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/*
* 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;
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;
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 adt7316_spi_probe(struct spi_device *spi_dev)
{
struct adt7316_bus bus = {
.client = spi_dev,
.irq = spi_dev->irq,
.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 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);
static struct spi_driver adt7316_driver = {
.driver = {
.name = "adt7316",
.pm = ADT7316_PM_OPS,
},
.probe = adt7316_spi_probe,
.id_table = adt7316_spi_id,
};
module_spi_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");
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