Re: [PATCH] ASoC: Add PCM1681 codec driver.

From: Daniel Mack
Date: Wed Jun 26 2013 - 09:55:31 EST

On 26.06.2013 15:46, Marek Belisko wrote:
> Hi Daniel,
> On 06/26/2013 03:16 PM, Daniel Mack wrote:
>> Hi Marek,
>>
>> On 26.06.2013 15:05, Marek Belisko wrote:
>>> PCM1681 can be controlled via I2C, SPI or in bootstrap mode. This code add
>>> support only for I2C mode.
>>>
>>> Signed-off-by: Marek Belisko <marek.belisko@xxxxxxxxxxxxxxxxxxx>
>>> ---
>>> .../devicetree/bindings/sound/ti,pcm1681.txt | 15 +
>>> sound/soc/codecs/Kconfig | 4 +
>>> sound/soc/codecs/Makefile | 2 +
>>> sound/soc/codecs/pcm1681.c | 328 ++++++++++++++++++++
>>> 4 files changed, 349 insertions(+)
>>> create mode 100644 Documentation/devicetree/bindings/sound/ti,pcm1681.txt
>>> create mode 100644 sound/soc/codecs/pcm1681.c
>>>
>>> diff --git a/Documentation/devicetree/bindings/sound/ti,pcm1681.txt b/Documentation/devicetree/bindings/sound/ti,pcm1681.txt
>>> new file mode 100644
>>> index 0000000..4df1718
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/sound/ti,pcm1681.txt
>>> @@ -0,0 +1,15 @@
>>> +Texas Instruments PCM1681 8-channel PWM Processor
>>> +
>>> +Required properties:
>>> +
>>> + - compatible: Should contain "ti,pcm1681".
>>> + - reg: The i2c address. Should contain <0x4c>.
>>> +
>>> +Examples:
>>> +
>>> + i2c_bus {
>>> + pcm1681@4c {
>>> + compatible = "ti,pcm1681";
>>> + reg = <0x4c>;
>>> + };
>>> + };
>>> diff --git a/sound/soc/codecs/Kconfig b/sound/soc/codecs/Kconfig
>>> index badb6fb..e2daf82 100644
>>> --- a/sound/soc/codecs/Kconfig
>>> +++ b/sound/soc/codecs/Kconfig
>>> @@ -54,6 +54,7 @@ config SND_SOC_ALL_CODECS
>>> select SND_SOC_MC13783 if MFD_MC13XXX
>>> select SND_SOC_ML26124 if I2C
>>> select SND_SOC_HDMI_CODEC
>>> + select SND_SOC_PCM1681 if I2C
>>> select SND_SOC_PCM3008
>>> select SND_SOC_RT5631 if I2C
>>> select SND_SOC_RT5640 if I2C
>>> @@ -292,6 +293,9 @@ config SND_SOC_MAX9850
>>> config SND_SOC_HDMI_CODEC
>>> tristate
>>>
>>> +config SND_SOC_PCM1681
>>> + tristate
>>> +
>>> config SND_SOC_PCM3008
>>> tristate
>>>
>>> diff --git a/sound/soc/codecs/Makefile b/sound/soc/codecs/Makefile
>>> index 70fd806..4a068d2 100644
>>> --- a/sound/soc/codecs/Makefile
>>> +++ b/sound/soc/codecs/Makefile
>>> @@ -42,6 +42,7 @@ snd-soc-max9850-objs := max9850.o
>>> snd-soc-mc13783-objs := mc13783.o
>>> snd-soc-ml26124-objs := ml26124.o
>>> snd-soc-hdmi-codec-objs := hdmi.o
>>> +snd-soc-pcm1681-objs := pcm1681.o
>>> snd-soc-pcm3008-objs := pcm3008.o
>>> snd-soc-rt5631-objs := rt5631.o
>>> snd-soc-rt5640-objs := rt5640.o
>>> @@ -171,6 +172,7 @@ obj-$(CONFIG_SND_SOC_MAX9850) += snd-soc-max9850.o
>>> obj-$(CONFIG_SND_SOC_MC13783) += snd-soc-mc13783.o
>>> obj-$(CONFIG_SND_SOC_ML26124) += snd-soc-ml26124.o
>>> obj-$(CONFIG_SND_SOC_HDMI_CODEC) += snd-soc-hdmi-codec.o
>>> +obj-$(CONFIG_SND_SOC_PCM1681) += snd-soc-pcm1681.o
>>> obj-$(CONFIG_SND_SOC_PCM3008) += snd-soc-pcm3008.o
>>> obj-$(CONFIG_SND_SOC_RT5631) += snd-soc-rt5631.o
>>> obj-$(CONFIG_SND_SOC_RT5640) += snd-soc-rt5640.o
>>> diff --git a/sound/soc/codecs/pcm1681.c b/sound/soc/codecs/pcm1681.c
>>> new file mode 100644
>>> index 0000000..6122fd1
>>> --- /dev/null
>>> +++ b/sound/soc/codecs/pcm1681.c
>>> @@ -0,0 +1,328 @@
>>> +/*
>>> + * PCM1681 ASoC codec driver
>>> + *
>>> + * Copyright (c) StreamUnlimited GmbH 2013
>>> + * Marek Belisko <marek.belisko@xxxxxxxxxxxxxxxxxxx>
>>> + *
>>> + * This program is free software; you can redistribute it and/or
