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 19 static 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 29 static 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 if (data->noinc_reg && data->noinc_reg(data, r)) { 45 memcpy(&our_buf[r], val + val_len - 2, 2); 46 data->written[r] = true; 47 } else { 48 memcpy(&our_buf[r], val, val_len); 49 50 for (i = 0; i < val_len / 2; i++) 51 data->written[r + i] = true; 52 } 53 54 return 0; 55 } 56 57 static int regmap_raw_ram_write(void *context, const void *data, size_t count) 58 { 59 return regmap_raw_ram_gather_write(context, data, 2, 60 data + 2, count - 2); 61 } 62 63 static int regmap_raw_ram_read(void *context, 64 const void *reg, size_t reg_len, 65 void *val, size_t val_len) 66 { 67 struct regmap_ram_data *data = context; 68 unsigned int r; 69 u16 *our_buf = (u16 *)data->vals; 70 int i; 71 72 if (reg_len != 2) 73 return -EINVAL; 74 if (val_len % 2) 75 return -EINVAL; 76 77 r = decode_reg(data->reg_endian, reg); 78 if (data->noinc_reg && data->noinc_reg(data, r)) { 79 for (i = 0; i < val_len; i += 2) 80 memcpy(val + i, &our_buf[r], 2); 81 data->read[r] = true; 82 } else { 83 memcpy(val, &our_buf[r], val_len); 84 85 for (i = 0; i < val_len / 2; i++) 86 data->read[r + i] = true; 87 } 88 89 return 0; 90 } 91 92 static void regmap_raw_ram_free_context(void *context) 93 { 94 struct regmap_ram_data *data = context; 95 96 kfree(data->vals); 97 kfree(data->read); 98 kfree(data->written); 99 kfree(data); 100 } 101 102 static const struct regmap_bus regmap_raw_ram = { 103 .fast_io = true, 104 .write = regmap_raw_ram_write, 105 .gather_write = regmap_raw_ram_gather_write, 106 .read = regmap_raw_ram_read, 107 .free_context = regmap_raw_ram_free_context, 108 }; 109 110 struct regmap *__regmap_init_raw_ram(struct device *dev, 111 const struct regmap_config *config, 112 struct regmap_ram_data *data, 113 struct lock_class_key *lock_key, 114 const char *lock_name) 115 { 116 struct regmap *map; 117 118 if (config->reg_bits != 16) 119 return ERR_PTR(-EINVAL); 120 121 if (!config->max_register) { 122 pr_crit("No max_register specified for RAM regmap\n"); 123 return ERR_PTR(-EINVAL); 124 } 125 126 data->read = kcalloc(config->max_register + 1, sizeof(bool), 127 GFP_KERNEL); 128 if (!data->read) 129 return ERR_PTR(-ENOMEM); 130 131 data->written = kcalloc(config->max_register + 1, sizeof(bool), 132 GFP_KERNEL); 133 if (!data->written) 134 return ERR_PTR(-ENOMEM); 135 136 data->reg_endian = config->reg_format_endian; 137 138 map = __regmap_init(dev, ®map_raw_ram, data, config, 139 lock_key, lock_name); 140 141 return map; 142 } 143 EXPORT_SYMBOL_GPL(__regmap_init_raw_ram); 144 145 MODULE_DESCRIPTION("Register map access API - Memory region with raw access"); 146 MODULE_LICENSE("GPL v2"); 147