linux/drivers/fsi/fsi-core.c
Eddie James 196964a31c fsi: core: Set slave local bus ownership during init
The driver ought to claim local bus ownership of the slave it's
communicating with.

This is for multi-master setups. The slave (in theory) will deny access
to masters who try to access the CFAM address space but who don't "own"
the bus.

As driver doesn't seem to perform any other teardown there is no need to
"un-claim" ownership at teardown. Also I'm not aware of any multi-master
setup using this driver so it shouldn't actually matter. Also, the
hardware doesn't seem to enforce this despite being required in the
specification...

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
2020-09-10 12:22:49 +09:30

1427 lines
33 KiB
C

// 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 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);
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,
&reg, 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, 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) {
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;
/* 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);
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");