>>> + * modify it under the terms of the GNU General Public License
>>> + * as published by the Free Software Foundation; either version 2
>>> + * of the License, or (at your option) any later version.
>>> + *
>>> + * This program is distributed in the hope that it will be useful,
>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
>>> + * GNU General Public License for more details.
>>> + */
>>> +
>>> +#include <linux/module.h>
>>> +#include <linux/slab.h>
>>> +#include <linux/delay.h>
>>> +#include <linux/gpio.h>
>>> +#include <linux/i2c.h>
>>> +#include <linux/regmap.h>
>>> +#include <linux/of_device.h>
>>> +#include <linux/of_gpio.h>
>>> +#include <sound/pcm.h>
>>> +#include <sound/pcm_params.h>
>>> +#include <sound/soc.h>
>>> +#include <sound/tlv.h>
>>> +
>>> +#define PCM1681_PCM_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | \
>>> + SNDRV_PCM_FMTBIT_S24_LE)
>>> +
>>> +#define PCM1681_PCM_RATES (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000 | \
>>> + SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 | \
>>> + SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_88200 | \
>>> + SNDRV_PCM_RATE_96000 | SNDRV_PCM_RATE_192000)
>>> +
>>> +#define PCM1681_SOFT_MUTE_ALL 0xff
>>> +#define PCM1681_DEEMPH_RATE_MASK 0x18
>>> +#define PCM1681_DEEMPH_MASK 0x01
>>> +
>>> +#define PCM1681_ATT_CONTROL(X) (X <= 6 ? X : X + 9) /* Attenuation level */
>>> +#define PCM1681_SOFT_MUTE 0x07 /* Soft mute control register */
>>> +#define PCM1681_DAC_CONTROL 0x08 /* DAC operation control */
>>> +#define PCM1681_FMT_CONTROL 0x09 /* Audio interface data format */
>>> +#define PCM1681_DEEMPH_CONTROL 0x0a /* De-emphasis control */
>>> +#define PCM1681_ZERO_DETECT_STATUS 0x0e /* Zero detect status reg */
>>> +
>>> +static const struct reg_default pcm1681_reg_defaults[] = {
>>> + { 0x01, 0xff },
>>> + { 0x02, 0xff },
>>> + { 0x03, 0xff },
>>> + { 0x04, 0xff },
>>> + { 0x05, 0xff },
>>> + { 0x06, 0xff },
>>> + { 0x07, 0x00 },
>>> + { 0x08, 0x00 },
>>> + { 0x09, 0x06 },
>>> + { 0x0A, 0x00 },
>>> + { 0x0B, 0xff },
>>> + { 0x0C, 0x0f },
>>> + { 0x0D, 0x00 },
>>> + { 0x10, 0xff },
>>> + { 0x11, 0xff },
>>> + { 0x12, 0x00 },
>>> + { 0x13, 0x00 },
>>> +};
>>> +
>>> +static bool pcm1681_accessible_reg(struct device *dev, unsigned int reg)
>>> +{
>>> + return !((reg == 0x00) || (reg == 0x0f));
>>> +}
>>> +
>>> +static bool pcm1681_writeable_reg(struct device *dev, unsigned register reg)
>>> +{
>>> + return pcm1681_accessible_reg(dev, reg) &&
>>> + (reg != PCM1681_ZERO_DETECT_STATUS);
>>> +}
>>> +
>>> +struct pcm1681_private {
>>> + struct regmap *regmap;
>>> + unsigned int format;
>>> + /* Current deemphasis status */
>>> + unsigned int deemph;
>>> + /* Current rate for deemphasis control */
>>> + unsigned int rate;
>>> +};
>>> +
>>> +static int pcm1681_deemph[] = { 44100, 48000, 32000 };
>>> +
>>> +static int pcm1681_set_deemph(struct snd_soc_codec *codec)
>>> +{
>>> + struct pcm1681_private *priv = snd_soc_codec_get_drvdata(codec);
>>> + int i = 0, val = -1, ret;
>>> +
>>> + if (priv->deemph)
>>> + for (i = 0; i < ARRAY_SIZE(pcm1681_deemph); i++)
>>> + if (pcm1681_deemph[i] == priv->rate)
>>> + val = i;
>>> +
>>> + /* enable choosen frequency */
>>> + if (val != -1)
>>> + regmap_update_bits(priv->regmap, PCM1681_DEEMPH_CONTROL,
>>> + PCM1681_DEEMPH_RATE_MASK, val);
>>> +
>>> + /* enable/disable deemphasis functionality */
>>> + ret = regmap_update_bits(priv->regmap, PCM1681_DEEMPH_CONTROL,
>>> + PCM1681_DEEMPH_MASK, priv->deemph);
