linux/drivers/clocksource/bcm2835_timer.c

137 lines
3.1 KiB

ARM: bcm2835: add system timer The System Timer peripheral provides four 32-bit timer channels and a single 64-bit free running counter. Each channel has an output compare register, which is compared against the 32 least significant bits of the free running counter values, and generates an interrupt. Timer 3 is used as the Linux timer. The BCM2835 also contains an SP804-based timer module. However, it apparently has significant differences from the standard SP804 IP block, and Broadcom's documentation recommends using the system timer instead. This patch was extracted from git://github.com/lp0/linux.git branch rpi-split as of 2012/09/08, and modified as follows: * s/bcm2708/bcm2835/. * Modified device tree vendor prefix. * Moved to drivers/clocksource/. This looks like the desired location for such code now. * Added DT binding docs. * Moved struct sys_timer bcm2835_timer into time.c to encapsulate it more. * Simplified bcm2835_time_init() to find one matching node and operate on it, rather than looping over all matching nodes. This seems more consistent with other clocksource code. * Simplified bcm2835_time_init() using of_iomap(). * Renamed struct bcm2835_timer.index to match_mask to better represent its purpose. * s/printk(PR_INFO/pr_info(/ Signed-off-by: Chris Boot <bootc@bootc.net> Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Dom Cobley <popcornmix@gmail.com> Signed-off-by: Dom Cobley <dc4@broadcom.com> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-09-10 22:38:35 -06:00
ARM: bcm2835: add system timer The System Timer peripheral provides four 32-bit timer channels and a single 64-bit free running counter. Each channel has an output compare register, which is compared against the 32 least significant bits of the free running counter values, and generates an interrupt. Timer 3 is used as the Linux timer. The BCM2835 also contains an SP804-based timer module. However, it apparently has significant differences from the standard SP804 IP block, and Broadcom's documentation recommends using the system timer instead. This patch was extracted from git://github.com/lp0/linux.git branch rpi-split as of 2012/09/08, and modified as follows: * s/bcm2708/bcm2835/. * Modified device tree vendor prefix. * Moved to drivers/clocksource/. This looks like the desired location for such code now. * Added DT binding docs. * Moved struct sys_timer bcm2835_timer into time.c to encapsulate it more. * Simplified bcm2835_time_init() to find one matching node and operate on it, rather than looping over all matching nodes. This seems more consistent with other clocksource code. * Simplified bcm2835_time_init() using of_iomap(). * Renamed struct bcm2835_timer.index to match_mask to better represent its purpose. * s/printk(PR_INFO/pr_info(/ Signed-off-by: Chris Boot <bootc@bootc.net> Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Dom Cobley <popcornmix@gmail.com> Signed-off-by: Dom Cobley <dc4@broadcom.com> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-09-10 22:38:35 -06:00
ARM: bcm2835: add system timer The System Timer peripheral provides four 32-bit timer channels and a single 64-bit free running counter. Each channel has an output compare register, which is compared against the 32 least significant bits of the free running counter values, and generates an interrupt. Timer 3 is used as the Linux timer. The BCM2835 also contains an SP804-based timer module. However, it apparently has significant differences from the standard SP804 IP block, and Broadcom's documentation recommends using the system timer instead. This patch was extracted from git://github.com/lp0/linux.git branch rpi-split as of 2012/09/08, and modified as follows: * s/bcm2708/bcm2835/. * Modified device tree vendor prefix. * Moved to drivers/clocksource/. This looks like the desired location for such code now. * Added DT binding docs. * Moved struct sys_timer bcm2835_timer into time.c to encapsulate it more. * Simplified bcm2835_time_init() to find one matching node and operate on it, rather than looping over all matching nodes. This seems more consistent with other clocksource code. * Simplified bcm2835_time_init() using of_iomap(). * Renamed struct bcm2835_timer.index to match_mask to better represent its purpose. * s/printk(PR_INFO/pr_info(/ Signed-off-by: Chris Boot <bootc@bootc.net> Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Dom Cobley <popcornmix@gmail.com> Signed-off-by: Dom Cobley <dc4@broadcom.com> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-09-10 22:38:35 -06:00
