From f32085fc0b87049491b07e198d924d738a1a2834 Mon Sep 17 00:00:00 2001
From: Daniel Danzberger <daniel@dd-wrt.com>
Date: Wed, 3 Aug 2022 17:31:03 +0200
Subject: [PATCH] mtd: spinand: Add support for Etron EM73D044VCx

Airoha is a new ARM platform based on Cortex-A53 which has recently been
merged into linux-next.

Due to BootROM limitations on this platform, the Cortex-A53 can't run in
Aarch64 mode and code must be compiled for 32-Bit ARM.

This support is based mostly on those linux-next commits backported
for kernel 5.15.

Patches:
1 - platform support = linux-next
2 - clock driver = linux-next
3 - gpio driver = linux-next
4 - linux,usable-memory-range dts support = linux-next
5 - mtd spinand driver
6 - spi driver
7 - pci driver (kconfig only, uses mediatek PCI) = linux-next

Still missing:
- Ethernet driver
- Sysupgrade support

A.t.m there exists one subtarget EN7523 with only one evaluation
board.

The initramfs can be run with the following commands from u-boot:
-
u-boot> setenv bootfile \
	librecmc-airoha-airoha_en7523-evb-initramfs-kernel.bin
u-boot> tftpboot
u-boot> bootm 0x81800000
-

Submitted-by: Daniel Danzberger <daniel@dd-wrt.com>

--- a/drivers/mtd/nand/spi/Makefile
+++ b/drivers/mtd/nand/spi/Makefile
@@ -1,3 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0
-spinand-objs := core.o esmt.o gigadevice.o macronix.o micron.o paragon.o toshiba.o winbond.o xtx.o
+spinand-objs := core.o esmt.o etron.o gigadevice.o macronix.o micron.o paragon.o toshiba.o winbond.o xtx.o
 obj-$(CONFIG_MTD_SPI_NAND) += spinand.o
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -908,6 +908,7 @@ static const struct nand_ops spinand_ops
 static const struct spinand_manufacturer *spinand_manufacturers[] = {
 	&esmt_c8_spinand_manufacturer,
 	&gigadevice_spinand_manufacturer,
+	&etron_spinand_manufacturer,
 	&macronix_spinand_manufacturer,
 	&micron_spinand_manufacturer,
 	&paragon_spinand_manufacturer,
--- /dev/null
+++ b/drivers/mtd/nand/spi/etron.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/mtd/spinand.h>
+
+#define SPINAND_MFR_ETRON			0xd5
+
+
+static SPINAND_OP_VARIANTS(read_cache_variants,
+		SPINAND_PAGE_READ_FROM_CACHE_QUADIO_OP(0, 1, NULL, 0),
+		SPINAND_PAGE_READ_FROM_CACHE_X4_OP(0, 1, NULL, 0),
+		SPINAND_PAGE_READ_FROM_CACHE_DUALIO_OP(0, 1, NULL, 0),
+		SPINAND_PAGE_READ_FROM_CACHE_X2_OP(0, 1, NULL, 0),
+		SPINAND_PAGE_READ_FROM_CACHE_OP(true, 0, 1, NULL, 0),
+		SPINAND_PAGE_READ_FROM_CACHE_OP(false, 0, 1, NULL, 0));
+
+static SPINAND_OP_VARIANTS(write_cache_variants,
+		SPINAND_PROG_LOAD_X4(true, 0, NULL, 0),
+		SPINAND_PROG_LOAD(true, 0, NULL, 0));
+
+static SPINAND_OP_VARIANTS(update_cache_variants,
+		SPINAND_PROG_LOAD_X4(false, 0, NULL, 0),
+		SPINAND_PROG_LOAD(false, 0, NULL, 0));
+
+static int etron_ooblayout_ecc(struct mtd_info *mtd, int section,
+					struct mtd_oob_region *oobregion)
+{
+	if (section)
+		return -ERANGE;
+
+	oobregion->offset = 72;
+	oobregion->length = 56;
+
+	return 0;
+}
+
+static int etron_ooblayout_free(struct mtd_info *mtd, int section,
+			   struct mtd_oob_region *oobregion)
+{
+	if (section)
+		return -ERANGE;
+
+	oobregion->offset = 1;
+	oobregion->length = 71;
+
+	return 0;
+}
+
+static int etron_ecc_get_status(struct spinand_device *spinand, u8 status)
+{
+	switch (status & STATUS_ECC_MASK) {
+	case STATUS_ECC_NO_BITFLIPS:
+		return 0;
+
+	case STATUS_ECC_HAS_BITFLIPS:
+		/* Between 1-7 bitflips were corrected */
+		return 7;
+
+	case STATUS_ECC_MASK:
+		/* Maximum bitflips were corrected */
+		return 8;
+
+	case STATUS_ECC_UNCOR_ERROR:
+		return -EBADMSG;
+	}
+
+	return -EINVAL;
+}
+
+static const struct mtd_ooblayout_ops etron_ooblayout = {
+	.ecc = etron_ooblayout_ecc,
+	.free = etron_ooblayout_free,
+};
+
+static const struct spinand_info etron_spinand_table[] = {
+	SPINAND_INFO("EM73D044VCx",
+		     SPINAND_ID(SPINAND_READID_METHOD_OPCODE_ADDR, 0x1f),
+		     // bpc, pagesize, oobsize, pagesperblock, bperlun, maxbadplun, ppl, lpt, #t
+		     NAND_MEMORG(1, 2048, 128, 64, 2048, 40, 1, 1, 1),
+		     NAND_ECCREQ(8, 512),
+		     SPINAND_INFO_OP_VARIANTS(&read_cache_variants,
+					      &write_cache_variants,
+					      &update_cache_variants),
+		     SPINAND_HAS_QE_BIT,
+		     SPINAND_ECCINFO(&etron_ooblayout, etron_ecc_get_status)),
+};
+
+static const struct spinand_manufacturer_ops etron_spinand_manuf_ops = {
+};
+
+const struct spinand_manufacturer etron_spinand_manufacturer = {
+	.id = SPINAND_MFR_ETRON,
+	.name = "Etron",
+	.chips = etron_spinand_table,
+	.nchips = ARRAY_SIZE(etron_spinand_table),
+	.ops = &etron_spinand_manuf_ops,
+};
--- a/include/linux/mtd/spinand.h
+++ b/include/linux/mtd/spinand.h
@@ -261,6 +261,7 @@ struct spinand_manufacturer {
 
 /* SPI NAND manufacturers */
 extern const struct spinand_manufacturer esmt_c8_spinand_manufacturer;
+extern const struct spinand_manufacturer etron_spinand_manufacturer;
 extern const struct spinand_manufacturer gigadevice_spinand_manufacturer;
 extern const struct spinand_manufacturer macronix_spinand_manufacturer;
 extern const struct spinand_manufacturer micron_spinand_manufacturer;
