| /* |
| * 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 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(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 = 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; |
| } |
| 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"); |