2 * Mainly by David Woodhouse, somewhat modified by Jordan Crouse
4 * Copyright © 2006-2007 Red Hat, Inc.
5 * Copyright © 2006-2007 Advanced Micro Devices, Inc.
6 * Copyright © 2009 VIA Technology, Inc.
7 * Copyright (c) 2010-2011 Andres Salomon <dilinger@queued.net>
9 * This program is free software. You can redistribute it and/or
10 * modify it under the terms of version 2 of the GNU General Public
11 * License as published by the Free Software Foundation.
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
16 #include <linux/kernel.h>
18 #include <linux/console.h>
19 #include <linux/i2c.h>
20 #include <linux/platform_device.h>
21 #include <linux/pci.h>
22 #include <linux/pci_ids.h>
23 #include <linux/interrupt.h>
24 #include <linux/delay.h>
25 #include <linux/module.h>
26 #include <linux/backlight.h>
27 #include <linux/device.h>
28 #include <linux/uaccess.h>
29 #include <linux/ctype.h>
30 #include <linux/reboot.h>
31 #include <linux/olpc-ec.h>
35 #include "olpc_dcon.h"
37 /* Module definitions */
39 static ushort resumeline
= 898;
40 module_param(resumeline
, ushort
, 0444);
42 /* Default off since it doesn't work on DCON ASIC in B-test OLPC board */
44 module_param(useaa
, int, 0444);
46 static struct dcon_platform_data
*pdata
;
50 /* Platform devices */
51 static struct platform_device
*dcon_device
;
53 static DECLARE_WAIT_QUEUE_HEAD(dcon_wait_queue
);
55 static unsigned short normal_i2c
[] = { 0x0d, I2C_CLIENT_END
};
57 static s32
dcon_write(struct dcon_priv
*dcon
, u8 reg
, u16 val
)
59 return i2c_smbus_write_word_data(dcon
->client
, reg
, val
);
62 static s32
dcon_read(struct dcon_priv
*dcon
, u8 reg
)
64 return i2c_smbus_read_word_data(dcon
->client
, reg
);
67 /* ===== API functions - these are called by a variety of users ==== */
69 static int dcon_hw_init(struct dcon_priv
*dcon
, int is_init
)
74 ver
= dcon_read(dcon
, DCON_REG_ID
);
75 if ((ver
>> 8) != 0xDC) {
76 pr_err("DCON ID not 0xDCxx: 0x%04x instead.\n", ver
);
82 pr_info("Discovered DCON version %x\n", ver
& 0xFF);
83 rc
= pdata
->init(dcon
);
85 pr_err("Unable to init.\n");
91 dev_err(&dcon
->client
->dev
,
92 "DCON v1 is unsupported, giving up..\n");
97 /* SDRAM setup/hold time */
98 dcon_write(dcon
, 0x3a, 0xc040);
99 dcon_write(dcon
, 0x41, 0x0000);
100 dcon_write(dcon
, 0x41, 0x0101);
101 dcon_write(dcon
, 0x42, 0x0101);
103 /* Colour swizzle, AA, no passthrough, backlight */
105 dcon
->disp_mode
= MODE_PASSTHRU
| MODE_BL_ENABLE
|
108 dcon
->disp_mode
|= MODE_COL_AA
;
110 dcon_write(dcon
, DCON_REG_MODE
, dcon
->disp_mode
);
113 /* Set the scanline to interrupt on during resume */
114 dcon_write(dcon
, DCON_REG_SCAN_INT
, resumeline
);
121 * The smbus doesn't always come back due to what is believed to be
122 * hardware (power rail) bugs. For older models where this is known to
123 * occur, our solution is to attempt to wait for the bus to stabilize;
124 * if it doesn't happen, cut power to the dcon, repower it, and wait
125 * for the bus to stabilize. Rinse, repeat until we have a working
126 * smbus. For newer models, we simply BUG(); we want to know if this
127 * still happens despite the power fixes that have been made!
