1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Goodix Berlin Touchscreen Driver
4 *
5 * Copyright (C) 2020 - 2021 Goodix, Inc.
6 * Copyright (C) 2023 Linaro Ltd.
7 *
8 * Based on goodix_ts_berlin driver.
9 */
10 #include <linux/unaligned.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/regmap.h>
14 #include <linux/spi/spi.h>
15 #include <linux/input.h>
16
17 #include "goodix_berlin.h"
18
19 #define GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN 1
20 #define GOODIX_BERLIN_REGISTER_WIDTH 4
21 #define GOODIX_BERLIN_SPI_READ_DUMMY_LEN_A 4
22 #define GOODIX_BERLIN_SPI_READ_DUMMY_LEN_D 3
23 #define GOODIX_BERLIN_SPI_READ_PREFIX_LEN_A (GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN + \
24 GOODIX_BERLIN_REGISTER_WIDTH + \
25 GOODIX_BERLIN_SPI_READ_DUMMY_LEN_A)
26 #define GOODIX_BERLIN_SPI_READ_PREFIX_LEN_D (GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN + \
27 GOODIX_BERLIN_REGISTER_WIDTH + \
28 GOODIX_BERLIN_SPI_READ_DUMMY_LEN_D)
29 #define GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN (GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN + \
30 GOODIX_BERLIN_REGISTER_WIDTH)
31
32 #define GOODIX_BERLIN_SPI_WRITE_FLAG 0xF0
33 #define GOODIX_BERLIN_SPI_READ_FLAG 0xF1
34
goodix_berlin_spi_read(void * context,const void * reg_buf,size_t reg_size,void * val_buf,size_t val_size)35 static int goodix_berlin_spi_read(void *context, const void *reg_buf,
36 size_t reg_size, void *val_buf,
37 size_t val_size)
38 {
39 struct spi_device *spi = context;
40 const struct goodix_berlin_ic_data *ic_data = spi_get_device_match_data(spi);
41 struct spi_transfer xfers;
42 struct spi_message spi_msg;
43 const u32 *reg = reg_buf; /* reg is stored as native u32 at start of buffer */
44 int error;
45
46 if (reg_size != GOODIX_BERLIN_REGISTER_WIDTH)
47 return -EINVAL;
48
49 u8 *buf __free(kfree) =
50 kzalloc(ic_data->read_prefix_len + val_size, GFP_KERNEL);
51 if (!buf)
52 return -ENOMEM;
53
54 spi_message_init(&spi_msg);
55 memset(&xfers, 0, sizeof(xfers));
56
57 /* buffer format: 0xF1 + addr(4bytes) + dummy(3/4bytes) + data */
58 buf[0] = GOODIX_BERLIN_SPI_READ_FLAG;
59 put_unaligned_be32(*reg, buf + GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN);
60 memset(buf + GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN + GOODIX_BERLIN_REGISTER_WIDTH,
61 0xff, ic_data->read_dummy_len);
62
63 xfers.tx_buf = buf;
64 xfers.rx_buf = buf;
65 xfers.len = ic_data->read_prefix_len + val_size;
66 xfers.cs_change = 0;
67 spi_message_add_tail(&xfers, &spi_msg);
68
69 error = spi_sync(spi, &spi_msg);
70 if (error < 0) {
71 dev_err(&spi->dev, "spi transfer error, %d", error);
72 return error;
73 }
74
75 memcpy(val_buf, buf + ic_data->read_prefix_len, val_size);
76 return error;
77 }
78
goodix_berlin_spi_write(void * context,const void * data,size_t count)79 static int goodix_berlin_spi_write(void *context, const void *data,
80 size_t count)
81 {
82 unsigned int len = count - GOODIX_BERLIN_REGISTER_WIDTH;
83 struct spi_device *spi = context;
84 struct spi_transfer xfers;
85 struct spi_message spi_msg;
86 const u32 *reg = data; /* reg is stored as native u32 at start of buffer */
87 int error;
88
89 u8 *buf __free(kfree) =
90 kzalloc(GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN + len, GFP_KERNEL);
91 if (!buf)
92 return -ENOMEM;
93
94 spi_message_init(&spi_msg);
95 memset(&xfers, 0, sizeof(xfers));
96
97 buf[0] = GOODIX_BERLIN_SPI_WRITE_FLAG;
98 put_unaligned_be32(*reg, buf + GOODIX_BERLIN_SPI_TRANS_PREFIX_LEN);
