[PATCH v2 0/3] ASoC: wm8782: Allow higher audio rates
The wm8782 supports higher audio rates than just 48kHz. This is configured by setting the FSAMPEN pin on the codec chip.
This patch series introduces the 'wlf,fsampen' device tree property to indicate the pin status and control the maximum rate available when using the codec.
v1 -> v2: - Switched from max-rate property to wlf,fsampen property - Clarified property is optional, not required
John Watts (3): ASoC: wm8782: Handle maximum audio rate at runtime ASoC: wm8782: Use wlf,fsampen device tree property ASoC: dt-bindings: wlf,wm8782: Add wlf,fsampen property
.../devicetree/bindings/sound/wm8782.txt | 5 ++ sound/soc/codecs/wm8782.c | 66 +++++++++++++++---- 2 files changed, 58 insertions(+), 13 deletions(-)
The wm8782 supports up to 192kHz audio when pins are set correctly. Instead of hardcoding which rates are supported enable them all then refer to a max_rate variable at runtime.
Signed-off-by: John Watts contact@jookia.org --- sound/soc/codecs/wm8782.c | 45 ++++++++++++++++++++++++++++----------- 1 file changed, 33 insertions(+), 12 deletions(-)
diff --git a/sound/soc/codecs/wm8782.c b/sound/soc/codecs/wm8782.c index 95ff4339d103..63ab63f3189a 100644 --- a/sound/soc/codecs/wm8782.c +++ b/sound/soc/codecs/wm8782.c @@ -23,6 +23,30 @@ #include <sound/initval.h> #include <sound/soc.h>
+/* regulator power supply names */ +static const char *supply_names[] = { + "Vdda", /* analog supply, 2.7V - 3.6V */ + "Vdd", /* digital supply, 2.7V - 5.5V */ +}; + +struct wm8782_priv { + struct regulator_bulk_data supplies[ARRAY_SIZE(supply_names)]; + int max_rate; +}; + +static int wm8782_dai_hw_params(struct snd_pcm_substream *component, + struct snd_pcm_hw_params *params, + struct snd_soc_dai *dai) +{ + struct wm8782_priv *priv = + snd_soc_component_get_drvdata(dai->component); + + if (params_rate(params) > priv->max_rate) + return -EINVAL; + + return 0; +} + static const struct snd_soc_dapm_widget wm8782_dapm_widgets[] = { SND_SOC_DAPM_INPUT("AINL"), SND_SOC_DAPM_INPUT("AINR"), @@ -33,28 +57,22 @@ static const struct snd_soc_dapm_route wm8782_dapm_routes[] = { { "Capture", NULL, "AINR" }, };
+static const struct snd_soc_dai_ops wm8782_dai_ops = { + .hw_params = &wm8782_dai_hw_params, +}; + static struct snd_soc_dai_driver wm8782_dai = { .name = "wm8782", .capture = { .stream_name = "Capture", .channels_min = 2, .channels_max = 2, - /* For configurations with FSAMPEN=0 */ - .rates = SNDRV_PCM_RATE_8000_48000, + .rates = SNDRV_PCM_RATE_8000_192000, .formats = SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S24_LE, }, -}; - -/* regulator power supply names */ -static const char *supply_names[] = { - "Vdda", /* analog supply, 2.7V - 3.6V */ - "Vdd", /* digital supply, 2.7V - 5.5V */ -}; - -struct wm8782_priv { - struct regulator_bulk_data supplies[ARRAY_SIZE(supply_names)]; + .ops = &wm8782_dai_ops, };
static int wm8782_soc_probe(struct snd_soc_component *component) @@ -121,6 +139,9 @@ static int wm8782_probe(struct platform_device *pdev) if (ret < 0) return ret;
+ /* For configurations with FSAMPEN=0 */ + priv->max_rate = 48000; + return devm_snd_soc_register_component(&pdev->dev, &soc_component_dev_wm8782, &wm8782_dai, 1); }
On Thu, Sep 14, 2023 at 03:15:50AM +1000, John Watts wrote:
The wm8782 supports up to 192kHz audio when pins are set correctly. Instead of hardcoding which rates are supported enable them all then refer to a max_rate variable at runtime.
