375 lines
10 KiB
C
375 lines
10 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* serial-generic.c
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* Copyright (c) by Daniel Kaehn <kaehndan@gmail.com
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* Based on serial-u16550.c by Jaroslav Kysela <perex@perex.cz>,
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* Isaku Yamahata <yamahata@private.email.ne.jp>,
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* George Hansper <ghansper@apana.org.au>,
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* Hannu Savolainen
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*
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* Generic serial MIDI driver using the serdev serial bus API for hardware interaction
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*/
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/io.h>
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#include <linux/ioport.h>
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#include <linux/module.h>
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#include <linux/of_device.h>
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#include <linux/serdev.h>
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#include <linux/serial_reg.h>
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#include <linux/slab.h>
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#include <linux/dev_printk.h>
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#include <sound/core.h>
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#include <sound/rawmidi.h>
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#include <sound/initval.h>
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MODULE_DESCRIPTION("Generic serial MIDI driver");
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MODULE_LICENSE("GPL");
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#define SERIAL_MODE_INPUT_OPEN 1
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#define SERIAL_MODE_OUTPUT_OPEN 2
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#define SERIAL_MODE_INPUT_TRIGGERED 3
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#define SERIAL_MODE_OUTPUT_TRIGGERED 4
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#define SERIAL_TX_STATE_ACTIVE 1
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#define SERIAL_TX_STATE_WAKEUP 2
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struct snd_serial_generic {
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struct serdev_device *serdev;
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struct snd_card *card;
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struct snd_rawmidi *rmidi;
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struct snd_rawmidi_substream *midi_output;
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struct snd_rawmidi_substream *midi_input;
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unsigned int baudrate;
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unsigned long filemode; /* open status of file */
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struct work_struct tx_work;
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unsigned long tx_state;
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};
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static void snd_serial_generic_tx_wakeup(struct snd_serial_generic *drvdata)
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{
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if (test_and_set_bit(SERIAL_TX_STATE_ACTIVE, &drvdata->tx_state))
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set_bit(SERIAL_TX_STATE_WAKEUP, &drvdata->tx_state);
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schedule_work(&drvdata->tx_work);
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}
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#define INTERNAL_BUF_SIZE 256
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static void snd_serial_generic_tx_work(struct work_struct *work)
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{
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static char buf[INTERNAL_BUF_SIZE];
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int num_bytes;
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struct snd_serial_generic *drvdata = container_of(work, struct snd_serial_generic,
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tx_work);
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struct snd_rawmidi_substream *substream = drvdata->midi_output;
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clear_bit(SERIAL_TX_STATE_WAKEUP, &drvdata->tx_state);
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while (!snd_rawmidi_transmit_empty(substream)) {
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if (!test_bit(SERIAL_MODE_OUTPUT_OPEN, &drvdata->filemode))
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break;
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num_bytes = snd_rawmidi_transmit_peek(substream, buf, INTERNAL_BUF_SIZE);
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num_bytes = serdev_device_write_buf(drvdata->serdev, buf, num_bytes);
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if (!num_bytes)
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break;
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snd_rawmidi_transmit_ack(substream, num_bytes);
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if (!test_bit(SERIAL_TX_STATE_WAKEUP, &drvdata->tx_state))
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break;
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}
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clear_bit(SERIAL_TX_STATE_ACTIVE, &drvdata->tx_state);
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}
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static void snd_serial_generic_write_wakeup(struct serdev_device *serdev)
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{
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struct snd_serial_generic *drvdata = serdev_device_get_drvdata(serdev);
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snd_serial_generic_tx_wakeup(drvdata);
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}
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static int snd_serial_generic_receive_buf(struct serdev_device *serdev,
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const unsigned char *buf, size_t count)
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{
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int ret;
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struct snd_serial_generic *drvdata = serdev_device_get_drvdata(serdev);
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if (!test_bit(SERIAL_MODE_INPUT_OPEN, &drvdata->filemode))
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return 0;
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ret = snd_rawmidi_receive(drvdata->midi_input, buf, count);
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return ret < 0 ? 0 : ret;
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}
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static const struct serdev_device_ops snd_serial_generic_serdev_device_ops = {
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.receive_buf = snd_serial_generic_receive_buf,
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.write_wakeup = snd_serial_generic_write_wakeup
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};
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static int snd_serial_generic_ensure_serdev_open(struct snd_serial_generic *drvdata)
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{
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int err;
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unsigned int actual_baud;
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if (drvdata->filemode)
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return 0;
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dev_dbg(drvdata->card->dev, "Opening serial port for card %s\n",
