/* * Driver for the Analog Devices digital potentiometers (SPI bus) * * Copyright (C) 2010 Michael Hennerich, Analog Devices Inc. * * Licensed under the GPL-2 or later. */ #include <linux/spi/spi.h> #include <linux/module.h> #include "ad525x_dpot.h" static const struct ad_dpot_id ad_dpot_spi_devlist[] = { {.name = "ad5160", .devid = AD5160_ID}, {.name = "ad5161", .devid = AD5161_ID}, {.name = "ad5162", .devid = AD5162_ID}, {.name = "ad5165", .devid = AD5165_ID}, {.name = "ad5200", .devid = AD5200_ID}, {.name = "ad5201", .devid = AD5201_ID}, {.name = "ad5203", .devid = AD5203_ID}, {.name = "ad5204", .devid = AD5204_ID}, {.name = "ad5206", .devid = AD5206_ID}, {.name = "ad5207", .devid = AD5207_ID}, {.name = "ad5231", .devid = AD5231_ID}, {.name = "ad5232", .devid = AD5232_ID}, {.name = "ad5233", .devid = AD5233_ID}, {.name = "ad5235", .devid = AD5235_ID}, {.name = "ad5260", .devid = AD5260_ID}, {.name = "ad5262", .devid = AD5262_ID}, {.name = "ad5263", .devid = AD5263_ID}, {.name = "ad5290", .devid = AD5290_ID}, {.name = "ad5291", .devid = AD5291_ID}, {.name = "ad5292", .devid = AD5292_ID}, {.name = "ad5293", .devid = AD5293_ID}, {.name = "ad7376", .devid = AD7376_ID}, {.name = "ad8400", .devid = AD8400_ID}, {.name = "ad8402", .devid = AD8402_ID}, {.name = "ad8403", .devid = AD8403_ID}, {.name = "adn2850", .devid = ADN2850_ID}, {} }; /* ------------------------------------------------------------------------- */ /* SPI bus functions */ static int write8(void *client, u8 val) { u8 data = val; return spi_write(client, &data, 1); } static int write16(void *client, u8 reg, u8 val) { u8 data[2] = {reg, val}; return spi_write(client, data, 1); } static int write24(void *client, u8 reg, u16 val) { u8 data[3] = {reg, val >> 8, val}; return spi_write(client, data, 1); } static int read8(void *client) { int ret; u8 data; ret = spi_read(client, &data, 1); if (ret < 0) return ret; return data; } static int read16(void *client, u8 reg) { int ret; u8 buf_rx[2]; write16(client, reg, 0); ret = spi_read(client, buf_rx, 2); if (ret < 0) return ret; return (buf_rx[0] << 8) | buf_rx[1]; } static int read24(void *client, u8 reg) { int ret; u8 buf_rx[3]; write24(client, reg, 0); ret = spi_read(client, buf_rx, 3); if (ret < 0) return ret; return (buf_rx[1] << 8) | buf_rx[2]; } static const struct ad_dpot_bus_ops bops = { .read_d8 = read8, .read_r8d8 = read16, .read_r8d16 = read24, .write_d8 = write8, .write_r8d8 = write16, .write_r8d16 = write24, }; static const struct ad_dpot_id *dpot_match_id(const struct ad_dpot_id *id, char *name) { while (id->name && id->name[0]) { if (strcmp(name, id->name) == 0) return id; id++; } return NULL; } static int __devinit ad_dpot_spi_probe(struct spi_device *spi) { char *name = spi->dev.platform_data; const struct ad_dpot_id *dpot_id; struct ad_dpot_bus_data bdata = { .client = spi, .bops = &bops, }; dpot_id = dpot_match_id(ad_dpot_spi_devlist, name); if (dpot_id == NULL) { dev_err(&spi->dev, "%s not in supported device list", name); return -ENODEV; } return ad_dpot_probe(&spi->dev, &bdata, dpot_id); } static int __devexit ad_dpot_spi_remove(struct spi_device *spi) { return ad_dpot_remove(&spi->dev); } static struct spi_driver ad_dpot_spi_driver = { .driver = { .name = "ad_dpot", .bus = &spi_bus_type, .owner = THIS_MODULE, }, .probe = ad_dpot_spi_probe, .remove = __devexit_p(ad_dpot_spi_remove), }; static int __init ad_dpot_spi_init(void) { return spi_register_driver(&ad_dpot_spi_driver); } module_init(ad_dpot_spi_init); static void __exit ad_dpot_spi_exit(void) { spi_unregister_driver(&ad_dpot_spi_driver); } module_exit(ad_dpot_spi_exit); MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); MODULE_DESCRIPTION("digital potentiometer SPI bus driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("spi:ad_dpot");