1#include <linux/module.h> 2#include <linux/kernel.h> 3#include <linux/init.h> 4#include <linux/gpio.h> 5#include <linux/spi/spi.h> 6#include <linux/delay.h> 7 8#include "fbtft.h" 9 10#define DRVNAME "fb_ssd1351" 11#define WIDTH 128 12#define HEIGHT 128 13#define GAMMA_NUM 1 14#define GAMMA_LEN 63 15#define DEFAULT_GAMMA "0 2 2 2 2 2 2 2 " \ 16 "2 2 2 2 2 2 2 2 " \ 17 "2 2 2 2 2 2 2 2 " \ 18 "2 2 2 2 2 2 2 2 " \ 19 "2 2 2 2 2 2 2 2 " \ 20 "2 2 2 2 2 2 2 2 " \ 21 "2 2 2 2 2 2 2 2 " \ 22 "2 2 2 2 2 2 2" \ 23 24static void register_onboard_backlight(struct fbtft_par *par); 25 26static int init_display(struct fbtft_par *par) 27{ 28 fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__); 29 30 if (par->pdata 31 && par->pdata->display.backlight == FBTFT_ONBOARD_BACKLIGHT) { 32 /* module uses onboard GPIO for panel power */ 33 par->fbtftops.register_backlight = register_onboard_backlight; 34 } 35 36 par->fbtftops.reset(par); 37 38 write_reg(par, 0xfd, 0x12); /* Command Lock */ 39 write_reg(par, 0xfd, 0xb1); /* Command Lock */ 40 write_reg(par, 0xae); /* Display Off */ 41 write_reg(par, 0xb3, 0xf1); /* Front Clock Div */ 42 write_reg(par, 0xca, 0x7f); /* Set Mux Ratio */ 43 write_reg(par, 0x15, 0x00, 0x7f); /* Set Column Address */ 44 write_reg(par, 0x75, 0x00, 0x7f); /* Set Row Address */ 45 write_reg(par, 0xa1, 0x00); /* Set Display Start Line */ 46 write_reg(par, 0xa2, 0x00); /* Set Display Offset */ 47 write_reg(par, 0xb5, 0x00); /* Set GPIO */ 48 write_reg(par, 0xab, 0x01); /* Set Function Selection */ 49 write_reg(par, 0xb1, 0x32); /* Set Phase Length */ 50 write_reg(par, 0xb4, 0xa0, 0xb5, 0x55); /* Set Segment Low Voltage */ 51 write_reg(par, 0xbb, 0x17); /* Set Precharge Voltage */ 52 write_reg(par, 0xbe, 0x05); /* Set VComH Voltage */ 53 write_reg(par, 0xc1, 0xc8, 0x80, 0xc8); /* Set Contrast */ 54 write_reg(par, 0xc7, 0x0f); /* Set Master Contrast */ 55 write_reg(par, 0xb6, 0x01); /* Set Second Precharge Period */ 56 write_reg(par, 0xa6); /* Set Display Mode Reset */ 57 write_reg(par, 0xaf); /* Set Sleep Mode Display On */ 58 59 return 0; 60} 61 62static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye) 63{ 64 fbtft_par_dbg(DEBUG_SET_ADDR_WIN, par, 65 "%s(xs=%d, ys=%d, xe=%d, ye=%d)\n", __func__, xs, ys, xe, ye); 66 67 write_reg(par, 0x15, xs, xe); 68 write_reg(par, 0x75, ys, ye); 69 write_reg(par, 0x5c); 70} 71 72static int set_var(struct fbtft_par *par) 73{ 74 unsigned remap; 75 76 fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__); 77 78 if (par->fbtftops.init_display != init_display) { 79 /* don't risk messing up register A0h */ 80 fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, 81 "%s: skipping since custom init_display() is used\n", 82 __func__); 83 return 0; 84 } 85 86 remap = 0x60 | (par->bgr << 2); /* Set Colour Depth */ 87 88 switch (par->info->var.rotate) { 89 case 0: 90 write_reg(par, 0xA0, remap | 0x00 | 1<<4); 91 break; 92 case 270: 93 write_reg(par, 0xA0, remap | 0x03 | 1<<4); 94 break; 95 case 180: 96 write_reg(par, 0xA0, remap | 0x02); 97 break; 98 case 90: 99 write_reg(par, 0xA0, remap | 0x01); 100 break; 101 } 102 103 return 0; 104} 105 106/* 107 Grayscale Lookup Table 108 GS1 - GS63 109 The driver Gamma curve contains the relative values between the entries 110 in the Lookup table. 111 112 From datasheet: 113 8.8 Gray Scale Decoder 114 115 there are total 180 Gamma Settings (Setting 0 to Setting 180) 116 available for the Gray Scale table. 