| // 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 <linux/crc4.h> |
| #include <linux/device.h> |
| #include <linux/fsi.h> |
| #include <linux/idr.h> |
| #include <linux/module.h> |
| #include <linux/of.h> |
| #include <linux/slab.h> |
| #include <linux/bitops.h> |
| #include <linux/cdev.h> |
| #include <linux/fs.h> |
| #include <linux/uaccess.h> |
| |
| #include "fsi-master.h" |
| |
| #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_SLBUS 0x30 /* W : LBUS Ownership */ |
| #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 */ |
| |
| /* |
| * SLBUS fields |
| */ |
| #define FSI_SLBUS_FORCE 0x80000000 /* Force LBUS ownership */ |
| |
| /* |
| * 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 CREATE_TRACE_POINTS |
| #include <trace/events/fsi.h> |
| |
| #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); |
| |
| 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); |
| |
| 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; |
| |
| trace_fsi_dev_init(dev); |
| |
| 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 rc; |
| } |
| |
| 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 rc; |
| } |
| |
| 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(const struct device *dev, umode_t *mode, |
| kuid_t *uid, kgid_t *gid) |
| { |
| const 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(const 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, slbus; |
| 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) { |
| trace_fsi_slave_invalid_cfam(master, link, cfam_id); |
| 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; |
| |
| } |
| |
| slbus = cpu_to_be32(FSI_SLBUS_FORCE); |
| rc = fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SLBUS, |
| &slbus, sizeof(slbus)); |
| if (rc) |
| dev_warn(&master->dev, |
| "can't set slbus on slave:%02x:%02x %d\n", link, id, |
| rc); |
| |
| 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; |
| |
| trace_fsi_slave_init(slave); |
| |
| /* 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_disable(struct fsi_master *master, int link) |
| { |
| if (master->link_enable) |
| return master->link_enable(master, link, false); |
| |
| return 0; |
| } |
| |
| static int fsi_master_link_enable(struct fsi_master *master, int link) |
| { |
| if (master->link_enable) |
| return master->link_enable(master, link, true); |
| |
| 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) { |
| fsi_master_link_disable(master, link); |
| dev_dbg(&master->dev, |
| "break to link %d failed: %d\n", link, rc); |
| continue; |
| } |
| |
| rc = fsi_slave_init(master, link, 0); |
| if (rc) |
| fsi_master_link_disable(master, link); |
| } |
| |
| 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); |
| if (master->idx < 0) |
| return master->idx; |
| |
| 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"); |