root/drivers/staging/fbtft/fb_watterott.c

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DEFINITIONS

This source file includes following definitions.
  1. write_reg8_bus8
  2. write_vmem
  3. rgb565_to_rgb332
  4. write_vmem_8bit
  5. firmware_version
  6. init_display
  7. set_addr_win
  8. set_var
  9. verify_gpios
  10. backlight_chip_update_status
  11. register_chip_backlight

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * FB driver for the Watterott LCD Controller
   4  *
   5  * Copyright (C) 2013 Noralf Tronnes
   6  */
   7 
   8 #include <linux/module.h>
   9 #include <linux/kernel.h>
  10 #include <linux/init.h>
  11 #include <linux/gpio/consumer.h>
  12 #include <linux/delay.h>
  13 
  14 #include "fbtft.h"
  15 
  16 #define DRVNAME                 "fb_watterott"
  17 #define WIDTH                   320
  18 #define HEIGHT                  240
  19 #define FPS                     5
  20 #define TXBUFLEN                1024
  21 #define DEFAULT_BRIGHTNESS      50
  22 
  23 #define CMD_VERSION             0x01
  24 #define CMD_LCD_LED             0x10
  25 #define CMD_LCD_RESET           0x11
  26 #define CMD_LCD_ORIENTATION     0x20
  27 #define CMD_LCD_DRAWIMAGE       0x27
  28 #define COLOR_RGB323            8
  29 #define COLOR_RGB332            9
  30 #define COLOR_RGB233            10
  31 #define COLOR_RGB565            16
  32 
  33 static short mode = 565;
  34 module_param(mode, short, 0000);
  35 MODULE_PARM_DESC(mode, "RGB color transfer mode: 332, 565 (default)");
  36 
  37 static void write_reg8_bus8(struct fbtft_par *par, int len, ...)
  38 {
  39         va_list args;
  40         int i, ret;
  41         u8 *buf = par->buf;
  42 
  43         va_start(args, len);
  44         for (i = 0; i < len; i++)
  45                 *buf++ = (u8)va_arg(args, unsigned int);
  46         va_end(args);
  47 
  48         fbtft_par_dbg_hex(DEBUG_WRITE_REGISTER, par,
  49                           par->info->device, u8, par->buf,
  50                           len, "%s: ", __func__);
  51 
  52         ret = par->fbtftops.write(par, par->buf, len);
  53         if (ret < 0) {
  54                 dev_err(par->info->device,
  55                         "write() failed and returned %d\n", ret);
  56                 return;
  57         }
  58 }
  59 
  60 static int write_vmem(struct fbtft_par *par, size_t offset, size_t len)
  61 {
  62         unsigned int start_line, end_line;
  63         u16 *vmem16 = (u16 *)(par->info->screen_buffer + offset);
  64         __be16 *pos = par->txbuf.buf + 1;
  65         __be16 *buf16 = par->txbuf.buf + 10;
  66         int i, j;
  67         int ret = 0;
  68 
  69         start_line = offset / par->info->fix.line_length;
  70         end_line = start_line + (len / par->info->fix.line_length) - 1;
  71 
  72         /* Set command header. pos: x, y, w, h */
  73         ((u8 *)par->txbuf.buf)[0] = CMD_LCD_DRAWIMAGE;
  74         pos[0] = 0;
  75         pos[2] = cpu_to_be16(par->info->var.xres);
  76         pos[3] = cpu_to_be16(1);
  77         ((u8 *)par->txbuf.buf)[9] = COLOR_RGB565;
  78 
  79         for (i = start_line; i <= end_line; i++) {
  80                 pos[1] = cpu_to_be16(i);
  81                 for (j = 0; j < par->info->var.xres; j++)
  82                         buf16[j] = cpu_to_be16(*vmem16++);
  83                 ret = par->fbtftops.write(par,
  84                         par->txbuf.buf, 10 + par->info->fix.line_length);
  85                 if (ret < 0)
  86                         return ret;
  87                 udelay(300);
  88         }
