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/gpio/consumer.h>
13 #include <linux/i2c.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/of_device.h>
17 #include <linux/of_gpio.h>
18 #include <linux/pwm.h>
19 #include <linux/uaccess.h>
20 #include <linux/regulator/consumer.h>
22 #define SSD1307FB_DATA 0x40
23 #define SSD1307FB_COMMAND 0x80
25 #define SSD1307FB_SET_ADDRESS_MODE 0x20
26 #define SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL (0x00)
27 #define SSD1307FB_SET_ADDRESS_MODE_VERTICAL (0x01)
28 #define SSD1307FB_SET_ADDRESS_MODE_PAGE (0x02)
29 #define SSD1307FB_SET_COL_RANGE 0x21
30 #define SSD1307FB_SET_PAGE_RANGE 0x22
31 #define SSD1307FB_CONTRAST 0x81
32 #define SSD1307FB_CHARGE_PUMP 0x8d
33 #define SSD1307FB_SEG_REMAP_ON 0xa1
34 #define SSD1307FB_DISPLAY_OFF 0xae
35 #define SSD1307FB_SET_MULTIPLEX_RATIO 0xa8
36 #define SSD1307FB_DISPLAY_ON 0xaf
37 #define SSD1307FB_START_PAGE_ADDRESS 0xb0
38 #define SSD1307FB_SET_DISPLAY_OFFSET 0xd3
39 #define SSD1307FB_SET_CLOCK_FREQ 0xd5
40 #define SSD1307FB_SET_PRECHARGE_PERIOD 0xd9
41 #define SSD1307FB_SET_COM_PINS_CONFIG 0xda
42 #define SSD1307FB_SET_VCOMH 0xdb
44 #define MAX_CONTRAST 255
48 static u_int refreshrate
= REFRESHRATE
;
49 module_param(refreshrate
, uint
, 0);
53 struct ssd1307fb_deviceinfo
{
61 struct ssd1307fb_par
{
69 const struct ssd1307fb_deviceinfo
*device_info
;
70 struct i2c_client
*client
;
76 struct pwm_device
*pwm
;
78 struct gpio_desc
*reset
;
79 struct regulator
*vbat_reg
;
85 struct ssd1307fb_array
{
90 static const struct fb_fix_screeninfo ssd1307fb_fix
= {
91 .id
= "Solomon SSD1307",
92 .type
= FB_TYPE_PACKED_PIXELS
,
93 .visual
= FB_VISUAL_MONO10
,
97 .accel
= FB_ACCEL_NONE
,
100 static const struct fb_var_screeninfo ssd1307fb_var
= {
104 static struct ssd1307fb_array
*ssd1307fb_alloc_array(u32 len
, u8 type
)
106 struct ssd1307fb_array
*array
;
108 array
= kzalloc(sizeof(struct ssd1307fb_array
) + len
, GFP_KERNEL
);
117 static int ssd1307fb_write_array(struct i2c_client
*client
,
118 struct ssd1307fb_array
*array
, u32 len
)
122 len
+= sizeof(struct ssd1307fb_array
);
124 ret
= i2c_master_send(client
, (u8
*)array
, len
);
126 dev_err(&client
->dev
, "Couldn't send I2C command.\n");
133 static inline int ssd1307fb_write_cmd(struct i2c_client
*client
, u8 cmd
)
135 struct ssd1307fb_array
*array
;
138 array
= ssd1307fb_alloc_array(1, SSD1307FB_COMMAND
);
142 array
->data
[0] = cmd
;
144 ret
= ssd1307fb_write_array(client
, array
, 1);
150 static void ssd1307fb_update_display(struct ssd1307fb_par
*par
)
152 struct ssd1307fb_array
*array
;
153 u8
*vmem
= par
->info
->screen_base
;
156 array
= ssd1307fb_alloc_array(par
->width
* par
->height
/ 8,
162 * The screen is divided in pages, each having a height of 8
163 * pixels, and the width of the screen. When sending a byte of
164 * data to the controller, it gives the 8 bits for the current
165 * column. I.e, the first byte are the 8 bits of the first
166 * column, then the 8 bits for the second column, etc.
