Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 1 | /* |
| 2 | * FB driver for the ST7789V LCD Controller |
| 3 | * |
| 4 | * Copyright (C) 2015 Dennis Menschel |
| 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/bitops.h> |
Dennis Menschel | ef8f317 | 2015-10-21 23:16:55 +0200 | [diff] [blame] | 18 | #include <linux/delay.h> |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 19 | #include <linux/init.h> |
| 20 | #include <linux/kernel.h> |
| 21 | #include <linux/module.h> |
Dennis Menschel | 598af18 | 2015-10-21 23:16:53 +0200 | [diff] [blame] | 22 | #include <video/mipi_display.h> |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 23 | |
| 24 | #include "fbtft.h" |
| 25 | |
| 26 | #define DRVNAME "fb_st7789v" |
| 27 | |
| 28 | #define DEFAULT_GAMMA \ |
| 29 | "70 2C 2E 15 10 09 48 33 53 0B 19 18 20 25\n" \ |
| 30 | "70 2C 2E 15 10 09 48 33 53 0B 19 18 20 25" |
| 31 | |
| 32 | /** |
| 33 | * enum st7789v_command - ST7789V display controller commands |
| 34 | * |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 35 | * @PORCTRL: porch setting |
| 36 | * @GCTRL: gate control |
| 37 | * @VCOMS: VCOM setting |
| 38 | * @VDVVRHEN: VDV and VRH command enable |
| 39 | * @VRHS: VRH set |
| 40 | * @VDVS: VDV set |
| 41 | * @VCMOFSET: VCOM offset set |
| 42 | * @PWCTRL1: power control 1 |
| 43 | * @PVGAMCTRL: positive voltage gamma control |
| 44 | * @NVGAMCTRL: negative voltage gamma control |
| 45 | * |
| 46 | * The command names are the same as those found in the datasheet to ease |
| 47 | * looking up their semantics and usage. |
| 48 | * |
| 49 | * Note that the ST7789V display controller offers quite a few more commands |
| 50 | * which have been omitted from this list as they are not used at the moment. |
Dennis Menschel | 598af18 | 2015-10-21 23:16:53 +0200 | [diff] [blame] | 51 | * Furthermore, commands that are compliant with the MIPI DCS have been left |
| 52 | * out as well to avoid duplicate entries. |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 53 | */ |
| 54 | enum st7789v_command { |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 55 | PORCTRL = 0xB2, |
| 56 | GCTRL = 0xB7, |
| 57 | VCOMS = 0xBB, |
| 58 | VDVVRHEN = 0xC2, |
| 59 | VRHS = 0xC3, |
| 60 | VDVS = 0xC4, |
| 61 | VCMOFSET = 0xC5, |
| 62 | PWCTRL1 = 0xD0, |
| 63 | PVGAMCTRL = 0xE0, |
| 64 | NVGAMCTRL = 0xE1, |
| 65 | }; |
| 66 | |
| 67 | #define MADCTL_BGR BIT(3) /* bitmask for RGB/BGR order */ |
| 68 | #define MADCTL_MV BIT(5) /* bitmask for page/column order */ |
| 69 | #define MADCTL_MX BIT(6) /* bitmask for column address order */ |
| 70 | #define MADCTL_MY BIT(7) /* bitmask for page address order */ |
| 71 | |
| 72 | /** |
Dennis Menschel | ef8f317 | 2015-10-21 23:16:55 +0200 | [diff] [blame] | 73 | * init_display() - initialize the display controller |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 74 | * |
Dennis Menschel | ef8f317 | 2015-10-21 23:16:55 +0200 | [diff] [blame] | 75 | * @par: FBTFT parameter object |
| 76 | * |
| 77 | * Most of the commands in this init function set their parameters to the |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 78 | * same default values which are already in place after the display has been |
| 79 | * powered up. (The main exception to this rule is the pixel format which |
| 80 | * would default to 18 instead of 16 bit per pixel.) |
| 81 | * Nonetheless, this sequence can be used as a template for concrete |
| 82 | * displays which usually need some adjustments. |
Dennis Menschel | ef8f317 | 2015-10-21 23:16:55 +0200 | [diff] [blame] | 83 | * |
| 84 | * Return: 0 on success, < 0 if error occurred. |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 85 | */ |
Dennis Menschel | ef8f317 | 2015-10-21 23:16:55 +0200 | [diff] [blame] | 86 | static int init_display(struct fbtft_par *par) |
