/drivers/staging/iio/addac/adt7316-spi.c
https://bitbucket.org/wisechild/galaxy-nexus · C · 180 lines · 131 code · 33 blank · 16 comment · 7 complexity · 13484eec0955312ac08b585504574282 MD5 · raw file
- /*
- * 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);