Re: [PATCH v9 3/3] ASoC: qcom: sc7180: Add machine driver for sound card registration

[Stephan Gerhold]

Hi,

Thanks for removing the weird use of auxilliary devices :)

On Fri, Sep 11, 2020 at 06:22:59PM +0800, Cheng-Yi Chiang wrote:
> From: Ajit Pandey <ajitp@xxxxxxxxxxxxxx>
> 
> Add new driver to register sound card on sc7180 trogdor board and
> do the required configuration for lpass cpu dai and external codecs
> connected over MI2S interfaces.
> 
> Signed-off-by: Ajit Pandey <ajitp@xxxxxxxxxxxxxx>
> Signed-off-by: Cheng-Yi Chiang <cychiang@xxxxxxxxxxxx>
> ---
>  sound/soc/qcom/Kconfig  |  12 ++
>  sound/soc/qcom/Makefile |   2 +
>  sound/soc/qcom/sc7180.c | 267 ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 281 insertions(+)
>  create mode 100644 sound/soc/qcom/sc7180.c
> 
> diff --git a/sound/soc/qcom/Kconfig b/sound/soc/qcom/Kconfig
> index a607ace8b089..0459185ee243 100644
> --- a/sound/soc/qcom/Kconfig
> +++ b/sound/soc/qcom/Kconfig
> @@ -116,4 +116,16 @@ config SND_SOC_SDM845
>  	  SDM845 SoC-based systems.
>  	  Say Y if you want to use audio device on this SoCs.
>  
> +config SND_SOC_SC7180
> +	tristate "SoC Machine driver for SC7180 boards"
> +	depends on I2C
> +	select SND_SOC_QCOM_COMMON
> +	select SND_SOC_LPASS_SC7180
> +	select SND_SOC_MAX98357A
> +	select SND_SOC_RT5682_I2C
> +	help
> +	  To add support for audio on Qualcomm Technologies Inc.
> +	  SC7180 SoC-based systems.
> +	  Say Y if you want to use audio device on this SoCs.
> +
>  endif #SND_SOC_QCOM
> diff --git a/sound/soc/qcom/Makefile b/sound/soc/qcom/Makefile
> index 7972c9479ab0..0cdcbf367ef1 100644
> --- a/sound/soc/qcom/Makefile
> +++ b/sound/soc/qcom/Makefile
> @@ -17,12 +17,14 @@ snd-soc-storm-objs := storm.o
>  snd-soc-apq8016-sbc-objs := apq8016_sbc.o
>  snd-soc-apq8096-objs := apq8096.o
>  snd-soc-sdm845-objs := sdm845.o
> +snd-soc-sc7180-objs := sc7180.o
>  snd-soc-qcom-common-objs := common.o
>  
>  obj-$(CONFIG_SND_SOC_STORM) += snd-soc-storm.o
>  obj-$(CONFIG_SND_SOC_APQ8016_SBC) += snd-soc-apq8016-sbc.o
>  obj-$(CONFIG_SND_SOC_MSM8996) += snd-soc-apq8096.o
>  obj-$(CONFIG_SND_SOC_SDM845) += snd-soc-sdm845.o
> +obj-$(CONFIG_SND_SOC_SC7180) += snd-soc-sc7180.o
>  obj-$(CONFIG_SND_SOC_QCOM_COMMON) += snd-soc-qcom-common.o
>  
>  #DSP lib
> diff --git a/sound/soc/qcom/sc7180.c b/sound/soc/qcom/sc7180.c
> new file mode 100644
> index 000000000000..40bc4fc98842
> --- /dev/null
> +++ b/sound/soc/qcom/sc7180.c
> @@ -0,0 +1,267 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +//
> +// Copyright (c) 2020, The Linux Foundation. All rights reserved.
> +//
> +// sc7180.c -- ALSA SoC Machine driver for SC7180
> +
> +#include <dt-bindings/sound/sc7180-lpass.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <sound/core.h>
> +#include <sound/jack.h>
> +#include <sound/pcm.h>
> +#include <sound/pcm_params.h>
> +#include <sound/soc.h>
> +#include <uapi/linux/input-event-codes.h>
> +
> +#include "../codecs/rt5682.h"
> +#include "common.h"
> +#include "lpass.h"
> +
> +#define DEFAULT_SAMPLE_RATE_48K		48000
> +#define DEFAULT_MCLK_RATE		19200000
> +#define RT5682_PLL1_FREQ (48000 * 512)
> +
> +struct sc7180_snd_data {
> +	u32 pri_mi2s_clk_count;
> +	struct snd_soc_jack hs_jack;
> +	struct snd_soc_jack hdmi_jack;
> +};

[...]

> +
> +static const struct snd_soc_ops sc7180_ops = {
> +	.startup = sc7180_snd_startup,
> +	.shutdown = sc7180_snd_shutdown,
> +};
> +
> +static const struct snd_soc_dapm_widget sc7180_snd_widgets[] = {
> +	SND_SOC_DAPM_HP("Headphone Jack", NULL),
> +	SND_SOC_DAPM_MIC("Headset Mic", NULL),
> +};
> +
> +static struct snd_soc_card sc7180_card = {
> +	.owner = THIS_MODULE,
> +	.dapm_widgets = sc7180_snd_widgets,
> +	.num_dapm_widgets = ARRAY_SIZE(sc7180_snd_widgets),
> +};

Given that you modify this struct and already allocate some memory
dynamically (sc7810_snd_data), it might be a bit cleaner to avoid
modifying global memory and instead allocate snd_soc_card dynamically as
well. Could just add it to sc7180_snd_data for example (see e.g. apq8016_sbc)

> +
> +static void sc7180_add_ops(struct snd_soc_card *card)
> +{
> +	struct snd_soc_dai_link *link;
> +	int i;
> +
> +	for_each_card_prelinks(card, i, link) {
> +		link->ops = &sc7180_ops;
> +		link->init = sc7180_init;
> +	}
> +}
> +
> +static int sc7180_snd_platform_probe(struct platform_device *pdev)
> +{
> +	struct snd_soc_card *card = &sc7180_card;
> +	struct sc7180_snd_data *data;
> +	struct device *dev = &pdev->dev;
> +	int ret;
> +
> +	/* Allocate the private data */
> +	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	card->dev = dev;
> +	snd_soc_card_set_drvdata(card, data);
> +
> +	ret = qcom_snd_parse_of(card);
> +	if (ret) {
> +		dev_err(dev, "Error parsing OF data\n");

This will just add noise in case of probe deferral. qcom_snd_parse_of()
already logs a message for most errors so you can just remove this one.

> +		return ret;
> +	}
> +
> +	sc7180_add_ops(card);
> +
> +	return devm_snd_soc_register_card(dev, card);
> +}
> +
> +static const struct of_device_id sc7180_snd_device_id[]  = {
> +	{ .compatible = "qcom,sc7180-sndcard" },

Will all SC7180 use the configuration in this driver? (With RT5682,
HDMI, the jack configuration etc). Otherwise a more specific compatible
string might be better, so other device-specific ones can be added later.

Thanks!
Stephan