mpc85xx: add SPI kernel loader for TP-Link TL-WDR4900 v1

Similar to the lzma-loader on our MIPS targets, the spi-loader acts as
a second-stage loader that will then load and start the actual kernel.
As the TL-WDR4900 uses SPI-NOR and the P1010 family does not have support
for memory mapping of this type of flash, this loader needs to contain a
basic driver for the FSL ESPI controller.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>

10 files changed, 426 insertions, 0 deletions

diff --git a/target/linux/mpc85xx/image/spi-loader/include/image.h b/target/linux/mpc85xx/image/spi-loader/include/image.h
new file mode 100644
index 0000000000..0377c2959e
--- /dev/null
+++ b/target/linux/mpc85xx/image/spi-loader/include/image.h
@@ -0,0 +1,61 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Derived from U-Boot include/image.h:
+ *
+ * (C) Copyright 2008 Semihalf
+ *
+ * (C) Copyright 2000-2005
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ ********************************************************************
+ * NOTE: This header file defines an interface to U-Boot. Including
+ * this (unmodified) header file in another file is considered normal
+ * use of U-Boot, and does *not* fall under the heading of "derived
+ * work".
+ ********************************************************************
+ */
+
+#pragma once
+
+#include <types.h>
+
+/*
+ * Compression Types
+ *
+ * The following are exposed to uImage header.
+ * New IDs *MUST* be appended at the end of the list and *NEVER*
+ * inserted for backward compatibility.
+ */
+enum {
+	IH_COMP_NONE		= 0,	/*  No	 Compression Used	*/
+	IH_COMP_GZIP,			/* gzip	 Compression Used	*/
+	IH_COMP_BZIP2,			/* bzip2 Compression Used	*/
+	IH_COMP_LZMA,			/* lzma  Compression Used	*/
+	IH_COMP_LZO,			/* lzo   Compression Used	*/
+	IH_COMP_LZ4,			/* lz4   Compression Used	*/
+	IH_COMP_ZSTD,			/* zstd   Compression Used	*/
+
+	IH_COMP_COUNT,
+};
+
+#define IH_MAGIC	0x27051956	/* Image Magic Number		*/
+#define IH_MAGIC_OKLI	0x4f4b4c49	/* 'OKLI' Magic Number */
+#define IH_NMLEN		32	/* Image Name Length		*/
+
+/*
+ * Legacy format image header,
+ * all data in network byte order (aka natural aka bigendian).
+ */
+typedef struct image_header {
+	uint32_t	ih_magic;	/* Image Header Magic Number	*/
+	uint32_t	ih_hcrc;	/* Image Header CRC Checksum	*/
+	uint32_t	ih_time;	/* Image Creation Timestamp	*/
+	uint32_t	ih_size;	/* Image Data Size		*/
+	uint32_t	ih_load;	/* Data	 Load  Address		*/
+	uint32_t	ih_ep;		/* Entry Point Address		*/
+	uint32_t	ih_dcrc;	/* Image Data CRC Checksum	*/
+	uint8_t		ih_os;		/* Operating System		*/
+	uint8_t		ih_arch;	/* CPU architecture		*/
+	uint8_t		ih_type;	/* Image Type			*/
+	uint8_t		ih_comp;	/* Compression Type		*/
+	uint8_t		ih_name[IH_NMLEN];	/* Image Name		*/
+} image_header_t;
diff --git a/target/linux/mpc85xx/image/spi-loader/include/init.h b/target/linux/mpc85xx/image/spi-loader/include/init.h
new file mode 100644
index 0000000000..f3a15f5d43
--- /dev/null
+++ b/target/linux/mpc85xx/image/spi-loader/include/init.h
@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: BSD-2-Clause
+/*
+ * Copyright (c) 2022 Matthias Schiffer <mschiffer@universe-factory.net>
+ */
+
+#pragma once
+
+void start(void);
diff --git a/target/linux/mpc85xx/image/spi-loader/include/io.h b/target/linux/mpc85xx/image/spi-loader/include/io.h
new file mode 100644
index 0000000000..d6eed5eee0
--- /dev/null
+++ b/target/linux/mpc85xx/image/spi-loader/include/io.h
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#pragma once
+
+#include <stdint.h>
+
+/*
+ * Low-level I/O routines.