169 * Representation of the screen, assuming it is 5 bits
170 * wide. Each letter-number combination is a bit that controls
182 * If you want to update this screen, you need to send 5 bytes:
183 * (1) A0 B0 C0 D0 E0 F0 G0 H0
184 * (2) A1 B1 C1 D1 E1 F1 G1 H1
185 * (3) A2 B2 C2 D2 E2 F2 G2 H2
186 * (4) A3 B3 C3 D3 E3 F3 G3 H3
187 * (5) A4 B4 C4 D4 E4 F4 G4 H4
190 for (i
= 0; i
< (par
->height
/ 8); i
++) {
191 for (j
= 0; j
< par
->width
; j
++) {
192 u32 array_idx
= i
* par
->width
+ j
;
193 array
->data
[array_idx
] = 0;
194 for (k
= 0; k
< 8; k
++) {
195 u32 page_length
= par
->width
* i
;
196 u32 index
= page_length
+ (par
->width
* k
+ j
) / 8;
197 u8 byte
= *(vmem
+ index
);
198 u8 bit
= byte
& (1 << (j
% 8));
199 bit
= bit
>> (j
% 8);
200 array
->data
[array_idx
] |= bit
<< k
;
205 ssd1307fb_write_array(par
->client
, array
, par
->width
* par
->height
/ 8);
210 static ssize_t
ssd1307fb_write(struct fb_info
*info
, const char __user
*buf
,
211 size_t count
, loff_t
*ppos
)
213 struct ssd1307fb_par
*par
= info
->par
;
214 unsigned long total_size
;
215 unsigned long p
= *ppos
;
218 total_size
= info
->fix
.smem_len
;
223 if (count
+ p
> total_size
)
224 count
= total_size
- p
;
229 dst
= (void __force
*) (info
->screen_base
+ p
);
231 if (copy_from_user(dst
, buf
, count
))
234 ssd1307fb_update_display(par
);
241 static int ssd1307fb_blank(int blank_mode
, struct fb_info
*info
)
243 struct ssd1307fb_par
*par
= info
->par
;
245 if (blank_mode
!= FB_BLANK_UNBLANK
)
246 return ssd1307fb_write_cmd(par
->client
, SSD1307FB_DISPLAY_OFF
);
248 return ssd1307fb_write_cmd(par
->client
, SSD1307FB_DISPLAY_ON
);
251 static void ssd1307fb_fillrect(struct fb_info
*info
, const struct fb_fillrect
*rect
)
253 struct ssd1307fb_par
*par
= info
->par
;
254 sys_fillrect(info
, rect
);
255 ssd1307fb_update_display(par
);
258 static void ssd1307fb_copyarea(struct fb_info
*info
, const struct fb_copyarea
*area
)
260 struct ssd1307fb_par
*par
= info
->par
;
261 sys_copyarea(info
, area
);
262 ssd1307fb_update_display(par
);
265 static void ssd1307fb_imageblit(struct fb_info
*info
, const struct fb_image
*image
)
267 struct ssd1307fb_par
*par
= info
->par
;
268 sys_imageblit(info
, image
);
269 ssd1307fb_update_display(par
);
272 static struct fb_ops ssd1307fb_ops
= {
273 .owner
= THIS_MODULE
,
274 .fb_read
= fb_sys_read
,
275 .fb_write
= ssd1307fb_write
,
276 .fb_blank
= ssd1307fb_blank
,
277 .fb_fillrect
= ssd1307fb_fillrect
,
278 .fb_copyarea
= ssd1307fb_copyarea
,
279 .fb_imageblit
= ssd1307fb_imageblit
,
282 static void ssd1307fb_deferred_io(struct fb_info
*info
,
283 struct list_head
*pagelist
)
285 ssd1307fb_update_display(info
->par
);
288 static int ssd1307fb_init(struct ssd1307fb_par
*par
)
291 u32 precharge
, dclk
, com_invdir
, compins
;
292 struct pwm_args pargs
;
294 if (par
->device_info
->need_pwm
) {
295 par
->pwm
= pwm_get(&par
->client
->dev
, NULL
);
296 if (IS_ERR(par
->pwm
)) {
297 dev_err(&par
->client
->dev
, "Could not get PWM from device tree!\n");
298 return PTR_ERR(par
->pwm
);
302 * FIXME: pwm_apply_args() should be removed when switching to
303 * the atomic PWM API.
