2 * Driver for the Solomon SSD1307 OLED controller
4 * Copyright 2012 Free Electrons
6 * Licensed under the GPLv2 or later.
9 #include <linux/backlight.h>
10 #include <linux/delay.h>
12 #include <linux/i2c.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/of_device.h>
16 #include <linux/of_gpio.h>
17 #include <linux/pwm.h>
18 #include <linux/uaccess.h>
20 #define SSD1307FB_DATA 0x40
21 #define SSD1307FB_COMMAND 0x80
23 #define SSD1307FB_SET_ADDRESS_MODE 0x20
24 #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 0x21
28 #define SSD1307FB_SET_PAGE_RANGE 0x22
29 #define SSD1307FB_CONTRAST 0x81
30 #define SSD1307FB_CHARGE_PUMP 0x8d
31 #define SSD1307FB_SEG_REMAP_ON 0xa1
32 #define SSD1307FB_DISPLAY_OFF 0xae
33 #define SSD1307FB_SET_MULTIPLEX_RATIO 0xa8
34 #define SSD1307FB_DISPLAY_ON 0xaf
35 #define SSD1307FB_START_PAGE_ADDRESS 0xb0
36 #define SSD1307FB_SET_DISPLAY_OFFSET 0xd3
37 #define SSD1307FB_SET_CLOCK_FREQ 0xd5
38 #define SSD1307FB_SET_PRECHARGE_PERIOD 0xd9
39 #define SSD1307FB_SET_COM_PINS_CONFIG 0xda
40 #define SSD1307FB_SET_VCOMH 0xdb
42 #define MAX_CONTRAST 255
46 static u_int refreshrate
= REFRESHRATE
;
47 module_param(refreshrate
, uint
, 0);
51 struct ssd1307fb_deviceinfo
{
59 struct ssd1307fb_par
{
67 struct ssd1307fb_deviceinfo
*device_info
;
68 struct i2c_client
*client
;
74 struct pwm_device
*pwm
;
82 struct ssd1307fb_array
{
87 static struct fb_fix_screeninfo ssd1307fb_fix
= {
88 .id
= "Solomon SSD1307",
89 .type
= FB_TYPE_PACKED_PIXELS
,
90 .visual
= FB_VISUAL_MONO10
,
94 .accel
= FB_ACCEL_NONE
,
97 static struct fb_var_screeninfo ssd1307fb_var
= {
101 static struct ssd1307fb_array
*ssd1307fb_alloc_array(u32 len
, u8 type
)
103 struct ssd1307fb_array
*array
;
105 array
= kzalloc(sizeof(struct ssd1307fb_array
) + len
, GFP_KERNEL
);
114 static int ssd1307fb_write_array(struct i2c_client
*client
,
115 struct ssd1307fb_array
*array
, u32 len
)
119 len
+= sizeof(struct ssd1307fb_array
);
121 ret
= i2c_master_send(client
, (u8
*)array
, len
);
123 dev_err(&client
->dev
, "Couldn't send I2C command.\n");
130 static inline int ssd1307fb_write_cmd(struct i2c_client
*client
, u8 cmd
)
132 struct ssd1307fb_array
*array
;
135 array
= ssd1307fb_alloc_array(1, SSD1307FB_COMMAND
);
139 array
->data
[0] = cmd
;
141 ret
= ssd1307fb_write_array(client
, array
, 1);
147 static void ssd1307fb_update_display(struct ssd1307fb_par
*par
)
149 struct ssd1307fb_array
*array
;
150 u8
*vmem
= par
->info
->screen_base
;
153 array
= ssd1307fb_alloc_array(par
->width
* par
->height
/ 8,
159 * The screen is divided in pages, each having a height of 8
160 * pixels, and the width of the screen. When sending a byte of
161 * data to the controller, it gives the 8 bits for the current
162 * column. I.e, the first byte are the 8 bits of the first
163 * column, then the 8 bits for the second column, etc.
