On Tue, Jul 30, 2019 at 01:09:36PM +0100, Thomas Preston wrote:
> Add an I2C based codec driver for ST TDA7802 amplifier. The amplifier
> supports 4 audio channels but can support up to 16 with multiple
> devices.
>
> Signed-off-by: Thomas Preston <[email protected]>
> Cc: Patrick Glaser <[email protected]>
> Cc: Rob Duncan <[email protected]>
> Cc: Nate Case <[email protected]>
> ---
> Changes since v1:
> - Use ALSA kcontrol interface to expose device controls to userland
> - Gain
> - Channel diagnostic mode
> - Impedance efficiency optimiser. I decided against setting this
> as a DT property since it seems like something that can be
> changed on the fly.
> - Add regmap default values
> - Channel unmute by default is added in a downstream patch.
> - I'm not sure if I should keep this since they're all zero,
> although there are other drivers will all-zero reg_defaults.
> - I believe the "//" style is used for SPDX headers in normal C source files.
> https://lwn.net/Articles/739183/
> - Drop the "enable" sysfs device attribute.
> - Don't set TDM format using magic numbers.
> - Set sample rate using hw_params.
> - Remove unecessary defines.
> - Use DAPM to handle AMP_ON.
> - Cosmetic fixups
>
> sound/soc/codecs/Kconfig | 6 +
> sound/soc/codecs/Makefile | 2 +
> sound/soc/codecs/tda7802.c | 509 +++++++++++++++++++++++++++++++++++++
> 3 files changed, 517 insertions(+)
> create mode 100644 sound/soc/codecs/tda7802.c
>
> +++ b/sound/soc/codecs/tda7802.c
> @@ -0,0 +1,509 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * tda7802.c -- codec driver for ST TDA7802
> + *
> + * Copyright (C) 2016-2019 Tesla Motors, Inc.
> + */
Better to make the whole comment // see something like
sound/soc/codecs/cs47l35.c for an example.
> +static int tda7802_set_bias_level(struct snd_soc_component *component,
> + enum snd_soc_bias_level level)
> +{
> + const struct tda7802_priv *tda7802 =
> + snd_soc_component_get_drvdata(component);
> + struct snd_soc_dapm_context *dapm_context =
> + snd_soc_component_get_dapm(component);
> + const enum snd_soc_bias_level oldlevel =
> + snd_soc_dapm_get_bias_level(dapm_context);
> + int err = 0;
> +
> + dev_dbg(component->dev, "%s level %d\n", __func__, level);
> +
> + switch (level) {
> + case SND_SOC_BIAS_ON:
> + break;
> + case SND_SOC_BIAS_PREPARE:
> + break;
> + case SND_SOC_BIAS_STANDBY:
> + err = regulator_enable(tda7802->enable_reg);
> + if (err < 0) {
> + dev_err(component->dev, "Could not enable.\n");
> + return err;
> + }
> + dev_dbg(component->dev, "Regulator enabled\n");
> + msleep(ENABLE_DELAY_MS);
> +
> + if (oldlevel == SND_SOC_BIAS_OFF) {
> + dev_dbg(component->dev, "Syncing regcache\n");
> + err = regcache_sync(component->regmap);
> + if (err < 0)
> + dev_err(component->dev,
> + "Could not sync regcache, %d\n", err);
If your doing a regcache_sync I would probably have expected to
see calls to regcache_cache_only.
If the device needs syncing that implies the hardware registers
have lost state, so there is little point in writing to them
if they are unavailable/about to loose their state.
> + }
> + break;
> + case SND_SOC_BIAS_OFF:
> + regcache_mark_dirty(component->regmap);
> + err = regulator_disable(tda7802->enable_reg);
> + if (err < 0)
> + dev_err(component->dev, "Could not disable.\n");
> + break;
> + }
> +
> + return err;
> +}
Thanks,
Charles
