xref: /linux/drivers/base/regmap/regmap-ram.c (revision da5b2ad1c2f18834cb1ce429e2e5a5cf5cbdf21b)
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");
88