[PATCH 1/2] iommu: Add M2 support to Apple DART driver

[Janne Grunau]

"apple,t8112-dart" uses an incompatible register interface but still
offers the same functionality. This DART is found on the M2 and M1
Pro/Max/Ultra SoCs.

Signed-off-by: Janne Grunau <j...@jannau.net>
---
 drivers/iommu/apple_dart.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/apple_dart.c b/drivers/iommu/apple_dart.c
index f2e170096072..2faacb8f3b6f 100644
--- a/drivers/iommu/apple_dart.c
+++ b/drivers/iommu/apple_dart.c
@@ -24,6 +24,12 @@
 #define  DART_TTBR_VALID       BIT(31)
 #define  DART_TTBR_SHIFT       12
 
+#define DART_T8110_TCR(sid)    (0x1000 + 4 * (sid))
+#define  DART_T8110_TCR_BYPASS_DAPF            BIT(2)
+#define  DART_T8110_TCR_BYPASS_DART            BIT(1)
+#define  DART_T8110_TCR_TRANSLATE_ENABLE       BIT(0)
+#define DART_T8110_TTBR(sid)   (0x1400 + 4 * (sid))
+
 static int apple_dart_probe(struct udevice *dev)
 {
        void *base;
@@ -34,7 +40,16 @@ static int apple_dart_probe(struct udevice *dev)
                return -EINVAL;
 
        u32 params2 = readl(base + DART_PARAMS2);
-       if (params2 & DART_PARAMS2_BYPASS_SUPPORT) {
+       if (!(params2 & DART_PARAMS2_BYPASS_SUPPORT))
+               return 0;
+
+       if (device_is_compatible(dev, "apple,t8112-dart")) {
+               for (sid = 0; sid < 256; sid++) {
+                       writel(DART_T8110_TCR_BYPASS_DART | 
DART_T8110_TCR_BYPASS_DAPF,
+                              base + DART_T8110_TCR(sid));
+                       writel(0, base + DART_T8110_TTBR(sid));
+               }
+       } else {
                for (sid = 0; sid < 16; sid++) {
                        writel(DART_TCR_BYPASS_DART | DART_TCR_BYPASS_DAPF,
                               base + DART_TCR(sid));
@@ -49,6 +64,7 @@ static int apple_dart_probe(struct udevice *dev)
 static const struct udevice_id apple_dart_ids[] = {
        { .compatible = "apple,t8103-dart" },
        { .compatible = "apple,t6000-dart" },
+       { .compatible = "apple,t8112-dart" },
        { /* sentinel */ }
 };
 
-- 
2.35.1