Applied "ASoC: Intel: cht_bsw_max98090: add support for Baytrail" to the asoc tree

[Mark Brown <broonie@kernel.org>]

The patch

   ASoC: Intel: cht_bsw_max98090: add support for Baytrail

has been applied to the asoc tree at

   git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

>From 299bad365b900223cded22a6f66dbb3763da4235 Mon Sep 17 00:00:00 2001
From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Date: Fri, 8 Sep 2017 00:13:05 -0500
Subject: [PATCH] ASoC: Intel: cht_bsw_max98090: add support for Baytrail

Distributions such as Fedora, Ubuntu and Gallium don't currently
have a means to support Baytrail Chromebooks and other platforms
with the same build [1][2] due to incompatible platform drivers.

Add MCLK management to reuse this machine driver for Baytrail
platforms and solve this coexistence problem at last. UCM files are
provided at [3] and will eventually be submitted to the new repo.

The legacy byt-max98090 machine driver is still maintained but can
only be used when the other Atom/DPCM driver is not compiled in, or
when users don't want to configure extra mixers required by the
Atom/sst driver.

Tested on Lenovo 100s Baytrail Chromebook w/ Mr. Chromebox BOOT_STUB
firmware and Acer R11 Cherrytrail Chromebook

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1335196
[2] http://mailman.alsa-project.org/pipermail/alsa-devel/2016-August/
111641.html
[3] https://github.com/plbossart/UCM/tree/master/byt-max98090

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Acked-By: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 sound/soc/intel/boards/cht_bsw_max98090_ti.c | 78 ++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/sound/soc/intel/boards/cht_bsw_max98090_ti.c b/sound/soc/intel/boards/cht_bsw_max98090_ti.c
index 20755ecc7f9e..442a81bf17b4 100644
--- a/sound/soc/intel/boards/cht_bsw_max98090_ti.c
+++ b/sound/soc/intel/boards/cht_bsw_max98090_ti.c
@@ -23,6 +23,7 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/acpi.h>
+#include <linux/clk.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/soc.h>
@@ -35,15 +36,60 @@
 #define CHT_CODEC_DAI	"HiFi"
 
 struct cht_mc_private {
+	struct clk *mclk;
 	struct snd_soc_jack jack;
 	bool ts3a227e_present;
 };
 
+static inline struct snd_soc_dai *cht_get_codec_dai(struct snd_soc_card *card)
+{
+	struct snd_soc_pcm_runtime *rtd;
+
+	list_for_each_entry(rtd, &card->rtd_list, list) {
+		if (!strncmp(rtd->codec_dai->name, CHT_CODEC_DAI,
+			     strlen(CHT_CODEC_DAI)))
+			return rtd->codec_dai;
+	}
+	return NULL;
+}
+
+static int platform_clock_control(struct snd_soc_dapm_widget *w,
+					  struct snd_kcontrol *k, int  event)
+{
+	struct snd_soc_dapm_context *dapm = w->dapm;
+	struct snd_soc_card *card = dapm->card;
+	struct snd_soc_dai *codec_dai;
+	struct cht_mc_private *ctx = snd_soc_card_get_drvdata(card);
+	int ret;
+
+	codec_dai = cht_get_codec_dai(card);
+	if (!codec_dai) {
+		dev_err(card->dev, "Codec dai not found; Unable to set platform clock\n");
+		return -EIO;
+	}
+
+	if (SND_SOC_DAPM_EVENT_ON(event)) {
+		ret = clk_prepare_enable(ctx->mclk);
+		if (ret < 0) {
+			dev_err(card->dev,
+				"could not configure MCLK state");
+			return ret;
+		}
+	} else {
+		clk_disable_unprepare(ctx->mclk);
+	}
+
+	return 0;
+}
+
 static const struct snd_soc_dapm_widget cht_dapm_widgets[] = {
 	SND_SOC_DAPM_HP("Headphone", NULL),
 	SND_SOC_DAPM_MIC("Headset Mic", NULL),
 	SND_SOC_DAPM_MIC("Int Mic", NULL),
 	SND_SOC_DAPM_SPK("Ext Spk", NULL),
+	SND_SOC_DAPM_SUPPLY("Platform Clock", SND_SOC_NOPM, 0, 0,
+			    platform_clock_control, SND_SOC_DAPM_PRE_PMU |
+			    SND_SOC_DAPM_POST_PMD),
 };
 
 static const struct snd_soc_dapm_route cht_audio_map[] = {
@@ -60,6 +106,10 @@ static const struct snd_soc_dapm_route cht_audio_map[] = {
 	{"codec_in0", NULL, "ssp2 Rx" },
 	{"codec_in1", NULL, "ssp2 Rx" },
 	{"ssp2 Rx", NULL, "HiFi Capture"},
+	{"Headphone", NULL, "Platform Clock"},
+	{"Headset Mic", NULL, "Platform Clock"},
+	{"Int Mic", NULL, "Platform Clock"},
+	{"Ext Spk", NULL, "Platform Clock"},
 };
 
 static const struct snd_kcontrol_new cht_mc_controls[] = {
@@ -141,6 +191,25 @@ static int cht_codec_init(struct snd_soc_pcm_runtime *runtime)
 	if (ctx->ts3a227e_present)
 		snd_soc_jack_notifier_register(jack, &cht_jack_nb);
 
+	/*
+	 * The firmware might enable the clock at
+	 * boot (this information may or may not
+	 * be reflected in the enable clock register).
+	 * To change the rate we must disable the clock
+	 * first to cover these cases. Due to common
+	 * clock framework restrictions that do not allow
+	 * to disable a clock that has not been enabled,
+	 * we need to enable the clock first.
+	 */
+	ret = clk_prepare_enable(ctx->mclk);
+	if (!ret)
+		clk_disable_unprepare(ctx->mclk);
+
+	ret = clk_set_rate(ctx->mclk, CHT_PLAT_CLK_3_HZ);
+
+	if (ret)
+		dev_err(runtime->dev, "unable to set MCLK rate\n");
+
 	return ret;
 }
 
@@ -294,6 +363,15 @@ static int snd_cht_mc_probe(struct platform_device *pdev)
 	/* register the soc card */
 	snd_soc_card_cht.dev = &pdev->dev;
 	snd_soc_card_set_drvdata(&snd_soc_card_cht, drv);
+
+	drv->mclk = devm_clk_get(&pdev->dev, "pmc_plt_clk_3");
+	if (IS_ERR(drv->mclk)) {
+		dev_err(&pdev->dev,
+			"Failed to get MCLK from pmc_plt_clk_3: %ld\n",
+			PTR_ERR(drv->mclk));
+		return PTR_ERR(drv->mclk);
+	}
+
 	ret_val = devm_snd_soc_register_card(&pdev->dev, &snd_soc_card_cht);
 	if (ret_val) {
 		dev_err(&pdev->dev,
-- 
2.14.1