| /* |
| * FB driver for the ST7789V LCD Controller |
| * |
| * Copyright (C) 2015 Dennis Menschel |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| */ |
| |
| #include <linux/bitops.h> |
| #include <linux/delay.h> |
| #include <linux/init.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <video/mipi_display.h> |
| |
| #include "fbtft.h" |
| |
| #define DRVNAME "fb_st7789v" |
| |
| #define DEFAULT_GAMMA \ |
| "70 2C 2E 15 10 09 48 33 53 0B 19 18 20 25\n" \ |
| "70 2C 2E 15 10 09 48 33 53 0B 19 18 20 25" |
| |
| /** |
| * enum st7789v_command - ST7789V display controller commands |
| * |
| * @PORCTRL: porch setting |
| * @GCTRL: gate control |
| * @VCOMS: VCOM setting |
| * @VDVVRHEN: VDV and VRH command enable |
| * @VRHS: VRH set |
| * @VDVS: VDV set |
| * @VCMOFSET: VCOM offset set |
| * @PWCTRL1: power control 1 |
| * @PVGAMCTRL: positive voltage gamma control |
| * @NVGAMCTRL: negative voltage gamma control |
| * |
| * The command names are the same as those found in the datasheet to ease |
| * looking up their semantics and usage. |
| * |
| * Note that the ST7789V display controller offers quite a few more commands |
| * which have been omitted from this list as they are not used at the moment. |
| * Furthermore, commands that are compliant with the MIPI DCS have been left |
| * out as well to avoid duplicate entries. |
| */ |
| enum st7789v_command { |
| PORCTRL = 0xB2, |
| GCTRL = 0xB7, |
| VCOMS = 0xBB, |
| VDVVRHEN = 0xC2, |
| VRHS = 0xC3, |
| VDVS = 0xC4, |
| VCMOFSET = 0xC5, |
| PWCTRL1 = 0xD0, |
| PVGAMCTRL = 0xE0, |
| NVGAMCTRL = 0xE1, |
| }; |
| |
| #define MADCTL_BGR BIT(3) /* bitmask for RGB/BGR order */ |
| #define MADCTL_MV BIT(5) /* bitmask for page/column order */ |
| #define MADCTL_MX BIT(6) /* bitmask for column address order */ |
| #define MADCTL_MY BIT(7) /* bitmask for page address order */ |
| |
| /** |
| * init_display() - initialize the display controller |
| * |
| * @par: FBTFT parameter object |
| * |
| * Most of the commands in this init function set their parameters to the |
| * same default values which are already in place after the display has been |
| * powered up. (The main exception to this rule is the pixel format which |
| * would default to 18 instead of 16 bit per pixel.) |
| * Nonetheless, this sequence can be used as a template for concrete |
| * displays which usually need some adjustments. |
| * |
| * Return: 0 on success, < 0 if error occurred. |
| */ |
| static int init_display(struct fbtft_par *par) |
| { |
| /* turn off sleep mode */ |
| write_reg(par, MIPI_DCS_EXIT_SLEEP_MODE); |
| mdelay(120); |
| |
| /* set pixel format to RGB-565 */ |
| write_reg(par, MIPI_DCS_SET_PIXEL_FORMAT, MIPI_DCS_PIXEL_FMT_16BIT); |
| |
| write_reg(par, PORCTRL, 0x08, 0x08, 0x00, 0x22, 0x22); |
| |
| /* |
| * VGH = 13.26V |
| * VGL = -10.43V |
| */ |
| write_reg(par, GCTRL, 0x35); |
| |
| /* |
| * VDV and VRH register values come from command write |
| * (instead of NVM) |
| */ |
| write_reg(par, VDVVRHEN, 0x01, 0xFF); |
| |
| /* |
| * VAP = 4.1V + (VCOM + VCOM offset + 0.5 * VDV) |
| * VAN = -4.1V + (VCOM + VCOM offset + 0.5 * VDV) |
| */ |
| write_reg(par, VRHS, 0x0B); |
| |
| /* VDV = 0V */ |
| write_reg(par, VDVS, 0x20); |
| |
| /* VCOM = 0.9V */ |
| write_reg(par, VCOMS, 0x20); |
| |
| /* VCOM offset = 0V */ |
| write_reg(par, VCMOFSET, 0x20); |
| |
| /* |
| * AVDD = 6.8V |
| * AVCL = -4.8V |
| * VDS = 2.3V |
| */ |
| write_reg(par, PWCTRL1, 0xA4, 0xA1); |
| |
| write_reg(par, MIPI_DCS_SET_DISPLAY_ON); |
