+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0
-/*
- * drivers/misc/goldfish_audio.c
- *
- * Copyright (C) 2007 Google, Inc.
- * Copyright (C) 2012 Intel, Inc.
- */
-
-#include <linux/module.h>
-#include <linux/miscdevice.h>
-#include <linux/fs.h>
-#include <linux/platform_device.h>
-#include <linux/types.h>
-#include <linux/pci.h>
-#include <linux/interrupt.h>
-#include <linux/io.h>
-#include <linux/sched.h>
-#include <linux/dma-mapping.h>
-#include <linux/uaccess.h>
-#include <linux/slab.h>
-#include <linux/goldfish.h>
-#include <linux/acpi.h>
-
-MODULE_AUTHOR("Google, Inc.");
-MODULE_DESCRIPTION("Android QEMU Audio Driver");
-MODULE_LICENSE("GPL");
-MODULE_VERSION("1.0");
-
-struct goldfish_audio {
- char __iomem *reg_base;
- int irq;
-
- /* lock protects access to buffer_status and to device registers */
- spinlock_t lock;
- wait_queue_head_t wait;
-
- char *buffer_virt; /* combined buffer virtual address */
- unsigned long buffer_phys; /* combined buffer physical address */
-
- char *write_buffer1; /* write buffer 1 virtual address */
- char *write_buffer2; /* write buffer 2 virtual address */
- char *read_buffer; /* read buffer virtual address */
- int buffer_status;
- int read_supported; /* true if we have audio input support */
-};
-
-/*
- * We will allocate two read buffers and two write buffers.
- * Having two read buffers facilitate stereo -> mono conversion.
- * Having two write buffers facilitate interleaved IO.
- */
-#define READ_BUFFER_SIZE 16384
-#define WRITE_BUFFER_SIZE 16384
-#define COMBINED_BUFFER_SIZE ((2 * READ_BUFFER_SIZE) + \
- (2 * WRITE_BUFFER_SIZE))
-
-/*
- * temporary variable used between goldfish_audio_probe() and
- * goldfish_audio_open()
- */
-static struct goldfish_audio *audio_data;
-
-enum {
- /* audio status register */
- AUDIO_INT_STATUS = 0x00,
- /* set this to enable IRQ */
- AUDIO_INT_ENABLE = 0x04,
- /* set these to specify buffer addresses */
- AUDIO_SET_WRITE_BUFFER_1 = 0x08,
- AUDIO_SET_WRITE_BUFFER_2 = 0x0C,
- /* set number of bytes in buffer to write */
- AUDIO_WRITE_BUFFER_1 = 0x10,
- AUDIO_WRITE_BUFFER_2 = 0x14,
- AUDIO_SET_WRITE_BUFFER_1_HIGH = 0x28,
- AUDIO_SET_WRITE_BUFFER_2_HIGH = 0x30,
-
- /* true if audio input is supported */
- AUDIO_READ_SUPPORTED = 0x18,
- /* buffer to use for audio input */
- AUDIO_SET_READ_BUFFER = 0x1C,
- AUDIO_SET_READ_BUFFER_HIGH = 0x34,
-
- /* driver writes number of bytes to read */
- AUDIO_START_READ = 0x20,
-
- /* number of bytes available in read buffer */
- AUDIO_READ_BUFFER_AVAILABLE = 0x24,
-
- /* AUDIO_INT_STATUS bits */
-
- /* this bit set when it is safe to write more bytes to the buffer */
- AUDIO_INT_WRITE_BUFFER_1_EMPTY = 1U << 0,
- AUDIO_INT_WRITE_BUFFER_2_EMPTY = 1U << 1,
- AUDIO_INT_READ_BUFFER_FULL = 1U << 2,
-
- AUDIO_INT_MASK = AUDIO_INT_WRITE_BUFFER_1_EMPTY |
- AUDIO_INT_WRITE_BUFFER_2_EMPTY |
- AUDIO_INT_READ_BUFFER_FULL,
-};
-
-static atomic_t open_count = ATOMIC_INIT(0);
-
-static unsigned int audio_read(const struct goldfish_audio *data, int addr)
-{
- return readl(data->reg_base + addr);
-}
-
-static void audio_write(const struct goldfish_audio *data,
- int addr, unsigned int x)
-{
- writel(x, data->reg_base + addr);
-}
-
-static void audio_write64(const struct goldfish_audio *data,
- int addr_lo, int addr_hi, unsigned int x)
-{
- char __iomem *reg_base = data->reg_base;
-
- gf_write_dma_addr(x, reg_base + addr_lo, reg_base + addr_hi);
-}
-
