296 lines
		
	
	
		
			8.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			296 lines
		
	
	
		
			8.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * ff-transaction.c - a part of driver for RME Fireface series
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|  *
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|  * Copyright (c) 2015-2017 Takashi Sakamoto
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|  *
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|  * Licensed under the terms of the GNU General Public License, version 2.
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|  */
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| 
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| #include "ff.h"
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| 
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| static void finish_transmit_midi_msg(struct snd_ff *ff, unsigned int port,
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| 				     int rcode)
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| {
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| 	struct snd_rawmidi_substream *substream =
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| 				READ_ONCE(ff->rx_midi_substreams[port]);
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| 
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| 	if (rcode_is_permanent_error(rcode)) {
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| 		ff->rx_midi_error[port] = true;
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| 		return;
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| 	}
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| 
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| 	if (rcode != RCODE_COMPLETE) {
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| 		/* Transfer the message again, immediately. */
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| 		ff->next_ktime[port] = 0;
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| 		schedule_work(&ff->rx_midi_work[port]);
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| 		return;
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| 	}
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| 
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| 	snd_rawmidi_transmit_ack(substream, ff->rx_bytes[port]);
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| 	ff->rx_bytes[port] = 0;
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| 
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| 	if (!snd_rawmidi_transmit_empty(substream))
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| 		schedule_work(&ff->rx_midi_work[port]);
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| }
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| 
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| static void finish_transmit_midi0_msg(struct fw_card *card, int rcode,
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| 				      void *data, size_t length,
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| 				      void *callback_data)
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| {
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| 	struct snd_ff *ff =
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| 		container_of(callback_data, struct snd_ff, transactions[0]);
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| 	finish_transmit_midi_msg(ff, 0, rcode);
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| }
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| 
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| static void finish_transmit_midi1_msg(struct fw_card *card, int rcode,
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| 				      void *data, size_t length,
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| 				      void *callback_data)
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| {
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| 	struct snd_ff *ff =
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| 		container_of(callback_data, struct snd_ff, transactions[1]);
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| 	finish_transmit_midi_msg(ff, 1, rcode);
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| }
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| 
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| static inline void fill_midi_buf(struct snd_ff *ff, unsigned int port,
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| 				 unsigned int index, u8 byte)
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| {
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| 	ff->msg_buf[port][index] = cpu_to_le32(byte);
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| }
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| 
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| static void transmit_midi_msg(struct snd_ff *ff, unsigned int port)
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| {
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| 	struct snd_rawmidi_substream *substream =
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| 			READ_ONCE(ff->rx_midi_substreams[port]);
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| 	u8 *buf = (u8 *)ff->msg_buf[port];
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| 	int i, len;
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| 
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| 	struct fw_device *fw_dev = fw_parent_device(ff->unit);
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| 	unsigned long long addr;
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| 	int generation;
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| 	fw_transaction_callback_t callback;
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| 
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| 	if (substream == NULL || snd_rawmidi_transmit_empty(substream))
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| 		return;
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| 
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| 	if (ff->rx_bytes[port] > 0 || ff->rx_midi_error[port])
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| 		return;
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| 
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| 	/* Do it in next chance. */
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| 	if (ktime_after(ff->next_ktime[port], ktime_get())) {
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| 		schedule_work(&ff->rx_midi_work[port]);
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| 		return;
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| 	}
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| 
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| 	len = snd_rawmidi_transmit_peek(substream, buf,
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| 					SND_FF_MAXIMIM_MIDI_QUADS);
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| 	if (len <= 0)
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| 		return;
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| 
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| 	for (i = len - 1; i >= 0; i--)
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| 		fill_midi_buf(ff, port, i, buf[i]);
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| 
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| 	if (port == 0) {
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| 		addr = ff->spec->protocol->midi_rx_port_0_reg;
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| 		callback = finish_transmit_midi0_msg;
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| 	} else {
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| 		addr = ff->spec->protocol->midi_rx_port_1_reg;
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| 		callback = finish_transmit_midi1_msg;
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| 	}
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| 
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| 	/* Set interval to next transaction. */
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| 	ff->next_ktime[port] = ktime_add_ns(ktime_get(),
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| 					    len * 8 * NSEC_PER_SEC / 31250);
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| 	ff->rx_bytes[port] = len;
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| 
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| 	/*
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| 	 * In Linux FireWire core, when generation is updated with memory
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| 	 * barrier, node id has already been updated. In this module, After
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| 	 * this smp_rmb(), load/store instructions to memory are completed.
