drivers/staging/fbtft/fb_st7789v.c - arm/linux - Git at Google

 /*
  * 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, u32 *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.
 	 */
 	static 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");
	/*
	* 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, u32 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.
	*/
	static 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");