129 static int dcon_bus_stabilize(struct dcon_priv
*dcon
, int is_powered_down
)
131 unsigned long timeout
;
135 if (is_powered_down
) {
137 x
= olpc_ec_cmd(0x26, (unsigned char *)&x
, 1, NULL
, 0);
139 pr_warn("unable to force dcon to power up: %d!\n", x
);
142 msleep(10); /* we'll be conservative */
145 pdata
->bus_stabilize_wiggle();
147 for (x
= -1, timeout
= 50; timeout
&& x
< 0; timeout
--) {
149 x
= dcon_read(dcon
, DCON_REG_ID
);
152 pr_err("unable to stabilize dcon's smbus, reasserting power and praying.\n");
153 BUG_ON(olpc_board_at_least(olpc_board(0xc2)));
155 olpc_ec_cmd(0x26, (unsigned char *)&x
, 1, NULL
, 0);
158 goto power_up
; /* argh, stupid hardware.. */
162 return dcon_hw_init(dcon
, 0);
166 static void dcon_set_backlight(struct dcon_priv
*dcon
, u8 level
)
168 dcon
->bl_val
= level
;
169 dcon_write(dcon
, DCON_REG_BRIGHT
, dcon
->bl_val
);
171 /* Purposely turn off the backlight when we go to level 0 */
172 if (dcon
->bl_val
== 0) {
173 dcon
->disp_mode
&= ~MODE_BL_ENABLE
;
174 dcon_write(dcon
, DCON_REG_MODE
, dcon
->disp_mode
);
175 } else if (!(dcon
->disp_mode
& MODE_BL_ENABLE
)) {
176 dcon
->disp_mode
|= MODE_BL_ENABLE
;
177 dcon_write(dcon
, DCON_REG_MODE
, dcon
->disp_mode
);
181 /* Set the output type to either color or mono */
182 static int dcon_set_mono_mode(struct dcon_priv
*dcon
, bool enable_mono
)
184 if (dcon
->mono
== enable_mono
)
187 dcon
->mono
= enable_mono
;
190 dcon
->disp_mode
&= ~(MODE_CSWIZZLE
| MODE_COL_AA
);
191 dcon
->disp_mode
|= MODE_MONO_LUMA
;
193 dcon
->disp_mode
&= ~(MODE_MONO_LUMA
);
194 dcon
->disp_mode
|= MODE_CSWIZZLE
;
196 dcon
->disp_mode
|= MODE_COL_AA
;
199 dcon_write(dcon
, DCON_REG_MODE
, dcon
->disp_mode
);
203 /* For now, this will be really stupid - we need to address how
204 * DCONLOAD works in a sleep and account for it accordingly
207 static void dcon_sleep(struct dcon_priv
*dcon
, bool sleep
)
211 /* Turn off the backlight and put the DCON to sleep */
213 if (dcon
->asleep
== sleep
)
216 if (!olpc_board_at_least(olpc_board(0xc2)))
221 x
= olpc_ec_cmd(0x26, (unsigned char *)&x
, 1, NULL
, 0);
223 pr_warn("unable to force dcon to power down: %d!\n", x
);
225 dcon
->asleep
= sleep
;
227 /* Only re-enable the backlight if the backlight value is set */
228 if (dcon
->bl_val
!= 0)
229 dcon
->disp_mode
|= MODE_BL_ENABLE
;
230 x
= dcon_bus_stabilize(dcon
, 1);
232 pr_warn("unable to reinit dcon hardware: %d!\n", x
);
234 dcon
->asleep
= sleep
;
236 /* Restore backlight */
237 dcon_set_backlight(dcon
, dcon
->bl_val
);
240 /* We should turn off some stuff in the framebuffer - but what? */
243 /* the DCON seems to get confused if we change DCONLOAD too
244 * frequently -- i.e., approximately faster than frame time.
