xref: /openbmc/linux/drivers/base/regmap/regmap-ram.c (revision 9b68f30b)
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(const struct regmap_config *config,
57 				 struct regmap_ram_data *data,
58 				 struct lock_class_key *lock_key,
59 				 const char *lock_name)
60 {
61 	struct regmap *map;
62 
63 	if (!config->max_register) {
64 		pr_crit("No max_register specified for RAM regmap\n");
65 		return ERR_PTR(-EINVAL);
66 	}
67 
68 	data->read = kcalloc(sizeof(bool), config->max_register + 1,
69 			     GFP_KERNEL);
70 	if (!data->read)
71 		return ERR_PTR(-ENOMEM);
72 
73 	data->written = kcalloc(sizeof(bool), config->max_register + 1,
74 				GFP_KERNEL);
75 	if (!data->written)
76 		return ERR_PTR(-ENOMEM);
77 
78 	map = __regmap_init(NULL, &regmap_ram, data, config,
79 			    lock_key, lock_name);
80 
81 	return map;
82 }
83 EXPORT_SYMBOL_GPL(__regmap_init_ram);
84 
85 MODULE_LICENSE("GPL v2");
86