tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2//
3// Register map access API - Memory region with raw access
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
19static unsigned int decode_reg(enum regmap_endian endian, const void *reg)
20{
21 const u16 *r = reg;
22
23 if (endian == REGMAP_ENDIAN_BIG)
24 return be16_to_cpu(*r);
25 else
26 return le16_to_cpu(*r);
27}
28
29static int regmap_raw_ram_gather_write(void *context,
30 const void *reg, size_t reg_len,
31 const void *val, size_t val_len)
32{
33 struct regmap_ram_data *data = context;
34 unsigned int r;
35 u16 *our_buf = (u16 *)data->vals;
36 int i;
37
38 if (reg_len != 2)
39 return -EINVAL;
40 if (val_len % 2)
41 return -EINVAL;
42
43 r = decode_reg(data->reg_endian, reg);
44 memcpy(&our_buf[r], val, val_len);
45
46 for (i = 0; i < val_len / 2; i++)
47 data->written[r + i] = true;
48
49 return 0;
50}
51
52static int regmap_raw_ram_write(void *context, const void *data, size_t count)
53{
54 return regmap_raw_ram_gather_write(context, data, 2,
55 data + 2, count - 2);
56}
57
58static int regmap_raw_ram_read(void *context,
59 const void *reg, size_t reg_len,
60 void *val, size_t val_len)
61{
62 struct regmap_ram_data *data = context;
63 unsigned int r;
64 u16 *our_buf = (u16 *)data->vals;
65 int i;
66
67 if (reg_len != 2)
68 return -EINVAL;
69 if (val_len % 2)
70 return -EINVAL;
71
72 r = decode_reg(data->reg_endian, reg);
73 memcpy(val, &our_buf[r], val_len);
74
75 for (i = 0; i < val_len / 2; i++)
76 data->read[r + i] = true;
77
78 return 0;
79}
80
81static void regmap_raw_ram_free_context(void *context)
82{
83 struct regmap_ram_data *data = context;
84
85 kfree(data->vals);
86 kfree(data->read);
87 kfree(data->written);
88 kfree(data);
89}
90
91static const struct regmap_bus regmap_raw_ram = {
92 .fast_io = true,
93 .write = regmap_raw_ram_write,
94 .gather_write = regmap_raw_ram_gather_write,
95 .read = regmap_raw_ram_read,
96 .free_context = regmap_raw_ram_free_context,
97};
98
99struct regmap *__regmap_init_raw_ram(const struct regmap_config *config,
100 struct regmap_ram_data *data,
101 struct lock_class_key *lock_key,
102 const char *lock_name)
103{
104 struct regmap *map;
105
106 if (config->reg_bits != 16)
107 return ERR_PTR(-EINVAL);
108
109 if (!config->max_register) {
110 pr_crit("No max_register specified for RAM regmap\n");
111 return ERR_PTR(-EINVAL);
112 }
113
114 data->read = kcalloc(sizeof(bool), config->max_register + 1,
115 GFP_KERNEL);
116 if (!data->read)
117 return ERR_PTR(-ENOMEM);
118
119 data->written = kcalloc(sizeof(bool), config->max_register + 1,
120 GFP_KERNEL);
121 if (!data->written)
122 return ERR_PTR(-ENOMEM);
123
124 data->reg_endian = config->reg_format_endian;
125
126 map = __regmap_init(NULL, ®map_raw_ram, data, config,
127 lock_key, lock_name);
128
129 return map;
130}
131EXPORT_SYMBOL_GPL(__regmap_init_raw_ram);
132
133MODULE_LICENSE("GPL v2");