goldfish: audio support
authorAlan Cox <alan@linux.intel.com>
Wed, 23 Jan 2013 14:13:52 +0000 (14:13 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 24 Jan 2013 21:51:38 +0000 (13:51 -0800)
(remove change to another file that escaped into the patch set)

From: Mike Lockwood <lockwood@google.com>

Provide a simple audio channel between the kernel and the emulator that host
sit. Queued for staging right now as this ought to be an ALSA driver not
just a dumb device of its own making.

Signed-off-by: Mike A. Chan <mikechan@google.com>
[x86 support]
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Signed-off-by: Xiaohui Xin <xiaohui.xin@intel.com>
Signed-off-by: Jun Nakajima <jun.nakajima@intel.com>
Signed-off-by: Bruce Beare <bruce.j.beare@intel.com>
[Clean up]
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/staging/Kconfig
drivers/staging/Makefile
drivers/staging/goldfish/Kconfig [new file with mode: 0644]
drivers/staging/goldfish/Makefile [new file with mode: 0644]
drivers/staging/goldfish/README [new file with mode: 0644]
drivers/staging/goldfish/goldfish_audio.c [new file with mode: 0644]

index 0b47a06..3a7965d 100644 (file)
@@ -140,4 +140,6 @@ source "drivers/staging/fwserial/Kconfig"
 
 source "drivers/staging/zcache/Kconfig"
 
+source "drivers/staging/goldfish/Kconfig"
+
 endif # STAGING
index b026ea3..5971865 100644 (file)
@@ -62,3 +62,4 @@ obj-$(CONFIG_DGRP)            += dgrp/
 obj-$(CONFIG_SB105X)           += sb105x/
 obj-$(CONFIG_FIREWIRE_SERIAL)  += fwserial/
 obj-$(CONFIG_ZCACHE)           += zcache/
+obj-$(CONFIG_GOLDFISH)         += goldfish/
diff --git a/drivers/staging/goldfish/Kconfig b/drivers/staging/goldfish/Kconfig
new file mode 100644 (file)
index 0000000..1a3e576
--- /dev/null
@@ -0,0 +1,6 @@
+config GOLDFISH_AUDIO
+       tristate "Goldfish AVD Audio Device"
+       depends on GOLDFISH
+       ---help---
+         Emulated audio channel for the Goldfish Android Virtual Device
+
diff --git a/drivers/staging/goldfish/Makefile b/drivers/staging/goldfish/Makefile
new file mode 100644 (file)
index 0000000..054eeb8
--- /dev/null
@@ -0,0 +1,5 @@
+#
+# Makefile for the Goldfish audio driver
+#
+
+obj-$(CONFIG_GOLDFISH_AUDIO) += goldfish_audio.o
diff --git a/drivers/staging/goldfish/README b/drivers/staging/goldfish/README
new file mode 100644 (file)
index 0000000..afa69bd
--- /dev/null
@@ -0,0 +1,2 @@
+- Move to using the ALSA framework not faking it
+- Fix the wrong user page DMA (moving to ALSA may fix that too)
diff --git a/drivers/staging/goldfish/goldfish_audio.c b/drivers/staging/goldfish/goldfish_audio.c
new file mode 100644 (file)
index 0000000..d3bed21
--- /dev/null
@@ -0,0 +1,363 @@
+/* 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>
+
+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;
+       spinlock_t lock;
+       wait_queue_head_t wait;
+
+       char __iomem *buffer_virt;      /* combined buffer virtual address */
+       unsigned long buffer_phys;      /* combined buffer physical address */
+
+       char __iomem *write_buffer1;    /* write buffer 1 virtual address */
+       char __iomem *write_buffer2;    /* write buffer 2 virtual address */
+       char __iomem *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))
+
+/* 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,
+
+       /* true if audio input is supported */
+       AUDIO_READ_SUPPORTED = 0x18,
+       /* buffer to use for audio input */
+       AUDIO_SET_READ_BUFFER = 0x1C,
+
+       /* 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 __iomem *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;
+       } else {
+               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;
+       else
+               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 = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (data == NULL) {
+               ret = -ENOMEM;
+               goto err_data_alloc_failed;
+       }
+       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 == NULL) {
+               dev_err(&pdev->dev, "platform_get_resource failed\n");
+               ret = -ENODEV;
+               goto err_no_io_base;
+       }
+       data->reg_base = ioremap(r->start, PAGE_SIZE);
+       if (data->reg_base == NULL) {
+               ret = -ENOMEM;
+               goto err_no_io_base;
+       }
+
+       data->irq = platform_get_irq(pdev, 0);
+       if (data->irq < 0) {
+               dev_err(&pdev->dev, "platform_get_irq failed\n");
+               ret = -ENODEV;
+               goto err_no_irq;
+       }
+       data->buffer_virt = dma_alloc_coherent(&pdev->dev,
+                               COMBINED_BUFFER_SIZE, &buf_addr, GFP_KERNEL);
+       if (data->buffer_virt == 0) {
+               ret = -ENOMEM;
+               dev_err(&pdev->dev, "allocate buffer failed\n");
+               goto err_alloc_write_buffer_failed;
+       }
+       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 = request_irq(data->irq, goldfish_audio_interrupt,
+                                       IRQF_SHARED, pdev->name, data);
+       if (ret) {
+               dev_err(&pdev->dev, "request_irq failed\n");
+               goto err_request_irq_failed;
+       }
+
+       ret = misc_register(&goldfish_audio_device);
+       if (ret) {
+               dev_err(&pdev->dev,
+                       "misc_register returned %d in goldfish_audio_init\n",
+                                                               ret);
+               goto err_misc_register_failed;
+       }
+
+       AUDIO_WRITE(data, AUDIO_SET_WRITE_BUFFER_1, buf_addr);
+       AUDIO_WRITE(data, AUDIO_SET_WRITE_BUFFER_2,
+                                               buf_addr + WRITE_BUFFER_SIZE);
+
+       data->read_supported = AUDIO_READ(data, AUDIO_READ_SUPPORTED);
+       if (data->read_supported)
+               AUDIO_WRITE(data, AUDIO_SET_READ_BUFFER,
+                                       buf_addr + 2 * WRITE_BUFFER_SIZE);
+
+       audio_data = data;
+       return 0;
+
+err_misc_register_failed:
+err_request_irq_failed:
+       dma_free_coherent(&pdev->dev, COMBINED_BUFFER_SIZE,
+                                       data->buffer_virt, data->buffer_phys);
+err_alloc_write_buffer_failed:
+err_no_irq:
+       iounmap(data->reg_base);
+err_no_io_base:
+       kfree(data);
+err_data_alloc_failed:
+       return ret;
+}
+
+static int goldfish_audio_remove(struct platform_device *pdev)
+{
+       struct goldfish_audio *data = platform_get_drvdata(pdev);
+
+       misc_deregister(&goldfish_audio_device);
+       free_irq(data->irq, data);
+       dma_free_coherent(&pdev->dev, COMBINED_BUFFER_SIZE,
+                                       data->buffer_virt, data->buffer_phys);
+       iounmap(data->reg_base);
+       kfree(data);
+       audio_data = NULL;
+       return 0;
+}
+
+static struct platform_driver goldfish_audio_driver = {
+       .probe          = goldfish_audio_probe,
+       .remove         = goldfish_audio_remove,
+       .driver = {
+               .name = "goldfish_audio"
+       }
+};
+
+module_platform_driver(goldfish_audio_driver);