| 87 | { |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 88 | /* turn off sleep mode */ |
Dennis Menschel | ef8f317 | 2015-10-21 23:16:55 +0200 | [diff] [blame] | 89 | write_reg(par, MIPI_DCS_EXIT_SLEEP_MODE); |
| 90 | mdelay(120); |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 91 | |
| 92 | /* set pixel format to RGB-565 */ |
Dennis Menschel | ef8f317 | 2015-10-21 23:16:55 +0200 | [diff] [blame] | 93 | write_reg(par, MIPI_DCS_SET_PIXEL_FORMAT, MIPI_DCS_PIXEL_FMT_16BIT); |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 94 | |
Dennis Menschel | ef8f317 | 2015-10-21 23:16:55 +0200 | [diff] [blame] | 95 | write_reg(par, PORCTRL, 0x08, 0x08, 0x00, 0x22, 0x22); |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 96 | |
| 97 | /* |
| 98 | * VGH = 13.26V |
| 99 | * VGL = -10.43V |
| 100 | */ |
Dennis Menschel | ef8f317 | 2015-10-21 23:16:55 +0200 | [diff] [blame] | 101 | write_reg(par, GCTRL, 0x35); |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 102 | |
| 103 | /* |
| 104 | * VDV and VRH register values come from command write |
| 105 | * (instead of NVM) |
| 106 | */ |
Dennis Menschel | ef8f317 | 2015-10-21 23:16:55 +0200 | [diff] [blame] | 107 | write_reg(par, VDVVRHEN, 0x01, 0xFF); |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 108 | |
| 109 | /* |
| 110 | * VAP = 4.1V + (VCOM + VCOM offset + 0.5 * VDV) |
| 111 | * VAN = -4.1V + (VCOM + VCOM offset + 0.5 * VDV) |
| 112 | */ |
Dennis Menschel | ef8f317 | 2015-10-21 23:16:55 +0200 | [diff] [blame] | 113 | write_reg(par, VRHS, 0x0B); |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 114 | |
| 115 | /* VDV = 0V */ |
Dennis Menschel | ef8f317 | 2015-10-21 23:16:55 +0200 | [diff] [blame] | 116 | write_reg(par, VDVS, 0x20); |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 117 | |
| 118 | /* VCOM = 0.9V */ |
Dennis Menschel | ef8f317 | 2015-10-21 23:16:55 +0200 | [diff] [blame] | 119 | write_reg(par, VCOMS, 0x20); |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 120 | |
| 121 | /* VCOM offset = 0V */ |
Dennis Menschel | ef8f317 | 2015-10-21 23:16:55 +0200 | [diff] [blame] | 122 | write_reg(par, VCMOFSET, 0x20); |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 123 | |
| 124 | /* |
| 125 | * AVDD = 6.8V |
| 126 | * AVCL = -4.8V |
| 127 | * VDS = 2.3V |
| 128 | */ |
Dennis Menschel | ef8f317 | 2015-10-21 23:16:55 +0200 | [diff] [blame] | 129 | write_reg(par, PWCTRL1, 0xA4, 0xA1); |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 130 | |
Dennis Menschel | ef8f317 | 2015-10-21 23:16:55 +0200 | [diff] [blame] | 131 | write_reg(par, MIPI_DCS_SET_DISPLAY_ON); |
| 132 | return 0; |
| 133 | } |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 134 | |
| 135 | /** |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 136 | * set_var() - apply LCD properties like rotation and BGR mode |
| 137 | * |
| 138 | * @par: FBTFT parameter object |
| 139 | * |
| 140 | * Return: 0 on success, < 0 if error occurred. |
| 141 | */ |
| 142 | static int set_var(struct fbtft_par *par) |
| 143 | { |
| 144 | u8 madctl_par = 0; |
| 145 | |
| 146 | if (par->bgr) |
| 147 | madctl_par |= MADCTL_BGR; |
| 148 | switch (par->info->var.rotate) { |
| 149 | case 0: |
| 150 | break; |
| 151 | case 90: |
| 152 | madctl_par |= (MADCTL_MV | MADCTL_MY); |
| 153 | break; |
| 154 | case 180: |
| 155 | madctl_par |= (MADCTL_MX | MADCTL_MY); |
| 156 | break; |
| 157 | case 270: |
| 158 | madctl_par |= (MADCTL_MV | MADCTL_MX); |
| 159 | break; |
| 160 | default: |
| 161 | return -EINVAL; |
| 162 | } |
Dennis Menschel | 598af18 | 2015-10-21 23:16:53 +0200 | [diff] [blame] | 163 | write_reg(par, MIPI_DCS_SET_ADDRESS_MODE, madctl_par); |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 164 | return 0; |
| 165 | } |
| 166 | |
| 167 | /** |
