&slave->dev, "crc error in slave register at 0x%04x\n", i); return -1; } slots = (conf & FSI_SLAVE_CONF_SLOTS_MASK) >> FSI_SLAVE_CONF_SLOTS_SHIFT; version = (conf & FSI_SLAVE_CONF_VERSION_MASK) >> FSI_SLAVE_CONF_VERSION_SHIFT; type = (conf & FSI_SLAVE_CONF_TYPE_MASK) >> FSI_SLAVE_CONF_TYPE_SHIFT; /* * Unused address areas are marked by a zero type value; this * skips the defined address areas */ if (type != 0 && slots != 0) { /* create device */ dev = fsi_create_device(slave); if (!dev) return -ENOMEM; dev->slave = slave; dev->engine_type = type; dev->version = version; dev->unit = i; dev->addr = engine_addr; dev->size = slots * engine_page_size; dev_dbg(&slave->dev, "engine[%i]: type %x, version %x, addr %x size %x\n", dev->unit, dev->engine_type, version, dev->addr, dev->size); dev_set_name(&dev->dev, "%02x:%02x:%02x:%02x", slave->master->idx, slave->link, slave->id, i - 2); dev->dev.of_node = fsi_device_find_of_node(dev); rc = device_register(&dev->dev); if (rc) { dev_warn(&slave->dev, "add failed: %d\n", rc); put_device(&dev->dev); } } engine_addr += slots * engine_page_size; if (!(conf & FSI_SLAVE_CONF_NEXT_MASK)) break; } return 0; } static unsigned long aligned_access_size(size_t offset, size_t count) { unsigned long offset_unit, count_unit; /* Criteria: * * 1. Access size must be less than or equal to the maximum access * width or the highest power-of-two factor of offset * 2. Access size must be less than or equal to the amount specified by * count * * The access width is optimal if we can calculate 1 to be strictly * equal while still satisfying 2. */ /* Find 1 by the bottom bit of offset (with a 4 byte access cap) */ offset_unit = BIT(__builtin_ctzl(offset | 4)); /* Find 2 by the top bit of count */ count_unit = BIT(8 * sizeof(unsigned long) - 1 - __builtin_clzl(count)); /* Constrain the maximum access width to the minimum of both criteria */ return BIT(__builtin_ctzl(offset_unit | count_unit)); } static ssize_t fsi_slave_sysfs_raw_read(struct file *file, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); size_t total_len, read_len; int rc; if (off < 0) return -EINVAL; if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) return -EINVAL; for (total_len = 0; total_len < count; total_len += read_len) { read_len = aligned_access_size(off, count - total_len); rc = fsi_slave_read(slave, off, buf + total_len, read_len); if (rc) return rc; off += read_len; } return count; } static ssize_t fsi_slave_sysfs_raw_write(struct file *file, struct kobject *kobj, struct bin_attribute *attr, char *buf, loff_t off, size_t count) { struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); size_t total_len, write_len; int rc; if (off < 0) return -EINVAL; if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) return -EINVAL; for (total_len = 0; total_len < count; total_len += write_len) { write_len = aligned_access_size(off, count - total_len); rc = fsi_slave_write(slave, off, buf + total_len, write_len); if (rc) return rc; off += write_len; } return count; } static const struct bin_attribute fsi_slave_raw_attr = { .attr = { .name = "raw", .mode = 0600, }, .size = 0, .read = fsi_slave_sysfs_raw_read, .write = fsi_slave_sysfs_raw_write, }; static void fsi_slave_release(struct device *dev) { struct fsi_slave *slave = to_fsi_slave(dev); fsi_free_minor(slave->dev.devt); of_node_put(dev->of_node); kfree(slave); } static bool fsi_slave_node_matches(struct device_node *np, int link, uint8_t id) { unsigned int len, na, ns; const __be32 *prop; na = of_n_addr_cells(np); ns = of_n_size_cells(np); /* Ensure we have the correct format for addresses and sizes in * reg properties */ if (na != 2 || ns != 0) return false; prop = of_get_property(np, "reg", &len); if (!prop || len != 8) return false; return (of_read_number(prop, 1) == link) && (of_read_number(prop + 1, 1) == id); } /* Find