staging: fbtft: add support for ST7789V display controller

This patch adds support for the Sitronix ST7789V display controller.
The controller is intended for small color displays with a resolution
of up to 320x240 pixels.

Signed-off-by: Dennis Menschel <menschel-d@posteo.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Dennis Menschel 2015-10-07 22:15:45 +02:00 committed by Greg Kroah-Hartman
parent 56b3152e5e
commit d4c402ff35
3 changed files with 301 additions and 0 deletions

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@ -141,6 +141,16 @@ config FB_TFT_ST7735R
help
Generic Framebuffer support for ST7735R
config FB_TFT_ST7789V
tristate "FB driver for the ST7789V LCD Controller"
depends on FB_TFT
help
This enables generic framebuffer support for the Sitronix ST7789V
display controller. The controller is intended for small color
displays with a resolution of up to 320x240 pixels.
Say Y if you have such a display that utilizes this controller.
config FB_TFT_TINYLCD
tristate "FB driver for tinylcd.com display"
depends on FB_TFT

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@ -25,6 +25,7 @@ obj-$(CONFIG_FB_TFT_SSD1306) += fb_ssd1306.o
obj-$(CONFIG_FB_TFT_SSD1331) += fb_ssd1331.o
obj-$(CONFIG_FB_TFT_SSD1351) += fb_ssd1351.o
obj-$(CONFIG_FB_TFT_ST7735R) += fb_st7735r.o
obj-$(CONFIG_FB_TFT_ST7789V) += fb_st7789v.o
obj-$(CONFIG_FB_TFT_TINYLCD) += fb_tinylcd.o
obj-$(CONFIG_FB_TFT_TLS8204) += fb_tls8204.o
obj-$(CONFIG_FB_TFT_UC1611) += fb_uc1611.o

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@ -0,0 +1,290 @@
/*
* 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/init.h>
#include <linux/kernel.h>
#include <linux/module.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
*
* @SLPOUT: sleep out
* @DISPOFF: display off
* @DISPON: display on
* @CASET: column address set
* @RASET: row address set
* @RAMRW: memory write
* @MADCTL: memory data access control
* @COLMOD: interface pixel format
* @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.
*/
enum st7789v_command {
SLPOUT = 0x11,
DISPOFF = 0x28,
DISPON = 0x29,
CASET = 0x2A,
RASET = 0x2B,
RAMRW = 0x2C,
MADCTL = 0x36,
COLMOD = 0x3A,
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 */
/**
* default_init_sequence - default initialization sequence for ST7789V
*
* Most of the commands in this init sequence 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.
*/
static int default_init_sequence[] = {
/* turn off sleep mode */
-1, SLPOUT,
-2, 120,
/* set pixel format to RGB-565 */
-1, COLMOD, 0x05,
-1, PORCTRL, 0x08, 0x08, 0x00, 0x22, 0x22,
/*
* VGH = 13.26V
* VGL = -10.43V
*/
-1, GCTRL, 0x35,
/*
* VDV and VRH register values come from command write
* (instead of NVM)
*/
-1, VDVVRHEN, 0x01, 0xFF,
/*
* VAP = 4.1V + (VCOM + VCOM offset + 0.5 * VDV)
* VAN = -4.1V + (VCOM + VCOM offset + 0.5 * VDV)
*/
-1, VRHS, 0x0B,
/* VDV = 0V */
-1, VDVS, 0x20,
/* VCOM = 0.9V */
-1, VCOMS, 0x20,
/* VCOM offset = 0V */
-1, VCMOFSET, 0x20,
/*
* AVDD = 6.8V
* AVCL = -4.8V
* VDS = 2.3V
*/
-1, PWCTRL1, 0xA4, 0xA1,
-1, DISPON,
-3,
};
/**
* set_addr_win() - configure display area to use
*
* @par: FBTFT parameter object
* @xs: first active pixel of x-axis
* @ys: first active pixel of y-axis
* @xe: last active pixel of x-axis
* @ye: last active pixel of y-axis
*/
static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
{
write_reg(par, CASET, xs >> 8, xs & 0xFF, xe >> 8, xe & 0xFF);
write_reg(par, RASET, ys >> 8, ys & 0xFF, ye >> 8, ye & 0xFF);
write_reg(par, RAMRW);
}
/**
* 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, MADCTL, 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, DISPOFF);
else
write_reg(par, DISPON);
return 0;
}
static struct fbtft_display display = {
.regwidth = 8,
.width = 240,
.height = 320,
.init_sequence = default_init_sequence,
.gamma_num = 2,
.gamma_len = 14,
.gamma = DEFAULT_GAMMA,
.fbtftops = {
.set_addr_win = set_addr_win,
.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");