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 return 0;
72 }
73
set_addr_win(struct fbtft_par * par,int xs,int ys,int xe,int ye)74 static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
75 {
76 write_reg(par, 0x02, (xs >> 8) & 0xFF);
77 write_reg(par, 0x03, xs & 0xFF);
78 write_reg(par, 0x04, (xe >> 8) & 0xFF);
79 write_reg(par, 0x05, xe & 0xFF);
80 write_reg(par, 0x06, (ys >> 8) & 0xFF);
81 write_reg(par, 0x07, ys & 0xFF);
82 write_reg(par, 0x08, (ye >> 8) & 0xFF);
83 write_reg(par, 0x09, ye & 0xFF);
84 write_reg(par, 0x22);
85 }
86
87 #define MEM_Y BIT(7) /* MY row address order */
88 #define MEM_X BIT(6) /* MX column address order */
89 #define MEM_V BIT(5) /* MV row / column exchange */
90 #define MEM_L BIT(4) /* ML vertical refresh order */
91 #define MEM_BGR (3) /* RGB-BGR Order */
set_var(struct fbtft_par * par)92 static int set_var(struct fbtft_par *par)
93 {
94 switch (par->info->var.rotate) {
95 case 0:
96 write_reg(par, 0x16, MEM_V | MEM_X | (par->bgr << MEM_BGR));
97 break;
98 case 270:
99 write_reg(par, 0x16, par->bgr << MEM_BGR);
100 break;
101 case 180:
102 write_reg(par, 0x16, MEM_V | MEM_Y | (par->bgr << MEM_BGR));
103 break;
104 case 90:
105 write_reg(par, 0x16, MEM_X | MEM_Y | (par->bgr << MEM_BGR));
106 break;
107 }
108
109 return 0;
110 }
111
112 /*
113 * Gamma string format:
114 * VRP0 VRP1 VRP2 VRP3 VRP4 VRP5 PRP0 PRP1 PKP0 PKP1 PKP2 PKP3 PKP4 CGM
115 * VRN0 VRN1 VRN2 VRN3 VRN4 VRN5 PRN0 PRN1 PKN0 PKN1 PKN2 PKN3 PKN4 CGM
116 */
117 #define CURVE(num, idx) curves[(num) * par->gamma.num_values + (idx)]
set_gamma(struct fbtft_par * par,u32 * curves)118 static int set_gamma(struct fbtft_par *par, u32 *curves)
119 {
120 static const unsigned long mask[] = {
121 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x7f, 0x7f, 0x1f, 0x1f,
122 0x1f, 0x1f, 0x1f, 0x0f,
123 };
124 int i, j;
125 int acc = 0;
126
127 /* apply mask */
128 for (i = 0; i < par->gamma.num_curves; i++)
129 for (j = 0; j < par->gamma.num_values; j++) {
130 acc += CURVE(i, j);
131 CURVE(i, j) &= mask[j];
132 }
133
134 if (acc == 0) /* skip if all values are zero */
135 return 0;
136
137 for (i = 0; i < par->gamma.num_curves; i++) {
138 write_reg(par, 0x40 + (i * 0x10), CURVE(i, 0));
139 write_reg(par, 0x41 + (i * 0x10), CURVE(i, 1));
140 write_reg(par, 0x42 + (i * 0x10), CURVE(i, 2));
141 write_reg(par, 0x43 + (i * 0x10), CURVE(i, 3));
142 write_reg(par, 0x44 + (i * 0x10), CURVE(i, 4));
143 write_reg(par, 0x45 + (i * 0x10), CURVE(i, 5));
144 write_reg(par, 0x46 + (i * 0x10), CURVE(i, 6));
145 write_reg(par, 0x47 + (i * 0x10), CURVE(i, 7));
146 write_reg(par, 0x48 + (i * 0x10), CURVE(i, 8));
147 write_reg(par, 0x49 + (i * 0x10), CURVE(i, 9));
148 write_reg(par, 0x4A + (i * 0x10), CURVE(i, 10));
149 write_reg(par, 0x4B + (i * 0x10), CURVE(i, 11));
150 write_reg(par, 0x4C + (i * 0x10), CURVE(i, 12));
151 }
152 write_reg(par, 0x5D, (CURVE(1, 0) << 4) | CURVE(0, 0));
153
154 return 0;
155 }
156
157 #undef CURVE
158
159 static struct fbtft_display display = {
160 .regwidth = 8,
161 .width = WIDTH,
162 .height = HEIGHT,
163 .gamma_num = 2,
164 .gamma_len = 14,
165 .gamma = DEFAULT_GAMMA,
166 .fbtftops = {
167 .init_display = init_display,
168 .set_addr_win = set_addr_win,
169 .set_var = set_var,
170 .set_gamma = set_gamma,
171 },
172 };
173
174 FBTFT_REGISTER_DRIVER(DRVNAME, "himax,hx8347d", &display);
175
176 MODULE_ALIAS("spi:" DRVNAME);
177 MODULE_ALIAS("platform:" DRVNAME);
178 MODULE_ALIAS("spi:hx8347d");
179 MODULE_ALIAS("platform:hx8347d");
180
181 MODULE_DESCRIPTION("FB driver for the HX8347D LCD Controller");
182 MODULE_AUTHOR("Christian Vogelgsang");
183 MODULE_LICENSE("GPL");
184