305 pwm_apply_args(par
->pwm
);
307 pwm_get_args(par
->pwm
, &pargs
);
309 par
->pwm_period
= pargs
.period
;
311 pwm_config(par
->pwm
, par
->pwm_period
/ 2, par
->pwm_period
);
312 pwm_enable(par
->pwm
);
314 dev_dbg(&par
->client
->dev
, "Using PWM%d with a %dns period.\n",
315 par
->pwm
->pwm
, par
->pwm_period
);
318 /* Set initial contrast */
319 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_CONTRAST
);
323 ret
= ssd1307fb_write_cmd(par
->client
, par
->contrast
);
327 /* Set segment re-map */
328 if (par
->seg_remap
) {
329 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SEG_REMAP_ON
);
334 /* Set COM direction */
335 com_invdir
= 0xc0 | (par
->com_invdir
& 0x1) << 3;
336 ret
= ssd1307fb_write_cmd(par
->client
, com_invdir
);
340 /* Set multiplex ratio value */
341 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SET_MULTIPLEX_RATIO
);
345 ret
= ssd1307fb_write_cmd(par
->client
, par
->height
- 1);
349 /* set display offset value */
350 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SET_DISPLAY_OFFSET
);
354 ret
= ssd1307fb_write_cmd(par
->client
, par
->com_offset
);
358 /* Set clock frequency */
359 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SET_CLOCK_FREQ
);
363 dclk
= ((par
->dclk_div
- 1) & 0xf) | (par
->dclk_frq
& 0xf) << 4;
364 ret
= ssd1307fb_write_cmd(par
->client
, dclk
);
368 /* Set precharge period in number of ticks from the internal clock */
369 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SET_PRECHARGE_PERIOD
);
373 precharge
= (par
->prechargep1
& 0xf) | (par
->prechargep2
& 0xf) << 4;
374 ret
= ssd1307fb_write_cmd(par
->client
, precharge
);
378 /* Set COM pins configuration */
379 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SET_COM_PINS_CONFIG
);
383 compins
= 0x02 | !(par
->com_seq
& 0x1) << 4
384 | (par
->com_lrremap
& 0x1) << 5;
385 ret
= ssd1307fb_write_cmd(par
->client
, compins
);
390 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SET_VCOMH
);
394 ret
= ssd1307fb_write_cmd(par
->client
, par
->vcomh
);
398 /* Turn on the DC-DC Charge Pump */
399 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_CHARGE_PUMP
);
403 ret
= ssd1307fb_write_cmd(par
->client
,
404 BIT(4) | (par
->device_info
->need_chargepump
? BIT(2) : 0));
408 /* Switch to horizontal addressing mode */
409 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SET_ADDRESS_MODE
);
413 ret
= ssd1307fb_write_cmd(par
->client
,
414 SSD1307FB_SET_ADDRESS_MODE_HORIZONTAL
);
418 /* Set column range */
419 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SET_COL_RANGE
);
423 ret
= ssd1307fb_write_cmd(par
->client
, 0x0);
427 ret
= ssd1307fb_write_cmd(par
->client
, par
->width
- 1);
432 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_SET_PAGE_RANGE
);
436 ret
= ssd1307fb_write_cmd(par
->client
, 0x0);
440 ret
= ssd1307fb_write_cmd(par
->client
,
441 par
->page_offset
+ (par
->height
/ 8) - 1);
445 /* Clear the screen */
446 ssd1307fb_update_display(par
);
448 /* Turn on the display */
449 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_DISPLAY_ON
);
456 static int ssd1307fb_update_bl(struct backlight_device
*bdev
)
458 struct ssd1307fb_par
*par
= bl_get_data(bdev
);
460 int brightness
= bdev
->props
.brightness
;
462 par
->contrast
= brightness
;
464 ret
= ssd1307fb_write_cmd(par
->client
, SSD1307FB_CONTRAST
);
467 ret
= ssd1307fb_write_cmd(par
->client
, par
->contrast
);
473 static int ssd1307fb_get_brightness(struct backlight_device
*bdev
)
475 struct ssd1307fb_par
*par
= bl_get_data(bdev
);
477 return par
->contrast
;
