Star64_linux/drivers/rtc
Thierry Reding 5fa4086987 rtc: tegra: Implement clock handling
Accessing the registers of the RTC block on Tegra requires the module
clock to be enabled. This only works because the RTC module clock will
be enabled by default during early boot. However, because the clock is
unused, the CCF will disable it at late_init time. This causes the RTC
to become unusable afterwards. This can easily be reproduced by trying
to use the RTC:

	$ hwclock --rtc /dev/rtc1

This will hang the system. I ran into this by following up on a report
by Martin Michlmayr that reboot wasn't working on Tegra210 systems. It
turns out that the rtc-tegra driver's ->shutdown() implementation will
hang the CPU, because of the disabled clock, before the system can be
rebooted.

What confused me for a while is that the same driver is used on prior
Tegra generations where the hang can not be observed. However, as Peter
De Schrijver pointed out, this is because on 32-bit Tegra chips the RTC
clock is enabled by the tegra20_timer.c clocksource driver, which uses
the RTC to provide a persistent clock. This code is never enabled on
64-bit Tegra because the persistent clock infrastructure does not exist
on 64-bit ARM.

The proper fix for this is to add proper clock handling to the RTC
driver in order to ensure that the clock is enabled when the driver
requires it. All device trees contain the clock already, therefore
no additional changes are required.