-static ssize_t goldfish_audio_read(struct file *fp, char __user *buf,
- size_t count, loff_t *pos)
-{
- struct goldfish_audio *data = fp->private_data;
- unsigned long irq_flags;
- int length;
- int result = 0;
-
- if (!data->read_supported)
- return -ENODEV;
-
- while (count > 0) {
- length = (count > READ_BUFFER_SIZE ? READ_BUFFER_SIZE : count);
- audio_write(data, AUDIO_START_READ, length);
-
- wait_event_interruptible(data->wait, data->buffer_status &
- AUDIO_INT_READ_BUFFER_FULL);
-
- spin_lock_irqsave(&data->lock, irq_flags);
- data->buffer_status &= ~AUDIO_INT_READ_BUFFER_FULL;
- spin_unlock_irqrestore(&data->lock, irq_flags);
-
- length = audio_read(data, AUDIO_READ_BUFFER_AVAILABLE);
-
- /* copy data to user space */
- if (copy_to_user(buf, data->read_buffer, length))
- return -EFAULT;
-
- result += length;
- buf += length;
- count -= length;
- }
- return result;
-}
-
-static ssize_t goldfish_audio_write(struct file *fp, const char __user *buf,
- size_t count, loff_t *pos)
-{
- struct goldfish_audio *data = fp->private_data;
- unsigned long irq_flags;
- ssize_t result = 0;
- char *kbuf;
-
- while (count > 0) {
- ssize_t copy = count;
-
- if (copy > WRITE_BUFFER_SIZE)
- copy = WRITE_BUFFER_SIZE;
- wait_event_interruptible(data->wait, data->buffer_status &
- (AUDIO_INT_WRITE_BUFFER_1_EMPTY |
- AUDIO_INT_WRITE_BUFFER_2_EMPTY));
-
- if ((data->buffer_status & AUDIO_INT_WRITE_BUFFER_1_EMPTY) != 0)
- kbuf = data->write_buffer1;
- else
- kbuf = data->write_buffer2;
-
- /* copy from user space to the appropriate buffer */
- if (copy_from_user(kbuf, buf, copy)) {
- result = -EFAULT;
- break;
- }
-
- spin_lock_irqsave(&data->lock, irq_flags);
- /*
- * clear the buffer empty flag, and signal the emulator
- * to start writing the buffer
- */
- if (kbuf == data->write_buffer1) {
- data->buffer_status &= ~AUDIO_INT_WRITE_BUFFER_1_EMPTY;
- audio_write(data, AUDIO_WRITE_BUFFER_1, copy);
- } else {
- data->buffer_status &= ~AUDIO_INT_WRITE_BUFFER_2_EMPTY;
- audio_write(data, AUDIO_WRITE_BUFFER_2, copy);
- }
- spin_unlock_irqrestore(&data->lock, irq_flags);
-
- buf += copy;
- result += copy;
- count -= copy;
- }
- return result;
-}
-
-static int goldfish_audio_open(struct inode *ip, struct file *fp)
-{
- if (!audio_data)
- return -ENODEV;
-
- if (atomic_inc_return(&open_count) == 1) {
- fp->private_data = audio_data;
- audio_data->buffer_status = (AUDIO_INT_WRITE_BUFFER_1_EMPTY |
- AUDIO_INT_WRITE_BUFFER_2_EMPTY);
- audio_write(audio_data, AUDIO_INT_ENABLE, AUDIO_INT_MASK);
- return 0;
- }
-
- atomic_dec(&open_count);
- return -EBUSY;
-}
-
-static int goldfish_audio_release(struct inode *ip, struct file *fp)
-{
- atomic_dec(&open_count);
- /* FIXME: surely this is wrong for the multi-opened case */
- audio_write(audio_data, AUDIO_INT_ENABLE, 0);
- return 0;
-}
-
-static long goldfish_audio_ioctl(struct file *fp, unsigned int cmd,
- unsigned long arg)
-{
- /* temporary workaround, until we switch to the ALSA API */
- if (cmd == 315)
- return -1;
-
- return 0;
-}
-
-static irqreturn_t goldfish_audio_interrupt(int irq, void *dev_id)
-{
- unsigned long irq_flags;
- struct goldfish_audio *data = dev_id;
- u32 status;
-
- spin_lock_irqsave(&data->lock, irq_flags);
-
- /* read buffer status flags */
- status = audio_read(data, AUDIO_INT_STATUS);
- status &= AUDIO_INT_MASK;
- /*
- * if buffers are newly empty, wake up blocked
- * goldfish_audio_write() call
- */
