Applied "ASoC: imx-audmux: Add driver suspend and resume to support MEGA Fast" to the asoc tree

[Mark Brown]

The patch

   ASoC: imx-audmux: Add driver suspend and resume to support MEGA Fast

has been applied to the asoc tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-5.3

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 8661ab5b23d6d30d8687fc05bc1dba8f9a64b444 Mon Sep 17 00:00:00 2001
From: Shengjiu Wang <shengjiu.wang at nxp.com>
Date: Fri, 16 Aug 2019 01:03:14 -0400
Subject: [PATCH] ASoC: imx-audmux: Add driver suspend and resume to support
 MEGA Fast

For i.MX6 SoloX, there is a mode of the SoC to shutdown all power
source of modules during system suspend and resume procedure.
Thus, AUDMUX needs to save all the values of registers before the
system suspend and restore them after the system resume.

Signed-off-by: Shengjiu Wang <shengjiu.wang at nxp.com>
Link: https://lore.kernel.org/r/1565931794-7218-1-git-send-email-shengjiu.wang@nxp.com
Signed-off-by: Mark Brown <broonie at kernel.org>
---
 sound/soc/fsl/imx-audmux.c | 54 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 53 insertions(+), 1 deletion(-)

diff --git a/sound/soc/fsl/imx-audmux.c b/sound/soc/fsl/imx-audmux.c
index b2351cd33b0f..16ede3b5cb32 100644
--- a/sound/soc/fsl/imx-audmux.c
+++ b/sound/soc/fsl/imx-audmux.c
@@ -23,6 +23,8 @@
 
 static struct clk *audmux_clk;
 static void __iomem *audmux_base;
+static u32 *regcache;
+static u32 reg_max;
 
 #define IMX_AUDMUX_V2_PTCR(x)		((x) * 8)
 #define IMX_AUDMUX_V2_PDCR(x)		((x) * 8 + 4)
@@ -317,8 +319,23 @@ static int imx_audmux_probe(struct platform_device *pdev)
 	if (of_id)
 		pdev->id_entry = of_id->data;
 	audmux_type = pdev->id_entry->driver_data;
-	if (audmux_type == IMX31_AUDMUX)
+
+	switch (audmux_type) {
+	case IMX31_AUDMUX:
 		audmux_debugfs_init();
+		reg_max = 14;
+		break;
+	case IMX21_AUDMUX:
+		reg_max = 6;
+		break;
+	default:
+		dev_err(&pdev->dev, "unsupported version!\n");
+		return -EINVAL;
+	}
+
+	regcache = devm_kzalloc(&pdev->dev, sizeof(u32) * reg_max, GFP_KERNEL);
+	if (!regcache)
+		return -ENOMEM;
 
 	if (of_id)
 		imx_audmux_parse_dt_defaults(pdev, pdev->dev.of_node);
@@ -334,12 +351,47 @@ static int imx_audmux_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int imx_audmux_suspend(struct device *dev)
+{
+	int i;
+
+	clk_prepare_enable(audmux_clk);
+
+	for (i = 0; i < reg_max; i++)
+		regcache[i] = readl(audmux_base + i * 4);
+
+	clk_disable_unprepare(audmux_clk);
+
+	return 0;
+}
+
+static int imx_audmux_resume(struct device *dev)
+{
+	int i;
+
+	clk_prepare_enable(audmux_clk);
+
+	for (i = 0; i < reg_max; i++)
+		writel(regcache[i], audmux_base + i * 4);
+
+	clk_disable_unprepare(audmux_clk);
+
+	return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops imx_audmux_pm = {
+	SET_SYSTEM_SLEEP_PM_OPS(imx_audmux_suspend, imx_audmux_resume)
+};
+
 static struct platform_driver imx_audmux_driver = {
 	.probe		= imx_audmux_probe,
 	.remove		= imx_audmux_remove,
 	.id_table	= imx_audmux_ids,
 	.driver	= {
 		.name	= DRIVER_NAME,
+		.pm = &imx_audmux_pm,
 		.of_match_table = imx_audmux_dt_ids,
 	}
 };
-- 
2.20.1