// 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/of_address.h>
#include <linux/of_device.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"
#include "fsi-slave.h"
#define CREATE_TRACE_POINTS
#include <trace/events/fsi.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);
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)
{
u64 paddr, psize;
if (of_property_read_reg(np, 0, &paddr, &psize))
return false;
if (paddr != addr)
return false;
if (psize != size) {
dev_warn(dev,
"node %pOF matches probed address, but not size (got 0x%llx, expected 0x%x)",
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)
{
u64 addr;
if (of_property_read_reg(np, 0, &addr, NULL))
return false;
return addr == (((u64)link << 32) | 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, which has 0 - 0x3f reserved
* in the ida range. cid goes up to 0xf and type contains two
* bits, so construct the id with the below two bit shift.
*/
id = (cid << 2) | type;
id = ida_alloc_range(&fsi_minor_ida, id, id, 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_alloc_range(&fsi_minor_ida, FSI_CHAR_LEGACY_TOP,
FSI_CHAR_MAX_DEVICES - 1, GFP_KERNEL);
if (id < 0)
return id;
*out_index = fsi_adjust_index(id);
*out_dev = fsi_base_dev + id;
return 0;
}
static const char *const fsi_dev_type_names[] = {
"cfam",
"sbefifo",
"scom",
"occ",
};
int fsi_get_new_minor(struct fsi_device *fdev, enum fsi_dev_type type,
dev_t *out_dev, int *out_index)
{
if (fdev->dev.of_node) {
int aid = of_alias_get_id(fdev->dev.of_node, fsi_dev_type_names[type]);
if (aid >= 0) {
/* Use the same scheme as the legacy numbers. */
int id = (aid << 2) | type;
id = ida_alloc_range(&fsi_minor_ida, id, id, GFP_KERNEL);
if (id >= 0) {
*out_index = aid;
*out_dev = fsi_base_dev + id;
return 0;
}
if (id != -ENOSPC)
return id;
}
}
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_free(&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;
trace_fsi_master_scan(master, true);
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)
{
trace_fsi_master_scan(master, false);
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);
/* Alloc the requested index if it's non-zero */
if (master->idx) {
master->idx = ida_alloc_range(&master_ida, master->idx,
master->idx, GFP_KERNEL);
} else {
master->idx = ida_alloc(&master_ida, GFP_KERNEL);
}
if (master->idx < 0)
return master->idx;
if (!dev_name(&master->dev))
dev_set_name(&master->dev, "fsi%d", master->idx);
master->dev.class = &fsi_master_class;
mutex_lock(&master->scan_lock);
rc = device_register(&master->dev);
if (rc) {
ida_free(&master_ida, master->idx);
goto out;
}
np = dev_of_node(&master->dev);
if (!of_property_read_bool(np, "no-scan-on-init")) {
fsi_master_scan(master);
}
out:
mutex_unlock(&master->scan_lock);
return rc;
}
EXPORT_SYMBOL_GPL(fsi_master_register);
void fsi_master_unregister(struct fsi_master *master)
{
int idx = master->idx;
trace_fsi_master_unregister(master);
mutex_lock(&master->scan_lock);
fsi_master_unscan(master);
master->n_links = 0;
mutex_unlock(&master->scan_lock);
device_unregister(&master->dev);
ida_free(&master_ida, idx);
}
EXPORT_SYMBOL_GPL(fsi_master_unregister);
/* FSI core & Linux bus type definitions */
static int fsi_bus_match(struct device *dev, const struct device_driver *drv)
{
struct fsi_device *fsi_dev = to_fsi_dev(dev);
const 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) {
if (drv->of_match_table) {
if (of_driver_match_device(dev, drv))
return 1;
} else {
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_DESCRIPTION("FSI core driver");
MODULE_LICENSE("GPL");
MODULE_PARM_DESC(discard_errors, "Don't invoke error handling on bus accesses");
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