user/sven/linux.git/drivers/rtc/rtc-tegra.c, branch v4.9.80

rtc: tegra: Implement clock handling

2017-04-21T07:31:24Z

commit 5fa4086987506b2ab8c92f8f99f2295db9918856 upstream. 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 Acked-By Peter De Schrijver Signed-off-by: Thierry Reding Signed-off-by: Alexandre Belloni [bwh: Backported to 4.9: adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

rtc: constify rtc_class_ops structures

2016-09-01T23:24:06Z

Check for rtc_class_ops structures that are only passed to devm_rtc_device_register, rtc_device_register, platform_device_register_data, all of which declare the corresponding parameter as const. Declare rtc_class_ops structures that have these properties as const. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // @r disable optional_qualifier@ identifier i; position p; @@ static struct rtc_class_ops i@p = { ... }; @ok@ identifier r.i; expression e1,e2,e3,e4; position p; @@ ( devm_rtc_device_register(e1,e2,&i@p,e3) | rtc_device_register(e1,e2,&i@p,e3) | platform_device_register_data(e1,e2,e3,&i@p,e4) ) @bad@ position p != {r.p,ok.p}; identifier r.i; @@ i@p @depends on !bad disable optional_qualifier@ identifier r.i; @@ static +const struct rtc_class_ops i = { ... }; // Signed-off-by: Julia Lawall Acked-by: Baruch Siach Acked-by: Hans Ulli Kroll Acked-by: Linus Walleij Acked-by: Thierry Reding Signed-off-by: Alexandre Belloni

rtc: simplify implementations of read_alarm

2016-07-09T08:24:45Z

Since commit d68778b80dd7 ("rtc: initialize output parameter for read alarm to "uninitialized"") there is no need to explicitly set unsupported members to -1. So drop the respective assignments from drivers. Signed-off-by: Uwe Kleine-König Signed-off-by: Alexandre Belloni

rtc: remove use of seq_printf return value

2015-04-15T23:35:24Z

The seq_printf return value, because it's frequently misused, will eventually be converted to void. See: commit 1f33c41c03da ("seq_file: Rename seq_overflow() to seq_has_overflowed() and make public") Signed-off-by: Joe Perches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

rtc: drop owner assignment from platform_drivers

2014-10-20T14:21:31Z

A platform_driver does not need to set an owner, it will be populated by the driver core. Signed-off-by: Wolfram Sang

drivers/rtc: don't check resource with devm_ioremap_resource

2013-05-18T09:57:07Z

devm_ioremap_resource does sanity checks on the given resource. No need to duplicate this in the driver. Signed-off-by: Wolfram Sang Acked-by: Stephen Warren

drivers/rtc/rtc-tegra.c: use managed rtc_device_register()

2013-04-30T01:28:28Z

Use devm_rtc_device_register() for registering RTC device. This will reduce the code for unregistering RTC device in cleanup path and remove the implementation of remove callback of platform driver. Signed-off-by: Laxman Dewangan Reviewed-by: Thierry Reding Reviewed-by: Stephen Warren Cc: Jingoo Han Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

drivers/rtc/rtc-tegra.c: set irq name as device name

2013-04-30T01:28:28Z

The irq name of tegra rtc shows as "rtc alarm" which actually does not reflect the name related to driver. Passing the device name to have the irq names with driver name. Signed-off-by: Laxman Dewangan Reviewed-by: Thierry Reding Reviewed-by: Stephen Warren Cc: Jingoo Han Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

drivers/rtc/rtc-tegra.c: use struct dev_pm_ops for power management

2013-04-30T01:28:28Z

Make the Tegra RTC controller driver define its PM callbacks through a struct dev_pm_ops object rather than by using legacy PM hooks in struct platform_driver. Signed-off-by: Laxman Dewangan Reviewed-by: Thierry Reding Reviewed-by: Stephen Warren Cc: Jingoo Han Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

drivers/rtc/rtc-tegra.c: protect suspend/resume callbacks with CONFIG_PM_SLEEP

2013-04-30T01:28:28Z

CONFIG_PM doesn't actually enable any of the PM callbacks, it only allows to enable CONFIG_PM_SLEEP and CONFIG_PM_RUNTIME. This means if CONFIG_PM is used to protect system sleep callbacks then it may end up unreferenced if only runtime PM is enabled. Hence protecting sleep callbacks with CONFIG_PM_SLEEP. Signed-off-by: Laxman Dewangan Reviewed-by: Thierry Reding Reviewed-by: Stephen Warren Cc: Jingoo Han Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds