1 // SPDX-License-Identifier: GPL-2.0
2 /* Driver for ORISE Technology OTM3225A SOC for TFT LCD
3 * Copyright (C) 2017, EETS GmbH, Felix Brack <fb@ltec.ch>
4 *
5 * This driver implements a lcd device for the ORISE OTM3225A display
6 * controller. The control interface to the display is SPI and the display's
7 * memory is updated over the 16-bit RGB interface.
8 * The main source of information for writing this driver was provided by the
9 * OTM3225A datasheet from ORISE Technology. Some information arise from the
10 * ILI9328 datasheet from ILITEK as well as from the datasheets and sample code
11 * provided by Crystalfontz America Inc. who sells the CFAF240320A-032T, a 3.2"
12 * TFT LC display using the OTM3225A controller.
13 */
14
15 #include <linux/delay.h>
16 #include <linux/device.h>
17 #include <linux/kernel.h>
18 #include <linux/lcd.h>
19 #include <linux/module.h>
20 #include <linux/spi/spi.h>
21
22 #define OTM3225A_INDEX_REG 0x70
23 #define OTM3225A_DATA_REG 0x72
24
25 /* instruction register list */
26 #define DRIVER_OUTPUT_CTRL_1 0x01
27 #define DRIVER_WAVEFORM_CTRL 0x02
28 #define ENTRY_MODE 0x03
29 #define SCALING_CTRL 0x04
30 #define DISPLAY_CTRL_1 0x07
31 #define DISPLAY_CTRL_2 0x08
32 #define DISPLAY_CTRL_3 0x09
33 #define FRAME_CYCLE_CTRL 0x0A
34 #define EXT_DISP_IFACE_CTRL_1 0x0C
35 #define FRAME_MAKER_POS 0x0D
36 #define EXT_DISP_IFACE_CTRL_2 0x0F
37 #define POWER_CTRL_1 0x10
38 #define POWER_CTRL_2 0x11
39 #define POWER_CTRL_3 0x12
40 #define POWER_CTRL_4 0x13
41 #define GRAM_ADDR_HORIZ_SET 0x20
42 #define GRAM_ADDR_VERT_SET 0x21
43 #define GRAM_READ_WRITE 0x22
44 #define POWER_CTRL_7 0x29
45 #define FRAME_RATE_CTRL 0x2B
46 #define GAMMA_CTRL_1 0x30
47 #define GAMMA_CTRL_2 0x31
48 #define GAMMA_CTRL_3 0x32
49 #define GAMMA_CTRL_4 0x35
50 #define GAMMA_CTRL_5 0x36
51 #define GAMMA_CTRL_6 0x37
52 #define GAMMA_CTRL_7 0x38
53 #define GAMMA_CTRL_8 0x39
54 #define GAMMA_CTRL_9 0x3C
55 #define GAMMA_CTRL_10 0x3D
56 #define WINDOW_HORIZ_RAM_START 0x50
57 #define WINDOW_HORIZ_RAM_END 0x51
58 #define WINDOW_VERT_RAM_START 0x52
59 #define WINDOW_VERT_RAM_END 0x53
60 #define DRIVER_OUTPUT_CTRL_2 0x60
61 #define BASE_IMG_DISPLAY_CTRL 0x61
62 #define VERT_SCROLL_CTRL 0x6A
63 #define PD1_DISPLAY_POS 0x80
64 #define PD1_RAM_START 0x81
65 #define PD1_RAM_END 0x82
66 #define PD2_DISPLAY_POS 0x83
67 #define PD2_RAM_START 0x84
68 #define PD2_RAM_END 0x85
69 #define PANEL_IFACE_CTRL_1 0x90
70 #define PANEL_IFACE_CTRL_2 0x92
71 #define PANEL_IFACE_CTRL_4 0x95
72 #define PANEL_IFACE_CTRL_5 0x97
73
74 struct otm3225a_data {
75 struct spi_device *spi;
76 struct lcd_device *ld;
77 int power;
78 };
79