+ *
+ * Copied from <file:arch/powerpc/include/asm/io.h> (which has no copyright)
+ */
+static inline uint8_t in_8(const volatile uint8_t *addr)
+{
+	int ret;
+
+	__asm__ __volatile__("lbz%U1%X1 %0,%1; twi 0,%0,0; isync"
+			     : "=r" (ret) : "m" (*addr));
+	return ret;
+}
+
+static inline void out_8(volatile uint8_t *addr, uint8_t val)
+{
+	__asm__ __volatile__("stb%U0%X0 %1,%0; sync"
+			     : "=m" (*addr) : "r" (val));
+}
+
+static inline uint16_t in_le16(const volatile uint16_t *addr)
+{
+	uint32_t ret;
+
+	__asm__ __volatile__("lhbrx %0,0,%1; twi 0,%0,0; isync"
+			     : "=r" (ret) : "r" (addr), "m" (*addr));
+
+	return ret;
+}
+
+static inline uint16_t in_be16(const volatile uint16_t *addr)
+{
+	uint32_t ret;
+
+	__asm__ __volatile__("lhz%U1%X1 %0,%1; twi 0,%0,0; isync"
+			     : "=r" (ret) : "m" (*addr));
+	return ret;
+}
+
+static inline void out_le16(volatile uint16_t *addr, uint16_t val)
+{
+	__asm__ __volatile__("sthbrx %1,0,%2; sync" : "=m" (*addr)
+			     : "r" (val), "r" (addr));
+}
+
+static inline void out_be16(volatile uint16_t *addr, uint16_t val)
+{
+	__asm__ __volatile__("sth%U0%X0 %1,%0; sync"
+			     : "=m" (*addr) : "r" (val));
+}
+
+static inline uint32_t in_le32(const volatile uint32_t *addr)
+{
+	uint32_t ret;
+
+	__asm__ __volatile__("lwbrx %0,0,%1; twi 0,%0,0; isync"
+			     : "=r" (ret) : "r" (addr), "m" (*addr));
+	return ret;
+}
+
+static inline uint32_t in_be32(const volatile uint32_t *addr)
+{
+	uint32_t ret;
+
+	__asm__ __volatile__("lwz%U1%X1 %0,%1; twi 0,%0,0; isync"
+			     : "=r" (ret) : "m" (*addr));
+	return ret;
+}
+
+static inline void out_le32(volatile uint32_t *addr, uint32_t val)
+{
+	__asm__ __volatile__("stwbrx %1,0,%2; sync" : "=m" (*addr)
+			     : "r" (val), "r" (addr));
+}
+
+static inline void out_be32(volatile uint32_t *addr, uint32_t val)
+{
+	__asm__ __volatile__("stw%U0%X0 %1,%0; sync"
+			     : "=m" (*addr) : "r" (val));
+}
+
+static inline void sync(void)
+{
+	asm volatile("sync" : : : "memory");
+}
+
+static inline void eieio(void)
+{
+	asm volatile("eieio" : : : "memory");
+}
+
+static inline void barrier(void)
+{
+	asm volatile("" : : : "memory");
+}
diff --git a/target/linux/mpc85xx/image/spi-loader/include/ppc_asm.h b/target/linux/mpc85xx/image/spi-loader/include/ppc_asm.h
new file mode 100644
index 0000000000..5dae34eb70
--- /dev/null
+++ b/target/linux/mpc85xx/image/spi-loader/include/ppc_asm.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#pragma once
+/*
+ *
+ * Definitions used by various bits of low-level assembly code on PowerPC.
+ *
+ * Copyright (C) 1995-1999 Gary Thomas, Paul Mackerras, Cort Dougan.
