[V2,1/2] nvmem: core: refactor .cell_post_process() CB arguments
Commit Message
From: Rafał Miłecki <rafal@milecki.pl>
Pass whole NVMEM cell struct and length pointer as arguments to callback
functions.
This allows:
1. Cells content to be modified based on more info
Some cells (identified by their names) contain specific data that
needs further processing. This can be e.g. MAC address stored in an
ASCII format. NVMEM consumers expect MAC to be read in a binary form.
More complex cells may be additionally described in DT. This change
allows also accessing relevant DT nodes and reading extra info.
2. Adjusting data length
If cell processing results in reformatting it, it's required to
adjust length. This again applies e.g. to the MAC format change from
ASCII to the byte-based.
Later on we may consider more cleanups & features like:
1. Dropping "const char *id" and just using NVMEM cell name
2. Adding extra argument for cells providing multiple values
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---
This solution conflicts with 1 part of Michael's work:
[PATCH v2 00/20] nvmem: core: introduce NVMEM layouts
https://lore.kernel.org/linux-arm-kernel/20220901221857.2600340-1-michael@walle.cc/
Instead of:
1. Adding NVMEM cell-level post_process callback
2. Adding callback (.fixup_cell_info()) for setting callbacks
3. Dropping NVMEM device-level post_process callback
I decided to refactor existing callback.
Michael's work on adding #nvmem-cell-cells should be possible to easily
rebase on top of those changes.
This doen't add support for 1 cell providing multiple values. That needs
to be added later once we sort out #nvmem-cell-cells bindings. This
fixes the basic case with reformatting cells data.
---
drivers/nvmem/core.c | 19 +++----------------
drivers/nvmem/imx-ocotp.c | 8 ++++----
include/linux/nvmem-provider.h | 17 ++++++++++++++---
3 files changed, 21 insertions(+), 23 deletions(-)
Comments
Am 2022-11-28 07:59, schrieb Rafał Miłecki:
> From: Rafał Miłecki <rafal@milecki.pl>
>
> Pass whole NVMEM cell struct and length pointer as arguments to
> callback
> functions.
>
> This allows:
>
> 1. Cells content to be modified based on more info
> Some cells (identified by their names) contain specific data that
> needs further processing. This can be e.g. MAC address stored in an
> ASCII format. NVMEM consumers expect MAC to be read in a binary
> form.
> More complex cells may be additionally described in DT. This change
> allows also accessing relevant DT nodes and reading extra info.
>
> 2. Adjusting data length
> If cell processing results in reformatting it, it's required to
> adjust length. This again applies e.g. to the MAC format change from
> ASCII to the byte-based.
>
> Later on we may consider more cleanups & features like:
> 1. Dropping "const char *id" and just using NVMEM cell name
> 2. Adding extra argument for cells providing multiple values
>
> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> ---
> This solution conflicts with 1 part of Michael's work:
> [PATCH v2 00/20] nvmem: core: introduce NVMEM layouts
> https://lore.kernel.org/linux-arm-kernel/20220901221857.2600340-1-michael@walle.cc/
>
> Instead of:
> 1. Adding NVMEM cell-level post_process callback
> 2. Adding callback (.fixup_cell_info()) for setting callbacks
> 3. Dropping NVMEM device-level post_process callback
> I decided to refactor existing callback.
>
> Michael's work on adding #nvmem-cell-cells should be possible to easily
> rebase on top of those changes.
As yours should be easily added on top of my series. I've showed that
providing a global post process hook is bad because that way you need
to have *all* cells of your device read-only.
-michael
Hi Rafal,
michael@walle.cc wrote on Mon, 28 Nov 2022 08:35:24 +0100:
> Am 2022-11-28 07:59, schrieb Rafał Miłecki:
> > From: Rafał Miłecki <rafal@milecki.pl>
> >
> > Pass whole NVMEM cell struct and length pointer as arguments to > callback
> > functions.
> >
> > This allows:
> >
> > 1. Cells content to be modified based on more info
> > Some cells (identified by their names) contain specific data that
> > needs further processing. This can be e.g. MAC address stored in an
> > ASCII format. NVMEM consumers expect MAC to be read in a binary > form.
> > More complex cells may be additionally described in DT. This change
> > allows also accessing relevant DT nodes and reading extra info.
> >
> > 2. Adjusting data length
> > If cell processing results in reformatting it, it's required to
> > adjust length. This again applies e.g. to the MAC format change from
> > ASCII to the byte-based.