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| 	 * Thus, both of generation and node id are available with recent
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| 	 * values. This is a light-serialization solution to handle bus reset
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| 	 * events on IEEE 1394 bus.
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| 	 */
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| 	generation = fw_dev->generation;
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| 	smp_rmb();
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| 	fw_send_request(fw_dev->card, &ff->transactions[port],
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| 			TCODE_WRITE_BLOCK_REQUEST,
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| 			fw_dev->node_id, generation, fw_dev->max_speed,
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| 			addr, &ff->msg_buf[port], len * 4,
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| 			callback, &ff->transactions[port]);
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| }
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| 
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| static void transmit_midi0_msg(struct work_struct *work)
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| {
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| 	struct snd_ff *ff = container_of(work, struct snd_ff, rx_midi_work[0]);
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| 
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| 	transmit_midi_msg(ff, 0);
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| }
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| 
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| static void transmit_midi1_msg(struct work_struct *work)
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| {
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| 	struct snd_ff *ff = container_of(work, struct snd_ff, rx_midi_work[1]);
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| 
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| 	transmit_midi_msg(ff, 1);
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| }
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| 
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| static void handle_midi_msg(struct fw_card *card, struct fw_request *request,
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| 			    int tcode, int destination, int source,
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| 			    int generation, unsigned long long offset,
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| 			    void *data, size_t length, void *callback_data)
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| {
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| 	struct snd_ff *ff = callback_data;
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| 	__le32 *buf = data;
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| 	u32 quad;
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| 	u8 byte;
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| 	unsigned int index;
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| 	struct snd_rawmidi_substream *substream;
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| 	int i;
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| 
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| 	fw_send_response(card, request, RCODE_COMPLETE);
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| 
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| 	for (i = 0; i < length / 4; i++) {
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| 		quad = le32_to_cpu(buf[i]);
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| 
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| 		/* Message in first port. */
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| 		/*
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| 		 * This value may represent the index of this unit when the same
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| 		 * units are on the same IEEE 1394 bus. This driver doesn't use
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| 		 * it.
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| 		 */
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| 		index = (quad >> 8) & 0xff;
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| 		if (index > 0) {
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| 			substream = READ_ONCE(ff->tx_midi_substreams[0]);
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| 			if (substream != NULL) {
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| 				byte = quad & 0xff;
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| 				snd_rawmidi_receive(substream, &byte, 1);
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| 			}
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| 		}
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| 
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| 		/* Message in second port. */
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| 		index = (quad >> 24) & 0xff;
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| 		if (index > 0) {
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| 			substream = READ_ONCE(ff->tx_midi_substreams[1]);
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| 			if (substream != NULL) {
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| 				byte = (quad >> 16) & 0xff;
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| 				snd_rawmidi_receive(substream, &byte, 1);
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| 			}
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| 		}
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| 	}
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| }
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| 
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| static int allocate_own_address(struct snd_ff *ff, int i)
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| {
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| 	struct fw_address_region midi_msg_region;
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| 	int err;
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| 
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| 	ff->async_handler.length = SND_FF_MAXIMIM_MIDI_QUADS * 4;
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| 	ff->async_handler.address_callback = handle_midi_msg;
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| 	ff->async_handler.callback_data = ff;
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| 
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| 	midi_msg_region.start = 0x000100000000ull * i;
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| 	midi_msg_region.end = midi_msg_region.start + ff->async_handler.length;
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| 
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| 	err = fw_core_add_address_handler(&ff->async_handler, &midi_msg_region);
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| 	if (err >= 0) {
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| 		/* Controllers are allowed to register this region. */
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| 		if (ff->async_handler.offset & 0x0000ffffffff) {
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| 			fw_core_remove_address_handler(&ff->async_handler);
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| 			err = -EAGAIN;
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| 		}
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| 	}
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| 
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| 	return err;
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| }
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| 
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| /*
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|  * The configuration to start asynchronous transactions for MIDI messages is in
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|  * 0x'0000'8010'051c. This register includes the other options, thus this driver
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|  * doesn't touch it and leaves the decision to userspace. The userspace MUST add
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|  * 0x04000000 to write transactions to the register to receive any MIDI
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|  * messages.