ARM: bcm2835: add system timer The System Timer peripheral provides four 32-bit timer channels and a single 64-bit free running counter. Each channel has an output compare register, which is compared against the 32 least significant bits of the free running counter values, and generates an interrupt. Timer 3 is used as the Linux timer. The BCM2835 also contains an SP804-based timer module. However, it apparently has significant differences from the standard SP804 IP block, and Broadcom's documentation recommends using the system timer instead. This patch was extracted from git://github.com/lp0/linux.git branch rpi-split as of 2012/09/08, and modified as follows: * s/bcm2708/bcm2835/. * Modified device tree vendor prefix. * Moved to drivers/clocksource/. This looks like the desired location for such code now. * Added DT binding docs. * Moved struct sys_timer bcm2835_timer into time.c to encapsulate it more. * Simplified bcm2835_time_init() to find one matching node and operate on it, rather than looping over all matching nodes. This seems more consistent with other clocksource code. * Simplified bcm2835_time_init() using of_iomap(). * Renamed struct bcm2835_timer.index to match_mask to better represent its purpose. * s/printk(PR_INFO/pr_info(/ Signed-off-by: Chris Boot <bootc@bootc.net> Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Dom Cobley <popcornmix@gmail.com> Signed-off-by: Dom Cobley <dc4@broadcom.com> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-09-10 22:38:35 -06:00
locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-23 14:07:29 -07:00
ARM: bcm2835: add system timer The System Timer peripheral provides four 32-bit timer channels and a single 64-bit free running counter. Each channel has an output compare register, which is compared against the 32 least significant bits of the free running counter values, and generates an interrupt. Timer 3 is used as the Linux timer. The BCM2835 also contains an SP804-based timer module. However, it apparently has significant differences from the standard SP804 IP block, and Broadcom's documentation recommends using the system timer instead. This patch was extracted from git://github.com/lp0/linux.git branch rpi-split as of 2012/09/08, and modified as follows: * s/bcm2708/bcm2835/. * Modified device tree vendor prefix. * Moved to drivers/clocksource/. This looks like the desired location for such code now. * Added DT binding docs. * Moved struct sys_timer bcm2835_timer into time.c to encapsulate it more. * Simplified bcm2835_time_init() to find one matching node and operate on it, rather than looping over all matching nodes. This seems more consistent with other clocksource code. * Simplified bcm2835_time_init() using of_iomap(). * Renamed struct bcm2835_timer.index to match_mask to better represent its purpose. * s/printk(PR_INFO/pr_info(/ Signed-off-by: Chris Boot <bootc@bootc.net> Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Dom Cobley <popcornmix@gmail.com> Signed-off-by: Dom Cobley <dc4@broadcom.com> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-09-10 22:38:35 -06:00
ARM: bcm2835: add system timer The System Timer peripheral provides four 32-bit timer channels and a single 64-bit free running counter. Each channel has an output compare register, which is compared against the 32 least significant bits of the free running counter values, and generates an interrupt. Timer 3 is used as the Linux timer. The BCM2835 also contains an SP804-based timer module. However, it apparently has significant differences from the standard SP804 IP block, and Broadcom's documentation recommends using the system timer instead. This patch was extracted from git://github.com/lp0/linux.git branch rpi-split as of 2012/09/08, and modified as follows: * s/bcm2708/bcm2835/. * Modified device tree vendor prefix. * Moved to drivers/clocksource/. This looks like the desired location for such code now. * Added DT binding docs. * Moved struct sys_timer bcm2835_timer into time.c to encapsulate it more. * Simplified bcm2835_time_init() to find one matching node and operate on it, rather than looping over all matching nodes. This seems more consistent with other clocksource code. * Simplified bcm2835_time_init() using of_iomap(). * Renamed struct bcm2835_timer.index to match_mask to better represent its purpose. * s/printk(PR_INFO/pr_info(/ Signed-off-by: Chris Boot <bootc@bootc.net> Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Dom Cobley <popcornmix@gmail.com> Signed-off-by: Dom Cobley <dc4@broadcom.com> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-09-10 22:38:35 -06:00
ARM: bcm2835: add system timer The System Timer peripheral provides four 32-bit timer channels and a single 64-bit free running counter. Each channel has an output compare register, which is compared against the 32 least significant bits of the free running counter values, and generates an interrupt. Timer 3 is used as the Linux timer. The BCM2835 also contains an SP804-based timer module. However, it apparently has significant differences from the standard SP804 IP block, and Broadcom's documentation recommends using the system timer instead. This patch was extracted from git://github.com/lp0/linux.git branch rpi-split as of 2012/09/08, and modified as follows: * s/bcm2708/bcm2835/. * Modified device tree vendor prefix. * Moved to drivers/clocksource/. This looks like the desired location for such code now. * Added DT binding docs. * Moved struct sys_timer bcm2835_timer into time.c to encapsulate it more. * Simplified bcm2835_time_init() to find one matching node and operate on it, rather than looping over all matching nodes. This seems more consistent with other clocksource code. * Simplified bcm2835_time_init() using of_iomap(). * Renamed struct bcm2835_timer.index to match_mask to better represent its purpose. * s/printk(PR_INFO/pr_info(/ Signed-off-by: Chris Boot <bootc@bootc.net> Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Dom Cobley <popcornmix@gmail.com> Signed-off-by: Dom Cobley <dc4@broadcom.com> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-09-10 22:38:35 -06:00
