--- /dev/null
+From d9fae023fe86069750092fc1c2f3a73e2fb18512 Mon Sep 17 00:00:00 2001
+From: Michael Walle <michael@walle.cc>
+Date: Tue, 4 Apr 2023 18:21:29 +0100
+Subject: [PATCH] nvmem: layouts: sl28vpd: Add new layout driver
+
+This layout applies to the VPD of the Kontron sl28 boards. The VPD only
+contains a base MAC address. Therefore, we have to add an individual
+offset to it. This is done by taking the second argument of the nvmem
+phandle into account. Also this let us checking the VPD version and the
+checksum.
+
+Signed-off-by: Michael Walle <michael@walle.cc>
+Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
+Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
+Link: https://lore.kernel.org/r/20230404172148.82422-22-srinivas.kandagatla@linaro.org
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/nvmem/layouts/Kconfig | 9 ++
+ drivers/nvmem/layouts/Makefile | 2 +
+ drivers/nvmem/layouts/sl28vpd.c | 165 ++++++++++++++++++++++++++++++++
+ 3 files changed, 176 insertions(+)
+ create mode 100644 drivers/nvmem/layouts/sl28vpd.c
+
+--- a/drivers/nvmem/layouts/Kconfig
++++ b/drivers/nvmem/layouts/Kconfig
+@@ -2,4 +2,13 @@
+
+ menu "Layout Types"
+
++config NVMEM_LAYOUT_SL28_VPD
++ tristate "Kontron sl28 VPD layout support"
++ select CRC8
++ help
++ Say Y here if you want to support the VPD layout of the Kontron
++ SMARC-sAL28 boards.
++
++ If unsure, say N.
++
+ endmenu
+--- a/drivers/nvmem/layouts/Makefile
++++ b/drivers/nvmem/layouts/Makefile
+@@ -2,3 +2,5 @@
+ #
+ # Makefile for nvmem layouts.
+ #
++
++obj-$(CONFIG_NVMEM_LAYOUT_SL28_VPD) += sl28vpd.o
+--- /dev/null
++++ b/drivers/nvmem/layouts/sl28vpd.c
+@@ -0,0 +1,165 @@
++// SPDX-License-Identifier: GPL-2.0
++
++#include <linux/crc8.h>
++#include <linux/etherdevice.h>
++#include <linux/nvmem-consumer.h>
++#include <linux/nvmem-provider.h>
++#include <linux/of.h>
++#include <uapi/linux/if_ether.h>
++
++#define SL28VPD_MAGIC 'V'
++
++struct sl28vpd_header {
++ u8 magic;
++ u8 version;
++} __packed;
++
++struct sl28vpd_v1 {
++ struct sl28vpd_header header;
++ char serial_number[15];
++ u8 base_mac_address[ETH_ALEN];
++ u8 crc8;
++} __packed;
++
++static int sl28vpd_mac_address_pp(void *priv, const char *id, int index,
++ unsigned int offset, void *buf,
++ size_t bytes)
++{
++ if (bytes != ETH_ALEN)
++ return -EINVAL;
++
++ if (index < 0)
++ return -EINVAL;
++
++ if (!is_valid_ether_addr(buf))
++ return -EINVAL;
++
++ eth_addr_add(buf, index);
++
++ return 0;
++}
++
++static const struct nvmem_cell_info sl28vpd_v1_entries[] = {
++ {
++ .name = "serial-number",
++ .offset = offsetof(struct sl28vpd_v1, serial_number),
++ .bytes = sizeof_field(struct sl28vpd_v1, serial_number),
++ },
++ {
++ .name = "base-mac-address",
++ .offset = offsetof(struct sl28vpd_v1, base_mac_address),
++ .bytes = sizeof_field(struct sl28vpd_v1, base_mac_address),
++ .read_post_process = sl28vpd_mac_address_pp,
++ },
++};
++
++static int sl28vpd_v1_check_crc(struct device *dev, struct nvmem_device *nvmem)
++{
++ struct sl28vpd_v1 data_v1;
++ u8 table[CRC8_TABLE_SIZE];
++ int ret;
++ u8 crc;
++
++ crc8_populate_msb(table, 0x07);
++
++ ret = nvmem_device_read(nvmem, 0, sizeof(data_v1), &data_v1);
++ if (ret < 0)
++ return ret;
++ else if (ret != sizeof(data_v1))
++ return -EIO;
++
++ crc = crc8(table, (void *)&data_v1, sizeof(data_v1) - 1, 0);
++
++ if (crc != data_v1.crc8) {
++ dev_err(dev,
++ "Checksum is invalid (got %02x, expected %02x).\n",
++ crc, data_v1.crc8);
++ return -EINVAL;
++ }
++
++ return 0;
++}
++
++static int sl28vpd_add_cells(struct device *dev, struct nvmem_device *nvmem,
++ struct nvmem_layout *layout)
++{
++ const struct nvmem_cell_info *pinfo;
++ struct nvmem_cell_info info = {0};
++ struct device_node *layout_np;
++ struct sl28vpd_header hdr;
++ int ret, i;
++
++ /* check header */
++ ret = nvmem_device_read(nvmem, 0, sizeof(hdr), &hdr);
++ if (ret < 0)
++ return ret;
++ else if (ret != sizeof(hdr))
++ return -EIO;
++
++ if (hdr.magic != SL28VPD_MAGIC) {
++ dev_err(dev, "Invalid magic value (%02x)\n", hdr.magic);
++ return -EINVAL;
++ }
++
++ if (hdr.version != 1) {
++ dev_err(dev, "Version %d is unsupported.\n", hdr.version);
++ return -EINVAL;
++ }
++
++ ret = sl28vpd_v1_check_crc(dev, nvmem);
++ if (ret)
++ return ret;
++
++ layout_np = of_nvmem_layout_get_container(nvmem);
++ if (!layout_np)
++ return -ENOENT;
++
++ for (i = 0; i < ARRAY_SIZE(sl28vpd_v1_entries); i++) {
++ pinfo = &sl28vpd_v1_entries[i];
++
++ info.name = pinfo->name;
++ info.offset = pinfo->offset;
++ info.bytes = pinfo->bytes;
++ info.read_post_process = pinfo->read_post_process;
++ info.np = of_get_child_by_name(layout_np, pinfo->name);
++
++ ret = nvmem_add_one_cell(nvmem, &info);
++ if (ret) {
++ of_node_put(layout_np);
++ return ret;
++ }
++ }
++
++ of_node_put(layout_np);
++
++ return 0;
++}
++
++static const struct of_device_id sl28vpd_of_match_table[] = {
++ { .compatible = "kontron,sl28-vpd" },
++ {},
++};
++MODULE_DEVICE_TABLE(of, sl28vpd_of_match_table);
++
++struct nvmem_layout sl28vpd_layout = {
++ .name = "sl28-vpd",
++ .of_match_table = sl28vpd_of_match_table,
++ .add_cells = sl28vpd_add_cells,
++};
++
++static int __init sl28vpd_init(void)
++{
++ return nvmem_layout_register(&sl28vpd_layout);
++}
++
++static void __exit sl28vpd_exit(void)
++{
++ nvmem_layout_unregister(&sl28vpd_layout);
++}
++
++module_init(sl28vpd_init);
++module_exit(sl28vpd_exit);
++
++MODULE_LICENSE("GPL");
++MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
++MODULE_DESCRIPTION("NVMEM layout driver for the VPD of Kontron sl28 boards");
projects / openwrt / openwrt.git / blobdiff