808 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Driver for the Solomon SSD1307 OLED controller4 *5 * Copyright 2012 Free Electrons6 */7 8#include <linux/backlight.h>9#include <linux/delay.h>10#include <linux/fb.h>11#include <linux/gpio/consumer.h>12#include <linux/i2c.h>13#include <linux/kernel.h>14#include <linux/module.h>15#include <linux/property.h>16#include <linux/pwm.h>17#include <linux/uaccess.h>18#include <linux/regulator/consumer.h>19 20#define SSD1307FB_DATA 0x4021#define SSD1307FB_COMMAND 0x8022 23#define SSD1307FB_SET_ADDRESS_MODE 0x2024#define SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL (0x00)25#define SSD1307FB_SET_ADDRESS_MODE_VERTICAL (0x01)26#define SSD1307FB_SET_ADDRESS_MODE_PAGE (0x02)27#define SSD1307FB_SET_COL_RANGE 0x2128#define SSD1307FB_SET_PAGE_RANGE 0x2229#define SSD1307FB_CONTRAST 0x8130#define SSD1307FB_SET_LOOKUP_TABLE 0x9131#define SSD1307FB_CHARGE_PUMP 0x8d32#define SSD1307FB_SEG_REMAP_ON 0xa133#define SSD1307FB_DISPLAY_OFF 0xae34#define SSD1307FB_SET_MULTIPLEX_RATIO 0xa835#define SSD1307FB_DISPLAY_ON 0xaf36#define SSD1307FB_START_PAGE_ADDRESS 0xb037#define SSD1307FB_SET_DISPLAY_OFFSET 0xd338#define SSD1307FB_SET_CLOCK_FREQ 0xd539#define SSD1307FB_SET_AREA_COLOR_MODE 0xd840#define SSD1307FB_SET_PRECHARGE_PERIOD 0xd941#define SSD1307FB_SET_COM_PINS_CONFIG 0xda42#define SSD1307FB_SET_VCOMH 0xdb43 44#define MAX_CONTRAST 25545 46#define REFRESHRATE 147 48static u_int refreshrate = REFRESHRATE;49module_param(refreshrate, uint, 0);50 51struct ssd1307fb_deviceinfo {52 u32 default_vcomh;53 u32 default_dclk_div;54 u32 default_dclk_frq;55 bool need_pwm;56 bool need_chargepump;57};58 59struct ssd1307fb_par {60 unsigned area_color_enable : 1;61 unsigned com_invdir : 1;62 unsigned com_lrremap : 1;63 unsigned com_seq : 1;64 unsigned lookup_table_set : 1;65 unsigned low_power : 1;66 unsigned seg_remap : 1;67 u32 com_offset;68 u32 contrast;69 u32 dclk_div;70 u32 dclk_frq;71 const struct ssd1307fb_deviceinfo *device_info;72 struct i2c_client *client;73 u32 height;74 struct fb_info *info;75 u8 lookup_table[4];76 u32 page_offset;77 u32 col_offset;78 u32 prechargep1;79 u32 prechargep2;80 struct pwm_device *pwm;81 struct gpio_desc *reset;82 struct regulator *vbat_reg;83 u32 vcomh;84 u32 width;85 /* Cached address ranges */86 u8 col_start;87 u8 col_end;88 u8 page_start;89 u8 page_end;90};91 92struct ssd1307fb_array {93 u8 type;94 u8 data[];95};96 97static const struct fb_fix_screeninfo ssd1307fb_fix = {98 .id = "Solomon SSD1307",99 .type = FB_TYPE_PACKED_PIXELS,100 .visual = FB_VISUAL_MONO10,101 .xpanstep = 0,102 .ypanstep = 0,103 .ywrapstep = 0,104 .accel = FB_ACCEL_NONE,105};106 107static const struct fb_var_screeninfo ssd1307fb_var = {108 .bits_per_pixel = 1,109 .red = { .length = 1 },110 .green = { .length = 1 },111 .blue = { .length = 1 },112};113 114static struct ssd1307fb_array *ssd1307fb_alloc_array(u32 len, u8 type)115{116 struct ssd1307fb_array *array;117 118 array = kzalloc(sizeof(struct ssd1307fb_array) + len, GFP_KERNEL);119 if (!array)120 return NULL;121 122 array->type = type;123 124 return array;125}126 127static int ssd1307fb_write_array(struct i2c_client *client,128 struct ssd1307fb_array *array, u32 len)129{130 int ret;131 132 len += sizeof(struct ssd1307fb_array);133 134 ret = i2c_master_send(client, (u8 *)array, len);135 if (ret != len) {136 dev_err(&client->dev, "Couldn't send I2C command.