1/*
2 * FB driver for the ST7735R LCD Controller
3 *
4 * Copyright (C) 2013 Noralf Tronnes
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 */
16
17#include <linux/module.h>
18#include <linux/kernel.h>
19#include <linux/init.h>
20
21#include "fbtft.h"
22
23#define DRVNAME "fb_st7735r"
24#define DEFAULT_GAMMA   "0F 1A 0F 18 2F 28 20 22 1F 1B 23 37 00 07 02 10\n" \
25			"0F 1B 0F 17 33 2C 29 2E 30 30 39 3F 00 07 03 10"
26
27static int default_init_sequence[] = {
28	/* SWRESET - Software reset */
29	-1, 0x01,
30	-2, 150,                               /* delay */
31
32	/* SLPOUT - Sleep out & booster on */
33	-1, 0x11,
34	-2, 500,                               /* delay */
35
36	/* FRMCTR1 - frame rate control: normal mode
37	     frame rate = fosc / (1 x 2 + 40) * (LINE + 2C + 2D) */
38	-1, 0xB1, 0x01, 0x2C, 0x2D,
39
40	/* FRMCTR2 - frame rate control: idle mode
41	     frame rate = fosc / (1 x 2 + 40) * (LINE + 2C + 2D) */
42	-1, 0xB2, 0x01, 0x2C, 0x2D,
43
44	/* FRMCTR3 - frame rate control - partial mode
45	     dot inversion mode, line inversion mode */
46	-1, 0xB3, 0x01, 0x2C, 0x2D, 0x01, 0x2C, 0x2D,
47
48	/* INVCTR - display inversion control
49	     no inversion */
50	-1, 0xB4, 0x07,
51
52	/* PWCTR1 - Power Control
53	     -4.6V, AUTO mode */
54	-1, 0xC0, 0xA2, 0x02, 0x84,
55
56	/* PWCTR2 - Power Control
57	     VGH25 = 2.4C VGSEL = -10 VGH = 3 * AVDD */
58	-1, 0xC1, 0xC5,
59
60	/* PWCTR3 - Power Control
61	     Opamp current small, Boost frequency */
62	-1, 0xC2, 0x0A, 0x00,
63
64	/* PWCTR4 - Power Control
65	     BCLK/2, Opamp current small & Medium low */
66	-1, 0xC3, 0x8A, 0x2A,
67
68	/* PWCTR5 - Power Control */
69	-1, 0xC4, 0x8A, 0xEE,
70
71	/* VMCTR1 - Power Control */
72	-1, 0xC5, 0x0E,
73
74	/* INVOFF - Display inversion off */
75	-1, 0x20,
76
77	/* COLMOD - Interface pixel format */
78	-1, 0x3A, 0x05,
79
80	/* DISPON - Display On */
81	-1, 0x29,
82	-2, 100,                               /* delay */
83
84	/* NORON - Partial off (Normal) */
85	-1, 0x13,
86	-2, 10,                               /* delay */
87
88	/* end marker */
89	-3
90};
91
92static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
93{
94	/* Column address */
95	write_reg(par, 0x2A, xs >> 8, xs & 0xFF, xe >> 8, xe & 0xFF);
96
97	/* Row address */
98	write_reg(par, 0x2B, ys >> 8, ys & 0xFF, ye >> 8, ye & 0xFF);
99
100	/* Memory write */
101	write_reg(par, 0x2C);
102}
103
104#define MY BIT(7)
105#define MX BIT(6)
106#define MV BIT(5)
107static int set_var(struct fbtft_par *par)
108{
109	/* MADCTL - Memory data access control
110	     RGB/BGR:
111	     1. Mode selection pin SRGB
112		RGB H/W pin for color filter setting: 0=RGB, 1=BGR
113	     2. MADCTL RGB bit
114		RGB-BGR ORDER color filter panel: 0=RGB, 1=BGR */
115	switch (par->info->var.rotate) {
116	case 0:
117		write_reg(par, 0x36, MX | MY | (par->bgr << 3));
118		break;
119	case 270:
120		write_reg(par, 0x36, MY | MV | (par->bgr << 3));
121		break;
122	case 180:
123		write_reg(par, 0x36, par->bgr << 3);
124		break;
125	case 90:
126		write_reg(par, 0x36, MX | MV | (par->bgr << 3));
127		break;
128	}
129
130	return 0;
131}
132
133/*
134  Gamma string format:
135    VRF0P VOS0P PK0P PK1P PK2P PK3P PK4P PK5P PK6P PK7P PK8P PK9P SELV0P SELV1P SELV62P SELV63P
136    VRF0N VOS0N PK0N PK1N PK2N PK3N PK4N PK5N PK6N PK7N PK8N PK9N SELV0N SELV1N SELV62N SELV63N
137*/
138#define CURVE(num, idx)  curves[num * par->gamma.num_values + idx]
139static int set_gamma(struct fbtft_par *par, unsigned long *curves)
140{
141	int i, j;
142
143	/* apply mask */
144	for (i = 0; i < par->gamma.num_curves; i++)
145		for (j = 0; j < par->gamma.num_values; j++)
146			CURVE(i, j) &= 0x3f;
147
148	for (i = 0; i < par->gamma.num_curves; i++)
149		write_reg(par, 0xE0 + i,
150			CURVE(i, 0), CURVE(i, 1), CURVE(i, 2), CURVE(i, 3),
151			CURVE(i, 4), CURVE(i, 5), CURVE(i, 6), CURVE(i, 7),
152			CURVE(i, 8), CURVE(i, 9), CURVE(i, 10), CURVE(i, 11),
153			CURVE(i, 12), CURVE(i, 13), CURVE(i, 14), CURVE(i, 15));
154
155	return 0;
156}
157#undef CURVE
158
159static struct fbtft_display display = {
160	.regwidth = 8,
161	.width = 128,
162	.height = 160,
163	.init_sequence = default_init_sequence,
164	.gamma_num = 2,
165	.gamma_len = 16,
166	.gamma = DEFAULT_GAMMA,
167	.fbtftops = {
168		.set_addr_win = set_addr_win,
169		.set_var = set_var,
170		.set_gamma = set_gamma,
171	},
172};
173
174FBTFT_REGISTER_DRIVER(DRVNAME, "sitronix,st7735r", &display);
175
176MODULE_ALIAS("spi:" DRVNAME);
177MODULE_ALIAS("platform:" DRVNAME);
178MODULE_ALIAS("spi:st7735r");
179MODULE_ALIAS("platform:st7735r");
180
181MODULE_DESCRIPTION("FB driver for the ST7735R LCD Controller");
182MODULE_AUTHOR("Noralf Tronnes");
183MODULE_LICENSE("GPL");
184