fbdev: sh_mobile_meram: Backup/restore device registers on shutdown/resume

Save and reconfigure the MERAM registers when the MERAM is powered down
and restored

Signed-off-by: Damian Hobson-Garcia <dhobsong@igel.co.jp>

1 files changed, 71 insertions, 0 deletions

diff --git a/drivers/video/sh_mobile_meram.c b/drivers/video/sh_mobile_meram.c
index cfa1a78328aa..39f28a1aa074 100644
--- a/drivers/video/sh_mobile_meram.c
+++ b/drivers/video/sh_mobile_meram.c
@@ -37,12 +37,31 @@
 #define MEQSEL1 0x40
 #define MEQSEL2 0x44
 
+static unsigned long common_regs[] = {
+        MEVCR1,
+        MEQSEL1,
+        MEQSEL2,
+};
+#define CMN_REGS_SIZE ARRAY_SIZE(common_regs)
+
+static unsigned long icb_regs[] = {
+        MExxCTL,
+        MExxBSIZE,
+        MExxMNCF,
+        MExxSARA,
+        MExxSARB,
+        MExxSBSIZE,
+};
+#define ICB_REGS_SIZE ARRAY_SIZE(icb_regs)
+
 struct sh_mobile_meram_priv {
         void __iomem    *base;
         struct mutex    lock;
         unsigned long   used_icb;
         int             used_meram_cache_regions;
         unsigned long   used_meram_cache[SH_MOBILE_MERAM_ICB_NUM];
+        unsigned long   cmn_saved_regs[CMN_REGS_SIZE];
+        unsigned long   icb_saved_regs[ICB_REGS_SIZE * SH_MOBILE_MERAM_ICB_NUM];
 };
 
 /* settings */
@@ -469,6 +488,57 @@ static int sh_mobile_meram_update(struct sh_mobile_meram_info *pdata,
         return 0;
 }
 
+static int sh_mobile_meram_runtime_suspend(struct device *dev)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct sh_mobile_meram_priv *priv = platform_get_drvdata(pdev);
+        int k, j;
+
+        for (k = 0; k < CMN_REGS_SIZE; k++)
+                priv->cmn_saved_regs[k] = meram_read_reg(priv->base,
+                        common_regs[k]);
+
+        for (j = 0; j < 32; j++) {
+                if (!test_bit(j, &priv->used_icb))
+                        continue;
+                for (k = 0; k < ICB_REGS_SIZE; k++) {
+                        priv->icb_saved_regs[j * ICB_REGS_SIZE + k] =
+                                meram_read_icb(priv->base, j, icb_regs[k]);
+                        /* Reset ICB on resume */
+                        if (icb_regs[k] == MExxCTL)
+                                priv->icb_saved_regs[j * ICB_REGS_SIZE + k] =
+                                        0x70;
+                }
+        }
+        return 0;
+}
+
+static int sh_mobile_meram_runtime_resume(struct device *dev)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct sh_mobile_meram_priv *priv = platform_get_drvdata(pdev);
+        int k, j;
+
+        for (j = 0; j < 32; j++) {
+                if (!test_bit(j, &priv->used_icb))
+                        continue;
+                for (k = 0; k < ICB_REGS_SIZE; k++) {
+                        meram_write_icb(priv->base, j, icb_regs[k],
+                        priv->icb_saved_regs[j * ICB_REGS_SIZE + k]);
+                }
+        }
+
+        for (k = 0; k < CMN_REGS_SIZE; k++)
+                meram_write_reg(priv->base, common_regs[k],
+                        priv->cmn_saved_regs[k]);
+        return 0;
+}
+
+static const struct dev_pm_ops sh_mobile_meram_dev_pm_ops = {
+        .runtime_suspend = sh_mobile_meram_runtime_suspend,
+        .runtime_resume = sh_mobile_meram_runtime_resume,
+};
+
 static struct sh_mobile_meram_ops sh_mobile_meram_ops = {
         .module                 = THIS_MODULE,
         .meram_register         = sh_mobile_meram_register,
@@ -557,6 +627,7 @@ static struct platform_driver sh_mobile_meram_driver = {
         .driver = {
                 .name           = "sh_mobile_meram",
                 .owner          = THIS_MODULE,
+                .pm             = &sh_mobile_meram_dev_pm_ops,
         },
         .probe          = sh_mobile_meram_probe,
         .remove         = sh_mobile_meram_remove,