ENGR00318773-10 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.

Acked-by: Wang Shengjiu <b02247@freescale.com>
Signed-off-by: Nicolin Chen <Guangyu.Chen@freescale.com>

1 files changed, 53 insertions, 2 deletions

diff --git a/sound/soc/fsl/imx-audmux.c b/sound/soc/fsl/imx-audmux.c
index 47f046a8fdab..3439232315df 100644
--- a/sound/soc/fsl/imx-audmux.c
+++ b/sound/soc/fsl/imx-audmux.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012 Freescale Semiconductor, Inc.
+ * Copyright 2012-2014 Freescale Semiconductor, Inc.
  * Copyright 2012 Linaro Ltd.
  * Copyright 2009 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de>
  *
@@ -34,6 +34,8 @@
 
 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)
@@ -272,8 +274,22 @@ 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;
+        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;
 
         return 0;
 }
@@ -286,6 +302,40 @@ 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,
@@ -293,6 +343,7 @@ static struct platform_driver imx_audmux_driver = {
         .driver = {
                 .name   = DRIVER_NAME,
                 .owner  = THIS_MODULE,
+                .pm = &imx_audmux_pm,
                 .of_match_table = imx_audmux_dt_ids,
         }
 };