On Fri, Feb 02, 2024 at 01:05:12AM +0100, Michael Grzeschik wrote:
> Add the newly introduced 9pfs transport gadget interface with an new
> multi composed gadget together with acm and eem.
>
> When using this legacy module, it is also possible to
> mount the 9PFS usb dir as root filesystem. Just follow the
> instrucitons from Documentation/filesystems/9p.rst
Why are we adding new "legacy" gadgets? What's wrong with the "correct"
api instead? You need a lot of justification here to add something to
an api we want to one day just delete.
And can you wrap your changelog at 72 columns?
>
> Signed-off-by: Michael Grzeschik <m.grzeschik@xxxxxxxxxxxxxx>
>
> ---
> v1 -> v2:
> - deleted the usbg 9pfs detailed instruction from commit message
> - added depends on net for NET_9P dependency
> ---
> drivers/usb/gadget/legacy/9pfs.c | 268 +++++++++++++++++++++++++++++++++++++
> drivers/usb/gadget/legacy/Kconfig | 16 +++
> drivers/usb/gadget/legacy/Makefile | 2 +
> 3 files changed, 286 insertions(+)
>
> diff --git a/drivers/usb/gadget/legacy/9pfs.c b/drivers/usb/gadget/legacy/9pfs.c
> new file mode 100644
> index 0000000000000..3ac7f2e92c5a3
> --- /dev/null
> +++ b/drivers/usb/gadget/legacy/9pfs.c
> @@ -0,0 +1,268 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * usb9pfs.c -- Gadget usb9pfs
> + *
> + * Copyright (C) 2023 Michael Grzeschik
> + */
> +
> +/*
> + * Gadget usb9pfs only needs two bulk endpoints, and will use the usb9pfs usb
> + * transport to mount host filesystem via usb gadget. This driver will
> + * also add one ACM and NCM interface.
Why "also"? What are those interfaces going to be used for and what do
they have to do with 9pfs?
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/slab.h>
> +#include <linux/device.h>
> +#include <linux/module.h>
> +#include <linux/err.h>
> +#include <linux/usb/composite.h>
> +#include <linux/netdevice.h>
> +
> +#include "u_eem.h"
> +#include "u_ether.h"
> +
> +/*-------------------------------------------------------------------------*/
> +USB_GADGET_COMPOSITE_OPTIONS();
> +
> +USB_ETHERNET_MODULE_PARAMETERS();
> +
> +/* Defines */
> +
> +#define DRIVER_VERSION_STR "v1.0"
> +#define DRIVER_VERSION_NUM 0x1000
> +
> +#define DRIVER_DESC "Composite Gadget (9P + ACM + NCM)"
> +
> +/*-------------------------------------------------------------------------*/
> +
> +#define DRIVER_VENDOR_NUM 0x1d6b /* Linux Foundation */
> +#define DRIVER_PRODUCT_NUM 0x0109 /* Linux-USB 9PFS Gadget */
> +
> +/*-------------------------------------------------------------------------*/
> +
> +static struct usb_device_descriptor device_desc = {
> + .bLength = sizeof(device_desc),
> + .bDescriptorType = USB_DT_DEVICE,
> +
> + /* .bcdUSB = DYNAMIC */
> +
> + .bDeviceClass = USB_CLASS_MISC,
> + .bDeviceSubClass = 2,
> + .bDeviceProtocol = 1,
> +
> + /* .bMaxPacketSize0 = f(hardware) */
> +
> + /* Vendor and product id can be overridden by module parameters. */
> + .idVendor = cpu_to_le16(DRIVER_VENDOR_NUM),
> + .idProduct = cpu_to_le16(DRIVER_PRODUCT_NUM),
> + /* .bcdDevice = f(hardware) */
> + /* .iManufacturer = DYNAMIC */
> + /* .iProduct = DYNAMIC */
> + /* NO SERIAL NUMBER */
> + /*.bNumConfigurations = DYNAMIC*/
> +};
> +
> +static const struct usb_descriptor_header *otg_desc[2];
> +
> +static struct usb_string strings_dev[] = {
> + [USB_GADGET_MANUFACTURER_IDX].s = "",
> + [USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
> + [USB_GADGET_SERIAL_IDX].s = "",
> + { } /* end of list */
> +};
> +
> +static struct usb_gadget_strings stringtab_dev = {
> + .language = 0x0409, /* en-us */
> + .strings = strings_dev,
> +};
> +
> +static struct usb_gadget_strings *dev_strings[] = {
> + &stringtab_dev,
> + NULL,
> +};
> +
> +static struct usb_configuration cdc_driver_conf = {
