Maxime Ripard | a2ed00d | 2012-12-07 12:30:38 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Driver for the Solomon SSD1307 OLED controler |
| 3 | * |
| 4 | * Copyright 2012 Free Electrons |
| 5 | * |
| 6 | * Licensed under the GPLv2 or later. |
| 7 | */ |
| 8 | |
| 9 | #include <linux/module.h> |
| 10 | #include <linux/kernel.h> |
| 11 | #include <linux/i2c.h> |
| 12 | #include <linux/fb.h> |
| 13 | #include <linux/uaccess.h> |
| 14 | #include <linux/of_device.h> |
| 15 | #include <linux/of_gpio.h> |
| 16 | #include <linux/pwm.h> |
| 17 | #include <linux/delay.h> |
| 18 | |
| 19 | #define SSD1307FB_WIDTH 96 |
| 20 | #define SSD1307FB_HEIGHT 16 |
| 21 | |
| 22 | #define SSD1307FB_DATA 0x40 |
| 23 | #define SSD1307FB_COMMAND 0x80 |
| 24 | |
| 25 | #define SSD1307FB_CONTRAST 0x81 |
| 26 | #define SSD1307FB_SEG_REMAP_ON 0xa1 |
| 27 | #define SSD1307FB_DISPLAY_OFF 0xae |
| 28 | #define SSD1307FB_DISPLAY_ON 0xaf |
| 29 | #define SSD1307FB_START_PAGE_ADDRESS 0xb0 |
| 30 | |
| 31 | struct ssd1307fb_par { |
| 32 | struct i2c_client *client; |
| 33 | struct fb_info *info; |
| 34 | struct pwm_device *pwm; |
| 35 | u32 pwm_period; |
| 36 | int reset; |
| 37 | }; |
| 38 | |
Greg Kroah-Hartman | 48c68c4 | 2012-12-21 13:07:39 -0800 | [diff] [blame] | 39 | static struct fb_fix_screeninfo ssd1307fb_fix = { |
Maxime Ripard | a2ed00d | 2012-12-07 12:30:38 -0800 | [diff] [blame] | 40 | .id = "Solomon SSD1307", |
| 41 | .type = FB_TYPE_PACKED_PIXELS, |
| 42 | .visual = FB_VISUAL_MONO10, |
| 43 | .xpanstep = 0, |
| 44 | .ypanstep = 0, |
| 45 | .ywrapstep = 0, |
| 46 | .line_length = SSD1307FB_WIDTH / 8, |
| 47 | .accel = FB_ACCEL_NONE, |
| 48 | }; |
| 49 | |
Greg Kroah-Hartman | 48c68c4 | 2012-12-21 13:07:39 -0800 | [diff] [blame] | 50 | static struct fb_var_screeninfo ssd1307fb_var = { |
Maxime Ripard | a2ed00d | 2012-12-07 12:30:38 -0800 | [diff] [blame] | 51 | .xres = SSD1307FB_WIDTH, |
| 52 | .yres = SSD1307FB_HEIGHT, |
| 53 | .xres_virtual = SSD1307FB_WIDTH, |
| 54 | .yres_virtual = SSD1307FB_HEIGHT, |
| 55 | .bits_per_pixel = 1, |
| 56 | }; |
| 57 | |
| 58 | static int ssd1307fb_write_array(struct i2c_client *client, u8 type, u8 *cmd, u32 len) |
| 59 | { |
| 60 | u8 *buf; |
| 61 | int ret = 0; |
| 62 | |
| 63 | buf = kzalloc(len + 1, GFP_KERNEL); |
| 64 | if (!buf) { |
| 65 | dev_err(&client->dev, "Couldn't allocate sending buffer.\n"); |
| 66 | return -ENOMEM; |
| 67 | } |
| 68 | |
| 69 | buf[0] = type; |
| 70 | memcpy(buf + 1, cmd, len); |
| 71 | |
| 72 | ret = i2c_master_send(client, buf, len + 1); |
| 73 | if (ret != len + 1) { |
| 74 | dev_err(&client->dev, "Couldn't send I2C command.\n"); |
| 75 | goto error; |
| 76 | } |
| 77 | |
| 78 | error: |
| 79 | kfree(buf); |
| 80 | return ret; |
| 81 | } |
| 82 | |
