diff options
Diffstat (limited to 'drivers/greybus/hd.c')
| -rw-r--r-- | drivers/greybus/hd.c | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/drivers/greybus/hd.c b/drivers/greybus/hd.c new file mode 100644 index 000000000..72b21bf2d --- /dev/null +++ b/drivers/greybus/hd.c @@ -0,0 +1,256 @@ +// 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); +} |