1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* DRM driver for Solomon SSD13xx OLED displays (SPI bus)
*
* Copyright 2022 Red Hat Inc.
* Authors: Javier Martinez Canillas <javierm@redhat.com>
*/
#include <linux/spi/spi.h>
#include <linux/module.h>
#include "ssd130x.h"
#define DRIVER_NAME "ssd130x-spi"
#define DRIVER_DESC "DRM driver for Solomon SSD13xx OLED displays (SPI)"
struct ssd130x_spi_transport {
struct spi_device *spi;
struct gpio_desc *dc;
};
/*
* The regmap bus .write handler, it is just a wrapper around spi_write()
* but toggling the Data/Command control pin (D/C#). Since for 4-wire SPI
* a D/C# pin is used, in contrast with I2C where a control byte is sent,
* prior to every data byte, that contains a bit with the D/C# value.
*
* These control bytes are considered registers by the ssd130x core driver
* and can be used by the ssd130x SPI driver to determine if the data sent
* is for a command register or for the Graphic Display Data RAM (GDDRAM).
*/
static int ssd130x_spi_write(void *context, const void *data, size_t count)
{
struct ssd130x_spi_transport *t = context;
struct spi_device *spi = t->spi;
const u8 *reg = data;
if (*reg == SSD13XX_COMMAND)
gpiod_set_value_cansleep(t->dc, 0);
if (*reg == SSD13XX_DATA)
gpiod_set_value_cansleep(t->dc, 1);
/* Remove control byte since is not used in a 4-wire SPI interface */
return spi_write(spi, reg + 1, count - 1);
}
/* The ssd130x driver does not read registers but regmap expects a .read */
static int ssd130x_spi_read(void *context, const void *reg, size_t reg_size,
void *val, size_t val_size)
{
return -EOPNOTSUPP;
}
static const struct regmap_config ssd130x_spi_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.write = ssd130x_spi_write,
.read = ssd130x_spi_read,
.can_multi_write = true,
};
static int ssd130x_spi_probe(struct spi_device *spi)
{
struct ssd130x_spi_transport *t;
struct ssd130x_device *ssd130x;
struct regmap *regmap;
struct gpio_desc *dc;
struct device *dev = &spi->dev;
dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW);
if (IS_ERR(dc))
return dev_err_probe(dev, PTR_ERR(dc),
"Failed to get dc gpio\n");
t = devm_kzalloc(dev, sizeof(*t), GFP_KERNEL);
if (!t)
return dev_err_probe(dev, -ENOMEM,
"Failed to allocate SPI transport data\n");
t->spi = spi;
t->dc = dc;
regmap = devm_regmap_init(dev, NULL, t, &ssd130x_spi_regmap_config);
if (IS_ERR(regmap))
return PTR_ERR(regmap);
ssd130x = ssd130x_probe(dev, regmap);
if (IS_ERR(ssd130x))
return PTR_ERR(ssd130x);
spi_set_drvdata(spi, ssd130x);
return 0;
}
static void ssd130x_spi_remove(struct spi_device *spi)
{
struct ssd130x_device *ssd130x = spi_get_drvdata(spi);
ssd130x_remove(ssd130x);
}
static void ssd130x_spi_shutdown(struct spi_device *spi)
{
struct ssd130x_device *ssd130x = spi_get_drvdata(spi);
ssd130x_shutdown(ssd130x);
}
static const struct of_device_id ssd130x_of_match[] = {
/* ssd130x family */
{
.compatible = "sinowealth,sh1106",
.data = &ssd130x_variants[SH1106_ID],
},
{
.compatible = "solomon,ssd1305",
.data = &ssd130x_variants[SSD1305_ID],
},
{
.compatible = "solomon,ssd1306",
.data = &ssd130x_variants[SSD1306_ID],
},
{
.compatible = "solomon,ssd1307",
.data = &ssd130x_variants[SSD1307_ID],
},
{
.compatible = "solomon,ssd1309",
.data = &ssd130x_variants[SSD1309_ID],
},
/* ssd132x family */
{
.compatible = "solomon,ssd1322",
.data = &ssd130x_variants[SSD1322_ID],
},
{
.compatible = "solomon,ssd1325",
.data = &ssd130x_variants[SSD1325_ID],
},
{
.compatible = "solomon,ssd1327",
.data = &ssd130x_variants[SSD1327_ID],
},
/* ssd133x family */
{
.compatible = "solomon,ssd1331",
.data = &ssd130x_variants[SSD1331_ID],
},
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, ssd130x_of_match);
#if IS_MODULE(CONFIG_DRM_SSD130X_SPI)
/*
* The SPI core always reports a MODALIAS uevent of the form "spi:<dev>", even
* if the device was registered via OF. This means that the module will not be
* auto loaded, unless it contains an alias that matches the MODALIAS reported.
*
* To workaround this issue, add a SPI device ID table. Even when this should
* not be needed for this driver to match the registered SPI devices.
*/
static const struct spi_device_id ssd130x_spi_table[] = {
/* ssd130x family */
{ "sh1106", SH1106_ID },
{ "ssd1305", SSD1305_ID },
{ "ssd1306", SSD1306_ID },
{ "ssd1307", SSD1307_ID },
{ "ssd1309", SSD1309_ID },
/* ssd132x family */
{ "ssd1322", SSD1322_ID },
{ "ssd1325", SSD1325_ID },
{ "ssd1327", SSD1327_ID },
/* ssd133x family */
{ "ssd1331", SSD1331_ID },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(spi, ssd130x_spi_table);
#endif
static struct spi_driver ssd130x_spi_driver = {
.driver = {
.name = DRIVER_NAME,
.of_match_table = ssd130x_of_match,
},
.probe = ssd130x_spi_probe,
.remove = ssd130x_spi_remove,
.shutdown = ssd130x_spi_shutdown,
};
module_spi_driver(ssd130x_spi_driver);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("Javier Martinez Canillas <javierm@redhat.com>");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS(DRM_SSD130X);
|
