[PATCH v2 0/3] Add support for hwspinlock on A64 SoC

[PATCH v2 0/3] Add support for hwspinlock on A64 SoC

[Nikolay Borisov]

Here's v2 of hwspinlock support in A64 SoC. Main changes:

* Rewrote dt bindings in yaml
* Re-arranged hwspinlock node in dts to follow ascending address order
* Sorted includes alphabetically
* Minor style changes
* Use GENMASK/FIELD_GET to query number of locks from mmio register
* Separate hwspinlock_device from sun50i_hwspinlock. This enables to utilize
devm_add_action_or_reset, which results in cleaner error handling in the probe
function.
* Switched to device managed resources where applicable.


This was tested on a pine64 board. I loadeded/unloaded the driver checking the
state of clock/reset/sysstatus registers as well as trying lock/unlock operations
(using the devmem busybox utility).

Nikolay Borisov (3):
  hwspinlock: sunxi: Implement support for Allwinner's A64 SoC
  arm64: dts: allwinner: a64: Add hwspinlock node
  dt-bindings: hwlock: Document A64 hwspinlock bindings

 .../allwinner,sun50i-a64-hwspinlock.yaml      |  47 +++++
 arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi |   9 +
 drivers/hwspinlock/Kconfig                    |   9 +
 drivers/hwspinlock/Makefile                   |   1 +
 drivers/hwspinlock/sun50i_hwspinlock.c        | 163 ++++++++++++++++++
 5 files changed, 229 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.yaml
 create mode 100644 drivers/hwspinlock/sun50i_hwspinlock.c

--
2.17.1

[PATCH v2 1/3] hwspinlock: sunxi: Implement support for Allwinner's A64 SoC

[Nikolay Borisov]

Based on the datasheet this implements support for the hwspinlock IP
block.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 drivers/hwspinlock/Kconfig             |   9 ++
 drivers/hwspinlock/Makefile            |   1 +
 drivers/hwspinlock/sun50i_hwspinlock.c | 163 +++++++++++++++++++++++++
 3 files changed, 173 insertions(+)
 create mode 100644 drivers/hwspinlock/sun50i_hwspinlock.c

diff --git a/drivers/hwspinlock/Kconfig b/drivers/hwspinlock/Kconfig
index 37740e992cfa..aff39bad3e90 100644
--- a/drivers/hwspinlock/Kconfig
+++ b/drivers/hwspinlock/Kconfig
@@ -68,3 +68,12 @@ config HSEM_U8500
 	  SoC.
 
