1*65dd2f67SMark Brown // SPDX-License-Identifier: GPL-2.0
2*65dd2f67SMark Brown //
3*65dd2f67SMark Brown // Register map access API - Memory region with raw access
4*65dd2f67SMark Brown //
5*65dd2f67SMark Brown // This is intended for testing only
6*65dd2f67SMark Brown //
7*65dd2f67SMark Brown // Copyright (c) 2023, Arm Ltd
8*65dd2f67SMark Brown
9*65dd2f67SMark Brown #include <linux/clk.h>
10*65dd2f67SMark Brown #include <linux/err.h>
11*65dd2f67SMark Brown #include <linux/io.h>
12*65dd2f67SMark Brown #include <linux/module.h>
13*65dd2f67SMark Brown #include <linux/regmap.h>
14*65dd2f67SMark Brown #include <linux/slab.h>
15*65dd2f67SMark Brown #include <linux/swab.h>
16*65dd2f67SMark Brown
17*65dd2f67SMark Brown #include "internal.h"
18*65dd2f67SMark Brown
decode_reg(enum regmap_endian endian,const void * reg)19*65dd2f67SMark Brown static unsigned int decode_reg(enum regmap_endian endian, const void *reg)
20*65dd2f67SMark Brown {
21*65dd2f67SMark Brown const u16 *r = reg;
22*65dd2f67SMark Brown
23*65dd2f67SMark Brown if (endian == REGMAP_ENDIAN_BIG)
24*65dd2f67SMark Brown return be16_to_cpu(*r);
25*65dd2f67SMark Brown else
26*65dd2f67SMark Brown return le16_to_cpu(*r);
27*65dd2f67SMark Brown }
28*65dd2f67SMark Brown
regmap_raw_ram_gather_write(void * context,const void * reg,size_t reg_len,const void * val,size_t val_len)29*65dd2f67SMark Brown static int regmap_raw_ram_gather_write(void *context,
30*65dd2f67SMark Brown const void *reg, size_t reg_len,
31*65dd2f67SMark Brown const void *val, size_t val_len)
32*65dd2f67SMark Brown {
33*65dd2f67SMark Brown struct regmap_ram_data *data = context;
34*65dd2f67SMark Brown unsigned int r;
35*65dd2f67SMark Brown u16 *our_buf = (u16 *)data->vals;
36*65dd2f67SMark Brown int i;
37*65dd2f67SMark Brown
38*65dd2f67SMark Brown if (reg_len != 2)
39*65dd2f67SMark Brown return -EINVAL;
40*65dd2f67SMark Brown if (val_len % 2)
41*65dd2f67SMark Brown return -EINVAL;
42*65dd2f67SMark Brown
43*65dd2f67SMark Brown r = decode_reg(data->reg_endian, reg);
44*65dd2f67SMark Brown memcpy(&our_buf[r], val, val_len);
45*65dd2f67SMark Brown
46*65dd2f67SMark Brown for (i = 0; i < val_len / 2; i++)
47*65dd2f67SMark Brown data->written[r + i] = true;
48*65dd2f67SMark Brown
49*65dd2f67SMark Brown return 0;
50*65dd2f67SMark Brown }
51*65dd2f67SMark Brown
regmap_raw_ram_write(void * context,const void * data,size_t count)52*65dd2f67SMark Brown static int regmap_raw_ram_write(void *context, const void *data, size_t count)
53*65dd2f67SMark Brown {
54*65dd2f67SMark Brown return regmap_raw_ram_gather_write(context, data, 2,
55*65dd2f67SMark Brown data + 2, count - 2);
56*65dd2f67SMark Brown }
57*65dd2f67SMark Brown
regmap_raw_ram_read(void * context,const void * reg,size_t reg_len,void * val,size_t val_len)58*65dd2f67SMark Brown static int regmap_raw_ram_read(void *context,
59*65dd2f67SMark Brown const void *reg, size_t reg_len,
60*65dd2f67SMark Brown void *val, size_t val_len)
61*65dd2f67SMark Brown {
62*65dd2f67SMark Brown struct regmap_ram_data *data = context;
63*65dd2f67SMark Brown unsigned int r;
64*65dd2f67SMark Brown u16 *our_buf = (u16 *)data->vals;
65*65dd2f67SMark Brown int i;
66*65dd2f67SMark Brown