| 83 | static inline int ssd1307fb_write_cmd_array(struct i2c_client *client, u8 *cmd, u32 len) |
| 84 | { |
| 85 | return ssd1307fb_write_array(client, SSD1307FB_COMMAND, cmd, len); |
| 86 | } |
| 87 | |
| 88 | static inline int ssd1307fb_write_cmd(struct i2c_client *client, u8 cmd) |
| 89 | { |
| 90 | return ssd1307fb_write_cmd_array(client, &cmd, 1); |
| 91 | } |
| 92 | |
| 93 | static inline int ssd1307fb_write_data_array(struct i2c_client *client, u8 *cmd, u32 len) |
| 94 | { |
| 95 | return ssd1307fb_write_array(client, SSD1307FB_DATA, cmd, len); |
| 96 | } |
| 97 | |
| 98 | static inline int ssd1307fb_write_data(struct i2c_client *client, u8 data) |
| 99 | { |
| 100 | return ssd1307fb_write_data_array(client, &data, 1); |
| 101 | } |
| 102 | |
| 103 | static void ssd1307fb_update_display(struct ssd1307fb_par *par) |
| 104 | { |
| 105 | u8 *vmem = par->info->screen_base; |
| 106 | int i, j, k; |
| 107 | |
| 108 | /* |
| 109 | * The screen is divided in pages, each having a height of 8 |
| 110 | * pixels, and the width of the screen. When sending a byte of |
| 111 | * data to the controller, it gives the 8 bits for the current |
| 112 | * column. I.e, the first byte are the 8 bits of the first |
| 113 | * column, then the 8 bits for the second column, etc. |
| 114 | * |
| 115 | * |
| 116 | * Representation of the screen, assuming it is 5 bits |
| 117 | * wide. Each letter-number combination is a bit that controls |
| 118 | * one pixel. |
| 119 | * |
| 120 | * A0 A1 A2 A3 A4 |
| 121 | * B0 B1 B2 B3 B4 |
| 122 | * C0 C1 C2 C3 C4 |
| 123 | * D0 D1 D2 D3 D4 |
| 124 | * E0 E1 E2 E3 E4 |
| 125 | * F0 F1 F2 F3 F4 |
| 126 | * G0 G1 G2 G3 G4 |
| 127 | * H0 H1 H2 H3 H4 |
| 128 | * |
| 129 | * If you want to update this screen, you need to send 5 bytes: |
| 130 | * (1) A0 B0 C0 D0 E0 F0 G0 H0 |
| 131 | * (2) A1 B1 C1 D1 E1 F1 G1 H1 |
| 132 | * (3) A2 B2 C2 D2 E2 F2 G2 H2 |
| 133 | * (4) A3 B3 C3 D3 E3 F3 G3 H3 |
| 134 | * (5) A4 B4 C4 D4 E4 F4 G4 H4 |
| 135 | */ |
| 136 | |
| 137 | for (i = 0; i < (SSD1307FB_HEIGHT / 8); i++) { |
| 138 | ssd1307fb_write_cmd(par->client, SSD1307FB_START_PAGE_ADDRESS + (i + 1)); |
| 139 | ssd1307fb_write_cmd(par->client, 0x00); |
| 140 | ssd1307fb_write_cmd(par->client, 0x10); |
| 141 | |
| 142 | for (j = 0; j < SSD1307FB_WIDTH; j++) { |
| 143 | u8 buf = 0; |
| 144 | for (k = 0; k < 8; k++) { |
| 145 | u32 page_length = SSD1307FB_WIDTH * i; |
| 146 | u32 index = page_length + (SSD1307FB_WIDTH * k + j) / 8; |
| 147 | u8 byte = *(vmem + index); |
Maxime Ripard | 552f0cc | 2013-01-11 14:31:43 -0800 | [diff] [blame^] | 148 | u8 bit = byte & (1 << (j % 8)); |
| 149 | bit = bit >> (j % 8); |
Maxime Ripard | a2ed00d | 2012-12-07 12:30:38 -0800 | [diff] [blame] | 150 | buf |= bit << k; |
| 151 | } |
| 152 | ssd1307fb_write_data(par->client, buf); |
