[PATCH 09/11] ALSA: firewire-motu: add ioctl command to read cached parameters in register DSP model

[Takashi Sakamoto]

This patch adds new ioctl command for userspace applications to read
cached parameters of register DSP.

The structured data includes model-dependent parameters. Userspace
application should be carefully programmed so that what parameter is
common and specific.

Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
---
 include/uapi/sound/firewire.h                 |  1 +
 sound/firewire/motu/motu-hwdep.c              | 21 +++++++++++++++++++
 .../motu/motu-register-dsp-message-parser.c   | 11 ++++++++++
 sound/firewire/motu/motu.h                    |  3 ++-
 4 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/include/uapi/sound/firewire.h b/include/uapi/sound/firewire.h
index 6366127e923e..d52691655d79 100644
--- a/include/uapi/sound/firewire.h
+++ b/include/uapi/sound/firewire.h
@@ -82,6 +82,7 @@ union snd_firewire_event {
 #define SNDRV_FIREWIRE_IOCTL_TASCAM_STATE _IOR('H', 0xfb, struct snd_firewire_tascam_state)
 #define SNDRV_FIREWIRE_IOCTL_MOTU_REGISTER_DSP_METER	_IOR('H', 0xfc, struct snd_firewire_motu_register_dsp_meter)
 #define SNDRV_FIREWIRE_IOCTL_MOTU_COMMAND_DSP_METER	_IOR('H', 0xfd, struct snd_firewire_motu_command_dsp_meter)
+#define SNDRV_FIREWIRE_IOCTL_MOTU_REGISTER_DSP_PARAMETER	_IOR('H', 0xfe, struct snd_firewire_motu_register_dsp_parameter)
 
 #define SNDRV_FIREWIRE_TYPE_DICE	1
 #define SNDRV_FIREWIRE_TYPE_FIREWORKS	2
diff --git a/sound/firewire/motu/motu-hwdep.c b/sound/firewire/motu/motu-hwdep.c
index 7be576fe4516..699136b911c7 100644
--- a/sound/firewire/motu/motu-hwdep.c
+++ b/sound/firewire/motu/motu-hwdep.c
@@ -199,6 +199,27 @@ static int hwdep_ioctl(struct snd_hwdep *hwdep, struct file *file,
 
 		return 0;
 	}
+	case SNDRV_FIREWIRE_IOCTL_MOTU_REGISTER_DSP_PARAMETER:
+	{
+		struct snd_firewire_motu_register_dsp_parameter *param;
+		int err;
+
+		if (!(motu->spec->flags & SND_MOTU_SPEC_REGISTER_DSP))
+			return -ENXIO;
+
+		param = kzalloc(sizeof(*param), GFP_KERNEL);
+		if (!param)
+			return -ENOMEM;
+
+		snd_motu_register_dsp_message_parser_copy_parameter(motu, param);
+
+		err = copy_to_user((void __user *)arg, param, sizeof(*param));
+		kfree(param);
+		if (err)
+			return -EFAULT;
+
+		return 0;
+	}
 	default:
 		return -ENOIOCTLCMD;
 	}
diff --git a/sound/firewire/motu/motu-register-dsp-message-parser.c b/sound/firewire/motu/motu-register-dsp-message-parser.c
index d94ca4875714..ed9fd0cef200 100644
--- a/sound/firewire/motu/motu-register-dsp-message-parser.c
+++ b/sound/firewire/motu/motu-register-dsp-message-parser.c
@@ -299,3 +299,14 @@ void snd_motu_register_dsp_message_parser_copy_meter(struct snd_motu *motu,
 	memcpy(meter, &parser->meter, sizeof(*meter));
 	spin_unlock_irqrestore(&parser->lock, flags);
 }
+
+void snd_motu_register_dsp_message_parser_copy_parameter(struct snd_motu *motu,
+					struct snd_firewire_motu_register_dsp_parameter *param)
+{
+	struct msg_parser *parser = motu->message_parser;
+	unsigned long flags;
+
+	spin_lock_irqsave(&parser->lock, flags);
+	memcpy(param, &parser->param, sizeof(*param));
+	spin_unlock_irqrestore(&parser->lock, flags);
+}
diff --git a/sound/firewire/motu/motu.h b/sound/firewire/motu/motu.h
index 4f70036dea25..fa0b3ab7b78d 100644
--- a/sound/firewire/motu/motu.h
+++ b/sound/firewire/motu/motu.h
@@ -280,7 +280,8 @@ void snd_motu_register_dsp_message_parser_parse(struct snd_motu *motu, const str
 					unsigned int desc_count, unsigned int data_block_quadlets);
 void snd_motu_register_dsp_message_parser_copy_meter(struct snd_motu *motu,
 					struct snd_firewire_motu_register_dsp_meter *meter);
-
+void snd_motu_register_dsp_message_parser_copy_parameter(struct snd_motu *motu,
+					struct snd_firewire_motu_register_dsp_parameter *params);
 
 int snd_motu_command_dsp_message_parser_new(struct snd_motu *motu);
 int snd_motu_command_dsp_message_parser_init(struct snd_motu *motu, enum cip_sfc sfc);
-- 
2.30.2