adxl34x-spi.c
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/*
* ADLX345/346 Three-Axis Digital Accelerometers (SPI Interface)
*
* Enter bugs at http://blackfin.uclinux.org/
*
* Copyright (C) 2009 Michael Hennerich, Analog Devices Inc.
* Licensed under the GPL-2 or later.
*/
#include <linux/input.h> /* BUS_SPI */
#include <linux/module.h>
#include <linux/spi/spi.h>
#include <linux/pm.h>
#include <linux/types.h>
#include "adxl34x.h"
#define MAX_SPI_FREQ_HZ 5000000
#define MAX_FREQ_NO_FIFODELAY 1500000
#define ADXL34X_CMD_MULTB (1 << 6)
#define ADXL34X_CMD_READ (1 << 7)
#define ADXL34X_WRITECMD(reg) (reg & 0x3F)
#define ADXL34X_READCMD(reg) (ADXL34X_CMD_READ | (reg & 0x3F))
#define ADXL34X_READMB_CMD(reg) (ADXL34X_CMD_READ | ADXL34X_CMD_MULTB \
| (reg & 0x3F))
static int adxl34x_spi_read(struct device *dev, unsigned char reg)
{
struct spi_device *spi = to_spi_device(dev);
unsigned char cmd;
cmd = ADXL34X_READCMD(reg);
return spi_w8r8(spi, cmd);
}
static int adxl34x_spi_write(struct device *dev,
unsigned char reg, unsigned char val)
{
struct spi_device *spi = to_spi_device(dev);
unsigned char buf[2];
buf[0] = ADXL34X_WRITECMD(reg);
buf[1] = val;
return spi_write(spi, buf, sizeof(buf));
}
static int adxl34x_spi_read_block(struct device *dev,
unsigned char reg, int count,
void *buf)
{
struct spi_device *spi = to_spi_device(dev);
ssize_t status;
reg = ADXL34X_READMB_CMD(reg);
status = spi_write_then_read(spi, ®, 1, buf, count);
return (status < 0) ? status : 0;
}
static const struct adxl34x_bus_ops adxl34x_spi_bops = {
.bustype = BUS_SPI,
.write = adxl34x_spi_write,
.read = adxl34x_spi_read,
.read_block = adxl34x_spi_read_block,
};
static int adxl34x_spi_probe(struct spi_device *spi)
{
struct adxl34x *ac;
/* don't exceed max specified SPI CLK frequency */
if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
dev_err(&spi->dev, "SPI CLK %d Hz too fast\n", spi->max_speed_hz);
return -EINVAL;
}
ac = adxl34x_probe(&spi->dev, spi->irq,
spi->max_speed_hz > MAX_FREQ_NO_FIFODELAY,
&adxl34x_spi_bops);
if (IS_ERR(ac))
return PTR_ERR(ac);
spi_set_drvdata(spi, ac);
return 0;
}
static int adxl34x_spi_remove(struct spi_device *spi)
{
struct adxl34x *ac = spi_get_drvdata(spi);
return adxl34x_remove(ac);
}
static int __maybe_unused adxl34x_spi_suspend(struct device *dev)
{
struct spi_device *spi = to_spi_device(dev);
struct adxl34x *ac = spi_get_drvdata(spi);
adxl34x_suspend(ac);
return 0;
}
static int __maybe_unused adxl34x_spi_resume(struct device *dev)
{
struct spi_device *spi = to_spi_device(dev);
struct adxl34x *ac = spi_get_drvdata(spi);
adxl34x_resume(ac);
return 0;
}
static SIMPLE_DEV_PM_OPS(adxl34x_spi_pm, adxl34x_spi_suspend,
adxl34x_spi_resume);
static struct spi_driver adxl34x_driver = {
.driver = {
.name = "adxl34x",
.pm = &adxl34x_spi_pm,
},
.probe = adxl34x_spi_probe,
.remove = adxl34x_spi_remove,
};
module_spi_driver(adxl34x_driver);
MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("ADXL345/346 Three-Axis Digital Accelerometer SPI Bus Driver");
MODULE_LICENSE("GPL");