--- /dev/null
+/*
+ * FB driver for the TLS8204 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
+ * Copyright (C) 2014 Michael Hope (adapted for the TLS8204)
+ *
+ * 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_tls8204"
+#define WIDTH 84
+#define HEIGHT 48
+#define TXBUFLEN WIDTH
+#define DEFAULT_GAMMA "40" /* gamma is used to control contrast in this driver */
+
+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);
+
+ /* Enter extended command mode */
+ 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 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
+ */
+
+ /* Set the address of the first display line. */
+ write_reg(par, 0x04 | (64 >> 6));
+ write_reg(par, 0x40 | (64 & 0x3F));
+
+ /* Enter H=0 standard command mode */
+ write_reg(par, 0x20);
+
+ /* 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;
+ int x, y, i;
+ int ret = 0;
+
+ fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "%s()\n", __func__);
+
+ for (y = 0; y < HEIGHT/8; y++) {
+ u8 *buf = par->txbuf.buf;
+ /* The display is 102x68 but the LCD is 84x48. Set
+ the write pointer at the start of each row. */
+ gpio_set_value(par->gpio.dc, 0);
+ write_reg(par, 0x80 | 0);
+ write_reg(par, 0x40 | y);
+
+ for (x = 0; x < WIDTH; x++) {
+ u8 ch = 0;
+ for (i = 0; i < 8*WIDTH; i += WIDTH) {
+ ch >>= 1;
+ if (vmem16[(y*8*WIDTH)+i+x])
+ ch |= 0x80;
+ }
+ *buf++ = ch;
+ }
+ /* Write the row */
+ gpio_set_value(par->gpio.dc, 1);
+ ret = par->fbtftops.write(par, par->txbuf.buf, WIDTH);
+ if (ret < 0) {
+ dev_err(par->info->device,
+ "write failed and returned: %d\n", ret);
+ break;
+ }
+ }
+
+ 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, 0x21); /* turn on extended instruction set */
+ write_reg(par, 0x80 | curves[0]);
+ write_reg(par, 0x20); /* 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, "teralane,tls8204", &display);
+
+MODULE_ALIAS("spi:" DRVNAME);
+MODULE_ALIAS("spi:tls8204");
+
+MODULE_DESCRIPTION("FB driver for the TLS8204 LCD Controller");
+MODULE_AUTHOR("Michael Hope");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff