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.
Signed-off-by: Wilken Gottwalt
---
Changes in v7:
- changed probe to use to devm_* and devm_add_action_* function
Changes in v6:
- changed probe/remove function to use classic functions to better
handle failure situations
Changes in v5:
- changed symbols to the earliest known supported SoC (sun6i/a31)
- changed init back to classic probe/remove callbacks
Changes in v4:
- further simplified driver
- fixed an add_action_and_reset_ function issue
- changed bindings from sun8i-hwspinlock to sun8i-a33-hwspinlock
Changes in v3:
- moved test description to cover letter
- changed name and symbols from sunxi to sun8i
- improved driver description
- further simplified driver
- fully switched to devm_* and devm_add_action_* functions
Changes in v2:
- added suggestions from Bjorn Andersson and Maxime Ripard
- provided better driver and test description
---
MAINTAINERS | 6 +
drivers/hwspinlock/Kconfig| 9 ++
drivers/hwspinlock/Makefile | 1 +
drivers/hwspinlock/sun6i_hwspinlock.c | 210 ++
4 files changed, 226 insertions(+)
create mode 100644 drivers/hwspinlock/sun6i_hwspinlock.c
diff --git a/MAINTAINERS b/MAINTAINERS
index d92f85ca831d..d5821c52c502 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -734,6 +734,12 @@ L: linux-cry...@vger.kernel.org
S: Maintained
F: drivers/crypto/allwinner/
+ALLWINNER HARDWARE SPINLOCK SUPPORT
+M: Wilken Gottwalt
+S: Maintained
+F: Documentation/devicetree/bindings/hwlock/allwinner,sun6i-hwspinlock.yaml
+F: drivers/hwspinlock/sun6i_hwspinlock.c
+
ALLWINNER THERMAL DRIVER
M: Vasily Khoruzhick
M: Yangtao Li
diff --git a/drivers/hwspinlock/Kconfig b/drivers/hwspinlock/Kconfig
index 32cd26352f38..56ecc1aa3166 100644
--- a/drivers/hwspinlock/Kconfig
+++ b/drivers/hwspinlock/Kconfig
@@ -55,6 +55,15 @@ 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
diff --git a/drivers/hwspinlock/Makefile b/drivers/hwspinlock/Makefile
index ed053e3f02be..83ec4f03decc 100644
--- a/drivers/hwspinlock/Makefile
+++ b/drivers/hwspinlock/Makefile
@@ -9,4 +9,5 @@ obj-$(CONFIG_HWSPINLOCK_QCOM) += qcom_hwspinlock.o
obj-$(CONFIG_HWSPINLOCK_SIRF) += sirf_hwspinlock.o
obj-$(CONFIG_HWSPINLOCK_SPRD) += sprd_hwspinlock.o
obj-$(CONFIG_HWSPINLOCK_STM32) += stm32_hwspinlock.o
+obj-$(CONFIG_HWSPINLOCK_SUN6I) += sun6i_hwspinlock.o
obj-$(CONFIG_HSEM_U8500) += u8500_hsem.o
diff --git a/drivers/hwspinlock/sun6i_hwspinlock.c
b/drivers/hwspinlock/sun6i_hwspinlock.c
new file mode 100644
index ..c2d314588046
--- /dev/null
+++ b/drivers/hwspinlock/sun6i_hwspinlock.c
@@ -0,0 +1,210 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * sun6i_hwspinlock.c - hardware spinlock driver for sun6i compatible
Allwinner SoCs
+ * Copyright (C) 2020 Wilken Gottwalt
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#include "hwspinlock_internal.h"
+
+#define DRIVER_NAME"sun6i_hwspinlock"
+
+#define SPINLOCK_BASE_ID 0 /* there is only one hwspinlock device per
SoC */
+#define SPINLOCK_SYSSTATUS_REG 0x
+#define SPINLOCK_LOCK_REGN