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|  *
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|  * Here, I just describe MIDI-related offsets of the register, in little-endian
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|  * order.
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|  *
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|  * Controllers are allowed to register higher 4 bytes of address to receive
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|  * the transactions. The register is 0x'0000'8010'03f4. On the other hand, the
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|  * controllers are not allowed to register lower 4 bytes of the address. They
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|  * are forced to select from 4 options by writing corresponding bits to
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|  * 0x'0000'8010'051c.
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|  *
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|  * The 3rd-6th bits in MSB of this register are used to indicate lower 4 bytes
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|  * of address to which the device transferrs the transactions.
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|  *  - 6th: 0x'....'....'0000'0180
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|  *  - 5th: 0x'....'....'0000'0100
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|  *  - 4th: 0x'....'....'0000'0080
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|  *  - 3rd: 0x'....'....'0000'0000
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|  *
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|  * This driver configure 0x'....'....'0000'0000 for units to receive MIDI
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|  * messages. 3rd bit of the register should be configured, however this driver
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|  * deligates this task to user space applications due to a restriction that
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|  * this register is write-only and the other bits have own effects.
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|  *
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|  * The 1st and 2nd bits in LSB of this register are used to cancel transferring
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|  * asynchronous transactions. These two bits have the same effect.
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|  *  - 1st/2nd: cancel transferring
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|  */
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| int snd_ff_transaction_reregister(struct snd_ff *ff)
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| {
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| 	struct fw_card *fw_card = fw_parent_device(ff->unit)->card;
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| 	u32 addr;
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| 	__le32 reg;
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| 
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| 	/*
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| 	 * Controllers are allowed to register its node ID and upper 2 byte of
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| 	 * local address to listen asynchronous transactions.
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| 	 */
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| 	addr = (fw_card->node_id << 16) | (ff->async_handler.offset >> 32);
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| 	reg = cpu_to_le32(addr);
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| 	return snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
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| 				  ff->spec->protocol->midi_high_addr_reg,
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| 				  ®, sizeof(reg), 0);
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| }
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| 
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| int snd_ff_transaction_register(struct snd_ff *ff)
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| {
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| 	int i, err;
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| 
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| 	/*
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| 	 * Allocate in Memory Space of IEC 13213, but lower 4 byte in LSB should
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| 	 * be zero due to device specification.
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| 	 */
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| 	for (i = 0; i < 0xffff; i++) {
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| 		err = allocate_own_address(ff, i);
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| 		if (err != -EBUSY && err != -EAGAIN)
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| 			break;
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| 	}
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| 	if (err < 0)
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| 		return err;
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| 
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| 	err = snd_ff_transaction_reregister(ff);
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| 	if (err < 0)
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| 		return err;
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| 
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| 	INIT_WORK(&ff->rx_midi_work[0], transmit_midi0_msg);
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| 	INIT_WORK(&ff->rx_midi_work[1], transmit_midi1_msg);
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| 
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| 	return 0;
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| }
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| 
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| void snd_ff_transaction_unregister(struct snd_ff *ff)
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| {
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| 	__le32 reg;
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| 
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| 	if (ff->async_handler.callback_data == NULL)
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| 		return;
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| 	ff->async_handler.callback_data = NULL;
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| 
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| 	/* Release higher 4 bytes of address. */
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| 	reg = cpu_to_le32(0x00000000);
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| 	snd_fw_transaction(ff->unit, TCODE_WRITE_QUADLET_REQUEST,
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| 			   ff->spec->protocol->midi_high_addr_reg,
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| 			   ®, sizeof(reg), 0);
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| 
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| 	fw_core_remove_address_handler(&ff->async_handler);
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| }
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