Reported by Nikolaus Schaller, Aug 9, 2016

we have merged a driver and it is configured / probed.

But reading the crtouch device returns:

root@letux:/sys/class/crtouch_dev/crtouch_dev# cat /dev/crtouch_dev
[  279.277457] Unhandled fault: page domain fault (0x01b) at 
0xb6e33000
[  279.284161] pgd = eb6f4000
[  279.287025] [b6e33000] *pgd=ab677835, *pte=afff979f, 
*ppte=afff9e7f
[  279.293681] Internal error: : 1b [#1] PREEMPT SMP ARM
[  279.299001] Modules linked in: usbserial cdc_ether usbnet cdc_acm 
bnep bluetooth autofs4 usb_f_ecm g_ether usb_f_rndis u_ether 
libcomposite configfs ipv6 arc4 wl18xx wlcore mac80211 cfg80211 
snd_soc_omap_hdmi_audio panel_boe_w677l omapdrm dwc3 drm_kms_helper 
cfbfillrect syscopyarea cfbimgblt sysfillrect sysimgblt fb_sys_fops 
cfbcopyarea drm encoder_tpd12s015 connector_hdmi w2cbw003_bluetooth 
snd_soc_omap_abe_twl6040 snd_soc_twl6040 wwan_on_off 
pwm_omap_dmtimer leds_gpio omapdss pwm_bl wlcore_sdio ehci_omap 
dwc3_omap snd_soc_ts3a225e leds_is31fl319x crtouch_mt tsc2007 
bq27xxx_battery_i2c bq2429x_charger leds_tca6507 twl6040_vibra 
gpio_twl6040 ina2xx bq27xxx_battery palmas_gpadc palmas_pwrbutton 
as5013 bma150 tca8418_keypad bmg160_i2c usb3503 bmg160_core 
input_polldev bno055 snd_soc_omap_mcpdm snd_soc_omap_mcbsp 
snd_soc_omap snd_pcm_dmaengine
[  279.378264] CPU: 0 PID: 2833 Comm: cat Tainted: G        W       
4.8.0-rc1-letux+ #661
[  279.386606] Hardware name: Generic OMAP5 (Flattened Device Tree)
[  279.392930] task: eda98e40 task.stack: eb16e000
[  279.397719] PC is at crtouch_read+0x10/0xfc [crtouch_mt]
[  279.403325] LR is at __vfs_read+0x20/0x104
[  279.407642] pc : [<bf089240>]    lr : [<c0252af0>]    
psr: a00f0013
[  279.407642] sp : eb16fee8  ip : bf08b248  fp : 00020000
[  279.419727] r10: 00000000  r9 : eb16e000  r8 : c0107204
[  279.425233] r7 : eb16ff88  r6 : b6e33000  r5 : eb0275c0  r4 : 
b6e33000
[  279.432109] r3 : eb16ff88  r2 : 00020000  r1 : b6e33000  r0 : 
eb0275c0
[  279.438991] Flags: NzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  
Segment none
[  279.446504] Control: 10c5387d  Table: ab6f406a  DAC: 00000051
[  279.452553] Process cat (pid: 2833, stack limit = 0xeb16e218)
[  279.458605] Stack: (0xeb16fee8 to 0xeb170000)
[  279.463204] fee0:                   eb0275c0 b6e33000 bf089230 
eb0275c0 b6e33000 c0252af0
[  279.471820] ff00: b6f40510 00000001 00004201 c0101310 00000000 
00000000 600f0013 eb0275c0
[  279.480432] ff20: 00020000 eb0275c8 eca4ad80 c0107204 eb16e000 
00000000 00020000 c03bc468
[  279.489051] ff40: 00000000 00000000 00000000 00020000 eb0275c0 
b6e33000 eb16ff88 c0253830
[  279.497663] ff60: eb0275c0 b6e33000 00020000 eb0275c0 eb0275c0 
00020000 b6e33000 c0107204
[  279.506270] ff80: eb16e000 c0254484 00000000 00000000 00020000 
00020000 00020000 b6e33000
[  279.514898] ffa0: 00000003 c0107060 00020000 00020000 00000003 
b6e33000 00020000 000271c4
[  279.523517] ffc0: 00020000 00020000 b6e33000 00000003 7fffe000 
00000000 00000000 00020000
[  279.532136] ffe0: 00000000 bed22b64 00013835 b6edefa6 400f0030 
00000003 00000000 00000000
[  279.540795] [<bf089240>] (crtouch_read [crtouch_mt]) from 
[<c0252af0>] (__vfs_read+0x20/0x104)
[  279.549887] [<c0252af0>] (__vfs_read) from 
[<c0253830>] (vfs_read+0x94/0x100)
[  279.557416] [<c0253830>] (vfs_read) from [<c0254484>] 
(SyS_read+0x40/0x80)
[  279.564667] [<c0254484>] (SyS_read) from [<c0107060>] 
(ret_fast_syscall+0x0/0x1c)
[  279.572558] Code: e92d4073 e3510000 0a000021 e1a04001 (e5d11000) 
[  279.578988] ---[ end trace 95914bcb3c926ea7 ]---