\n");137 return ret;138 }139 140 return 0;141}142 143static inline int ssd1307fb_write_cmd(struct i2c_client *client, u8 cmd)144{145 struct ssd1307fb_array *array;146 int ret;147 148 array = ssd1307fb_alloc_array(1, SSD1307FB_COMMAND);149 if (!array)150 return -ENOMEM;151 152 array->data[0] = cmd;153 154 ret = ssd1307fb_write_array(client, array, 1);155 kfree(array);156 157 return ret;158}159 160static int ssd1307fb_set_col_range(struct ssd1307fb_par *par, u8 col_start,161 u8 cols)162{163 u8 col_end = col_start + cols - 1;164 int ret;165 166 if (col_start == par->col_start && col_end == par->col_end)167 return 0;168 169 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE);170 if (ret < 0)171 return ret;172 173 ret = ssd1307fb_write_cmd(par->client, col_start);174 if (ret < 0)175 return ret;176 177 ret = ssd1307fb_write_cmd(par->client, col_end);178 if (ret < 0)179 return ret;180 181 par->col_start = col_start;182 par->col_end = col_end;183 return 0;184}185 186static int ssd1307fb_set_page_range(struct ssd1307fb_par *par, u8 page_start,187 u8 pages)188{189 u8 page_end = page_start + pages - 1;190 int ret;191 192 if (page_start == par->page_start && page_end == par->page_end)193 return 0;194 195 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE);196 if (ret < 0)197 return ret;198 199 ret = ssd1307fb_write_cmd(par->client, page_start);200 if (ret < 0)201 return ret;202 203 ret = ssd1307fb_write_cmd(par->client, page_end);204 if (ret < 0)205 return ret;206 207 par->page_start = page_start;208 par->page_end = page_end;209 return 0;210}211 212static int ssd1307fb_update_rect(struct ssd1307fb_par *par, unsigned int x,213 unsigned int y, unsigned int width,214 unsigned int height)215{216 struct ssd1307fb_array *array;217 u8 *vmem = par->info->screen_buffer;218 unsigned int line_length = par->info->fix.line_length;219 unsigned int pages = DIV_ROUND_UP(y % 8 + height, 8);220 u32 array_idx = 0;221 int ret, i, j, k;222 223 array = ssd1307fb_alloc_array(width * pages, SSD1307FB_DATA);224 if (!array)225 return -ENOMEM;226 227 /*228 * The screen is divided in pages, each having a height of 8229 * pixels, and the width of the screen. When sending a byte of230 * data to the controller, it gives the 8 bits for the current231 * column. I.e, the first byte are the 8 bits of the first232 * column, then the 8 bits for the second column, etc.233 *234 *235 * Representation of the screen, assuming it is 5 bits236 * wide. Each letter-number combination is a bit that controls237 * one pixel.238 *239 * A0 A1 A2 A3 A4240 * B0 B1 B2 B3 B4241 * C0 C1 C2 C3 C4242 * D0 D1 D2 D3 D4243 * E0 E1 E2 E3 E4244 * F0 F1 F2 F3 F4245 * G0 G1 G2 G3 G4246 * H0 H1 H2 H3 H4247 *248 * If you want to update this screen, you need to send 5 bytes:249 * (1) A0 B0 C0 D0 E0 F0 G0 H0250 * (2) A1 B1 C1 D1 E1 F1 G1 H1251 * (3) A2 B2 C2 D2 E2 F2 G2 H2252 * (4) A3 B3 C3 D3 E3 F3 G3 H3253 * (5) A4 B4 C4 D4 E4 F4 G4 H4254 */255 256 ret = ssd1307fb_set_col_range(par, par->col_offset + x, width);257 if (ret < 0)258 goto out_free;259 260 ret = ssd1307fb_set_page_range(par, par->page_offset + y / 8, pages);261 if (ret < 0)262 goto out_free;263 264 for (i = y / 8; i < y / 8 + pages; i++) {265 int m = 8;266 267 /* Last page may be partial */268 if (8 * (i + 1) > par->height)269 m = par->height % 8;270 for (j = x; j < x + width; j++) {271 u8 data = 0;272 273 for (k = 0; k < m; k++) {274 u8 byte = vmem[(8 * i + k) * line_length +275 j / 8];276 u8 bit = (byte >> (j % 8)) & 1;277 data |= bit << k;278 }279 array->data[array_idx++] = data;280 }281 }282 283 ret = ssd1307fb_write_array(par->client, array, width * pages);284 285out_free:286 kfree(array);287 return ret;288}289 290static int ssd1307fb_update_display(struct