Michael's series brings read_post_process, isn't what you need here?
> >
> > Later on we may consider more cleanups & features like:
> > 1. Dropping "const char *id" and just using NVMEM cell name
> > 2. Adding extra argument for cells providing multiple values
> >
> > Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> > ---
> > This solution conflicts with 1 part of Michael's work:
> > [PATCH v2 00/20] nvmem: core: introduce NVMEM layouts
> > https://lore.kernel.org/linux-arm-kernel/20220901221857.2600340-1-michael@walle.cc/
> >
> > Instead of:
> > 1. Adding NVMEM cell-level post_process callback
> > 2. Adding callback (.fixup_cell_info()) for setting callbacks
> > 3. Dropping NVMEM device-level post_process callback
> > I decided to refactor existing callback.
> >
> > Michael's work on adding #nvmem-cell-cells should be possible to easily
> > rebase on top of those changes.
Yeah, I guess since Michael's series has been out for 2 years and we
finally agreed on the bindings plus some implementation points, I would
expect it to be merged very soon (I don't know if Srinivas still plans
to take it for this release or for the next?) unless someone speaks up
against it.
> As yours should be easily added on top of my series. I've showed that
> providing a global post process hook is bad because that way you need
> to have *all* cells of your device read-only.
>
> -michael
Thanks,
Miquèl
@@ -46,16 +46,6 @@ struct nvmem_device {
#define to_nvmem_device(d) container_of(d, struct nvmem_device, dev)
#define FLAG_COMPAT BIT(0)
-struct nvmem_cell_entry {
- const char *name;
- int offset;
- int bytes;
- int bit_offset;
- int nbits;
- struct device_node *np;
- struct nvmem_device *nvmem;
- struct list_head node;
-};
struct nvmem_cell {
struct nvmem_cell_entry *entry;
@@ -1416,24 +1406,21 @@ static int __nvmem_cell_read(struct nvmem_device *nvmem,
int rc;
rc = nvmem_reg_read(nvmem, cell->offset, buf, cell->bytes);
-
if (rc)
return rc;
+ if (len)
+ *len = cell->bytes;
/* shift bits in-place */
if (cell->bit_offset || cell->nbits)
nvmem_shift_read_buffer_in_place(cell, buf);
if (nvmem->cell_post_process) {
- rc = nvmem->cell_post_process(nvmem->priv, id,
- cell->offset, buf, cell->bytes);
+ rc = nvmem->cell_post_process(nvmem->priv, cell, id, buf, len);
if (rc)
return rc;
}
- if (len)
- *len = cell->bytes;
-
return 0;
}
@@ -222,8 +222,8 @@ static int imx_ocotp_read(void *context, unsigned int offset,
return ret;
}
-static int imx_ocotp_cell_pp(void *context, const char *id, unsigned int offset,
- void *data, size_t bytes)
+static int imx_ocotp_cell_pp(void *context, struct nvmem_cell_entry *cell,
+ const char *id, void *data, size_t *len)
{
struct ocotp_priv *priv = context;
@@ -233,8 +233,8 @@ static int imx_ocotp_cell_pp(void *context, const char *id, unsigned int offset,
u8 *buf = data;
int i;
- for (i = 0; i < bytes/2; i++)
- swap(buf[i], buf[bytes - i - 1]);
+ for (i = 0; i < cell->bytes / 2; i++)
+ swap(buf[i], buf[cell->bytes - i - 1]);
}
}
@@ -14,14 +14,25 @@
#include <linux/gpio/consumer.h>
struct nvmem_device;
-struct nvmem_cell_info;
+
+struct nvmem_cell_entry {
+ const char *name;
+ int offset;
+ int bytes;
+ int bit_offset;
+ int nbits;
+ struct device_node *np;
+ struct nvmem_device *nvmem;
+ struct list_head node;
+};
+
typedef int (*nvmem_reg_read_t)(void *priv, unsigned int offset,
void *val, size_t bytes);
typedef int (*nvmem_reg_write_t)(void *priv, unsigned int offset,
void *val, size_t bytes);
/* used for vendor specific post processing of cell data */
-typedef int (*nvmem_cell_post_process_t)(void *priv, const char *id, unsigned int offset,
- void *buf, size_t bytes);
+typedef int (*nvmem_cell_post_process_t)(void *priv, struct nvmem_cell_entry *cell, const char *id,
+ void *buf, size_t *len);
enum nvmem_type {
NVMEM_TYPE_UNKNOWN = 0,