target/linux/goldfish/patches-2.6.30/0120--ARM-goldfish-Add-audio-driver-for-goldfish.patch

   1 From aefe5257bf3ed9bf950ad962a63e5315566c2f97 Mon Sep 17 00:00:00 2001
   2 From: Mike Lockwood <lockwood@google.com>
   3 Date: Mon, 23 Jul 2007 09:31:54 -0400
   4 Subject: [PATCH 120/134] [ARM] goldfish: Add audio driver for goldfish.
   5
   6 Signed-off-by: Mike A. Chan <mikechan@google.com>
   7 ---
   8  arch/arm/mach-goldfish/Makefile |    2 +-
   9  arch/arm/mach-goldfish/audio.c  |  379 +++++++++++++++++++++++++++++++++++++++
  10  2 files changed, 380 insertions(+), 1 deletions(-)
  11  create mode 100644 arch/arm/mach-goldfish/audio.c
  12
  13 --- a/arch/arm/mach-goldfish/Makefile
  14 +++ b/arch/arm/mach-goldfish/Makefile
  15 @@ -4,6 +4,6 @@
  16
  17  # Object file lists.
  18
  19 -obj-y                          := pdev_bus.o timer.o
  20 +obj-y                          := pdev_bus.o timer.o audio.o
  21  obj-$(CONFIG_MACH_GOLDFISH)    += board-goldfish.o
  22
  23 --- /dev/null
  24 +++ b/arch/arm/mach-goldfish/audio.c
  25 @@ -0,0 +1,379 @@
  26 +/* arch/arm/mach-goldfish/audio.c
  27 +**
  28 +** Copyright (C) 2007 Google, Inc.
  29 +**
  30 +** This software is licensed under the terms of the GNU General Public
  31 +** License version 2, as published by the Free Software Foundation, and
  32 +** may be copied, distributed, and modified under those terms.
  33 +**
  34 +** This program is distributed in the hope that it will be useful,
  35 +** but WITHOUT ANY WARRANTY; without even the implied warranty of
  36 +** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  37 +** GNU General Public License for more details.
  38 +**
  39 +*/
  40 +
  41 +#include <linux/module.h>
  42 +#include <linux/miscdevice.h>
  43 +#include <linux/fs.h>
  44 +#include <linux/platform_device.h>
  45 +
  46 +#include <linux/types.h>
  47 +#include <linux/pci.h>
  48 +#include <linux/interrupt.h>
  49 +
  50 +#include <asm/types.h>
  51 +#include <asm/io.h>
  52 +#include <asm/uaccess.h>
  53 +
  54 +
  55 +MODULE_AUTHOR("Google, Inc.");
  56 +MODULE_DESCRIPTION("Android QEMU Audio Driver");
  57 +MODULE_LICENSE("GPL");
  58 +MODULE_VERSION("1.0");
  59 +
  60 +struct goldfish_audio {
  61 +       uint32_t reg_base;
  62 +       int irq;
  63 +       spinlock_t lock;
  64 +       wait_queue_head_t wait;
  65 +
  66 +       char __iomem *buffer_virt;      /* combined buffer virtual address */
  67 +       unsigned long buffer_phys;      /* combined buffer physical address */
  68 +
  69 +       char __iomem *write_buffer1;    /* write buffer 1 virtual address */
  70 +       char __iomem *write_buffer2;    /* write buffer 2 virtual address */
  71 +       char __iomem *read_buffer;      /* read buffer virtual address */
  72 +       int buffer_status;
  73 +       int read_supported;         /* true if we have audio input support */
  74 +};
  75 +
  76 +/* We will allocate two read buffers and two write buffers.
  77 +   Having two read buffers facilitate stereo -> mono conversion.
  78 +   Having two write buffers facilitate interleaved IO.