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drvdata->card->shortname);
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err = serdev_device_open(drvdata->serdev);
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if (err < 0)
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return err;
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actual_baud = serdev_device_set_baudrate(drvdata->serdev,
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drvdata->baudrate);
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if (actual_baud != drvdata->baudrate) {
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dev_warn(drvdata->card->dev, "requested %d baud for card %s but it was actually set to %d\n",
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drvdata->baudrate, drvdata->card->shortname, actual_baud);
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}
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return 0;
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}
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static int snd_serial_generic_input_open(struct snd_rawmidi_substream *substream)
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{
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int err;
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struct snd_serial_generic *drvdata = substream->rmidi->card->private_data;
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dev_dbg(drvdata->card->dev, "Opening input for card %s\n",
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drvdata->card->shortname);
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err = snd_serial_generic_ensure_serdev_open(drvdata);
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if (err < 0)
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return err;
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set_bit(SERIAL_MODE_INPUT_OPEN, &drvdata->filemode);
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drvdata->midi_input = substream;
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return 0;
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}
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static int snd_serial_generic_input_close(struct snd_rawmidi_substream *substream)
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{
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struct snd_serial_generic *drvdata = substream->rmidi->card->private_data;
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dev_dbg(drvdata->card->dev, "Closing input for card %s\n",
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drvdata->card->shortname);
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clear_bit(SERIAL_MODE_INPUT_OPEN, &drvdata->filemode);
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clear_bit(SERIAL_MODE_INPUT_TRIGGERED, &drvdata->filemode);
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drvdata->midi_input = NULL;
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if (!drvdata->filemode)
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serdev_device_close(drvdata->serdev);
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return 0;
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}
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static void snd_serial_generic_input_trigger(struct snd_rawmidi_substream *substream,
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int up)
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{
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struct snd_serial_generic *drvdata = substream->rmidi->card->private_data;
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if (up)
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set_bit(SERIAL_MODE_INPUT_TRIGGERED, &drvdata->filemode);
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else
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clear_bit(SERIAL_MODE_INPUT_TRIGGERED, &drvdata->filemode);
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}
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static int snd_serial_generic_output_open(struct snd_rawmidi_substream *substream)
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{
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struct snd_serial_generic *drvdata = substream->rmidi->card->private_data;
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int err;
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dev_dbg(drvdata->card->dev, "Opening output for card %s\n",
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drvdata->card->shortname);
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err = snd_serial_generic_ensure_serdev_open(drvdata);
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if (err < 0)
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return err;
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set_bit(SERIAL_MODE_OUTPUT_OPEN, &drvdata->filemode);
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drvdata->midi_output = substream;
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return 0;
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};
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static int snd_serial_generic_output_close(struct snd_rawmidi_substream *substream)
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{
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struct snd_serial_generic *drvdata = substream->rmidi->card->private_data;
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dev_dbg(drvdata->card->dev, "Closing output for card %s\n",
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drvdata->card->shortname);
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clear_bit(SERIAL_MODE_OUTPUT_OPEN, &drvdata->filemode);
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clear_bit(SERIAL_MODE_OUTPUT_TRIGGERED, &drvdata->filemode);
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if (!drvdata->filemode)
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serdev_device_close(drvdata->serdev);
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drvdata->midi_output = NULL;
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return 0;
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};
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static void snd_serial_generic_output_trigger(struct snd_rawmidi_substream *substream,
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int up)
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{
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struct snd_serial_generic *drvdata = substream->rmidi->card->private_data;
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if (up)
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set_bit(SERIAL_MODE_OUTPUT_TRIGGERED, &drvdata->filemode);
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else
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clear_bit(SERIAL_MODE_OUTPUT_TRIGGERED, &drvdata->filemode);
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if (up)
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snd_serial_generic_tx_wakeup(drvdata);
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}
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static void snd_serial_generic_output_drain(struct snd_rawmidi_substream *substream)
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{
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struct snd_serial_generic *drvdata = substream->rmidi->card->private_data;
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/* Flush any pending characters */
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serdev_device_write_flush(drvdata->serdev);
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cancel_work_sync(&drvdata->tx_work);
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}
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static const struct snd_rawmidi_ops snd_serial_generic_output = {
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.open = snd_serial_generic_output_open,
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.close = snd_serial_generic_output_close,
