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>
10 #define DRVNAME "fb_ssd1351"
15 #define DEFAULT_GAMMA "0 2 2 2 2 2 2 2 " \
24 static void register_onboard_backlight(struct fbtft_par *par);
26 static int init_display(struct fbtft_par *par)
28 fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
31 && par->pdata->display.backlight == FBTFT_ONBOARD_BACKLIGHT) {
32 /* module uses onboard GPIO for panel power */
33 par->fbtftops.register_backlight = register_onboard_backlight;
36 par->fbtftops.reset(par);
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 */
62 static void set_addr_win(struct fbtft_par *par, int xs, int ys, int xe, int ye)
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);
67 write_reg(par, 0x15, xs, xe);
68 write_reg(par, 0x75, ys, ye);
72 static int set_var(struct fbtft_par *par)
76 fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
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",
86 remap = 0x60 | (par->bgr << 2); /* Set Colour Depth */
88 switch (par->info->var.rotate) {
90 write_reg(par, 0xA0, remap | 0x00 | 1<<4);
93 write_reg(par, 0xA0, remap | 0x03 | 1<<4);
96 write_reg(par, 0xA0, remap | 0x02);
99 write_reg(par, 0xA0, remap | 0x01);
107 Grayscale Lookup Table
109 The driver Gamma curve contains the relative values between the entries
113 8.8 Gray Scale Decoder
115 there are total 180 Gamma Settings (Setting 0 to Setting 180)
116 available for the Gray Scale table.
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
124 Setting of GS63 has to be > Setting of GS62 +1
128 static int set_gamma(struct fbtft_par *par, unsigned long *curves)
130 unsigned long tmp[GAMMA_NUM * GAMMA_LEN];
133 fbtft_par_dbg(DEBUG_INIT_DISPLAY, par, "%s()\n", __func__);
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);
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);
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]);
165 static int blank(struct fbtft_par *par, bool on)
167 fbtft_par_dbg(DEBUG_BLANK, par, "%s(blank=%s)\n",
168 __func__, on ? "true" : "false");
170 write_reg(par, 0xAE);
172 write_reg(par, 0xAF);
177 static struct fbtft_display display = {
181 .gamma_num = GAMMA_NUM,
182 .gamma_len = GAMMA_LEN,
183 .gamma = DEFAULT_GAMMA,
185 .init_display = init_display,
186 .set_addr_win = set_addr_win,
188 .set_gamma = set_gamma,
193 #ifdef CONFIG_FB_BACKLIGHT
194 static int update_onboard_backlight(struct backlight_device *bd)
196 struct fbtft_par *par = bl_get_data(bd);
199 fbtft_par_dbg(DEBUG_BACKLIGHT, par,
200 "%s: power=%d, fb_blank=%d\n",
201 __func__, bd->props.power, bd->props.fb_blank);
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);
211 static void register_onboard_backlight(struct fbtft_par *par)
213 struct backlight_device *bd;
214 struct backlight_properties bl_props = { 0, };
215 struct backlight_ops *bl_ops;
217 fbtft_par_dbg(DEBUG_BACKLIGHT, par, "%s()\n", __func__);
219 bl_ops = devm_kzalloc(par->info->device, sizeof(struct backlight_ops),
224 bl_ops->update_status = update_onboard_backlight;
225 bl_props.type = BACKLIGHT_RAW;
226 bl_props.power = FB_BLANK_POWERDOWN;
228 bd = backlight_device_register(dev_driver_string(par->info->device),
229 par->info->device, par, bl_ops, &bl_props);
231 dev_err(par->info->device,
232 "cannot register backlight device (%ld)\n",
236 par->info->bl_dev = bd;
238 if (!par->fbtftops.unregister_backlight)
239 par->fbtftops.unregister_backlight = fbtft_unregister_backlight;
242 static void register_onboard_backlight(struct fbtft_par *par) { };
246 FBTFT_REGISTER_DRIVER(DRVNAME, "solomon,ssd1351", &display);
248 MODULE_ALIAS("spi:" DRVNAME);
249 MODULE_ALIAS("platform:" DRVNAME);
250 MODULE_ALIAS("spi:ssd1351");
251 MODULE_ALIAS("platform:ssd1351");
253 MODULE_DESCRIPTION("SSD1351 OLED Driver");
254 MODULE_AUTHOR("James Davies");
255 MODULE_LICENSE("GPL");