ssd1307fb_par *par)291{292 return ssd1307fb_update_rect(par, 0, 0, par->width, par->height);293}294 295static int ssd1307fb_blank(int blank_mode, struct fb_info *info)296{297 struct ssd1307fb_par *par = info->par;298 299 if (blank_mode != FB_BLANK_UNBLANK)300 return ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_OFF);301 else302 return ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON);303}304 305static void ssd1307fb_defio_damage_range(struct fb_info *info, off_t off, size_t len)306{307 struct ssd1307fb_par *par = info->par;308 309 ssd1307fb_update_display(par);310}311 312static void ssd1307fb_defio_damage_area(struct fb_info *info, u32 x, u32 y,313 u32 width, u32 height)314{315 struct ssd1307fb_par *par = info->par;316 317 ssd1307fb_update_rect(par, x, y, width, height);318}319 320FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(ssd1307fb,321 ssd1307fb_defio_damage_range,322 ssd1307fb_defio_damage_area)323 324static const struct fb_ops ssd1307fb_ops = {325 .owner = THIS_MODULE,326 FB_DEFAULT_DEFERRED_OPS(ssd1307fb),327 .fb_blank = ssd1307fb_blank,328};329 330static void ssd1307fb_deferred_io(struct fb_info *info, struct list_head *pagereflist)331{332 ssd1307fb_update_display(info->par);333}334 335static int ssd1307fb_init(struct ssd1307fb_par *par)336{337 struct pwm_state pwmstate;338 int ret;339 u32 precharge, dclk, com_invdir, compins;340 341 if (par->device_info->need_pwm) {342 par->pwm = pwm_get(&par->client->dev, NULL);343 if (IS_ERR(par->pwm)) {344 dev_err(&par->client->dev, "Could not get PWM from device tree!\n");345 return PTR_ERR(par->pwm);346 }347 348 pwm_init_state(par->pwm, &pwmstate);349 pwm_set_relative_duty_cycle(&pwmstate, 50, 100);350 pwm_apply_might_sleep(par->pwm, &pwmstate);351 352 /* Enable the PWM */353 pwm_enable(par->pwm);354 355 dev_dbg(&par->client->dev, "Using PWM %s with a %lluns period.\n",356 par->pwm->label, pwm_get_period(par->pwm));357 }358 359 /* Set initial contrast */360 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST);361 if (ret < 0)362 return ret;363 364 ret = ssd1307fb_write_cmd(par->client, par->contrast);365 if (ret < 0)366 return ret;367 368 /* Set segment re-map */369 if (par->seg_remap) {370 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SEG_REMAP_ON);371 if (ret < 0)372 return ret;373 }374 375 /* Set COM direction */376 com_invdir = 0xc0 | par->com_invdir << 3;377 ret = ssd1307fb_write_cmd(par->client, com_invdir);378 if (ret < 0)379 return ret;380 381 /* Set multiplex ratio value */382 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_MULTIPLEX_RATIO);383 if (ret < 0)384 return ret;385 386 ret = ssd1307fb_write_cmd(par->client, par->height - 1);387 if (ret < 0)388 return ret;389 390 /* set display offset value */391 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_DISPLAY_OFFSET);392 if (ret < 0)393 return ret;394 395 ret = ssd1307fb_write_cmd(par->client, par->com_offset);396 if (ret < 0)397 return ret;398 399 /* Set clock frequency */400 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_CLOCK_FREQ);401 if (ret < 0)402 return ret;403 404 dclk = ((par->dclk_div - 1) & 0xf) | (par->dclk_frq & 0xf) << 4;405 ret = ssd1307fb_write_cmd(par->client, dclk);406 if (ret < 0)407 return ret;408 409 /* Set Area Color Mode ON/OFF & Low Power Display Mode */410 if (par->area_color_enable || par->low_power) {411 u32 mode;412 413 ret = ssd1307fb_write_cmd(par->client,414 SSD1307FB_SET_AREA_COLOR_MODE);415 if (ret < 0)416 return ret;417 418 mode = (par->area_color_enable ? 0x30 : 0) |419 (par->low_power ? 