| return 0; |
| } |
| |
| /** |
| * set_var() - apply LCD properties like rotation and BGR mode |
| * |
| * @par: FBTFT parameter object |
| * |
| * Return: 0 on success, < 0 if error occurred. |
| */ |
| static int set_var(struct fbtft_par *par) |
| { |
| u8 madctl_par = 0; |
| |
| if (par->bgr) |
| madctl_par |= MADCTL_BGR; |
| switch (par->info->var.rotate) { |
| case 0: |
| break; |
| case 90: |
| madctl_par |= (MADCTL_MV | MADCTL_MY); |
| break; |
| case 180: |
| madctl_par |= (MADCTL_MX | MADCTL_MY); |
| break; |
| case 270: |
| madctl_par |= (MADCTL_MV | MADCTL_MX); |
| break; |
| default: |
| return -EINVAL; |
| } |
| write_reg(par, MIPI_DCS_SET_ADDRESS_MODE, madctl_par); |
| return 0; |
| } |
| |
| /** |
| * set_gamma() - set gamma curves |
| * |
| * @par: FBTFT parameter object |
| * @curves: gamma curves |
| * |
| * Before the gamma curves are applied, they are preprocessed with a bitmask |
| * to ensure syntactically correct input for the display controller. |
| * This implies that the curves input parameter might be changed by this |
| * function and that illegal gamma values are auto-corrected and not |
| * reported as errors. |
| * |
| * Return: 0 on success, < 0 if error occurred. |
| */ |
| static int set_gamma(struct fbtft_par *par, unsigned long *curves) |
| { |
| int i; |
| int j; |
| int c; /* curve index offset */ |
| |
| /* |
| * Bitmasks for gamma curve command parameters. |
| * The masks are the same for both positive and negative voltage |
| * gamma curves. |
| */ |
| const u8 gamma_par_mask[] = { |
| 0xFF, /* V63[3:0], V0[3:0]*/ |
| 0x3F, /* V1[5:0] */ |
| 0x3F, /* V2[5:0] */ |
| 0x1F, /* V4[4:0] */ |
| 0x1F, /* V6[4:0] */ |
| 0x3F, /* J0[1:0], V13[3:0] */ |
| 0x7F, /* V20[6:0] */ |
| 0x77, /* V36[2:0], V27[2:0] */ |
| 0x7F, /* V43[6:0] */ |
| 0x3F, /* J1[1:0], V50[3:0] */ |
| 0x1F, /* V57[4:0] */ |
| 0x1F, /* V59[4:0] */ |
| 0x3F, /* V61[5:0] */ |
| 0x3F, /* V62[5:0] */ |
| }; |
| |
| for (i = 0; i < par->gamma.num_curves; i++) { |
| c = i * par->gamma.num_values; |
| for (j = 0; j < par->gamma.num_values; j++) |
| curves[c + j] &= gamma_par_mask[j]; |
| write_reg( |
| par, PVGAMCTRL + i, |
| curves[c + 0], curves[c + 1], curves[c + 2], |
| curves[c + 3], curves[c + 4], curves[c + 5], |
| curves[c + 6], curves[c + 7], curves[c + 8], |
| curves[c + 9], curves[c + 10], curves[c + 11], |
| curves[c + 12], curves[c + 13]); |
| } |
| return 0; |
| } |
| |
| /** |
| * blank() - blank the display |
| * |
| * @par: FBTFT parameter object |
| * @on: whether to enable or disable blanking the display |
| * |
| * Return: 0 on success, < 0 if error occurred. |
| */ |
| static int blank(struct fbtft_par *par, bool on) |
| { |
| if (on) |
| write_reg(par, MIPI_DCS_SET_DISPLAY_OFF); |
| else |
| write_reg(par, MIPI_DCS_SET_DISPLAY_ON); |
| return 0; |
| } |
| |
| static struct fbtft_display display = { |
| .regwidth = 8, |
| .width = 240, |
| .height = 320, |
| .gamma_num = 2, |
| .gamma_len = 14, |
| .gamma = DEFAULT_GAMMA, |
| .fbtftops = { |
| .init_display = init_display, |
| .set_var = set_var, |
| .set_gamma = set_gamma, |
| .blank = blank, |
| }, |
| }; |
| |
| FBTFT_REGISTER_DRIVER(DRVNAME, "sitronix,st7789v", &display); |
| |
| MODULE_ALIAS("spi:" DRVNAME); |
| MODULE_ALIAS("platform:" DRVNAME); |
| MODULE_ALIAS("spi:st7789v"); |
| MODULE_ALIAS("platform:st7789v"); |
| |
| MODULE_DESCRIPTION("FB driver for the ST7789V LCD Controller"); |
| MODULE_AUTHOR("Dennis Menschel"); |
| MODULE_LICENSE("GPL"); |