245 * normally we don't change it this fast, so in general we won't
248 static void dcon_load_holdoff(struct dcon_priv
*dcon
)
250 struct timespec delta_t
, now
;
252 getnstimeofday(&now
);
253 delta_t
= timespec_sub(now
, dcon
->load_time
);
254 if (delta_t
.tv_sec
!= 0 ||
255 delta_t
.tv_nsec
> NSEC_PER_MSEC
* 20) {
262 static bool dcon_blank_fb(struct dcon_priv
*dcon
, bool blank
)
266 if (!lock_fb_info(dcon
->fbinfo
)) {
267 dev_err(&dcon
->client
->dev
, "unable to lock framebuffer\n");
271 dcon
->ignore_fb_events
= true;
272 err
= fb_blank(dcon
->fbinfo
,
273 blank
? FB_BLANK_POWERDOWN
: FB_BLANK_UNBLANK
);
274 dcon
->ignore_fb_events
= false;
276 unlock_fb_info(dcon
->fbinfo
);
279 dev_err(&dcon
->client
->dev
, "couldn't %sblank framebuffer\n",
286 /* Set the source of the display (CPU or DCON) */
287 static void dcon_source_switch(struct work_struct
*work
)
289 struct dcon_priv
*dcon
= container_of(work
, struct dcon_priv
,
291 DECLARE_WAITQUEUE(wait
, current
);
292 int source
= dcon
->pending_src
;
294 if (dcon
->curr_src
== source
)
297 dcon_load_holdoff(dcon
);
299 dcon
->switched
= false;
302 case DCON_SOURCE_CPU
:
303 pr_info("dcon_source_switch to CPU\n");
304 /* Enable the scanline interrupt bit */
305 if (dcon_write(dcon
, DCON_REG_MODE
,
306 dcon
->disp_mode
| MODE_SCAN_INT
))
307 pr_err("couldn't enable scanline interrupt!\n");
309 /* Wait up to one second for the scanline interrupt */
310 wait_event_timeout(dcon_wait_queue
,
311 dcon
->switched
== true, HZ
);
315 pr_err("Timeout entering CPU mode; expect a screen glitch.\n");
317 /* Turn off the scanline interrupt */
318 if (dcon_write(dcon
, DCON_REG_MODE
, dcon
->disp_mode
))
319 pr_err("couldn't disable scanline interrupt!\n");
322 * Ideally we'd like to disable interrupts here so that the
323 * fb unblanking and DCON turn on happen at a known time value;
324 * however, we can't do that right now with fb_blank
325 * messing with semaphores.
327 * For now, we just hope..
329 if (!dcon_blank_fb(dcon
, false)) {
330 pr_err("Failed to enter CPU mode\n");
331 dcon
->pending_src
= DCON_SOURCE_DCON
;
335 /* And turn off the DCON */
336 pdata
->set_dconload(1);
337 getnstimeofday(&dcon
->load_time
);
339 pr_info("The CPU has control\n");
341 case DCON_SOURCE_DCON
:
344 struct timespec delta_t
;
346 pr_info("dcon_source_switch to DCON\n");
348 add_wait_queue(&dcon_wait_queue
, &wait
);
349 set_current_state(TASK_UNINTERRUPTIBLE
);
351 /* Clear DCONLOAD - this implies that the DCON is in control */
352 pdata
->set_dconload(0);
353 getnstimeofday(&dcon
->load_time
);
355 t
= schedule_timeout(HZ
/2);
356 remove_wait_queue(&dcon_wait_queue
, &wait
);
357 set_current_state(TASK_RUNNING
);
359 if (!dcon
->switched
) {
360 pr_err("Timeout entering DCON mode; expect a screen glitch.\n");
362 /* sometimes the DCON doesn't follow its own rules,
363 * and doesn't wait for two vsync pulses before
364 * ack'ing the frame load with an IRQ. the result
365 * is that the display shows the *previously*
366 * loaded frame. we can detect this by looking at
367 * the time between asserting DCONLOAD and the IRQ --
368 * if it's less than 20msec, then the DCON couldn't
369 * have seen two VSYNC pulses. in that case we
370 * deassert and reassert, and hope for the best.
