ASoC: Allow setting codec register with debugfs filesystem

i.e. echo 6 59 >/sys/kernel/debug/soc-audio.0/codec_reg
will set register 0x06 to a value of 0x59.
Also, pop_time debugfs interface setup is moved so that it
is setup in the same function as codec_reg

Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 113 insertions, 3 deletions

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 462e635dfc74..4707042b3dad 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -26,6 +26,7 @@
 #include <linux/delay.h>
 #include <linux/pm.h>
 #include <linux/bitops.h>
+#include <linux/debugfs.h>
 #include <linux/platform_device.h>
 #include <sound/core.h>
 #include <sound/pcm.h>
@@ -961,10 +962,8 @@ static int soc_new_pcm(struct snd_soc_device *socdev,
 }
 
 /* codec register dump */
-static ssize_t codec_reg_show(struct device *dev,
-        struct device_attribute *attr, char *buf)
+static ssize_t soc_codec_reg_show(struct snd_soc_device *devdata, char *buf)
 {
-        struct snd_soc_device *devdata = dev_get_drvdata(dev);
         struct snd_soc_codec *codec = devdata->codec;
         int i, step = 1, count = 0;
 
@@ -1001,8 +1000,117 @@ static ssize_t codec_reg_show(struct device *dev,
 
         return count;
 }
+static ssize_t codec_reg_show(struct device *dev,
+        struct device_attribute *attr, char *buf)
+{
+        struct snd_soc_device *devdata = dev_get_drvdata(dev);
+        return soc_codec_reg_show(devdata, buf);
+}
+
 static DEVICE_ATTR(codec_reg, 0444, codec_reg_show, NULL);
 
+#ifdef CONFIG_DEBUG_FS
+static int codec_reg_open_file(struct inode *inode, struct file *file)
+{
+        file->private_data = inode->i_private;
+        return 0;
+}
+
+static ssize_t codec_reg_read_file(struct file *file, char __user *user_buf,
+                               size_t count, loff_t *ppos)
+{
+        ssize_t ret;
+        struct snd_soc_device *devdata = file->private_data;
+        char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+        if (!buf)
+                return -ENOMEM;
+        ret = soc_codec_reg_show(devdata, buf);
+        if (ret >= 0)
+                ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
+        kfree(buf);
+        return ret;
+}
+
+static ssize_t codec_reg_write_file(struct file *file,
+                const char __user *user_buf, size_t count, loff_t *ppos)
+{
+        char buf[32];
+        int buf_size;
+        char *start = buf;
+        unsigned long reg, value;
+        int step = 1;
+        struct snd_soc_device *devdata = file->private_data;
+        struct snd_soc_codec *codec = devdata->codec;
+
+        buf_size = min(count, (sizeof(buf)-1));
+        if (copy_from_user(buf, user_buf, buf_size))
+                return -EFAULT;
+        buf[buf_size] = 0;
+
+        if (codec->reg_cache_step)
+                step = codec->reg_cache_step;
+
+        while (*start == ' ')
+                start++;
+        reg = simple_strtoul(start, &start, 16);
+        if ((reg >= codec->reg_cache_size) || (reg % step))
+                return -EINVAL;
+        while (*start == ' ')
+                start++;
+        if (strict_strtoul(start, 16, &value))
+                return -EINVAL;
+        codec->write(codec, reg, value);
+        return buf_size;
+}
+
+static const struct file_operations codec_reg_fops = {
+        .open = codec_reg_open_file,
+        .read = codec_reg_read_file,
+        .write = codec_reg_write_file,
+};
+
+static void soc_init_debugfs(struct snd_soc_device *socdev)
+{
+        struct dentry *root, *file;
+        struct snd_soc_codec *codec = socdev->codec;
+        root = debugfs_create_dir(dev_name(socdev->dev), NULL);
+        if (IS_ERR(root) || !root)
+                goto exit1;
+
+        file = debugfs_create_file("codec_reg", 0644,
+                        root, socdev, &codec_reg_fops);
+        if (!file)
+                goto exit2;
+
+        file = debugfs_create_u32("dapm_pop_time", 0744,
+                        root, &codec->pop_time);
+        if (!file)
+                goto exit2;
+        socdev->debugfs_root = root;
+        return;
+exit2:
+        debugfs_remove_recursive(root);
+exit1:
+        dev_err(socdev->dev, "debugfs is not available\n");
+}
+
+static void soc_cleanup_debugfs(struct snd_soc_device *socdev)
+{
+        debugfs_remove_recursive(socdev->debugfs_root);
+        socdev->debugfs_root = NULL;
+}
+
+#else
+
+static inline void soc_init_debugfs(struct snd_soc_device *socdev)
+{
+}
+
+static inline void soc_cleanup_debugfs(struct snd_soc_device *socdev)
+{
+}
+#endif
+
 /**
  * snd_soc_new_ac97_codec - initailise AC97 device
  * @codec: audio codec
@@ -1216,6 +1324,7 @@ int snd_soc_register_card(struct snd_soc_device *socdev)
         if (err < 0)
                 printk(KERN_WARNING "asoc: failed to add codec sysfs files\n");
 
+        soc_init_debugfs(socdev);
         mutex_unlock(&codec->mutex);
 
 out:
@@ -1239,6 +1348,7 @@ void snd_soc_free_pcms(struct snd_soc_device *socdev)
 #endif
 
         mutex_lock(&codec->mutex);
+        soc_cleanup_debugfs(socdev);
 #ifdef CONFIG_SND_SOC_AC97_BUS
         for (i = 0; i < codec->num_dai; i++) {
                 codec_dai = &codec->dai[i];