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Release 4.11 drivers/staging/goldfish/goldfish_audio.c

/*
 * 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; }

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Alan Cox135100.00%1100.00%
Total135100.00%1100.00%


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; }

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Alan Cox21199.53%150.00%
Sara Bird10.47%150.00%
Total212100.00%2100.00%


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; }

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Alan Cox75100.00%1100.00%
Total75100.00%1100.00%


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; }

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Alan Cox35100.00%1100.00%
Total35100.00%1100.00%


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; }

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Alan Cox33100.00%1100.00%
Total33100.00%1100.00%


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; }

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Alan Cox8898.88%150.00%
Sara Bird11.12%150.00%
Total89100.00%2100.00%

/* 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; }

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Alan Cox29776.55%233.33%
Jun Tian5012.89%116.67%
Himangi Saraogi379.54%116.67%
Christian Colic30.77%116.67%
Somya Anand10.26%116.67%
Total388100.00%6100.00%


static int goldfish_audio_remove(struct platform_device *pdev) { misc_deregister(&goldfish_audio_device); audio_data = NULL; return 0; }

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Alan Cox24100.00%1100.00%
Total24100.00%1100.00%

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);

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Alan Cox123789.57%218.18%
Jun Tian624.49%19.09%
Himangi Saraogi372.68%19.09%
Greg Hackmann342.46%218.18%
Sara Bird50.36%19.09%
Christian Colic40.29%218.18%
Loic Pefferkorn10.07%19.09%
Somya Anand10.07%19.09%
Total1381100.00%11100.00%
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