117 118 The gray scale is defined in incremental way, with reference 119 to the length of previous table entry: 120 Setting of GS1 has to be >= 0 121 Setting of GS2 has to be > Setting of GS1 +1 122 Setting of GS3 has to be > Setting of GS2 +1 123 : 124 Setting of GS63 has to be > Setting of GS62 +1 125 126 127*/ 128static int set_gamma(struct fbtft_par *par, unsigned long *curves) 129{ 130 unsigned long tmp[GAMMA_NUM * GAMMA_LEN]; 131 int i, acc = 0; 132 133 fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__); 134 135 for (i = 0; i < 63; i++) { 136 if (i > 0 && curves[i] < 2) { 137 dev_err(par->info->device, 138 "Illegal value in Grayscale Lookup Table at index %d. " \ 139 "Must be greater than 1\n", i); 140 return -EINVAL; 141 } 142 acc += curves[i]; 143 tmp[i] = acc; 144 if (acc > 180) { 145 dev_err(par->info->device, 146 "Illegal value(s) in Grayscale Lookup Table. " \ 147 "At index=%d, the accumulated value has exceeded 180\n", i); 148 return -EINVAL; 149 } 150 } 151 152 write_reg(par, 0xB8, 153 tmp[0], tmp[1], tmp[2], tmp[3], tmp[4], tmp[5], tmp[6], tmp[7], 154 tmp[8], tmp[9], tmp[10], tmp[11], tmp[12], tmp[13], tmp[14], tmp[15], 155 tmp[16], tmp[17], tmp[18], tmp[19], tmp[20], tmp[21], tmp[22], tmp[23], 156 tmp[24], tmp[25], tmp[26], tmp[27], tmp[28], tmp[29], tmp[30], tmp[31], 157 tmp[32], tmp[33], tmp[34], tmp[35], tmp[36], tmp[37], tmp[38], tmp[39], 158 tmp[40], tmp[41], tmp[42], tmp[43], tmp[44], tmp[45], tmp[46], tmp[47], 159 tmp[48], tmp[49], tmp[50], tmp[51], tmp[52], tmp[53], tmp[54], tmp[55], 160 tmp[56], tmp[57], tmp[58], tmp[59], tmp[60], tmp[61], tmp[62]); 161 162 return 0; 163} 164 165static int blank(struct fbtft_par *par, bool on) 166{ 167 fbtft_par_dbg(DEBUG_BLANK, par, "%s(blank=%s)\n", 168 __func__, on ? "true" : "false"); 169 if (on) 170 write_reg(par, 0xAE); 171 else 172 write_reg(par, 0xAF); 173 return 0; 174} 175 176 177static struct fbtft_display display = { 178 .regwidth = 8, 179 .width = WIDTH, 180 .height = HEIGHT, 181 .gamma_num = GAMMA_NUM, 182 .gamma_len = GAMMA_LEN, 183 .gamma = DEFAULT_GAMMA, 184 .fbtftops = { 185 .init_display = init_display, 186 .set_addr_win = set_addr_win, 187 .set_var = set_var, 188 .set_gamma = set_gamma, 189 .blank = blank, 190 }, 191}; 192 193#ifdef CONFIG_FB_BACKLIGHT 194static int update_onboard_backlight(struct backlight_device *bd) 195{ 196 struct fbtft_par *par = bl_get_data(bd); 197 bool on; 198 199 fbtft_par_dbg(DEBUG_BACKLIGHT, par, 200 "%s: power=%d, fb_blank=%d\n", 201 __func__, bd->props.power, bd->props.fb_blank); 202 203 on = (bd->props.power == FB_BLANK_UNBLANK) 204 && (bd->props.fb_blank == FB_BLANK_UNBLANK); 205 /* Onboard backlight connected to GPIO0 on SSD1351, GPIO1 unused */ 206 write_reg(par, 0xB5, on ? 0x03 : 0x02); 207 208 return 0; 209} 210 211static void register_onboard_backlight(struct fbtft_par *par) 212{ 213 struct backlight_device *bd; 214 struct backlight_properties bl_props = { 0, }; 215 struct backlight_ops *bl_ops; 216 217 fbtft_par_dbg(DEBUG_BACKLIGHT, par, "%s()\n", __func__); 218 219 bl_ops = devm_kzalloc(par->info->device, sizeof(struct backlight_ops), 220 GFP_KERNEL); 221 if (!bl_ops) 222 return; 223 224 bl_ops->update_status = update_onboard_backlight; 225 bl_props.type = BACKLIGHT_RAW; 226 bl_props.power = FB_BLANK_POWERDOWN; 227 228 bd = backlight_device_register(dev_driver_string(par->info->device), 229 par->info->device, par, bl_ops, &bl_props); 230 if (IS_ERR(bd)) { 231 dev_err(par->info->device, 232 "cannot register backlight device (%ld)\n", 233 PTR_ERR(bd)); 234 return; 235 } 236 par->info->bl_dev = bd; 237 238 if (!par->fbtftops.unregister_backlight) 239 par->fbtftops.unregister_backlight = fbtft_unregister_backlight; 240} 241#else 242static void register_onboard_backlight(struct fbtft_par *par) { }; 243#endif 244 245 246FBTFT_REGISTER_DRIVER(DRVNAME, "solomon,ssd1351", &display); 247 248MODULE_ALIAS("spi:" DRVNAME); 249MODULE_ALIAS("platform:" DRVNAME); 250MODULE_ALIAS("spi:ssd1351"); 251MODULE_ALIAS("platform:ssd1351"); 252 253MODULE_DESCRIPTION("SSD1351 OLED Driver"); 254MODULE_AUTHOR("James Davies"); 255MODULE_LICENSE("GPL"); 256