166 * Representation of the screen, assuming it is 5 bits
167 * wide. Each letter-number combination is a bit that controls
179 * If you want to update this screen, you need to send 5 bytes:
180 * (1) A0 B0 C0 D0 E0 F0 G0 H0
181 * (2) A1 B1 C1 D1 E1 F1 G1 H1
182 * (3) A2 B2 C2 D2 E2 F2 G2 H2
183 * (4) A3 B3 C3 D3 E3 F3 G3 H3
184 * (5) A4 B4 C4 D4 E4 F4 G4 H4
187 for (i
= 0; i
< (par
->height
/ 8); i
++) {
188 for (j
= 0; j
< par
->width
; j
++) {
189 u32 array_idx
= i
* par
->width
+ j
;
190 array
->data
[array_idx
] = 0;
191 for (k
= 0; k
< 8; k
++) {
192 u32 page_length
= par
->width
* i
;
193 u32 index
= page_length
+ (par
->width
* k
+ j
) / 8;
194 u8 byte
= *(vmem
+ index
);
195 u8 bit
= byte
& (1 << (j
% 8));
196 bit
= bit
>> (j
% 8);
197 array
->data
[array_idx
] |= bit
<< k
;
202 ssd1307fb_write_array(par
->client
, array
, par
->width
* par
->height
/ 8);
207 static ssize_t
ssd1307fb_write(struct fb_info
*info
, const char __user
*buf
,
208 size_t count
, loff_t
*ppos
)
210 struct ssd1307fb_par
*par
= info
->par
;
211 unsigned long total_size
;
212 unsigned long p
= *ppos
;
215 total_size
= info
->fix
.smem_len
;
220 if (count
+ p
> total_size
)
221 count
= total_size
- p
;
226 dst
= (void __force
*) (info
->screen_base
+ p
);
228 if (copy_from_user(dst
, buf
, count
))
231 ssd1307fb_update_display(par
);
238 static int ssd1307fb_blank(int blank_mode
, struct fb_info
*info
)
240 struct ssd1307fb_par
*par
= info
->par
;
242 if (blank_mode
!= FB_BLANK_UNBLANK
)
243 return ssd1307fb_write_cmd(par
->client
, SSD1307FB_DISPLAY_OFF
);
245 return ssd1307fb_write_cmd(par
->client
, SSD1307FB_DISPLAY_ON
);
248 static void ssd1307fb_fillrect(struct fb_info
*info
, const struct fb_fillrect
*rect
)
250 struct ssd1307fb_par
*par
= info
->par
;
251 sys_fillrect(info
, rect
);
252 ssd1307fb_update_display(par
);
255 static void ssd1307fb_copyarea(struct fb_info
*info
, const struct fb_copyarea
*area
)
257 struct ssd1307fb_par
*par
= info
->par
;
258 sys_copyarea(info
, area
);
259 ssd1307fb_update_display(par
);
262 static void ssd1307fb_imageblit(struct fb_info
*info
, const struct fb_image
*image
)
264 struct ssd1307fb_par
*par
= info
->par
;
265 sys_imageblit(info
, image
);
266 ssd1307fb_update_display(par
);
269 static struct fb_ops ssd1307fb_ops
= {
270 .owner
= THIS_MODULE
,
271 .fb_read
= fb_sys_read
,
272 .fb_write
= ssd1307fb_write
,
273 .fb_blank
= ssd1307fb_blank
,
274 .fb_fillrect
= ssd1307fb_fillrect
,
275 .fb_copyarea
= ssd1307fb_copyarea
,
276 .fb_imageblit
= ssd1307fb_imageblit
,
279 static void ssd1307fb_deferred_io(struct fb_info
*info
,
280 struct list_head
*pagelist
)
282 ssd1307fb_update_display(info
->par
);
285 static int ssd1307fb_init(struct ssd1307fb_par
*par
)
288 u32 precharge
, dclk
, com_invdir
, compins
;
290 if (par
->device_info
->need_pwm
) {
291 par
->pwm
= pwm_get(&par
->client
->dev
, NULL
);
292 if (IS_ERR(par
->pwm
)) {
293 dev_err(&par
->client
->dev
, "Could not get PWM from device tree!\n");
294 return PTR_ERR(par
->pwm
);
297 par
->pwm_period
= pwm_get_period(par
->pwm
);
299 pwm_config(par
->pwm
, par
->pwm_period
/ 2, par
->pwm_period
);
300 pwm_enable(par
->pwm
);
302 dev_dbg(&par
->client
->dev
, "Using PWM%d with a %dns period.\n",
303 par
->pwm
->pwm
, par
->pwm_period
);
306 /* Set initial contrast */
