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

1From aefe5257bf3ed9bf950ad962a63e5315566c2f97 Mon Sep 17 00:00:00 2001
2From: Mike Lockwood <lockwood@google.com>
3Date: Mon, 23 Jul 2007 09:31:54 -0400
4Subject: [PATCH 120/134] [ARM] goldfish: Add audio driver for goldfish.
5
6Signed-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);
405

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