On 21/02/2020 13:00, Mark Brown wrote:
On Thu, Feb 20, 2020 at 12:04:45PM +0530, Sameer Pujar wrote:
+++ b/sound/soc/tegra/tegra210_dmic.c @@ -0,0 +1,515 @@ +// SPDX-License-Identifier: GPL-2.0-only +/*
- tegra210_dmic.c - Tegra210 DMIC driver
- Copyright (c) 2020 NVIDIA CORPORATION. All rights reserved.
Please make the entire comment a C++ one so things look more intentional.
- /* Below enables all filters - DCR, LP and SC */
- { TEGRA210_DMIC_DBG_CTRL, 0xe },
So this isn't the hardware default?
- srate = params_rate(params);
- if (dmic->srate_override)
srate = dmic->srate_override;How does this work for userspace? If we just ignore the sample rate we were asked for I'd expect that the application would get upset.
Tegra has a hardware sample rate converter (though driver not yet upstream or part of this initial series) and if using the sample-rate converter, then the actual rate captured by the DMIC interface could be different from the resulting sample-rate.
So we want a way to indicate to the DMIC it is capturing at rate X, while the resulting sample-rate is Y.
I am not sure if there is a better way to do this? Ideally, the DMIC would query the rate from the upstream MUX it is connected to, but I am not sure if there is a way to do that. So right now it is a manual process and the user has to configure these which are not ideal.
Cheers Jon