From 2f550553e23c889b54440bf05e2484d84105e48d Mon Sep 17 00:00:00 2001 From: Hardik Gajjar Date: Fri, 1 Mar 2024 13:47:08 +0100 Subject: [PATCH] usb: gadget: f_fs: Add the missing get_alt callback The Apple CarLife iAP gadget has a descriptor in userspace with two alternate settings. The host sends the set_alt request to configure alt_setting 0 or 1, and this is verified by the subsequent get_alt request. This patch implements and sets the get_alt callback. Without the get_alt callback, composite.c abruptly concludes the USB_REQ_GET/SET_INTERFACE request, assuming only one alt setting for the endpoint. unlike the uvc and ncm, f_fs gadget is fully implemented in userspace, and driver just reset the eps and generate the event. so no additional adaptaion associated with this change is not required in set_alt callback Signed-off-by: Hardik Gajjar Link: https://lore.kernel.org/r/20240301124708.120394-1-hgajjar@de.adit-jv.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/f_fs.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c index bffbc1dc651f9..d3a7f7bae07b0 100644 --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -45,6 +45,7 @@ #include "configfs.h" #define FUNCTIONFS_MAGIC 0xa647361 /* Chosen by a honest dice roll ;) */ +#define MAX_ALT_SETTINGS 2 /* Allow up to 2 alt settings to be set. */ MODULE_IMPORT_NS(DMA_BUF); @@ -80,6 +81,7 @@ struct ffs_function { short *interfaces_nums; struct usb_function function; + int cur_alt[MAX_CONFIG_INTERFACES]; }; @@ -103,6 +105,7 @@ static int __must_check ffs_func_eps_enable(struct ffs_function *func); static int ffs_func_bind(struct usb_configuration *, struct usb_function *); static int ffs_func_set_alt(struct usb_function *, unsigned, unsigned); +static int ffs_func_get_alt(struct usb_function *f, unsigned int intf); static void ffs_func_disable(struct usb_function *); static int ffs_func_setup(struct usb_function *, const struct usb_ctrlrequest *); @@ -3704,6 +3707,15 @@ static void ffs_reset_work(struct work_struct *work) ffs_data_reset(ffs); } +static int ffs_func_get_alt(struct usb_function *f, + unsigned int interface) +{ + struct ffs_function *func = ffs_func_from_usb(f); + int intf = ffs_func_revmap_intf(func, interface); + + return (intf < 0) ? intf : func->cur_alt[interface]; +} + static int ffs_func_set_alt(struct usb_function *f, unsigned interface, unsigned alt) { @@ -3711,6 +3723,9 @@ static int ffs_func_set_alt(struct usb_function *f, struct ffs_data *ffs = func->ffs; int ret = 0, intf; + if (alt > MAX_ALT_SETTINGS) + return -EINVAL; + if (alt != (unsigned)-1) { intf = ffs_func_revmap_intf(func, interface); if (intf < 0) @@ -3738,8 +3753,10 @@ static int ffs_func_set_alt(struct usb_function *f, ffs->func = func; ret = ffs_func_eps_enable(func); - if (ret >= 0) + if (ret >= 0) { ffs_event_add(ffs, FUNCTIONFS_ENABLE); + func->cur_alt[interface] = alt; + } return ret; } @@ -4066,6 +4083,7 @@ static struct usb_function *ffs_alloc(struct usb_function_instance *fi) func->function.bind = ffs_func_bind; func->function.unbind = ffs_func_unbind; func->function.set_alt = ffs_func_set_alt; + func->function.get_alt = ffs_func_get_alt; func->function.disable = ffs_func_disable; func->function.setup = ffs_func_setup; func->function.req_match = ffs_func_req_match;