Commit 39c39072 authored by Thomas Petazzoni's avatar Thomas Petazzoni Committed by Greg Kroah-Hartman

staging: fbtft: add fb_pcd8544 driver

This commit adds the fb_pcd8544 driver from the fbtft project at
https://github.com/notro/fbtft.
Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: default avatarNoralf Tronnes <notro@tronnes.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 8d64b032
......@@ -73,3 +73,9 @@ config FB_TFT_ILI9486
depends on FB_TFT
help
Generic Framebuffer support for ILI9486
config FB_TFT_PCD8544
tristate "FB driver for the PCD8544 LCD Controller"
depends on FB_TFT
help
Generic Framebuffer support for PCD8544
......@@ -14,3 +14,4 @@ obj-$(CONFIG_FB_TFT_ILI9340) += fb_ili9340.o
obj-$(CONFIG_FB_TFT_ILI9341) += fb_ili9341.o
obj-$(CONFIG_FB_TFT_ILI9481) += fb_ili9481.o
obj-$(CONFIG_FB_TFT_ILI9486) += fb_ili9486.o
obj-$(CONFIG_FB_TFT_PCD8544) += fb_pcd8544.o
/*
* FB driver for the PCD8544 LCD Controller
*
* The display is monochrome and the video memory is RGB565.
* Any pixel value except 0 turns the pixel on.
*
* Copyright (C) 2013 Noralf Tronnes
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/gpio.h>
#include <linux/spi/spi.h>
#include <linux/delay.h>
#include "fbtft.h"
#define DRVNAME "fb_pcd8544"
#define WIDTH 84
#define HEIGHT 48
#define TXBUFLEN 84*6
#define DEFAULT_GAMMA "40" /* gamma is used to control contrast in this driver */
static unsigned tc = 0;
module_param(tc, uint, 0);
MODULE_PARM_DESC(tc, "TC[1:0] Temperature coefficient: 0-3 (default: 0)");
static unsigned bs = 4;
module_param(bs, uint, 0);
MODULE_PARM_DESC(bs, "BS[2:0] Bias voltage level: 0-7 (default: 4)");
static int init_display(struct fbtft_par *par)
{
fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
par->fbtftops.reset(par);
/* Function set */
write_reg(par, 0x21); /* 5:1 1
2:0 PD - Powerdown control: chip is active
1:0 V - Entry mode: horizontal addressing
0:1 H - Extended instruction set control: extended
*/
/* H=1 Temperature control */
write_reg(par, 0x04 | (tc & 0x3)); /*
2:1 1
1:x TC1 - Temperature Coefficient: 0x10
0:x TC0
*/
/* H=1 Bias system */
write_reg(par, 0x10 | (bs & 0x7)); /*
4:1 1
3:0 0
2:x BS2 - Bias System
1:x BS1
0:x BS0
*/
/* Function set */
write_reg(par, 0x22); /* 5:1 1
2:0 PD - Powerdown control: chip is active
1:1 V - Entry mode: vertical addressing
0:0 H - Extended instruction set control: basic
*/
/* H=0 Display control */
write_reg(par, 0x08 | 4); /*
3:1 1
2:1 D - DE: 10=normal mode
1:0 0
0:0 E
*/
return 0;
}
static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
{
fbtft_par_dbg(DEBUG_SET_ADDR_WIN, par, "%s(xs=%d, ys=%d, xe=%d, ye=%d)\n", __func__, xs, ys, xe, ye);
/* H=0 Set X address of RAM */
write_reg(par, 0x80); /* 7:1 1
6-0: X[6:0] - 0x00
*/
/* H=0 Set Y address of RAM */
write_reg(par, 0x40); /* 7:0 0
6:1 1
2-0: Y[2:0] - 0x0
*/
}
static int write_vmem(struct fbtft_par *par, size_t offset, size_t len)
{
u16 *vmem16 = (u16 *)par->info->screen_base;
u8 *buf = par->txbuf.buf;
int x, y, i;
int ret = 0;
fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s()\n", __func__);
for (x=0;x<84;x++) {
for (y=0;y<6;y++) {
*buf = 0x00;
for (i=0;i<8;i++) {
*buf |= (vmem16[(y*8+i)*84+x] ? 1 : 0) << i;
}
buf++;
}
}
/* Write data */
gpio_set_value(par->gpio.dc, 1);
ret = par->fbtftops.write(par, par->txbuf.buf, 6*84);
if (ret < 0)
dev_err(par->info->device, "%s: write failed and returned: %d\n", __func__, ret);
return ret;
}
static int set_gamma(struct fbtft_par *par, unsigned long *curves)
{
fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
/* apply mask */
curves[0] &= 0x7F;
write_reg(par, 0x23); /* turn on extended instruction set */
write_reg(par, 0x80 | curves[0]);
write_reg(par, 0x22); /* turn off extended instruction set */
return 0;
}
static struct fbtft_display display = {
.regwidth = 8,
.width = WIDTH,
.height = HEIGHT,
.txbuflen = TXBUFLEN,
.gamma_num = 1,
.gamma_len = 1,
.gamma = DEFAULT_GAMMA,
.fbtftops = {
.init_display = init_display,
.set_addr_win = set_addr_win,
.write_vmem = write_vmem,
.set_gamma = set_gamma,
},
.backlight = 1,
};
FBTFT_REGISTER_DRIVER(DRVNAME, "philips,pdc8544", &display);
MODULE_ALIAS("spi:" DRVNAME);
MODULE_ALIAS("spi:pdc8544");
MODULE_DESCRIPTION("FB driver for the PCD8544 LCD Controller");
MODULE_AUTHOR("Noralf Tronnes");
MODULE_LICENSE("GPL");
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