hd.c
// SPDX-License-Identifier: GPL-2.0
/*
* Greybus Host Device
*
* Copyright 2014-2015 Google Inc.
* Copyright 2014-2015 Linaro Ltd.
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/greybus.h>
#include "greybus_trace.h"
EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_create);
EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_release);
EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_add);
EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_del);
EXPORT_TRACEPOINT_SYMBOL_GPL(gb_hd_in);
EXPORT_TRACEPOINT_SYMBOL_GPL(gb_message_submit);
static struct ida gb_hd_bus_id_map;
int gb_hd_output(struct gb_host_device *hd, void *req, u16 size, u8 cmd,
bool async)
{
if (!hd || !hd->driver || !hd->driver->output)
return -EINVAL;
return hd->driver->output(hd, req, size, cmd, async);
}
EXPORT_SYMBOL_GPL(gb_hd_output);
static ssize_t bus_id_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gb_host_device *hd = to_gb_host_device(dev);
return sprintf(buf, "%d\n", hd->bus_id);
}
static DEVICE_ATTR_RO(bus_id);
static struct attribute *bus_attrs[] = {
&dev_attr_bus_id.attr,
NULL
};
ATTRIBUTE_GROUPS(bus);
int gb_hd_cport_reserve(struct gb_host_device *hd, u16 cport_id)
{
struct ida *id_map = &hd->cport_id_map;
int ret;
ret = ida_simple_get(id_map, cport_id, cport_id + 1, GFP_KERNEL);
if (ret < 0) {
dev_err(&hd->dev, "failed to reserve cport %u\n", cport_id);
return ret;
}
return 0;
}
EXPORT_SYMBOL_GPL(gb_hd_cport_reserve);
void gb_hd_cport_release_reserved(struct gb_host_device *hd, u16 cport_id)
{
struct ida *id_map = &hd->cport_id_map;
ida_simple_remove(id_map, cport_id);
}
EXPORT_SYMBOL_GPL(gb_hd_cport_release_reserved);
/* Locking: Caller guarantees serialisation */
int gb_hd_cport_allocate(struct gb_host_device *hd, int cport_id,
unsigned long flags)
{
struct ida *id_map = &hd->cport_id_map;
int ida_start, ida_end;
if (hd->driver->cport_allocate)
return hd->driver->cport_allocate(hd, cport_id, flags);
if (cport_id < 0) {
ida_start = 0;
ida_end = hd->num_cports;
} else if (cport_id < hd->num_cports) {
ida_start = cport_id;
ida_end = cport_id + 1;
} else {
dev_err(&hd->dev, "cport %d not available\n", cport_id);
return -EINVAL;
}
return ida_simple_get(id_map, ida_start, ida_end, GFP_KERNEL);
}
/* Locking: Caller guarantees serialisation */
void gb_hd_cport_release(struct gb_host_device *hd, u16 cport_id)
{
if (hd->driver->cport_release) {
hd->driver->cport_release(hd, cport_id);
return;
}
ida_simple_remove(&hd->cport_id_map, cport_id);
}
static void gb_hd_release(struct device *dev)
{
struct gb_host_device *hd = to_gb_host_device(dev);
trace_gb_hd_release(hd);
if (hd->svc)
gb_svc_put(hd->svc);
ida_simple_remove(&gb_hd_bus_id_map, hd->bus_id);
ida_destroy(&hd->cport_id_map);
kfree(hd);
}
struct device_type greybus_hd_type = {
.name = "greybus_host_device",
.release = gb_hd_release,
};
struct gb_host_device *gb_hd_create(struct gb_hd_driver *driver,
struct device *parent,
size_t buffer_size_max,
size_t num_cports)
{
struct gb_host_device *hd;
int ret;
/*
* Validate that the driver implements all of the callbacks
* so that we don't have to every time we make them.
*/
if ((!driver->message_send) || (!driver->message_cancel)) {
dev_err(parent, "mandatory hd-callbacks missing\n");
return ERR_PTR(-EINVAL);
}
if (buffer_size_max < GB_OPERATION_MESSAGE_SIZE_MIN) {
dev_err(parent, "greybus host-device buffers too small\n");
return ERR_PTR(-EINVAL);
}
if (num_cports == 0 || num_cports > CPORT_ID_MAX + 1) {
dev_err(parent, "Invalid number of CPorts: %zu\n", num_cports);
return ERR_PTR(-EINVAL);
}
/*
* Make sure to never allocate messages larger than what the Greybus
* protocol supports.
*/
if (buffer_size_max > GB_OPERATION_MESSAGE_SIZE_MAX) {
dev_warn(parent, "limiting buffer size to %u\n",
GB_OPERATION_MESSAGE_SIZE_MAX);
buffer_size_max = GB_OPERATION_MESSAGE_SIZE_MAX;
}
hd = kzalloc(sizeof(*hd) + driver->hd_priv_size, GFP_KERNEL);
if (!hd)
return ERR_PTR(-ENOMEM);
ret = ida_simple_get(&gb_hd_bus_id_map, 1, 0, GFP_KERNEL);
if (ret < 0) {
kfree(hd);
return ERR_PTR(ret);
}
hd->bus_id = ret;
hd->driver = driver;
INIT_LIST_HEAD(&hd->modules);
INIT_LIST_HEAD(&hd->connections);
ida_init(&hd->cport_id_map);
hd->buffer_size_max = buffer_size_max;
hd->num_cports = num_cports;
hd->dev.parent = parent;
hd->dev.bus = &greybus_bus_type;
hd->dev.type = &greybus_hd_type;
hd->dev.groups = bus_groups;
hd->dev.dma_mask = hd->dev.parent->dma_mask;
device_initialize(&hd->dev);
dev_set_name(&hd->dev, "greybus%d", hd->bus_id);
trace_gb_hd_create(hd);
hd->svc = gb_svc_create(hd);
if (!hd->svc) {
dev_err(&hd->dev, "failed to create svc\n");
put_device(&hd->dev);
return ERR_PTR(-ENOMEM);
}
return hd;
}
EXPORT_SYMBOL_GPL(gb_hd_create);
int gb_hd_add(struct gb_host_device *hd)
{
int ret;
ret = device_add(&hd->dev);
if (ret)
return ret;
ret = gb_svc_add(hd->svc);
if (ret) {
device_del(&hd->dev);
return ret;
}
trace_gb_hd_add(hd);
return 0;
}
EXPORT_SYMBOL_GPL(gb_hd_add);
void gb_hd_del(struct gb_host_device *hd)
{
trace_gb_hd_del(hd);
/*
* Tear down the svc and flush any on-going hotplug processing before
* removing the remaining interfaces.
*/
gb_svc_del(hd->svc);
device_del(&hd->dev);
}
EXPORT_SYMBOL_GPL(gb_hd_del);
void gb_hd_shutdown(struct gb_host_device *hd)
{
gb_svc_del(hd->svc);
}
EXPORT_SYMBOL_GPL(gb_hd_shutdown);
void gb_hd_put(struct gb_host_device *hd)
{
put_device(&hd->dev);
}
EXPORT_SYMBOL_GPL(gb_hd_put);
int __init gb_hd_init(void)
{
ida_init(&gb_hd_bus_id_map);
return 0;
}
void gb_hd_exit(void)
{
ida_destroy(&gb_hd_bus_id_map);
}