371 * see http://dev.laptop.org/ticket/9664
373 delta_t
= timespec_sub(dcon
->irq_time
, dcon
->load_time
);
374 if (dcon
->switched
&& delta_t
.tv_sec
== 0 &&
375 delta_t
.tv_nsec
< NSEC_PER_MSEC
* 20) {
376 pr_err("missed loading, retrying\n");
377 pdata
->set_dconload(1);
379 pdata
->set_dconload(0);
380 getnstimeofday(&dcon
->load_time
);
385 dcon_blank_fb(dcon
, true);
386 pr_info("The DCON has control\n");
393 dcon
->curr_src
= source
;
396 static void dcon_set_source(struct dcon_priv
*dcon
, int arg
)
398 if (dcon
->pending_src
== arg
)
401 dcon
->pending_src
= arg
;
403 if ((dcon
->curr_src
!= arg
) && !work_pending(&dcon
->switch_source
))
404 schedule_work(&dcon
->switch_source
);
407 static void dcon_set_source_sync(struct dcon_priv
*dcon
, int arg
)
409 dcon_set_source(dcon
, arg
);
410 flush_scheduled_work();
413 static ssize_t
dcon_mode_show(struct device
*dev
,
414 struct device_attribute
*attr
, char *buf
)
416 struct dcon_priv
*dcon
= dev_get_drvdata(dev
);
417 return sprintf(buf
, "%4.4X\n", dcon
->disp_mode
);
420 static ssize_t
dcon_sleep_show(struct device
*dev
,
421 struct device_attribute
*attr
, char *buf
)
424 struct dcon_priv
*dcon
= dev_get_drvdata(dev
);
425 return sprintf(buf
, "%d\n", dcon
->asleep
);
428 static ssize_t
dcon_freeze_show(struct device
*dev
,
429 struct device_attribute
*attr
, char *buf
)
431 struct dcon_priv
*dcon
= dev_get_drvdata(dev
);
432 return sprintf(buf
, "%d\n", dcon
->curr_src
== DCON_SOURCE_DCON
? 1 : 0);
435 static ssize_t
dcon_mono_show(struct device
*dev
,
436 struct device_attribute
*attr
, char *buf
)
438 struct dcon_priv
*dcon
= dev_get_drvdata(dev
);
439 return sprintf(buf
, "%d\n", dcon
->mono
);
442 static ssize_t
dcon_resumeline_show(struct device
*dev
,
443 struct device_attribute
*attr
, char *buf
)
445 return sprintf(buf
, "%d\n", resumeline
);
448 static ssize_t
dcon_mono_store(struct device
*dev
,
449 struct device_attribute
*attr
, const char *buf
, size_t count
)
451 unsigned long enable_mono
;
454 rc
= kstrtoul(buf
, 10, &enable_mono
);
458 dcon_set_mono_mode(dev_get_drvdata(dev
), enable_mono
? true : false);
463 static ssize_t
dcon_freeze_store(struct device
*dev
,
464 struct device_attribute
*attr
, const char *buf
, size_t count
)
466 struct dcon_priv
*dcon
= dev_get_drvdata(dev
);
467 unsigned long output
;
470 ret
= kstrtoul(buf
, 10, &output
);
474 pr_info("dcon_freeze_store: %lu\n", output
);
478 dcon_set_source(dcon
, DCON_SOURCE_CPU
);
481 dcon_set_source_sync(dcon
, DCON_SOURCE_DCON
);
483 case 2: /* normally unused */
484 dcon_set_source(dcon
, DCON_SOURCE_DCON
);
493 static ssize_t
dcon_resumeline_store(struct device
*dev
,
494 struct device_attribute
*attr
, const char *buf
, size_t count
)
499 rc
= kstrtou16(buf
, 10, &rl
);
504 dcon_write(dev_get_drvdata(dev
), DCON_REG_SCAN_INT
, resumeline
);
509 static ssize_t
dcon_sleep_store(struct device
*dev
,
510 struct device_attribute
*attr
, const char *buf
, size_t count
)
512 unsigned long output
;
515 ret
= kstrtoul(buf
, 10, &output
);
519 dcon_sleep(dev_get_drvdata(dev
), output
? true : false);
523 static struct device_attribute dcon_device_files
[] = {
524 __ATTR(mode
, 0444, dcon_mode_show
, NULL
),
525 __ATTR(sleep
, 0644, dcon_sleep_show
, dcon_sleep_store
),
526 __ATTR(freeze
, 0644, dcon_freeze_show
, dcon_freeze_store