307 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_CONTRAST
);
311 ret
= ssd1307fb_write_cmd(par
->client
, par
->contrast
);
315 /* Set segment re-map */
316 if (par
->seg_remap
) {
317 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SEG_REMAP_ON
);
322 /* Set COM direction */
323 com_invdir
= 0xc0 | (par
->com_invdir
& 0x1) << 3;
324 ret
= ssd1307fb_write_cmd(par
->client
, com_invdir
);
328 /* Set multiplex ratio value */
329 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SET_MULTIPLEX_RATIO
);
333 ret
= ssd1307fb_write_cmd(par
->client
, par
->height
- 1);
337 /* set display offset value */
338 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SET_DISPLAY_OFFSET
);
342 ret
= ssd1307fb_write_cmd(par
->client
, par
->com_offset
);
346 /* Set clock frequency */
347 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SET_CLOCK_FREQ
);
351 dclk
= ((par
->dclk_div
- 1) & 0xf) | (par
->dclk_frq
& 0xf) << 4;
352 ret
= ssd1307fb_write_cmd(par
->client
, dclk
);
356 /* Set precharge period in number of ticks from the internal clock */
357 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SET_PRECHARGE_PERIOD
);
361 precharge
= (par
->prechargep1
& 0xf) | (par
->prechargep2
& 0xf) << 4;
362 ret
= ssd1307fb_write_cmd(par
->client
, precharge
);
366 /* Set COM pins configuration */
367 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SET_COM_PINS_CONFIG
);
371 compins
= 0x02 | !(par
->com_seq
& 0x1) << 4
372 | (par
->com_lrremap
& 0x1) << 5;
373 ret
= ssd1307fb_write_cmd(par
->client
, compins
);
378 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SET_VCOMH
);
382 ret
= ssd1307fb_write_cmd(par
->client
, par
->vcomh
);
386 /* Turn on the DC-DC Charge Pump */
387 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_CHARGE_PUMP
);
391 ret
= ssd1307fb_write_cmd(par
->client
,
392 (par
->device_info
->need_chargepump
& 0x1 << 2) & 0x14);
396 /* Switch to horizontal addressing mode */
397 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SET_ADDRESS_MODE
);
401 ret
= ssd1307fb_write_cmd(par
->client
,
402 SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL
);
406 /* Set column range */
407 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SET_COL_RANGE
);
411 ret
= ssd1307fb_write_cmd(par
->client
, 0x0);
415 ret
= ssd1307fb_write_cmd(par
->client
, par
->width
- 1);
420 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SET_PAGE_RANGE
);
424 ret
= ssd1307fb_write_cmd(par
->client
, 0x0);
428 ret
= ssd1307fb_write_cmd(par
->client
,
429 par
->page_offset
+ (par
->height
/ 8) - 1);
433 /* Turn on the display */
434 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_DISPLAY_ON
);
441 static int ssd1307fb_update_bl(struct backlight_device
*bdev
)
443 struct ssd1307fb_par
*par
= bl_get_data(bdev
);
445 int brightness
= bdev
->props
.brightness
;
447 par
->contrast
= brightness
;
449 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_CONTRAST
);
452 ret
= ssd1307fb_write_cmd(par
->client
, par
->contrast
);
458 static int ssd1307fb_get_brightness(struct backlight_device
*bdev
)
460 struct ssd1307fb_par
*par
= bl_get_data(bdev
);
462 return par
->contrast
;
465 static int ssd1307fb_check_fb(struct backlight_device
*bdev
,
466 struct fb_info
*info
)
468 return (info
->bl_dev
== bdev
);