| 168 | * set_gamma() - set gamma curves |
| 169 | * |
| 170 | * @par: FBTFT parameter object |
| 171 | * @curves: gamma curves |
| 172 | * |
| 173 | * Before the gamma curves are applied, they are preprocessed with a bitmask |
| 174 | * to ensure syntactically correct input for the display controller. |
| 175 | * This implies that the curves input parameter might be changed by this |
| 176 | * function and that illegal gamma values are auto-corrected and not |
| 177 | * reported as errors. |
| 178 | * |
| 179 | * Return: 0 on success, < 0 if error occurred. |
| 180 | */ |
| 181 | static int set_gamma(struct fbtft_par *par, unsigned long *curves) |
| 182 | { |
| 183 | int i; |
| 184 | int j; |
| 185 | int c; /* curve index offset */ |
| 186 | |
| 187 | /* |
| 188 | * Bitmasks for gamma curve command parameters. |
| 189 | * The masks are the same for both positive and negative voltage |
| 190 | * gamma curves. |
| 191 | */ |
| 192 | const u8 gamma_par_mask[] = { |
| 193 | 0xFF, /* V63[3:0], V0[3:0]*/ |
| 194 | 0x3F, /* V1[5:0] */ |
| 195 | 0x3F, /* V2[5:0] */ |
| 196 | 0x1F, /* V4[4:0] */ |
| 197 | 0x1F, /* V6[4:0] */ |
| 198 | 0x3F, /* J0[1:0], V13[3:0] */ |
| 199 | 0x7F, /* V20[6:0] */ |
| 200 | 0x77, /* V36[2:0], V27[2:0] */ |
| 201 | 0x7F, /* V43[6:0] */ |
| 202 | 0x3F, /* J1[1:0], V50[3:0] */ |
| 203 | 0x1F, /* V57[4:0] */ |
| 204 | 0x1F, /* V59[4:0] */ |
| 205 | 0x3F, /* V61[5:0] */ |
| 206 | 0x3F, /* V62[5:0] */ |
| 207 | }; |
| 208 | |
| 209 | for (i = 0; i < par->gamma.num_curves; i++) { |
| 210 | c = i * par->gamma.num_values; |
| 211 | for (j = 0; j < par->gamma.num_values; j++) |
| 212 | curves[c + j] &= gamma_par_mask[j]; |
| 213 | write_reg( |
| 214 | par, PVGAMCTRL + i, |
| 215 | curves[c + 0], curves[c + 1], curves[c + 2], |
| 216 | curves[c + 3], curves[c + 4], curves[c + 5], |
| 217 | curves[c + 6], curves[c + 7], curves[c + 8], |
| 218 | curves[c + 9], curves[c + 10], curves[c + 11], |
| 219 | curves[c + 12], curves[c + 13]); |
| 220 | } |
| 221 | return 0; |
| 222 | } |
| 223 | |
| 224 | /** |
| 225 | * blank() - blank the display |
| 226 | * |
| 227 | * @par: FBTFT parameter object |
| 228 | * @on: whether to enable or disable blanking the display |
| 229 | * |
| 230 | * Return: 0 on success, < 0 if error occurred. |
| 231 | */ |
| 232 | static int blank(struct fbtft_par *par, bool on) |
| 233 | { |
| 234 | if (on) |
Dennis Menschel | 598af18 | 2015-10-21 23:16:53 +0200 | [diff] [blame] | 235 | write_reg(par, MIPI_DCS_SET_DISPLAY_OFF); |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 236 | else |
Dennis Menschel | 598af18 | 2015-10-21 23:16:53 +0200 | [diff] [blame] | 237 | write_reg(par, MIPI_DCS_SET_DISPLAY_ON); |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 238 | return 0; |
| 239 | } |
| 240 | |
| 241 | static struct fbtft_display display = { |
| 242 | .regwidth = 8, |
| 243 | .width = 240, |
| 244 | .height = 320, |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 245 | .gamma_num = 2, |
| 246 | .gamma_len = 14, |
| 247 | .gamma = DEFAULT_GAMMA, |
| 248 | .fbtftops = { |
Dennis Menschel | ef8f317 | 2015-10-21 23:16:55 +0200 | [diff] [blame] | 249 | .init_display = init_display, |
Dennis Menschel | d4c402f | 2015-10-07 22:15:45 +0200 | [diff] [blame] | 250 | .set_var = set_var, |
| 251 | .set_gamma = set_gamma, |
| 252 | .blank = blank, |
| 253 | }, |
| 254 | }; |
| 255 | |
| 256 | FBTFT_REGISTER_DRIVER(DRVNAME, "sitronix,st7789v", &display); |
| 257 | |
| 258 | MODULE_ALIAS("spi:" DRVNAME); |
| 259 | MODULE_ALIAS("platform:" DRVNAME); |
| 260 | MODULE_ALIAS("spi:st7789v"); |
| 261 | MODULE_ALIAS("platform:st7789v"); |
| 262 | |
| 263 | MODULE_DESCRIPTION("FB driver for the ST7789V LCD Controller"); |
| 264 | MODULE_AUTHOR("Dennis Menschel"); |
| 265 | MODULE_LICENSE("GPL"); |