From: Shawn Guo shawn.guo@linaro.org
It's very common that audio card has a machine level amplifier which is controlled by GPIO. The patch adds DAPM widgets and routing support into audio-graph-card driver, and creates an output driver widget with event to control the amplifier via GPIO.
Signed-off-by: Shawn Guo shawn.guo@linaro.org --- sound/soc/generic/audio-graph-card.c | 48 +++++++++++++++++++++++++++++++++++- 1 file changed, 47 insertions(+), 1 deletion(-)
diff --git a/sound/soc/generic/audio-graph-card.c b/sound/soc/generic/audio-graph-card.c index 885b405d7844..a0bcebc77e2a 100644 --- a/sound/soc/generic/audio-graph-card.c +++ b/sound/soc/generic/audio-graph-card.c @@ -13,6 +13,7 @@ #include <linux/clk.h> #include <linux/device.h> #include <linux/gpio.h> +#include <linux/gpio/consumer.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_device.h> @@ -30,6 +31,34 @@ struct graph_card_data { struct asoc_simple_dai codec_dai; } *dai_props; struct snd_soc_dai_link *dai_link; + struct gpio_desc *pa_gpio; +}; + +static int asoc_graph_card_outdrv_event(struct snd_soc_dapm_widget *w, + struct snd_kcontrol *kcontrol, + int event) +{ + struct snd_soc_dapm_context *dapm = w->dapm; + struct graph_card_data *priv = snd_soc_card_get_drvdata(dapm->card); + + switch (event) { + case SND_SOC_DAPM_POST_PMU: + gpiod_set_value_cansleep(priv->pa_gpio, 1); + break; + case SND_SOC_DAPM_PRE_PMD: + gpiod_set_value_cansleep(priv->pa_gpio, 0); + break; + default: + return -EINVAL; + } + + return 0; +} + +static const struct snd_soc_dapm_widget asoc_graph_card_dapm_widgets[] = { + SND_SOC_DAPM_OUT_DRV_E("Amplifier", SND_SOC_NOPM, + 0, 0, NULL, 0, asoc_graph_card_outdrv_event, + SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_PMD), };
#define graph_priv_to_card(priv) (&(priv)->snd_card) @@ -181,8 +210,16 @@ static int asoc_graph_card_parse_of(struct graph_card_data *priv) int rc, idx = 0; int ret;
+ ret = asoc_simple_card_of_parse_widgets(card, NULL); + if (ret < 0) + return ret; + + ret = asoc_simple_card_of_parse_routing(card, NULL, 1); + if (ret < 0) + return ret; + /* - * we need to consider "widgets", "routing", "mclk-fs" around here + * we need to consider "mclk-fs" around here * see simple-card */
@@ -234,6 +271,13 @@ static int asoc_graph_card_probe(struct platform_device *pdev) if (!dai_props || !dai_link) return -ENOMEM;
+ priv->pa_gpio = devm_gpiod_get_optional(dev, "pa", GPIOD_OUT_LOW); + if (IS_ERR(priv->pa_gpio)) { + ret = PTR_ERR(priv->pa_gpio); + dev_err(dev, "failed to get amplifier gpio: %d\n", ret); + return ret; + } + priv->dai_props = dai_props; priv->dai_link = dai_link;
@@ -243,6 +287,8 @@ static int asoc_graph_card_probe(struct platform_device *pdev) card->dev = dev; card->dai_link = dai_link; card->num_links = num; + card->dapm_widgets = asoc_graph_card_dapm_widgets; + card->num_dapm_widgets = ARRAY_SIZE(asoc_graph_card_dapm_widgets);
ret = asoc_graph_card_parse_of(priv); if (ret < 0) {