  89 
  90         return 0;
  91 }
  92 
  93 static inline int rgb565_to_rgb332(u16 c)
  94 {
  95         return ((c & 0xE000) >> 8) | ((c & 000700) >> 6) | ((c & 0x0018) >> 3);
  96 }
  97 
  98 static int write_vmem_8bit(struct fbtft_par *par, size_t offset, size_t len)
  99 {
 100         unsigned int start_line, end_line;
 101         u16 *vmem16 = (u16 *)(par->info->screen_buffer + offset);
 102         __be16 *pos = par->txbuf.buf + 1;
 103         u8 *buf8 = par->txbuf.buf + 10;
 104         int i, j;
 105         int ret = 0;
 106 
 107         start_line = offset / par->info->fix.line_length;
 108         end_line = start_line + (len / par->info->fix.line_length) - 1;
 109 
 110         /* Set command header. pos: x, y, w, h */
 111         ((u8 *)par->txbuf.buf)[0] = CMD_LCD_DRAWIMAGE;
 112         pos[0] = 0;
 113         pos[2] = cpu_to_be16(par->info->var.xres);
 114         pos[3] = cpu_to_be16(1);
 115         ((u8 *)par->txbuf.buf)[9] = COLOR_RGB332;
 116 
 117         for (i = start_line; i <= end_line; i++) {
 118                 pos[1] = cpu_to_be16(i);
 119                 for (j = 0; j < par->info->var.xres; j++) {
 120                         buf8[j] = rgb565_to_rgb332(*vmem16);
 121                         vmem16++;
 122                 }
 123                 ret = par->fbtftops.write(par,
 124                         par->txbuf.buf, 10 + par->info->var.xres);
 125                 if (ret < 0)
 126                         return ret;
 127                 udelay(700);
 128         }
 129 
 130         return 0;
 131 }
 132 
 133 static unsigned int firmware_version(struct fbtft_par *par)
 134 {
 135         u8 rxbuf[4] = {0, };
 136 
 137         write_reg(par, CMD_VERSION);
 138         par->fbtftops.read(par, rxbuf, 4);
 139         if (rxbuf[1] != '.')
 140                 return 0;
 141 
 142         return (rxbuf[0] - '0') << 8 | (rxbuf[2] - '0') << 4 | (rxbuf[3] - '0');
 143 }
 144 
 145 static int init_display(struct fbtft_par *par)
 146 {
 147         int ret;
 148         unsigned int version;
 149         u8 save_mode;
 150 
 151         /* enable SPI interface by having CS and MOSI low during reset */
 152         save_mode = par->spi->mode;
 153         par->spi->mode |= SPI_CS_HIGH;
 154         ret = spi_setup(par->spi); /* set CS inactive low */
 155         if (ret) {
 156                 dev_err(par->info->device, "Could not set SPI_CS_HIGH\n");
 157                 return ret;
 158         }
 159         write_reg(par, 0x00); /* make sure mode is set */
 160 
 161         mdelay(50);
 162         par->fbtftops.reset(par);
 163         mdelay(1000);
 164         par->spi->mode = save_mode;
 165         ret = spi_setup(par->spi);
 166         if (ret) {
 167                 dev_err(par->info->device, "Could not restore SPI mode\n");
 168                 return ret;
 169         }
 170         write_reg(par, 0x00);
 171 
 172         version = firmware_version(par);
 173         fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "Firmware version: %x.%02x\n",
 174                       version >> 8, version & 0xFF);
 175 
 176         if (mode == 332)
 177                 par->fbtftops.write_vmem = write_vmem_8bit;
 178         return 0;
 179 }
 180 
 181 static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
 182 {
 183         /* not used on this controller */
 184 }
 185 
 186 static int set_var(struct fbtft_par *par)
 187 {
 188         u8 rotate;
 189 
 190         /* this controller rotates clock wise */
 191         switch (par->info->var.rotate) {
 192         case 90:
