Tool/software: Linux
I need to disable kernel access to the am3358 rtc hardware.
I have already disabled accesses in u-boot but not the kernel.
using this version of linux:
git://git.ti.com/ti-linux-kernel/ti-linux-kernel.git
v4.9.69-2821-g89d085d
I have added this to device tree:
&rtc {
status = "disabled";
ti,hwmods = "disabled";
};
I assume this is wrong because:
[ 0.267191] platform 44e3e000.rtc: Cannot lookup hwmod 'rtc' [ 0.270698] No ATAGs?
I have added this patch to not write to the rtc clock:
diff --git a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
index 62672e7..dee0100 100644
--- a/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
+++ b/arch/arm/mach-omap2/omap_hwmod_33xx_data.c
@@ -525,7 +525,6 @@
&am33xx_l4_wkup__smartreflex1,
&am33xx_l4_wkup__uart1,
&am33xx_l4_wkup__timer1,
- &am33xx_l4_wkup__rtc,
&am33xx_l4_wkup__i2c1,
&am33xx_l4_wkup__gpio0,
&am33xx_l4_wkup__adc_tsc,
what is required to disable rtc?
error accessing rtc:
[ 10.984754] omap_rtc 44e3e000.rtc: _od_fail_runtime_resume: FIXME: missing hwmod/omap_dev info [ 10.993704] Unhandled fault: external abort on non-linefetch (0x1028) at 0xf9e3e054 [ 11.001393] pgd = d1154000 [ 11.004109] [f9e3e054] *pgd=44e11452(bad) [ 11.008155] Internal error: : 1028 [#1] PREEMPT ARM [ 11.013051] Modules linked in: rtc_omap(+) musb_am335x(+) omap_wdt sch_fq_codel [ 11.020430] CPU: 0 PID: 154 Comm: systemd-udevd Not tainted 4.9.69-g89d085d1a4 #6 [ 11.027944] Hardware name: Generic AM33XX (Flattened Device Tree) [ 11.034062] task: d468b700 task.stack: d1150000 [ 11.038639] PC is at omap_rtc_probe+0x3d0/0x4e8 [rtc_omap] [ 11.044153] LR is at omap_rtc_probe+0x124/0x4e8 [rtc_omap] [ 11.049662] pc : [<bf0102a8>] lr : [<bf00fffc>] psr: 200f0013 [ 11.049662] sp : d1151c88 ip : d1151c88 fp : d1151cbc [ 11.061188] r10: d2c477e4 r9 : 00000000 r8 : 00000006 [ 11.066433] r7 : d5b5c8c0 r6 : dc130800 r5 : dc130810 r4 : d5b5c850 [ 11.072985] r3 : f9e3e000 r2 : 00000001 r1 : 00000005 r0 : d5b5c850 [ 11.079541] Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none [ 11.086705] Control: 10c5387d Table: 91154019 DAC: 00000051 [ 11.092473] Process systemd-udevd (pid: 154, stack limit = 0xd1150208) [ 11.099028] Stack: (0xd1151c88 to 0xd1152000) [ 11.103406] 1c80: dc130810 00000000 dc130818 dc130810 c0c85248 dc130810 [ 11.111622] 1ca0: ffffffed bf010ad8 fffffdfb 00000006 d1151cdc d1151cc0 c052d988 bf00fee4 [ 11.119839] 1cc0: dc130810 c0c85248 00000000 bf010ad8 d1151d04 d1151ce0 c052bca8 c052d93c [ 11.128054] 1ce0: dc130810 bf010ad8 dc130844 00000000 00000000 00000003 d1151d24 d1151d08 [ 11.136271] 1d00: c052be30 c052baac 00000000 bf010ad8 c052bd70 00000000 d1151d4c d1151d28 [ 11.144487] 1d20: c0529e30 c052bd7c dc030e8c dc128730 d10cd334 bf010ad8 d10cd300 c0c304b8 [ 11.152704] 1d40: d1151d5c d1151d50 c052b668 c0529dcc d1151d84 d1151d60 c052b1a0 c052b650 [ 11.160921] 1d60: bf010a3c d1151d70 bf010ad8 ffffe000 bf010b40 d2c47880 d1151d9c d1151d88 [ 11.169138] 1d80: c052c830 c052b0a4 bf013000 ffffe000 d1151dac d1151da0 c052d8e4 c052c7bc [ 11.177353] 1da0: d1151dbc d1151db0 bf01301c c052d8a8 d1151e34 d1151dc0 c0101714 bf01300c [ 11.185570] 1dc0: fffff000 dce6b11c d1150000 dc001e40 d59cfc80 dce6b11c d1150000 dc001e40 [ 11.193785] 1de0: d59cfec0 00008151 00000003 d2c477e4 d1151e2c d1151e00 c0201f94 c0201b70 [ 11.202002] 1e00: 00000001 e0afe000 00000001 00000005 d59cfec0 bf010b40 00000001 bf010b40 [ 11.210218] 1e20: d2c47880 00000001 d1151e5c d1151e38 c01b8fac c01016d4 