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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/staging/fbtft/fb_pcd8544.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/staging/fbtft/fb_pcd8544.c')
-rw-r--r-- | drivers/staging/fbtft/fb_pcd8544.c | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/drivers/staging/fbtft/fb_pcd8544.c b/drivers/staging/fbtft/fb_pcd8544.c new file mode 100644 index 000000000..08f8a4bb8 --- /dev/null +++ b/drivers/staging/fbtft/fb_pcd8544.c @@ -0,0 +1,167 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * 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 + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/gpio/consumer.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 controls the contrast in this driver */ + +static unsigned int tc; +module_param(tc, uint, 0000); +MODULE_PARM_DESC(tc, "TC[1:0] Temperature coefficient: 0-3 (default: 0)"); + +static unsigned int bs = 4; +module_param(bs, uint, 0000); +MODULE_PARM_DESC(bs, "BS[2:0] Bias voltage level: 0-7 (default: 4)"); + +static int init_display(struct fbtft_par *par) +{ + par->fbtftops.reset(par); + + /* Function set + * + * 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 + */ + write_reg(par, 0x21); + + /* H=1 Temperature control + * + * 2:1 1 + * 1:x TC1 - Temperature Coefficient: 0x10 + * 0:x TC0 + */ + write_reg(par, 0x04 | (tc & 0x3)); + + /* H=1 Bias system + * + * 4:1 1 + * 3:0 0 + * 2:x BS2 - Bias System + * 1:x BS1 + * 0:x BS0 + */ + write_reg(par, 0x10 | (bs & 0x7)); + + /* Function set + * + * 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 + */ + write_reg(par, 0x22); + + /* H=0 Display control + * + * 3:1 1 + * 2:1 D - DE: 10=normal mode + * 1:0 0 + * 0:0 E + */ + write_reg(par, 0x08 | 4); + + return 0; +} + +static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye) +{ + /* H=0 Set X address of RAM + * + * 7:1 1 + * 6-0: X[6:0] - 0x00 + */ + write_reg(par, 0x80); + + /* H=0 Set Y address of RAM + * + * 7:0 0 + * 6:1 1 + * 2-0: Y[2:0] - 0x0 + */ + write_reg(par, 0x40); +} + +static int write_vmem(struct fbtft_par *par, size_t offset, size_t len) +{ + u16 *vmem16 = (u16 *)par->info->screen_buffer; + u8 *buf = par->txbuf.buf; + int x, y, i; + int ret = 0; + + 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 */ + gpiod_set_value(par->gpio.dc, 1); + ret = par->fbtftops.write(par, par->txbuf.buf, 6 * 84); + if (ret < 0) + dev_err(par->info->device, "write failed and returned: %d\n", + ret); + + return ret; +} + +static int set_gamma(struct fbtft_par *par, u32 *curves) +{ + /* 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,pcd8544", &display); + +MODULE_ALIAS("spi:" DRVNAME); +MODULE_ALIAS("spi:pcd8544"); + +MODULE_DESCRIPTION("FB driver for the PCD8544 LCD Controller"); +MODULE_AUTHOR("Noralf Tronnes"); +MODULE_LICENSE("GPL"); |