1 // SPDX-License-Identifier: GPL-2.0 2 // 3 // Register map access API - SPI support 4 // 5 // Copyright 2011 Wolfson Microelectronics plc 6 // 7 // Author: Mark Brown <broonie@opensource.wolfsonmicro.com> 8 9 #include <linux/regmap.h> 10 #include <linux/spi/spi.h> 11 #include <linux/module.h> 12 13 #include "internal.h" 14 15 struct regmap_async_spi { 16 struct regmap_async core; 17 struct spi_message m; 18 struct spi_transfer t[2]; 19 }; 20 21 static void regmap_spi_complete(void *data) 22 { 23 struct regmap_async_spi *async = data; 24 25 regmap_async_complete_cb(&async->core, async->m.status); 26 } 27 28 static int regmap_spi_write(void *context, const void *data, size_t count) 29 { 30 struct device *dev = context; 31 struct spi_device *spi = to_spi_device(dev); 32 33 return spi_write(spi, data, count); 34 } 35 36 static int regmap_spi_gather_write(void *context, 37 const void *reg, size_t reg_len, 38 const void *val, size_t val_len) 39 { 40 struct device *dev = context; 41 struct spi_device *spi = to_spi_device(dev); 42 struct spi_message m; 43 struct spi_transfer t[2] = { { .tx_buf = reg, .len = reg_len, }, 44 { .tx_buf = val, .len = val_len, }, }; 45 46 spi_message_init(&m); 47 spi_message_add_tail(&t[0], &m); 48 spi_message_add_tail(&t[1], &m); 49 50 return spi_sync(spi, &m); 51 } 52 53 static int regmap_spi_async_write(void *context, 54 const void *reg, size_t reg_len, 55 const void *val, size_t val_len, 56 struct regmap_async *a) 57 { 58 struct regmap_async_spi *async = container_of(a, 59 struct regmap_async_spi, 60 core); 61 struct device *dev = context; 62 struct spi_device *spi = to_spi_device(dev); 63 64 async->t[0].tx_buf = reg; 65 async->t[0].len = reg_len; 66 async->t[1].tx_buf = val; 67 async->t[1].len = val_len; 68 69 spi_message_init(&async->m); 70 spi_message_add_tail(&async->t[0], &async->m); 71 if (val) 72 spi_message_add_tail(&async->t[1], &async->m); 73 74 async->m.complete = regmap_spi_complete; 75 async->m.context = async; 76 77 return spi_async(spi, &async->m); 78 } 79 80 static struct regmap_async *regmap_spi_async_alloc(void) 81 { 82 struct regmap_async_spi *async_spi; 83 84 async_spi = kzalloc(sizeof(*async_spi), GFP_KERNEL); 85 if (!async_spi) 86 return NULL; 87 88 return &async_spi->core; 89 } 90 91 static int regmap_spi_read(void *context, 92 const void *reg, size_t reg_size, 93 void *val, size_t val_size) 94 { 95 struct device *dev = context; 96 struct spi_device *spi = to_spi_device(dev); 97 98 return spi_write_then_read(spi, reg, reg_size, val, val_size); 99 } 100 101 static const struct regmap_bus regmap_spi = { 102 .write = regmap_spi_write, 103 .gather_write = regmap_spi_gather_write, 104 .async_write = regmap_spi_async_write, 105 .async_alloc = regmap_spi_async_alloc, 106 .read = regmap_spi_read, 107 .read_flag_mask = 0x80, 108 .reg_format_endian_default = REGMAP_ENDIAN_BIG, 109 .val_format_endian_default = REGMAP_ENDIAN_BIG, 110 }; 111 112 static const struct regmap_bus *regmap_get_spi_bus(struct spi_device *spi, 113 const struct regmap_config *config) 114 { 115 size_t max_size = spi_max_transfer_size(spi); 116 size_t max_msg_size, reg_reserve_size; 117 struct regmap_bus *bus; 118 119 if (max_size != SIZE_MAX) { 120 bus = kmemdup(®map_spi, sizeof(*bus), GFP_KERNEL); 121 if (!bus) 122 return ERR_PTR(-ENOMEM); 123 124 max_msg_size = spi_max_message_size(spi); 125 reg_reserve_size = config->reg_bits / BITS_PER_BYTE 126 + config->pad_bits / BITS_PER_BYTE; 127 if (max_size + reg_reserve_size > max_msg_size) 128 max_size -= reg_reserve_size; 129 130 bus->free_on_exit = true; 131 bus->max_raw_read = max_size; 132 bus->max_raw_write = max_size; 133 134 return bus; 135 } 136 137 return ®map_spi; 138 } 139 140 struct regmap *__regmap_init_spi(struct spi_device *spi, 141 const struct regmap_config *config, 142 struct lock_class_key *lock_key, 143 const char *lock_name) 144 { 145 const struct regmap_bus *bus = regmap_get_spi_bus(spi, config); 146 147 if (IS_ERR(bus)) 148 return ERR_CAST(bus); 149 150 return __regmap_init(&spi->dev, bus, &spi->dev, config, lock_key, lock_name); 151 } 152 EXPORT_SYMBOL_GPL(__regmap_init_spi); 153 154 struct regmap *__devm_regmap_init_spi(struct spi_device *spi, 155 const struct regmap_config *config, 156 struct lock_class_key *lock_key, 157 const char *lock_name) 158 { 159 const struct regmap_bus *bus = regmap_get_spi_bus(spi, config); 160 161 if (IS_ERR(bus)) 162 return ERR_CAST(bus); 163 164 return __devm_regmap_init(&spi->dev, bus, &spi->dev, config, lock_key, lock_name); 165 } 166 EXPORT_SYMBOL_GPL(__devm_regmap_init_spi); 167 168 MODULE_DESCRIPTION("regmap SPI Module"); 169 MODULE_LICENSE("GPL"); 170