1 // SPDX-License-Identifier: GPL-2.0+
3 * FB driver for the ILI9320 LCD Controller
5 * Copyright (C) 2013 Noralf Tronnes
8 #include <linux/module.h>
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/gpio.h>
12 #include <linux/spi/spi.h>
13 #include <linux/delay.h>
17 #define DRVNAME "fb_ili9320"
20 #define DEFAULT_GAMMA "07 07 6 0 0 0 5 5 4 0\n" \
21 "07 08 4 7 5 1 2 0 7 7"
23 static unsigned int read_devicecode(struct fbtft_par *par)
28 write_reg(par, 0x0000);
29 ret = par->fbtftops.read(par, rxbuf, 4);
30 return (rxbuf[2] << 8) | rxbuf[3];
33 static int init_display(struct fbtft_par *par)
37 par->fbtftops.reset(par);
39 devcode = read_devicecode(par);
40 fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "Device code: 0x%04X\n",
42 if ((devcode != 0x0000) && (devcode != 0x9320))
43 dev_warn(par->info->device,
44 "Unrecognized Device code: 0x%04X (expected 0x9320)\n",
47 /* Initialization sequence from ILI9320 Application Notes */
49 /* *********** Start Initial Sequence ********* */
50 /* Set the Vcore voltage and this setting is must. */
51 write_reg(par, 0x00E5, 0x8000);
53 /* Start internal OSC. */
54 write_reg(par, 0x0000, 0x0001);
56 /* set SS and SM bit */
57 write_reg(par, 0x0001, 0x0100);
59 /* set 1 line inversion */
60 write_reg(par, 0x0002, 0x0700);
63 write_reg(par, 0x0004, 0x0000);
65 /* set the back and front porch */
66 write_reg(par, 0x0008, 0x0202);
68 /* set non-display area refresh cycle */
69 write_reg(par, 0x0009, 0x0000);
72 write_reg(par, 0x000A, 0x0000);
74 /* RGB interface setting */
75 write_reg(par, 0x000C, 0x0000);
77 /* Frame marker Position */
78 write_reg(par, 0x000D, 0x0000);
80 /* RGB interface polarity */
81 write_reg(par, 0x000F, 0x0000);
83 /* ***********Power On sequence *************** */
84 /* SAP, BT[3:0], AP, DSTB, SLP, STB */
85 write_reg(par, 0x0010, 0x0000);
87 /* DC1[2:0], DC0[2:0], VC[2:0] */
88 write_reg(par, 0x0011, 0x0007);
90 /* VREG1OUT voltage */
91 write_reg(par, 0x0012, 0x0000);
93 /* VDV[4:0] for VCOM amplitude */
94 write_reg(par, 0x0013, 0x0000);
96 /* Dis-charge capacitor power voltage */
99 /* SAP, BT[3:0], AP, DSTB, SLP, STB */
100 write_reg(par, 0x0010, 0x17B0);
102 /* R11h=0x0031 at VCI=3.3V DC1[2:0], DC0[2:0], VC[2:0] */
103 write_reg(par, 0x0011, 0x0031);
106 /* R12h=0x0138 at VCI=3.3V VREG1OUT voltage */
107 write_reg(par, 0x0012, 0x0138);
110 /* R13h=0x1800 at VCI=3.3V VDV[4:0] for VCOM amplitude */
111 write_reg(par, 0x0013, 0x1800);
113 /* R29h=0x0008 at VCI=3.3V VCM[4:0] for VCOMH */
114 write_reg(par, 0x0029, 0x0008);
117 /* GRAM horizontal Address */
118 write_reg(par, 0x0020, 0x0000);
120 /* GRAM Vertical Address */
121 write_reg(par, 0x0021, 0x0000);
123 /* ------------------ Set GRAM area --------------- */
124 /* Horizontal GRAM Start Address */
125 write_reg(par, 0x0050, 0x0000);
127 /* Horizontal GRAM End Address */
128 write_reg(par, 0x0051, 0x00EF);
130 /* Vertical GRAM Start Address */
131 write_reg(par, 0x0052, 0x0000);
133 /* Vertical GRAM End Address */
134 write_reg(par, 0x0053, 0x013F);
137 write_reg(par, 0x0060, 0x2700);
140 write_reg(par, 0x0061, 0x0001);
142 /* set scrolling line */
143 write_reg(par, 0x006A, 0x0000);
145 /* -------------- Partial Display Control --------- */
146 write_reg(par, 0x0080, 0x0000);
147 write_reg(par, 0x0081, 0x0000);
148 write_reg(par, 0x0082, 0x0000);
149 write_reg(par, 0x0083, 0x0000);
150 write_reg(par, 0x0084, 0x0000);
151 write_reg(par, 0x0085, 0x0000);
153 /* -------------- Panel Control ------------------- */
154 write_reg(par, 0x0090, 0x0010);
155 write_reg(par, 0x0092, 0x0000);
156 write_reg(par, 0x0093, 0x0003);
157 write_reg(par, 0x0095, 0x0110);
158 write_reg(par, 0x0097, 0x0000);
159 write_reg(par, 0x0098, 0x0000);
160 write_reg(par, 0x0007, 0x0173); /* 262K color and display ON */
165 static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
167 switch (par->info->var.rotate) {
168 /* R20h = Horizontal GRAM Start Address */
169 /* R21h = Vertical GRAM Start Address */
171 write_reg(par, 0x0020, xs);
172 write_reg(par, 0x0021, ys);
175 write_reg(par, 0x0020, WIDTH - 1 - xs);
176 write_reg(par, 0x0021, HEIGHT - 1 - ys);
179 write_reg(par, 0x0020, WIDTH - 1 - ys);
180 write_reg(par, 0x0021, xs);
183 write_reg(par, 0x0020, ys);
184 write_reg(par, 0x0021, HEIGHT - 1 - xs);
187 write_reg(par, 0x0022); /* Write Data to GRAM */
190 static int set_var(struct fbtft_par *par)
192 switch (par->info->var.rotate) {
194 write_reg(par, 0x3, (par->bgr << 12) | 0x30);
197 write_reg(par, 0x3, (par->bgr << 12) | 0x28);
200 write_reg(par, 0x3, (par->bgr << 12) | 0x00);
203 write_reg(par, 0x3, (par->bgr << 12) | 0x18);
210 * Gamma string format:
211 * VRP0 VRP1 RP0 RP1 KP0 KP1 KP2 KP3 KP4 KP5
212 * VRN0 VRN1 RN0 RN1 KN0 KN1 KN2 KN3 KN4 KN5
214 #define CURVE(num, idx) curves[num * par->gamma.num_values + idx]
215 static int set_gamma(struct fbtft_par *par, u32 *curves)
217 unsigned long mask[] = {
218 0x1f, 0x1f, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
219 0x1f, 0x1f, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
224 for (i = 0; i < 2; i++)
225 for (j = 0; j < 10; j++)
226 CURVE(i, j) &= mask[i * par->gamma.num_values + j];
228 write_reg(par, 0x0030, CURVE(0, 5) << 8 | CURVE(0, 4));
229 write_reg(par, 0x0031, CURVE(0, 7) << 8 | CURVE(0, 6));
230 write_reg(par, 0x0032, CURVE(0, 9) << 8 | CURVE(0, 8));
231 write_reg(par, 0x0035, CURVE(0, 3) << 8 | CURVE(0, 2));
232 write_reg(par, 0x0036, CURVE(0, 1) << 8 | CURVE(0, 0));
234 write_reg(par, 0x0037, CURVE(1, 5) << 8 | CURVE(1, 4));
235 write_reg(par, 0x0038, CURVE(1, 7) << 8 | CURVE(1, 6));
236 write_reg(par, 0x0039, CURVE(1, 9) << 8 | CURVE(1, 8));
237 write_reg(par, 0x003C, CURVE(1, 3) << 8 | CURVE(1, 2));
238 write_reg(par, 0x003D, CURVE(1, 1) << 8 | CURVE(1, 0));
245 static struct fbtft_display display = {
251 .gamma = DEFAULT_GAMMA,
253 .init_display = init_display,
254 .set_addr_win = set_addr_win,
256 .set_gamma = set_gamma,
260 FBTFT_REGISTER_DRIVER(DRVNAME, "ilitek,ili9320", &display);
262 MODULE_ALIAS("spi:" DRVNAME);
263 MODULE_ALIAS("platform:" DRVNAME);
264 MODULE_ALIAS("spi:ili9320");
265 MODULE_ALIAS("platform:ili9320");
267 MODULE_DESCRIPTION("FB driver for the ILI9320 LCD Controller");
268 MODULE_AUTHOR("Noralf Tronnes");
269 MODULE_LICENSE("GPL");