kernel: backport NVMEM patches queued for the v6.4

[openwrt/openwrt.git] / target / linux / generic / backport-5.10 / 814-v6.4-0005-nvmem-core-add-per-cell-post-processing.patch

diff --git a/target/linux/generic/backport-5.10/814-v6.4-0005-nvmem-core-add-per-cell-post-processing.patch b/target/linux/generic/backport-5.10/814-v6.4-0005-nvmem-core-add-per-cell-post-processing.patch
new file mode 100644 (file)
index 0000000..53628cd
--- /dev/null
+++ b/target/linux/generic/backport-5.10/814-v6.4-0005-nvmem-core-add-per-cell-post-processing.patch
@@ -0,0 +1,86 @@
+From 345ec382cd4b736c36e01f155d08c913b225b736 Mon Sep 17 00:00:00 2001
+From: Michael Walle <michael@walle.cc>
+Date: Tue, 4 Apr 2023 18:21:24 +0100
+Subject: [PATCH] nvmem: core: add per-cell post processing
+
+Instead of relying on the name the consumer is using for the cell, like
+it is done for the nvmem .cell_post_process configuration parameter,
+provide a per-cell post processing hook. This can then be populated by
+the NVMEM provider (or the NVMEM layout) when adding the cell.
+
+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/20230404172148.82422-17-srinivas.kandagatla@linaro.org
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/nvmem/core.c           | 17 +++++++++++++++++
+ include/linux/nvmem-provider.h |  3 +++
+ 2 files changed, 20 insertions(+)
+
+--- a/drivers/nvmem/core.c
++++ b/drivers/nvmem/core.c
+@@ -54,6 +54,7 @@ struct nvmem_cell_entry {
+       int                     bytes;
+       int                     bit_offset;
+       int                     nbits;
++      nvmem_cell_post_process_t read_post_process;
+       struct device_node      *np;
+       struct nvmem_device     *nvmem;
+       struct list_head        node;
+@@ -470,6 +471,7 @@ static int nvmem_cell_info_to_nvmem_cell
+       cell->offset = info->offset;
+       cell->bytes = info->bytes;
+       cell->name = info->name;
++      cell->read_post_process = info->read_post_process;
+ 
+       cell->bit_offset = info->bit_offset;
+       cell->nbits = info->nbits;
+@@ -1563,6 +1565,13 @@ static int __nvmem_cell_read(struct nvme
+       if (cell->bit_offset || cell->nbits)
+               nvmem_shift_read_buffer_in_place(cell, buf);
+ 
++      if (cell->read_post_process) {
++              rc = cell->read_post_process(nvmem->priv, id, index,
++                                           cell->offset, buf, cell->bytes);
++              if (rc)
++                      return rc;
++      }
++
+       if (nvmem->cell_post_process) {
+               rc = nvmem->cell_post_process(nvmem->priv, id, index,
+                                             cell->offset, buf, cell->bytes);
+@@ -1671,6 +1680,14 @@ static int __nvmem_cell_entry_write(stru
+           (cell->bit_offset == 0 && len != cell->bytes))
+               return -EINVAL;
+ 
++      /*
++       * Any cells which have a read_post_process hook are read-only because
++       * we cannot reverse the operation and it might affect other cells,
++       * too.
++       */
++      if (cell->read_post_process)
++              return -EINVAL;
++
+       if (cell->bit_offset || cell->nbits) {
+               buf = nvmem_cell_prepare_write_buffer(cell, buf, len);
+               if (IS_ERR(buf))
+--- a/include/linux/nvmem-provider.h
++++ b/include/linux/nvmem-provider.h
+@@ -54,6 +54,8 @@ struct nvmem_keepout {
+  * @bit_offset:       Bit offset if cell is smaller than a byte.
+  * @nbits:    Number of bits.
+  * @np:               Optional device_node pointer.
++ * @read_post_process:        Callback for optional post processing of cell data
++ *                    on reads.
+  */
+ struct nvmem_cell_info {
+       const char              *name;
+@@ -62,6 +64,7 @@ struct nvmem_cell_info {
+       unsigned int            bit_offset;
+       unsigned int            nbits;
+       struct device_node      *np;
++      nvmem_cell_post_process_t read_post_process;
+ };
+ 
+ /**