1// SPDX-License-Identifier: GPL-2.0 2 3#include <linux/backlight.h> 4#include <linux/module.h> 5#include <linux/kernel.h> 6#include <linux/init.h> 7#include <linux/spi/spi.h> 8#include <linux/delay.h> 9 10#include "fbtft.h" 11 12#define DRVNAME "fb_ssd1351" 13#define WIDTH 128 14#define HEIGHT 128 15#define GAMMA_NUM 1 16#define GAMMA_LEN 63 17#define DEFAULT_GAMMA "0 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 2 " \ 23 "2 2 2 2 2 2 2 2 " \ 24 "2 2 2 2 2 2 2" \ 25 26static void register_onboard_backlight(struct fbtft_par *par); 27 28static int init_display(struct fbtft_par *par) 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 write_reg(par, 0x15, xs, xe); 65 write_reg(par, 0x75, ys, ye); 66 write_reg(par, 0x5c); 67} 68 69static int set_var(struct fbtft_par *par) 70{ 71 unsigned int remap; 72 73 if (par->fbtftops.init_display != init_display) { 74 /* don't risk messing up register A0h */ 75 fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, 76 "%s: skipping since custom init_display() is used\n", 77 __func__); 78 return 0; 79 } 80 81 remap = 0x60 | (par->bgr << 2); /* Set Colour Depth */ 82 83 switch (par->info->var.rotate) { 84 case 0: 85 write_reg(par, 0xA0, remap | 0x00 | BIT(4)); 86 break; 87 case 270: 88 write_reg(par, 0xA0, remap | 0x03 | BIT(4)); 89 break; 90 case 180: 91 write_reg(par, 0xA0, remap | 0x02); 92 break; 93 case 90: 94 write_reg(par, 0xA0, remap | 0x01); 95 break; 96 } 97 98 return 0; 99} 100 101/* 102 * Grayscale Lookup Table 103 * GS1 - GS63 104 * The driver Gamma curve contains the relative values between the entries 105 * in the Lookup table. 106 * 107 * From datasheet: 108 * 8.8 Gray Scale Decoder 109 * 110 * there are total 180 Gamma Settings (Setting 0 to Setting 180) 111 * available for the Gray Scale table. 112 * 113 * The gray scale is defined in incremental way, with reference 114 * to the length of previous table entry: 115 * Setting of GS1 has to be >= 0 116 * Setting of GS2 has to be > Setting of GS1 +1 117 * Setting of GS3 has to be > Setting of GS2 +1 118 * : 119 * Setting of GS63 has to be > Setting of GS62 +1 120 * 121 */ 122static int set_gamma(struct fbtft_par *par, u32 *curves) 123{ 124 unsigned long tmp[GAMMA_NUM * GAMMA_LEN]; 125 int i, acc = 0; 126 127 for (i = 0; i < 63; i++) { 128 if (i > 0 && curves[i] < 2) { 129 dev_err(par->info->device, 130 "Illegal value in Grayscale Lookup Table at index %d : %d. Must be greater than 1\n", 131 i, curves[i]); 132 return -EINVAL; 133 } 134 acc += curves[i]; 135 tmp[i] = acc; 136 if (acc > 180) { 137 dev_err(par->info->device, 138 "Illegal value(s) in Grayscale Lookup Table. At index=%d : %d, the accumulated value has exceeded 180\n", 139 i, acc); 140 return -EINVAL; 141 } 142 } 143 144 write_reg(par, 0xB8, 145 tmp[0], tmp[1], tmp[2], tmp[3], 146 tmp[4], tmp[5], tmp[6], tmp[7], 147 tmp[8], tmp[9], tmp[10], tmp[11], 148 tmp[12], tmp[13], tmp[14], tmp[15], 149 tmp[16], tmp[17], tmp[18], tmp[19], 150 tmp[20], tmp[21], tmp[22], tmp[23], 151 tmp[24], tmp[25], tmp[26], tmp[27], 152 tmp[28], tmp[29], tmp[30], tmp[31], 153 tmp[32], tmp[33], tmp[34], tmp[35], 154 tmp[36], tmp[37], tmp[38], tmp[39], 155 tmp[40], tmp[41], tmp[42], tmp[43], 156 tmp[44], tmp[45], tmp[46], tmp[47], 157 tmp[48], tmp[49], tmp[50], tmp[51], 158 tmp[52], tmp[53], tmp[54], tmp[55], 159 tmp[56], tmp[57], tmp[58], tmp[59], 160 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=%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 176static struct fbtft_display display = { 177 .regwidth = 8, 178 .width = WIDTH, 179 .height = HEIGHT, 180 .gamma_num = GAMMA_NUM, 181 .gamma_len = GAMMA_LEN, 182 .gamma = DEFAULT_GAMMA, 183 .fbtftops = { 184 .init_display = init_display, 185 .set_addr_win = set_addr_win, 186 .set_var = set_var, 187 .set_gamma = set_gamma, 188 .blank = blank, 189 }, 190}; 191 192static int update_onboard_backlight(struct backlight_device *bd) 193{ 194 struct fbtft_par *par = bl_get_data(bd); 195 bool on; 196 197 fbtft_par_dbg(DEBUG_BACKLIGHT, par, 198 "%s: power=%d, fb_blank=%d\n", 199 __func__, bd->props.power, bd->props.fb_blank); 200 201 on = !backlight_is_blank(bd); 202 /* Onboard backlight connected to GPIO0 on SSD1351, GPIO1 unused */ 203 write_reg(par, 0xB5, on ? 0x03 : 0x02); 204 205 return 0; 206} 207 208static const struct backlight_ops bl_ops = { 209 .update_status = update_onboard_backlight, 210}; 211 212static void register_onboard_backlight(struct fbtft_par *par) 213{ 214 struct backlight_device *bd; 215 struct backlight_properties bl_props = { 0, }; 216 217 bl_props.type = BACKLIGHT_RAW; 218 bl_props.power = FB_BLANK_POWERDOWN; 219 220 bd = backlight_device_register(dev_driver_string(par->info->device), 221 par->info->device, par, &bl_ops, 222 &bl_props); 223 if (IS_ERR(bd)) { 224 dev_err(par->info->device, 225 "cannot register backlight device (%ld)\n", 226 PTR_ERR(bd)); 227 return; 228 } 229 par->info->bl_dev = bd; 230 231 if (!par->fbtftops.unregister_backlight) 232 par->fbtftops.unregister_backlight = fbtft_unregister_backlight; 233} 234 235FBTFT_REGISTER_DRIVER(DRVNAME, "solomon,ssd1351", &display); 236 237MODULE_ALIAS("spi:" DRVNAME); 238MODULE_ALIAS("platform:" DRVNAME); 239MODULE_ALIAS("spi:ssd1351"); 240MODULE_ALIAS("platform:ssd1351"); 241 242MODULE_DESCRIPTION("SSD1351 OLED Driver"); 243MODULE_AUTHOR("James Davies"); 244MODULE_LICENSE("GPL"); 245