a matching node for the slave at (link, id). Returns NULL if none * found, or a matching node with refcount already incremented. */ static struct device_node *fsi_slave_find_of_node(struct fsi_master *master, int link, uint8_t id) { struct device_node *parent, *np; parent = dev_of_node(&master->dev); if (!parent) return NULL; for_each_child_of_node(parent, np) { if (fsi_slave_node_matches(np, link, id)) return np; } return NULL; } static ssize_t cfam_read(struct file *filep, char __user *buf, size_t count, loff_t *offset) { struct fsi_slave *slave = filep->private_data; size_t total_len, read_len; loff_t off = *offset; ssize_t rc; if (off < 0) return -EINVAL; if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) return -EINVAL; for (total_len = 0; total_len < count; total_len += read_len) { __be32 data; read_len = min_t(size_t, count, 4); read_len -= off & 0x3; rc = fsi_slave_read(slave, off, &data, read_len); if (rc) goto fail; rc = copy_to_user(buf + total_len, &data, read_len); if (rc) { rc = -EFAULT; goto fail; } off += read_len; } rc = count; fail: *offset = off; return count; } static ssize_t cfam_write(struct file *filep, const char __user *buf, size_t count, loff_t *offset) { struct fsi_slave *slave = filep->private_data; size_t total_len, write_len; loff_t off = *offset; ssize_t rc; if (off < 0) return -EINVAL; if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) return -EINVAL; for (total_len = 0; total_len < count; total_len += write_len) { __be32 data; write_len = min_t(size_t, count, 4); write_len -= off & 0x3; rc = copy_from_user(&data, buf + total_len, write_len); if (rc) { rc = -EFAULT; goto fail; } rc = fsi_slave_write(slave, off, &data, write_len); if (rc) goto fail; off += write_len; } rc = count; fail: *offset = off; return count; } static loff_t cfam_llseek(struct file *file, loff_t offset, int whence) { switch (whence) { case SEEK_CUR: break; case SEEK_SET: file->f_pos = offset; break; default: return -EINVAL; } return offset; } static int cfam_open(struct inode *inode, struct file *file) { struct fsi_slave *slave = container_of(inode->i_cdev, struct fsi_slave, cdev); file->private_data = slave; return 0; } static const struct file_operations cfam_fops = { .owner = THIS_MODULE, .open = cfam_open, .llseek = cfam_llseek, .read = cfam_read, .write = cfam_write, }; static ssize_t send_term_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct fsi_slave *slave = to_fsi_slave(dev); struct fsi_master *master = slave->master; if (!master->term) return -ENODEV; master->term(master, slave->link, slave->id); return count; } static DEVICE_ATTR_WO(send_term); static ssize_t slave_send_echo_show(struct device *dev, struct device_attribute *attr, char *buf) { struct fsi_slave *slave = to_fsi_slave(dev); return sprintf(buf, "%u\n", slave->t_send_delay); } static ssize_t slave_send_echo_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct fsi_slave *slave = to_fsi_slave(dev); struct fsi_master *master = slave->master; unsigned long val; int rc; if (kstrtoul(buf, 0, &val) < 0) return -EINVAL; if (val < 1 || val > 16) return -EINVAL; if (!master->link_config) return -ENXIO; /* Current HW mandates that send and echo delay are identical */ slave->t_send_delay = val; slave->t_echo_delay = val; rc = fsi_slave_set_smode(slave); if (rc < 0) return rc; if (master->link_config) master->link_config(master, slave->link, slave->t_send_delay, slave->t_echo_delay); return count; } static DEVICE_ATTR(send_echo_delays, 0600, slave_send_echo_show, slave_send_echo_store); static ssize_t chip_id_show(struct device *dev, struct device_attribute *attr, char *buf) { struct fsi_slave *slave = to_fsi_slave(dev); return sprintf(buf, "%d\n", slave->chip_id); } static DEVICE_ATTR_RO(chip_id); static ssize_t cfam_id_show(struct device *dev, struct device_attribute *attr, char *buf) { struct fsi_slave *slave = to_fsi_slave(dev); return sprintf(buf, "0x%x\n", slave->cfam_id); } static DEVICE_ATTR_RO(cfam_id); static struct attribute *cfam_attr[] = { &dev_attr_send_echo_delays.attr, &dev_attr_chip_id.attr, &dev_attr_cfam_id.attr, &dev_attr_send_term.attr, NULL, }; static const struct attribute_group cfam_attr_group = { .attrs = cfam_attr, }; static const struct attribute_group *cfam_attr_groups[] = { &cfam_attr_group, NULL, }; static char *cfam_devnode(struct device *dev, umode_t *mode, kuid_t *uid, kgid_t *gid) { struct fsi_slave *slave = to_fsi_slave(dev); #ifdef CONFIG_FSI_NEW_DEV_NODE return kasprintf(GFP_KERNEL, "fsi/cfam%d", slave->cdev_idx); #else return kasprintf(GFP_KERNEL, "cfam%d", slave->cdev_idx); #endif } static const struct device_type cfam_type = { .name = "cfam", .devnode = cfam_devnode, .groups = cfam_attr_groups }; static char *fsi_cdev_devnode(struct device *dev, umode_t *mode, kuid_t *uid, kgid_t *gid) { #ifdef CONFIG_FSI_NEW_DEV_NODE return kasprintf(GFP_KERNEL, "fsi/%s", dev_name(dev)); #else return kasprintf(GFP_KERNEL, "%s", dev_name(dev)); #endif } const struct device_type fsi_cdev_type = { .name = "fsi-cdev", .devnode = fsi_cdev_devnode, }; EXPORT_SYMBOL_GPL(fsi_cdev_type); /* Backward compatible /dev/ numbering in "old style" mode */ static int fsi_adjust_index(int index) { #ifdef CONFIG_FSI_NEW_DEV_NODE return index; #else return index + 1; #endif } static int __fsi_get_new_minor(struct fsi_slave *slave, enum fsi_dev_type type, dev_t *out_dev, int *out_index) { int cid = slave->chip_id; int id; /* Check if we qualify for legacy numbering */ if (cid >= 0 && cid < 16 && type < 4) { /* Try reserving the legacy number */ id = (cid << 4) | type; id = ida_simple_get(&fsi_minor_ida, id, id + 1, GFP_KERNEL); if (id >= 0) { *out_index = fsi_adjust_index(cid); *out_dev = fsi_base_dev + id; return 0; } /* Other failure */ if (id != -ENOSPC) return id; /* Fallback to non-legacy allocation */ } id = ida_simple_get(&fsi_minor_ida, FSI_CHAR_LEGACY_TOP, FSI_CHAR_MAX_DEVICES, GFP_KERNEL); if (id < 0) return id; *out_index = fsi_adjust_index(id); *out_dev = fsi_base_dev + id; return 0; } int fsi_get_new_minor(struct fsi_device *fdev, enum fsi_dev_type type, dev_t *out_dev, int *out_index) { return __fsi_get_new_minor(fdev->slave, type, out_dev, out_index); } EXPORT_SYMBOL_GPL(fsi_get_new_minor); void fsi_free_minor(dev_t dev) { ida_simple_remove(&fsi_minor_ida, MINOR(dev)); } EXPORT_SYMBOL_GPL(fsi_free_minor); static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id) { uint32_t cfam_id; struct fsi_slave *slave; uint8_t crc; __be32 data, llmode; int rc; /* Currently, we only support single slaves on a link, and use the * full 23-bit address range */ if (id != 0) return -EINVAL; rc = fsi_master_read(master, link, id, 0, &data, sizeof(data)); if (rc) { dev_dbg(&master->dev, "can't read slave %02x:%02x %d\n", link, id, rc); return -ENODEV; } cfam_id = be32_to_cpu(data); crc = crc4(0, cfam_id, 32); if (crc) { dev_warn(&master->dev, "slave %02x:%02x invalid cfam id CRC!\n", link, id); return -EIO; } dev_dbg(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n", cfam_id, master->idx, link, id); /* If we're behind a master that doesn't provide a self-running bus * clock, put the slave into async mode */ if (master->flags & FSI_MASTER_FLAG_SWCLOCK) { llmode = cpu_to_be32(FSI_LLMODE_ASYNC); rc = fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_LLMODE, &llmode, sizeof(llmode)); if (rc) dev_warn(&master->dev, "can't set llmode on slave:%02x:%02x %d\n", link, id, rc); } /* We can communicate with a slave; create the slave device and * register. */ slave = kzalloc(sizeof(*slave), GFP_KERNEL); if (!slave) return -ENOMEM; dev_set_name(&slave->dev, "slave@%02x:%02x", link, id); slave->dev.type = &cfam_type; slave->dev.parent = &master->dev; slave->dev.of_node = fsi_slave_find_of_node(master, link, id); slave->dev.release = fsi_slave_release; device_initialize(&slave->dev); slave->cfam_id = cfam_id; slave->master = master; slave->link = link; slave->id = id; slave->size = FSI_SLAVE_SIZE_23b; slave->t_send_delay = 16; slave->t_echo_delay = 16; /* Get chip ID if any */ slave->chip_id = -1; if (slave->dev.of_node) { uint32_t prop; if (!of_property_read_u32(slave->dev.of_node, "chip-id", &prop)) slave->chip_id = prop; } rc = fsi_slave_set_smode(slave); if (rc) { dev_warn(&master->dev, "can't set smode on slave:%02x:%02x %d\n", link, id, rc); goto err_free; } /* Allocate a minor in the FSI space */ rc = __fsi_get_new_minor(slave, fsi_dev_cfam, &slave->dev.devt, &slave->cdev_idx); if (rc) goto err_free; /* Create chardev for userspace access */ cdev_init(&slave->cdev, &cfam_fops); rc = cdev_device_add(&slave->cdev, &slave->dev); if (rc) { dev_err(&slave->dev, "Error %d creating slave device\n", rc); goto err_free_ida; } /* Now that we have the cdev registered with the core, any fatal * failures beyond this point will need to clean up through * cdev_device_del(). Fortunately though, nothing past here is fatal. */ if (master->link_config) master->link_config(master, link, slave->t_send_delay, slave->t_echo_delay); /* Legacy raw file -> to be removed */ rc = device_create_bin_file(&slave->dev, &fsi_slave_raw_attr); if (rc) dev_warn(&slave->dev, "failed to create raw attr: %d\n", rc); rc = fsi_slave_scan(slave); if (rc) dev_dbg(&master->dev, "failed during slave scan with: %d\n", rc); return 0; err_free_ida: fsi_free_minor(slave->dev.devt); err_free: of_node_put(slave->dev.of_node); kfree(slave); return rc; } /* FSI master support */ static int fsi_check_access(uint32_t addr, size_t size) { if (size == 4) { if (addr & 0x3) return -EINVAL; } else if (size == 2) { if (addr & 0x1) return -EINVAL; } else if (size != 1) return -EINVAL; return 0; } static int fsi_master_read(struct fsi_master *master, int link, uint8_t slave_id, uint32_t addr, void *val, size_t size) { int rc; trace_fsi_master_read(master, link, slave_id, addr, size); rc = fsi_check_access(addr, size); if (!rc) rc = master->read(master, link, slave_id, addr, val, size); trace_fsi_master_rw_result(master, link, slave_id, addr, size, false, val, rc); return rc; } static int fsi_master_write(struct fsi_master *master, int link, uint8_t slave_id, uint32_t addr, const void *val, size_t size) { int rc; trace_fsi_master_write(master, link, slave_id, addr, size, val); rc = fsi_check_access(addr, size); if (!rc) rc = master->write(master, link, slave_id, addr, val, size); trace_fsi_master_rw_result(master, link, slave_id, addr, size, true, val, rc); return rc; } static int fsi_master_link_enable(struct fsi_master *master, int link) { if (master->link_enable) return master->link_enable(master, link); return 0; } /* * Issue a break command on this link */ static int fsi_master_break(struct fsi_master *master, int link) { int rc = 0; trace_fsi_master_break(master, link); if (master->send_break) rc = master->send_break(master, link); if (master->link_config) master->link_config(master, link, 16, 16); return rc; } static int fsi_master_scan(struct fsi_master *master) { int link, rc; for (link = 0; link < master->n_links; link++) { rc = fsi_master_link_enable(master, link); if (rc) { dev_dbg(&master->dev, "enable link %d failed: %d\n", link, rc); continue; } rc = fsi_master_break(master, link); if (rc) { dev_dbg(&master->dev, "break to link %d failed: %d\n", link, rc); continue; } fsi_slave_init(master, link, 0); } return 0; } static int fsi_slave_remove_device(struct device *dev, void *arg) { device_unregister(dev); return 0; } static int fsi_master_remove_slave(struct device *dev, void *arg) { struct fsi_slave *slave = to_fsi_slave(dev); device_for_each_child(dev, NULL, fsi_slave_remove_device); cdev_device_del(&slave->cdev, &slave->dev); put_device(dev); return 0; } static void fsi_master_unscan(struct fsi_master *master) { device_for_each_child(&master->dev, NULL, fsi_master_remove_slave); } int fsi_master_rescan(struct fsi_master *master) { int rc; mutex_lock(&master->scan_lock); fsi_master_unscan(master); rc = fsi_master_scan(master); mutex_unlock(&master->scan_lock); return rc; } EXPORT_SYMBOL_GPL(fsi_master_rescan); static ssize_t master_rescan_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct fsi_master *master = to_fsi_master(dev); int rc; rc = fsi_master_rescan(master); if (rc < 0) return rc; return count; } static DEVICE_ATTR(rescan, 0200, NULL, master_rescan_store); static ssize_t master_break_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct fsi_master *master = to_fsi_master(dev); fsi_master_break(master, 0); return count; } static DEVICE_ATTR(break, 0200, NULL, master_break_store); static struct attribute *master_attrs[] = { &dev_attr_break.attr, &dev_attr_rescan.attr, NULL }; ATTRIBUTE_GROUPS(master); static struct class fsi_master_class = { .name = "fsi-master", .dev_groups = master_groups, }; int fsi_master_register(struct fsi_master *master) { int rc; struct device_node *np; mutex_init(&master->scan_lock); master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL); dev_set_name(&master->dev, "fsi%d", master->idx); master->dev.class = &fsi_master_class; rc = device_register(&master->dev); if (rc) { ida_simple_remove(&master_ida, master->idx); return rc; } np = dev_of_node(&master->dev); if (!of_property_read_bool(np, "no-scan-on-init")) { mutex_lock(&master->scan_lock); fsi_master_scan(master); mutex_unlock(&master->scan_lock); } return 0; } EXPORT_SYMBOL_GPL(fsi_master_register); void fsi_master_unregister(struct fsi_master *master) { if (master->idx >= 0) { ida_simple_remove(&master_ida, master->idx); master->idx = -1; } mutex_lock(&master->scan_lock); fsi_master_unscan(master); mutex_unlock(&master->scan_lock); device_unregister(&master->dev); } EXPORT_SYMBOL_GPL(fsi_master_unregister); /* FSI core & Linux bus type definitions */ static int fsi_bus_match(struct device *dev, struct device_driver *drv) { struct fsi_device *fsi_dev = to_fsi_dev(dev); struct fsi_driver *fsi_drv = to_fsi_drv(drv); const struct fsi_device_id *id; if (!fsi_drv->id_table) return 0; for (id = fsi_drv->id_table; id->engine_type; id++) { if (id->engine_type != fsi_dev->engine_type) continue; if (id->version == FSI_VERSION_ANY || id->version == fsi_dev->version) return 1; } return 0; } int fsi_driver_register(struct fsi_driver *fsi_drv) { if (!fsi_drv) return -EINVAL; if (!fsi_drv->id_table) return -EINVAL; return driver_register(&fsi_drv->drv); } EXPORT_SYMBOL_GPL(fsi_driver_register); void fsi_driver_unregister(struct fsi_driver *fsi_drv) { driver_unregister(&fsi_drv->drv); } EXPORT_SYMBOL_GPL(fsi_driver_unregister); struct bus_type fsi_bus_type = { .name = "fsi", .match = fsi_bus_match, }; EXPORT_SYMBOL_GPL(fsi_bus_type); static int __init fsi_init(void) { int rc; rc = alloc_chrdev_region(&fsi_base_dev, 0, FSI_CHAR_MAX_DEVICES, "fsi"); if (rc) return rc; rc = bus_register(&fsi_bus_type); if (rc) goto fail_bus; rc = class_register(&fsi_master_class); if (rc) goto fail_class; return 0; fail_class: bus_unregister(&fsi_bus_type); fail_bus: unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES); return rc; } postcore_initcall(fsi_init); static void fsi_exit(void) { class_unregister(&fsi_master_class); bus_unregister(&fsi_bus_type); unregister_chrdev_region(fsi_base_dev, FSI_CHAR_MAX_DEVICES); ida_destroy(&fsi_minor_ida); } module_exit(fsi_exit); module_param(discard_errors, int, 0664); MODULE_LICENSE("GPL"); MODULE_PARM_DESC(discard_errors, "Don't invoke error handling on bus accesses");