1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * FB driver for the HX8347D LCD Controller
4 *
5 * Copyright (C) 2013 Christian Vogelgsang
6 *
7 * Based on driver code found here: https://github.com/watterott/r61505u-Adapter
8 */
9
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/delay.h>
14
15 #include "fbtft.h"
16
17 #define DRVNAME "fb_hx8347d"
18 #define WIDTH 320
19 #define HEIGHT 240
20 #define DEFAULT_GAMMA "0 0 0 0 0 0 0 0 0 0 0 0 0 0\n" \
21 "0 0 0 0 0 0 0 0 0 0 0 0 0 0"
22
init_display(struct fbtft_par * par)23 static int init_display(struct fbtft_par *par)
24 {
25 par->fbtftops.reset(par);
26
27 /* driving ability */
28 write_reg(par, 0xEA, 0x00);
29 write_reg(par, 0xEB, 0x20);
30 write_reg(par, 0xEC, 0x0C);
31 write_reg(par, 0xED, 0xC4);
32 write_reg(par, 0xE8, 0x40);
33 write_reg(par, 0xE9, 0x38);
34 write_reg(par, 0xF1, 0x01);
35 write_reg(par, 0xF2, 0x10);
36 write_reg(par, 0x27, 0xA3);
37
38 /* power voltage */
39 write_reg(par, 0x1B, 0x1B);
40 write_reg(par, 0x1A, 0x01);
41 write_reg(par, 0x24, 0x2F);
42 write_reg(par, 0x25, 0x57);
43
44 /* VCOM offset */
45 write_reg(par, 0x23, 0x8D); /* for flicker adjust */
46
47 /* power on */
48 write_reg(par, 0x18, 0x36);
49 write_reg(par, 0x19, 0x01); /* start osc */
50 write_reg(par, 0x01, 0x00); /* wakeup */
51 write_reg(par, 0x1F, 0x88);
52 mdelay(5);
53 write_reg(par, 0x1F, 0x80);
54 mdelay(5);
55 write_reg(par, 0x1F, 0x90);
56 mdelay(5);
57 write_reg(par, 0x1F, 0xD0);
58 mdelay(5);
59
60 /* color selection */
61 write_reg(par, 0x17, 0x05); /* 65k */
62
63 /*panel characteristic */
64 write_reg(par, 0x36, 0x00);
65
66 /*display on */
67 write_reg(par, 0x28, 0x38);
68 mdelay(40);
69 write_reg(par, 0x28, 0x3C);
70
71 /* orientation */
72 write_reg(par, 0x16, 0x60 | (par->bgr << 3));
73
74 return 0;
75 }
76
set_addr_win(struct fbtft_par * par,int xs,int ys,int xe,int ye)77 static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
78 {
79 write_reg(par, 0x02, (xs >> 8) & 0xFF);
80 write_reg(par, 0x03, xs & 0xFF);
81 write_reg(par, 0x04, (xe >> 8) & 0xFF);
82 write_reg(par, 0x05, xe & 0xFF);
83 write_reg(par, 0x06, (ys >> 8) & 0xFF);
84 write_reg(par, 0x07, ys & 0xFF);
85 write_reg(par, 0x08, (ye >> 8) & 0xFF);
86 write_reg(par, 0x09, ye & 0xFF);
87 write_reg(par, 0x22);
88 }
89
90 /*
91 * Gamma string format:
92 * VRP0 VRP1 VRP2 VRP3 VRP4 VRP5 PRP0 PRP1 PKP0 PKP1 PKP2 PKP3 PKP4 CGM
93 * VRN0 VRN1 VRN2 VRN3 VRN4 VRN5 PRN0 PRN1 PKN0 PKN1 PKN2 PKN3 PKN4 CGM
94 */
95 #define CURVE(num, idx) curves[(num) * par->gamma.num_values + (idx)]
set_gamma(struct fbtft_par * par,u32 * curves)96 static int set_gamma(struct fbtft_par *par, u32 *curves)
97 {
98 static const unsigned long mask[] = {
99 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x7f, 0x7f, 0x1f, 0x1f,
100 0x1f, 0x1f, 0x1f, 0x0f,
101 };
102 int i, j;
103 int acc = 0;
104
105 /* apply mask */
106 for (i = 0; i < par->gamma.num_curves; i++)
107 for (j = 0; j < par->gamma.num_values; j++) {
108 acc += CURVE(i, j);
109 CURVE(i, j) &= mask[j];
110 }
111
112 if (acc == 0) /* skip if all values are zero */
113 return 0;
114
115 for (i = 0; i < par->gamma.num_curves; i++) {
116 write_reg(par, 0x40 + (i * 0x10), CURVE(i, 0));
117 write_reg(par, 0x41 + (i * 0x10), CURVE(i, 1));
118 write_reg(par, 0x42 + (i * 0x10), CURVE(i, 2));
119 write_reg(par, 0x43 + (i * 0x10), CURVE(i, 3));
120 write_reg(par, 0x44 + (i * 0x10), CURVE(i, 4));
121 write_reg(par, 0x45 + (i * 0x10), CURVE(i, 5));
122 write_reg(par, 0x46 + (i * 0x10), CURVE(i, 6));
123 write_reg(par, 0x47 + (i * 0x10), CURVE(i, 7));
124 write_reg(par, 0x48 + (i * 0x10), CURVE(i, 8));
125 write_reg(par, 0x49 + (i * 0x10), CURVE(i, 9));
126 write_reg(par, 0x4A + (i * 0x10), CURVE(i, 10));
127 write_reg(par, 0x4B + (i * 0x10), CURVE(i, 11));
128 write_reg(par, 0x4C + (i * 0x10), CURVE(i, 12));
129 }
130 write_reg(par, 0x5D, (CURVE(1, 0) << 4) | CURVE(0, 0));
131
132 return 0;
133 }
134
135 #undef CURVE
136
137 static struct fbtft_display display = {
138 .regwidth = 8,
139 .width = WIDTH,
140 .height = HEIGHT,
141 .gamma_num = 2,
142 .gamma_len = 14,
143 .gamma = DEFAULT_GAMMA,
144 .fbtftops = {
145 .init_display = init_display,
146 .set_addr_win = set_addr_win,
147 .set_gamma = set_gamma,
148 },
149 };
150
151 FBTFT_REGISTER_DRIVER(DRVNAME, "himax,hx8347d", &display);
152
153 MODULE_ALIAS("spi:" DRVNAME);
154 MODULE_ALIAS("platform:" DRVNAME);
155 MODULE_ALIAS("spi:hx8347d");
156 MODULE_ALIAS("platform:hx8347d");
157
158 MODULE_DESCRIPTION("FB driver for the HX8347D LCD Controller");
159 MODULE_AUTHOR("Christian Vogelgsang");
160 MODULE_LICENSE("GPL");
161