  79 +*/
  80 +#define READ_BUFFER_SIZE        16384
  81 +#define WRITE_BUFFER_SIZE       16384
  82 +#define COMBINED_BUFFER_SIZE    ((2 * READ_BUFFER_SIZE) + (2 * WRITE_BUFFER_SIZE))
  83 +
  84 +#define GOLDFISH_AUDIO_READ(data, addr)   (readl(data->reg_base + addr))
  85 +#define GOLDFISH_AUDIO_WRITE(data, addr, x)   (writel(x, data->reg_base + addr))
  86 +
  87 +/* temporary variable used between goldfish_audio_probe() and goldfish_audio_open() */
  88 +static struct goldfish_audio* audio_data;
  89 +
  90 +enum {
  91 +       /* audio status register */
  92 +       AUDIO_INT_STATUS        = 0x00,
  93 +       /* set this to enable IRQ */
  94 +       AUDIO_INT_ENABLE        = 0x04,
  95 +       /* set these to specify buffer addresses */
  96 +       AUDIO_SET_WRITE_BUFFER_1 = 0x08,
  97 +       AUDIO_SET_WRITE_BUFFER_2 = 0x0C,
  98 +       /* set number of bytes in buffer to write */
  99 +       AUDIO_WRITE_BUFFER_1  = 0x10,
 100 +       AUDIO_WRITE_BUFFER_2  = 0x14,
 101 +
 102 +       /* true if audio input is supported */
 103 +       AUDIO_READ_SUPPORTED = 0x18,
 104 +       /* buffer to use for audio input */
 105 +       AUDIO_SET_READ_BUFFER = 0x1C,
 106 +
 107 +       /* driver writes number of bytes to read */
 108 +       AUDIO_START_READ  = 0x20,
 109 +
 110 +       /* number of bytes available in read buffer */
 111 +       AUDIO_READ_BUFFER_AVAILABLE  = 0x24,
 112 +
 113 +       /* AUDIO_INT_STATUS bits */
 114 +
 115 +       /* this bit set when it is safe to write more bytes to the buffer */
 116 +       AUDIO_INT_WRITE_BUFFER_1_EMPTY  = 1U << 0,
 117 +       AUDIO_INT_WRITE_BUFFER_2_EMPTY  = 1U << 1,
 118 +       AUDIO_INT_READ_BUFFER_FULL      = 1U << 2,
 119 +
 120 +       AUDIO_INT_MASK                  = AUDIO_INT_WRITE_BUFFER_1_EMPTY |
 121 +                                         AUDIO_INT_WRITE_BUFFER_2_EMPTY |
 122 +                                         AUDIO_INT_READ_BUFFER_FULL,
 123 +};
 124 +
 125 +
 126 +static atomic_t open_count = ATOMIC_INIT(0);
 127 +
 128 +
 129 +static ssize_t goldfish_audio_read(struct file *fp, char __user *buf,
 130 +                                                       size_t count, loff_t *pos)
 131 +{
 132 +       struct goldfish_audio* data = fp->private_data;
 133 +       int length;
 134 +       int result = 0;
 135 +
 136 +       if (!data->read_supported)
 137 +               return -ENODEV;
 138 +
 139 +       while (count > 0) {
 140 +               length = (count > READ_BUFFER_SIZE ? READ_BUFFER_SIZE : count);
 141 +               GOLDFISH_AUDIO_WRITE(data, AUDIO_START_READ, length);
 142 +
 143 +               wait_event_interruptible(data->wait, (data->buffer_status & AUDIO_INT_READ_BUFFER_FULL));
 144 +
 145 +               length = GOLDFISH_AUDIO_READ(data, AUDIO_READ_BUFFER_AVAILABLE);
 146 +
 147 +               /* copy data to user space */
 148 +               if (copy_to_user(buf, data->read_buffer, length))
 149 +               {
 150 +                       printk("copy_from_user failed!\n");
 151 +                       return -EFAULT;
 152 +               }
 153 +
 154 +               result += length;
 155 +               buf += length;
 156 +               count -= length;
 157 +       }
 158 +
 159 +       return result;
 160 +}
 161 +
 162 +static ssize_t goldfish_audio_write(struct file *fp, const char __user *buf,
 163 +                                                        size_t count, loff_t *pos)
 164 +{
 165 +       struct goldfish_audio* data = fp->private_data;
 166 +       unsigned long irq_flags;
 167 +       ssize_t result = 0;
 168 +       char __iomem *kbuf;
 169 +
 170 +       while (count > 0)
 171 +       {
 172 +               ssize_t copy = count;
 173 +               if (copy > WRITE_BUFFER_SIZE)
 174 +                       copy = WRITE_BUFFER_SIZE;
 175 +               wait_event_interruptible(data->wait,
 176 +                               (data->buffer_status & (AUDIO_INT_WRITE_BUFFER_1_EMPTY | AUDIO_INT_WRITE_BUFFER_2_EMPTY)));
 177 +
 178 +               if ((data->buffer_status & AUDIO_INT_WRITE_BUFFER_1_EMPTY) != 0) {
 179 +                       kbuf = data->write_buffer1;
