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 17 static int regmap_spi_write(struct device *dev, const void *data, size_t count) 18 { 19 struct spi_device *spi = to_spi_device(dev); 20 21 return spi_write(spi, data, count); 22 } 23 24 static int regmap_spi_gather_write(struct device *dev, 25 const void *reg, size_t reg_len, 26 const void *val, size_t val_len) 27 { 28 struct spi_device *spi = to_spi_device(dev); 29 struct spi_message m; 30 struct spi_transfer t[2] = { { .tx_buf = reg, .len = reg_len, }, 31 { .tx_buf = val, .len = val_len, }, }; 32 33 spi_message_init(&m); 34 spi_message_add_tail(&t[0], &m); 35 spi_message_add_tail(&t[1], &m); 36 37 return spi_sync(spi, &m); 38 } 39 40 static int regmap_spi_read(struct device *dev, 41 const void *reg, size_t reg_size, 42 void *val, size_t val_size) 43 { 44 struct spi_device *spi = to_spi_device(dev); 45 46 return spi_write_then_read(spi, reg, reg_size, val, val_size); 47 } 48 49 static struct regmap_bus regmap_spi = { 50 .type = &spi_bus_type, 51 .write = regmap_spi_write, 52 .gather_write = regmap_spi_gather_write, 53 .read = regmap_spi_read, 54 .owner = THIS_MODULE, 55 .read_flag_mask = 0x80, 56 }; 57 58 /** 59 * regmap_init_spi(): Initialise register map 60 * 61 * @spi: Device that will be interacted with 62 * @config: Configuration for register map 63 * 64 * The return value will be an ERR_PTR() on error or a valid pointer to 65 * a struct regmap. 66 */ 67 struct regmap *regmap_init_spi(struct spi_device *spi, 68 const struct regmap_config *config) 69 { 70 return regmap_init(&spi->dev, ®map_spi, config); 71 } 72 EXPORT_SYMBOL_GPL(regmap_init_spi); 73