powerpc: mpc885: Add CPM USB-SOF microcode for CPM15 ERRATA

MPC885 CPU has the following ERRATA:

	When the USB controller is configured in Host mode, and the
	SOF generation (SFTE=1 in USMOD register) is being used,
	there may be false CRC error indication in other SCCs.
	Although the data is received correctly, the CRC result
	will be corrupted.

Add capability to load the related microcode to fix it.
The microcode binary data is copied from Linux kernel.

Other microcode will be added in following patch so make it
a Kconfig choice.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>

3 files changed, 64 insertions, 0 deletions

diff --git a/arch/powerpc/cpu/mpc8xx/Kconfig b/arch/powerpc/cpu/mpc8xx/Kconfig
index bfd903bc107..52caf06aac9 100644
--- a/arch/powerpc/cpu/mpc8xx/Kconfig
+++ b/arch/powerpc/cpu/mpc8xx/Kconfig
@@ -30,6 +30,31 @@ config MPC885
 
 endchoice
 
+choice
+	prompt "Microcode patch selection"
+	default NO_UCODE_PATCH
+	help
+	  This allows loading of CPM microcode.
+
+	  Only one microcode can be loaded at a time.
+
+config NO_UCODE_PATCH
+	bool "None"
+
+config USB_SOF_UCODE_PATCH
+	bool "USB SOF patch"
+	depends on MPC885
+	help
+	  This microcode fixes CPM15 errata:
+
+	  When the USB controller is configured in Host mode, and the
+	  SOF generation (SFTE=1 in USMOD register) is being used,
+	  there may be false CRC error indication in other SCCs.
+	  Although the data is received correctly, the CRC result
+	  will be corrupted.
+
+endchoice
+
 comment "Specific commands"
 
 config CMD_IMMAP
diff --git a/arch/powerpc/cpu/mpc8xx/Makefile b/arch/powerpc/cpu/mpc8xx/Makefile
index 8918a26288f..5a6561e0247 100644
--- a/arch/powerpc/cpu/mpc8xx/Makefile
+++ b/arch/powerpc/cpu/mpc8xx/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_CMD_IMMAP) += immap.o
 obj-y	+= interrupts.o
 obj-y	+= speed.o
 obj-y	+= cache.o
+obj-$(CONFIG_USB_SOF_UCODE_PATCH) += micropatch_usb_sof.o
diff --git a/arch/powerpc/cpu/mpc8xx/micropatch_usb_sof.c b/arch/powerpc/cpu/mpc8xx/micropatch_usb_sof.c
new file mode 100644
index 00000000000..7fc640df90a
--- /dev/null
+++ b/arch/powerpc/cpu/mpc8xx/micropatch_usb_sof.c
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Microcode patches for the CPM as supplied by Motorola.
+ */
+
+#include <linux/string.h>
+#include <linux/io.h>
+#include <asm/immap_8xx.h>
+#include <asm/cpm_8xx.h>
+
+/*
+ *  USB SOF patch arrays.
+ */
+static uint patch_2000[] = {
+	0x7fff0000, 0x7ffd0000, 0x7ffb0000, 0x49f7ba5b,
+	0xba383ffb, 0xf9b8b46d, 0xe5ab4e07, 0xaf77bffe,
+	0x3f7bbf79, 0xba5bba38, 0xe7676076, 0x60750000
+};
+
+static uint patch_2f00[] = {
+	0x3030304c, 0xcab9e441, 0xa1aaf220
+};
+
+void cpm_load_patch(cpm8xx_t __iomem *cp)
+{
+	out_be16(&cp->cp_rccr, 0);
+
+	memcpy_toio(cp->cp_dpmem, patch_2000, sizeof(patch_2000));
+	memcpy_toio(cp->cp_dpmem + 0xf00, patch_2f00, sizeof(patch_2f00));
+
+	out_be16(&cp->cp_cpmcr1, 0);
+	out_be16(&cp->cp_cpmcr2, 0);
+	out_be16(&cp->cp_cpmcr3, 0);
+	out_be16(&cp->cp_cpmcr4, 0);
+
+	out_be16(&cp->cp_rccr, 9);
+}