diff options
Diffstat (limited to 'drivers/usb/gadget/function/f_midi.c')
| -rw-r--r-- | drivers/usb/gadget/function/f_midi.c | 1408 |
1 files changed, 1408 insertions, 0 deletions
diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c new file mode 100644 index 000000000..fddf53900 --- /dev/null +++ b/drivers/usb/gadget/function/f_midi.c @@ -0,0 +1,1408 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * f_midi.c -- USB MIDI class function driver + * + * Copyright (C) 2006 Thumtronics Pty Ltd. + * Developed for Thumtronics by Grey Innovation + * Ben Williamson <ben.williamson@greyinnovation.com> + * + * Rewritten for the composite framework + * Copyright (C) 2011 Daniel Mack <zonque@gmail.com> + * + * Based on drivers/usb/gadget/f_audio.c, + * Copyright (C) 2008 Bryan Wu <cooloney@kernel.org> + * Copyright (C) 2008 Analog Devices, Inc + * + * and drivers/usb/gadget/midi.c, + * Copyright (C) 2006 Thumtronics Pty Ltd. + * Ben Williamson <ben.williamson@greyinnovation.com> + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/device.h> +#include <linux/kfifo.h> +#include <linux/spinlock.h> + +#include <sound/core.h> +#include <sound/initval.h> +#include <sound/rawmidi.h> + +#include <linux/usb/ch9.h> +#include <linux/usb/gadget.h> +#include <linux/usb/audio.h> +#include <linux/usb/midi.h> + +#include "u_f.h" +#include "u_midi.h" + +MODULE_AUTHOR("Ben Williamson"); +MODULE_LICENSE("GPL v2"); + +static const char f_midi_shortname[] = "f_midi"; +static const char f_midi_longname[] = "MIDI Gadget"; + +/* + * We can only handle 16 cables on one single endpoint, as cable numbers are + * stored in 4-bit fields. And as the interface currently only holds one + * single endpoint, this is the maximum number of ports we can allow. + */ +#define MAX_PORTS 16 + +/* MIDI message states */ +enum { + STATE_INITIAL = 0, /* pseudo state */ + STATE_1PARAM, + STATE_2PARAM_1, + STATE_2PARAM_2, + STATE_SYSEX_0, + STATE_SYSEX_1, + STATE_SYSEX_2, + STATE_REAL_TIME, + STATE_FINISHED, /* pseudo state */ +}; + +/* + * This is a gadget, and the IN/OUT naming is from the host's perspective. + * USB -> OUT endpoint -> rawmidi + * USB <- IN endpoint <- rawmidi + */ +struct gmidi_in_port { + struct snd_rawmidi_substream *substream; + int active; + uint8_t cable; + uint8_t state; + uint8_t data[2]; +}; + +struct f_midi { + struct usb_function func; + struct usb_gadget *gadget; + struct usb_ep *in_ep, *out_ep; + struct snd_card *card; + struct snd_rawmidi *rmidi; + u8 ms_id; + + struct snd_rawmidi_substream *out_substream[MAX_PORTS]; + + unsigned long out_triggered; + struct work_struct work; + unsigned int in_ports; + unsigned int out_ports; + int index; + char *id; + unsigned int buflen, qlen; + /* This fifo is used as a buffer ring for pre-allocated IN usb_requests */ + DECLARE_KFIFO_PTR(in_req_fifo, struct usb_request *); + spinlock_t transmit_lock; + unsigned int in_last_port; + unsigned char free_ref; + + struct gmidi_in_port in_ports_array[/* in_ports */]; +}; + +static inline struct f_midi *func_to_midi(struct usb_function *f) +{ + return container_of(f, struct f_midi, func); +} + +static void f_midi_transmit(struct f_midi *midi); +static void f_midi_rmidi_free(struct snd_rawmidi *rmidi); +static void f_midi_free_inst(struct usb_function_instance *f); + +DECLARE_UAC_AC_HEADER_DESCRIPTOR(1); +DECLARE_USB_MIDI_OUT_JACK_DESCRIPTOR(1); +DECLARE_USB_MS_ENDPOINT_DESCRIPTOR(16); + +/* B.3.1 Standard AC Interface Descriptor */ +static struct usb_interface_descriptor ac_interface_desc = { + .bLength = USB_DT_INTERFACE_SIZE, + .bDescriptorType = USB_DT_INTERFACE, + /* .bInterfaceNumber = DYNAMIC */ + /* .bNumEndpoints = DYNAMIC */ + .bInterfaceClass = USB_CLASS_AUDIO, + .bInterfaceSubClass = USB_SUBCLASS_AUDIOCONTROL, + /* .iInterface = DYNAMIC */ +}; + +/* B.3.2 Class-Specific AC Interface Descriptor */ +static struct uac1_ac_header_descriptor_1 ac_header_desc = { + .bLength = UAC_DT_AC_HEADER_SIZE(1), + .bDescriptorType = USB_DT_CS_INTERFACE, + .bDescriptorSubtype = USB_MS_HEADER, + .bcdADC = cpu_to_le16(0x0100), + .wTotalLength = cpu_to_le16(UAC_DT_AC_HEADER_SIZE(1)), + .bInCollection = 1, + /* .baInterfaceNr = DYNAMIC */ +}; + +/* B.4.1 Standard MS Interface Descriptor */ +static struct usb_interface_descriptor ms_interface_desc = { + .bLength = USB_DT_INTERFACE_SIZE, + .bDescriptorType = USB_DT_INTERFACE, + /* .bInterfaceNumber = DYNAMIC */ + .bNumEndpoints = 2, + .bInterfaceClass = USB_CLASS_AUDIO, + .bInterfaceSubClass = USB_SUBCLASS_MIDISTREAMING, + /* .iInterface = DYNAMIC */ +}; + +/* B.4.2 Class-Specific MS Interface Descriptor */ +static struct usb_ms_header_descriptor ms_header_desc = { + .bLength = USB_DT_MS_HEADER_SIZE, + .bDescriptorType = USB_DT_CS_INTERFACE, + .bDescriptorSubtype = USB_MS_HEADER, + .bcdMSC = cpu_to_le16(0x0100), + /* .wTotalLength = DYNAMIC */ +}; + +/* B.5.1 Standard Bulk OUT Endpoint Descriptor */ +static struct usb_endpoint_descriptor bulk_out_desc = { + .bLength = USB_DT_ENDPOINT_AUDIO_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + .bEndpointAddress = USB_DIR_OUT, + .bmAttributes = USB_ENDPOINT_XFER_BULK, +}; + +static struct usb_ss_ep_comp_descriptor bulk_out_ss_comp_desc = { + .bLength = sizeof(bulk_out_ss_comp_desc), + .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, + /* .bMaxBurst = 0, */ + /* .bmAttributes = 0, */ +}; + +/* B.5.2 Class-specific MS Bulk OUT Endpoint Descriptor */ +static struct usb_ms_endpoint_descriptor_16 ms_out_desc = { + /* .bLength = DYNAMIC */ + .bDescriptorType = USB_DT_CS_ENDPOINT, + .bDescriptorSubtype = USB_MS_GENERAL, + /* .bNumEmbMIDIJack = DYNAMIC */ + /* .baAssocJackID = DYNAMIC */ +}; + +/* B.6.1 Standard Bulk IN Endpoint Descriptor */ +static struct usb_endpoint_descriptor bulk_in_desc = { + .bLength = USB_DT_ENDPOINT_AUDIO_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + .bEndpointAddress = USB_DIR_IN, + .bmAttributes = USB_ENDPOINT_XFER_BULK, +}; + +static struct usb_ss_ep_comp_descriptor bulk_in_ss_comp_desc = { + .bLength = sizeof(bulk_in_ss_comp_desc), + .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, + /* .bMaxBurst = 0, */ + /* .bmAttributes = 0, */ +}; + +/* B.6.2 Class-specific MS Bulk IN Endpoint Descriptor */ +static struct usb_ms_endpoint_descriptor_16 ms_in_desc = { + /* .bLength = DYNAMIC */ + .bDescriptorType = USB_DT_CS_ENDPOINT, + .bDescriptorSubtype = USB_MS_GENERAL, + /* .bNumEmbMIDIJack = DYNAMIC */ + /* .baAssocJackID = DYNAMIC */ +}; + +/* string IDs are assigned dynamically */ + +#define STRING_FUNC_IDX 0 + +static struct usb_string midi_string_defs[] = { + [STRING_FUNC_IDX].s = "MIDI function", + { } /* end of list */ +}; + +static struct usb_gadget_strings midi_stringtab = { + .language = 0x0409, /* en-us */ + .strings = midi_string_defs, +}; + +static struct usb_gadget_strings *midi_strings[] = { + &midi_stringtab, + NULL, +}; + +static inline struct usb_request *midi_alloc_ep_req(struct usb_ep *ep, + unsigned length) +{ + return alloc_ep_req(ep, length); +} + +static const uint8_t f_midi_cin_length[] = { + 0, 0, 2, 3, 3, 1, 2, 3, 3, 3, 3, 3, 2, 2, 3, 1 +}; + +/* + * Receives a chunk of MIDI data. + */ +static void f_midi_read_data(struct usb_ep *ep, int cable, + uint8_t *data, int length) +{ + struct f_midi *midi = ep->driver_data; + struct snd_rawmidi_substream *substream = midi->out_substream[cable]; + + if (!substream) + /* Nobody is listening - throw it on the floor. */ + return; + + if (!test_bit(cable, &midi->out_triggered)) + return; + + snd_rawmidi_receive(substream, data, length); +} + +static void f_midi_handle_out_data(struct usb_ep *ep, struct usb_request *req) +{ + unsigned int i; + u8 *buf = req->buf; + + for (i = 0; i + 3 < req->actual; i += 4) + if (buf[i] != 0) { + int cable = buf[i] >> 4; + int length = f_midi_cin_length[buf[i] & 0x0f]; + f_midi_read_data(ep, cable, &buf[i + 1], length); + } +} + +static void +f_midi_complete(struct usb_ep *ep, struct usb_request *req) +{ + struct f_midi *midi = ep->driver_data; + struct usb_composite_dev *cdev = midi->func.config->cdev; + int status = req->status; + + switch (status) { + case 0: /* normal completion */ + if (ep == midi->out_ep) { + /* We received stuff. req is queued again, below */ + f_midi_handle_out_data(ep, req); + } else if (ep == midi->in_ep) { + /* Our transmit completed. See if there's more to go. + * f_midi_transmit eats req, don't queue it again. */ + req->length = 0; + f_midi_transmit(midi); + return; + } + break; + + /* this endpoint is normally active while we're configured */ + case -ECONNABORTED: /* hardware forced