+ */
+
+/* Condition Register Bit Fields */
+
+#define	cr0	0
+#define	cr1	1
+#define	cr2	2
+#define	cr3	3
+#define	cr4	4
+#define	cr5	5
+#define	cr6	6
+#define	cr7	7
+
+/* General Purpose Registers (GPRs) */
+
+#define	r0	0
+#define	r1	1
+#define	r2	2
+#define	r3	3
+#define	r4	4
+#define	r5	5
+#define	r6	6
+#define	r7	7
+#define	r8	8
+#define	r9	9
+#define	r10	10
+#define	r11	11
+#define	r12	12
+#define	r13	13
+#define	r14	14
+#define	r15	15
+#define	r16	16
+#define	r17	17
+#define	r18	18
+#define	r19	19
+#define	r20	20
+#define	r21	21
+#define	r22	22
+#define	r23	23
+#define	r24	24
+#define	r25	25
+#define	r26	26
+#define	r27	27
+#define	r28	28
+#define	r29	29
+#define	r30	30
+#define	r31	31
diff --git a/target/linux/mpc85xx/image/spi-loader/include/serial.h b/target/linux/mpc85xx/image/spi-loader/include/serial.h
new file mode 100644
index 0000000000..1d80ede335
--- /dev/null
+++ b/target/linux/mpc85xx/image/spi-loader/include/serial.h
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: BSD-2-Clause
+
+#pragma once
+
+int serial_console_getchar(void);
+int serial_console_tstc(void);
+void serial_console_putchar(char c);
+void serial_console_init(void);
+
diff --git a/target/linux/mpc85xx/image/spi-loader/include/spi-nor.h b/target/linux/mpc85xx/image/spi-loader/include/spi-nor.h
new file mode 100644
index 0000000000..efbf386601
--- /dev/null
+++ b/target/linux/mpc85xx/image/spi-loader/include/spi-nor.h
@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: BSD-2-Clause
+/*
+ * Copyright (c) 2022 Matthias Schiffer <mschiffer@universe-factory.net>
+ */
+
+#pragma once
+
+#include <types.h>
+
+int spi_nor_read_id(void);
+int spi_nor_read_data(void *dest, size_t pos, size_t len);
diff --git a/target/linux/mpc85xx/image/spi-loader/include/spi.h b/target/linux/mpc85xx/image/spi-loader/include/spi.h
new file mode 100644
index 0000000000..98e799ccaf
--- /dev/null
+++ b/target/linux/mpc85xx/image/spi-loader/include/spi.h
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Common SPI Interface: Controller-specific definitions
+ *
+ * Copyright (c) 2022 Matthias Schiffer <mschiffer@universe-factory.net>
+ *
+ * Based on U-boot's spi.h:
+ *
+ * (C) Copyright 2001
+ * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
+ */
+
+#pragma once
+
+#include <types.h>
+
+/* SPI mode flags */
+#define SPI_CPHA	BIT(0)	/* clock phase (1 = SPI_CLOCK_PHASE_SECOND) */
+#define SPI_CPOL	BIT(1)	/* clock polarity (1 = SPI_POLARITY_HIGH) */
+#define SPI_MODE_0	(0|0)			/* (original MicroWire) */
+#define SPI_MODE_1	(0|SPI_CPHA)
+#define SPI_MODE_2	(SPI_CPOL|0)
+#define SPI_MODE_3	(SPI_CPOL|SPI_CPHA)
+
+struct spi_transfer {
+	const void *tx_buf;
+	void *rx_buf;
+	size_t len;
+};
+
+static inline size_t spi_message_len(const struct spi_transfer *msg, int n) {
+	size_t total = 0;
+	for (int i = 0; i < n; i++) {
+		total += msg[i].len;
+	}
+	return total;
+}
+
+int spi_init(unsigned int cs, unsigned int max_hz, unsigned int mode);
+int spi_claim_bus(void);
+void spi_release_bus(void);
+int spi_xfer(const struct spi_transfer *msg, int n);
+size_t spi_max_xfer(void);
diff --git a/target/linux/mpc85xx/image/spi-loader/include/stdio.h b/target/linux/mpc85xx/image/spi-loader/include/stdio.h
new file mode 100644
index 0000000000..60494300b2
--- /dev/null
+++ b/target/linux/mpc85xx/image/spi-loader/include/stdio.h
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: BSD-2-Clause
+/*
+ * Copyright (c) 2022 Matthias Schiffer <mschiffer@universe-factory.net>
+ */
+
+#pragma once
+
+#include <serial.h>
+#include <types.h>
+
+static inline int getchar(void)
+{
+	return serial_console_getchar();
+}
+
+static inline int tstc(void)
+{
+	return serial_console_tstc();
+}
+
+static inline int putchar(char c)
+{
+	if (c == '\n')