Reported-by: Martin Michlmayr <tbm@cyrius.com>
Acked-By Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
2017-01-23 00:46:55 +01:00
..
class.c
hctosys.c
interface.c ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
Kconfig rtc: add STM32 RTC driver 2017-01-13 01:40:31 +01:00
Makefile rtc: add STM32 RTC driver 2017-01-13 01:40:31 +01:00
rtc-88pm80x.c
rtc-88pm860x.c
rtc-ab-b5ze-s3.c
rtc-ab3100.c
rtc-ab8500.c
rtc-abx80x.c
rtc-ac100.c
rtc-armada38x.c rtc: armada38x: make struct rtc_class_ops const 2017-01-12 12:33:58 +01:00
rtc-as3722.c
rtc-asm9260.c
rtc-at32ap700x.c
rtc-at91rm9200.c
rtc-at91rm9200.h
rtc-at91sam9.c
rtc-au1xxx.c rtc: constify rtc_class_ops structures 2017-01-11 17:23:06 +01:00
rtc-bfin.c rtc: constify rtc_class_ops structures 2017-01-11 17:23:06 +01:00
rtc-bq32k.c
rtc-bq4802.c
rtc-cmos.c RTC for 4.10 2016-12-18 18:18:03 -08:00
rtc-coh901331.c
rtc-core.h
rtc-da9052.c
rtc-da9055.c
rtc-da9063.c
rtc-davinci.c
rtc-dev.c
rtc-digicolor.c
rtc-dm355evm.c rtc: constify rtc_class_ops structures 2017-01-11 17:23:06 +01:00
rtc-ds1216.c
rtc-ds1286.c
rtc-ds1302.c
rtc-ds1305.c
rtc-ds1307.c rtc: ds1307: Add ACPI support 2016-12-19 00:59:07 +01:00
rtc-ds1343.c
rtc-ds1347.c
rtc-ds1374.c rtc: ds1374: Merge conditional + WARN_ON() 2016-12-07 16:34:43 +01:00
rtc-ds1390.c
rtc-ds1511.c
rtc-ds1553.c
rtc-ds1672.c
rtc-ds1685.c
rtc-ds1742.c
rtc-ds2404.c
rtc-ds3232.c
rtc-efi-platform.c
rtc-efi.c
rtc-em3027.c
rtc-ep93xx.c
rtc-fm3130.c
rtc-gemini.c
rtc-generic.c
rtc-hid-sensor-time.c
rtc-hym8563.c
rtc-imxdi.c rtc: constify rtc_class_ops structures 2017-01-11 17:23:06 +01:00
rtc-isl1208.c
rtc-isl12022.c
rtc-jz4740.c rtc: jz4740: make the driver builtin only 2016-11-09 01:37:03 +01:00
rtc-lib.c rtc: make rtc-lib explicitly non-modular 2016-11-04 23:31:29 +01:00
rtc-lp8788.c
rtc-lpc24xx.c
rtc-lpc32xx.c
rtc-ls1x.c rtc: constify rtc_class_ops structures 2017-01-11 17:23:06 +01:00
rtc-m41t80.c
rtc-m41t93.c
rtc-m41t94.c
rtc-m48t35.c
rtc-m48t59.c
rtc-m48t86.c
rtc-max6900.c
rtc-max6902.c
rtc-max6916.c
rtc-max8907.c
rtc-max8925.c
rtc-max8997.c
rtc-max8998.c
rtc-max77686.c
rtc-mc13xxx.c
rtc-mc146818-lib.c
rtc-mcp795.c rtc: mcp795: add alarm support. 2017-01-11 17:23:04 +01:00
rtc-moxart.c
rtc-mpc5121.c
rtc-mrst.c
rtc-msm6242.c
rtc-mt6397.c
rtc-mv.c
rtc-mxc.c rtc: constify rtc_class_ops structures 2017-01-11 17:23:06 +01:00
rtc-nuc900.c
rtc-omap.c rtc: omap: prevent disabling of clock/module during suspend 2016-11-04 23:11:39 +01:00
rtc-opal.c
rtc-palmas.c
rtc-pcap.c
rtc-pcf2123.c
rtc-pcf2127.c
rtc-pcf8523.c
rtc-pcf8563.c
rtc-pcf8583.c
rtc-pcf50633.c
rtc-pcf85063.c rtc: pcf85063: do not register a RTC device if chip is not present 2016-11-04 23:08:59 +01:00
rtc-pic32.c
rtc-pl030.c
rtc-pl031.c
rtc-pm8xxx.c
rtc-proc.c
rtc-ps3.c
rtc-puv3.c
rtc-pxa.c
rtc-r7301.c rtc: add support for EPSON TOYOCOM RTC-7301SF/DG 2016-12-19 00:59:21 +01:00
rtc-r9701.c
rtc-rc5t583.c
rtc-rk808.c
rtc-rp5c01.c
rtc-rs5c313.c
rtc-rs5c348.c
rtc-rs5c372.c
rtc-rv3029c2.c
rtc-rv8803.c
rtc-rx4581.c
rtc-rx6110.c
rtc-rx8010.c rtc: rx8010: change lock mechanism 2017-01-04 23:39:15 +01:00
rtc-rx8025.c
rtc-rx8581.c
rtc-s3c.c
rtc-s3c.h
rtc-s5m.c
rtc-s35390a.c
rtc-sa1100.c
rtc-sa1100.h
rtc-sh.c rtc: constify rtc_class_ops structures 2017-01-11 17:23:06 +01:00
rtc-sirfsoc.c
rtc-snvs.c
rtc-spear.c
rtc-st-lpc.c
rtc-starfire.c rtc: sparc: make starfire explicitly non-modular 2016-11-04 23:31:31 +01:00
rtc-stk17ta8.c
rtc-stm32.c rtc: stm32: fix building without CONFIG_OF 2017-01-13 17:51:53 +01:00
rtc-stmp3xxx.c
rtc-sun4v.c rtc: sparc: make sun4v explicitly non-modular 2016-11-04 23:31:33 +01:00
rtc-sun6i.c
rtc-sunxi.c
rtc-sysfs.c
rtc-tegra.c rtc: tegra: Implement clock handling 2017-01-23 00:46:55 +01:00
rtc-test.c
rtc-tile.c
rtc-tps6586x.c
rtc-tps65910.c rtc: tps65910: use 'unsigned int' instead of 'unsigned' in arguments 2017-01-10 01:32:51 +01:00
rtc-tps80031.c
rtc-twl.c rtc: twl: make driver DT only 2016-11-30 21:21:33 +01:00
rtc-tx4939.c
rtc-v3020.c
rtc-vr41xx.c
rtc-vt8500.c
rtc-wm831x.c
rtc-wm8350.c
rtc-x1205.c
rtc-xgene.c
rtc-zynqmp.c
systohc.c