5 : 0);420 ret = ssd1307fb_write_cmd(par->client, mode);421 if (ret < 0)422 return ret;423 }424 425 /* Set precharge period in number of ticks from the internal clock */426 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PRECHARGE_PERIOD);427 if (ret < 0)428 return ret;429 430 precharge = (par->prechargep1 & 0xf) | (par->prechargep2 & 0xf) << 4;431 ret = ssd1307fb_write_cmd(par->client, precharge);432 if (ret < 0)433 return ret;434 435 /* Set COM pins configuration */436 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COM_PINS_CONFIG);437 if (ret < 0)438 return ret;439 440 compins = 0x02 | !par->com_seq << 4 | par->com_lrremap << 5;441 ret = ssd1307fb_write_cmd(par->client, compins);442 if (ret < 0)443 return ret;444 445 /* Set VCOMH */446 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_VCOMH);447 if (ret < 0)448 return ret;449 450 ret = ssd1307fb_write_cmd(par->client, par->vcomh);451 if (ret < 0)452 return ret;453 454 /* Turn on the DC-DC Charge Pump */455 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CHARGE_PUMP);456 if (ret < 0)457 return ret;458 459 ret = ssd1307fb_write_cmd(par->client,460 BIT(4) | (par->device_info->need_chargepump ? BIT(2) : 0));461 if (ret < 0)462 return ret;463 464 /* Set lookup table */465 if (par->lookup_table_set) {466 int i;467 468 ret = ssd1307fb_write_cmd(par->client,469 SSD1307FB_SET_LOOKUP_TABLE);470 if (ret < 0)471 return ret;472 473 for (i = 0; i < ARRAY_SIZE(par->lookup_table); ++i) {474 u8 val = par->lookup_table[i];475 476 if (val < 31 || val > 63)477 dev_warn(&par->client->dev,478 "lookup table index %d value out of range 31 <= %d <= 63\n",479 i, val);480 ret = ssd1307fb_write_cmd(par->client, val);481 if (ret < 0)482 return ret;483 }484 }485 486 /* Switch to horizontal addressing mode */487 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_ADDRESS_MODE);488 if (ret < 0)489 return ret;490 491 ret = ssd1307fb_write_cmd(par->client,492 SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL);493 if (ret < 0)494 return ret;495 496 /* Clear the screen */497 ret = ssd1307fb_update_display(par);498 if (ret < 0)499 return ret;500 501 /* Turn on the display */502 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON);503 if (ret < 0)504 return ret;505 506 return 0;507}508 509static int ssd1307fb_update_bl(struct backlight_device *bdev)510{511 struct ssd1307fb_par *par = bl_get_data(bdev);512 int ret;513 int brightness = bdev->props.brightness;514 515 par->contrast = brightness;516 517 ret = ssd1307fb_write_cmd(par->client, SSD1307FB_CONTRAST);518 if (ret < 0)519 return ret;520 ret = ssd1307fb_write_cmd(par->client, par->contrast);521 if (ret < 0)522 return ret;523 return 0;524}525 526static int ssd1307fb_get_brightness(struct backlight_device *bdev)527{528 struct ssd1307fb_par *par = bl_get_data(bdev);529 530 return par->contrast;531}532 533static const struct backlight_ops ssd1307fb_bl_ops = {534 .options = BL_CORE_SUSPENDRESUME,535 .update_status = ssd1307fb_update_bl,536 .get_brightness = ssd1307fb_get_brightness,537};538 539static struct ssd1307fb_deviceinfo ssd1307fb_ssd1305_deviceinfo = {540 .default_vcomh = 0x34,541 .default_dclk_div = 1,542 .default_dclk_frq = 7,543};544 545static struct ssd1307fb_deviceinfo ssd1307fb_ssd1306_deviceinfo = {546 .default_vcomh = 0x20,547 .default_dclk_div = 1,548 .default_dclk_frq = 8,549 .need_chargepump = 1,550};551 552static struct ssd1307fb_deviceinfo ssd1307fb_ssd1307_deviceinfo = {553 .default_vcomh = 0x20,554 .default_dclk_div = 2,555 .default_dclk_frq = 12,556 .need_pwm = 1,557};558 559static