| 153 | } |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | |
| 158 | static ssize_t ssd1307fb_write(struct fb_info *info, const char __user *buf, |
| 159 | size_t count, loff_t *ppos) |
| 160 | { |
| 161 | struct ssd1307fb_par *par = info->par; |
| 162 | unsigned long total_size; |
| 163 | unsigned long p = *ppos; |
| 164 | u8 __iomem *dst; |
| 165 | |
| 166 | total_size = info->fix.smem_len; |
| 167 | |
| 168 | if (p > total_size) |
| 169 | return -EINVAL; |
| 170 | |
| 171 | if (count + p > total_size) |
| 172 | count = total_size - p; |
| 173 | |
| 174 | if (!count) |
| 175 | return -EINVAL; |
| 176 | |
| 177 | dst = (void __force *) (info->screen_base + p); |
| 178 | |
| 179 | if (copy_from_user(dst, buf, count)) |
| 180 | return -EFAULT; |
| 181 | |
| 182 | ssd1307fb_update_display(par); |
| 183 | |
| 184 | *ppos += count; |
| 185 | |
| 186 | return count; |
| 187 | } |
| 188 | |
| 189 | static void ssd1307fb_fillrect(struct fb_info *info, const struct fb_fillrect *rect) |
| 190 | { |
| 191 | struct ssd1307fb_par *par = info->par; |
| 192 | sys_fillrect(info, rect); |
| 193 | ssd1307fb_update_display(par); |
| 194 | } |
| 195 | |
| 196 | static void ssd1307fb_copyarea(struct fb_info *info, const struct fb_copyarea *area) |
| 197 | { |
| 198 | struct ssd1307fb_par *par = info->par; |
| 199 | sys_copyarea(info, area); |
| 200 | ssd1307fb_update_display(par); |
| 201 | } |
| 202 | |
| 203 | static void ssd1307fb_imageblit(struct fb_info *info, const struct fb_image *image) |
| 204 | { |
| 205 | struct ssd1307fb_par *par = info->par; |
| 206 | sys_imageblit(info, image); |
| 207 | ssd1307fb_update_display(par); |
| 208 | } |
| 209 | |
| 210 | static struct fb_ops ssd1307fb_ops = { |
| 211 | .owner = THIS_MODULE, |
| 212 | .fb_read = fb_sys_read, |
| 213 | .fb_write = ssd1307fb_write, |
| 214 | .fb_fillrect = ssd1307fb_fillrect, |
| 215 | .fb_copyarea = ssd1307fb_copyarea, |
| 216 | .fb_imageblit = ssd1307fb_imageblit, |
| 217 | }; |
| 218 | |
| 219 | static void ssd1307fb_deferred_io(struct fb_info *info, |
| 220 | struct list_head *pagelist) |
| 221 | { |
| 222 | ssd1307fb_update_display(info->par); |
| 223 | } |
| 224 | |
| 225 | static struct fb_deferred_io ssd1307fb_defio = { |
| 226 | .delay = HZ, |
| 227 | .deferred_io = ssd1307fb_deferred_io, |
| 228 | }; |
| 229 | |
Greg Kroah-Hartman | 48c68c4 | 2012-12-21 13:07:39 -0800 | [diff] [blame] | 230 | static int ssd1307fb_probe(struct i2c_client *client, |
| 231 | const struct i2c_device_id *id) |
Maxime Ripard | a2ed00d | 2012-12-07 12:30:38 -0800 | [diff] [blame] | 232 | { |
| 233 | struct fb_info *info; |
| 234 | u32 vmem_size = SSD1307FB_WIDTH * SSD1307FB_HEIGHT / 8; |
| 235 | struct ssd1307fb_par *par; |
| 236 | u8 *vmem; |
| 237 | int ret; |
| 238 | |
