c440eee1a7
This switches the fbtft driver to use GPIO descriptors rather than numerical gpios: Utilize the GPIO library's intrinsic handling of OF GPIOs and polarity. If the line is flagged active low, gpiolib will deal with this. Remove gpios from platform device structure. Neither assign statically numbers to gpios in platform device nor allow gpios to be parsed as module parameters. Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
332 lines
8.1 KiB
C
332 lines
8.1 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* FB driver for the UltraChip UC1611 LCD controller
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*
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* The display is 4-bit grayscale (16 shades) 240x160.
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*
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* Copyright (C) 2015 Henri Chain
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/gpio/consumer.h>
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#include <linux/spi/spi.h>
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#include <linux/delay.h>
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#include "fbtft.h"
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#define DRVNAME "fb_uc1611"
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#define WIDTH 240
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#define HEIGHT 160
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#define BPP 8
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#define FPS 40
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/*
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* LCD voltage is a combination of ratio, gain, pot and temp
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*
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* V_LCD = V_BIAS * ratio
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* V_LCD = (C_V0 + C_PM × pot) * (1 + (T - 25) * temp)
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* C_V0 and C_PM depend on ratio and gain
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* T is ambient temperature
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*/
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/* BR -> actual ratio: 0-3 -> 5, 10, 11, 13 */
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static unsigned int ratio = 2;
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module_param(ratio, uint, 0000);
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MODULE_PARM_DESC(ratio, "BR[1:0] Bias voltage ratio: 0-3 (default: 2)");
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static unsigned int gain = 3;
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module_param(gain, uint, 0000);
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MODULE_PARM_DESC(gain, "GN[1:0] Bias voltage gain: 0-3 (default: 3)");
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static unsigned int pot = 16;
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module_param(pot, uint, 0000);
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MODULE_PARM_DESC(pot, "PM[6:0] Bias voltage pot.: 0-63 (default: 16)");
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/* TC -> % compensation per deg C: 0-3 -> -.05, -.10, -.015, -.20 */
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static unsigned int temp;
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module_param(temp, uint, 0000);
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MODULE_PARM_DESC(temp, "TC[1:0] Temperature compensation: 0-3 (default: 0)");
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/* PC[1:0] -> LCD capacitance: 0-3 -> <20nF, 20-28 nF, 29-40 nF, 40-56 nF */
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static unsigned int load = 1;
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module_param(load, uint, 0000);
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MODULE_PARM_DESC(load, "PC[1:0] Panel Loading: 0-3 (default: 1)");
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/* PC[3:2] -> V_LCD: 0, 1, 3 -> ext., int. with ratio = 5, int. standard */
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static unsigned int pump = 3;
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module_param(pump, uint, 0000);
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MODULE_PARM_DESC(pump, "PC[3:2] Pump control: 0,1,3 (default: 3)");
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static int init_display(struct fbtft_par *par)
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{
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int ret;
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/* Set CS active high */
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par->spi->mode |= SPI_CS_HIGH;
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ret = spi_setup(par->spi);
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if (ret) {
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dev_err(par->info->device, "Could not set SPI_CS_HIGH\n");
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return ret;
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}
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/* Reset controller */
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write_reg(par, 0xE2);
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/* Set bias ratio */
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write_reg(par, 0xE8 | (ratio & 0x03));
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/* Set bias gain and potentiometer */
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write_reg(par, 0x81);
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write_reg(par, (gain & 0x03) << 6 | (pot & 0x3F));
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/* Set temperature compensation */
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write_reg(par, 0x24 | (temp & 0x03));
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/* Set panel loading */
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write_reg(par, 0x28 | (load & 0x03));
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/* Set pump control */
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write_reg(par, 0x2C | (pump & 0x03));
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/* Set inverse display */
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write_reg(par, 0xA6 | (0x01 & 0x01));
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/* Set 4-bit grayscale mode */
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write_reg(par, 0xD0 | (0x02 & 0x03));
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/* Set Display enable */
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write_reg(par, 0xA8 | 0x07);
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return 0;
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}
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static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
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{
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switch (par->info->var.rotate) {
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case 90:
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case 270:
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/* Set column address */
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write_reg(par, ys & 0x0F);
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write_reg(par, 0x10 | (ys >> 4));
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/* Set page address (divide xs by 2) (not used by driver) */