struct ssd1307fb_deviceinfo ssd1307fb_ssd1309_deviceinfo = {560 .default_vcomh = 0x34,561 .default_dclk_div = 1,562 .default_dclk_frq = 10,563};564 565static const struct of_device_id ssd1307fb_of_match[] = {566 {567 .compatible = "solomon,ssd1305fb-i2c",568 .data = (void *)&ssd1307fb_ssd1305_deviceinfo,569 },570 {571 .compatible = "solomon,ssd1306fb-i2c",572 .data = (void *)&ssd1307fb_ssd1306_deviceinfo,573 },574 {575 .compatible = "solomon,ssd1307fb-i2c",576 .data = (void *)&ssd1307fb_ssd1307_deviceinfo,577 },578 {579 .compatible = "solomon,ssd1309fb-i2c",580 .data = (void *)&ssd1307fb_ssd1309_deviceinfo,581 },582 {},583};584MODULE_DEVICE_TABLE(of, ssd1307fb_of_match);585 586static int ssd1307fb_probe(struct i2c_client *client)587{588 struct device *dev = &client->dev;589 struct backlight_device *bl;590 struct fb_info *info;591 struct fb_deferred_io *ssd1307fb_defio;592 u32 vmem_size;593 struct ssd1307fb_par *par;594 void *vmem;595 int ret;596 597 info = framebuffer_alloc(sizeof(struct ssd1307fb_par), dev);598 if (!info)599 return -ENOMEM;600 601 par = info->par;602 par->info = info;603 par->client = client;604 605 par->device_info = device_get_match_data(dev);606 607 par->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);608 if (IS_ERR(par->reset)) {609 ret = dev_err_probe(dev, PTR_ERR(par->reset),610 "failed to get reset gpio\n");611 goto fb_alloc_error;612 }613 614 par->vbat_reg = devm_regulator_get_optional(dev, "vbat");615 if (IS_ERR(par->vbat_reg)) {616 ret = PTR_ERR(par->vbat_reg);617 if (ret == -ENODEV) {618 par->vbat_reg = NULL;619 } else {620 dev_err_probe(dev, ret, "failed to get VBAT regulator\n");621 goto fb_alloc_error;622 }623 }624 625 if (device_property_read_u32(dev, "solomon,width", &par->width))626 par->width = 96;627 628 if (device_property_read_u32(dev, "solomon,height", &par->height))629 par->height = 16;630 631 if (device_property_read_u32(dev, "solomon,page-offset", &par->page_offset))632 par->page_offset = 1;633 634 if (device_property_read_u32(dev, "solomon,col-offset", &par->col_offset))635 par->col_offset = 0;636 637 if (device_property_read_u32(dev, "solomon,com-offset", &par->com_offset))638 par->com_offset = 0;639 640 if (device_property_read_u32(dev, "solomon,prechargep1", &par->prechargep1))641 par->prechargep1 = 2;642 643 if (device_property_read_u32(dev, "solomon,prechargep2", &par->prechargep2))644 par->prechargep2 = 2;645 646 if (!device_property_read_u8_array(dev, "solomon,lookup-table",647 par->lookup_table,648 ARRAY_SIZE(par->lookup_table)))649 par->lookup_table_set = 1;650 651 par->seg_remap = !device_property_read_bool(dev, "solomon,segment-no-remap");652 par->com_seq = device_property_read_bool(dev, "solomon,com-seq");653 par->com_lrremap = device_property_read_bool(dev, "solomon,com-lrremap");654 par->com_invdir = device_property_read_bool(dev, "solomon,com-invdir");655 par->area_color_enable =656 device_property_read_bool(dev, "solomon,area-color-enable");657 par->low_power = device_property_read_bool(dev, "solomon,low-power");658 659 par->contrast = 127;660 par->vcomh = par->device_info->default_vcomh;661 662 /* Setup display timing */663 if (device_property_read_u32(dev, "solomon,dclk-div", &par->dclk_div))664 par->dclk_div = par->device_info->default_dclk_div;665 if (device_property_read_u32(dev, "solomon,dclk-frq", &par->dclk_frq))666 par->dclk_frq = par->device_info->default_dclk_frq;667 668 vmem_size = DIV_ROUND_UP(par->width, 8) * par->height;669 670 vmem = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,671 get_order(vmem_size));672 if (!vmem) {673 dev_err(dev, "Couldn't allocate graphical memory.