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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");
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
13#include "ad7879.h"
14
15#define AD7879_DEVID 0x7A /* AD7879/AD7889 */
16
17#define MAX_SPI_FREQ_HZ 5000000
18#define AD7879_CMD_MAGIC 0xE000
19#define AD7879_CMD_READ (1 << 10)
20#define AD7879_CMD(reg) (AD7879_CMD_MAGIC | ((reg) & 0xF))
21#define AD7879_WRITECMD(reg) (AD7879_CMD(reg))
22#define AD7879_READCMD(reg) (AD7879_CMD(reg) | AD7879_CMD_READ)
23
24#ifdef CONFIG_PM_SLEEP
25static int ad7879_spi_suspend(struct device *dev)
26{
27 struct spi_device *spi = to_spi_device(dev);
28 struct ad7879 *ts = spi_get_drvdata(spi);
29
30 ad7879_suspend(ts);
31
32 return 0;
33}
34
35static int ad7879_spi_resume(struct device *dev)
36{
37 struct spi_device *spi = to_spi_device(dev);
38 struct ad7879 *ts = spi_get_drvdata(spi);
39
40 ad7879_resume(ts);
41
42 return 0;
43}
44#endif
45
46static SIMPLE_DEV_PM_OPS(ad7879_spi_pm, ad7879_spi_suspend, ad7879_spi_resume);
47
48/*
49 * ad7879_read/write are only used for initial setup and for sysfs controls.
50 * The main traffic is done in ad7879_collect().
51 */
52
53static int ad7879_spi_xfer(struct spi_device *spi,
54 u16 cmd, u8 count, u16 *tx_buf, u16 *rx_buf)
55{
56 struct spi_message msg;
57 struct spi_transfer *xfers;
58 void *spi_data;
59 u16 *command;
60 u16 *_rx_buf = _rx_buf; /* shut gcc up */
61 u8 idx;
62 int ret;
63
64 xfers = spi_data = kzalloc(sizeof(*xfers) * (count + 2), GFP_KERNEL);
65 if (!spi_data)
66 return -ENOMEM;
67
68 spi_message_init(&msg);
69
70 command = spi_data;
71 command[0] = cmd;
72 if (count == 1) {
73 /* ad7879_spi_{read,write} gave us buf on stack */
74 command[1] = *tx_buf;
75 tx_buf = &command[1];
76 _rx_buf = rx_buf;
77 rx_buf = &command[2];
78 }
79
80 ++xfers;
81 xfers[0].tx_buf = command;
82 xfers[0].len = 2;
83 spi_message_add_tail(&xfers[0], &msg);
84 ++xfers;
85
86 for (idx = 0; idx < count; ++idx) {
87 if (rx_buf)
88 xfers[idx].rx_buf = &rx_buf[idx];
89 if (tx_buf)
90 xfers[idx].tx_buf = &tx_buf[idx];
91 xfers[idx].len = 2;
92 spi_message_add_tail(&xfers[idx], &msg);
93 }
94
95 ret = spi_sync(spi, &msg);
96
97 if (count == 1)
98 _rx_buf[0] = command[2];
99
100 kfree(spi_data);
101
102 return ret;
103}
104
105static int ad7879_spi_multi_read(struct device *dev,
106 u8 first_reg, u8 count, u16 *buf)
107{
108 struct spi_device *spi = to_spi_device(dev);
109
110 return ad7879_spi_xfer(spi, AD7879_READCMD(first_reg), count, NULL, buf);
111}
112
113static int ad7879_spi_read(struct device *dev, u8 reg)
114{
115 struct spi_device *spi = to_spi_device(dev);
116 u16 ret, dummy;
117
118 return ad7879_spi_xfer(spi, AD7879_READCMD(reg), 1, &dummy, &ret) ? : ret;
119}
120
121static int ad7879_spi_write(struct device *dev, u8 reg, u16 val)
122{
123 struct spi_device *spi = to_spi_device(dev);
124 u16 dummy;
125
126 return ad7879_spi_xfer(spi, AD7879_WRITECMD(reg), 1, &val, &dummy);
127}
128
129static const struct ad7879_bus_ops ad7879_spi_bus_ops = {
130 .bustype = BUS_SPI,
131 .read = ad7879_spi_read,
132 .multi_read = ad7879_spi_multi_read,
133 .write = ad7879_spi_write,
134};
135
136static int __devinit ad7879_spi_probe(struct spi_device *spi)
137{
138 struct ad7879 *ts;
139 int err;
140
141 /* don't exceed max specified SPI CLK frequency */
142 if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
143 dev_err(&spi->dev, "SPI CLK %d Hz?\n", spi->max_speed_hz);
144 return -EINVAL;
145 }
146
147 spi->bits_per_word = 16;
148 err = spi_setup(spi);
149 if (err) {
150 dev_dbg(&spi->dev, "spi master doesn't support 16 bits/word\n");
151 return err;
152 }
153
154 ts = ad7879_probe(&spi->dev, AD7879_DEVID, spi->irq, &ad7879_spi_bus_ops);
155 if (IS_ERR(ts))
156 return PTR_ERR(ts);
157
158 spi_set_drvdata(spi, ts);
159
160 return 0;
161}
162
163static int __devexit ad7879_spi_remove(struct spi_device *spi)
164{
165 struct ad7879 *ts = spi_get_drvdata(spi);
166
167 ad7879_remove(ts);
168 spi_set_drvdata(spi, NULL);
169
170 return 0;
171}
172
173static struct spi_driver ad7879_spi_driver = {
174 .driver = {
175 .name = "ad7879",
176 .bus = &spi_bus_type,
177 .owner = THIS_MODULE,
178 .pm = &ad7879_spi_pm,
179 },
180 .probe = ad7879_spi_probe,
181 .remove = __devexit_p(ad7879_spi_remove),
182};
183
184static int __init ad7879_spi_init(void)
185{
186 return spi_register_driver(&ad7879_spi_driver);
187}
188module_init(ad7879_spi_init);
189
190static void __exit ad7879_spi_exit(void)
191{
192 spi_unregister_driver(&ad7879_spi_driver);
193}
194module_exit(ad7879_spi_exit);
195
196MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
197MODULE_DESCRIPTION("AD7879(-1) touchscreen SPI bus driver");
198MODULE_LICENSE("GPL");
199MODULE_ALIAS("spi:ad7879");