80 struct otm3225a_spi_instruction {
81 unsigned char reg; /* register to write */
82 unsigned short value; /* data to write to 'reg' */
83 unsigned short delay; /* delay in ms after write */
84 };
85
86 static struct otm3225a_spi_instruction display_init[] = {
87 { DRIVER_OUTPUT_CTRL_1, 0x0000, 0 },
88 { DRIVER_WAVEFORM_CTRL, 0x0700, 0 },
89 { ENTRY_MODE, 0x50A0, 0 },
90 { SCALING_CTRL, 0x0000, 0 },
91 { DISPLAY_CTRL_2, 0x0606, 0 },
92 { DISPLAY_CTRL_3, 0x0000, 0 },
93 { FRAME_CYCLE_CTRL, 0x0000, 0 },
94 { EXT_DISP_IFACE_CTRL_1, 0x0000, 0 },
95 { FRAME_MAKER_POS, 0x0000, 0 },
96 { EXT_DISP_IFACE_CTRL_2, 0x0002, 0 },
97 { POWER_CTRL_2, 0x0007, 0 },
98 { POWER_CTRL_3, 0x0000, 0 },
99 { POWER_CTRL_4, 0x0000, 200 },
100 { DISPLAY_CTRL_1, 0x0101, 0 },
101 { POWER_CTRL_1, 0x12B0, 0 },
102 { POWER_CTRL_2, 0x0007, 0 },
103 { POWER_CTRL_3, 0x01BB, 50 },
104 { POWER_CTRL_4, 0x0013, 0 },
105 { POWER_CTRL_7, 0x0010, 50 },
106 { GAMMA_CTRL_1, 0x000A, 0 },
107 { GAMMA_CTRL_2, 0x1326, 0 },
108 { GAMMA_CTRL_3, 0x0A29, 0 },
109 { GAMMA_CTRL_4, 0x0A0A, 0 },
110 { GAMMA_CTRL_5, 0x1E03, 0 },
111 { GAMMA_CTRL_6, 0x031E, 0 },
112 { GAMMA_CTRL_7, 0x0706, 0 },
113 { GAMMA_CTRL_8, 0x0303, 0 },
114 { GAMMA_CTRL_9, 0x010E, 0 },
115 { GAMMA_CTRL_10, 0x040E, 0 },
116 { WINDOW_HORIZ_RAM_START, 0x0000, 0 },
117 { WINDOW_HORIZ_RAM_END, 0x00EF, 0 },
118 { WINDOW_VERT_RAM_START, 0x0000, 0 },
119 { WINDOW_VERT_RAM_END, 0x013F, 0 },
120 { DRIVER_OUTPUT_CTRL_2, 0x2700, 0 },
121 { BASE_IMG_DISPLAY_CTRL, 0x0001, 0 },
122 { VERT_SCROLL_CTRL, 0x0000, 0 },
123 { PD1_DISPLAY_POS, 0x0000, 0 },
124 { PD1_RAM_START, 0x0000, 0 },
125 { PD1_RAM_END, 0x0000, 0 },
126 { PD2_DISPLAY_POS, 0x0000, 0 },
127 { PD2_RAM_START, 0x0000, 0 },
128 { PD2_RAM_END, 0x0000, 0 },
129 { PANEL_IFACE_CTRL_1, 0x0010, 0 },
130 { PANEL_IFACE_CTRL_2, 0x0000, 0 },
131 { PANEL_IFACE_CTRL_4, 0x0210, 0 },
132 { PANEL_IFACE_CTRL_5, 0x0000, 0 },
133 { DISPLAY_CTRL_1, 0x0133, 0 },
134 };
135
136 static struct otm3225a_spi_instruction display_enable_rgb_interface[] = {
137 { ENTRY_MODE, 0x1080, 0 },
138 { GRAM_ADDR_HORIZ_SET, 0x0000, 0 },
139 { GRAM_ADDR_VERT_SET, 0x0000, 0 },
140 { EXT_DISP_IFACE_CTRL_1, 0x0111, 500 },
141 };
142
143 static struct otm3225a_spi_instruction display_off[] = {
144 { DISPLAY_CTRL_1, 0x0131, 100 },
145 { DISPLAY_CTRL_1, 0x0130, 100 },
146 { DISPLAY_CTRL_1, 0x0100, 0 },
147 { POWER_CTRL_1, 0x0280, 0 },
148 { POWER_CTRL_3, 0x018B, 0 },
149 };
150
151 static struct otm3225a_spi_instruction display_on[] = {
152 { POWER_CTRL_1, 0x1280, 0 },
153 { DISPLAY_CTRL_1, 0x0101, 100 },
154 { DISPLAY_CTRL_1, 0x0121, 0 },
155 { DISPLAY_CTRL_1, 0x0123, 100 },
156 { DISPLAY_CTRL_1, 0x0133, 10 },