Signed-off-by: John Watts contact@jookia.org
+static int wm8782_dai_hw_params(struct snd_pcm_substream *component,
struct snd_pcm_hw_params *params,struct snd_soc_dai *dai)+{
- struct wm8782_priv *priv =
snd_soc_component_get_drvdata(dai->component);- if (params_rate(params) > priv->max_rate)
return -EINVAL;- return 0;
+}
We should be setting this as a constraint in startup, rather than returning an error in hw_params. That will let user-space know the supported rates and allow it to resample if necessary.
Thanks, Charles
On Thu, Sep 14, 2023 at 09:21:07AM +0000, Charles Keepax wrote:
On Thu, Sep 14, 2023 at 03:15:50AM +1000, John Watts wrote:
The wm8782 supports up to 192kHz audio when pins are set correctly. Instead of hardcoding which rates are supported enable them all then refer to a max_rate variable at runtime.
Signed-off-by: John Watts contact@jookia.org
+static int wm8782_dai_hw_params(struct snd_pcm_substream *component,
struct snd_pcm_hw_params *params,struct snd_soc_dai *dai)+{
- struct wm8782_priv *priv =
snd_soc_component_get_drvdata(dai->component);- if (params_rate(params) > priv->max_rate)
return -EINVAL;- return 0;
+}
We should be setting this as a constraint in startup, rather than returning an error in hw_params. That will let user-space know the supported rates and allow it to resample if necessary.
How do you do this? The struct with the rate is statically defined.
Thanks, Charles
John.
On Thu, Sep 14, 2023 at 07:27:03PM +1000, John Watts wrote:
On Thu, Sep 14, 2023 at 09:21:07AM +0000, Charles Keepax wrote:
On Thu, Sep 14, 2023 at 03:15:50AM +1000, John Watts wrote:
The wm8782 supports up to 192kHz audio when pins are set correctly. Instead of hardcoding which rates are supported enable them all then refer to a max_rate variable at runtime.
Signed-off-by: John Watts contact@jookia.org
+static int wm8782_dai_hw_params(struct snd_pcm_substream *component,
struct snd_pcm_hw_params *params,struct snd_soc_dai *dai)+{
- struct wm8782_priv *priv =
snd_soc_component_get_drvdata(dai->component);- if (params_rate(params) > priv->max_rate)
return -EINVAL;- return 0;
+}
We should be setting this as a constraint in startup, rather than returning an error in hw_params. That will let user-space know the supported rates and allow it to resample if necessary.
How do you do this? The struct with the rate is statically defined.
You can programmatically add additional constraints, commonly this will be done from the startup callback on the DAI. See something like arizona_startup in sound/soc/codecs/arizona.c for an example, that enables 44.1/48k rates based on clocks but the principle should be similar.
Thanks, Charles
On Thu, Sep 14, 2023 at 09:37:31AM +0000, Charles Keepax wrote:
On Thu, Sep 14, 2023 at 07:27:03PM +1000, John Watts wrote:
On Thu, Sep 14, 2023 at 09:21:07AM +0000, Charles Keepax wrote:
On Thu, Sep 14, 2023 at 03:15:50AM +1000, John Watts wrote:
The wm8782 supports up to 192kHz audio when pins are set correctly. Instead of hardcoding which rates are supported enable them all then refer to a max_rate variable at runtime.
Signed-off-by: John Watts contact@jookia.org
+static int wm8782_dai_hw_params(struct snd_pcm_substream *component,
struct snd_pcm_hw_params *params,struct snd_soc_dai *dai)+{
- struct wm8782_priv *priv =
snd_soc_component_get_drvdata(dai->component);- if (params_rate(params) > priv->max_rate)
return -EINVAL;- return 0;
+}
We should be setting this as a constraint in startup, rather than returning an error in hw_params. That will let user-space know the supported rates and allow it to resample if necessary.
How do you do this? The struct with the rate is statically defined.
You can programmatically add additional constraints, commonly this will be done from the startup callback on the DAI. See something like arizona_startup in sound/soc/codecs/arizona.c for an example, that enables 44.1/48k rates based on clocks but the principle should be similar.
Although I would also imagine snd_pcm_hw_constraint_minmax is going to be more appropriate in your case.
Thanks, Charles
The wm8782 supports rates 96kHz and 192kHz as long as the hardware is configured properly. Allow this to be specified in the device tree.