ep reset */ + case -ECONNRESET: /* request dequeued */ + case -ESHUTDOWN: /* disconnect from host */ + VDBG(cdev, "%s gone (%d), %d/%d\n", ep->name, status, + req->actual, req->length); + if (ep == midi->out_ep) { + f_midi_handle_out_data(ep, req); + /* We don't need to free IN requests because it's handled + * by the midi->in_req_fifo. */ + free_ep_req(ep, req); + } + return; + + case -EOVERFLOW: /* buffer overrun on read means that + * we didn't provide a big enough buffer. + */ + default: + DBG(cdev, "%s complete --> %d, %d/%d\n", ep->name, + status, req->actual, req->length); + break; + case -EREMOTEIO: /* short read */ + break; + } + + status = usb_ep_queue(ep, req, GFP_ATOMIC); + if (status) { + ERROR(cdev, "kill %s: resubmit %d bytes --> %d\n", + ep->name, req->length, status); + usb_ep_set_halt(ep); + /* FIXME recover later ... somehow */ + } +} + +static void f_midi_drop_out_substreams(struct f_midi *midi) +{ + unsigned int i; + + for (i = 0; i < midi->in_ports; i++) { + struct gmidi_in_port *port = midi->in_ports_array + i; + struct snd_rawmidi_substream *substream = port->substream; + + if (port->active && substream) + snd_rawmidi_drop_output(substream); + } +} + +static int f_midi_start_ep(struct f_midi *midi, + struct usb_function *f, + struct usb_ep *ep) +{ + int err; + struct usb_composite_dev *cdev = f->config->cdev; + + usb_ep_disable(ep); + + err = config_ep_by_speed(midi->gadget, f, ep); + if (err) { + ERROR(cdev, "can't configure %s: %d\n", ep->name, err); + return err; + } + + err = usb_ep_enable(ep); + if (err) { + ERROR(cdev, "can't start %s: %d\n", ep->name, err); + return err; + } + + ep->driver_data = midi; + + return 0; +} + +static int f_midi_set_alt(struct usb_function *f, unsigned intf, unsigned alt) +{ + struct f_midi *midi = func_to_midi(f); + unsigned i; + int err; + + /* we only set alt for MIDIStreaming interface */ + if (intf != midi->ms_id) + return 0; + + err = f_midi_start_ep(midi, f, midi->in_ep); + if (err) + return err; + + err = f_midi_start_ep(midi, f, midi->out_ep); + if (err) + return err; + + /* pre-allocate write usb requests to use on f_midi_transmit. */ + while (kfifo_avail(&midi->in_req_fifo)) { + struct usb_request *req = + midi_alloc_ep_req(midi->in_ep, midi->buflen); + + if (req == NULL) + return -ENOMEM; + + req->length = 0; + req->complete = f_midi_complete; + + kfifo_put(&midi->in_req_fifo, req); + } + + /* allocate a bunch of read buffers and queue them all at once. */ + for (i = 0; i < midi->qlen && err == 0; i++) { + struct usb_request *req = + midi_alloc_ep_req(midi->out_ep, midi->buflen); + + if (req == NULL) + return -ENOMEM; + + req->complete = f_midi_complete; + err = usb_ep_queue(midi->out_ep, req, GFP_ATOMIC); + if (err) { + ERROR(midi, "%s: couldn't enqueue request: %d\n", + midi->out_ep->name, err); + if (req->buf != NULL) + free_ep_req(midi->out_ep, req); + return err; + } + } + + return 0; +} + +static void f_midi_disable(struct usb_function *f) +{ + struct f_midi *midi = func_to_midi(f); + struct usb_composite_dev *cdev = f->config->cdev; + struct usb_request *req = NULL; + + DBG(cdev, "disable\n"); + + /* + * just disable endpoints, forcing completion of pending i/o. + * all our completion handlers free their requests in this case. + */ + usb_ep_disable(midi->in_ep); + usb_ep_disable(midi->out_ep); + + /* release IN requests */ + while (kfifo_get(&midi->in_req_fifo, &req)) + free_ep_req(midi->in_ep, req); + + f_midi_drop_out_substreams(midi); +} + +static int f_midi_snd_free(struct snd_device *device) +{ + return 0; +} + +/* + * Converts MIDI commands to USB MIDI packets. + */ +static void f_midi_transmit_byte(struct usb_request *req, + struct gmidi_in_port *port, uint8_t b) +{ + uint8_t p[4] = { port->cable << 4, 0, 0, 0 }; + uint8_t next_state = STATE_INITIAL; + + switch (b) { + case 0xf8 ... 0xff: + /* System Real-Time Messages */ + p[0] |= 0x0f; + p[1] = b; + next_state = port->state; + port->state = STATE_REAL_TIME; + break; + + case 0xf7: + /* End of SysEx */ + switch (port->state) { + case STATE_SYSEX_0: + p[0] |= 0x05; + p[1] = 0xf7; + next_state = STATE_FINISHED; + break; + case STATE_SYSEX_1: + p[0] |= 0x06; + p[1] = port->data[0]; + p[2] = 0xf7; + next_state = STATE_FINISHED; + break; + case STATE_SYSEX_2: + p[0] |= 0x07; + p[1] = port->data[0]; + p[2] = port->data[1]; + p[3] = 0xf7; + next_state = STATE_FINISHED; + break; + default: + /* Ignore byte */ + next_state = port->state; + port->state = STATE_INITIAL; + } + break; + + case 0xf0 ... 