// SPDX-License-Identifier: GPL-2.0+ /* * FB driver for the UltraChip UC1611 LCD controller * * The display is 4-bit grayscale (16 shades) 240x160. * * Copyright (C) 2015 Henri Chain */ #include #include #include #include #include #include #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 int ratio = 2; module_param(ratio, uint, 0000); MODULE_PARM_DESC(ratio, "BR[1:0] Bias voltage ratio: 0-3 (default: 2)"); static unsigned int gain = 3; module_param(gain, uint, 0000); MODULE_PARM_DESC(gain, "GN[1:0] Bias voltage gain: 0-3 (default: 3)"); static unsigned int pot = 16; module_param(pot, uint, 0000); 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 int temp; module_param(temp, uint, 0000); 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 int load = 1; module_param(load, uint, 0000); 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 int pump = 3; module_param(pump, uint, 0000); 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=%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 = par->txbuf.buf; u16 *buf16 = 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; } gpiod_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");