),
527 __ATTR(monochrome
, 0644, dcon_mono_show
, dcon_mono_store
),
528 __ATTR(resumeline
, 0644, dcon_resumeline_show
, dcon_resumeline_store
),
531 static int dcon_bl_update(struct backlight_device
*dev
)
533 struct dcon_priv
*dcon
= bl_get_data(dev
);
534 u8 level
= dev
->props
.brightness
& 0x0F;
536 if (dev
->props
.power
!= FB_BLANK_UNBLANK
)
539 if (level
!= dcon
->bl_val
)
540 dcon_set_backlight(dcon
, level
);
545 static int dcon_bl_get(struct backlight_device
*dev
)
547 struct dcon_priv
*dcon
= bl_get_data(dev
);
551 static const struct backlight_ops dcon_bl_ops
= {
552 .update_status
= dcon_bl_update
,
553 .get_brightness
= dcon_bl_get
,
556 static struct backlight_properties dcon_bl_props
= {
557 .max_brightness
= 15,
558 .type
= BACKLIGHT_RAW
,
559 .power
= FB_BLANK_UNBLANK
,
562 static int dcon_reboot_notify(struct notifier_block
*nb
,
563 unsigned long foo
, void *bar
)
565 struct dcon_priv
*dcon
= container_of(nb
, struct dcon_priv
, reboot_nb
);
567 if (!dcon
|| !dcon
->client
)
570 /* Turn off the DCON. Entirely. */
571 dcon_write(dcon
, DCON_REG_MODE
, 0x39);
572 dcon_write(dcon
, DCON_REG_MODE
, 0x32);
576 static int unfreeze_on_panic(struct notifier_block
*nb
,
577 unsigned long e
, void *p
)
579 pdata
->set_dconload(1);
583 static struct notifier_block dcon_panic_nb
= {
584 .notifier_call
= unfreeze_on_panic
,
588 * When the framebuffer sleeps due to external sources (e.g. user idle), power
589 * down the DCON as well. Power it back up when the fb comes back to life.
591 static int dcon_fb_notifier(struct notifier_block
*self
,
592 unsigned long event
, void *data
)
594 struct fb_event
*evdata
= data
;
595 struct dcon_priv
*dcon
= container_of(self
, struct dcon_priv
,
597 int *blank
= (int *)evdata
->data
;
598 if (((event
!= FB_EVENT_BLANK
) && (event
!= FB_EVENT_CONBLANK
)) ||
599 dcon
->ignore_fb_events
)
601 dcon_sleep(dcon
, *blank
? true : false);
605 static int dcon_detect(struct i2c_client
*client
, struct i2c_board_info
*info
)
607 strlcpy(info
->type
, "olpc_dcon", I2C_NAME_SIZE
);
612 static int dcon_probe(struct i2c_client
*client
, const struct i2c_device_id
*id
)
614 struct dcon_priv
*dcon
;
620 dcon
= kzalloc(sizeof(*dcon
), GFP_KERNEL
);
624 dcon
->client
= client
;
625 INIT_WORK(&dcon
->switch_source
, dcon_source_switch
);
626 dcon
->reboot_nb
.notifier_call
= dcon_reboot_notify
;
627 dcon
->reboot_nb
.priority
= -1;
628 dcon
->fbevent_nb
.notifier_call
= dcon_fb_notifier
;
630 i2c_set_clientdata(client
, dcon
);
632 if (num_registered_fb
< 1) {
633 dev_err(&client
->dev
, "DCON driver requires a registered fb\n");
637 dcon
->fbinfo
= registered_fb
[0];
639 rc
= dcon_hw_init(dcon
, 1);
643 /* Add the DCON device */
645 dcon_device
= platform_device_alloc("dcon", -1);
647 if (dcon_device
== NULL
) {
648 pr_err("Unable to create the DCON device\n");
652 rc
= platform_device_add(dcon_device
);
653 platform_set_drvdata(dcon_device
, dcon
);
656 pr_err("Unable to add the DCON device\n");
660 for (i
= 0; i
< ARRAY_SIZE(dcon_device_files
); i
++) {
661 rc
= device_create_file(&dcon_device
->dev
,
662 &dcon_device_files
[i
]);
664 dev_err(&dcon_device
->dev
, "Cannot create sysfs file\n");
669 dcon
->bl_val
= dcon_read(dcon
, DCON_REG_BRIGHT
) & 0x0F;
671 /* Add the backlight device for the DCON */
672 dcon_bl_props