bf010b40 d2c477c0 [ 11.218434] 1e40: d1151f44 00000001 bf010b40 d2c477c0 d1151f1c d1151e60 c01940bc c01b8f50 [ 11.226651] 1e60: bf010b4c 00007fff bf010b40 c01916a8 bf000000 c099c114 c099c0ec c099c144 [ 11.234868] 1e80: c099c0e0 c080429c bf010b4c e0b025b4 bf010ce0 d1151f44 bf010b88 bf010b40 [ 11.243083] 1ea0: d1151eec d1151eb0 c0219a74 c038aea4 00000003 00000000 00000000 00000000 [ 11.251299] 1ec0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 11.259515] 1ee0: 00000000 00000000 00000000 00000000 7fffffff 00000000 00000007 b6ef3f3c [ 11.267732] 1f00: 0000017b c0107d44 d1150000 00000000 d1151fa4 d1151f20 c0194844 c01924ec [ 11.275948] 1f20: 7fffffff 00000000 00000003 d1151f38 c01d90c0 e0afe000 00004604 00000000 [ 11.284164] 1f40: 00000000 e0afe000 00004604 e0b0226c e0b02198 e0b01224 00001d04 00002194 [ 11.292380] 1f60: 00000000 00000000 00000000 00001158 00000015 00000016 0000000f 0000000c [ 11.300597] 1f80: 0000000a 00000000 00000000 0047a4e8 00000000 00000000 00000000 d1151fa8 [ 11.308813] 1fa0: c0107b80 c01947a0 0047a4e8 00000000 00000007 b6ef3f3c 00000000 0047a938 [ 11.317028] 1fc0: 0047a4e8 00000000 00000000 0000017b 0047910c 0046bfc4 00000000 0047a938 [ 11.325245] 1fe0: bea39988 bea39978 b6eecc80 b6e25110 600e0010 00000007 4d5f4449 4c45444f [ 11.333452] Backtrace: [ 11.335942] [<bf00fed8>] (omap_rtc_probe [rtc_omap]) from [<c052d988>] (platform_drv_probe+0x58/0xb8) [ 11.345206] r8:00000006 r7:fffffdfb r6:bf010ad8 r5:ffffffed r4:dc130810 [ 11.351942] [<c052d930>] (platform_drv_probe) from [<c052bca8>] (driver_probe_device+0x208/0x2d0) [ 11.360854] r7:bf010ad8 r6:00000000 r5:c0c85248 r4:dc130810 [ 11.366542] [<c052baa0>] (driver_probe_device) from [<c052be30>] (__driver_attach+0xc0/0xc4) [ 11.375019] r9:00000003 r8:00000000 r7:00000000 r6:dc130844 r5:bf010ad8 r4:dc130810 [ 11.382799] [<c052bd70>] (__driver_attach) from [<c0529e30>] (bus_for_each_dev+0x70/0xa4) [ 11.391012] r7:00000000 r6:c052bd70 r5:bf010ad8 r4:00000000 [ 11.396697] [<c0529dc0>] (bus_for_each_dev) from [<c052b668>] (driver_attach+0x24/0x28) [ 11.404736] r6:c0c304b8 r5:d10cd300 r4:bf010ad8 [ 11.409375] [<c052b644>] (driver_attach) from [<c052b1a0>] (bus_add_driver+0x108/0x214) [ 11.417417] [<c052b098>] (bus_add_driver) from [<c052c830>] (driver_register+0x80/0xfc) [ 11.425456] r7:d2c47880 r6:bf010b40 r5:ffffe000 r4:bf010ad8 [ 11.431143] [<c052c7b0>] (driver_register) from [<c052d8e4>] (__platform_driver_register+0x48/0x50) [ 11.440226] r5:ffffe000 r4:bf013000 [ 11.443827] [<c052d89c>] (__platform_driver_register) from [<bf01301c>] (omap_rtc_driver_init+0x1c/0x24 [rtc_omap]) [ 11.454320] [<bf013000>] (omap_rtc_driver_init [rtc_omap]) from [<c0101714>] (do_one_initcall+0x4c/0x174) [ 11.463943] [<c01016c8>] (do_one_initcall) from [<c01b8fac>] (do_init_module+0x68/0x3ac) [ 11.472070] r8:00000001 r7:d2c47880 r6:bf010b40 r5:00000001 r4:bf010b40 [ 11.478809] [<c01b8f44>] (do_init_module) from [<c01940bc>] (load_module+0x1bdc/0x2134) [ 11.486848] r7:d2c477c0 r6:bf010b40 r5:00000001 r4:d1151f44 [ 11.492535] [<c01924e0>] (load_module) from [<c0194844>] (SyS_finit_module+0xb0/0xc0) [ 11.500402] r10:00000000 r9:d1150000 r8:c0107d44 r7:0000017b r6:b6ef3f3c r5:00000007 [ 11.508263] r4:00000000 [ 11.510815] [<c0194794>] (SyS_finit_module) from [<c0107b80>] (ret_fast_syscall+0x0/0x48) [ 11.519027] r6:00000000 r5:00000000 r4:0047a4e8 [ 11.523668] Code: eb592184 e2900000 13a00001 eaffff22 (e5d37054) [ 11.529791] ---[ end trace 4044a56f00c32e03 ]---
