target/linux/generic/backport-5.15/802-v5.16-0002-nvmem-core-add-nvmem-cell-post-processing-callback.patch

   1 From 5008062f1c3f5af3acf86164aa6fcc77b0c7bdce Mon Sep 17 00:00:00 2001
   2 From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
   3 Date: Wed, 13 Oct 2021 14:19:56 +0100
   4 Subject: [PATCH] nvmem: core: add nvmem cell post processing callback
   5
   6 Some NVMEM providers have certain nvmem cells encoded, which requires
   7 post processing before actually using it.
   8
   9 For example mac-address is stored in either in ascii or delimited or reverse-order.
  10
  11 Having a post-process callback hook to provider drivers would enable them to
  12 do this vendor specific post processing before nvmem consumers see it.
  13
  14 Tested-by: Joakim Zhang <qiangqing.zhang@nxp.com>
  15 Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
  16 Link: https://lore.kernel.org/r/20211013131957.30271-3-srinivas.kandagatla@linaro.org
  17 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  18 ---
  19  drivers/nvmem/core.c           | 9 +++++++++
  20  include/linux/nvmem-provider.h | 5 +++++
  21  2 files changed, 14 insertions(+)
  22
  23 --- a/drivers/nvmem/core.c
  24 +++ b/drivers/nvmem/core.c
  25 @@ -38,6 +38,7 @@ struct nvmem_device {
  26         unsigned int            nkeepout;
  27         nvmem_reg_read_t        reg_read;
  28         nvmem_reg_write_t       reg_write;
  29 +       nvmem_cell_post_process_t cell_post_process;
  30         struct gpio_desc        *wp_gpio;
  31         void *priv;
  32  };
  33 @@ -799,6 +800,7 @@ struct nvmem_device *nvmem_register(cons
  34         nvmem->type = config->type;
  35         nvmem->reg_read = config->reg_read;
  36         nvmem->reg_write = config->reg_write;
  37 +       nvmem->cell_post_process = config->cell_post_process;
  38         nvmem->keepout = config->keepout;
  39         nvmem->nkeepout = config->nkeepout;
  40         if (config->of_node)
  41 @@ -1441,6 +1443,13 @@ static int __nvmem_cell_read(struct nvme
  42         if (cell->bit_offset || cell->nbits)
  43                 nvmem_shift_read_buffer_in_place(cell, buf);
  44
  45 +       if (nvmem->cell_post_process) {
  46 +               rc = nvmem->cell_post_process(nvmem->priv, id,
  47 +                                             cell->offset, buf, cell->bytes);
  48 +               if (rc)
  49 +                       return rc;
  50 +       }
  51 +
  52         if (len)
  53                 *len = cell->bytes;
  54
  55 --- a/include/linux/nvmem-provider.h
  56 +++ b/include/linux/nvmem-provider.h
  57 @@ -19,6 +19,9 @@ typedef int (*nvmem_reg_read_t)(void *pr
  58                                 void *val, size_t bytes);
  59  typedef int (*nvmem_reg_write_t)(void *priv, unsigned int offset,
  60                                  void *val, size_t bytes);
  61 +/* used for vendor specific post processing of cell data */
  62 +typedef int (*nvmem_cell_post_process_t)(void *priv, const char *id, unsigned int offset,
  63 +                                         void *buf, size_t bytes);
  64
  65  enum nvmem_type {
  66         NVMEM_TYPE_UNKNOWN = 0,
  67 @@ -62,6 +65,7 @@ struct nvmem_keepout {
  68   * @no_of_node:        Device should not use the parent's of_node even if it's !NULL.
  69   * @reg_read:  Callback to read data.
  70   * @reg_write: Callback to write data.
  71 + * @cell_post_process: Callback for vendor specific post processing of cell data
  72   * @size:      Device size.
  73   * @word_size: Minimum read/write access granularity.
  74   * @stride:    Minimum read/write access stride.
  75 @@ -92,6 +96,7 @@ struct nvmem_config {
  76         bool                    no_of_node;
  77         nvmem_reg_read_t        reg_read;
  78         nvmem_reg_write_t       reg_write;
  79 +       nvmem_cell_post_process_t cell_post_process;
  80         int     size;
  81         int     word_size;
  82         int     stride;