.brightness
= dcon
->bl_val
;
673 dcon
->bl_dev
= backlight_device_register("dcon-bl", &dcon_device
->dev
,
674 dcon
, &dcon_bl_ops
, &dcon_bl_props
);
675 if (IS_ERR(dcon
->bl_dev
)) {
676 dev_err(&client
->dev
, "cannot register backlight dev (%ld)\n",
677 PTR_ERR(dcon
->bl_dev
));
681 register_reboot_notifier(&dcon
->reboot_nb
);
682 atomic_notifier_chain_register(&panic_notifier_list
, &dcon_panic_nb
);
683 fb_register_client(&dcon
->fbevent_nb
);
688 for (j
= 0; j
< i
; j
++)
689 device_remove_file(&dcon_device
->dev
, &dcon_device_files
[j
]);
691 platform_device_unregister(dcon_device
);
694 free_irq(DCON_IRQ
, dcon
);
700 static int dcon_remove(struct i2c_client
*client
)
702 struct dcon_priv
*dcon
= i2c_get_clientdata(client
);
704 fb_unregister_client(&dcon
->fbevent_nb
);
705 unregister_reboot_notifier(&dcon
->reboot_nb
);
706 atomic_notifier_chain_unregister(&panic_notifier_list
, &dcon_panic_nb
);
708 free_irq(DCON_IRQ
, dcon
);
711 backlight_device_unregister(dcon
->bl_dev
);
713 if (dcon_device
!= NULL
)
714 platform_device_unregister(dcon_device
);
715 cancel_work_sync(&dcon
->switch_source
);
723 static int dcon_suspend(struct i2c_client
*client
, pm_message_t state
)
725 struct dcon_priv
*dcon
= i2c_get_clientdata(client
);
728 /* Set up the DCON to have the source */
729 dcon_set_source_sync(dcon
, DCON_SOURCE_DCON
);
735 static int dcon_resume(struct i2c_client
*client
)
737 struct dcon_priv
*dcon
= i2c_get_clientdata(client
);
740 dcon_bus_stabilize(dcon
, 0);
741 dcon_set_source(dcon
, DCON_SOURCE_CPU
);
750 irqreturn_t
dcon_interrupt(int irq
, void *id
)
752 struct dcon_priv
*dcon
= id
;
755 if (pdata
->read_status(&status
))
758 switch (status
& 3) {
760 pr_debug("DCONLOAD_MISSED interrupt\n");
763 case 2: /* switch to DCON mode */
764 case 1: /* switch to CPU mode */
765 dcon
->switched
= true;
766 getnstimeofday(&dcon
->irq_time
);
767 wake_up(&dcon_wait_queue
);
771 /* workaround resume case: the DCON (on 1.5) doesn't
772 * ever assert status 0x01 when switching to CPU mode
773 * during resume. this is because DCONLOAD is de-asserted
774 * _immediately_ upon exiting S3, so the actual release
775 * of the DCON happened long before this point.
776 * see http://dev.laptop.org/ticket/9869
778 if (dcon
->curr_src
!= dcon
->pending_src
&& !dcon
->switched
) {
779 dcon
->switched
= true;
780 getnstimeofday(&dcon
->irq_time
);
781 wake_up(&dcon_wait_queue
);
782 pr_debug("switching w/ status 0/0\n");
784 pr_debug("scanline interrupt w/CPU\n");
791 static const struct i2c_device_id dcon_idtable
[] = {
796 MODULE_DEVICE_TABLE(i2c
, dcon_idtable
);
798 struct i2c_driver dcon_driver
= {
802 .class = I2C_CLASS_DDC
| I2C_CLASS_HWMON
,
803 .id_table
= dcon_idtable
,
805 .remove
= __devexit_p(dcon_remove
),
806 .detect
= dcon_detect
,
807 .address_list
= normal_i2c
,
809 .suspend
= dcon_suspend
,
810 .resume
= dcon_resume
,
814 static int __init
olpc_dcon_init(void)
816 #ifdef CONFIG_FB_OLPC_DCON_1_5
818 if (olpc_board_at_least(olpc_board(0xd0)))
819 pdata
= &dcon_pdata_xo_1_5
;
821 #ifdef CONFIG_FB_OLPC_DCON_1
823 pdata
= &dcon_pdata_xo_1
;
826 return i2c_add_driver(&dcon_driver
);
829 static void __exit
olpc_dcon_exit(void)
831 i2c_del_driver(&dcon_driver
);
834 module_init(olpc_dcon_init
);
835 module_exit(olpc_dcon_exit
);
837 MODULE_LICENSE("GPL");