--- /dev/null
+/*
+ * FB driver for the UltraChip UC1611 LCD controller
+ *
+ * The display is 4-bit grayscale (16 shades) 240x160.
+ *
+ * Copyright (C) 2015 Henri Chain
+ *
+ * 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/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_uc1611"
+#define WIDTH 240
+#define HEIGHT 160
+#define BPP 8
+#define FPS 40
+
+/*
+ * LCD voltage is a combination of ratio, gain, pot and temp
+ *
+ * V_LCD = V_BIAS * ratio
+ * V_LCD = (C_V0 + C_PM × pot) * (1 + (T - 25) * temp)
+ * C_V0 and C_PM depend on ratio and gain
+ * T is ambient temperature
+ */
+
+/* BR -> actual ratio: 0-3 -> 5, 10, 11, 13 */
+static unsigned ratio = 2;
+module_param(ratio, uint, 0);
+MODULE_PARM_DESC(ratio, "BR[1:0] Bias voltage ratio: 0-3 (default: 2)");
+
+static unsigned gain = 3;
+module_param(gain, uint, 0);
+MODULE_PARM_DESC(gain, "GN[1:0] Bias voltage gain: 0-3 (default: 3)");
+
+static unsigned pot = 16;
+module_param(pot, uint, 0);
+MODULE_PARM_DESC(pot, "PM[6:0] Bias voltage pot.: 0-63 (default: 16)");
+
+/* TC -> % compensation per deg C: 0-3 -> -.05, -.10, -.015, -.20 */
+static unsigned temp;
+module_param(temp, uint, 0);
+MODULE_PARM_DESC(temp, "TC[1:0] Temperature compensation: 0-3 (default: 0)");
+
+/* PC[1:0] -> LCD capacitance: 0-3 -> <20nF, 20-28 nF, 29-40 nF, 40-56 nF */
+static unsigned load = 1;
+module_param(load, uint, 0);
+MODULE_PARM_DESC(load, "PC[1:0] Panel Loading: 0-3 (default: 1)");
+
+/* PC[3:2] -> V_LCD: 0, 1, 3 -> ext., int. with ratio = 5, int. standard */
+static unsigned pump = 3;
+module_param(pump, uint, 0);
+MODULE_PARM_DESC(pump, "PC[3:2] Pump control: 0,1,3 (default: 3)");
+
+static int init_display(struct fbtft_par *par)
+{
+ int ret;
+
+ /* Set CS active high */
+ par->spi->mode |= SPI_CS_HIGH;
+ ret = spi_setup(par->spi);
+ if (ret) {
+ dev_err(par->info->device, "Could not set SPI_CS_HIGH\n");
+ return ret;
+ }
+
+ /* Reset controller */
+ write_reg(par, 0xE2);
+
+ /* Set bias ratio */
+ write_reg(par, 0xE8 | (ratio & 0x03));
+
+ /* Set bias gain and potentiometer */
+ write_reg(par, 0x81);
+ write_reg(par, (gain & 0x03) << 6 | (pot & 0x3F));
+
+ /* Set temperature compensation */
+ write_reg(par, 0x24 | (temp & 0x03));
+
+ /* Set panel loading */
+ write_reg(par, 0x28 | (load & 0x03));
+
+ /* Set pump control */
+ write_reg(par, 0x2C | (pump & 0x03));
+
+ /* Set inverse display */
+ write_reg(par, 0xA6 | (0x01 & 0x01));
+
+ /* Set 4-bit grayscale mode */
+ write_reg(par, 0xD0 | (0x02 & 0x03));
+
+ /* Set Display enable */
+ write_reg(par, 0xA8 | 0x07);
+
+ return 0;
+}
+
+static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
+{
+ switch (par->info->var.rotate) {
+ case 90:
+ case 270:
+ /* Set column address */
