LXR linux/drivers/input/misc/adxl34x-spi.c

   1/*
   2 * ADLX345/346 Three-Axis Digital Accelerometers (SPI Interface)
   3 *
   4 * Enter bugs at http://blackfin.uclinux.org/
   5 *
   6 * Copyright (C) 2009 Michael Hennerich, Analog Devices Inc.
   7 * Licensed under the GPL-2 or later.
   8 */
   9
  10#include <linux/input.h>        /* BUS_SPI */
  11#include <linux/module.h>
  12#include <linux/spi/spi.h>
  13#include <linux/pm.h>
  14#include <linux/types.h>
  15#include "adxl34x.h"
  16
  17#define MAX_SPI_FREQ_HZ         5000000
  18#define MAX_FREQ_NO_FIFODELAY   1500000
  19#define ADXL34X_CMD_MULTB       (1 << 6)
  20#define ADXL34X_CMD_READ        (1 << 7)
  21#define ADXL34X_WRITECMD(reg)   (reg & 0x3F)
  22#define ADXL34X_READCMD(reg)    (ADXL34X_CMD_READ | (reg & 0x3F))
  23#define ADXL34X_READMB_CMD(reg) (ADXL34X_CMD_READ | ADXL34X_CMD_MULTB \
  24                                        | (reg & 0x3F))
  25
  26static int adxl34x_spi_read(struct device *dev, unsigned char reg)
  27{
  28        struct spi_device *spi = to_spi_device(dev);
  29        unsigned char cmd;
  30
  31        cmd = ADXL34X_READCMD(reg);
  32
  33        return spi_w8r8(spi, cmd);
  34}
  35
  36static int adxl34x_spi_write(struct device *dev,
  37                             unsigned char reg, unsigned char val)
  38{
  39        struct spi_device *spi = to_spi_device(dev);
  40        unsigned char buf[2];
  41
  42        buf[0] = ADXL34X_WRITECMD(reg);
  43        buf[1] = val;
  44
  45        return spi_write(spi, buf, sizeof(buf));
  46}
  47
  48static int adxl34x_spi_read_block(struct device *dev,
  49                                  unsigned char reg, int count,
  50                                  void *buf)
  51{
  52        struct spi_device *spi = to_spi_device(dev);
  53        ssize_t status;
  54
  55        reg = ADXL34X_READMB_CMD(reg);
  56        status = spi_write_then_read(spi, &reg, 1, buf, count);
  57
  58        return (status < 0) ? status : 0;
  59}
  60
  61static const struct adxl34x_bus_ops adxl34x_spi_bops = {
  62        .bustype        = BUS_SPI,
  63        .write          = adxl34x_spi_write,
  64        .read           = adxl34x_spi_read,
  65        .read_block     = adxl34x_spi_read_block,
  66};
  67
  68static int adxl34x_spi_probe(struct spi_device *spi)
  69{
  70        struct adxl34x *ac;
  71
  72        /* don't exceed max specified SPI CLK frequency */
  73        if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
  74                dev_err(&spi->dev, "SPI CLK %d Hz too fast\n", spi->max_speed_hz);
  75                return -EINVAL;
  76        }
  77
  78        ac = adxl34x_probe(&spi->dev, spi->irq,
  79                           spi->max_speed_hz > MAX_FREQ_NO_FIFODELAY,
  80                           &adxl34x_spi_bops);
  81
  82        if (IS_ERR(ac))
  83                return PTR_ERR(ac);
  84
  85        spi_set_drvdata(spi, ac);
  86
  87        return 0;
  88}
  89
  90static int adxl34x_spi_remove(struct spi_device *spi)
  91{
  92        struct adxl34x *ac = spi_get_drvdata(spi);
  93
  94        return adxl34x_remove(ac);
  95}
  96
  97static int __maybe_unused adxl34x_spi_suspend(struct device *dev)
  98{
  99        struct spi_device *spi = to_spi_device(dev);
 100        struct adxl34x *ac = spi_get_drvdata(spi);
 101
 102        adxl34x_suspend(ac);
 103
 104        return 0;
 105}
 106
 107static int __maybe_unused adxl34x_spi_resume(struct device *dev)
 108{
 109        struct spi_device *spi = to_spi_device(dev);
 110        struct adxl34x *ac = spi_get_drvdata(spi);
 111
 112        adxl34x_resume(ac);
 113
 114        return 0;
 115}
 116
 117static SIMPLE_DEV_PM_OPS(adxl34x_spi_pm, adxl34x_spi_suspend,
 118                         adxl34x_spi_resume);
 119
 120static struct spi_driver adxl34x_driver = {
 121        .driver = {
 122                .name = "adxl34x",
 123                .pm = &adxl34x_spi_pm,
 124        },
 125        .probe   = adxl34x_spi_probe,
 126        .remove  = adxl34x_spi_remove,
 127};
 128
 129module_spi_driver(adxl34x_driver);
 130
 131MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 132MODULE_DESCRIPTION("ADXL345/346 Three-Axis Digital Accelerometer SPI Bus Driver");
 133MODULE_LICENSE("GPL");
 134