// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright (c) by Jaroslav Kysela <[email protected]> * Routines for control of MPU-401 in UART mode * * MPU-401 supports UART mode which is not capable generate transmit * interrupts thus output is done via polling. Without interrupt, * input is done also via polling. Do not expect good performance. * * 13-03-2003: * Added support for different kind of hardware I/O. Build in choices * are port and mmio. For other kind of I/O, set mpu->read and * mpu->write to your own I/O functions. */ #include <linux/io.h> #include <linux/delay.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/ioport.h> #include <linux/module.h> #include <linux/interrupt.h> #include <linux/errno.h> #include <sound/core.h> #include <sound/mpu401.h> MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …; static void snd_mpu401_uart_input_read(struct snd_mpu401 * mpu); static void snd_mpu401_uart_output_write(struct snd_mpu401 * mpu); /* */ #define snd_mpu401_input_avail(mpu) … #define snd_mpu401_output_ready(mpu) … /* Build in lowlevel io */ static void mpu401_write_port(struct snd_mpu401 *mpu, unsigned char data, unsigned long addr) { … } static unsigned char mpu401_read_port(struct snd_mpu401 *mpu, unsigned long addr) { … } static void mpu401_write_mmio(struct snd_mpu401 *mpu, unsigned char data, unsigned long addr) { … } static unsigned char mpu401_read_mmio(struct snd_mpu401 *mpu, unsigned long addr) { … } /* */ static void snd_mpu401_uart_clear_rx(struct snd_mpu401 *mpu) { … } static void uart_interrupt_tx(struct snd_mpu401 *mpu) { … } static void _snd_mpu401_uart_interrupt(struct snd_mpu401 *mpu) { … } /** * snd_mpu401_uart_interrupt - generic MPU401-UART interrupt handler * @irq: the irq number * @dev_id: mpu401 instance * * Processes the interrupt for MPU401-UART i/o. * * Return: %IRQ_HANDLED if the interrupt was handled. %IRQ_NONE otherwise. */ irqreturn_t snd_mpu401_uart_interrupt(int irq, void *dev_id) { … } EXPORT_SYMBOL(…); /** * snd_mpu401_uart_interrupt_tx - generic MPU401-UART transmit irq handler * @irq: the irq number * @dev_id: mpu401 instance * * Processes the interrupt for MPU401-UART output. * * Return: %IRQ_HANDLED if the interrupt was handled. %IRQ_NONE otherwise. */ irqreturn_t snd_mpu401_uart_interrupt_tx(int irq, void *dev_id) { … } EXPORT_SYMBOL(…); /* * timer callback * reprogram the timer and call the interrupt job */ static void snd_mpu401_uart_timer(struct timer_list *t) { … } /* * initialize the timer callback if not programmed yet */ static void snd_mpu401_uart_add_timer (struct snd_mpu401 *mpu, int input) { … } /* * remove the timer callback if still active */ static void snd_mpu401_uart_remove_timer (struct snd_mpu401 *mpu, int input) { … } /* * send a UART command * return zero if successful, non-zero for some errors */ static int snd_mpu401_uart_cmd(struct snd_mpu401 * mpu, unsigned char cmd, int ack) { … } static int snd_mpu401_do_reset(struct snd_mpu401 *mpu) { … } /* * input/output open/close - protected by open_mutex in rawmidi.c */ static int snd_mpu401_uart_input_open(struct snd_rawmidi_substream *substream) { … } static int snd_mpu401_uart_output_open(struct snd_rawmidi_substream *substream) { … } static int snd_mpu401_uart_input_close(struct snd_rawmidi_substream *substream) { … } static int snd_mpu401_uart_output_close(struct snd_rawmidi_substream *substream) { … } /* * trigger input callback */ static void snd_mpu401_uart_input_trigger(struct snd_rawmidi_substream *substream, int up) { … } /* * transfer input pending data * call with input_lock spinlock held */ static void snd_mpu401_uart_input_read(struct snd_mpu401 * mpu) { … } /* * Tx FIFO sizes: * CS4237B - 16 bytes * AudioDrive ES1688 - 12 bytes * S3 SonicVibes - 8 bytes * SoundBlaster AWE 64 - 2 bytes (ugly hardware) */ /* * write output pending bytes * call with output_lock spinlock held */ static void snd_mpu401_uart_output_write(struct snd_mpu401 * mpu) { … } /* * output trigger callback */ static void snd_mpu401_uart_output_trigger(struct snd_rawmidi_substream *substream, int up) { … } /* */ static const struct snd_rawmidi_ops snd_mpu401_uart_output = …; static const struct snd_rawmidi_ops snd_mpu401_uart_input = …; static void snd_mpu401_uart_free(struct snd_rawmidi *rmidi) { … } /** * snd_mpu401_uart_new - create an MPU401-UART instance * @card: the card instance * @device: the device index, zero-based * @hardware: the hardware type, MPU401_HW_XXXX * @port: the base address of MPU401 port * @info_flags: bitflags MPU401_INFO_XXX * @irq: the ISA irq number, -1 if not to be allocated * @rrawmidi: the pointer to store the new rawmidi instance * * Creates a new MPU-401 instance. * * Note that the rawmidi instance is returned on the rrawmidi argument, * not the mpu401 instance itself. To access to the mpu401 instance, * cast from rawmidi->private_data (with struct snd_mpu401 magic-cast). * * Return: Zero if successful, or a negative error code. */ int snd_mpu401_uart_new(struct snd_card *card, int device, unsigned short hardware, unsigned long port, unsigned int info_flags, int irq, struct snd_rawmidi ** rrawmidi) { … } EXPORT_SYMBOL(…);
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