mediatek: add driver for Adtran MFGINFO NVMEM layout

This driver allows retrieving MAC addresses and other factory information
via the NVMEM framework on Adtran devices.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

target/linux/mediatek/filogic/config-6.6

@@ -313,6 +313,7 @@ CONFIG_NR_CPUS=4
 CONFIG_NVMEM=y
 CONFIG_NVMEM_BLOCK=y
 CONFIG_NVMEM_LAYOUTS=y
+CONFIG_NVMEM_LAYOUT_ADTRAN=y
 CONFIG_NVMEM_MTK_EFUSE=y
 CONFIG_NVMEM_SYSFS=y
 CONFIG_OF=y

target/linux/mediatek/mt7622/config-6.6

@@ -314,7 +314,9 @@ CONFIG_NO_HZ_COMMON=y
 CONFIG_NO_HZ_IDLE=y
 CONFIG_NR_CPUS=2
 CONFIG_NVMEM=y
+CONFIG_NVMEM_BLOCK=y
 CONFIG_NVMEM_LAYOUTS=y
+CONFIG_NVMEM_LAYOUT_ADTRAN=y
 CONFIG_NVMEM_MTK_EFUSE=y
 CONFIG_NVMEM_SYSFS=y
 CONFIG_OF=y

target/linux/mediatek/mt7623/config-6.6

@@ -436,6 +436,7 @@ CONFIG_NO_HZ_IDLE=y
 CONFIG_NR_CPUS=4
 CONFIG_NVMEM=y
 CONFIG_NVMEM_LAYOUTS=y
+# CONFIG_NVMEM_LAYOUT_ADTRAN is not set
 CONFIG_NVMEM_MTK_EFUSE=y
 # CONFIG_NVMEM_SPMI_SDAM is not set
 CONFIG_NVMEM_SYSFS=y

target/linux/mediatek/mt7629/config-6.6

@@ -239,6 +239,7 @@ CONFIG_NO_HZ_IDLE=y
 CONFIG_NR_CPUS=2
 CONFIG_NVMEM=y
 CONFIG_NVMEM_LAYOUTS=y
+# CONFIG_NVMEM_LAYOUT_ADTRAN is not set
 # CONFIG_NVMEM_MTK_EFUSE is not set
 CONFIG_NVMEM_SYSFS=y
 CONFIG_OF=y

