1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * FB driver for the ILI9340 LCD Controller
4 *
5 * Copyright (C) 2013 Noralf Tronnes
6 */
7
8 #include <linux/module.h>
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/delay.h>
12 #include <video/mipi_display.h>
13
14 #include "fbtft.h"
15
16 #define DRVNAME "fb_ili9340"
17 #define WIDTH 240
18 #define HEIGHT 320
19
20 /* Init sequence taken from: Arduino Library for the Adafruit 2.2" display */
init_display(struct fbtft_par * par)21 static int init_display(struct fbtft_par *par)
22 {
23 par->fbtftops.reset(par);
24
25 write_reg(par, 0xEF, 0x03, 0x80, 0x02);
26 write_reg(par, 0xCF, 0x00, 0XC1, 0X30);
27 write_reg(par, 0xED, 0x64, 0x03, 0X12, 0X81);
28 write_reg(par, 0xE8, 0x85, 0x00, 0x78);
29 write_reg(par, 0xCB, 0x39, 0x2C, 0x00, 0x34, 0x02);
30 write_reg(par, 0xF7, 0x20);
31 write_reg(par, 0xEA, 0x00, 0x00);
32
33 /* Power Control 1 */
34 write_reg(par, 0xC0, 0x23);
35
36 /* Power Control 2 */
37 write_reg(par, 0xC1, 0x10);
38
39 /* VCOM Control 1 */
40 write_reg(par, 0xC5, 0x3e, 0x28);
41
42 /* VCOM Control 2 */
43 write_reg(par, 0xC7, 0x86);
44
45 /* COLMOD: Pixel Format Set */
46 /* 16 bits/pixel */
47 write_reg(par, MIPI_DCS_SET_PIXEL_FORMAT, 0x55);
48
49 /* Frame Rate Control */
50 /* Division ratio = fosc, Frame Rate = 79Hz */
51 write_reg(par, 0xB1, 0x00, 0x18);
52
53 /* Display Function Control */
54 write_reg(par, 0xB6, 0x08, 0x82, 0x27);
55
56 /* Gamma Function Disable */
57 write_reg(par, 0xF2, 0x00);
58
59 /* Gamma curve selection */
60 write_reg(par, MIPI_DCS_SET_GAMMA_CURVE, 0x01);
61
62 /* Positive Gamma Correction */
63 write_reg(par, 0xE0,
64 0x0F, 0x31, 0x2B, 0x0C, 0x0E, 0x08, 0x4E, 0xF1,
65 0x37, 0x07, 0x10, 0x03, 0x0E, 0x09, 0x00);
66
67 /* Negative Gamma Correction */
68 write_reg(par, 0xE1,
69 0x00, 0x0E, 0x14, 0x03, 0x11, 0x07, 0x31, 0xC1,
70 0x48, 0x08, 0x0F, 0x0C, 0x31, 0x36, 0x0F);
71
72 write_reg(par, MIPI_DCS_EXIT_SLEEP_MODE);
73
74 mdelay(120);
75
76 write_reg(par, MIPI_DCS_SET_DISPLAY_ON);
77
78 return 0;
79 }
80
set_addr_win(struct fbtft_par * par,int xs,int ys,int xe,int ye)81 static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
82 {
83 write_reg(par, MIPI_DCS_SET_COLUMN_ADDRESS,
84 xs >> 8, xs & 0xFF, xe >> 8, xe & 0xFF);
85
86 write_reg(par, MIPI_DCS_SET_PAGE_ADDRESS,
87 ys >> 8, ys & 0xFF, ye >> 8, ye & 0xFF);
88
89 write_reg(par, MIPI_DCS_WRITE_MEMORY_START);
90 }
91
92 #define ILI9340_MADCTL_MV 0x20
93 #define ILI9340_MADCTL_MX 0x40
94 #define ILI9340_MADCTL_MY 0x80
set_var(struct fbtft_par * par)95 static int set_var(struct fbtft_par *par)
96 {
97 u8 val;
98
99 switch (par->info->var.rotate) {
100 case 270:
101 val = ILI9340_MADCTL_MV;
102 break;
103 case 180:
104 val = ILI9340_MADCTL_MY;
105 break;
106 case 90:
107 val = ILI9340_MADCTL_MV | ILI9340_MADCTL_MY | ILI9340_MADCTL_MX;
108 break;
109 default:
110 val = ILI9340_MADCTL_MX;
111 break;
112 }
113 /* Memory Access Control */
114 write_reg(par, MIPI_DCS_SET_ADDRESS_MODE, val | (par->bgr << 3));
115
116 return 0;
117 }
118
119 static struct fbtft_display display = {
120 .regwidth = 8,
121 .width = WIDTH,
122 .height = HEIGHT,
123 .fbtftops = {
124 .init_display = init_display,
125 .set_addr_win = set_addr_win,
126 .set_var = set_var,
127 },
128 };
129
130 FBTFT_REGISTER_DRIVER(DRVNAME, "ilitek,ili9340", &display);
131
132 MODULE_ALIAS("spi:" DRVNAME);
133 MODULE_ALIAS("platform:" DRVNAME);
134 MODULE_ALIAS("spi:ili9340");
135 MODULE_ALIAS("platform:ili9340");
136
137 MODULE_DESCRIPTION("FB driver for the ILI9340 LCD Controller");
138 MODULE_AUTHOR("Noralf Tronnes");
139 MODULE_LICENSE("GPL");
140