1 /* 2 * Register map access API - SPI support 3 * 4 * Copyright 2011 Wolfson Microelectronics plc 5 * 6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 */ 12 13 #include <linux/regmap.h> 14 #include <linux/spi/spi.h> 15 #include <linux/init.h> 16 #include <linux/module.h> 17 18 static int regmap_spi_write(void *context, const void *data, size_t count) 19 { 20 struct device *dev = context; 21 struct spi_device *spi = to_spi_device(dev); 22 23 return spi_write(spi, data, count); 24 } 25 26 static int regmap_spi_gather_write(void *context, 27 const void *reg, size_t reg_len, 28 const void *val, size_t val_len) 29 { 30 struct device *dev = context; 31 struct spi_device *spi = to_spi_device(dev); 32 struct spi_message m; 33 struct spi_transfer t[2] = { { .tx_buf = reg, .len = reg_len, }, 34 { .tx_buf = val, .len = val_len, }, }; 35 36 spi_message_init(&m); 37 spi_message_add_tail(&t[0], &m); 38 spi_message_add_tail(&t[1], &m); 39 40 return spi_sync(spi, &m); 41 } 42 43 static int regmap_spi_read(void *context, 44 const void *reg, size_t reg_size, 45 void *val, size_t val_size) 46 { 47 struct device *dev = context; 48 struct spi_device *spi = to_spi_device(dev); 49 50 return spi_write_then_read(spi, reg, reg_size, val, val_size); 51 } 52 53 static struct regmap_bus regmap_spi = { 54 .write = regmap_spi_write, 55 .gather_write = regmap_spi_gather_write, 56 .read = regmap_spi_read, 57 .read_flag_mask = 0x80, 58 }; 59 60 /** 61 * regmap_init_spi(): Initialise register map 62 * 63 * @spi: Device that will be interacted with 64 * @config: Configuration for register map 65 * 66 * The return value will be an ERR_PTR() on error or a valid pointer to 67 * a struct regmap. 68 */ 69 struct regmap *regmap_init_spi(struct spi_device *spi, 70 const struct regmap_config *config) 71 { 72 return regmap_init(&spi->dev, ®map_spi, &spi->dev, config); 73 } 74 EXPORT_SYMBOL_GPL(regmap_init_spi); 75 76 /** 77 * devm_regmap_init_spi(): Initialise register map 78 * 79 * @spi: Device that will be interacted with 80 * @config: Configuration for register map 81 * 82 * The return value will be an ERR_PTR() on error or a valid pointer 83 * to a struct regmap. The map will be automatically freed by the 84 * device management code. 85 */ 86 struct regmap *devm_regmap_init_spi(struct spi_device *spi, 87 const struct regmap_config *config) 88 { 89 return devm_regmap_init(&spi->dev, ®map_spi, &spi->dev, config); 90 } 91 EXPORT_SYMBOL_GPL(devm_regmap_init_spi); 92 93 MODULE_LICENSE("GPL"); 94