[v3,17/20] nvmem: layouts: sl28vpd: Add new layout driver
Commit Message
From: Michael Walle <michael@walle.cc>
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>
---
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
Comments
On 08/03/2023 15:31, Miquel Raynal wrote:
> +
> +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);
Looking at this pattern in two drivers, we could come up with some
helper macro like.
#define module_nvmem_layout_driver(__layout_driver) \
module_driver(__layout_driver, nvmem_layout_register, \
nvmem_layout_unregister)
--srini
Hi Srinivas,
srinivas.kandagatla@linaro.org wrote on Fri, 10 Mar 2023 11:03:45 +0000:
> On 08/03/2023 15:31, Miquel Raynal wrote:
> > +
> > +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);
> Looking at this pattern in two drivers, we could come up with some helper macro like.
>
> #define module_nvmem_layout_driver(__layout_driver) \
> module_driver(__layout_driver, nvmem_layout_register, \
> nvmem_layout_unregister)
Nice idea! I will make a patch; is it okay do it on top?
Thanks,
Miquèl
On 10/03/2023 11:16, Miquel Raynal wrote:
> Hi Srinivas,
>
> srinivas.kandagatla@linaro.org wrote on Fri, 10 Mar 2023 11:03:45 +0000:
>
>> On 08/03/2023 15:31, Miquel Raynal wrote:
>>> +
>>> +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);
>> Looking at this pattern in two drivers, we could come up with some helper macro like.
>>
>> #define module_nvmem_layout_driver(__layout_driver) \
>> module_driver(__layout_driver, nvmem_layout_register, \
>> nvmem_layout_unregister)
>
> Nice idea! I will make a patch; is it okay do it on top?
sounds good
--srini
>
> Thanks,
> Miquèl
@@ -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
@@ -2,3 +2,5 @@
#
# Makefile for nvmem layouts.
#
+
+obj-$(CONFIG_NVMEM_LAYOUT_SL28_VPD) += sl28vpd.o
new file mode 100644
@@ -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");