 180 +               } else {
 181 +                       kbuf = data->write_buffer2;
 182 +               }
 183 +
 184 +               /* copy from user space to the appropriate buffer */
 185 +               if (copy_from_user(kbuf, buf, copy))
 186 +               {
 187 +                       printk("copy_from_user failed!\n");
 188 +                       result = -EFAULT;
 189 +                       break;
 190 +               }
 191 +               else
 192 +               {
 193 +                       spin_lock_irqsave(&data->lock, irq_flags);
 194 +
 195 +                       /* clear the buffer empty flag, and signal the emulator to start writing the buffer */
 196 +                       if (kbuf == data->write_buffer1) {
 197 +                               data->buffer_status &= ~AUDIO_INT_WRITE_BUFFER_1_EMPTY;
 198 +                               GOLDFISH_AUDIO_WRITE(data, AUDIO_WRITE_BUFFER_1, copy);
 199 +                       } else {
 200 +                               data->buffer_status &= ~AUDIO_INT_WRITE_BUFFER_2_EMPTY;
 201 +                               GOLDFISH_AUDIO_WRITE(data, AUDIO_WRITE_BUFFER_2, copy);
 202 +                       }
 203 +
 204 +                       spin_unlock_irqrestore(&data->lock, irq_flags);
 205 +               }
 206 +
 207 +               buf += copy;
 208 +               result += copy;
 209 +               count -= copy;
 210 +       }
 211 +
 212 +       return result;
 213 +}
 214 +
 215 +static int goldfish_audio_open(struct inode *ip, struct file *fp)
 216 +{
 217 +       if (!audio_data)
 218 +               return -ENODEV;
 219 +
 220 +       if (atomic_inc_return(&open_count) == 1)
 221 +       {
 222 +               fp->private_data = audio_data;
 223 +               audio_data->buffer_status = (AUDIO_INT_WRITE_BUFFER_1_EMPTY | AUDIO_INT_WRITE_BUFFER_2_EMPTY);
 224 +               GOLDFISH_AUDIO_WRITE(audio_data, AUDIO_INT_ENABLE, AUDIO_INT_MASK);
 225 +               return 0;
 226 +       }
 227 +       else
 228 +       {
 229 +               atomic_dec(&open_count);
 230 +               return -EBUSY;
 231 +       }
 232 +}
 233 +
 234 +static int goldfish_audio_release(struct inode *ip, struct file* fp)
 235 +{
 236 +       atomic_dec(&open_count);
 237 +       GOLDFISH_AUDIO_WRITE(audio_data, AUDIO_INT_ENABLE, 0);
 238 +       return 0;
 239 +}
 240 +
 241 +static int goldfish_audio_ioctl(struct inode* ip, struct file* fp, unsigned int cmd, unsigned long arg)
 242 +{
 243 +       /* temporary workaround, until we switch to the ALSA API */
 244 +       if (cmd == 315)
 245 +               return -1;
 246 +       else
 247 +               return 0;
 248 +}
 249 +
 250 +static irqreturn_t
 251 +goldfish_audio_interrupt(int irq, void *dev_id)
 252 +{
 253 +       unsigned long irq_flags;
 254 +       struct goldfish_audio   *data = dev_id;
 255 +       uint32_t status;
 256 +
 257 +       spin_lock_irqsave(&data->lock, irq_flags);
 258 +
 259 +       /* read buffer status flags */
 260 +       status = GOLDFISH_AUDIO_READ(data, AUDIO_INT_STATUS);
 261 +       status &= AUDIO_INT_MASK;
 262 +       /* if buffers are newly empty, wake up blocked goldfish_audio_write() call */
 263 +       if(status) {
 264 +               data->buffer_status = status;
 265 +               wake_up(&data->wait);
 266 +       }
 267 +
 268 +       spin_unlock_irqrestore(&data->lock, irq_flags);
 269 +       return status ? IRQ_HANDLED : IRQ_NONE;
 270 +}
 271 +
 272 +/* file operations for /dev/eac */
 273 +static struct file_operations goldfish_audio_fops = {
 274 +       .owner = THIS_MODULE,
 275 +       .read = goldfish_audio_read,
 276 +       .write = goldfish_audio_write,
 277 +       .open = goldfish_audio_open,
 278 +       .release = goldfish_audio_release,
 279 +   .ioctl = goldfish_audio_ioctl,
 280 +
 281 +};
 282 +
 283 +static struct miscdevice goldfish_audio_device = {
 284 +       .minor = MISC_DYNAMIC_MINOR,
 285 +       .name = "eac",
 286 +       .fops = &goldfish_audio_fops,
 287 +};
 288 +
 289 +static int goldfish_audio_probe(struct platform_device *pdev)
 290 +{
 291 +       int ret;
 292 +       struct resource *r;