target/linux/mediatek/patches-6.6/450-nvmem-add-layout-for-Adtran-devices.patch

@@ -0,0 +1,191 @@
+From c22bc82183c2dea64919f975473ec518738baa3e Mon Sep 17 00:00:00 2001
+From: Daniel Golle <daniel@makrotopia.org>
+Date: Wed, 12 Jul 2023 13:38:35 +0100
+Subject: [PATCH] nvmem: add layout for Adtran devices
+
+Adtran stores unique factory data on GPT partitions on the eMMC.
+Using blk-nvmem the 'mfginfo' partition gets exposes as NVMEM provider.
+
+Add layout driver to parse mfginfo, mainly to provide MAC addresses to
+Ethernet and wireless interfaces.
+
+Variable names are converted to lower-case and '_' is replaced with '-'
+in order to comply with the device tree node naming convention.
+The main MAC address always ends on a 0 and up to 16 addresses are
+alocated for each device to use for various interfaces.
+
+Implement post-processing function for 'MFG_MAC' variable ('mfg-mac'
+node name in device tree) adding the nvmem cell index to the least
+significant digit of the MAC address.
+
+Signed-off-by: Daniel Golle <daniel@makrotopia.org>
+---
+ drivers/nvmem/layouts/Kconfig  |   9 +++
+ drivers/nvmem/layouts/Makefile |   1 +
+ drivers/nvmem/layouts/adtran.c | 135 +++++++++++++++++++++++++++++++++
+ 3 files changed, 145 insertions(+)
+ create mode 100644 drivers/nvmem/layouts/adtran.c
+
+--- a/drivers/nvmem/layouts/Kconfig
++++ b/drivers/nvmem/layouts/Kconfig
+@@ -8,6 +8,15 @@ if NVMEM_LAYOUTS
+ 
+ menu "Layout Types"
+ 
++config NVMEM_LAYOUT_ADTRAN
++	tristate "Adtran mfginfo layout support"
++	select GENERIC_NET_UTILS
++	help
++	  Say Y here if you want to support the layout used by Adtran for
++	  mfginfo.
++
++	  If unsure, say N.
++
+ config NVMEM_LAYOUT_SL28_VPD
+ 	tristate "Kontron sl28 VPD layout support"
+ 	select CRC8
+--- a/drivers/nvmem/layouts/Makefile
++++ b/drivers/nvmem/layouts/Makefile
+@@ -6,3 +6,4 @@
+ obj-$(CONFIG_NVMEM_LAYOUT_SL28_VPD) += sl28vpd.o
+ obj-$(CONFIG_NVMEM_LAYOUT_ONIE_TLV) += onie-tlv.o
+ obj-$(CONFIG_NVMEM_LAYOUT_U_BOOT_ENV) += u-boot-env.o
++obj-$(CONFIG_NVMEM_LAYOUT_ADTRAN) += adtran.o
+--- /dev/null
++++ b/drivers/nvmem/layouts/adtran.c
+@@ -0,0 +1,135 @@
++// SPDX-License-Identifier: GPL-2.0
++#include <linux/ctype.h>
++#include <linux/etherdevice.h>
++#include <linux/nvmem-consumer.h>
++#include <linux/nvmem-provider.h>
++#include <linux/of.h>
++#include <linux/platform_device.h>
++
++/*
++ * Adtran devices usually come with a main MAC address ending on 0 and
++ * hence may have up to 16 MAC addresses per device.
++ * The main MAC address is stored as variable MFG_MAC in ASCII format.
++ */
++static int adtran_mac_address_pp(void *priv, const char *id, int index,
++				  unsigned int offset, void *buf,
++				  size_t bytes)
++{
++	u8 mac[ETH_ALEN];
++
++	if (WARN_ON(bytes != 3 * ETH_ALEN - 1))
++		return -EINVAL;
++
++	if (!mac_pton(buf, mac))
++		return -EINVAL;
++
++	if (index)
++		eth_addr_add(mac, index);
++
++	ether_addr_copy(buf, mac);
++
++	return 0;
++}
++
++static int adtran_add_cells(struct nvmem_layout *layout)
++{
++	struct nvmem_device *nvmem = layout->nvmem;
++	struct nvmem_cell_info info;
++	struct device_node *layout_np;
++	char mfginfo[1024], *c, *t, *p;
++	int ret = -EINVAL;
++
++	ret = nvmem_device_read(nvmem, 0, sizeof(mfginfo), mfginfo);
++	if (ret < 0)
++		return ret;
++	else if (ret != sizeof(mfginfo))
++		return -EIO;
++
++	layout_np = of_nvmem_layout_get_container(nvmem);
++	if (!layout_np)
++		return -ENOENT;
++
++	c = mfginfo;
++	while (*c != 0xff) {
++		memset(&info, 0, sizeof(info));
++		if (*c == '#')
++			goto nextline;
++
++		t = strchr(c, '=');
++		if (!t)
++			goto nextline;
++
++		*t = '\0';
++		++t;
++		info.offset = t - mfginfo;
++		/* process variable name: convert to lower-case, '_' -> '-' */
++		p = c;
++		do {
++			*p = tolower(*p);
++			if (*p == '_')
++				*p = '-';
++		} while (*++p);
++		info.name = c;
++		c = strchr(t, 0xa); /* find newline */
++		if (!c)
++			break;
++
++		info.bytes = c - t;
++		if (!strcmp(info.name, "mfg-mac")) {
++			info.raw_len = info.bytes;
++			info.bytes = ETH_ALEN;
++			info.read_post_process = adtran_mac_address_pp;
++		}
++
++		info.np = of_get_child_by_name(layout_np, info.name);
++		ret = nvmem_add_one_cell(nvmem, &info);
++		if (ret)
++			break;
++
++		++c;
++		continue;
++
++nextline:
++		c = strchr(c, 0xa); /* find newline */
++		if (!c)
++			break;
++		++c;
++	}
++
++	of_node_put(layout_np);
++
++	return ret;
++}
++
++static int adtran_probe(struct nvmem_layout *layout)
++{
++	layout->add_cells = adtran_add_cells;
++
++	return nvmem_layout_register(layout);
++}
++
++static void adtran_remove(struct nvmem_layout *layout)
++{
++	nvmem_layout_unregister(layout);
++}
++
++static const struct of_device_id adtran_of_match_table[] = {
++	{ .compatible = "adtran,mfginfo" },
++	{},
++};
++MODULE_DEVICE_TABLE(of, adtran_of_match_table);
++
++static struct nvmem_layout_driver adtran_layout = {
++	.driver = {
++		.owner = THIS_MODULE,
++		.name = "adtran-layout",
++		.of_match_table = adtran_of_match_table,
++	},
++	.probe = adtran_probe,
++	.remove = adtran_remove,
++};
++module_nvmem_layout_driver(adtran_layout);
++
++MODULE_LICENSE("GPL");
++MODULE_AUTHOR("Daniel Golle <daniel@makrotopia.org>");
++MODULE_DESCRIPTION("NVMEM layout driver for Adtran mfginfo");