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static int pcm1681_get_deemph(struct snd_kcontrol *kcontrol,
>>> + struct snd_ctl_elem_value *ucontrol)
>>> +{
>>> + struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol);
>>> + struct pcm1681_private *priv = snd_soc_codec_get_drvdata(codec);
>>> +
>>> + ucontrol->value.enumerated.item[0] = priv->deemph;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int pcm1681_put_deemph(struct snd_kcontrol *kcontrol,
>>> + struct snd_ctl_elem_value *ucontrol)
>>> +{
>>> + struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol);
>>> + struct pcm1681_private *priv = snd_soc_codec_get_drvdata(codec);
>>> +
>>> + priv->deemph = ucontrol->value.enumerated.item[0];
>>> +
>>> + return pcm1681_set_deemph(codec);
>>> +}
>>> +
>>> +static int pcm1681_set_dai_fmt(struct snd_soc_dai *codec_dai,
>>> + unsigned int format)
>>> +{
>>> + struct snd_soc_codec *codec = codec_dai->codec;
>>> + struct pcm1681_private *priv = snd_soc_codec_get_drvdata(codec);
>>> +
>>> + /* The PCM1681 can only be slave to all clocks */
>>> + if ((format & SND_SOC_DAIFMT_MASTER_MASK) != SND_SOC_DAIFMT_CBS_CFS) {
>>> + dev_err(codec->dev, "Invalid clocking mode\n");
>>> + return -EINVAL;
>>> + }
>>> +
>>> + priv->format = format;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int pcm1681_digital_mute(struct snd_soc_dai *dai, int mute)
>>> +{
>>> + struct snd_soc_codec *codec = dai->codec;
>>> + struct pcm1681_private *priv = snd_soc_codec_get_drvdata(codec);
>>> + int ret, val = 0;
>>> +
>>> + if (mute)
>>> + val = PCM1681_SOFT_MUTE_ALL;
>>> +
>>> + ret = regmap_write(priv->regmap, PCM1681_SOFT_MUTE, val);
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int pcm1681_hw_params(struct snd_pcm_substream *substream,
>>> + struct snd_pcm_hw_params *params,
>>> + struct snd_soc_dai *dai)
>>> +{
>>> + struct snd_soc_codec *codec = dai->codec;
>>> + struct pcm1681_private *priv = snd_soc_codec_get_drvdata(codec);
>>> + int val = 0;
>>> + int pcm_format = params_format(params);
>>> +
>>> + priv->rate = params_rate(params);
>>> +
>>> + switch (priv->format & SND_SOC_DAIFMT_FORMAT_MASK) {
>>> + case SND_SOC_DAIFMT_RIGHT_J:
>>> + if (pcm_format == SNDRV_PCM_FORMAT_S24_LE)
>>> + val = 0x00;
>>> + else if (pcm_format == SNDRV_PCM_FORMAT_S16_LE)
>>> + val = 0x03;
>>> + break;
>>> + case SND_SOC_DAIFMT_I2S:
>>> + val = 0x04;
>>> + break;
>>> + case SND_SOC_DAIFMT_LEFT_J:
>>> + val = 0x05;
>>> + break;
>>> + default:
>>> + dev_err(codec->dev, "Invalid DAI format\n");
>>> + return -EINVAL;
>>> + }
>>> +
>>> + regmap_update_bits(priv->regmap, PCM1681_FMT_CONTROL, 0x0f, val);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static const struct snd_soc_dai_ops pcm1681_dai_ops = {
>>> + .set_fmt = pcm1681_set_dai_fmt,
>>> + .hw_params = pcm1681_hw_params,
>>> + .digital_mute = pcm1681_digital_mute,
>>> +};
>>> +
>>> +static const DECLARE_TLV_DB_SCALE(pcm1681_dac_tlv, -6350, 50, 1);
>>> +
>>> +static const struct snd_kcontrol_new pcm1681_controls[] = {
>>> + SOC_DOUBLE_R_TLV("PCM1681 Channel 1/2 Playback Volume",
>>> + PCM1681_ATT_CONTROL(1), PCM1681_ATT_CONTROL(2), 0,
>>> + 0x7f, 0, pcm1681_dac_tlv),
>>> + SOC_DOUBLE_R_TLV("PCM1681 Channel 3/4 Playback Volume",
>>> + PCM1681_ATT_CONTROL(3), PCM1681_ATT_CONTROL(4), 0,
>>> + 0x7f, 0, pcm1681_dac_tlv),
>>> + SOC_DOUBLE_R_TLV("PCM1681 Channel 5/6 Playback Volume",
>>> + PCM1681_ATT_CONTROL(5), PCM1681_ATT_CONTROL(6), 0,