+ write_reg(par, ys & 0x0F);
+ write_reg(par, 0x10 | (ys >> 4));
+
+ /* Set page address (divide xs by 2) (not used by driver) */
+ write_reg(par, 0x60 | ((xs >> 1) & 0x0F));
+ write_reg(par, 0x70 | (xs >> 5));
+ break;
+ default:
+ /* Set column address (not used by driver) */
+ write_reg(par, xs & 0x0F);
+ write_reg(par, 0x10 | (xs >> 4));
+
+ /* Set page address (divide ys by 2) */
+ write_reg(par, 0x60 | ((ys >> 1) & 0x0F));
+ write_reg(par, 0x70 | (ys >> 5));
+ break;
+ }
+}
+
+static int blank(struct fbtft_par *par, bool on)
+{
+ fbtft_par_dbg(DEBUG_BLANK, par, "%s(blank=%s)\n",
+ __func__, on ? "true" : "false");
+
+ if (on)
+ write_reg(par, 0xA8 | 0x00);
+ else
+ write_reg(par, 0xA8 | 0x07);
+ return 0;
+}
+
+static int set_var(struct fbtft_par *par)
+{
+ /* par->info->fix.visual = FB_VISUAL_PSEUDOCOLOR; */
+ par->info->var.grayscale = 1;
+ par->info->var.red.offset = 0;
+ par->info->var.red.length = 8;
+ par->info->var.green.offset = 0;
+ par->info->var.green.length = 8;
+ par->info->var.blue.offset = 0;
+ par->info->var.blue.length = 8;
+ par->info->var.transp.offset = 0;
+ par->info->var.transp.length = 0;
+
+ switch (par->info->var.rotate) {
+ case 90:
+ /* Set RAM address control */
+ write_reg(par, 0x88
+ | (0x0 & 0x1) << 2 /* Increment positively */
+ | (0x1 & 0x1) << 1 /* Increment page first */
+ | (0x1 & 0x1)); /* Wrap around (default) */
+
+ /* Set LCD mapping */
+ write_reg(par, 0xC0
+ | (0x0 & 0x1) << 2 /* Mirror Y OFF */
+ | (0x0 & 0x1) << 1 /* Mirror X OFF */
+ | (0x0 & 0x1)); /* MS nibble last (default) */
+ break;
+ case 180:
+ /* Set RAM address control */
+ write_reg(par, 0x88
+ | (0x0 & 0x1) << 2 /* Increment positively */
+ | (0x0 & 0x1) << 1 /* Increment column first */
+ | (0x1 & 0x1)); /* Wrap around (default) */
+
+ /* Set LCD mapping */
+ write_reg(par, 0xC0
+ | (0x1 & 0x1) << 2 /* Mirror Y ON */
+ | (0x0 & 0x1) << 1 /* Mirror X OFF */
+ | (0x0 & 0x1)); /* MS nibble last (default) */
+ break;
+ case 270:
+ /* Set RAM address control */
+ write_reg(par, 0x88
+ | (0x0 & 0x1) << 2 /* Increment positively */
+ | (0x1 & 0x1) << 1 /* Increment page first */
+ | (0x1 & 0x1)); /* Wrap around (default) */
+
+ /* Set LCD mapping */
+ write_reg(par, 0xC0
+ | (0x1 & 0x1) << 2 /* Mirror Y ON */
+ | (0x1 & 0x1) << 1 /* Mirror X ON */
+ | (0x0 & 0x1)); /* MS nibble last (default) */
+ break;
+ default:
+ /* Set RAM address control */
+ write_reg(par, 0x88
+ | (0x0 & 0x1) << 2 /* Increment positively */
+ | (0x0 & 0x1) << 1 /* Increment column first */
+ | (0x1 & 0x1)); /* Wrap around (default) */
+
+ /* Set LCD mapping */
+ write_reg(par, 0xC0
+ | (0x0 & 0x1) << 2 /* Mirror Y OFF */
+ | (0x1 & 0x1) << 1 /* Mirror X ON */
+ | (0x0 & 0x1)); /* MS nibble last (default) */
