1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * AD7879/AD7889 touchscreen (SPI bus)
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun #include <linux/input.h> /* BUS_SPI */
9*4882a593Smuzhiyun #include <linux/pm.h>
10*4882a593Smuzhiyun #include <linux/spi/spi.h>
11*4882a593Smuzhiyun #include <linux/module.h>
12*4882a593Smuzhiyun #include <linux/of.h>
13*4882a593Smuzhiyun #include <linux/regmap.h>
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun #include "ad7879.h"
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun #define AD7879_DEVID 0x7A /* AD7879/AD7889 */
18*4882a593Smuzhiyun
19*4882a593Smuzhiyun #define MAX_SPI_FREQ_HZ 5000000
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun #define AD7879_CMD_MAGIC 0xE0
22*4882a593Smuzhiyun #define AD7879_CMD_READ BIT(2)
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun static const struct regmap_config ad7879_spi_regmap_config = {
25*4882a593Smuzhiyun .reg_bits = 16,
26*4882a593Smuzhiyun .val_bits = 16,
27*4882a593Smuzhiyun .max_register = 15,
28*4882a593Smuzhiyun .read_flag_mask = AD7879_CMD_MAGIC | AD7879_CMD_READ,
29*4882a593Smuzhiyun .write_flag_mask = AD7879_CMD_MAGIC,
30*4882a593Smuzhiyun };
31*4882a593Smuzhiyun
ad7879_spi_probe(struct spi_device * spi)32*4882a593Smuzhiyun static int ad7879_spi_probe(struct spi_device *spi)
33*4882a593Smuzhiyun {
34*4882a593Smuzhiyun struct regmap *regmap;
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun /* don't exceed max specified SPI CLK frequency */
37*4882a593Smuzhiyun if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
38*4882a593Smuzhiyun dev_err(&spi->dev, "SPI CLK %d Hz?\n", spi->max_speed_hz);
39*4882a593Smuzhiyun return -EINVAL;
40*4882a593Smuzhiyun }
41*4882a593Smuzhiyun
42*4882a593Smuzhiyun regmap = devm_regmap_init_spi(spi, &ad7879_spi_regmap_config);
43*4882a593Smuzhiyun if (IS_ERR(regmap))
44*4882a593Smuzhiyun return PTR_ERR(regmap);
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun return ad7879_probe(&spi->dev, regmap, spi->irq, BUS_SPI, AD7879_DEVID);
47*4882a593Smuzhiyun }
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun #ifdef CONFIG_OF
50*4882a593Smuzhiyun static const struct of_device_id ad7879_spi_dt_ids[] = {
51*4882a593Smuzhiyun { .compatible = "adi,ad7879", },
52*4882a593Smuzhiyun { }
53*4882a593Smuzhiyun };
54*4882a593Smuzhiyun MODULE_DEVICE_TABLE(of, ad7879_spi_dt_ids);
55*4882a593Smuzhiyun #endif
56*4882a593Smuzhiyun
57*4882a593Smuzhiyun static struct spi_driver ad7879_spi_driver = {
58*4882a593Smuzhiyun .driver = {
59*4882a593Smuzhiyun .name = "ad7879",
60*4882a593Smuzhiyun .pm = &ad7879_pm_ops,
61*4882a593Smuzhiyun .of_match_table = of_match_ptr(ad7879_spi_dt_ids),
62*4882a593Smuzhiyun },
63*4882a593Smuzhiyun .probe = ad7879_spi_probe,
64*4882a593Smuzhiyun };
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun module_spi_driver(ad7879_spi_driver);
67*4882a593Smuzhiyun
68*4882a593Smuzhiyun MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
69*4882a593Smuzhiyun MODULE_DESCRIPTION("AD7879(-1) touchscreen SPI bus driver");
70*4882a593Smuzhiyun MODULE_LICENSE("GPL");
71*4882a593Smuzhiyun MODULE_ALIAS("spi:ad7879");
72