1 // SPDX-License-Identifier: GPL-2.0
2
3 #include <linux/device.h>
4 #include <linux/module.h>
5 #include <linux/spi/spi.h>
6 #include <linux/delay.h>
7
8 #include <drm/drm_print.h>
9
10 #include "panel-samsung-s6e63m0.h"
11
12 #define DATA_MASK 0x100
13
s6e63m0_spi_dcs_read(struct device * dev,const u8 cmd,u8 * data)14 static int s6e63m0_spi_dcs_read(struct device *dev, const u8 cmd, u8 *data)
15 {
16 /*
17 * FIXME: implement reading DCS commands over SPI so we can
18 * properly identify which physical panel is connected.
19 */
20 *data = 0;
21
22 return 0;
23 }
24
s6e63m0_spi_write_word(struct device * dev,u16 data)25 static int s6e63m0_spi_write_word(struct device *dev, u16 data)
26 {
27 struct spi_device *spi = to_spi_device(dev);
28 struct spi_transfer xfer = {
29 .len = 2,
30 .tx_buf = &data,
31 };
32 struct spi_message msg;
33
34 spi_message_init(&msg);
35 spi_message_add_tail(&xfer, &msg);
36
37 return spi_sync(spi, &msg);
38 }
39
s6e63m0_spi_dcs_write(struct device * dev,const u8 * data,size_t len)40 static int s6e63m0_spi_dcs_write(struct device *dev, const u8 *data, size_t len)
41 {
42 int ret = 0;
43
44 dev_dbg(dev, "SPI writing dcs seq: %*ph\n", (int)len, data);
45 ret = s6e63m0_spi_write_word(dev, *data);
46
47 while (!ret && --len) {
48 ++data;
49 ret = s6e63m0_spi_write_word(dev, *data | DATA_MASK);
50 }
51
52 if (ret) {
53 dev_err(dev, "SPI error %d writing dcs seq: %*ph\n", ret,
54 (int)len, data);
55 }
56
57 usleep_range(300, 310);
58
59 return ret;
60 }
61
s6e63m0_spi_probe(struct spi_device * spi)62 static int s6e63m0_spi_probe(struct spi_device *spi)
63 {
64 struct device *dev = &spi->dev;
65 int ret;
66
67 spi->bits_per_word = 9;
68 spi->mode = SPI_MODE_3;
69 ret = spi_setup(spi);
70 if (ret < 0) {
71 dev_err(dev, "spi setup failed.\n");
72 return ret;
73 }
74 return s6e63m0_probe(dev, s6e63m0_spi_dcs_read, s6e63m0_spi_dcs_write,
75 false);
76 }
77
s6e63m0_spi_remove(struct spi_device * spi)78 static int s6e63m0_spi_remove(struct spi_device *spi)
79 {
80 return s6e63m0_remove(&spi->dev);
81 }
82
83 static const struct of_device_id s6e63m0_spi_of_match[] = {
84 { .compatible = "samsung,s6e63m0" },
85 { /* sentinel */ }
86 };
87 MODULE_DEVICE_TABLE(of, s6e63m0_spi_of_match);
88
89 static struct spi_driver s6e63m0_spi_driver = {
90 .probe = s6e63m0_spi_probe,
91 .remove = s6e63m0_spi_remove,
92 .driver = {
93 .name = "panel-samsung-s6e63m0",
94 .of_match_table = s6e63m0_spi_of_match,
95 },
96 };
97 module_spi_driver(s6e63m0_spi_driver);
98
99 MODULE_AUTHOR("Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com>");
100 MODULE_DESCRIPTION("s6e63m0 LCD SPI Driver");
101 MODULE_LICENSE("GPL v2");
102