ARM: bcm2835: add system timer The System Timer peripheral provides four 32-bit timer channels and a single 64-bit free running counter. Each channel has an output compare register, which is compared against the 32 least significant bits of the free running counter values, and generates an interrupt. Timer 3 is used as the Linux timer. The BCM2835 also contains an SP804-based timer module. However, it apparently has significant differences from the standard SP804 IP block, and Broadcom's documentation recommends using the system timer instead. This patch was extracted from git://github.com/lp0/linux.git branch rpi-split as of 2012/09/08, and modified as follows: * s/bcm2708/bcm2835/. * Modified device tree vendor prefix. * Moved to drivers/clocksource/. This looks like the desired location for such code now. * Added DT binding docs. * Moved struct sys_timer bcm2835_timer into time.c to encapsulate it more. * Simplified bcm2835_time_init() to find one matching node and operate on it, rather than looping over all matching nodes. This seems more consistent with other clocksource code. * Simplified bcm2835_time_init() using of_iomap(). * Renamed struct bcm2835_timer.index to match_mask to better represent its purpose. * s/printk(PR_INFO/pr_info(/ Signed-off-by: Chris Boot <bootc@bootc.net> Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Dom Cobley <popcornmix@gmail.com> Signed-off-by: Dom Cobley <dc4@broadcom.com> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-09-10 22:38:35 -06:00
ARM: bcm2835: add system timer The System Timer peripheral provides four 32-bit timer channels and a single 64-bit free running counter. Each channel has an output compare register, which is compared against the 32 least significant bits of the free running counter values, and generates an interrupt. Timer 3 is used as the Linux timer. The BCM2835 also contains an SP804-based timer module. However, it apparently has significant differences from the standard SP804 IP block, and Broadcom's documentation recommends using the system timer instead. This patch was extracted from git://github.com/lp0/linux.git branch rpi-split as of 2012/09/08, and modified as follows: * s/bcm2708/bcm2835/. * Modified device tree vendor prefix. * Moved to drivers/clocksource/. This looks like the desired location for such code now. * Added DT binding docs. * Moved struct sys_timer bcm2835_timer into time.c to encapsulate it more. * Simplified bcm2835_time_init() to find one matching node and operate on it, rather than looping over all matching nodes. This seems more consistent with other clocksource code. * Simplified bcm2835_time_init() using of_iomap(). * Renamed struct bcm2835_timer.index to match_mask to better represent its purpose. * s/printk(PR_INFO/pr_info(/ Signed-off-by: Chris Boot <bootc@bootc.net> Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Dom Cobley <popcornmix@gmail.com> Signed-off-by: Dom Cobley <dc4@broadcom.com> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-09-10 22:38:35 -06:00
ARM: bcm2835: add system timer The System Timer peripheral provides four 32-bit timer channels and a single 64-bit free running counter. Each channel has an output compare register, which is compared against the 32 least significant bits of the free running counter values, and generates an interrupt. Timer 3 is used as the Linux timer. The BCM2835 also contains an SP804-based timer module. However, it apparently has significant differences from the standard SP804 IP block, and Broadcom's documentation recommends using the system timer instead. This patch was extracted from git://github.com/lp0/linux.git branch rpi-split as of 2012/09/08, and modified as follows: * s/bcm2708/bcm2835/. * Modified device tree vendor prefix. * Moved to drivers/clocksource/. This looks like the desired location for such code now. * Added DT binding docs. * Moved struct sys_timer bcm2835_timer into time.c to encapsulate it more. * Simplified bcm2835_time_init() to find one matching node and operate on it, rather than looping over all matching nodes. This seems more consistent with other clocksource code. * Simplified bcm2835_time_init() using of_iomap(). * Renamed struct bcm2835_timer.index to match_mask to better represent its purpose. * s/printk(PR_INFO/pr_info(/ Signed-off-by: Chris Boot <bootc@bootc.net> Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Dom Cobley <popcornmix@gmail.com> Signed-off-by: Dom Cobley <dc4@broadcom.com> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-09-10 22:38:35 -06:00