| 239 | if (!client->dev.of_node) { |
| 240 | dev_err(&client->dev, "No device tree data found!\n"); |
| 241 | return -EINVAL; |
| 242 | } |
| 243 | |
| 244 | info = framebuffer_alloc(sizeof(struct ssd1307fb_par), &client->dev); |
| 245 | if (!info) { |
| 246 | dev_err(&client->dev, "Couldn't allocate framebuffer.\n"); |
| 247 | return -ENOMEM; |
| 248 | } |
| 249 | |
| 250 | vmem = devm_kzalloc(&client->dev, vmem_size, GFP_KERNEL); |
| 251 | if (!vmem) { |
| 252 | dev_err(&client->dev, "Couldn't allocate graphical memory.\n"); |
| 253 | ret = -ENOMEM; |
| 254 | goto fb_alloc_error; |
| 255 | } |
| 256 | |
| 257 | info->fbops = &ssd1307fb_ops; |
| 258 | info->fix = ssd1307fb_fix; |
| 259 | info->fbdefio = &ssd1307fb_defio; |
| 260 | |
| 261 | info->var = ssd1307fb_var; |
| 262 | info->var.red.length = 1; |
| 263 | info->var.red.offset = 0; |
| 264 | info->var.green.length = 1; |
| 265 | info->var.green.offset = 0; |
| 266 | info->var.blue.length = 1; |
| 267 | info->var.blue.offset = 0; |
| 268 | |
| 269 | info->screen_base = (u8 __force __iomem *)vmem; |
| 270 | info->fix.smem_start = (unsigned long)vmem; |
| 271 | info->fix.smem_len = vmem_size; |
| 272 | |
| 273 | fb_deferred_io_init(info); |
| 274 | |
| 275 | par = info->par; |
| 276 | par->info = info; |
| 277 | par->client = client; |
| 278 | |
| 279 | par->reset = of_get_named_gpio(client->dev.of_node, |
| 280 | "reset-gpios", 0); |
| 281 | if (!gpio_is_valid(par->reset)) { |
| 282 | ret = -EINVAL; |
| 283 | goto reset_oled_error; |
| 284 | } |
| 285 | |
| 286 | ret = devm_gpio_request_one(&client->dev, par->reset, |
| 287 | GPIOF_OUT_INIT_HIGH, |
| 288 | "oled-reset"); |
| 289 | if (ret) { |
| 290 | dev_err(&client->dev, |
| 291 | "failed to request gpio %d: %d\n", |
| 292 | par->reset, ret); |
| 293 | goto reset_oled_error; |
| 294 | } |
| 295 | |
| 296 | par->pwm = pwm_get(&client->dev, NULL); |
| 297 | if (IS_ERR(par->pwm)) { |
| 298 | dev_err(&client->dev, "Could not get PWM from device tree!\n"); |
| 299 | ret = PTR_ERR(par->pwm); |
| 300 | goto pwm_error; |
| 301 | } |
| 302 | |
| 303 | par->pwm_period = pwm_get_period(par->pwm); |
| 304 | |
| 305 | dev_dbg(&client->dev, "Using PWM%d with a %dns period.\n", par->pwm->pwm, par->pwm_period); |
| 306 | |
| 307 | ret = register_framebuffer(info); |
| 308 | if (ret) { |
| 309 | dev_err(&client->dev, "Couldn't register the framebuffer\n"); |
| 310 | goto fbreg_error; |
| 311 | } |
| 312 | |
| 313 | i2c_set_clientdata(client, info); |
| 314 | |
| 315 | /* Reset the screen */ |
| 316 | gpio_set_value(par->reset, 0); |
| 317 | udelay(4); |
| 318 | gpio_set_value(par->reset, 1); |
| 319 | udelay(4); |
| 320 | |
| 321 | /* Enable the PWM */ |
| 322 | pwm_config(par->pwm, par->pwm_period / 2, par->pwm_period); |