471 static const struct backlight_ops ssd1307fb_bl_ops
= {
472 .options
= BL_CORE_SUSPENDRESUME
,
473 .update_status
= ssd1307fb_update_bl
,
474 .get_brightness
= ssd1307fb_get_brightness
,
475 .check_fb
= ssd1307fb_check_fb
,
478 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1305_deviceinfo
= {
479 .default_vcomh
= 0x34,
480 .default_dclk_div
= 1,
481 .default_dclk_frq
= 7,
484 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1306_deviceinfo
= {
485 .default_vcomh
= 0x20,
486 .default_dclk_div
= 1,
487 .default_dclk_frq
= 8,
488 .need_chargepump
= 1,
491 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1307_deviceinfo
= {
492 .default_vcomh
= 0x20,
493 .default_dclk_div
= 2,
494 .default_dclk_frq
= 12,
498 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1309_deviceinfo
= {
499 .default_vcomh
= 0x34,
500 .default_dclk_div
= 1,
501 .default_dclk_frq
= 10,
504 static const struct of_device_id ssd1307fb_of_match
[] = {
506 .compatible
= "solomon,ssd1305fb-i2c",
507 .data
= (void *)&ssd1307fb_ssd1305_deviceinfo
,
510 .compatible
= "solomon,ssd1306fb-i2c",
511 .data
= (void *)&ssd1307fb_ssd1306_deviceinfo
,
514 .compatible
= "solomon,ssd1307fb-i2c",
515 .data
= (void *)&ssd1307fb_ssd1307_deviceinfo
,
518 .compatible
= "solomon,ssd1309fb-i2c",
519 .data
= (void *)&ssd1307fb_ssd1309_deviceinfo
,
523 MODULE_DEVICE_TABLE(of
, ssd1307fb_of_match
);
525 static int ssd1307fb_probe(struct i2c_client
*client
,
526 const struct i2c_device_id
*id
)
528 struct backlight_device
*bl
;
530 struct fb_info
*info
;
531 struct device_node
*node
= client
->dev
.of_node
;
532 struct fb_deferred_io
*ssd1307fb_defio
;
534 struct ssd1307fb_par
*par
;
539 dev_err(&client
->dev
, "No device tree data found!\n");
543 info
= framebuffer_alloc(sizeof(struct ssd1307fb_par
), &client
->dev
);
545 dev_err(&client
->dev
, "Couldn't allocate framebuffer.\n");
551 par
->client
= client
;
553 par
->device_info
= (struct ssd1307fb_deviceinfo
*)of_match_device(
554 ssd1307fb_of_match
, &client
->dev
)->data
;
556 par
->reset
= of_get_named_gpio(client
->dev
.of_node
,
558 if (!gpio_is_valid(par
->reset
)) {
563 if (of_property_read_u32(node
, "solomon,width", &par
->width
))
566 if (of_property_read_u32(node
, "solomon,height", &par
->height
))
569 if (of_property_read_u32(node
, "solomon,page-offset", &par
->page_offset
))
570 par
->page_offset
= 1;
572 if (of_property_read_u32(node
, "solomon,com-offset", &par
->com_offset
))
575 if (of_property_read_u32(node
, "solomon,prechargep1", &par
->prechargep1
))
576 par
->prechargep1
= 2;
578 if (of_property_read_u32(node
, "solomon,prechargep2", &par
->prechargep2
))
579 par
->prechargep2
= 2;
581 par
->seg_remap
= !of_property_read_bool(node
, "solomon,segment-no-remap");
582 par
->com_seq
= of_property_read_bool(node
, "solomon,com-seq");
583 par
->com_lrremap
= of_property_read_bool(node
, "solomon,com-lrremap");
584 par
->com_invdir
= of_property_read_bool(node
, "solomon,com-invdir");
587 par
->vcomh
= par
->device_info
->default_vcomh
;
589 /* Setup display timing */
590 par
->dclk_div
= par
->device_info
->default_dclk_div
;
591 par
->dclk_frq
= par
->device_info
->default_dclk_frq
;
593 vmem_size
= par
->width
* par
->height
/ 8;
595 vmem
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
,
596 get_order(vmem_size
