[PATCH v10 1/4] nvmem: prepare basics for FRAM support

From: Jiri Prchal
Date: Fri Jun 11 2021 - 05:46:13 EST


Added enum and string for FRAM (ferroelectric RAM) to expose it as file
named "fram".
Added documentation of sysfs file.

Signed-off-by: Jiri Prchal <jiri.prchal@xxxxxxxxxxx>
---
v2: no change here
v3: resend and added more recipients
v4: resend
v5: no change here
v6: changed commit subject
v7: no change here
v8: changed subject
v9: no change here
v10: moved documentation to here
---
Documentation/ABI/testing/sysfs-class-spi-eeprom | 8 ++++++++
drivers/nvmem/core.c | 4 ++++
include/linux/nvmem-provider.h | 1 +
3 files changed, 13 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-class-spi-eeprom

diff --git a/Documentation/ABI/testing/sysfs-class-spi-eeprom b/Documentation/ABI/testing/sysfs-class-spi-eeprom
new file mode 100644
index 000000000000..7447e242d415
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-spi-eeprom
@@ -0,0 +1,8 @@
+What: /sys/class/spi_master/spi<bus>/spi<bus>.<dev>/fram
+Date: June 2021
+KernelVersion: 5.14
+Contact: Jiri Prchal <jiri.prchal@xxxxxxxxxxx>
+Description:
+ Contains the FRAM binary data. Same as EEPROM, just another file
+ name to indicate that it employs ferroelectric process.
+ It performs write operations at bus speed - no write delays.
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 177f5bf27c6d..01ef9a934b0a 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -180,6 +180,7 @@ static const char * const nvmem_type_str[] = {
[NVMEM_TYPE_EEPROM] = "EEPROM",
[NVMEM_TYPE_OTP] = "OTP",
[NVMEM_TYPE_BATTERY_BACKED] = "Battery backed",
+ [NVMEM_TYPE_FRAM] = "FRAM",
};

#ifdef CONFIG_DEBUG_LOCK_ALLOC
@@ -359,6 +360,9 @@ static int nvmem_sysfs_setup_compat(struct nvmem_device *nvmem,
if (!config->base_dev)
return -EINVAL;

+ if (config->type == NVMEM_TYPE_FRAM)
+ bin_attr_nvmem_eeprom_compat.attr.name = "fram";
+
nvmem->eeprom = bin_attr_nvmem_eeprom_compat;
nvmem->eeprom.attr.mode = nvmem_bin_attr_get_umode(nvmem);
nvmem->eeprom.size = nvmem->size;
diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h
index e162b757b6d5..890003565761 100644
--- a/include/linux/nvmem-provider.h
+++ b/include/linux/nvmem-provider.h
@@ -25,6 +25,7 @@ enum nvmem_type {
NVMEM_TYPE_EEPROM,
NVMEM_TYPE_OTP,
NVMEM_TYPE_BATTERY_BACKED,
+ NVMEM_TYPE_FRAM,
};

#define NVMEM_DEVID_NONE (-1)
--
2.25.1