+		serial_console_putchar('\r');
+	serial_console_putchar(c);
+	return 0;
+}
+
+int puts(const char *s);
+
+/* Utility functions */
+void put_u4(uint8_t v);
+void put_u8(uint8_t v);
+void put_u16(uint16_t v);
+void put_u32(uint32_t v);
+void put_ptr(const void *p);
+void put_array(const void *p, size_t l);
+
+#define put_with_label(label, put, value) do { \
+		puts(label); \
+		put(value); \
+		puts("\n"); \
+	} while (0)
diff --git a/target/linux/mpc85xx/image/spi-loader/include/string.h b/target/linux/mpc85xx/image/spi-loader/include/string.h
new file mode 100644
index 0000000000..f9e6fed38d
--- /dev/null
+++ b/target/linux/mpc85xx/image/spi-loader/include/string.h
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#pragma once
+
+#include <stddef.h>
+
+extern char *strcpy(char *dest, const char *src);
+extern char *strncpy(char *dest, const char *src, size_t n);
+extern char *strcat(char *dest, const char *src);
+extern char *strchr(const char *s, int c);
+extern char *strrchr(const char *s, int c);
+extern int strcmp(const char *s1, const char *s2);
+extern int strncmp(const char *s1, const char *s2, size_t n);
+extern size_t strlen(const char *s);
+extern size_t strnlen(const char *s, size_t count);
+
+extern void *memset(void *s, int c, size_t n);
+extern void *memmove(void *dest, const void *src, unsigned long n);
+extern void *memcpy(void *dest, const void *src, unsigned long n);
+extern void *memchr(const void *s, int c, size_t n);
+extern int memcmp(const void *s1, const void *s2, size_t n);
+
+extern void flush_cache(void *, unsigned long);
diff --git a/target/linux/mpc85xx/image/spi-loader/include/types.h b/target/linux/mpc85xx/image/spi-loader/include/types.h
new file mode 100644
index 0000000000..b80f9e625c
--- /dev/null
+++ b/target/linux/mpc85xx/image/spi-loader/include/types.h
@@ -0,0 +1,72 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Code originates from Linux kernel arch/powerpc/boot
+ * (types.h, swab.h, of.h)
+ */
+
+#pragma once
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+
+#define BIT(nr)	(1UL << (nr))
+
+#define min(x,y) ({ \
+	typeof(x) _x = (x);	\
+	typeof(y) _y = (y);	\
+	(void) (&_x == &_y);	\
+	_x < _y ? _x : _y; })
+
+#define max(x,y) ({ \
+	typeof(x) _x = (x);	\
+	typeof(y) _y = (y);	\
+	(void) (&_x == &_y);	\
+	_x > _y ? _x : _y; })
+
+#define min_t(type, a, b) min(((type) a), ((type) b))
+#define max_t(type, a, b) max(((type) a), ((type) b))
+
+static inline uint16_t swab16(uint16_t x)
+{
+	return  ((x & (uint16_t)0x00ffU) << 8) |
+		((x & (uint16_t)0xff00U) >> 8);
+}
+
+static inline uint32_t swab32(uint32_t x)
+{
+	return  ((x & (uint32_t)0x000000ffUL) << 24) |
+		((x & (uint32_t)0x0000ff00UL) <<  8) |
+		((x & (uint32_t)0x00ff0000UL) >>  8) |
+		((x & (uint32_t)0xff000000UL) >> 24);
+}
+
+static inline uint64_t swab64(uint64_t x)
+{
+	return  (uint64_t)((x & (uint64_t)0x00000000000000ffULL) << 56) |
+		(uint64_t)((x & (uint64_t)0x000000000000ff00ULL) << 40) |
+		(uint64_t)((x & (uint64_t)0x0000000000ff0000ULL) << 24) |
+		(uint64_t)((x & (uint64_t)0x00000000ff000000ULL) <<  8) |
+		(uint64_t)((x & (uint64_t)0x000000ff00000000ULL) >>  8) |
+		(uint64_t)((x & (uint64_t)0x0000ff0000000000ULL) >> 24) |
+		(uint64_t)((x & (uint64_t)0x00ff000000000000ULL) >> 40) |
+		(uint64_t)((x & (uint64_t)0xff00000000000000ULL) >> 56);
+}
+
+#ifdef __LITTLE_ENDIAN__
+#define cpu_to_be16(x) swab16(x)
+#define be16_to_cpu(x) swab16(x)
+#define cpu_to_be32(x) swab32(x)
+#define be32_to_cpu(x) swab32(x)
+#define cpu_to_be64(x) swab64(x)
+#define be64_to_cpu(x) swab64(x)
+#else
+#define cpu_to_be16(x) (x)
+#define be16_to_cpu(x) (x)
+#define cpu_to_be32(x) (x)
+#define be32_to_cpu(x) (x)
+#define cpu_to_be64(x) (x)
+#define be64_to_cpu(x) (x)
+#endif