 193                 rotate = 27;
 194                 break;
 195         case 180:
 196                 rotate = 18;
 197                 break;
 198         case 270:
 199                 rotate = 9;
 200                 break;
 201         default:
 202                 rotate = 0;
 203         }
 204         write_reg(par, CMD_LCD_ORIENTATION, rotate);
 205 
 206         return 0;
 207 }
 208 
 209 static int verify_gpios(struct fbtft_par *par)
 210 {
 211         if (!par->gpio.reset) {
 212                 dev_err(par->info->device, "Missing 'reset' gpio. Aborting.\n");
 213                 return -EINVAL;
 214         }
 215         return 0;
 216 }
 217 
 218 #ifdef CONFIG_FB_BACKLIGHT
 219 static int backlight_chip_update_status(struct backlight_device *bd)
 220 {
 221         struct fbtft_par *par = bl_get_data(bd);
 222         int brightness = bd->props.brightness;
 223 
 224         fbtft_par_dbg(DEBUG_BACKLIGHT, par,
 225                       "%s: brightness=%d, power=%d, fb_blank=%d\n", __func__,
 226                       bd->props.brightness, bd->props.power,
 227                       bd->props.fb_blank);
 228 
 229         if (bd->props.power != FB_BLANK_UNBLANK)
 230                 brightness = 0;
 231 
 232         if (bd->props.fb_blank != FB_BLANK_UNBLANK)
 233                 brightness = 0;
 234 
 235         write_reg(par, CMD_LCD_LED, brightness);
 236 
 237         return 0;
 238 }
 239 
 240 static const struct backlight_ops bl_ops = {
 241         .update_status = backlight_chip_update_status,
 242 };
 243 
 244 static void register_chip_backlight(struct fbtft_par *par)
 245 {
 246         struct backlight_device *bd;
 247         struct backlight_properties bl_props = { 0, };
 248 
 249         bl_props.type = BACKLIGHT_RAW;
 250         bl_props.power = FB_BLANK_POWERDOWN;
 251         bl_props.max_brightness = 100;
 252         bl_props.brightness = DEFAULT_BRIGHTNESS;
 253 
 254         bd = backlight_device_register(dev_driver_string(par->info->device),
 255                                        par->info->device, par, &bl_ops,
 256                                        &bl_props);
 257         if (IS_ERR(bd)) {
 258                 dev_err(par->info->device,
 259                         "cannot register backlight device (%ld)\n",
 260                         PTR_ERR(bd));
 261                 return;
 262         }
 263         par->info->bl_dev = bd;
 264 
 265         if (!par->fbtftops.unregister_backlight)
 266                 par->fbtftops.unregister_backlight = fbtft_unregister_backlight;
 267 }
 268 #else
 269 #define register_chip_backlight NULL
 270 #endif
 271 
 272 static struct fbtft_display display = {
 273         .regwidth = 8,
 274         .buswidth = 8,
 275         .width = WIDTH,
 276         .height = HEIGHT,
 277         .fps = FPS,
 278         .txbuflen = TXBUFLEN,
 279         .fbtftops = {
 280                 .write_register = write_reg8_bus8,
 281                 .write_vmem = write_vmem,
 282                 .init_display = init_display,
 283                 .set_addr_win = set_addr_win,
 284                 .set_var = set_var,
 285                 .verify_gpios = verify_gpios,
 286                 .register_backlight = register_chip_backlight,
 287         },
 288 };
 289 
 290 FBTFT_REGISTER_DRIVER(DRVNAME, "watterott,openlcd", &display);
 291 
 292 MODULE_ALIAS("spi:" DRVNAME);
 293 
 294 MODULE_DESCRIPTION("FB driver for the Watterott LCD Controller");
 295 MODULE_AUTHOR("Noralf Tronnes");
 296 MODULE_LICENSE("GPL");

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