bcm27xx: add support for linux v5.15

Build system: x86_64
Build-tested: bcm2708, bcm2709, bcm2710, bcm2711
Run-tested: bcm2708/RPiB+, bcm2709/RPi3B, bcm2710/RPi3B, bcm2711/RPi4B

Signed-off-by: Marty Jones <mj8263788@gmail.com>
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-5.15/950-0301-bcm2835-dma-only-reserve-channel-0-if-legacy-dma-dri.patch b/target/linux/bcm27xx/patches-5.15/950-0301-bcm2835-dma-only-reserve-channel-0-if-legacy-dma-dri.patch
new file mode 100644
index 0000000000..d21dacb43c
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.15/950-0301-bcm2835-dma-only-reserve-channel-0-if-legacy-dma-dri.patch
@@ -0,0 +1,32 @@
+From 89036f62b573bc2df30e7b865da65454213f6720 Mon Sep 17 00:00:00 2001
+From: Matthias Reichl <hias@horus.com>
+Date: Sun, 11 Oct 2020 00:48:55 +0200
+Subject: [PATCH] bcm2835-dma: only reserve channel 0 if legacy dma
+ driver is enabled
+
+If CONFIG_DMA_BCM2708 isn't enabled there's no need to mask out
+one of the already scarce DMA channels.
+
+Signed-off-by: Matthias Reichl <hias@horus.com>
+---
+ drivers/dma/bcm2835-dma.c | 2 ++
+ 1 file changed, 2 insertions(+)
+
+--- a/drivers/dma/bcm2835-dma.c
++++ b/drivers/dma/bcm2835-dma.c
+@@ -1283,6 +1283,7 @@ static int bcm2835_dma_probe(struct plat
+ 		goto err_no_dma;
+ 	}
+ 
++#ifdef CONFIG_DMA_BCM2708
+ 	/* One channel is reserved for the legacy API */
+ 	if (chans_available & BCM2835_DMA_BULK_MASK) {
+ 		rc = bcm_dmaman_probe(pdev, base,
+@@ -1293,6 +1294,7 @@ static int bcm2835_dma_probe(struct plat
+ 
+ 		chans_available &= ~BCM2835_DMA_BULK_MASK;
+ 	}
++#endif
+ 
+ 	/* And possibly one for the 40-bit DMA memcpy API */
+ 	if (chans_available & od->cfg_data->chan_40bit_mask &