drivers/base/regmap/regmap-ram.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // Register map access API - Memory region
   4 //
   5 // This is intended for testing only
   6 //
   7 // Copyright (c) 2023, Arm Ltd
   8
   9 #include <linux/clk.h>
  10 #include <linux/err.h>
  11 #include <linux/io.h>
  12 #include <linux/module.h>
  13 #include <linux/regmap.h>
  14 #include <linux/slab.h>
  15 #include <linux/swab.h>
  16
  17 #include "internal.h"
  18
  19 static int regmap_ram_write(void *context, unsigned int reg, unsigned int val)
  20 {
  21         struct regmap_ram_data *data = context;
  22
  23         data->vals[reg] = val;
  24         data->written[reg] = true;
  25
  26         return 0;
  27 }
  28
  29 static int regmap_ram_read(void *context, unsigned int reg, unsigned int *val)
  30 {
  31         struct regmap_ram_data *data = context;
  32
  33         *val = data->vals[reg];
  34         data->read[reg] = true;
  35
  36         return 0;
  37 }
  38
  39 static void regmap_ram_free_context(void *context)
  40 {
  41         struct regmap_ram_data *data = context;
  42
  43         kfree(data->vals);
  44         kfree(data->read);
  45         kfree(data->written);
  46         kfree(data);
  47 }
  48
  49 static const struct regmap_bus regmap_ram = {
  50         .fast_io = true,
  51         .reg_write = regmap_ram_write,
  52         .reg_read = regmap_ram_read,
  53         .free_context = regmap_ram_free_context,
  54 };
  55
  56 struct regmap *__regmap_init_ram(struct device *dev,
  57                                  const struct regmap_config *config,
  58                                  struct regmap_ram_data *data,
  59                                  struct lock_class_key *lock_key,
  60                                  const char *lock_name)
  61 {
  62         struct regmap *map;
  63
  64         if (!config->max_register) {
  65                 pr_crit("No max_register specified for RAM regmap\n");
  66                 return ERR_PTR(-EINVAL);
  67         }
  68
  69         data->read = kcalloc(config->max_register + 1, sizeof(bool),
  70                              GFP_KERNEL);
  71         if (!data->read)
  72                 return ERR_PTR(-ENOMEM);
  73
  74         data->written = kcalloc(config->max_register + 1, sizeof(bool),
  75                                 GFP_KERNEL);
  76         if (!data->written)
  77                 return ERR_PTR(-ENOMEM);
  78
  79         map = __regmap_init(dev, &regmap_ram, data, config,
  80                             lock_key, lock_name);
  81
  82         return map;
  83 }
  84 EXPORT_SYMBOL_GPL(__regmap_init_ram);
  85
  86 MODULE_DESCRIPTION("Register map access API - Memory region");
  87 MODULE_LICENSE("GPL v2");