\n");674 ret = -ENOMEM;675 goto fb_alloc_error;676 }677 678 ssd1307fb_defio = devm_kzalloc(dev, sizeof(*ssd1307fb_defio),679 GFP_KERNEL);680 if (!ssd1307fb_defio) {681 dev_err(dev, "Couldn't allocate deferred io.\n");682 ret = -ENOMEM;683 goto fb_alloc_error;684 }685 686 ssd1307fb_defio->delay = HZ / refreshrate;687 ssd1307fb_defio->deferred_io = ssd1307fb_deferred_io;688 689 info->fbops = &ssd1307fb_ops;690 info->fix = ssd1307fb_fix;691 info->fix.line_length = DIV_ROUND_UP(par->width, 8);692 info->fbdefio = ssd1307fb_defio;693 694 info->var = ssd1307fb_var;695 info->var.xres = par->width;696 info->var.xres_virtual = par->width;697 info->var.yres = par->height;698 info->var.yres_virtual = par->height;699 700 info->screen_buffer = vmem;701 info->fix.smem_start = __pa(vmem);702 info->fix.smem_len = vmem_size;703 704 fb_deferred_io_init(info);705 706 i2c_set_clientdata(client, info);707 708 if (par->reset) {709 /* Reset the screen */710 gpiod_set_value_cansleep(par->reset, 1);711 udelay(4);712 gpiod_set_value_cansleep(par->reset, 0);713 udelay(4);714 }715 716 if (par->vbat_reg) {717 ret = regulator_enable(par->vbat_reg);718 if (ret) {719 dev_err(dev, "failed to enable VBAT: %d\n", ret);720 goto reset_oled_error;721 }722 }723 724 ret = ssd1307fb_init(par);725 if (ret)726 goto regulator_enable_error;727 728 bl = backlight_device_register("ssd1307fb-bl", dev, par, &ssd1307fb_bl_ops,729 NULL);730 if (IS_ERR(bl)) {731 ret = PTR_ERR(bl);732 dev_err(dev, "unable to register backlight device: %d\n", ret);733 goto panel_init_error;734 }735 info->bl_dev = bl;736 737 ret = register_framebuffer(info);738 if (ret) {739 dev_err(dev, "Couldn't register the framebuffer\n");740 goto fb_init_error;741 }742 743 bl->props.brightness = par->contrast;744 bl->props.max_brightness = MAX_CONTRAST;745 746 dev_info(dev, "fb%d: %s framebuffer device registered, using %d bytes of video memory\n", info->node, info->fix.id, vmem_size);747 748 return 0;749 750fb_init_error:751 backlight_device_unregister(bl);752panel_init_error:753 pwm_disable(par->pwm);754 pwm_put(par->pwm);755regulator_enable_error:756 if (par->vbat_reg)757 regulator_disable(par->vbat_reg);758reset_oled_error:759 fb_deferred_io_cleanup(info);760fb_alloc_error:761 framebuffer_release(info);762 return ret;763}764 765static void ssd1307fb_remove(struct i2c_client *client)766{767 struct fb_info *info = i2c_get_clientdata(client);768 struct ssd1307fb_par *par = info->par;769 770 ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_OFF);771 772 backlight_device_unregister(info->bl_dev);773 774 unregister_framebuffer(info);775 pwm_disable(par->pwm);776 pwm_put(par->pwm);777 if (par->vbat_reg)778 regulator_disable(par->vbat_reg);779 fb_deferred_io_cleanup(info);780 __free_pages(__va(info->fix.smem_start), get_order(info->fix.smem_len));781 framebuffer_release(info);782}783 784static const struct i2c_device_id ssd1307fb_i2c_id[] = {785 { "ssd1305fb" },786 { "ssd1306fb" },787 { "ssd1307fb" },788 { "ssd1309fb" },789 { }790};791MODULE_DEVICE_TABLE(i2c, ssd1307fb_i2c_id);792 793static struct i2c_driver ssd1307fb_driver = {794 .probe = ssd1307fb_probe,795 .remove = ssd1307fb_remove,796 .id_table = ssd1307fb_i2c_id,797 .driver = {798 .name = "ssd1307fb",799 .of_match_table = ssd1307fb_of_match,800 },801};802 803module_i2c_driver(ssd1307fb_driver);804 805MODULE_DESCRIPTION("FB driver for the Solomon SSD1307 OLED controller");806MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");807MODULE_LICENSE("GPL");808