Signed-off-by: John Watts contact@jookia.org --- sound/soc/codecs/wm8782.c | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-)
diff --git a/sound/soc/codecs/wm8782.c b/sound/soc/codecs/wm8782.c index 63ab63f3189a..249b58b093d6 100644 --- a/sound/soc/codecs/wm8782.c +++ b/sound/soc/codecs/wm8782.c @@ -122,8 +122,9 @@ static const struct snd_soc_component_driver soc_component_dev_wm8782 = { static int wm8782_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; struct wm8782_priv *priv; - int ret, i; + int ret, i, fsampen;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); if (!priv) @@ -139,8 +140,26 @@ static int wm8782_probe(struct platform_device *pdev) if (ret < 0) return ret;
- /* For configurations with FSAMPEN=0 */ - priv->max_rate = 48000; + // Assume lowest value by default to avoid inadvertent overclocking + fsampen = 0; + + if (np) + of_property_read_u32(np, "wlf,fsampen", &fsampen); + + switch (fsampen) { + case 0: + priv->max_rate = 48000; + break; + case 1: + priv->max_rate = 96000; + break; + case 2: + priv->max_rate = 192000; + break; + default: + dev_err(dev, "Invalid wlf,fsampen value"); + return -EINVAL; + }
return devm_snd_soc_register_component(&pdev->dev, &soc_component_dev_wm8782, &wm8782_dai, 1);
The WM8782 can safely support rates higher than 48kHz by changing the value of the FSAMPEN pin.
Allow specifying the FSAMPEN pin value in the device tree.
Signed-off-by: John Watts contact@jookia.org --- Documentation/devicetree/bindings/sound/wm8782.txt | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/Documentation/devicetree/bindings/sound/wm8782.txt b/Documentation/devicetree/bindings/sound/wm8782.txt index 256cdec6ec4d..d217a616e103 100644 --- a/Documentation/devicetree/bindings/sound/wm8782.txt +++ b/Documentation/devicetree/bindings/sound/wm8782.txt @@ -8,10 +8,15 @@ Required properties: - Vdda-supply : phandle to a regulator for the analog power supply (2.7V - 5.5V) - Vdd-supply : phandle to a regulator for the digital power supply (2.7V - 3.6V)
+Optional properties: + + - wlf,fsampen : FSAMPEN pin value, 0 for low, 1 for high, 2 for disconnected + Example:
wm8782: stereo-adc { compatible = "wlf,wm8782"; Vdda-supply = <&vdda_supply>; Vdd-supply = <&vdd_supply>; + wlf,fsampen = <2>; /* 192KHz */ };
On Thu, Sep 14, 2023 at 03:15:52AM +1000, John Watts wrote:
The WM8782 can safely support rates higher than 48kHz by changing the value of the FSAMPEN pin.
Allow specifying the FSAMPEN pin value in the device tree.
Signed-off-by: John Watts contact@jookia.org
Documentation/devicetree/bindings/sound/wm8782.txt | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/Documentation/devicetree/bindings/sound/wm8782.txt b/Documentation/devicetree/bindings/sound/wm8782.txt index 256cdec6ec4d..d217a616e103 100644 --- a/Documentation/devicetree/bindings/sound/wm8782.txt +++ b/Documentation/devicetree/bindings/sound/wm8782.txt @@ -8,10 +8,15 @@ Required properties:
- Vdda-supply : phandle to a regulator for the analog power supply (2.7V - 5.5V)
- Vdd-supply : phandle to a regulator for the digital power supply (2.7V - 3.6V)
+Optional properties:
- wlf,fsampen : FSAMPEN pin value, 0 for low, 1 for high, 2 for disconnected
What's the default if the property is not present?
Example:
wm8782: stereo-adc { compatible = "wlf,wm8782"; Vdda-supply = <&vdda_supply>; Vdd-supply = <&vdd_supply>;
- wlf,fsampen = <2>; /* 192KHz */
};
2.42.0
On Fri, Sep 15, 2023 at 03:39:49PM +1000, John Watts wrote:
On Thu, Sep 14, 2023 at 09:52:34AM -0500, Rob Herring wrote:
What's the default if the property is not present?
- Should I specify it here?
Yes.
participants (4)
-
Charles Keepax -
John Watts -
Mark Brown -
Rob Herring