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write_reg(par, 0x60 | ((xs >> 1) & 0x0F));
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write_reg(par, 0x70 | (xs >> 5));
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break;
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default:
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/* Set column address (not used by driver) */
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write_reg(par, xs & 0x0F);
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write_reg(par, 0x10 | (xs >> 4));
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/* Set page address (divide ys by 2) */
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write_reg(par, 0x60 | ((ys >> 1) & 0x0F));
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write_reg(par, 0x70 | (ys >> 5));
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break;
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}
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}
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static int blank(struct fbtft_par *par, bool on)
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{
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fbtft_par_dbg(DEBUG_BLANK, par, "(%s=%s)\n",
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__func__, on ? "true" : "false");
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if (on)
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write_reg(par, 0xA8 | 0x00);
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else
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write_reg(par, 0xA8 | 0x07);
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return 0;
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}
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static int set_var(struct fbtft_par *par)
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{
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/* par->info->fix.visual = FB_VISUAL_PSEUDOCOLOR; */
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par->info->var.grayscale = 1;
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par->info->var.red.offset = 0;
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par->info->var.red.length = 8;
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par->info->var.green.offset = 0;
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par->info->var.green.length = 8;
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par->info->var.blue.offset = 0;
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par->info->var.blue.length = 8;
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par->info->var.transp.offset = 0;
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par->info->var.transp.length = 0;
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switch (par->info->var.rotate) {
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case 90:
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/* Set RAM address control */
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write_reg(par, 0x88
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| (0x0 & 0x1) << 2 /* Increment positively */
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| (0x1 & 0x1) << 1 /* Increment page first */
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| (0x1 & 0x1)); /* Wrap around (default) */
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/* Set LCD mapping */
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write_reg(par, 0xC0
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| (0x0 & 0x1) << 2 /* Mirror Y OFF */
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| (0x0 & 0x1) << 1 /* Mirror X OFF */
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| (0x0 & 0x1)); /* MS nibble last (default) */
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break;
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case 180:
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/* Set RAM address control */
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write_reg(par, 0x88
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| (0x0 & 0x1) << 2 /* Increment positively */
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| (0x0 & 0x1) << 1 /* Increment column first */
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| (0x1 & 0x1)); /* Wrap around (default) */
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/* Set LCD mapping */
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write_reg(par, 0xC0
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| (0x1 & 0x1) << 2 /* Mirror Y ON */
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| (0x0 & 0x1) << 1 /* Mirror X OFF */
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| (0x0 & 0x1)); /* MS nibble last (default) */
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break;
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case 270:
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/* Set RAM address control */
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write_reg(par, 0x88
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| (0x0 & 0x1) << 2 /* Increment positively */
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| (0x1 & 0x1) << 1 /* Increment page first */
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| (0x1 & 0x1)); /* Wrap around (default) */
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/* Set LCD mapping */
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write_reg(par, 0xC0
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| (0x1 & 0x1) << 2 /* Mirror Y ON */
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| (0x1 & 0x1) << 1 /* Mirror X ON */
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| (0x0 & 0x1)); /* MS nibble last (default) */
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break;
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default:
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/* Set RAM address control */
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write_reg(par, 0x88
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| (0x0 & 0x1) << 2 /* Increment positively */
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| (0x0 & 0x1) << 1 /* Increment column first */
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| (0x1 & 0x1)); /* Wrap around (default) */
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/* Set LCD mapping */
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write_reg(par, 0xC0
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| (0x0 & 0x1) << 2 /* Mirror Y OFF */
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| (0x1 & 0x1) << 1 /* Mirror X ON */
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| (0x0 & 0x1)); /* MS nibble last (default) */
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break;
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}
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return 0;
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}
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static int write_vmem(struct fbtft_par *par, size_t offset, size_t len)
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{
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u8 *vmem8 = (u8 *)(par->info->screen_buffer);
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u8 *buf8 = par->txbuf.buf;
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u16 *buf16 = par->txbuf.buf;
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int line_length = par->info->fix.line_length;
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int y_start = offset / line_length;