99 memcpy(buf + GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN,
100 data + GOODIX_BERLIN_REGISTER_WIDTH, len);
101
102 xfers.tx_buf = buf;
103 xfers.len = GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN + len;
104 xfers.cs_change = 0;
105 spi_message_add_tail(&xfers, &spi_msg);
106
107 error = spi_sync(spi, &spi_msg);
108 if (error < 0) {
109 dev_err(&spi->dev, "spi transfer error, %d", error);
110 return error;
111 }
112
113 return 0;
114 }
115
116 static const struct regmap_config goodix_berlin_spi_regmap_conf = {
117 .reg_bits = 32,
118 .val_bits = 8,
119 .read = goodix_berlin_spi_read,
120 .write = goodix_berlin_spi_write,
121 };
122
123 /* vendor & product left unassigned here, should probably be updated from fw info */
124 static const struct input_id goodix_berlin_spi_input_id = {
125 .bustype = BUS_SPI,
126 };
127
goodix_berlin_spi_probe(struct spi_device * spi)128 static int goodix_berlin_spi_probe(struct spi_device *spi)
129 {
130 const struct goodix_berlin_ic_data *ic_data = spi_get_device_match_data(spi);
131 struct regmap_config regmap_config;
132 struct regmap *regmap;
133 size_t max_size;
134 int error = 0;
135
136 spi->mode = SPI_MODE_0;
137 spi->bits_per_word = 8;
138 error = spi_setup(spi);
139 if (error)
140 return error;
141
142 max_size = spi_max_transfer_size(spi);
143
144 regmap_config = goodix_berlin_spi_regmap_conf;
145 regmap_config.max_raw_read = max_size - ic_data->read_prefix_len;
146 regmap_config.max_raw_write = max_size - GOODIX_BERLIN_SPI_WRITE_PREFIX_LEN;
147
148 regmap = devm_regmap_init(&spi->dev, NULL, spi, ®map_config);
149 if (IS_ERR(regmap))
150 return PTR_ERR(regmap);
151
152 error = goodix_berlin_probe(&spi->dev, spi->irq,
153 &goodix_berlin_spi_input_id, regmap,
154 ic_data);
155 if (error)
156 return error;
157
158 return 0;
159 }
160
161 static const struct goodix_berlin_ic_data gt9897_data = {
162 .fw_version_info_addr = GOODIX_BERLIN_FW_VERSION_INFO_ADDR_A,
163 .ic_info_addr = GOODIX_BERLIN_IC_INFO_ADDR_A,
164 .read_dummy_len = GOODIX_BERLIN_SPI_READ_DUMMY_LEN_A,
165 .read_prefix_len = GOODIX_BERLIN_SPI_READ_PREFIX_LEN_A,
166 };
167
168 static const struct goodix_berlin_ic_data gt9916_data = {
169 .fw_version_info_addr = GOODIX_BERLIN_FW_VERSION_INFO_ADDR_D,
170 .ic_info_addr = GOODIX_BERLIN_IC_INFO_ADDR_D,
171 .read_dummy_len = GOODIX_BERLIN_SPI_READ_DUMMY_LEN_D,
172 .read_prefix_len = GOODIX_BERLIN_SPI_READ_PREFIX_LEN_D,
173 };
174
175 static const struct spi_device_id goodix_berlin_spi_ids[] = {
176 { .name = "gt9897", .driver_data = (long)>9897_data },
177 { .name = "gt9916", .driver_data = (long)>9916_data },
178 { },
179 };
180 MODULE_DEVICE_TABLE(spi, goodix_berlin_spi_ids);
181
182 static const struct of_device_id goodix_berlin_spi_of_match[] = {
183 { .compatible = "goodix,gt9897", .data = >9897_data },
184 { .compatible = "goodix,gt9916", .data = >9916_data },
185 { }
186 };
187 MODULE_DEVICE_TABLE(of, goodix_berlin_spi_of_match);
188
189 static struct spi_driver goodix_berlin_spi_driver = {
190 .driver = {
191 .name = "goodix-berlin-spi",
192 .of_match_table = goodix_berlin_spi_of_match,
193 .pm = pm_sleep_ptr(&goodix_berlin_pm_ops),
194 .dev_groups = goodix_berlin_groups,
195 },
196 .probe = goodix_berlin_spi_probe,
197 .id_table = goodix_berlin_spi_ids,
198 };
199 module_spi_driver(goodix_berlin_spi_driver);
200
201 MODULE_LICENSE("GPL");
202 MODULE_DESCRIPTION("Goodix Berlin SPI Touchscreen driver");
203 MODULE_AUTHOR("Neil Armstrong <neil.armstrong@linaro.org>");
204