480 static int ssd1307fb_check_fb(struct backlight_device
*bdev
,
481 struct fb_info
*info
)
483 return (info
->bl_dev
== bdev
);
486 static const struct backlight_ops ssd1307fb_bl_ops
= {
487 .options
= BL_CORE_SUSPENDRESUME
,
488 .update_status
= ssd1307fb_update_bl
,
489 .get_brightness
= ssd1307fb_get_brightness
,
490 .check_fb
= ssd1307fb_check_fb
,
493 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1305_deviceinfo
= {
494 .default_vcomh
= 0x34,
495 .default_dclk_div
= 1,
496 .default_dclk_frq
= 7,
499 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1306_deviceinfo
= {
500 .default_vcomh
= 0x20,
501 .default_dclk_div
= 1,
502 .default_dclk_frq
= 8,
503 .need_chargepump
= 1,
506 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1307_deviceinfo
= {
507 .default_vcomh
= 0x20,
508 .default_dclk_div
= 2,
509 .default_dclk_frq
= 12,
513 static struct ssd1307fb_deviceinfo ssd1307fb_ssd1309_deviceinfo
= {
514 .default_vcomh
= 0x34,
515 .default_dclk_div
= 1,
516 .default_dclk_frq
= 10,
519 static const struct of_device_id ssd1307fb_of_match
[] = {
521 .compatible
= "solomon,ssd1305fb-i2c",
522 .data
= (void *)&ssd1307fb_ssd1305_deviceinfo
,
525 .compatible
= "solomon,ssd1306fb-i2c",
526 .data
= (void *)&ssd1307fb_ssd1306_deviceinfo
,
529 .compatible
= "solomon,ssd1307fb-i2c",
530 .data
= (void *)&ssd1307fb_ssd1307_deviceinfo
,
533 .compatible
= "solomon,ssd1309fb-i2c",
534 .data
= (void *)&ssd1307fb_ssd1309_deviceinfo
,
538 MODULE_DEVICE_TABLE(of
, ssd1307fb_of_match
);
540 static int ssd1307fb_probe(struct i2c_client
*client
,
541 const struct i2c_device_id
*id
)
543 struct backlight_device
*bl
;
545 struct fb_info
*info
;
546 struct device_node
*node
= client
->dev
.of_node
;
547 struct fb_deferred_io
*ssd1307fb_defio
;
549 struct ssd1307fb_par
*par
;
554 dev_err(&client
->dev
, "No device tree data found!\n");
558 info
= framebuffer_alloc(sizeof(struct ssd1307fb_par
), &client
->dev
);
560 dev_err(&client
->dev
, "Couldn't allocate framebuffer.\n");
566 par
->client
= client
;
568 par
->device_info
= of_device_get_match_data(&client
->dev
);
570 par
->reset
= devm_gpiod_get_optional(&client
->dev
, "reset",
572 if (IS_ERR(par
->reset
)) {
573 dev_err(&client
->dev
, "failed to get reset gpio: %ld\n",
574 PTR_ERR(par
->reset
));
575 ret
= PTR_ERR(par
->reset
);
579 par
->vbat_reg
= devm_regulator_get_optional(&client
->dev
, "vbat");
580 if (IS_ERR(par
->vbat_reg
)) {
581 ret
= PTR_ERR(par
->vbat_reg
);
582 if (ret
== -ENODEV
) {
583 par
->vbat_reg
= NULL
;
585 dev_err(&client
->dev
, "failed to get VBAT regulator: %d\n",
591 if (of_property_read_u32(node
, "solomon,width", &par
->width
))
594 if (of_property_read_u32(node
, "solomon,height", &par
->height
))
597 if (of_property_read_u32(node
, "solomon,page-offset", &par
->page_offset
))
598 par
->page_offset
= 1;
600 if (of_property_read_u32(node
, "solomon,com-offset", &par
->com_offset
))
603 if (of_property_read_u32(node
, "solomon,prechargep1", &par
->prechargep1
))
604 par
->prechargep1
= 2;
606 if (of_property_read_u32(node
, "solomon,prechargep2", &par
->prechargep2
))
607 par
->prechargep2
= 2;
609 par
->seg_remap
= !of_property_read_bool(node
, "solomon,segment-no-remap");
610 par
->com_seq
= of_property_read_bool(node
, "solomon,com-seq");
611 par
->com_lrremap
= of_property_read_bool(node
, "solomon,com-lrremap");
612 par
->com_invdir
= of_property_read_bool(node
, "solomon,com-invdir");
615 par
->vcomh
= par
->device_info
->default_vcomh
;
617 /* Setup display timing */
618 par
->dclk_div
= par
->device_info
