[alsa-devel] [PATCH 2/3] ASoC: Intel: detect audio routing with CHAN package

[Pierre-Louis Bossart]

Baytrail-CR devices usually expose information in the DSDT
which can be used to auto-detect AIF1/AIF2 connections.
The CHAN package contains two integers, the first one describes
the AIF number (1: AIF1, 2: AIF2) and the second the MCLK
value (ignored in this patch)

For example the following information is found in Lenovo 100s:

Device (RTEK) {
[...]
    Name (CHAN, Package (0x02)
    {
        One,
        0x017D7840
    })

While on Asus T100TAF the package values are:

    Name (CHAN, Package (0x02)
    {
        0x02,
        0x017D7840
    })

This patch relies on the new common routine to extract
a package exposed by a device indexed with the HID value.
The CHAN package contents are queried from the machine driver
and stored in a structure.

If this auto-detection fails (missing or bad package in the
BIOS), the routing falls back to SSP0-AIF2.

Note that quirks may still be needed to support mono speakers
or microphone, but this should reduce the number of issues with
Baytrail significantly.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
---
 sound/soc/intel/boards/bytcr_rt5640.c | 53 +++++++++++++++++++++++++++++++++--
 1 file changed, 51 insertions(+), 2 deletions(-)

diff --git a/sound/soc/intel/boards/bytcr_rt5640.c b/sound/soc/intel/boards/bytcr_rt5640.c
index 751e009..63a7993 100644
--- a/sound/soc/intel/boards/bytcr_rt5640.c
+++ b/sound/soc/intel/boards/bytcr_rt5640.c
@@ -689,6 +689,10 @@ static bool is_valleyview(void)
 	return true;
 }
 
+struct acpi_chan_package {   /* ACPICA seems to require 64 bit integers */
+	u64 aif_value;       /* 1: AIF1, 2: AIF2 */
+	u64 mclock_value;    /* usually 25MHz (0x17d7940), ignored */
+};
 
 static int snd_byt_rt5640_mc_probe(struct platform_device *pdev)
 {
@@ -698,6 +702,7 @@ static int snd_byt_rt5640_mc_probe(struct platform_device *pdev)
 	int i;
 	int dai_index;
 	struct byt_rt5640_private *priv;
+	bool is_bytcr = false;
 
 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_ATOMIC);
 	if (!priv)
@@ -734,8 +739,52 @@ static int snd_byt_rt5640_mc_probe(struct platform_device *pdev)
 		struct sst_platform_info *p_info = mach->pdata;
 		const struct sst_res_info *res_info = p_info->res_info;
 
-		/* TODO: use CHAN package info from BIOS to detect AIF1/AIF2 */
-		if (res_info->acpi_ipc_irq_index == 0) {
+		if (res_info->acpi_ipc_irq_index == 0)
+			is_bytcr = true;
+	}
+
+	if (is_bytcr) {
+		/*
+		 * Baytrail CR platforms may have CHAN package in BIOS, try
+		 * to find relevant routing quirk based as done on Windows
+		 * platforms. We have to read the information directly from the
+		 * BIOS, at this stage the card is not created and the links
+		 * with the codec driver/pdata are non-existent
+		 */
+
+		struct acpi_chan_package chan_package;
+
+		/* format specified: 2 64-bit integers */
+		struct acpi_buffer format = {sizeof("NN"), "NN"};
+		struct acpi_buffer state = {0, NULL};
+		struct sst_acpi_package_context pkg_ctx;
+		bool pkg_found = false;
+
+		state.length = sizeof(chan_package);
+		state.pointer = &chan_package;
+
+		pkg_ctx.name = "CHAN";
+		pkg_ctx.length = 2;
+		pkg_ctx.format = &format;
+		pkg_ctx.state = &state;
+		pkg_ctx.data_valid = false;
+
+		pkg_found = sst_acpi_find_package_from_hid(mach->id, &pkg_ctx);
+		if (pkg_found) {
+			if (chan_package.aif_value == 1) {
+				dev_info(&pdev->dev, "BIOS Routing: AIF1 connected\n");
+				byt_rt5640_quirk |= BYT_RT5640_SSP0_AIF1;
+			} else  if (chan_package.aif_value == 2) {
+				dev_info(&pdev->dev, "BIOS Routing: AIF2 connected\n");
+				byt_rt5640_quirk |= BYT_RT5640_SSP0_AIF2;
+			} else {
+				dev_info(&pdev->dev, "BIOS Routing isn't valid, ignored\n");
+				pkg_found = false;
+			}
+		}
+
+		if (!pkg_found) {
+			/* no BIOS indications, assume SSP0-AIF2 connection */
 			byt_rt5640_quirk |= BYT_RT5640_SSP0_AIF2;
 		}
 	}
-- 
2.7.4