 	  If unsure, say N.
+
+config HWSPINLOCK_SUN50I
+	tristate "Allwinner Hardware Spinlock device"
+	depends on ARCH_SUNXI
+	depends on HWSPINLOCK
+	help
+	  Say y here to support the SUNXI Hardware Spinlock device.
+
+	  If unsure, say N.
diff --git a/drivers/hwspinlock/Makefile b/drivers/hwspinlock/Makefile
index ed053e3f02be..ebabe5c7b7ef 100644
--- a/drivers/hwspinlock/Makefile
+++ b/drivers/hwspinlock/Makefile
@@ -8,5 +8,6 @@ obj-$(CONFIG_HWSPINLOCK_OMAP)		+= omap_hwspinlock.o
 obj-$(CONFIG_HWSPINLOCK_QCOM)		+= qcom_hwspinlock.o
 obj-$(CONFIG_HWSPINLOCK_SIRF)		+= sirf_hwspinlock.o
 obj-$(CONFIG_HWSPINLOCK_SPRD)		+= sprd_hwspinlock.o
+obj-$(CONFIG_HWSPINLOCK_SUN50I)		+= sun50i_hwspinlock.o
 obj-$(CONFIG_HWSPINLOCK_STM32)		+= stm32_hwspinlock.o
 obj-$(CONFIG_HSEM_U8500)		+= u8500_hsem.o
diff --git a/drivers/hwspinlock/sun50i_hwspinlock.c b/drivers/hwspinlock/sun50i_hwspinlock.c
new file mode 100644
index 000000000000..2b54c0a0148d
--- /dev/null
+++ b/drivers/hwspinlock/sun50i_hwspinlock.c
@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Author: Nikolay Borisov <nborisov@suse.com> */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/hwspinlock.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+#include "hwspinlock_internal.h"
+
+/* Bits containing number of locks in SPINLOCK_SYSSTATUS_REG */
+#define SPINLOCK_LOCKS_NUM GENMASK(29, 28)
+
+/* Spinlock register offsets */
+#define SPINLOCK_ID(X) (0x100 + 0x4 * X)
+
+/* Possible values of SPINLOCK_LOCK_REG */
+#define SPINLOCK_NOTTAKEN		(0)	/* free */
+#define SPINLOCK_TAKEN			(1)	/* locked */
+
+struct sun50i_hwspinlock {
+	struct clk *clk;
+	struct reset_control *reset;
+	struct hwspinlock_device *bank;
+};
+
+static int sun50i_hwspinlock_trylock(struct hwspinlock *lock)
+{
+	void __iomem *lock_addr = lock->priv;
+
+	/* attempt to acquire the lock by reading its value */
+	return readl(lock_addr) == SPINLOCK_NOTTAKEN;
+}
+
+static void sun50i_hwspinlock_unlock(struct hwspinlock *lock)
+{
+	void __iomem *lock_addr = lock->priv;
+
+	/* release the lock by writing 0 to it */
+	writel(SPINLOCK_NOTTAKEN, lock_addr);
+}
+
+static const struct hwspinlock_ops sun50i_hwspinlock_ops = {
+	.trylock	= sun50i_hwspinlock_trylock,
+	.unlock		= sun50i_hwspinlock_unlock,
+};
+
+static int sun50i_get_num_locks(void __iomem *io_base)
+{
+	u32 i = readl(io_base);
+	i = FIELD_GET(SPINLOCK_LOCKS_NUM, i);
+
+	switch (i) {
+	case 0x1: return 32;
+	case 0x2: return 64;
+	case 0x3: return 128;
+	case 0x4: return 256;
+	}
+
+	return 0;
+}
+
+static int sun50i_hwspinlock_probe(struct platform_device *pdev)
+{
+	struct sun50i_hwspinlock *hw;
+	void __iomem *io_base;
+	struct clk *clk;
+	struct reset_control *reset;
+	int i, ret, num_locks;
+
+	io_base = devm_platform_ioremap_resource(&pdev->dev, 0);
+	if (IS_ERR(io_base))
+		return PTR_ERR(io_base);
+
+	hw = devm_kzalloc(&pdev->dev, sizeof(*hw), GFP_KERNEL);
+	if (!hw)
+		return -ENOMEM;
+
+	hw->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(hw->clk))
+		return PTR_ERR(hw->clk);
+
+	ret = clk_prepare_enable(hw->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "Cannot enable clock\n");
+		return ret;
+	}
+
+	/* Disable soft reset */
+	hw->reset= devm_reset_control_get_exclusive(&pdev->dev, NULL);
+	if (IS_ERR(hw->reset)) {
+		clk_disable_unprepare(hw->clk);
+		return PTR_ERR(hw->reset);
+	}
+	reset_control_deassert(hw->reset);
+
+	ret = devm_add_action_or_reset(&pdev->dev, sun50i_hwpinlock_disable,
+				       hw);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to add hwspinlock disable action\n");
+		return ret;
+	}
+
+	num_locks = sun50i_get_num_locks(io_base);
+	if (!num_locks) {
+		dev_err(&pdev->dev, "Unrecognised sun50i hwspinlock device\n");
+		ret = -EINVAL;
+		goto out_reset;
+	}
+
+	hw->bank = devm_kzalloc(&pdev->dev,
+				struct_size(hw->bank, lock, num_locks),
+				GFP_KERNEL);
+	if (!hw) {
+		ret = -ENOMEM;
+		goto out_reset;
+	}
+
+	for (i = 0; i < num_locks; i++)
+		hw->bank.lock[i].priv = io_base + SPINLOCK_ID(i);
+
+	platform_set_drvdata(pdev, hw);
+
+	return devm_hwspin_lock_register(&pdev->dev, &hw->bank,
+					 &sun50i_hwspinlock_ops, 0, num_locks);
+}
+
+static int sun50i_hwspinlock_disable(struct platform_device *pdev)
+{
+	struct sun50i_hwspinlock *hw = platform_get_drvdata(pdev);
+	int ret;
+
+	reset_control_assert(hw->reset);
+	clk_disable_unprepare(hw->clk);
+
+	return 0;
+}
+
+static const struct of_device_id sun50i_hwpinlock_ids[] = {
+	{ .compatible = "allwinner,sun50i-a64-hwspinlock", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, sun50i_hwpinlock_ids);
+
+static struct platform_driver sun50i_hwspinlock_driver = {
+	.probe		= sun50i_hwspinlock_probe,
+	.driver		= {
+		.name	= "sun50i_hwspinlock",
+		.of_match_table = sun50i_hwpinlock_ids,
+	},
+};
+
+module_platform_driver(sun50i_hwspinlock_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Hardware spinlock driver for sun50i SoCs");
+MODULE_AUTHOR("Nikolay Borisov <nborisov@suse.com>");
-- 
2.17.1