));
598 dev_err(&client
->dev
, "Couldn't allocate graphical memory.\n");
603 ssd1307fb_defio
= devm_kzalloc(&client
->dev
, sizeof(struct fb_deferred_io
), GFP_KERNEL
);
604 if (!ssd1307fb_defio
) {
605 dev_err(&client
->dev
, "Couldn't allocate deferred io.\n");
610 ssd1307fb_defio
->delay
= HZ
/ refreshrate
;
611 ssd1307fb_defio
->deferred_io
= ssd1307fb_deferred_io
;
613 info
->fbops
= &ssd1307fb_ops
;
614 info
->fix
= ssd1307fb_fix
;
615 info
->fix
.line_length
= par
->width
/ 8;
616 info
->fbdefio
= ssd1307fb_defio
;
618 info
->var
= ssd1307fb_var
;
619 info
->var
.xres
= par
->width
;
620 info
->var
.xres_virtual
= par
->width
;
621 info
->var
.yres
= par
->height
;
622 info
->var
.yres_virtual
= par
->height
;
624 info
->var
.red
.length
= 1;
625 info
->var
.red
.offset
= 0;
626 info
->var
.green
.length
= 1;
627 info
->var
.green
.offset
= 0;
628 info
->var
.blue
.length
= 1;
629 info
->var
.blue
.offset
= 0;
631 info
->screen_base
= (u8 __force __iomem
*)vmem
;
632 info
->fix
.smem_start
= __pa(vmem
);
633 info
->fix
.smem_len
= vmem_size
;
635 fb_deferred_io_init(info
);
637 ret
= devm_gpio_request_one(&client
->dev
, par
->reset
,
641 dev_err(&client
->dev
,
642 "failed to request gpio %d: %d\n",
644 goto reset_oled_error
;
647 i2c_set_clientdata(client
, info
);
649 /* Reset the screen */
650 gpio_set_value(par
->reset
, 0);
652 gpio_set_value(par
->reset
, 1);
655 ret
= ssd1307fb_init(par
);
657 goto reset_oled_error
;
659 ret
= register_framebuffer(info
);
661 dev_err(&client
->dev
, "Couldn't register the framebuffer\n");
662 goto panel_init_error
;
665 snprintf(bl_name
, sizeof(bl_name
), "ssd1307fb%d", info
->node
);
666 bl
= backlight_device_register(bl_name
, &client
->dev
, par
,
667 &ssd1307fb_bl_ops
, NULL
);
670 dev_err(&client
->dev
, "unable to register backlight device: %d\n",
675 bl
->props
.brightness
= par
->contrast
;
676 bl
->props
.max_brightness
= MAX_CONTRAST
;
679 dev_info(&client
->dev
, "fb%d: %s framebuffer device registered, using %d bytes of video memory\n", info
->node
, info
->fix
.id
, vmem_size
);
684 unregister_framebuffer(info
);
686 if (par
->device_info
->need_pwm
) {
687 pwm_disable(par
->pwm
);
691 fb_deferred_io_cleanup(info
);
693 framebuffer_release(info
);
697 static int ssd1307fb_remove(struct i2c_client
*client
)
699 struct fb_info
*info
= i2c_get_clientdata(client
);
700 struct ssd1307fb_par
*par
= info
->par
;
702 ssd1307fb_write_cmd(par
->client
, SSD1307FB_DISPLAY_OFF
);
704 backlight_device_unregister(info
->bl_dev
);
706 unregister_framebuffer(info
);
707 if (par
->device_info
->need_pwm
) {
708 pwm_disable(par
->pwm
);
711 fb_deferred_io_cleanup(info
);
712 __free_pages(__va(info
->fix
.smem_start
), get_order(info
->fix
.smem_len
));
713 framebuffer_release(info
);
718 static const struct i2c_device_id ssd1307fb_i2c_id
[] = {
725 MODULE_DEVICE_TABLE(i2c
, ssd1307fb_i2c_id
);
727 static struct i2c_driver ssd1307fb_driver
= {
728 .probe
= ssd1307fb_probe
,
729 .remove
= ssd1307fb_remove
,
730 .id_table
= ssd1307fb_i2c_id
,
733 .of_match_table
= ssd1307fb_of_match
,
737 module_i2c_driver(ssd1307fb_driver
);
739 MODULE_DESCRIPTION("FB driver for the Solomon SSD1307 OLED controller");
740 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
741 MODULE_LICENSE("GPL");