->default_dclk_div
;
619 par
->dclk_frq
= par
->device_info
->default_dclk_frq
;
621 vmem_size
= par
->width
* par
->height
/ 8;
623 vmem
= (void *)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
,
624 get_order(vmem_size
));
626 dev_err(&client
->dev
, "Couldn't allocate graphical memory.\n");
631 ssd1307fb_defio
= devm_kzalloc(&client
->dev
, sizeof(*ssd1307fb_defio
),
633 if (!ssd1307fb_defio
) {
634 dev_err(&client
->dev
, "Couldn't allocate deferred io.\n");
639 ssd1307fb_defio
->delay
= HZ
/ refreshrate
;
640 ssd1307fb_defio
->deferred_io
= ssd1307fb_deferred_io
;
642 info
->fbops
= &ssd1307fb_ops
;
643 info
->fix
= ssd1307fb_fix
;
644 info
->fix
.line_length
= par
->width
/ 8;
645 info
->fbdefio
= ssd1307fb_defio
;
647 info
->var
= ssd1307fb_var
;
648 info
->var
.xres
= par
->width
;
649 info
->var
.xres_virtual
= par
->width
;
650 info
->var
.yres
= par
->height
;
651 info
->var
.yres_virtual
= par
->height
;
653 info
->var
.red
.length
= 1;
654 info
->var
.red
.offset
= 0;
655 info
->var
.green
.length
= 1;
656 info
->var
.green
.offset
= 0;
657 info
->var
.blue
.length
= 1;
658 info
->var
.blue
.offset
= 0;
660 info
->screen_base
= (u8 __force __iomem
*)vmem
;
661 info
->fix
.smem_start
= __pa(vmem
);
662 info
->fix
.smem_len
= vmem_size
;
664 fb_deferred_io_init(info
);
666 i2c_set_clientdata(client
, info
);
669 /* Reset the screen */
670 gpiod_set_value(par
->reset
, 0);
672 gpiod_set_value(par
->reset
, 1);
677 ret
= regulator_enable(par
->vbat_reg
);
679 dev_err(&client
->dev
, "failed to enable VBAT: %d\n",
681 goto reset_oled_error
;
685 ret
= ssd1307fb_init(par
);
687 goto regulator_enable_error
;
689 ret
= register_framebuffer(info
);
691 dev_err(&client
->dev
, "Couldn't register the framebuffer\n");
692 goto panel_init_error
;
695 snprintf(bl_name
, sizeof(bl_name
), "ssd1307fb%d", info
->node
);
696 bl
= backlight_device_register(bl_name
, &client
->dev
, par
,
697 &ssd1307fb_bl_ops
, NULL
);
700 dev_err(&client
->dev
, "unable to register backlight device: %d\n",
705 bl
->props
.brightness
= par
->contrast
;
706 bl
->props
.max_brightness
= MAX_CONTRAST
;
709 dev_info(&client
->dev
, "fb%d: %s framebuffer device registered, using %d bytes of video memory\n", info
->node
, info
->fix
.id
, vmem_size
);
714 unregister_framebuffer(info
);
716 if (par
->device_info
->need_pwm
) {
717 pwm_disable(par
->pwm
);
720 regulator_enable_error
:
722 regulator_disable(par
->vbat_reg
);
724 fb_deferred_io_cleanup(info
);
726 framebuffer_release(info
);
730 static int ssd1307fb_remove(struct i2c_client
*client
)
732 struct fb_info
*info
= i2c_get_clientdata(client
);
733 struct ssd1307fb_par
*par
= info
->par
;
735 ssd1307fb_write_cmd(par
->client
, SSD1307FB_DISPLAY_OFF
);
737 backlight_device_unregister(info
->bl_dev
);
739 unregister_framebuffer(info
);
740 if (par
->device_info
->need_pwm
) {
741 pwm_disable(par
->pwm
);
744 fb_deferred_io_cleanup(info
);
745 __free_pages(__va(info
->fix
.smem_start
), get_order(info
->fix
.smem_len
));
746 framebuffer_release(info
);
751 static const struct i2c_device_id ssd1307fb_i2c_id
[] = {
758 MODULE_DEVICE_TABLE(i2c
, ssd1307fb_i2c_id
);
760 static struct i2c_driver ssd1307fb_driver
= {
761 .probe
= ssd1307fb_probe
,
762 .remove
= ssd1307fb_remove
,
763 .id_table
= ssd1307fb_i2c_id
,
766 .of_match_table
= ssd1307fb_of_match
,
770 module_i2c_driver(ssd1307fb_driver
);
772 MODULE_DESCRIPTION("FB driver for the Solomon SSD1307 OLED controller");
773 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
774 MODULE_LICENSE("GPL");