Commit graph

7 commits

Author SHA1 Message Date
Théo Lebrun
7e606c311f nvmem: rmem: add CRC validation for Mobileye EyeQ5 NVMEM
Mobileye EyeQ5 has a non-volatile memory region which
gets used to store MAC addresses. Its format includes
a prefix 12-byte header and a suffix 4-byte CRC.

Add an optional ->checksum() callback inside match data;
it runs CRC32 onto the content.

Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20241230143035.265518-7-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-30 15:36:00 +01:00
Théo Lebrun
e44f5a619f nvmem: rmem: remove unused struct rmem::size field
The private structure used by the rmem driver contains
a `size` field that is unused. Remove it.

Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20241230143035.265518-6-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-30 15:36:00 +01:00
Théo Lebrun
9c1d9de52b nvmem: rmem: make ->reg_read() straight forward code
memory_read_from_buffer() is a weird choice; it:
 - is made for iteration with ppos a pointer.
 - does futile error checking in our case.
 - does NOT ensure we read exactly N bytes.

Replace it by:
1. A check that (offset + bytes) lands inside the region and,
2. a plain memcpy().

Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20241230143035.265518-5-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-30 15:35:59 +01:00
Joy Chakraborty
28b008751a nvmem: rmem: Fix return value of rmem_read()
reg_read() callback registered with nvmem core expects 0 on success and
a negative value on error but rmem_read() returns the number of bytes
read which is treated as an error at the nvmem core.

This does not break when rmem is accessed using sysfs via
bin_attr_nvmem_read()/write() but causes an error when accessed from
places like nvmem_access_with_keepouts(), etc.

Change to return 0 on success and error in case
memory_read_from_buffer() returns an error or -EIO if bytes read do not
match what was requested.

Fixes: 5a3fa75a4d ("nvmem: Add driver to expose reserved memory as nvmem")
Cc: stable@vger.kernel.org
Signed-off-by: Joy Chakraborty <joychakr@google.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20240628113704.13742-2-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-03 16:37:51 +02:00
Phil Elwell
09dd7b993e nvmem: rmem: Use NVMEM_DEVID_AUTO
It is reasonable to declare multiple nvmem blocks. Unless a unique 'id'
is passed in for each block there may be name clashes.

Avoid this by using the magic token NVMEM_DEVID_AUTO.

Fixes: 5a3fa75a4d ("nvmem: Add driver to expose reserved memory as nvmem")
Signed-off-by: Phil Elwell <phil@raspberrypi.com>
Signed-off-by: Ivan T. Ivanov <iivanov@suse.de>
Reviewed-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Message-ID: <20230611140330.154222-6-srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-15 13:42:18 +02:00
Wei Yongjun
58e92c4a49 nvmem: rmem: Fix return value check in rmem_read()
In case of error, the function memremap() returns NULL pointer
not ERR_PTR(). The IS_ERR() test in the return value check
should be replaced with NULL test.

Fixes: 5a3fa75a4d ("nvmem: Add driver to expose reserved memory as nvmem")
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20221118063840.6357-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-22 18:21:58 +01:00
Nicolas Saenz Julienne
5a3fa75a4d nvmem: Add driver to expose reserved memory as nvmem
Firmware/co-processors might use reserved memory areas in order to pass
data stemming from an nvmem device otherwise non accessible to Linux.
For example an EEPROM memory only physically accessible to firmware, or
data only accessible early at boot time.

In order to expose this data to other drivers and user-space, the driver
models the reserved memory area as an nvmem device.

Tested-by: Tim Gover <tim.gover@raspberrypi.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20210129171430.11328-5-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-04 17:04:18 +01:00