diff options
Diffstat (limited to 'drivers/staging/iio/addac/adt7316-spi.c')
| -rw-r--r-- | drivers/staging/iio/addac/adt7316-spi.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/drivers/staging/iio/addac/adt7316-spi.c b/drivers/staging/iio/addac/adt7316-spi.c new file mode 100644 index 000000000000..369d4d01ed97 --- /dev/null +++ b/drivers/staging/iio/addac/adt7316-spi.c @@ -0,0 +1,180 @@ +/* + * API bus driver for ADT7316/7/8 ADT7516/7/9 digital temperature + * sensor, ADC and DAC + * + * Copyright 2010 Analog Devices Inc. + * + * Licensed under the GPL-2 or later. + */ + +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/spi/spi.h> + +#include "adt7316.h" + +#define ADT7316_SPI_MAX_FREQ_HZ 5000000 +#define ADT7316_SPI_CMD_READ 0x91 +#define ADT7316_SPI_CMD_WRITE 0x90 + +/* + * adt7316 register access by SPI + */ + +static int adt7316_spi_multi_read(void *client, u8 reg, u8 count, u8 *data) +{ + struct spi_device *spi_dev = client; + u8 cmd[2]; + int ret = 0; + + if (count > ADT7316_REG_MAX_ADDR) + count = ADT7316_REG_MAX_ADDR; + + cmd[0] = ADT7316_SPI_CMD_WRITE; + cmd[1] = reg; + + ret = spi_write(spi_dev, cmd, 2); + if (ret < 0) { + dev_err(&spi_dev->dev, "SPI fail to select reg\n"); + return ret; + } + + cmd[0] = ADT7316_SPI_CMD_READ; + + ret = spi_write_then_read(spi_dev, cmd, 1, data, count); + if (ret < 0) { + dev_err(&spi_dev->dev, "SPI read data error\n"); + return ret; + } + + return 0; +} + +static int adt7316_spi_multi_write(void *client, u8 reg, u8 count, u8 *data) +{ + struct spi_device *spi_dev = client; + u8 buf[ADT7316_REG_MAX_ADDR + 2]; + int i, ret = 0; + + if (count > ADT7316_REG_MAX_ADDR) + count = ADT7316_REG_MAX_ADDR; + + buf[0] = ADT7316_SPI_CMD_WRITE; + buf[1] = reg; + for (i = 0; i < count; i++) + buf[i + 2] = data[i]; + + ret = spi_write(spi_dev, buf, count + 2); + if (ret < 0) { + dev_err(&spi_dev->dev, "SPI write error\n"); + return ret; + } + + return ret; +} + +static int adt7316_spi_read(void *client, u8 reg, u8 *data) +{ + return adt7316_spi_multi_read(client, reg, 1, data); +} + +static int adt7316_spi_write(void *client, u8 reg, u8 val) +{ + return adt7316_spi_multi_write(client, reg, 1, &val); +} + +/* + * device probe and remove + */ + +static int __devinit adt7316_spi_probe(struct spi_device *spi_dev) +{ + struct adt7316_bus bus = { + .client = spi_dev, + .irq = spi_dev->irq, + .irq_flags = IRQF_TRIGGER_LOW, + .read = adt7316_spi_read, + .write = adt7316_spi_write, + .multi_read = adt7316_spi_multi_read, + .multi_write = adt7316_spi_multi_write, + }; + + /* don't exceed max specified SPI CLK frequency */ + if (spi_dev->max_speed_hz > ADT7316_SPI_MAX_FREQ_HZ) { + dev_err(&spi_dev->dev, "SPI CLK %d Hz?\n", + spi_dev->max_speed_hz); + return -EINVAL; + } + + /* switch from default I2C protocol to SPI protocol */ + adt7316_spi_write(spi_dev, 0, 0); + adt7316_spi_write(spi_dev, 0, 0); + adt7316_spi_write(spi_dev, 0, 0); + + return adt7316_probe(&spi_dev->dev, &bus, spi_dev->modalias); +} + +static int __devexit adt7316_spi_remove(struct spi_device *spi_dev) +{ + return adt7316_remove(&spi_dev->dev); +} + +static const struct spi_device_id adt7316_spi_id[] = { + { "adt7316", 0 }, + { "adt7317", 0 }, + { "adt7318", 0 }, + { "adt7516", 0 }, + { "adt7517", 0 }, + { "adt7519", 0 }, + { } +}; + +MODULE_DEVICE_TABLE(spi, adt7316_spi_id); + +#ifdef CONFIG_PM +static int adt7316_spi_suspend(struct spi_device *spi_dev, pm_message_t message) +{ + return adt7316_disable(&spi_dev->dev); +} + +static int adt7316_spi_resume(struct spi_device *spi_dev) +{ + return adt7316_enable(&spi_dev->dev); +} +#else +# define adt7316_spi_suspend NULL +# define adt7316_spi_resume NULL +#endif + +static struct spi_driver adt7316_driver = { + .driver = { + .name = "adt7316", + .bus = &spi_bus_type, + .owner = THIS_MODULE, + }, + .probe = adt7316_spi_probe, + .remove = __devexit_p(adt7316_spi_remove), + .suspend = adt7316_spi_suspend, + .resume = adt7316_spi_resume, + .id_table = adt7316_spi_id, +}; + +static __init int adt7316_spi_init(void) +{ + return spi_register_driver(&adt7316_driver); +} + +static __exit void adt7316_spi_exit(void) +{ + spi_unregister_driver(&adt7316_driver); +} + +MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>"); +MODULE_DESCRIPTION("SPI bus driver for Analog Devices ADT7316/7/8 and" + "ADT7516/7/9 digital temperature sensor, ADC and DAC"); +MODULE_LICENSE("GPL v2"); + +module_init(adt7316_spi_init); +module_exit(adt7316_spi_exit); |