LXR linux/drivers/input/touchscreen/ad7879-spi.c

   1/*
   2 * AD7879/AD7889 touchscreen (SPI bus)
   3 *
   4 * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
   5 *
   6 * Licensed under the GPL-2 or later.
   7 */
   8
   9#include <linux/input.h>        /* BUS_SPI */
  10#include <linux/pm.h>
  11#include <linux/spi/spi.h>
  12#include <linux/module.h>
  13#include <linux/of.h>
  14#include <linux/regmap.h>
  15
  16#include "ad7879.h"
  17
  18#define AD7879_DEVID            0x7A    /* AD7879/AD7889 */
  19
  20#define MAX_SPI_FREQ_HZ      5000000
  21
  22#define AD7879_CMD_MAGIC     0xE0
  23#define AD7879_CMD_READ      BIT(2)
  24
  25static const struct regmap_config ad7879_spi_regmap_config = {
  26        .reg_bits = 16,
  27        .val_bits = 16,
  28        .max_register = 15,
  29        .read_flag_mask = AD7879_CMD_MAGIC | AD7879_CMD_READ,
  30        .write_flag_mask = AD7879_CMD_MAGIC,
  31};
  32
  33static int ad7879_spi_probe(struct spi_device *spi)
  34{
  35        struct regmap *regmap;
  36
  37        /* don't exceed max specified SPI CLK frequency */
  38        if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
  39                dev_err(&spi->dev, "SPI CLK %d Hz?\n", spi->max_speed_hz);
  40                return -EINVAL;
  41        }
  42
  43        regmap = devm_regmap_init_spi(spi, &ad7879_spi_regmap_config);
  44        if (IS_ERR(regmap))
  45                return PTR_ERR(regmap);
  46
  47        return ad7879_probe(&spi->dev, regmap, spi->irq, BUS_SPI, AD7879_DEVID);
  48}
  49
  50#ifdef CONFIG_OF
  51static const struct of_device_id ad7879_spi_dt_ids[] = {
  52        { .compatible = "adi,ad7879", },
  53        { }
  54};
  55MODULE_DEVICE_TABLE(of, ad7879_spi_dt_ids);
  56#endif
  57
  58static struct spi_driver ad7879_spi_driver = {
  59        .driver = {
  60                .name   = "ad7879",
  61                .pm     = &ad7879_pm_ops,
  62                .of_match_table = of_match_ptr(ad7879_spi_dt_ids),
  63        },
  64        .probe          = ad7879_spi_probe,
  65};
  66
  67module_spi_driver(ad7879_spi_driver);
  68
  69MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
  70MODULE_DESCRIPTION("AD7879(-1) touchscreen SPI bus driver");
  71MODULE_LICENSE("GPL");
  72MODULE_ALIAS("spi:ad7879");
  73