Message from syslogd@localhost at Jan  1 01:02:40 ...
 kernel:[  279.293681] Internal error: : 1b [#1] PREEMPT SMP ARM

Message from syslogd@localhost at Jan  1 01:02:40 ...
 kernel:[  279.452553] Process cat (pid: 2833, stack limit = 
0xeb16e218)

Message from syslogd@localhost at Jan  1 01:02:40 ...
 kernel:[  279.458605] Stack: (0xeb16fee8 to 0xeb170000)

Message from syslogd@localhost at Jan  1 01:02:40 ...
 kernel:[  279.463204] fee0:                   eb0275c0 b6e33000 
bf089230 eb0275c0 b6e33000 c0252af0

Message from syslogd@localhost at Jan  1 01:02:40 ...
 kernel:[  279.471820] ff00: b6f40510 00000001 00004201 c0101310 
00000000 00000000 600f0013 eb0275c0

Message from syslogd@localhost at Jan  1 01:02:40 ...
 kernel:[  279.480432] ff20: 00020000 eb0275c8 eca4ad80 c0107204 
eb16e000 00000000 00020000 c03bc468

Message from syslogd@localhost at Jan  1 01:02:40 ...
 kernel:[  279.489051] ff40: 00000000 00000000 00000000 00020000 
eb0275c0 b6e33000 eb16ff88 c0253830

Message from syslogd@localhost at Jan  1 01:02:40 ...
 kernel:[  279.497663] ff60: eb0275c0 b6e33000 00020000 eb0275c0 
eb0275c0 00020000 b6e33000 c0107204

Message from syslogd@localhost at Jan  1 01:02:40 ...
 kernel:[  279.506270] ff80: eb16e000 c0254484 00000000 00000000 
00020000 00020000 00020000 b6e33000

Message from syslogd@localhost at Jan  1 01:02:40 ...
 kernel:[  279.514898] ffa0: 00000003 c0107060 00020000 00020000 
00000003 b6e33000 00020000 000271c4

Message from syslogd@localhost at Jan  1 01:02:40 ...
 kernel:[  279.523517] ffc0: 00020000 00020000 b6e33000 00000003 
7fffe000 00000000 00000000 00020000

Message from syslogd@localhost at Jan  1 01:02:40 ...
 kernel:[  279.532136] ffe0: 00000000 bed22b64 00013835 b6edefa6 
400f0030 00000003 00000000 00000000

Message from syslogd@localhost at Jan  1 01:02:40 ...
 kernel:[  279.572558] Code: e92d4073 e3510000 0a000021 e1a04001 
(e5d11000) 
Segmentation fault
root@letux:/sys/class/crtouch_dev/crtouch_dev# 

And what we would need is an /dev/input/event driver.