ARM: rpi: support PBL use of mbox

barebox uses DT to find out the base address of the mailbox. For the
generic image, we need to use the mailbox interface to find out which DT
to use. Resolve the chicken-egg problem by hardcoding a list of mailbox
base addresses and selecting the correct one by looking up the CPU ID
and using that to deduce the Raspberry Pi SoC type.

Note that this is incompatible with arm_peri_high=1.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Link: https://lore.barebox.org/20220609055922.667016-5-a.fatoum@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 16 insertions, 8 deletions

diff --git a/arch/arm/mach-bcm283x/mbox.c b/arch/arm/mach-bcm283x/mbox.c
index 4b14afcfe4..b77065ab30 100644
--- a/arch/arm/mach-bcm283x/mbox.c
+++ b/arch/arm/mach-bcm283x/mbox.c
@@ -14,13 +14,20 @@
 #include <init.h>
 #include <io.h>
 #include <of_address.h>
+#include <pbl.h>
 
 #include <mach/mbox.h>
+#include <mach/core.h>
 
 #define TIMEOUT (MSECOND * 1000)
 
 static void __iomem *mbox_base;
 
+#ifdef __PBL__
+#define is_timeout_non_interruptible(start, timeout) ((void)start, 0)
+#define get_time_ns() 0
+#endif
+
 static int bcm2835_mbox_call_raw(u32 chan, struct bcm2835_mbox_hdr *buffer,
 					u32 *recv)
 {
@@ -109,19 +116,20 @@ static void dump_buf(struct bcm2835_mbox_hdr *buffer)
 }
 #endif
 
-static int bcm2835_mbox_probe(void)
+static void __iomem *bcm2835_mbox_probe(void)
 {
 	struct device_node *mbox_node;
 
+	if (IN_PBL)
+		return bcm2835_get_mmio_base_by_cpuid() + 0xb880;
+
 	mbox_node = of_find_compatible_node(NULL, NULL, "brcm,bcm2835-mbox");
 	if (!mbox_node) {
 		pr_err("Missing mbox node\n");
-		return -ENOENT;
+		return NULL;
 	}
 
-	mbox_base = of_iomap(mbox_node, 0);
-
-	return 0;
+	return of_iomap(mbox_node, 0);
 }
 
 int bcm2835_mbox_call_prop(u32 chan, struct bcm2835_mbox_hdr *buffer)
@@ -132,9 +140,9 @@ int bcm2835_mbox_call_prop(u32 chan, struct bcm2835_mbox_hdr *buffer)
 	int tag_index;
 
 	if (!mbox_base) {
-		ret = bcm2835_mbox_probe();
-		if (ret)
-			return ret;
+		mbox_base = bcm2835_mbox_probe();
+		if (!mbox_base)
+			return -ENOENT;
 	}
 
 	pr_debug("mbox: TX buffer\n");