 293 +       struct goldfish_audio *data;
 294 +       dma_addr_t buf_addr;
 295 +
 296 +printk("goldfish_audio_probe\n");
 297 +       data = kzalloc(sizeof(*data), GFP_KERNEL);
 298 +       if(data == NULL) {
 299 +               ret = -ENOMEM;
 300 +               goto err_data_alloc_failed;
 301 +       }
 302 +       spin_lock_init(&data->lock);
 303 +       init_waitqueue_head(&data->wait);
 304 +       platform_set_drvdata(pdev, data);
 305 +
 306 +       r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 307 +       if(r == NULL) {
 308 +               printk("platform_get_resource failed\n");
 309 +               ret = -ENODEV;
 310 +               goto err_no_io_base;
 311 +       }
 312 +       data->reg_base = IO_ADDRESS(r->start - IO_START);
 313 +
 314 +       data->irq = platform_get_irq(pdev, 0);
 315 +       if(data->irq < 0) {
 316 +               printk("platform_get_irq failed\n");
 317 +               ret = -ENODEV;
 318 +               goto err_no_irq;
 319 +       }
 320 +
 321 +       data->buffer_virt = dma_alloc_writecombine(&pdev->dev, COMBINED_BUFFER_SIZE,
 322 +                                                                                               &buf_addr, GFP_KERNEL);
 323 +       if(data->buffer_virt == 0) {
 324 +               ret = -ENOMEM;
 325 +               goto err_alloc_write_buffer_failed;
 326 +       }
 327 +       data->buffer_phys = buf_addr;
 328 +       data->write_buffer1 = data->buffer_virt;
 329 +       data->write_buffer2 = data->buffer_virt + WRITE_BUFFER_SIZE;
 330 +       data->read_buffer = data->buffer_virt + 2 * WRITE_BUFFER_SIZE;
 331 +
 332 +       ret = request_irq(data->irq, goldfish_audio_interrupt, IRQF_SHARED, pdev->name, data);
 333 +       if(ret)
 334 +               goto err_request_irq_failed;
 335 +
 336 +       if((ret = misc_register(&goldfish_audio_device)))
 337 +       {
 338 +               printk("misc_register returned %d in goldfish_audio_init\n", ret);
 339 +               goto err_misc_register_failed;
 340 +       }
 341 +
 342 +
 343 +       GOLDFISH_AUDIO_WRITE(data, AUDIO_SET_WRITE_BUFFER_1, buf_addr);
 344 +       GOLDFISH_AUDIO_WRITE(data, AUDIO_SET_WRITE_BUFFER_2, buf_addr + WRITE_BUFFER_SIZE);
 345 +
 346 +       data->read_supported = GOLDFISH_AUDIO_READ(data, AUDIO_READ_SUPPORTED);
 347 +       if (data->read_supported)
 348 +               GOLDFISH_AUDIO_WRITE(data, AUDIO_SET_READ_BUFFER, buf_addr + 2 * WRITE_BUFFER_SIZE);
 349 +
 350 +       audio_data = data;
 351 +       return 0;
 352 +
 353 +err_misc_register_failed:
 354 +err_request_irq_failed:
 355 +       dma_free_writecombine(&pdev->dev, COMBINED_BUFFER_SIZE, data->buffer_virt, data->buffer_phys);
 356 +err_alloc_write_buffer_failed:
 357 +err_no_irq:
 358 +err_no_io_base:
 359 +       kfree(data);
 360 +err_data_alloc_failed:
 361 +       return ret;
 362 +}
 363 +
 364 +static int goldfish_audio_remove(struct platform_device *pdev)
 365 +{
 366 +       struct goldfish_audio *data = platform_get_drvdata(pdev);
 367 +
 368 +       misc_deregister(&goldfish_audio_device);
 369 +       free_irq(data->irq, data);
 370 +       dma_free_writecombine(&pdev->dev, COMBINED_BUFFER_SIZE, data->buffer_virt, data->buffer_phys);
 371 +       kfree(data);
 372 +       audio_data = NULL;
 373 +       return 0;
 374 +}
 375 +
 376 +static struct platform_driver goldfish_audio_driver = {
 377 +       .probe          = goldfish_audio_probe,
 378 +       .remove         = goldfish_audio_remove,
 379 +       .driver = {
 380 +               .name = "goldfish_audio"
 381 +       }
 382 +};
 383 +
 384 +static int __init goldfish_audio_init(void)
 385 +{
 386 +       int ret;
 387 +
 388 +       ret = platform_driver_register(&goldfish_audio_driver);
 389 +       if (ret < 0)
 390 +       {
 391 +               printk("platform_driver_register returned %d\n", ret);
 392 +               return ret;
 393 +       }
 394 +
 395 +       return ret;
 396 +}
 397 +
 398 +static void __exit goldfish_audio_exit(void)
 399 +{
 400 +       platform_driver_unregister(&goldfish_audio_driver);
 401 +}
 402 +
 403 +module_init(goldfish_audio_init);
 404 +module_exit(goldfish_audio_exit);