| 323 | pwm_enable(par->pwm); |
| 324 | |
| 325 | /* Map column 127 of the OLED to segment 0 */ |
| 326 | ret = ssd1307fb_write_cmd(client, SSD1307FB_SEG_REMAP_ON); |
| 327 | if (ret < 0) { |
| 328 | dev_err(&client->dev, "Couldn't remap the screen.\n"); |
| 329 | goto remap_error; |
| 330 | } |
| 331 | |
| 332 | /* Turn on the display */ |
| 333 | ret = ssd1307fb_write_cmd(client, SSD1307FB_DISPLAY_ON); |
| 334 | if (ret < 0) { |
| 335 | dev_err(&client->dev, "Couldn't turn the display on.\n"); |
| 336 | goto remap_error; |
| 337 | } |
| 338 | |
| 339 | dev_info(&client->dev, "fb%d: %s framebuffer device registered, using %d bytes of video memory\n", info->node, info->fix.id, vmem_size); |
| 340 | |
| 341 | return 0; |
| 342 | |
| 343 | remap_error: |
| 344 | unregister_framebuffer(info); |
| 345 | pwm_disable(par->pwm); |
| 346 | fbreg_error: |
| 347 | pwm_put(par->pwm); |
| 348 | pwm_error: |
| 349 | reset_oled_error: |
| 350 | fb_deferred_io_cleanup(info); |
| 351 | fb_alloc_error: |
| 352 | framebuffer_release(info); |
| 353 | return ret; |
| 354 | } |
| 355 | |
Greg Kroah-Hartman | 48c68c4 | 2012-12-21 13:07:39 -0800 | [diff] [blame] | 356 | static int ssd1307fb_remove(struct i2c_client *client) |
Maxime Ripard | a2ed00d | 2012-12-07 12:30:38 -0800 | [diff] [blame] | 357 | { |
| 358 | struct fb_info *info = i2c_get_clientdata(client); |
| 359 | struct ssd1307fb_par *par = info->par; |
| 360 | |
| 361 | unregister_framebuffer(info); |
| 362 | pwm_disable(par->pwm); |
| 363 | pwm_put(par->pwm); |
| 364 | fb_deferred_io_cleanup(info); |
| 365 | framebuffer_release(info); |
| 366 | |
| 367 | return 0; |
| 368 | } |
| 369 | |
| 370 | static const struct i2c_device_id ssd1307fb_i2c_id[] = { |
| 371 | { "ssd1307fb", 0 }, |
| 372 | { } |
| 373 | }; |
| 374 | MODULE_DEVICE_TABLE(i2c, ssd1307fb_i2c_id); |
| 375 | |
| 376 | static const struct of_device_id ssd1307fb_of_match[] = { |
| 377 | { .compatible = "solomon,ssd1307fb-i2c" }, |
| 378 | {}, |
| 379 | }; |
| 380 | MODULE_DEVICE_TABLE(of, ssd1307fb_of_match); |
| 381 | |
| 382 | static struct i2c_driver ssd1307fb_driver = { |
| 383 | .probe = ssd1307fb_probe, |
Greg Kroah-Hartman | 48c68c4 | 2012-12-21 13:07:39 -0800 | [diff] [blame] | 384 | .remove = ssd1307fb_remove, |
Maxime Ripard | a2ed00d | 2012-12-07 12:30:38 -0800 | [diff] [blame] | 385 | .id_table = ssd1307fb_i2c_id, |
| 386 | .driver = { |
| 387 | .name = "ssd1307fb", |
| 388 | .of_match_table = of_match_ptr(ssd1307fb_of_match), |
| 389 | .owner = THIS_MODULE, |
| 390 | }, |
| 391 | }; |
| 392 | |
| 393 | module_i2c_driver(ssd1307fb_driver); |
| 394 | |
| 395 | MODULE_DESCRIPTION("FB driver for the Solomon SSD1307 OLED controler"); |
| 396 | MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>"); |
| 397 | MODULE_LICENSE("GPL"); |