diff options
Diffstat (limited to 'drivers/misc/ad525x_dpot-spi.c')
| -rw-r--r-- | drivers/misc/ad525x_dpot-spi.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/drivers/misc/ad525x_dpot-spi.c b/drivers/misc/ad525x_dpot-spi.c new file mode 100644 index 0000000..b8c6df9 --- /dev/null +++ b/drivers/misc/ad525x_dpot-spi.c @@ -0,0 +1,172 @@ +/* + * 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"); |