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.trigger = snd_serial_generic_output_trigger,
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.drain = snd_serial_generic_output_drain,
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};
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static const struct snd_rawmidi_ops snd_serial_generic_input = {
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.open = snd_serial_generic_input_open,
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.close = snd_serial_generic_input_close,
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.trigger = snd_serial_generic_input_trigger,
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};
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static void snd_serial_generic_parse_dt(struct serdev_device *serdev,
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struct snd_serial_generic *drvdata)
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{
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int err;
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err = of_property_read_u32(serdev->dev.of_node, "current-speed",
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&drvdata->baudrate);
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if (err < 0) {
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dev_dbg(drvdata->card->dev,
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"MIDI device reading of current-speed DT param failed with error %d, using default of 38400\n",
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err);
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drvdata->baudrate = 38400;
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}
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}
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static void snd_serial_generic_substreams(struct snd_rawmidi_str *stream, int dev_num)
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{
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struct snd_rawmidi_substream *substream;
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list_for_each_entry(substream, &stream->substreams, list) {
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sprintf(substream->name, "Serial MIDI %d-%d", dev_num, substream->number);
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}
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}
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static int snd_serial_generic_rmidi(struct snd_serial_generic *drvdata,
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int outs, int ins, struct snd_rawmidi **rmidi)
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{
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struct snd_rawmidi *rrawmidi;
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int err;
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err = snd_rawmidi_new(drvdata->card, drvdata->card->driver, 0,
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outs, ins, &rrawmidi);
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if (err < 0)
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return err;
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snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_INPUT,
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&snd_serial_generic_input);
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snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
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&snd_serial_generic_output);
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strcpy(rrawmidi->name, drvdata->card->shortname);
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snd_serial_generic_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT],
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drvdata->serdev->ctrl->nr);
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snd_serial_generic_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT],
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drvdata->serdev->ctrl->nr);
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rrawmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
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SNDRV_RAWMIDI_INFO_INPUT |
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SNDRV_RAWMIDI_INFO_DUPLEX;
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if (rmidi)
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*rmidi = rrawmidi;
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return 0;
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}
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static int snd_serial_generic_probe(struct serdev_device *serdev)
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{
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struct snd_card *card;
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struct snd_serial_generic *drvdata;
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int err;
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err = snd_devm_card_new(&serdev->dev, SNDRV_DEFAULT_IDX1,
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SNDRV_DEFAULT_STR1, THIS_MODULE,
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sizeof(struct snd_serial_generic), &card);
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if (err < 0)
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return err;
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strcpy(card->driver, "SerialMIDI");
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sprintf(card->shortname, "SerialMIDI-%d", serdev->ctrl->nr);
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sprintf(card->longname, "Serial MIDI device at serial%d", serdev->ctrl->nr);
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drvdata = card->private_data;
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drvdata->serdev = serdev;
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drvdata->card = card;
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snd_serial_generic_parse_dt(serdev, drvdata);
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INIT_WORK(&drvdata->tx_work, snd_serial_generic_tx_work);
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err = snd_serial_generic_rmidi(drvdata, 1, 1, &drvdata->rmidi);
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if (err < 0)
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return err;
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serdev_device_set_client_ops(serdev, &snd_serial_generic_serdev_device_ops);
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serdev_device_set_drvdata(drvdata->serdev, drvdata);
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err = snd_card_register(card);
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if (err < 0)
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return err;
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return 0;
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}
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static const struct of_device_id snd_serial_generic_dt_ids[] = {
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{ .compatible = "serial-midi" },
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{},
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};
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MODULE_DEVICE_TABLE(of, snd_serial_generic_dt_ids);
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static struct serdev_device_driver snd_serial_generic_driver = {
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.driver = {
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.name = "snd-serial-generic",
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.of_match_table = of_match_ptr(snd_serial_generic_dt_ids),
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},
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.probe = snd_serial_generic_probe,
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};
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module_serdev_device_driver(snd_serial_generic_driver);
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