[PATCH v5] mfd: syscon: Add hardware spinlock support
From: Baolin Wang <hidden>
Date: 2017-11-30 09:11:27
Also in:
lkml
Subsystem:
multifunction devices (mfd), open firmware and flattened device tree bindings, system configuration (syscon), the rest · Maintainers:
Lee Jones, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Arnd Bergmann, Linus Torvalds
Some system control registers need hardware spinlock to synchronize between the multiple subsystems, so we should add hardware spinlock support for syscon. Signed-off-by: Baolin Wang <redacted> Acked-by: Rob Herring <redacted> --- Changes since v4: - Add one exapmle to show how to add hwlock. - Fix the coding style issue. Changes since v3: - Add error handling for of_hwspin_lock_get_id() Changes since v2: - Add acked tag from Rob. Changes since v1: - Remove timeout configuration. - Modify the binding file to add hwlocks. --- Documentation/devicetree/bindings/mfd/syscon.txt | 8 ++++++++ drivers/mfd/syscon.c | 21 +++++++++++++++++++++ 2 files changed, 29 insertions(+)
diff --git a/Documentation/devicetree/bindings/mfd/syscon.txt b/Documentation/devicetree/bindings/mfd/syscon.txt
index 8b92d45..25d9e9c 100644
--- a/Documentation/devicetree/bindings/mfd/syscon.txt
+++ b/Documentation/devicetree/bindings/mfd/syscon.txt@@ -16,9 +16,17 @@ Required properties: Optional property: - reg-io-width: the size (in bytes) of the IO accesses that should be performed on the device. +- hwlocks: reference to a phandle of a hardware spinlock provider node. Examples: gpr: iomuxc-gpr@20e0000 { compatible = "fsl,imx6q-iomuxc-gpr", "syscon"; reg = <0x020e0000 0x38>; + hwlocks = <&hwlock1 1>; +}; + +hwlock1: hwspinlock@40500000 { + ... + reg = <0x40500000 0x1000>; + #hwlock-cells = <1>; };
diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
index b93fe4c..5b67dbc 100644
--- a/drivers/mfd/syscon.c
+++ b/drivers/mfd/syscon.c@@ -13,6 +13,7 @@ */ #include <linux/err.h> +#include <linux/hwspinlock.h> #include <linux/io.h> #include <linux/module.h> #include <linux/list.h>
@@ -87,6 +88,26 @@ static struct syscon *of_syscon_register(struct device_node *np) if (ret) reg_io_width = 4; + ret = of_hwspin_lock_get_id(np, 0); + if (ret > 0) { + syscon_config.hwlock_id = ret; + syscon_config.hwlock_mode = HWLOCK_IRQSTATE; + } else { + switch (ret) { + case -ENOENT: + /* Ignore missing hwlock, it's optional. */ + break; + case 0: + ret = -EINVAL; + /* fall-through */ + default: + pr_err("Failed to retrieve valid hwlock: %d\n", ret); + /* fall-through */ + case -EPROBE_DEFER: + goto err_regmap; + } + } + syscon_config.reg_stride = reg_io_width; syscon_config.val_bits = reg_io_width * 8; syscon_config.max_register = resource_size(&res) - reg_io_width;
--
1.7.9.5
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