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int y_end = (offset + len - 1) / line_length;
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int x, y, i;
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int ret = 0;
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switch (par->pdata->display.buswidth) {
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case 8:
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switch (par->info->var.rotate) {
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case 90:
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case 270:
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i = y_start * line_length;
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for (y = y_start; y <= y_end; y++) {
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for (x = 0; x < line_length; x += 2) {
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*buf8 = vmem8[i] >> 4;
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*buf8 |= vmem8[i + 1] & 0xF0;
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buf8++;
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i += 2;
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}
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}
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break;
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default:
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/* Must be even because pages are two lines */
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y_start &= 0xFE;
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i = y_start * line_length;
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for (y = y_start; y <= y_end; y += 2) {
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for (x = 0; x < line_length; x++) {
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*buf8 = vmem8[i] >> 4;
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*buf8 |= vmem8[i + line_length] & 0xF0;
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buf8++;
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i++;
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}
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i += line_length;
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}
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break;
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}
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gpiod_set_value(par->gpio.dc, 1);
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/* Write data */
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ret = par->fbtftops.write(par, par->txbuf.buf, len / 2);
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break;
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case 9:
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switch (par->info->var.rotate) {
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case 90:
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case 270:
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i = y_start * line_length;
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for (y = y_start; y <= y_end; y++) {
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for (x = 0; x < line_length; x += 2) {
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*buf16 = 0x100;
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*buf16 |= vmem8[i] >> 4;
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*buf16 |= vmem8[i + 1] & 0xF0;
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buf16++;
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i += 2;
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}
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}
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break;
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default:
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/* Must be even because pages are two lines */
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y_start &= 0xFE;
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i = y_start * line_length;
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for (y = y_start; y <= y_end; y += 2) {
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for (x = 0; x < line_length; x++) {
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*buf16 = 0x100;
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*buf16 |= vmem8[i] >> 4;
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*buf16 |= vmem8[i + line_length] & 0xF0;
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buf16++;
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i++;
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}
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i += line_length;
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}
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break;
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}
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/* Write data */
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ret = par->fbtftops.write(par, par->txbuf.buf, len);
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break;
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default:
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dev_err(par->info->device, "unsupported buswidth %d\n",
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par->pdata->display.buswidth);
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}
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if (ret < 0)
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dev_err(par->info->device, "write failed and returned: %d\n",
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ret);
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return ret;
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}
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static struct fbtft_display display = {
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.txbuflen = -1,
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.regwidth = 8,
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.width = WIDTH,
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.height = HEIGHT,
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.bpp = BPP,
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.fps = FPS,
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.fbtftops = {
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.write_vmem = write_vmem,
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.init_display = init_display,
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.set_addr_win = set_addr_win,
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.set_var = set_var,
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.blank = blank,
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},
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};
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FBTFT_REGISTER_DRIVER(DRVNAME, "ultrachip,uc1611", &display);
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MODULE_ALIAS("spi:" DRVNAME);
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MODULE_ALIAS("platform:" DRVNAME);
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MODULE_ALIAS("spi:uc1611");
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MODULE_ALIAS("platform:uc1611");
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MODULE_DESCRIPTION("FB driver for the UC1611 LCD controller");
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MODULE_AUTHOR("Henri Chain");
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MODULE_LICENSE("GPL");
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