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alistair23-linux/drivers/staging/greybus/hd.c

164 lines
3.4 KiB
C

/*
* Greybus Host Device
*
* Copyright 2014-2015 Google Inc.
* Copyright 2014-2015 Linaro Ltd.
*
* Released under the GPLv2 only.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/slab.h>
#include "greybus.h"
static struct ida gb_hd_bus_id_map;
static void gb_hd_release(struct device *dev)
{
struct gb_host_device *hd = to_gb_host_device(dev);
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)) {
pr_err("Must implement all gb_hd_driver callbacks!\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->interfaces);
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.dma_mask = hd->dev.parent->dma_mask;
device_initialize(&hd->dev);
dev_set_name(&hd->dev, "greybus%d", hd->bus_id);
return hd;
}
EXPORT_SYMBOL_GPL(gb_hd_create);
static int gb_hd_create_svc_connection(struct gb_host_device *hd)
{
hd->svc_connection = gb_connection_create_static(hd, GB_SVC_CPORT_ID,
GREYBUS_PROTOCOL_SVC);
if (!hd->svc_connection) {
dev_err(&hd->dev, "failed to create svc connection\n");
return -ENOMEM;
}
return 0;
}
int gb_hd_add(struct gb_host_device *hd)
{
int ret;
ret = device_add(&hd->dev);
if (ret)
return ret;
ret = gb_hd_create_svc_connection(hd);
if (ret) {
device_del(&hd->dev);
return ret;
}
ret = gb_connection_init(hd->svc_connection);
if (ret) {
gb_connection_destroy(hd->svc_connection);
device_del(&hd->dev);
return ret;
}
return 0;
}
EXPORT_SYMBOL_GPL(gb_hd_add);
void gb_hd_del(struct gb_host_device *hd)
{
gb_interfaces_remove(hd);
gb_connection_destroy(hd->svc_connection);
device_del(&hd->dev);
}
EXPORT_SYMBOL_GPL(gb_hd_del);
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);
}