+ break;
+ }
+
+ return 0;
+}
+
+static int write_vmem(struct fbtft_par *par, size_t offset, size_t len)
+{
+ u8 *vmem8 = (u8 *)(par->info->screen_buffer);
+ u8 *buf8 = (u8 *)(par->txbuf.buf);
+ u16 *buf16 = (u16 *)(par->txbuf.buf);
+ int line_length = par->info->fix.line_length;
+ int y_start = (offset / line_length);
+ int y_end = (offset + len - 1) / line_length;
+ int x, y, i;
+ int ret = 0;
+
+ switch (par->pdata->display.buswidth) {
+ case 8:
+ switch (par->info->var.rotate) {
+ case 90:
+ case 270:
+ i = y_start * line_length;
+ for (y = y_start; y <= y_end; y++) {
+ for (x = 0; x < line_length; x += 2) {
+ *buf8 = vmem8[i] >> 4;
+ *buf8 |= vmem8[i + 1] & 0xF0;
+ buf8++;
+ i += 2;
+ }
+ }
+ break;
+ default:
+ /* Must be even because pages are two lines */
+ y_start &= 0xFE;
+ i = y_start * line_length;
+ for (y = y_start; y <= y_end; y += 2) {
+ for (x = 0; x < line_length; x++) {
+ *buf8 = vmem8[i] >> 4;
+ *buf8 |= vmem8[i + line_length] & 0xF0;
+ buf8++;
+ i++;
+ }
+ i += line_length;
+ }
+ break;
+ }
+ gpio_set_value(par->gpio.dc, 1);
+
+ /* Write data */
+ ret = par->fbtftops.write(par, par->txbuf.buf, len / 2);
+ break;
+ case 9:
+ switch (par->info->var.rotate) {
+ case 90:
+ case 270:
+ i = y_start * line_length;
+ for (y = y_start; y <= y_end; y++) {
+ for (x = 0; x < line_length; x += 2) {
+ *buf16 = 0x100;
+ *buf16 |= vmem8[i] >> 4;
+ *buf16 |= vmem8[i + 1] & 0xF0;
+ buf16++;
+ i += 2;
+ }
+ }
+ break;
+ default:
+ /* Must be even because pages are two lines */
+ y_start &= 0xFE;
+ i = y_start * line_length;
+ for (y = y_start; y <= y_end; y += 2) {
+ for (x = 0; x < line_length; x++) {
+ *buf16 = 0x100;
+ *buf16 |= vmem8[i] >> 4;
+ *buf16 |= vmem8[i + line_length] & 0xF0;
+ buf16++;
+ i++;
+ }
+ i += line_length;
+ }
+ break;
+ }
+
+ /* Write data */
+ ret = par->fbtftops.write(par, par->txbuf.buf, len);
+ break;
+ default:
+ dev_err(par->info->device, "unsupported buswidth %d\n",
+ par->pdata->display.buswidth);
+ }
+
+ if (ret < 0)
+ dev_err(par->info->device, "write failed and returned: %d\n",
+ ret);
+
+ return ret;
+}
+
+static struct fbtft_display display = {
+ .txbuflen = -1,
+ .regwidth = 8,
+ .width = WIDTH,
+ .height = HEIGHT,
+ .bpp = BPP,
+ .fps = FPS,
+ .fbtftops = {
+ .write_vmem = write_vmem,
+ .init_display = init_display,
+ .set_addr_win = set_addr_win,
+ .set_var = set_var,
+ .blank = blank,
+ },
+};
+
+FBTFT_REGISTER_DRIVER(DRVNAME, "ultrachip,uc1611", &display);
+
+MODULE_ALIAS("spi:" DRVNAME);
+MODULE_ALIAS("platform:" DRVNAME);
+MODULE_ALIAS("spi:uc1611");
+MODULE_ALIAS("platform:uc1611");
+
+MODULE_DESCRIPTION("FB driver for the UC1611 LCD controller");
+MODULE_AUTHOR("Henri Chain");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff