diff options
| author | Wilken Gottwalt <wilken.gottwalt@posteo.net> | 2021-03-14 10:31:13 +0100 |
|---|---|---|
| committer | Bjorn Andersson <bjorn.andersson@linaro.org> | 2021-05-27 22:19:42 -0500 |
| commit | 3c881e05c814c970e4f9577446a9d3461d134607 (patch) | |
| tree | 4541c6fdf1ae19605c969a56a0eb7bb18d3dbde4 /drivers/hwspinlock/Kconfig | |
| parent | f9e784dcb63f56157f7d12abdab584cc393515b1 (diff) | |
hwspinlock: add sun6i hardware spinlock support
Adds the sun6i_hwspinlock driver for the hardware spinlock unit found in
most of the sun6i compatible SoCs.
This unit provides at least 32 spinlocks in hardware. The implementation
supports 32, 64, 128 or 256 32bit registers. A lock can be taken by
reading a register and released by writing a 0 to it. This driver
supports all 4 spinlock setups, but for now only the first setup (32
locks) seem to exist in available devices. This spinlock unit is shared
between all ARM cores and the embedded companion core. All of them can
take/release a lock with a single cycle operation. It can be used to
sync access to devices shared by the ARM cores and the companion core.
There are two ways to check if a lock is taken. The first way is to read
a lock. If a 0 is returned, the lock was free and is taken now. If an 1
is returned, the caller has to try again. Which means the lock is taken.
The second way is to read a 32bit wide status register where every bit
represents one of the 32 first locks. According to the datasheets this
status register supports only the 32 first locks. This is the reason the
first way (lock read/write) approach is used to be able to cover all 256
locks in future devices. The driver also reports the amount of supported
locks via debugfs.
Reviewed-by: Samuel Holland <samuel@sholland.org>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Wilken Gottwalt <wilken.gottwalt@posteo.net>
Link: https://lore.kernel.org/r/bfd2b97307c2321b15c09683f4bd5e1fcc792f13.1615713499.git.wilken.gottwalt@posteo.net
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Diffstat (limited to 'drivers/hwspinlock/Kconfig')
| -rw-r--r-- | drivers/hwspinlock/Kconfig | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/hwspinlock/Kconfig b/drivers/hwspinlock/Kconfig index 53e13476e831..3874d15b0e9b 100644 --- a/drivers/hwspinlock/Kconfig +++ b/drivers/hwspinlock/Kconfig @@ -44,6 +44,15 @@ config HWSPINLOCK_STM32 If unsure, say N. +config HWSPINLOCK_SUN6I + tristate "SUN6I Hardware Spinlock device" + depends on ARCH_SUNXI || COMPILE_TEST + help + Say y here to support the SUN6I Hardware Spinlock device which can be + found in most of the sun6i compatible Allwinner SoCs. + + If unsure, say N. + config HSEM_U8500 tristate "STE Hardware Semaphore functionality" depends on ARCH_U8500 || COMPILE_TEST |