0xf6: + /* System Common Messages */ + port->data[0] = port->data[1] = 0; + port->state = STATE_INITIAL; + switch (b) { + case 0xf0: + port->data[0] = b; + port->data[1] = 0; + next_state = STATE_SYSEX_1; + break; + case 0xf1: + case 0xf3: + port->data[0] = b; + next_state = STATE_1PARAM; + break; + case 0xf2: + port->data[0] = b; + next_state = STATE_2PARAM_1; + break; + case 0xf4: + case 0xf5: + next_state = STATE_INITIAL; + break; + case 0xf6: + p[0] |= 0x05; + p[1] = 0xf6; + next_state = STATE_FINISHED; + break; + } + break; + + case 0x80 ... 0xef: + /* + * Channel Voice Messages, Channel Mode Messages + * and Control Change Messages. + */ + port->data[0] = b; + port->data[1] = 0; + port->state = STATE_INITIAL; + if (b >= 0xc0 && b <= 0xdf) + next_state = STATE_1PARAM; + else + next_state = STATE_2PARAM_1; + break; + + case 0x00 ... 0x7f: + /* Message parameters */ + switch (port->state) { + case STATE_1PARAM: + if (port->data[0] < 0xf0) + p[0] |= port->data[0] >> 4; + else + p[0] |= 0x02; + + p[1] = port->data[0]; + p[2] = b; + /* This is to allow Running State Messages */ + next_state = STATE_1PARAM; + break; + case STATE_2PARAM_1: + port->data[1] = b; + next_state = STATE_2PARAM_2; + break; + case STATE_2PARAM_2: + if (port->data[0] < 0xf0) + p[0] |= port->data[0] >> 4; + else + p[0] |= 0x03; + + p[1] = port->data[0]; + p[2] = port->data[1]; + p[3] = b; + /* This is to allow Running State Messages */ + next_state = STATE_2PARAM_1; + break; + case STATE_SYSEX_0: + port->data[0] = b; + next_state = STATE_SYSEX_1; + break; + case STATE_SYSEX_1: + port->data[1] = b; + next_state = STATE_SYSEX_2; + break; + case STATE_SYSEX_2: + p[0] |= 0x04; + p[1] = port->data[0]; + p[2] = port->data[1]; + p[3] = b; + next_state = STATE_SYSEX_0; + break; + } + break; + } + + /* States where we have to write into the USB request */ + if (next_state == STATE_FINISHED || + port->state == STATE_SYSEX_2 || + port->state == STATE_1PARAM || + port->state == STATE_2PARAM_2 || + port->state == STATE_REAL_TIME) { + + unsigned int length = req->length; + u8 *buf = (u8 *)req->buf + length; + + memcpy(buf, p, sizeof(p)); + req->length = length + sizeof(p); + + if (next_state == STATE_FINISHED) { + next_state = STATE_INITIAL; + port->data[0] = port->data[1] = 0; + } + } + + port->state = next_state; +} + +static int f_midi_do_transmit(struct f_midi *midi, struct usb_ep *ep) +{ + struct usb_request *req = NULL; + unsigned int len, i; + bool active = false; + int err; + + /* + * We peek the request in order to reuse it if it fails to enqueue on + * its endpoint + */ + len = kfifo_peek(&midi->in_req_fifo, &req); + if (len != 1) { + ERROR(midi, "%s: Couldn't get usb request\n", __func__); + return -1; + } + + /* + * If buffer overrun, then we ignore this transmission. + * IMPORTANT: This will cause the user-space rawmidi device to block + * until a) usb requests have been completed or b) snd_rawmidi_write() + * times out. + */ + if (req->length > 0) + return 0; + + for (i = midi->in_last_port; i < midi->in_ports; ++i) { + struct gmidi_in_port *port = midi->in_ports_array + i; + struct snd_rawmidi_substream *substream = port->substream; + + if (!port->active || !substream) + continue; + + while (req->length + 3 < midi->buflen) { + uint8_t b; + + if (snd_rawmidi_transmit(substream, &b, 1) != 1) { + port->active = 0; + break; + } + f_midi_transmit_byte(req, port, b); + } + + active = !!port->active; + if (active) + break; + } + midi->in_last_port = active ? i : 0; + + if (req->length <= 0) + goto done; + + err = usb_ep_queue(ep, req, GFP_ATOMIC); + if (err < 0) { + ERROR(midi, "%s failed to queue req: %d\n", + midi->in_ep->name, err); + req->length = 0; /* Re-use request next time. */ + } else { + /* Upon success, put request at the back of the queue. */ + kfifo_skip(&midi->in_req_fifo); + kfifo_put(&midi->in_req_fifo, req); + } + +done: + return active; +} + +static void f_midi_transmit(struct f_midi *midi) +{ + struct usb_ep *ep = midi->in_ep; + int ret; + unsigned long flags; + + /* We only care about USB requests