>>> + 0x7f, 0, pcm1681_dac_tlv),
>>> + SOC_DOUBLE_R_TLV("PCM1681 Channel 7/8 Playback Volume",
>>> + PCM1681_ATT_CONTROL(7), PCM1681_ATT_CONTROL(8), 0,
>>> + 0x7f, 0, pcm1681_dac_tlv),
>>> + SOC_SINGLE_BOOL_EXT("PCM1681 De-emphasis Switch", 0,
>>> + pcm1681_get_deemph, pcm1681_put_deemph),
>>> +};
>>> +
>>> +struct snd_soc_dai_driver pcm1681_dai = {
>>> + .name = "pcm1681-hifi",
>>> + .playback = {
>>> + .stream_name = "Playback",
>>> + .channels_min = 2,
>>> + .channels_max = 8,
>>> + .rates = PCM1681_PCM_RATES,
>>> + .formats = PCM1681_PCM_FORMATS,
>>> + },
>>> + .ops = &pcm1681_dai_ops,
>>> +};
>>> +
>>> +#ifdef CONFIG_OF
>>> +static const struct of_device_id pcm1681_dt_ids[] = {
>>> + { .compatible = "ti,pcm1681", },
>>> + { }
>>> +};
>>> +MODULE_DEVICE_TABLE(of, pcm1681_dt_ids);
>>> +#endif
>>> +
>>> +static const struct regmap_config pcm1681_regmap = {
>>> + .reg_bits = 8,
>>> + .val_bits = 8,
>>> + .max_register = ARRAY_SIZE(pcm1681_reg_defaults),
>>> + .reg_defaults = pcm1681_reg_defaults,
>>> + .num_reg_defaults = ARRAY_SIZE(pcm1681_reg_defaults),
>>> + .writeable_reg = pcm1681_writeable_reg,
>>> + .readable_reg = pcm1681_accessible_reg,
>>> +};
>>> +
>>> +static int pcm1681_probe(struct snd_soc_codec *codec)
>>> +{
>>> + return 0;
>>
>> Is there really nothing the driver has to do in order to bring the codec
>> into full operation mode?
> This codec have only POWER-ON-RESET function. It means codec need system
> clock (normally MCLK) for some amount of time to get out of reset and
> then you can communicate with it.
>>
>>> +}
>>> +
>>> +static int pcm1681_remove(struct snd_soc_codec *codec)
>>> +{
>>> + return 0;
>>> +}
>>> +
>>> +static struct snd_soc_codec_driver soc_codec_dev_pcm1681 = {
>>> + .probe = pcm1681_probe,
>>> + .remove = pcm1681_remove,
>>> + .controls = pcm1681_controls,
>>> + .num_controls = ARRAY_SIZE(pcm1681_controls),
>>> +};
>>> +
>>> +#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
>>> +static const struct i2c_device_id pcm1681_i2c_id[] = {
>>> + {"pcm1681", 0},
>>> + {}
>>> +};
>>> +MODULE_DEVICE_TABLE(i2c, pcm1681_i2c_id);
>>> +
>>> +static int pcm1681_i2c_probe(struct i2c_client *client,
>>> + const struct i2c_device_id *id)
>>> +{
>>> + int ret;
>>> + struct pcm1681_private *priv;
>>> +
>>> + priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
>>> + if (!priv)
>>> + return -ENOMEM;
>>> +
>>> + priv->regmap = devm_regmap_init_i2c(client, &pcm1681_regmap);
>>> + if (IS_ERR(priv->regmap)) {
>>> + ret = PTR_ERR(priv->regmap);
>>> + dev_err(&client->dev, "Failed to create regmap: %d\n", ret);
>>> + return ret;
>>> + }
>>> +
>>> + i2c_set_clientdata(client, priv);
>>> +
>>
>> Is there any way to probe the device is there at all? I'd like to bail
>> early in case the bus or i2c address doesn't match for example.
> Probing is done here because we assume that codec is out of reset.

Yes, I know. I wondered whether there is any register that the driver
can read back in order to check the presence of the device. But I
quickly checked the datasheet, and there does in fact not seem to be
such a register.

>> Also, I wonder whether there are any reset lines that might be connected
>> to GPIOs of the MCU. If so, it would be good idea to add support for
>> that in this driver. But that can be done at some later point as well.
> No other pins which can be handled.

I see. Well ok then, I have no further remarks :)


Daniel

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