From 6f1de344557315a8e5de0d15a28276198ca7fdac Mon Sep 17 00:00:00 2001 From: Andrzej Pietrasiewicz Date: Thu, 16 Oct 2014 13:33:31 +0200 Subject: [PATCH] usb: gadget: f_midi: add configfs support Make the midi function available for gadgets composed with configfs. Signed-off-by: Andrzej Pietrasiewicz Signed-off-by: Felipe Balbi --- .../ABI/testing/configfs-usb-gadget-midi | 12 ++ drivers/usb/gadget/Kconfig | 14 ++ drivers/usb/gadget/function/f_midi.c | 161 +++++++++++++++++- drivers/usb/gadget/function/u_midi.h | 8 + 4 files changed, 193 insertions(+), 2 deletions(-) create mode 100644 Documentation/ABI/testing/configfs-usb-gadget-midi diff --git a/Documentation/ABI/testing/configfs-usb-gadget-midi b/Documentation/ABI/testing/configfs-usb-gadget-midi new file mode 100644 index 000000000000..6b341df7249c --- /dev/null +++ b/Documentation/ABI/testing/configfs-usb-gadget-midi @@ -0,0 +1,12 @@ +What: /config/usb-gadget/gadget/functions/midi.name +Date: Nov 2014 +KernelVersion: 3.19 +Description: + The attributes: + + index - index value for the USB MIDI adapter + id - ID string for the USB MIDI adapter + buflen - MIDI buffer length + qlen - USB read request queue length + in_ports - number of MIDI input ports + out_ports - number of MIDI output ports diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig index b51307805151..501c2a38d071 100644 --- a/drivers/usb/gadget/Kconfig +++ b/drivers/usb/gadget/Kconfig @@ -396,6 +396,20 @@ config USB_CONFIGFS_F_UAC2 received from the USB Host and choose to provide whatever it wants as audio data to the USB Host. +config USB_CONFIGFS_F_MIDI + boolean "MIDI function" + depends on USB_CONFIGFS + depends on SND + select USB_LIBCOMPOSITE + select SND_RAWMIDI + select USB_F_MIDI + help + The MIDI Function acts as a USB Audio device, with one MIDI + input and one MIDI output. These MIDI jacks appear as + a sound "card" in the ALSA sound system. Other MIDI + connections can then be made on the gadget system, using + ALSA's aconnect utility etc. + source "drivers/usb/gadget/legacy/Kconfig" endchoice diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c index ec2a9cee4589..1f94dad57307 100644 --- a/drivers/usb/gadget/function/f_midi.c +++ b/drivers/usb/gadget/function/f_midi.c @@ -896,12 +896,145 @@ static int f_midi_bind(struct usb_configuration *c, struct usb_function *f) return status; } +static inline struct f_midi_opts *to_f_midi_opts(struct config_item *item) +{ + return container_of(to_config_group(item), struct f_midi_opts, + func_inst.group); +} + +CONFIGFS_ATTR_STRUCT(f_midi_opts); +CONFIGFS_ATTR_OPS(f_midi_opts); + +static void midi_attr_release(struct config_item *item) +{ + struct f_midi_opts *opts = to_f_midi_opts(item); + + usb_put_function_instance(&opts->func_inst); +} + +static struct configfs_item_operations midi_item_ops = { + .release = midi_attr_release, + .show_attribute = f_midi_opts_attr_show, + .store_attribute = f_midi_opts_attr_store, +}; + +#define F_MIDI_OPT(name, test_limit, limit) \ +static ssize_t f_midi_opts_##name##_show(struct f_midi_opts *opts, char *page) \ +{ \ + int result; \ + \ + mutex_lock(&opts->lock); \ + result = sprintf(page, "%d\n", opts->name); \ + mutex_unlock(&opts->lock); \ + \ + return result; \ +} \ + \ +static ssize_t f_midi_opts_##name##_store(struct f_midi_opts *opts, \ + const char *page, size_t len) \ +{ \ + int ret; \ + u32 num; \ + \ + mutex_lock(&opts->lock); \ + if (opts->refcnt) { \ + ret = -EBUSY; \ + goto end; \ + } \ + \ + ret = kstrtou32(page, 0, &num); \ + if (ret) \ + goto end; \ + \ + if (test_limit && num > limit) { \ + ret = -EINVAL; \ + goto end; \ + } \ + opts->name = num; \ + ret = len; \ + \ +end: \ + mutex_unlock(&opts->lock); \ + return ret; \ +} \ + \ +static struct f_midi_opts_attribute f_midi_opts_##name = \ + __CONFIGFS_ATTR(name, S_IRUGO | S_IWUSR, f_midi_opts_##name##_show, \ + f_midi_opts_##name##_store) + +F_MIDI_OPT(index, true, SNDRV_CARDS); +F_MIDI_OPT(buflen, false, 0); +F_MIDI_OPT(qlen, false, 0); +F_MIDI_OPT(in_ports, true, MAX_PORTS); +F_MIDI_OPT(out_ports, true, MAX_PORTS); + +static ssize_t f_midi_opts_id_show(struct f_midi_opts *opts, char *page) +{ + int result; + + mutex_lock(&opts->lock); + result = strlcpy(page, opts->id, PAGE_SIZE); + mutex_unlock(&opts->lock); + + return result; +} + +static ssize_t f_midi_opts_id_store(struct f_midi_opts *opts, + const char *page, size_t len) +{ + int ret; + char *c; + + mutex_lock(&opts->lock); + if (opts->refcnt) { + ret = -EBUSY; + goto end; + } + + c = kstrndup(page, len, GFP_KERNEL); + if (!c) { + ret = -ENOMEM; + goto end; + } + if (opts->id_allocated) + kfree(opts->id); + opts->id = c; + opts->id_allocated = true; + ret = len; +end: + mutex_unlock(&opts->lock); + return ret; +} + +static struct f_midi_opts_attribute f_midi_opts_id = + __CONFIGFS_ATTR(id, S_IRUGO | S_IWUSR, f_midi_opts_id_show, + f_midi_opts_id_store); + +static struct configfs_attribute *midi_attrs[] = { + &f_midi_opts_index.attr, + &f_midi_opts_buflen.attr, + &f_midi_opts_qlen.attr, + &f_midi_opts_in_ports.attr, + &f_midi_opts_out_ports.attr, + &f_midi_opts_id.attr, + NULL, +}; + +static struct config_item_type midi_func_type = { + .ct_item_ops = &midi_item_ops, + .ct_attrs = midi_attrs, + .ct_owner = THIS_MODULE, +}; + static void f_midi_free_inst(struct usb_function_instance *f) { struct f_midi_opts *opts; opts = container_of(f, struct f_midi_opts, func_inst); + if (opts->id_allocated) + kfree(opts->id); + kfree(opts); } @@ -912,7 +1045,18 @@ static struct usb_function_instance *f_midi_alloc_inst(void) opts = kzalloc(sizeof(*opts), GFP_KERNEL); if (!opts) return ERR_PTR(-ENOMEM); + + mutex_init(&opts->lock); opts->func_inst.free_func_inst = f_midi_free_inst; + opts->index = SNDRV_DEFAULT_IDX1; + opts->id = SNDRV_DEFAULT_STR1; + opts->buflen = 256; + opts->qlen = 32; + opts->in_ports = 1; + opts->out_ports = 1; + + config_group_init_type_name(&opts->func_inst.group, "", + &midi_func_type); return &opts->func_inst; } @@ -926,9 +1070,12 @@ static void f_midi_free(struct usb_function *f) midi = func_to_midi(f); opts = container_of(f->fi, struct f_midi_opts, func_inst); kfree(midi->id); + mutex_lock(&opts->lock); for (i = opts->in_ports - 1; i >= 0; --i) kfree(midi->in_port[i]); kfree(midi); + --opts->refcnt; + mutex_unlock(&opts->lock); } static void f_midi_unbind(struct usb_configuration *c, struct usb_function *f) @@ -957,20 +1104,27 @@ struct usb_function *f_midi_alloc(struct usb_function_instance *fi) int status, i; opts = container_of(fi, struct f_midi_opts, func_inst); + + mutex_lock(&opts->lock); /* sanity check */ - if (opts->in_ports > MAX_PORTS || opts->out_ports > MAX_PORTS) + if (opts->in_ports > MAX_PORTS || opts->out_ports > MAX_PORTS) { + mutex_unlock(&opts->lock); return ERR_PTR(-EINVAL); + } /* allocate and initialize one new instance */ midi = kzalloc(sizeof(*midi), GFP_KERNEL); - if (!midi) + if (!midi) { + mutex_unlock(&opts->lock); return ERR_PTR(-ENOMEM); + } for (i = 0; i < opts->in_ports; i++) { struct gmidi_in_port *port = kzalloc(sizeof(*port), GFP_KERNEL); if (!port) { status = -ENOMEM; + mutex_unlock(&opts->lock); goto setup_fail; } @@ -984,6 +1138,7 @@ struct usb_function *f_midi_alloc(struct usb_function_instance *fi) midi->id = kstrdup(opts->id, GFP_KERNEL); if (opts->id && !midi->id) { status = -ENOMEM; + mutex_unlock(&opts->lock); goto kstrdup_fail; } midi->in_ports = opts->in_ports; @@ -991,6 +1146,8 @@ struct usb_function *f_midi_alloc(struct usb_function_instance *fi) midi->index = opts->index; midi->buflen = opts->buflen; midi->qlen = opts->qlen; + ++opts->refcnt; + mutex_unlock(&opts->lock); midi->func.name = "gmidi function"; midi->func.bind = f_midi_bind; diff --git a/drivers/usb/gadget/function/u_midi.h b/drivers/usb/gadget/function/u_midi.h index 76bccc1fdbb4..22510189758e 100644 --- a/drivers/usb/gadget/function/u_midi.h +++ b/drivers/usb/gadget/function/u_midi.h @@ -22,10 +22,18 @@ struct f_midi_opts { struct usb_function_instance func_inst; int index; char *id; + bool id_allocated; unsigned int in_ports; unsigned int out_ports; unsigned int buflen; unsigned int qlen; + + /* + * Protect the data form concurrent access by read/write + * and create symlink/remove symlink. + */ + struct mutex lock; + int refcnt; }; #endif /* U_MIDI_H */ -- GitLab