if IN endpoint is enabled */ + if (!ep || !ep->enabled) + goto drop_out; + + spin_lock_irqsave(&midi->transmit_lock, flags); + + do { + ret = f_midi_do_transmit(midi, ep); + if (ret < 0) { + spin_unlock_irqrestore(&midi->transmit_lock, flags); + goto drop_out; + } + } while (ret); + + spin_unlock_irqrestore(&midi->transmit_lock, flags); + + return; + +drop_out: + f_midi_drop_out_substreams(midi); +} + +static void f_midi_in_work(struct work_struct *work) +{ + struct f_midi *midi; + + midi = container_of(work, struct f_midi, work); + f_midi_transmit(midi); +} + +static int f_midi_in_open(struct snd_rawmidi_substream *substream) +{ + struct f_midi *midi = substream->rmidi->private_data; + struct gmidi_in_port *port; + + if (substream->number >= midi->in_ports) + return -EINVAL; + + VDBG(midi, "%s()\n", __func__); + port = midi->in_ports_array + substream->number; + port->substream = substream; + port->state = STATE_INITIAL; + return 0; +} + +static int f_midi_in_close(struct snd_rawmidi_substream *substream) +{ + struct f_midi *midi = substream->rmidi->private_data; + + VDBG(midi, "%s()\n", __func__); + return 0; +} + +static void f_midi_in_trigger(struct snd_rawmidi_substream *substream, int up) +{ + struct f_midi *midi = substream->rmidi->private_data; + + if (substream->number >= midi->in_ports) + return; + + VDBG(midi, "%s() %d\n", __func__, up); + midi->in_ports_array[substream->number].active = up; + if (up) + queue_work(system_highpri_wq, &midi->work); +} + +static int f_midi_out_open(struct snd_rawmidi_substream *substream) +{ + struct f_midi *midi = substream->rmidi->private_data; + + if (substream->number >= MAX_PORTS) + return -EINVAL; + + VDBG(midi, "%s()\n", __func__); + midi->out_substream[substream->number] = substream; + return 0; +} + +static int f_midi_out_close(struct snd_rawmidi_substream *substream) +{ + struct f_midi *midi = substream->rmidi->private_data; + + VDBG(midi, "%s()\n", __func__); + return 0; +} + +static void f_midi_out_trigger(struct snd_rawmidi_substream *substream, int up) +{ + struct f_midi *midi = substream->rmidi->private_data; + + VDBG(midi, "%s()\n", __func__); + + if (up) + set_bit(substream->number, &midi->out_triggered); + else + clear_bit(substream->number, &midi->out_triggered); +} + +static const struct snd_rawmidi_ops gmidi_in_ops = { + .open = f_midi_in_open, + .close = f_midi_in_close, + .trigger = f_midi_in_trigger, +}; + +static const struct snd_rawmidi_ops gmidi_out_ops = { + .open = f_midi_out_open, + .close = f_midi_out_close, + .trigger = f_midi_out_trigger +}; + +static inline void f_midi_unregister_card(struct f_midi *midi) +{ + if (midi->card) { + snd_card_free(midi->card); + midi->card = NULL; + } +} + +/* register as a sound "card" */ +static int f_midi_register_card(struct f_midi *midi) +{ + struct snd_card *card; + struct snd_rawmidi *rmidi; + int err; + static struct snd_device_ops ops = { + .dev_free = f_midi_snd_free, + }; + + err = snd_card_new(&midi->gadget->dev, midi->index, midi->id, + THIS_MODULE, 0, &card); + if (err < 0) { + ERROR(midi, "snd_card_new() failed\n"); + goto fail; + } + midi->card = card; + + err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, midi, &ops); + if (err < 0) { + ERROR(midi, "snd_device_new() failed: error %d\n", err); + goto fail; + } + + strcpy(card->driver, f_midi_longname); + strcpy(card->longname, f_midi_longname); + strcpy(card->shortname, f_midi_shortname); + + /* Set up rawmidi */ + snd_component_add(card, "MIDI"); + err = snd_rawmidi_new(card, card->longname, 0, + midi->out_ports, midi->in_ports, &rmidi); + if (err < 0) { + ERROR(midi, "snd_rawmidi_new() failed: error %d\n", err); + goto fail; + } + midi->rmidi = rmidi; + midi->in_last_port = 0; + strcpy(rmidi->name, card->shortname); + rmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT | + SNDRV_RAWMIDI_INFO_INPUT | + SNDRV_RAWMIDI_INFO_DUPLEX; + rmidi->private_data = midi; + rmidi->private_free = f_midi_rmidi_free; + midi->free_ref++; + + /* + * Yes, rawmidi OUTPUT = USB IN, and rawmidi INPUT = USB OUT. + * It's an upside-down world being a gadget. + */ + snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &gmidi_in_ops); + snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &gmidi_out_ops); + + /* register it - we're ready