diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /sound/drivers/serial-generic.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'sound/drivers/serial-generic.c')
| -rw-r--r-- | sound/drivers/serial-generic.c | 376 |
1 files changed, 376 insertions, 0 deletions
diff --git a/sound/drivers/serial-generic.c b/sound/drivers/serial-generic.c new file mode 100644 index 000000000..766206c6c --- /dev/null +++ b/sound/drivers/serial-generic.c @@ -0,0 +1,376 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * serial-generic.c + * Copyright (c) by Daniel Kaehn <kaehndan@gmail.com + * Based on serial-u16550.c by Jaroslav Kysela <perex@perex.cz>, + * Isaku Yamahata <yamahata@private.email.ne.jp>, + * George Hansper <ghansper@apana.org.au>, + * Hannu Savolainen + * + * Generic serial MIDI driver using the serdev serial bus API for hardware interaction + */ + +#include <linux/err.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/ioport.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/serdev.h> +#include <linux/serial_reg.h> +#include <linux/slab.h> +#include <linux/dev_printk.h> + +#include <sound/core.h> +#include <sound/rawmidi.h> +#include <sound/initval.h> + +MODULE_DESCRIPTION("Generic serial MIDI driver"); +MODULE_LICENSE("GPL"); + +#define SERIAL_MODE_INPUT_OPEN 1 +#define SERIAL_MODE_OUTPUT_OPEN 2 +#define SERIAL_MODE_INPUT_TRIGGERED 3 +#define SERIAL_MODE_OUTPUT_TRIGGERED 4 + +#define SERIAL_TX_STATE_ACTIVE 1 +#define SERIAL_TX_STATE_WAKEUP 2 + +#define INTERNAL_BUF_SIZE 256 + +struct snd_serial_generic { + struct serdev_device *serdev; + + struct snd_card *card; + struct snd_rawmidi *rmidi; + struct snd_rawmidi_substream *midi_output; + struct snd_rawmidi_substream *midi_input; + + unsigned int baudrate; + + unsigned long filemode; /* open status of file */ + struct work_struct tx_work; + unsigned long tx_state; + + char tx_buf[INTERNAL_BUF_SIZE]; +}; + +static void snd_serial_generic_tx_wakeup(struct snd_serial_generic *drvdata) +{ + if (test_and_set_bit(SERIAL_TX_STATE_ACTIVE, &drvdata->tx_state)) + set_bit(SERIAL_TX_STATE_WAKEUP, &drvdata->tx_state); + + schedule_work(&drvdata->tx_work); +} + +static void snd_serial_generic_tx_work(struct work_struct *work) +{ + int num_bytes; + struct snd_serial_generic *drvdata = container_of(work, struct snd_serial_generic, + tx_work); + struct snd_rawmidi_substream *substream = drvdata->midi_output; + + clear_bit(SERIAL_TX_STATE_WAKEUP, &drvdata->tx_state); + + while (!snd_rawmidi_transmit_empty(substream)) { + + if (!test_bit(SERIAL_MODE_OUTPUT_OPEN, &drvdata->filemode)) + break; + + num_bytes = snd_rawmidi_transmit_peek(substream, drvdata->tx_buf, + INTERNAL_BUF_SIZE); + num_bytes = serdev_device_write_buf(drvdata->serdev, drvdata->tx_buf, + num_bytes); + + if (!num_bytes) + break; + + snd_rawmidi_transmit_ack(substream, num_bytes); + + if (!test_bit(SERIAL_TX_STATE_WAKEUP, &drvdata->tx_state)) + break; + } + + clear_bit(SERIAL_TX_STATE_ACTIVE, &drvdata->tx_state); +} + +static void snd_serial_generic_write_wakeup(struct serdev_device *serdev) +{ + struct snd_serial_generic *drvdata = serdev_device_get_drvdata(serdev); + + snd_serial_generic_tx_wakeup(drvdata); +} + +static size_t snd_serial_generic_receive_buf(struct serdev_device *serdev, + const u8 *buf, size_t count) +{ + int ret; + struct snd_serial_generic *drvdata = serdev_device_get_drvdata(serdev); + + if (!test_bit(SERIAL_MODE_INPUT_OPEN, &drvdata->filemode)) + return 0; + + ret = snd_rawmidi_receive(drvdata->midi_input, buf, count); + return ret < 0 ? 