ARM: bcm2835: add system timer The System Timer peripheral provides four 32-bit timer channels and a single 64-bit free running counter. Each channel has an output compare register, which is compared against the 32 least significant bits of the free running counter values, and generates an interrupt. Timer 3 is used as the Linux timer. The BCM2835 also contains an SP804-based timer module. However, it apparently has significant differences from the standard SP804 IP block, and Broadcom's documentation recommends using the system timer instead. This patch was extracted from git://github.com/lp0/linux.git branch rpi-split as of 2012/09/08, and modified as follows: * s/bcm2708/bcm2835/. * Modified device tree vendor prefix. * Moved to drivers/clocksource/. This looks like the desired location for such code now. * Added DT binding docs. * Moved struct sys_timer bcm2835_timer into time.c to encapsulate it more. * Simplified bcm2835_time_init() to find one matching node and operate on it, rather than looping over all matching nodes. This seems more consistent with other clocksource code. * Simplified bcm2835_time_init() using of_iomap(). * Renamed struct bcm2835_timer.index to match_mask to better represent its purpose. * s/printk(PR_INFO/pr_info(/ Signed-off-by: Chris Boot <bootc@bootc.net> Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Dom Cobley <popcornmix@gmail.com> Signed-off-by: Dom Cobley <dc4@broadcom.com> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-09-10 22:38:35 -06:00
ARM: bcm2835: add system timer The System Timer peripheral provides four 32-bit timer channels and a single 64-bit free running counter. Each channel has an output compare register, which is compared against the 32 least significant bits of the free running counter values, and generates an interrupt. Timer 3 is used as the Linux timer. The BCM2835 also contains an SP804-based timer module. However, it apparently has significant differences from the standard SP804 IP block, and Broadcom's documentation recommends using the system timer instead. This patch was extracted from git://github.com/lp0/linux.git branch rpi-split as of 2012/09/08, and modified as follows: * s/bcm2708/bcm2835/. * Modified device tree vendor prefix. * Moved to drivers/clocksource/. This looks like the desired location for such code now. * Added DT binding docs. * Moved struct sys_timer bcm2835_timer into time.c to encapsulate it more. * Simplified bcm2835_time_init() to find one matching node and operate on it, rather than looping over all matching nodes. This seems more consistent with other clocksource code. * Simplified bcm2835_time_init() using of_iomap(). * Renamed struct bcm2835_timer.index to match_mask to better represent its purpose. * s/printk(PR_INFO/pr_info(/ Signed-off-by: Chris Boot <bootc@bootc.net> Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Dom Cobley <popcornmix@gmail.com> Signed-off-by: Dom Cobley <dc4@broadcom.com> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-09-10 22:38:35 -06:00
ARM: bcm2835: add system timer The System Timer peripheral provides four 32-bit timer channels and a single 64-bit free running counter. Each channel has an output compare register, which is compared against the 32 least significant bits of the free running counter values, and generates an interrupt. Timer 3 is used as the Linux timer. The BCM2835 also contains an SP804-based timer module. However, it apparently has significant differences from the standard SP804 IP block, and Broadcom's documentation recommends using the system timer instead. This patch was extracted from git://github.com/lp0/linux.git branch rpi-split as of 2012/09/08, and modified as follows: * s/bcm2708/bcm2835/. * Modified device tree vendor prefix. * Moved to drivers/clocksource/. This looks like the desired location for such code now. * Added DT binding docs. * Moved struct sys_timer bcm2835_timer into time.c to encapsulate it more. * Simplified bcm2835_time_init() to find one matching node and operate on it, rather than looping over all matching nodes. This seems more consistent with other clocksource code. * Simplified bcm2835_time_init() using of_iomap(). * Renamed struct bcm2835_timer.index to match_mask to better represent its purpose. * s/printk(PR_INFO/pr_info(/ Signed-off-by: Chris Boot <bootc@bootc.net> Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Dom Cobley <popcornmix@gmail.com> Signed-off-by: Dom Cobley <dc4@broadcom.com> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-09-10 22:38:35 -06:00
ARM: bcm2835: add system timer The System Timer peripheral provides four 32-bit timer channels and a single 64-bit free running counter. Each channel has an output compare register, which is compared against the 32 least significant bits of the free running counter values, and generates an interrupt. Timer 3 is used as the Linux timer. The BCM2835 also contains an SP804-based timer module. However, it apparently has significant differences from the standard SP804 IP block, and Broadcom's documentation recommends using the system timer instead. This patch was extracted from git://github.com/lp0/linux.git branch rpi-split as of 2012/09/08, and modified as follows: * s/bcm2708/bcm2835/. * Modified device tree vendor prefix. * Moved to drivers/clocksource/. This looks like the desired location for such code now. * Added DT binding docs. * Moved struct sys_timer bcm2835_timer into time.c to encapsulate it more. * Simplified bcm2835_time_init() to find one matching node and operate on it, rather than looping over all matching nodes. This seems more consistent with other clocksource code. * Simplified bcm2835_time_init() using of_iomap(). * Renamed struct bcm2835_timer.index to match_mask to better represent its purpose. * s/printk(PR_INFO/pr_info(/ Signed-off-by: Chris Boot <bootc@bootc.net> Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Dom Cobley <popcornmix@gmail.com> Signed-off-by: Dom Cobley <dc4@broadcom.com> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Acked-by: Arnd Bergmann <arnd@arndb.de>
2012-09-10 22:38:35 -06:00