to go */ + err = snd_card_register(card); + if (err < 0) { + ERROR(midi, "snd_card_register() failed\n"); + goto fail; + } + + VDBG(midi, "%s() finished ok\n", __func__); + return 0; + +fail: + f_midi_unregister_card(midi); + return err; +} + +/* MIDI function driver setup/binding */ + +static int f_midi_bind(struct usb_configuration *c, struct usb_function *f) +{ + struct usb_descriptor_header **midi_function; + struct usb_midi_in_jack_descriptor jack_in_ext_desc[MAX_PORTS]; + struct usb_midi_in_jack_descriptor jack_in_emb_desc[MAX_PORTS]; + struct usb_midi_out_jack_descriptor_1 jack_out_ext_desc[MAX_PORTS]; + struct usb_midi_out_jack_descriptor_1 jack_out_emb_desc[MAX_PORTS]; + struct usb_composite_dev *cdev = c->cdev; + struct f_midi *midi = func_to_midi(f); + struct usb_string *us; + int status, n, jack = 1, i = 0, endpoint_descriptor_index = 0; + + midi->gadget = cdev->gadget; + INIT_WORK(&midi->work, f_midi_in_work); + status = f_midi_register_card(midi); + if (status < 0) + goto fail_register; + + /* maybe allocate device-global string ID */ + us = usb_gstrings_attach(c->cdev, midi_strings, + ARRAY_SIZE(midi_string_defs)); + if (IS_ERR(us)) { + status = PTR_ERR(us); + goto fail; + } + ac_interface_desc.iInterface = us[STRING_FUNC_IDX].id; + + /* We have two interfaces, AudioControl and MIDIStreaming */ + status = usb_interface_id(c, f); + if (status < 0) + goto fail; + ac_interface_desc.bInterfaceNumber = status; + + status = usb_interface_id(c, f); + if (status < 0) + goto fail; + ms_interface_desc.bInterfaceNumber = status; + ac_header_desc.baInterfaceNr[0] = status; + midi->ms_id = status; + + status = -ENODEV; + + /* allocate instance-specific endpoints */ + midi->in_ep = usb_ep_autoconfig(cdev->gadget, &bulk_in_desc); + if (!midi->in_ep) + goto fail; + + midi->out_ep = usb_ep_autoconfig(cdev->gadget, &bulk_out_desc); + if (!midi->out_ep) + goto fail; + + /* allocate temporary function list */ + midi_function = kcalloc((MAX_PORTS * 4) + 11, sizeof(*midi_function), + GFP_KERNEL); + if (!midi_function) { + status = -ENOMEM; + goto fail; + } + + /* + * construct the function's descriptor set. As the number of + * input and output MIDI ports is configurable, we have to do + * it that way. + */ + + /* add the headers - these are always the same */ + midi_function[i++] = (struct usb_descriptor_header *) &ac_interface_desc; + midi_function[i++] = (struct usb_descriptor_header *) &ac_header_desc; + midi_function[i++] = (struct usb_descriptor_header *) &ms_interface_desc; + + /* calculate the header's wTotalLength */ + n = USB_DT_MS_HEADER_SIZE + + (midi->in_ports + midi->out_ports) * + (USB_DT_MIDI_IN_SIZE + USB_DT_MIDI_OUT_SIZE(1)); + ms_header_desc.wTotalLength = cpu_to_le16(n); + + midi_function[i++] = (struct usb_descriptor_header *) &ms_header_desc; + + /* configure the external IN jacks, each linked to an embedded OUT jack */ + for (n = 0; n < midi->in_ports; n++) { + struct usb_midi_in_jack_descriptor *in_ext = &jack_in_ext_desc[n]; + struct usb_midi_out_jack_descriptor_1 *out_emb = &jack_out_emb_desc[n]; + + in_ext->bLength = USB_DT_MIDI_IN_SIZE; + in_ext->bDescriptorType = USB_DT_CS_INTERFACE; + in_ext->bDescriptorSubtype = USB_MS_MIDI_IN_JACK; + in_ext->bJackType = USB_MS_EXTERNAL; + in_ext->bJackID = jack++; + in_ext->iJack = 0; + midi_function[i++] = (struct usb_descriptor_header *) in_ext; + + out_emb->bLength = USB_DT_MIDI_OUT_SIZE(1); + out_emb->bDescriptorType = USB_DT_CS_INTERFACE; + out_emb->bDescriptorSubtype = USB_MS_MIDI_OUT_JACK; + out_emb->bJackType = USB_MS_EMBEDDED; + out_emb->bJackID = jack++; + out_emb->bNrInputPins = 1; + out_emb->pins[0].baSourcePin = 1; + out_emb->pins[0].baSourceID = in_ext->bJackID; + out_emb->iJack = 0; + midi_function[i++] = (struct usb_descriptor_header *) out_emb; + + /* link it to the endpoint */ + ms_in_desc.baAssocJackID[n] = out_emb->bJackID; + } + + /* configure the external OUT jacks, each linked to an embedded IN jack */ + for (n = 0; n < midi->out_ports; n++) { + struct usb_midi_in_jack_descriptor *in_emb = &jack_in_emb_desc[n]; + struct usb_midi_out_jack_descriptor_1 *out_ext = &jack_out_ext_desc[n]; + + in_emb->bLength = USB_DT_MIDI_IN_SIZE; + in_emb->bDescriptorType = USB_DT_CS_INTERFACE; + in_emb->bDescriptorSubtype = USB_MS_MIDI_IN_JACK; + in_emb->bJackType = USB_MS_EMBEDDED; + in_emb->bJackID = jack++; + in_emb->iJack = 0; + midi_function[i++] = (struct usb_descriptor_header *) in_emb; + + out_ext->bLength = USB_DT_MIDI_OUT_SIZE(1); + out_ext->bDescriptorType = USB_DT_CS_INTERFACE; + out_ext->bDescriptorSubtype = USB_MS_MIDI_OUT_JACK; + out_ext->bJackType = USB_MS_EXTERNAL; + out_ext->bJackID = jack++; + out_ext->bNrInputPins = 1; + out_ext->iJack = 0; + out_ext->pins[0].baSourceID = in_emb->bJackID; + out_ext->pins[0].baSourcePin = 1; + midi_function[i++] = (struct usb_descriptor_header *) out_ext; + + /* link it to the endpoint */ + ms_out_desc.baAssocJackID[n] = in_emb->bJackID; + } + + /* configure the endpoint descriptors ... */ + ms_out_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->in_ports); + ms_out_desc.bNumEmbMIDIJack = midi->in_ports; + + ms_in_desc.bLength = USB_DT_MS_ENDPOINT_SIZE(midi->out_ports); + ms_in_desc.bNumEmbMIDIJack = midi->out_ports; + + /* ... and add them to the list */ + endpoint_descriptor_index = i; + midi_function[i++] = (struct usb_descriptor_header *) &bulk_out_desc; + midi_function[i++] = (struct usb_descriptor_header *) &ms_out_desc; + midi_function[i++] = (struct usb_descriptor_header *) &bulk_in_desc; + midi_function[i++] = (struct usb_descriptor_header *) &ms_in_desc; + midi_function[i++] = NULL; + + /* + * support all relevant hardware speeds... we expect that when + * hardware is dual speed, all bulk-capable endpoints work at + * both speeds + */ + /* copy descriptors, and track endpoint copies */ + f->fs_descriptors = usb_copy_descriptors(midi_function); + if (!f->fs_descriptors) + goto fail_f_midi; + + if (gadget_is_dualspeed(c->cdev->gadget)) { + bulk_in_desc.wMaxPacketSize = cpu_to_le16(512); + bulk_out_desc.wMaxPacketSize = cpu_to_le16(512); + f->hs_descriptors = usb_copy_descriptors(midi_function); + if (!f->hs_descriptors) + goto fail_f_midi; + } + + if (gadget_is_superspeed(c->cdev->gadget)) { + bulk_in_desc.wMaxPacketSize = cpu_to_le16(1024); + bulk_out_desc.wMaxPacketSize = cpu_to_le16(1024); + i = endpoint_descriptor_index; + midi_function[i++] = (struct usb_descriptor_header *) + &bulk_out_desc; + midi_function[i++] = (struct usb_descriptor_header *) + &bulk_out_ss_comp_desc; + midi_function[i++] = (struct usb_descriptor_header *) + &ms_out_desc; + midi_function[i++] = (struct usb_descriptor_header *) + &bulk_in_desc; + midi_function[i++] = (struct usb_descriptor_header *) + &bulk_in_ss_comp_desc; + midi_function[i++] = (struct usb_descriptor_header *) + &ms_in_desc; + f->ss_descriptors = usb_copy_descriptors(midi_function); + if (!f->ss_descriptors) + goto fail_f_midi; + + if (gadget_is_superspeed_plus(c->cdev->gadget)) { + f->ssp_descriptors = usb_copy_descriptors(midi_function); + if (!f->ssp_descriptors) + goto fail_f_midi; + } + } + + kfree(midi_function); + + return 0; + +fail_f_midi: + kfree(midi_function); + usb_free_all_descriptors(f); +fail: + f_midi_unregister_card(midi); +fail_register: + ERROR(cdev, "%s: can't bind, err %d\n", f->name, status); + + 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); +} + +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, +}; + +#define F_MIDI_OPT(name, test_limit, limit) \ +static ssize_t f_midi_opts_##name##_show(struct config_item *item, char *page) \ +{ \ + struct f_midi_opts *opts = to_f_midi_opts(item); \ + int result; \ + \ + mutex_lock(&opts->lock); \ + result = sprintf(page, "%u\n", opts->name); \ + mutex_unlock(&opts->lock); \ + \ + return result; \ +} \ + \ +static ssize_t f_midi_opts_##name##_store(struct config_item *item, \ + const char *page, size_t len) \ +{ \ + struct f_midi_opts *opts = to_f_midi_opts(item); \ + int ret; \ + u32 num; \ + \ + mutex_lock(&opts->lock); \ + if (opts->refcnt > 1) { \ + 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; \ +} \ + \ +CONFIGFS_ATTR(f_midi_opts_, name); + +#define F_MIDI_OPT_SIGNED(name, test_limit, limit) \ +static ssize_t f_midi_opts_##name##_show(struct config_item *item, char *page) \ +{ \ + struct f_midi_opts *opts = to_f_midi_opts(item); \ + 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 config_item *item, \ + const char *page, size_t len) \ +{ \ + struct f_midi_opts *opts = to_f_midi_opts(item); \ + int ret; \ + s32 num; \ + \ + mutex_lock(&opts->lock); \ + if (opts->refcnt > 1) { \ + ret = -EBUSY; \ + goto end; \ + } \ + \ + ret = kstrtos32(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; \ +} \ + \ +CONFIGFS_ATTR(f_midi_opts_, name); + +F_MIDI_OPT_SIGNED(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 config_item *item, char *page) +{ + struct f_midi_opts *opts = to_f_midi_opts(item); + int result; + + mutex_lock(&opts->lock); + if (opts->id) { + result = strlcpy(page, opts->id, PAGE_SIZE); + } else { + page[0] = 0; + result = 0; + } + + mutex_unlock(&opts->lock); + + return result; +} + +static ssize_t f_midi_opts_id_store(struct config_item *item, + const char *page, size_t len) +{ + struct f_midi_opts *opts = to_f_midi_opts(item); + int ret; + char *c; + + mutex_lock(&opts->lock); + if (opts->refcnt > 1) { + 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; +} + +CONFIGFS_ATTR(f_midi_opts_, id); + +static struct configfs_attribute *midi_attrs[] = { + &f_midi_opts_attr_index, + &f_midi_opts_attr_buflen, + &f_midi_opts_attr_qlen, + &f_midi_opts_attr_in_ports, + &f_midi_opts_attr_out_ports, + &f_midi_opts_attr_id, + NULL, +}; + +static const 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; + bool free = false; + + opts = container_of(f, struct f_midi_opts, func_inst); + + mutex_lock(&opts->lock); + if (!--opts->refcnt) { + free = true; + } + mutex_unlock(&opts->lock); + + if (free) { + if (opts->id_allocated) + kfree(opts->id); + kfree(opts); + } +} + +static struct usb_function_instance *f_midi_alloc_inst(void) +{ + struct f_midi_opts *opts; + + 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 = 512; + opts->qlen = 32; + opts->in_ports = 1; + opts->out_ports = 1; + opts->refcnt = 1; + + config_group_init_type_name(&opts->func_inst.group, "", + &midi_func_type); + + return &opts->func_inst; +} + +static void f_midi_free(struct usb_function *f) +{ + struct f_midi *midi; + struct f_midi_opts *opts; + bool free = false; + + midi = func_to_midi(f); + opts = container_of(f->fi, struct f_midi_opts, func_inst); + mutex_lock(&opts->lock); + if (!--midi->free_ref) { + kfree(midi->id); + kfifo_free(&midi->in_req_fifo); + kfree(midi); + free = true; + } + mutex_unlock(&opts->lock); + + if (free) + f_midi_free_inst(&opts->func_inst); +} + +static void f_midi_rmidi_free(struct snd_rawmidi *rmidi) +{ + f_midi_free(rmidi->private_data); +} + +static void f_midi_unbind(struct usb_configuration *c, struct usb_function *f) +{ + struct usb_composite_dev *cdev = f->config->cdev; + struct f_midi *midi = func_to_midi(f); + struct snd_card *card; + + DBG(cdev, "unbind\n"); + + /* just to be sure */ + f_midi_disable(f); + + card = midi->card; + midi->card = NULL; + if (card) + snd_card_free_when_closed(card); + + usb_free_all_descriptors(f); +} + +static struct usb_function *f_midi_alloc(struct usb_function_instance *fi) +{ + struct f_midi *midi = NULL; + struct f_midi_opts *opts; + 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) { + status = -EINVAL; + goto setup_fail; + } + + /* allocate and initialize one new instance */ + midi = kzalloc(struct_size(midi, in_ports_array, opts->in_ports), + GFP_KERNEL); + if (!midi) { + status = -ENOMEM; + goto setup_fail; + } + + for (i = 0; i < opts->in_ports; i++) + midi->in_ports_array[i].cable = i; + + /* set up ALSA midi devices */ + midi->id = kstrdup(opts->id, GFP_KERNEL); + if (opts->id && !midi->id) { + status = -ENOMEM; + goto midi_free; + } + midi->in_ports = opts->in_ports; + midi->out_ports = opts->out_ports; + midi->index = opts->index; + midi->buflen = opts->buflen; + midi->qlen = opts->qlen; + midi->in_last_port = 0; + midi->free_ref = 1; + + status = kfifo_alloc(&midi->in_req_fifo, midi->qlen, GFP_KERNEL); + if (status) + goto midi_free; + + spin_lock_init(&midi->transmit_lock); + + ++opts->refcnt; + mutex_unlock(&opts->lock); + + midi->func.name = "gmidi function"; + midi->func.bind = f_midi_bind; + midi->func.unbind = f_midi_unbind; + midi->func.set_alt = f_midi_set_alt; + midi->func.disable = f_midi_disable; + midi->func.free_func = f_midi_free; + + return &midi->func; + +midi_free: + if (midi) + kfree(midi->id); + kfree(midi); +setup_fail: + mutex_unlock(&opts->lock); + + return ERR_PTR(status); +} + +DECLARE_USB_FUNCTION_INIT(midi, f_midi_alloc_inst, f_midi_alloc); |