1 /*
2 * FB driver for the HX8347D LCD Controller
3 *
4 * Copyright (C) 2013 Christian Vogelgsang
5 *
6 * Based on driver code found here: https://github.com/watterott/r61505u-Adapter
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 */
18
19 #include <linux/module.h>
20 #include <linux/kernel.h>
21 #include <linux/init.h>
22 #include <linux/delay.h>
23
24 #include "fbtft.h"
25
26 #define DRVNAME "fb_hx8347d"
27 #define WIDTH 320
28 #define HEIGHT 240
29 #define DEFAULT_GAMMA "0 0 0 0 0 0 0 0 0 0 0 0 0 0\n" \
30 "0 0 0 0 0 0 0 0 0 0 0 0 0 0"
31
init_display(struct fbtft_par * par)32 static int init_display(struct fbtft_par *par)
33 {
34 par->fbtftops.reset(par);
35
36 /* driving ability */
37 write_reg(par, 0xEA, 0x00);
38 write_reg(par, 0xEB, 0x20);
39 write_reg(par, 0xEC, 0x0C);
40 write_reg(par, 0xED, 0xC4);
41 write_reg(par, 0xE8, 0x40);
42 write_reg(par, 0xE9, 0x38);
43 write_reg(par, 0xF1, 0x01);
44 write_reg(par, 0xF2, 0x10);
45 write_reg(par, 0x27, 0xA3);
46
47 /* power voltage */
48 write_reg(par, 0x1B, 0x1B);
49 write_reg(par, 0x1A, 0x01);
50 write_reg(par, 0x24, 0x2F);
51 write_reg(par, 0x25, 0x57);
52
53 /* VCOM offset */
54 write_reg(par, 0x23, 0x8D); /* for flicker adjust */
55
56 /* power on */
57 write_reg(par, 0x18, 0x36);
58 write_reg(par, 0x19, 0x01); /* start osc */
59 write_reg(par, 0x01, 0x00); /* wakeup */
60 write_reg(par, 0x1F, 0x88);
61 mdelay(5);
62 write_reg(par, 0x1F, 0x80);
63 mdelay(5);
64 write_reg(par, 0x1F, 0x90);
65 mdelay(5);
66 write_reg(par, 0x1F, 0xD0);
67 mdelay(5);
68
69 /* color selection */
70 write_reg(par, 0x17, 0x05); /* 65k */
71
72 /*panel characteristic */
73 write_reg(par, 0x36, 0x00);
74
75 /*display on */
76 write_reg(par, 0x28, 0x38);
77 mdelay(40);
78 write_reg(par, 0x28, 0x3C);
79
80 /* orientation */
81 write_reg(par, 0x16, 0x60 | (par->bgr << 3));
82
83 return 0;
84 }
85
set_addr_win(struct fbtft_par * par,int xs,int ys,int xe,int ye)86 static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
87 {
88 write_reg(par, 0x02, (xs >> 8) & 0xFF);
89 write_reg(par, 0x03, xs & 0xFF);
90 write_reg(par, 0x04, (xe >> 8) & 0xFF);
91 write_reg(par, 0x05, xe & 0xFF);
92 write_reg(par, 0x06, (ys >> 8) & 0xFF);
93 write_reg(par, 0x07, ys & 0xFF);
94 write_reg(par, 0x08, (ye >> 8) & 0xFF);
95 write_reg(par, 0x09, ye & 0xFF);
96 write_reg(par, 0x22);
97 }
98
99 /*
100 Gamma string format:
101 VRP0 VRP1 VRP2 VRP3 VRP4 VRP5 PRP0 PRP1 PKP0 PKP1 PKP2 PKP3 PKP4 CGM
102 VRN0 VRN1 VRN2 VRN3 VRN4 VRN5 PRN0 PRN1 PKN0 PKN1 PKN2 PKN3 PKN4 CGM
103 */
104 #define CURVE(num, idx) curves[num * par->gamma.num_values + idx]
set_gamma(struct fbtft_par * par,unsigned long * curves)105 static int set_gamma(struct fbtft_par *par, unsigned long *curves)
106 {
107 unsigned long mask[] = {
108 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x7f, 0x7f, 0x1f, 0x1f,
109 0x1f, 0x1f, 0x1f, 0x0f,
110 };
111 int i, j;
112 int acc = 0;
113
114 /* apply mask */
115 for (i = 0; i < par->gamma.num_curves; i++)
116 for (j = 0; j < par->gamma.num_values; j++) {
117 acc += CURVE(i, j);
118 CURVE(i, j) &= mask[j];
119 }
120
121 if (acc == 0) /* skip if all values are zero */
122 return 0;
123
124 for (i = 0; i < par->gamma.num_curves; i++) {
125 write_reg(par, 0x40 + (i * 0x10), CURVE(i, 0));
126 write_reg(par, 0x41 + (i * 0x10), CURVE(i, 1));
127 write_reg(par, 0x42 + (i * 0x10), CURVE(i, 2));
128 write_reg(par, 0x43 + (i * 0x10), CURVE(i, 3));
129 write_reg(par, 0x44 + (i * 0x10), CURVE(i, 4));
130 write_reg(par, 0x45 + (i * 0x10), CURVE(i, 5));
131 write_reg(par, 0x46 + (i * 0x10), CURVE(i, 6));
132 write_reg(par, 0x47 + (i * 0x10), CURVE(i, 7));
133 write_reg(par, 0x48 + (i * 0x10), CURVE(i, 8));
134 write_reg(par, 0x49 + (i * 0x10), CURVE(i, 9));
135 write_reg(par, 0x4A + (i * 0x10), CURVE(i, 10));
136 write_reg(par, 0x4B + (i * 0x10), CURVE(i, 11));
137 write_reg(par, 0x4C + (i * 0x10), CURVE(i, 12));
138 }
139 write_reg(par, 0x5D, (CURVE(1, 0) << 4) | CURVE(0, 0));
140
141 return 0;
142 }
143 #undef CURVE
144
145 static struct fbtft_display display = {
146 .regwidth = 8,
147 .width = WIDTH,
148 .height = HEIGHT,
149 .gamma_num = 2,
150 .gamma_len = 14,
151 .gamma = DEFAULT_GAMMA,
152 .fbtftops = {
153 .init_display = init_display,
154 .set_addr_win = set_addr_win,
155 .set_gamma = set_gamma,
156 },
157 };
158
159 FBTFT_REGISTER_DRIVER(DRVNAME, "himax,hx8347d", &display);
160
161 MODULE_ALIAS("spi:" DRVNAME);
162 MODULE_ALIAS("platform:" DRVNAME);
163 MODULE_ALIAS("spi:hx8347d");
164 MODULE_ALIAS("platform:hx8347d");
165
166 MODULE_DESCRIPTION("FB driver for the HX8347D LCD Controller");
167 MODULE_AUTHOR("Christian Vogelgsang");
168 MODULE_LICENSE("GPL");
169