0 : ret; +} + +static const struct serdev_device_ops snd_serial_generic_serdev_device_ops = { + .receive_buf = snd_serial_generic_receive_buf, + .write_wakeup = snd_serial_generic_write_wakeup +}; + +static int snd_serial_generic_ensure_serdev_open(struct snd_serial_generic *drvdata) +{ + int err; + unsigned int actual_baud; + + if (drvdata->filemode) + return 0; + + dev_dbg(drvdata->card->dev, "Opening serial port for card %s\n", + drvdata->card->shortname); + err = serdev_device_open(drvdata->serdev); + if (err < 0) + return err; + + actual_baud = serdev_device_set_baudrate(drvdata->serdev, + drvdata->baudrate); + if (actual_baud != drvdata->baudrate) { + dev_warn(drvdata->card->dev, "requested %d baud for card %s but it was actually set to %d\n", + drvdata->baudrate, drvdata->card->shortname, actual_baud); + } + + return 0; +} + +static int snd_serial_generic_input_open(struct snd_rawmidi_substream *substream) +{ + int err; + struct snd_serial_generic *drvdata = substream->rmidi->card->private_data; + + dev_dbg(drvdata->card->dev, "Opening input for card %s\n", + drvdata->card->shortname); + + err = snd_serial_generic_ensure_serdev_open(drvdata); + if (err < 0) + return err; + + set_bit(SERIAL_MODE_INPUT_OPEN, &drvdata->filemode); + drvdata->midi_input = substream; + return 0; +} + +static int snd_serial_generic_input_close(struct snd_rawmidi_substream *substream) +{ + struct snd_serial_generic *drvdata = substream->rmidi->card->private_data; + + dev_dbg(drvdata->card->dev, "Closing input for card %s\n", + drvdata->card->shortname); + + clear_bit(SERIAL_MODE_INPUT_OPEN, &drvdata->filemode); + clear_bit(SERIAL_MODE_INPUT_TRIGGERED, &drvdata->filemode); + + drvdata->midi_input = NULL; + + if (!drvdata->filemode) + serdev_device_close(drvdata->serdev); + return 0; +} + +static void snd_serial_generic_input_trigger(struct snd_rawmidi_substream *substream, + int up) +{ + struct snd_serial_generic *drvdata = substream->rmidi->card->private_data; + + if (up) + set_bit(SERIAL_MODE_INPUT_TRIGGERED, &drvdata->filemode); + else + clear_bit(SERIAL_MODE_INPUT_TRIGGERED, &drvdata->filemode); +} + +static int snd_serial_generic_output_open(struct snd_rawmidi_substream *substream) +{ + struct snd_serial_generic *drvdata = substream->rmidi->card->private_data; + int err; + + dev_dbg(drvdata->card->dev, "Opening output for card %s\n", + drvdata->card->shortname); + + err = snd_serial_generic_ensure_serdev_open(drvdata); + if (err < 0) + return err; + + set_bit(SERIAL_MODE_OUTPUT_OPEN, &drvdata->filemode); + + drvdata->midi_output = substream; + return 0; +}; + +static int snd_serial_generic_output_close(struct snd_rawmidi_substream *substream) +{ + struct snd_serial_generic *drvdata = substream->rmidi->card->private_data; + + dev_dbg(drvdata->card->dev, "Closing output for card %s\n", + drvdata->card->shortname); + + clear_bit(SERIAL_MODE_OUTPUT_OPEN, &drvdata->filemode); + clear_bit(SERIAL_MODE_OUTPUT_TRIGGERED, &drvdata->filemode); + + if (!drvdata->filemode) + serdev_device_close(drvdata->serdev); + + drvdata->midi_output = NULL; + + return 0; +}; + +static void snd_serial_generic_output_trigger(struct snd_rawmidi_substream *substream, + int up) +{ + struct snd_serial_generic *drvdata = substream->rmidi->card->private_data; + + if (up) + set_bit(SERIAL_MODE_OUTPUT_TRIGGERED, &drvdata->filemode); + else + clear_bit(SERIAL_MODE_OUTPUT_TRIGGERED, &drvdata->filemode); + + if (up) + snd_serial_generic_tx_wakeup(drvdata); +} + +static void snd_serial_generic_output_drain(struct snd_rawmidi_substream *substream) +{ + struct snd_serial_generic *drvdata = substream->rmidi->card->private_data; + + /* Flush any pending characters */ + serdev_device_write_flush(drvdata->serdev); + cancel_work_sync(&drvdata->tx_work); +} + +static const struct snd_rawmidi_ops snd_serial_generic_output = { + .open = snd_serial_generic_output_open, + .close = snd_serial_generic_output_close, + .trigger = snd_serial_generic_output_trigger, + .drain = snd_serial_generic_output_drain, +}; + +static const struct snd_rawmidi_ops snd_serial_generic_input = { + .open = snd_serial_generic_input_open, + .close = snd_serial_generic_input_close, + .trigger = snd_serial_generic_input_trigger, +}; + +static void snd_serial_generic_parse_dt(struct serdev_device *serdev, + struct snd_serial_generic *drvdata) +{ + int err; + + err = of_property_read_u32(serdev->dev.of_node, "current-speed", + &drvdata->baudrate); + if (err < 0) { + dev_dbg(drvdata->card->dev, + "MIDI device reading of current-speed DT param failed with error %d, using default of 38400\n", + err); + drvdata->baudrate = 38400; + } + +} + +static void snd_serial_generic_substreams(struct snd_rawmidi_str *stream, int dev_num) +{ + struct snd_rawmidi_substream *substream; + + list_for_each_entry(substream, &stream->substreams, list) { + sprintf(substream->name, "Serial MIDI %d-%d", dev_num, substream->number); + } +} + +static int snd_serial_generic_rmidi(struct snd_serial_generic *drvdata, + int outs, int ins, struct snd_rawmidi **rmidi) +{ + struct snd_rawmidi *rrawmidi; + int err; + + err = snd_rawmidi_new(drvdata->card, drvdata->card->driver, 0, + outs, ins, &rrawmidi); + + if (err < 0) + return err; + + snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_INPUT, + &snd_serial_generic_input); + snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, + &snd_serial_generic_output); + strscpy(rrawmidi->name, drvdata->card->shortname); + + snd_serial_generic_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT], + drvdata->serdev->ctrl->nr); + snd_serial_generic_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT], + drvdata->serdev->ctrl->nr); + + rrawmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT | + SNDRV_RAWMIDI_INFO_INPUT | + SNDRV_RAWMIDI_INFO_DUPLEX; + + if (rmidi) + *rmidi = rrawmidi; + return 0; +} + +static int snd_serial_generic_probe(struct serdev_device *serdev) +{ + struct snd_card *card; + struct snd_serial_generic *drvdata; + int err; + + err = snd_devm_card_new(&serdev->dev, SNDRV_DEFAULT_IDX1, + SNDRV_DEFAULT_STR1, THIS_MODULE, + sizeof(struct snd_serial_generic), &card); + + if (err < 0) + return err; + + strscpy(card->driver, "SerialMIDI"); + sprintf(card->shortname, "SerialMIDI-%d", serdev->ctrl->nr); + sprintf(card->longname, "Serial MIDI device at serial%d", serdev->ctrl->nr); + + drvdata = card->private_data; + + drvdata->serdev = serdev; + drvdata->card = card; + + snd_serial_generic_parse_dt(serdev, drvdata); + + INIT_WORK(&drvdata->tx_work, snd_serial_generic_tx_work); + + err = snd_serial_generic_rmidi(drvdata, 1, 1, &drvdata->rmidi); + if (err < 0) + return err; + + serdev_device_set_client_ops(serdev, &snd_serial_generic_serdev_device_ops); + serdev_device_set_drvdata(drvdata->serdev, drvdata); + + err = snd_card_register(card); + if (err < 0) + return err; + + return 0; +} + +static const struct of_device_id snd_serial_generic_dt_ids[] = { + { .compatible = "serial-midi" }, + {}, +}; + +MODULE_DEVICE_TABLE(of, snd_serial_generic_dt_ids); + +static struct serdev_device_driver snd_serial_generic_driver = { + .driver = { + .name = "snd-serial-generic", + .of_match_table = snd_serial_generic_dt_ids, + }, + .probe = snd_serial_generic_probe, +}; + +module_serdev_device_driver(snd_serial_generic_driver); |
