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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
14#include "ad7879.h"
15
16#define AD7879_DEVID 0x7A /* AD7879/AD7889 */
17
18#define MAX_SPI_FREQ_HZ 5000000
19#define AD7879_CMD_MAGIC 0xE000
20#define AD7879_CMD_READ (1 << 10)
21#define AD7879_CMD(reg) (AD7879_CMD_MAGIC | ((reg) & 0xF))
22#define AD7879_WRITECMD(reg) (AD7879_CMD(reg))
23#define AD7879_READCMD(reg) (AD7879_CMD(reg) | AD7879_CMD_READ)
24
25/*
26 * ad7879_read/write are only used for initial setup and for sysfs controls.
27 * The main traffic is done in ad7879_collect().
28 */
29
30static int ad7879_spi_xfer(struct spi_device *spi,
31 u16 cmd, u8 count, u16 *tx_buf, u16 *rx_buf)
32{
33 struct spi_message msg;
34 struct spi_transfer *xfers;
35 void *spi_data;
36 u16 *command;
37 u16 *_rx_buf = _rx_buf; /* shut gcc up */
38 u8 idx;
39 int ret;
40
41 xfers = spi_data = kzalloc(sizeof(*xfers) * (count + 2), GFP_KERNEL);
42 if (!spi_data)
43 return -ENOMEM;
44
45 spi_message_init(&msg);
46
47 command = spi_data;
48 command[0] = cmd;
49 if (count == 1) {
50 /* ad7879_spi_{read,write} gave us buf on stack */
51 command[1] = *tx_buf;
52 tx_buf = &command[1];
53 _rx_buf = rx_buf;
54 rx_buf = &command[2];
55 }
56
57 ++xfers;
58 xfers[0].tx_buf = command;
59 xfers[0].len = 2;
60 spi_message_add_tail(&xfers[0], &msg);
61 ++xfers;
62
63 for (idx = 0; idx < count; ++idx) {
64 if (rx_buf)
65 xfers[idx].rx_buf = &rx_buf[idx];
66 if (tx_buf)
67 xfers[idx].tx_buf = &tx_buf[idx];
68 xfers[idx].len = 2;
69 spi_message_add_tail(&xfers[idx], &msg);
70 }
71
72 ret = spi_sync(spi, &msg);
73
74 if (count == 1)
75 _rx_buf[0] = command[2];
76
77 kfree(spi_data);
78
79 return ret;
80}
81
82static int ad7879_spi_multi_read(struct device *dev,
83 u8 first_reg, u8 count, u16 *buf)
84{
85 struct spi_device *spi = to_spi_device(dev);
86
87 return ad7879_spi_xfer(spi, AD7879_READCMD(first_reg), count, NULL, buf);
88}
89
90static int ad7879_spi_read(struct device *dev, u8 reg)
91{
92 struct spi_device *spi = to_spi_device(dev);
93 u16 ret, dummy;
94
95 return ad7879_spi_xfer(spi, AD7879_READCMD(reg), 1, &dummy, &ret) ? : ret;
96}
97
98static int ad7879_spi_write(struct device *dev, u8 reg, u16 val)
99{
100 struct spi_device *spi = to_spi_device(dev);
101 u16 dummy;
102
103 return ad7879_spi_xfer(spi, AD7879_WRITECMD(reg), 1, &val, &dummy);
104}
105
106static const struct ad7879_bus_ops ad7879_spi_bus_ops = {
107 .bustype = BUS_SPI,
108 .read = ad7879_spi_read,
109 .multi_read = ad7879_spi_multi_read,
110 .write = ad7879_spi_write,
111};
112
113static int ad7879_spi_probe(struct spi_device *spi)
114{
115 struct ad7879 *ts;
116 int err;
117
118 /* don't exceed max specified SPI CLK frequency */
119 if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
120 dev_err(&spi->dev, "SPI CLK %d Hz?\n", spi->max_speed_hz);
121 return -EINVAL;
122 }
123
124 spi->bits_per_word = 16;
125 err = spi_setup(spi);
126 if (err) {
127 dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n");
128 return err;
129 }
130
131 ts = ad7879_probe(&spi->dev, AD7879_DEVID, spi->irq, &ad7879_spi_bus_ops);
132 if (IS_ERR(ts))
133 return PTR_ERR(ts);
134
135 spi_set_drvdata(spi, ts);
136
137 return 0;
138}
139
140static int ad7879_spi_remove(struct spi_device *spi)
141{
142 struct ad7879 *ts = spi_get_drvdata(spi);
143
144 ad7879_remove(ts);
145
146 return 0;
147}
148
149static struct spi_driver ad7879_spi_driver = {
150 .driver = {
151 .name = "ad7879",
152 .owner = THIS_MODULE,
153 .pm = &ad7879_pm_ops,
154 },
155 .probe = ad7879_spi_probe,
156 .remove = ad7879_spi_remove,
157};
158
159module_spi_driver(ad7879_spi_driver);
160
161MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
162MODULE_DESCRIPTION("AD7879(-1) touchscreen SPI bus driver");
163MODULE_LICENSE("GPL");
164MODULE_ALIAS("spi:ad7879");
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 .pm = &ad7879_pm_ops,
61 .of_match_table = of_match_ptr(ad7879_spi_dt_ids),
62 },
63 .probe = ad7879_spi_probe,
64};
65
66module_spi_driver(ad7879_spi_driver);
67
68MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
69MODULE_DESCRIPTION("AD7879(-1) touchscreen SPI bus driver");
70MODULE_LICENSE("GPL");
71MODULE_ALIAS("spi:ad7879");