67*65dd2f67SMark Brown if (reg_len != 2)
68*65dd2f67SMark Brown return -EINVAL;
69*65dd2f67SMark Brown if (val_len % 2)
70*65dd2f67SMark Brown return -EINVAL;
71*65dd2f67SMark Brown
72*65dd2f67SMark Brown r = decode_reg(data->reg_endian, reg);
73*65dd2f67SMark Brown memcpy(val, &our_buf[r], val_len);
74*65dd2f67SMark Brown
75*65dd2f67SMark Brown for (i = 0; i < val_len / 2; i++)
76*65dd2f67SMark Brown data->read[r + i] = true;
77*65dd2f67SMark Brown
78*65dd2f67SMark Brown return 0;
79*65dd2f67SMark Brown }
80*65dd2f67SMark Brown
regmap_raw_ram_free_context(void * context)81*65dd2f67SMark Brown static void regmap_raw_ram_free_context(void *context)
82*65dd2f67SMark Brown {
83*65dd2f67SMark Brown struct regmap_ram_data *data = context;
84*65dd2f67SMark Brown
85*65dd2f67SMark Brown kfree(data->vals);
86*65dd2f67SMark Brown kfree(data->read);
87*65dd2f67SMark Brown kfree(data->written);
88*65dd2f67SMark Brown kfree(data);
89*65dd2f67SMark Brown }
90*65dd2f67SMark Brown
91*65dd2f67SMark Brown static const struct regmap_bus regmap_raw_ram = {
92*65dd2f67SMark Brown .fast_io = true,
93*65dd2f67SMark Brown .write = regmap_raw_ram_write,
94*65dd2f67SMark Brown .gather_write = regmap_raw_ram_gather_write,
95*65dd2f67SMark Brown .read = regmap_raw_ram_read,
96*65dd2f67SMark Brown .free_context = regmap_raw_ram_free_context,
97*65dd2f67SMark Brown };
98*65dd2f67SMark Brown
__regmap_init_raw_ram(const struct regmap_config * config,struct regmap_ram_data * data,struct lock_class_key * lock_key,const char * lock_name)99*65dd2f67SMark Brown struct regmap *__regmap_init_raw_ram(const struct regmap_config *config,
100*65dd2f67SMark Brown struct regmap_ram_data *data,
101*65dd2f67SMark Brown struct lock_class_key *lock_key,
102*65dd2f67SMark Brown const char *lock_name)
103*65dd2f67SMark Brown {
104*65dd2f67SMark Brown struct regmap *map;
105*65dd2f67SMark Brown
106*65dd2f67SMark Brown if (config->reg_bits != 16)
107*65dd2f67SMark Brown return ERR_PTR(-EINVAL);
108*65dd2f67SMark Brown
109*65dd2f67SMark Brown if (!config->max_register) {
110*65dd2f67SMark Brown pr_crit("No max_register specified for RAM regmap\n");
111*65dd2f67SMark Brown return ERR_PTR(-EINVAL);
112*65dd2f67SMark Brown }
113*65dd2f67SMark Brown
114*65dd2f67SMark Brown data->read = kcalloc(sizeof(bool), config->max_register + 1,
115*65dd2f67SMark Brown GFP_KERNEL);
116*65dd2f67SMark Brown if (!data->read)
117*65dd2f67SMark Brown return ERR_PTR(-ENOMEM);
118*65dd2f67SMark Brown
119*65dd2f67SMark Brown data->written = kcalloc(sizeof(bool), config->max_register + 1,
120*65dd2f67SMark Brown GFP_KERNEL);
121*65dd2f67SMark Brown if (!data->written)
122*65dd2f67SMark Brown return ERR_PTR(-ENOMEM);
123*65dd2f67SMark Brown
124*65dd2f67SMark Brown data->reg_endian = config->reg_format_endian;
125*65dd2f67SMark Brown
126*65dd2f67SMark Brown map = __regmap_init(NULL, ®map_raw_ram, data, config,
127*65dd2f67SMark Brown lock_key, lock_name);
128*65dd2f67SMark Brown
129*65dd2f67SMark Brown return map;
130*65dd2f67SMark Brown }
131*65dd2f67SMark Brown EXPORT_SYMBOL_GPL(__regmap_init_raw_ram);
132*65dd2f67SMark Brown
133*65dd2f67SMark Brown MODULE_LICENSE("GPL v2");
134