> + .label = DRIVER_DESC,
> + .bConfigurationValue = 1,
> + /* .iConfiguration = DYNAMIC */
> + .bmAttributes = USB_CONFIG_ATT_SELFPOWER,
> +};
> +
> +static struct usb_function *f_9pfs;
> +static struct usb_function_instance *fi_9pfs;
> +
> +static struct usb_function *f_acm;
> +static struct usb_function_instance *fi_acm;
> +
> +static struct usb_function *f_eem;
> +static struct usb_function_instance *fi_eem;
> +
> +static int cdc_do_config(struct usb_configuration *c)
> +{
> + int ret;
> +
> + if (gadget_is_otg(c->cdev->gadget)) {
> + c->descriptors = otg_desc;
> + c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
> + }
> +
> + f_9pfs = usb_get_function(fi_9pfs);
> + if (IS_ERR(f_9pfs))
> + return PTR_ERR(f_9pfs);
> +
> + ret = usb_add_function(c, f_9pfs);
> + if (ret < 0)
> + goto err_func_9pfs;
> +
> + f_acm = usb_get_function(fi_acm);
> + if (IS_ERR(f_acm)) {
> + ret = PTR_ERR(f_acm);
> + goto err_func_acm;
> + }
> +
> + ret = usb_add_function(c, f_acm);
> + if (ret)
> + goto err_conf;
> +
> + f_eem = usb_get_function(fi_eem);
> + if (IS_ERR(f_eem)) {
> + ret = PTR_ERR(f_eem);
> + goto err_eem;
> + }
> +
> + ret = usb_add_function(c, f_eem);
> + if (ret)
> + goto err_run;
> +
> + return 0;
> +err_run:
> + usb_put_function(f_eem);
> +err_eem:
> + usb_remove_function(c, f_acm);
> +err_conf:
> + usb_put_function(f_acm);
> +err_func_acm:
> + usb_remove_function(c, f_9pfs);
> +err_func_9pfs:
> + usb_put_function(f_9pfs);
> + return ret;
> +}
> +
> +static int usb9pfs_bind(struct usb_composite_dev *cdev)
> +{
> + struct f_eem_opts *eem_opts = NULL;
> + int status;
> +
> + fi_9pfs = usb_get_function_instance("usb9pfs");
> + if (IS_ERR(fi_9pfs)) {
> + if (PTR_ERR(fi_9pfs) == -ENOENT)
> + return -EPROBE_DEFER;
> + return PTR_ERR(fi_9pfs);
> + }
> +
> + /* set up serial link layer */
> + fi_acm = usb_get_function_instance("acm");
> + if (IS_ERR(fi_acm)) {
> + if (PTR_ERR(fi_9pfs) == -ENOENT)
> + return -EPROBE_DEFER;
> + status = PTR_ERR(fi_acm);
> + goto err_conf_acm;
> + }
> +
> + fi_eem = usb_get_function_instance("eem");
> + if (IS_ERR(fi_eem)) {
> + if (PTR_ERR(fi_9pfs) == -ENOENT)
> + return -EPROBE_DEFER;
> + status = PTR_ERR(fi_eem);
> + goto err_conf_eem;
> + }
> +
> + eem_opts = container_of(fi_eem, struct f_eem_opts, func_inst);
> +
> + gether_set_qmult(eem_opts->net, qmult);
> + if (!gether_set_host_addr(eem_opts->net, host_addr))
> + pr_info("using host ethernet address: %s", host_addr);
> + if (!gether_set_dev_addr(eem_opts->net, dev_addr))
> + pr_info("using self ethernet address: %s", dev_addr);
> +
> + /* Allocate string descriptor numbers ... note that string
> + * contents can be overridden by the composite_dev glue.
> + */
> + status = usb_string_ids_tab(cdev, strings_dev);
> + if (status < 0)
> + return status;
> +
> + device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
> + device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
> + device_desc.iSerialNumber = strings_dev[USB_GADGET_SERIAL_IDX].id;
> +
> + /* support OTG systems */
> + if (gadget_is_otg(cdev->gadget)) {
> + if (!otg_desc[0]) {
> + struct usb_descriptor_header *usb_desc;
> +
> + usb_desc = usb_otg_descriptor_alloc(cdev->gadget);
> + if (!usb_desc) {
> + status = -ENOMEM;
> + goto err_conf_otg;
> + }
> + usb_otg_descriptor_init(cdev->gadget, usb_desc);
> + otg_desc[0] = usb_desc;
> + otg_desc[1] = NULL;
> + }
> + }
> +
> + status = usb_add_config(cdev, &cdc_driver_conf, cdc_do_config);
> + if (status)
> + goto err_free_otg_desc;
> +
> + usb_ep_autoconfig_reset(cdev->gadget);
> + usb_composite_overwrite_options(cdev, &coverwrite);
> +
> + dev_info(&cdev->gadget->dev, DRIVER_DESC " version: " DRIVER_VERSION_STR "\n");
When drivers are working properly, they are quiet.
thanks,
greg k-h