[PATCH v2 2/3] arm64: dts: allwinner: a64: Add hwspinlock node

[Nikolay Borisov]

Add a node describing the hwspinlock on A64.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
index 27e48234f1c2..834f2f7f60bc 100644
--- a/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
+++ b/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
@@ -496,6 +496,15 @@
 			resets = <&ccu RST_BUS_CE>;
 		};
 
+		hwspinlock: spinlock@1c18000 {
+			compatible = "allwinner,sun50i-a64-hwspinlock";
+			reg = <0x01c18000 0x1000>;
+			clocks = <&ccu CLK_BUS_SPINLOCK>;
+			resets = <&ccu RST_BUS_SPINLOCK>;
+			#hwlock-cells = <1>;
+			status = "ok";
+		};
+
 		usb_otg: usb@1c19000 {
 			compatible = "allwinner,sun8i-a33-musb";
 			reg = <0x01c19000 0x0400>;
-- 
2.17.1

[PATCH v2 3/3] dt-bindings: hwlock: Document A64 hwspinlock bindings

[Nikolay Borisov]

Add binding for the hwspinlock found on Allwinner A64 SoC.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---
 .../allwinner,sun50i-a64-hwspinlock.yaml      | 47 +++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.yaml

diff --git a/Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.yaml b/Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.yaml
new file mode 100644
index 000000000000..46bfff2541d6
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.yaml
@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwlock/allwinner,sun50i-a64-hwspinlock.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Allwinner A64 SoC Hardware Spinlock bindings
+
+maintainers:
+  - Nikolay Borisov <nborisov@suse.com>
+
+properties:
+  "#hwlock-cells":
+    const: 1
+
+  compatible:
+    const: allwinner,sun50i-a64-hwspinlock
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+required:
+  - "#hwlock-cells"
+  - compatible
+  - reg
+  - clocks
+  - resets
+
+additionalProperties: false
+
+examples:
+  - |
+    hwspinlock@1c18000 {
+        compatible = "allwinner,sun50i-a64-hwspinlock";
+        #hwlock-cells = <1>;
+        reg = <0x01c18000 0x1000>;
+        clocks = <&ccu CLK_BUS_SPINLOCK>;
+        resets = <&ccu RST_BUS_SPINLOCK>;
+    };
+
+...
-- 
2.17.1

Re: [PATCH v2 3/3] dt-bindings: hwlock: Document A64 hwspinlock bindings

[Rob Herring]

On Tue, 11 Feb 2020 14:26:24 +0200, Nikolay Borisov wrote:
> Add binding for the hwspinlock found on Allwinner A64 SoC.
> 
> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> ---
>  .../allwinner,sun50i-a64-hwspinlock.yaml      | 47 +++++++++++++++++++
>  1 file changed, 47 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.yaml
> 

My bot found errors running 'make dt_binding_check' on your patch:

Documentation/devicetree/bindings/display/simple-framebuffer.example.dts:21.16-37.11: Warning (chosen_node_is_root): /example-0/chosen: chosen node must be at root node
Error: Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.example.dts:21.28-29 syntax error
FATAL ERROR: Unable to parse input tree
scripts/Makefile.lib:300: recipe for target 'Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.example.dt.yaml' failed
make[1]: *** [Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.example.dt.yaml] Error 1
Makefile:1263: recipe for target 'dt_binding_check' failed
make: *** [dt_binding_check] Error 2

See https://patchwork.ozlabs.org/patch/1236266
Please check and re-submit.

