| /* |
| * drivers/misc/goldfish_audio.c |
| * |
| * Copyright (C) 2007 Google, Inc. |
| * Copyright (C) 2012 Intel, Inc. |
| * |
| * This software is licensed under the terms of the GNU General Public |
| * License version 2, as published by the Free Software Foundation, and |
| * may be copied, distributed, and modified under those terms. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| */ |
| |
| #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> |
| |
| 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)) |
| |
| #define AUDIO_READ(data, addr) (readl(data->reg_base + addr)) |
| #define AUDIO_WRITE(data, addr, x) (writel(x, data->reg_base + addr)) |
| #define AUDIO_WRITE64(data, addr, addr2, x) \ |
| (gf_write_dma_addr((x), data->reg_base + addr, data->reg_base + addr2)) |
| |
| /* |
| * 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 ssize_t goldfish_audio_read(struct file *fp, char __user *buf, |
| size_t count, loff_t *pos) |
| { |
| struct goldfish_audio *data = fp->private_data; |
| 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); |
| |
| 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) { |
| dev_err(&pdev->dev, "platform_get_irq failed\n"); |
| 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); |
| |
| 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, |
| } |
| }; |
| |
| module_platform_driver(goldfish_audio_driver); |