157 };
158
otm3225a_write(struct spi_device * spi,struct otm3225a_spi_instruction * instruction,unsigned int count)159 static void otm3225a_write(struct spi_device *spi,
160 struct otm3225a_spi_instruction *instruction,
161 unsigned int count)
162 {
163 unsigned char buf[3];
164
165 while (count--) {
166 /* address register using index register */
167 buf[0] = OTM3225A_INDEX_REG;
168 buf[1] = 0x00;
169 buf[2] = instruction->reg;
170 spi_write(spi, buf, 3);
171
172 /* write data to addressed register */
173 buf[0] = OTM3225A_DATA_REG;
174 buf[1] = (instruction->value >> 8) & 0xff;
175 buf[2] = instruction->value & 0xff;
176 spi_write(spi, buf, 3);
177
178 /* execute delay if any */
179 if (instruction->delay)
180 msleep(instruction->delay);
181 instruction++;
182 }
183 }
184
otm3225a_set_power(struct lcd_device * ld,int power)185 static int otm3225a_set_power(struct lcd_device *ld, int power)
186 {
187 struct otm3225a_data *dd = lcd_get_data(ld);
188
189 if (power == dd->power)
190 return 0;
191
192 if (power > LCD_POWER_ON)
193 otm3225a_write(dd->spi, display_off, ARRAY_SIZE(display_off));
194 else
195 otm3225a_write(dd->spi, display_on, ARRAY_SIZE(display_on));
196 dd->power = power;
197
198 return 0;
199 }
200
otm3225a_get_power(struct lcd_device * ld)201 static int otm3225a_get_power(struct lcd_device *ld)
202 {
203 struct otm3225a_data *dd = lcd_get_data(ld);
204
205 return dd->power;
206 }
207
208 static const struct lcd_ops otm3225a_ops = {
209 .set_power = otm3225a_set_power,
210 .get_power = otm3225a_get_power,
211 };
212
otm3225a_probe(struct spi_device * spi)213 static int otm3225a_probe(struct spi_device *spi)
214 {
215 struct otm3225a_data *dd;
216 struct lcd_device *ld;
217 struct device *dev = &spi->dev;
218
219 dd = devm_kzalloc(dev, sizeof(struct otm3225a_data), GFP_KERNEL);
220 if (dd == NULL)
221 return -ENOMEM;
222
223 ld = devm_lcd_device_register(dev, dev_name(dev), dev, dd,
224 &otm3225a_ops);
225 if (IS_ERR(ld))
226 return PTR_ERR(ld);
227
228 dd->spi = spi;
229 dd->ld = ld;
230 dev_set_drvdata(dev, dd);
231
232 dev_info(dev, "Initializing and switching to RGB interface");
233 otm3225a_write(spi, display_init, ARRAY_SIZE(display_init));
234 otm3225a_write(spi, display_enable_rgb_interface,
235 ARRAY_SIZE(display_enable_rgb_interface));
236 return 0;
237 }
238
239 static struct spi_driver otm3225a_driver = {
240 .driver = {
241 .name = "otm3225a",
242 },
243 .probe = otm3225a_probe,
244 };
245
246 module_spi_driver(otm3225a_driver);
247
248 MODULE_AUTHOR("Felix Brack <fb@ltec.ch>");
249 MODULE_DESCRIPTION("OTM3225A TFT LCD driver");
250 MODULE_VERSION("1.0.0");
251 MODULE_LICENSE("GPL v2");
252