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usb: gadget: f_midi: add configfs support 

Make the midi function available for gadgets composed with configfs.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
hifive-unleashed-5.1
Andrzej Pietrasiewicz 2014-10-16 13:33:31 +02:00 committed by Felipe Balbi
parent 9caa0d77f7
commit 6f1de34455
4 changed files with 193 additions and 2 deletions
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12
Documentation/ABI/testing/configfs-usb-gadget-midi 100644
View File

@ -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

14
drivers/usb/gadget/Kconfig
View File

@ -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

161
drivers/usb/gadget/function/f_midi.c
View File

@ -896,12 +896,145 @@ fail_register:
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;

8
drivers/usb/gadget/function/u_midi.h
View File

@ -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 */