Re: [PATCH v2 3/3] dt-bindings: hwlock: Document A64 hwspinlock bindings

[Nikolay Borisov]

On 12.02.20 г. 4:00 ч., Rob Herring wrote:
> On Tue, 11 Feb 2020 14:26:24 +0200, Nikolay Borisov wrote:
>> Add binding for the hwspinlock found on Allwinner A64 SoC.
>>
>> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
>> ---
>>  .../allwinner,sun50i-a64-hwspinlock.yaml      | 47 +++++++++++++++++++
>>  1 file changed, 47 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.yaml
>>
> 
> My bot found errors running 'make dt_binding_check' on your patch:
> 
> Documentation/devicetree/bindings/display/simple-framebuffer.example.dts:21.16-37.11: Warning (chosen_node_is_root): /example-0/chosen: chosen node must be at root node
> Error: Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.example.dts:21.28-29 syntax error
> FATAL ERROR: Unable to parse input tree
> scripts/Makefile.lib:300: recipe for target 'Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.example.dt.yaml' failed
> make[1]: *** [Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.example.dt.yaml] Error 1
> Makefile:1263: recipe for target 'dt_binding_check' failed
> make: *** [dt_binding_check] Error 2
> 
> See https://patchwork.ozlabs.org/patch/1236266
> Please check and re-submit.
> 

I'm not able to build this schema at all:

make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- allmodconfig
make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- dt_binding_check DT_SCHEMA_FILES=Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.yaml

This results in a allwinner,sun50i-a64-hwspinlock.example.dts 
file and: 


make[1]: *** No rule to make target 'Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.example.dt.yaml', needed by '__build'.  Stop.
Makefile:1263: recipe for target 'dt_binding_check' failed

[PATCH v3] dt-bindings: hwlock: Document A64 hwspinlock bindings

[Nikolay Borisov]

Add binding for the hwspinlock found on Allwinner A64 SoC.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
---

V3: Added #include directive. This makes the patch pass schema validation.

 .../allwinner,sun50i-a64-hwspinlock.yaml      | 49 +++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.yaml

diff --git a/Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.yaml b/Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.yaml
new file mode 100644
index 000000000000..54270c8bb351
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwlock/allwinner,sun50i-a64-hwspinlock.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Allwinner A64 SoC Hardware Spinlock bindings
+
+maintainers:
+  - Nikolay Borisov <nborisov@suse.com>
+
+properties:
+  "#hwlock-cells":
+    const: 1
+
+  compatible:
+    const: allwinner,sun50i-a64-hwspinlock
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+required:
+  - "#hwlock-cells"
+  - compatible
+  - reg
+  - clocks
+  - resets
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/sun50i-a64-ccu.h>
+    #include <dt-bindings/reset/sun50i-a64-ccu.h>
+    hwspinlock@1c18000 {
+        compatible = "allwinner,sun50i-a64-hwspinlock";
+        #hwlock-cells = <1>;
+        reg = <0x01c18000 0x1000>;
+        clocks = <&ccu CLK_BUS_SPINLOCK>;
+        resets = <&ccu RST_BUS_SPINLOCK>;
+    };
+
+...
--
2.17.1

Re: [PATCH v3] dt-bindings: hwlock: Document A64 hwspinlock bindings

[Rob Herring]

On Wed, 12 Feb 2020 13:54:19 +0200, Nikolay Borisov wrote:
> Add binding for the hwspinlock found on Allwinner A64 SoC.
> 
> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> ---
> 
> V3: Added #include directive. This makes the patch pass schema validation.
> 
>  .../allwinner,sun50i-a64-hwspinlock.yaml      | 49 +++++++++++++++++++
>  1 file changed, 49 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/hwlock/allwinner,sun50i-a64-hwspinlock.yaml
> 

Reviewed-by: Rob Herring <robh@kernel.org>