- if (status) {
- data->buffer_status = status;
- wake_up(&data->wait);
- }
-
- spin_unlock_irqrestore(&data->lock, irq_flags);
- return status ? IRQ_HANDLED : IRQ_NONE;
-}
-
-/* file operations for /dev/eac */
-static const struct file_operations goldfish_audio_fops = {
- .owner = THIS_MODULE,
- .read = goldfish_audio_read,
- .write = goldfish_audio_write,
- .open = goldfish_audio_open,
- .release = goldfish_audio_release,
- .unlocked_ioctl = goldfish_audio_ioctl,
-};
-
-static struct miscdevice goldfish_audio_device = {
- .minor = MISC_DYNAMIC_MINOR,
- .name = "eac",
- .fops = &goldfish_audio_fops,
-};
-
-static int goldfish_audio_probe(struct platform_device *pdev)
-{
- int ret;
- struct resource *r;
- struct goldfish_audio *data;
- dma_addr_t buf_addr;
-
- data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
- if (!data)
- return -ENOMEM;
- spin_lock_init(&data->lock);
- init_waitqueue_head(&data->wait);
- platform_set_drvdata(pdev, data);
-
- r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!r) {
- dev_err(&pdev->dev, "platform_get_resource failed\n");
- return -ENODEV;
- }
- data->reg_base = devm_ioremap(&pdev->dev, r->start, PAGE_SIZE);
- if (!data->reg_base)
- return -ENOMEM;
-
- data->irq = platform_get_irq(pdev, 0);
- if (data->irq < 0)
- return -ENODEV;
- data->buffer_virt = dmam_alloc_coherent(&pdev->dev,
- COMBINED_BUFFER_SIZE,
- &buf_addr, GFP_KERNEL);
- if (!data->buffer_virt) {
- dev_err(&pdev->dev, "allocate buffer failed\n");
- return -ENOMEM;
- }
- data->buffer_phys = buf_addr;
- data->write_buffer1 = data->buffer_virt;
- data->write_buffer2 = data->buffer_virt + WRITE_BUFFER_SIZE;
- data->read_buffer = data->buffer_virt + 2 * WRITE_BUFFER_SIZE;
-
- ret = devm_request_irq(&pdev->dev, data->irq, goldfish_audio_interrupt,
- IRQF_SHARED, pdev->name, data);
- if (ret) {
- dev_err(&pdev->dev, "request_irq failed\n");
- return ret;
- }
-
- ret = misc_register(&goldfish_audio_device);
- if (ret) {
- dev_err(&pdev->dev,
- "misc_register returned %d in goldfish_audio_init\n",
- ret);
- return ret;
- }
-
- audio_write64(data, AUDIO_SET_WRITE_BUFFER_1,
- AUDIO_SET_WRITE_BUFFER_1_HIGH, buf_addr);
- buf_addr += WRITE_BUFFER_SIZE;
-
- audio_write64(data, AUDIO_SET_WRITE_BUFFER_2,
- AUDIO_SET_WRITE_BUFFER_2_HIGH, buf_addr);
-
- buf_addr += WRITE_BUFFER_SIZE;
-
- data->read_supported = audio_read(data, AUDIO_READ_SUPPORTED);
- if (data->read_supported)
- audio_write64(data, AUDIO_SET_READ_BUFFER,
- AUDIO_SET_READ_BUFFER_HIGH, buf_addr);
-
- audio_data = data;
- return 0;
-}
-
-static int goldfish_audio_remove(struct platform_device *pdev)
-{
- misc_deregister(&goldfish_audio_device);
- audio_data = NULL;
- return 0;
-}
-
-static const struct of_device_id goldfish_audio_of_match[] = {
- { .compatible = "google,goldfish-audio", },
- {},
-};
-MODULE_DEVICE_TABLE(of, goldfish_audio_of_match);
-
-#ifdef CONFIG_ACPI
-static const struct acpi_device_id goldfish_audio_acpi_match[] = {
- { "GFSH0005", 0 },
- { },
-};
-MODULE_DEVICE_TABLE(acpi, goldfish_audio_acpi_match);
-#endif
-
-static struct platform_driver goldfish_audio_driver = {
- .probe = goldfish_audio_probe,
- .remove = goldfish_audio_remove,
- .driver = {
- .name = "goldfish_audio",
- .of_match_table = goldfish_audio_of_match,
- .acpi_match_table = ACPI_PTR(goldfish_audio_acpi_match),
- }
-};
-
-module_platform_driver(goldfish_audio_driver);
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