linux-kernel - [PATCH 2/2] ASoC: imx-rpmsg: Force codec power on in low power audio mode

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20230925024847.2971421-2-chancel.liu@nxp.com>
Date:   Mon, 25 Sep 2023 10:48:47 +0800
From:   Chancel Liu <chancel.liu@....com>
To:     lgirdwood@...il.com, broonie@...nel.org, robh+dt@...nel.org,
        krzysztof.kozlowski+dt@...aro.org, conor+dt@...nel.org,
        shengjiu.wang@...il.com, Xiubo.Lee@...il.com, festevam@...il.com,
        nicoleotsuka@...il.com, perex@...ex.cz, tiwai@...e.com,
        shawnguo@...nel.org, s.hauer@...gutronix.de, kernel@...gutronix.de,
        alsa-devel@...a-project.org, linux-kernel@...r.kernel.org,
        linuxppc-dev@...ts.ozlabs.org, devicetree@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org
Cc:     Chancel Liu <chancel.liu@....com>
Subject: [PATCH 2/2] ASoC: imx-rpmsg: Force codec power on in low power audio mode

Low power audio mode requires binding codec still power on while Acore
enters into suspend so Mcore can continue playback music.

ASoC machine driver acquires DAPM endpoints through reading
"fsl,lpa-widgets" property from DT and then forces the path between
these endpoints ignoring suspend.

If the rpmsg sound card is in low power audio mode, the suspend/resume
callback of binding codec is overridden to disable the suspend/resume.

Signed-off-by: Chancel Liu <chancel.liu@....com>
---
 sound/soc/fsl/imx-rpmsg.c | 58 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)

diff --git a/sound/soc/fsl/imx-rpmsg.c b/sound/soc/fsl/imx-rpmsg.c
index b578f9a32d7f..0568a3420aae 100644
--- a/sound/soc/fsl/imx-rpmsg.c
+++ b/sound/soc/fsl/imx-rpmsg.c
@@ -20,8 +20,11 @@ struct imx_rpmsg {
 	struct snd_soc_dai_link dai;
 	struct snd_soc_card card;
 	unsigned long sysclk;
+	bool lpa;
 };
 
+static struct dev_pm_ops lpa_pm;
+
 static const struct snd_soc_dapm_widget imx_rpmsg_dapm_widgets[] = {
 	SND_SOC_DAPM_HP("Headphone Jack", NULL),
 	SND_SOC_DAPM_SPK("Ext Spk", NULL),
@@ -38,6 +41,58 @@ static int imx_rpmsg_late_probe(struct snd_soc_card *card)
 	struct device *dev = card->dev;
 	int ret;
 
+	if (data->lpa) {
+		struct snd_soc_component *codec_comp;
+		struct device_node *codec_np;
+		struct device_driver *codec_drv;
+		struct device *codec_dev = NULL;
+
+		codec_np = data->dai.codecs->of_node;
+		if (codec_np) {
+			struct platform_device *codec_pdev;
+			struct i2c_client *codec_i2c;
+
+			codec_i2c = of_find_i2c_device_by_node(codec_np);
+			if (codec_i2c)
+				codec_dev = &codec_i2c->dev;
+			if (!codec_dev) {
+				codec_pdev = of_find_device_by_node(codec_np);
+				if (codec_pdev)
+					codec_dev = &codec_pdev->dev;
+			}
+		}
+		if (codec_dev) {
+			codec_comp = snd_soc_lookup_component_nolocked(codec_dev, NULL);
+			if (codec_comp) {
+				int i, num_widgets;
+				const char *widgets;
+				struct snd_soc_dapm_context *dapm;
+
+				num_widgets = of_property_count_strings(data->card.dev->of_node,
+									"fsl,lpa-widgets");
+				for (i = 0; i < num_widgets; i++) {
+					of_property_read_string_index(data->card.dev->of_node,
+								      "fsl,lpa-widgets",
+								      i, &widgets);
+					dapm = snd_soc_component_get_dapm(codec_comp);
+					snd_soc_dapm_ignore_suspend(dapm, widgets);
+				}
+			}
+			codec_drv = codec_dev->driver;
+			if (codec_drv->pm) {
+				memcpy(&lpa_pm, codec_drv->pm, sizeof(lpa_pm));
+				lpa_pm.suspend = NULL;
+				lpa_pm.resume = NULL;
+				lpa_pm.freeze = NULL;
+				lpa_pm.thaw = NULL;
+				lpa_pm.poweroff = NULL;
+				lpa_pm.restore = NULL;
+				codec_drv->pm = &lpa_pm;
+			}
+			put_device(codec_dev);
+		}
+	}
+
 	if (!data->sysclk)
 		return 0;
 
@@ -137,6 +192,9 @@ static int imx_rpmsg_probe(struct platform_device *pdev)
 		goto fail;
 	}
 
+	if (of_property_read_bool(np, "fsl,enable-lpa"))
+		data->lpa = true;
+
 	data->card.dev = &pdev->dev;
 	data->card.owner = THIS_MODULE;
 	data->card.dapm_widgets = imx_rpmsg_dapm_widgets;
-- 
2.25.1