Hello Peter

On 9/20/2012 3:28 PM, Peter Ujfalusi wrote:

On 09/20/2012 10:56 AM, Rajeev kumar wrote:

...

Hello Mark,

We have three volume control in audio codec.

1. Master volume: control both left and right channel volume
2. left volume: control left channel vol
3. right volume: control right channel vol.

So we can provide interfaces for all volume control to the user. Please find below the control I can provide to the user space

case 1:

1. Provide master volume control
2. Provide Left channel volume control.
3. Provide Right channel volume control.

case 2:

1. Provide master volume control
2. Instead of providing separate control for left and right channel,

combined it and provide a single control to user space. so that left and right volume is always in sync.

case 3:

1. Provide master volume control
2. stereo volume control for the left/right channel

You mean to say Left and Right should be a single stereo control which can be provided with SOC_DOUBLE. Actually case 2 corresponds to the same setting which you are suggesting.

But why this is better option?

In case user wants a separate left/right volume control then how this setting is going to help.

Best Rgds ~Rajeev

Hello Peter,

On 9/20/2012 3:49 PM, Peter Ujfalusi wrote:

On 09/20/2012 01:08 PM, Rajeev kumar wrote:

...

...

case 3:

1. Provide master volume control
2. stereo volume control for the left/right channel

You mean to say Left and Right should be a single stereo control which can be provided with SOC_DOUBLE. Actually case 2 corresponds to the same setting which you are suggesting.

But why this is better option?

You have less controls for the codec -> easier for users. Users still can adjust the left/right differently if they want.

...

In case user wants a separate left/right volume control then how this setting is going to help.

In most cases you change both left/right channel: amixer sset 'PCM' 8 # left/right volume is 8

but users can set different volume per channel: amixer sset 'PCM' 8,1 # left volume is 8, right is 1

it is better than: amixer sset 'PCM Left' 8 # left volume is 8 amixer sset 'PCM Right' 8 # left volume is 8

or amixer sset 'PCM Left' 8 # left volume is 8 amixer sset 'PCM Right' 1 # left volume is 1

Thanks for the info.

Please find below the controls I have provided

static const char *pwm_mode_text[] = { "Binary", "Headphone", "Ternary", "Phase-shift"};

static const DECLARE_TLV_DB_SCALE(out_gain_tlv, -9150, 50, 0); static const DECLARE_TLV_DB_SCALE(master_vol_tlv, -12750, 50, 0); static const SOC_ENUM_SINGLE_DECL(pwm_src, STA529_FFXCFG1, 4, pwm_mode_text);

static const struct snd_kcontrol_new sta529_snd_controls[] = { SOC_DOUBLE_R_TLV("Digital Playback Volume", STA529_LVOL, STA529_RVOL, 0, 127, 0, out_gain_tlv), SOC_SINGLE_TLV("Master Playback Volume", STA529_MVOL, 0, 127, 1, master_vol_tlv), SOC_ENUM("PWM Select", pwm_src), };

So in our amixer output I am not getting any separate numid for left/right volume, so that user can control it.

Is there something I am missing in my code.

Best Regards Rajeev