1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * AD7879/AD7889 touchscreen (SPI bus)
4 *
5 * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
6 */
7
8#include <linux/input.h>	/* BUS_SPI */
9#include <linux/pm.h>
10#include <linux/spi/spi.h>
11#include <linux/module.h>
12#include <linux/of.h>
13#include <linux/regmap.h>
14
15#include "ad7879.h"
16
17#define AD7879_DEVID		0x7A	/* AD7879/AD7889 */
18
19#define MAX_SPI_FREQ_HZ      5000000
20
21#define AD7879_CMD_MAGIC     0xE0
22#define AD7879_CMD_READ      BIT(2)
23
24static const struct regmap_config ad7879_spi_regmap_config = {
25	.reg_bits = 16,
26	.val_bits = 16,
27	.max_register = 15,
28	.read_flag_mask = AD7879_CMD_MAGIC | AD7879_CMD_READ,
29	.write_flag_mask = AD7879_CMD_MAGIC,
30};
31
32static int ad7879_spi_probe(struct spi_device *spi)
33{
34	struct regmap *regmap;
35
36	/* don't exceed max specified SPI CLK frequency */
37	if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
38		dev_err(&spi->dev, "SPI CLK %d Hz?\n", spi->max_speed_hz);
39		return -EINVAL;
40	}
41
42	regmap = devm_regmap_init_spi(spi, &ad7879_spi_regmap_config);
43	if (IS_ERR(regmap))
44		return PTR_ERR(regmap);
45
46	return ad7879_probe(&spi->dev, regmap, spi->irq, BUS_SPI, AD7879_DEVID);
47}
48
49#ifdef CONFIG_OF
50static const struct of_device_id ad7879_spi_dt_ids[] = {
51	{ .compatible = "adi,ad7879", },
52	{ }
53};
54MODULE_DEVICE_TABLE(of, ad7879_spi_dt_ids);
55#endif
56
57static struct spi_driver ad7879_spi_driver = {
58	.driver = {
59		.name		= "ad7879",
60		.dev_groups	= ad7879_groups,
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