diff mbox series

[v4] mfd: syscon: Add hardware spinlock support

Message ID 2344ec4123c8b0985e54e03a0fa1bfe8d5e68235.1512009343.git.baolin.wang@linaro.org
State New
Headers show
Series [v4] mfd: syscon: Add hardware spinlock support | expand

Commit Message

(Exiting) Baolin Wang Nov. 30, 2017, 2:38 a.m. UTC
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 <baolin.wang@linaro.org>

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

---
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 |    1 +
 drivers/mfd/syscon.c                             |   21 +++++++++++++++++++++
 2 files changed, 22 insertions(+)

-- 
1.7.9.5

Comments

Lee Jones Nov. 30, 2017, 8:35 a.m. UTC | #1
On Thu, 30 Nov 2017, Baolin Wang wrote:

> 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 <baolin.wang@linaro.org>

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

> ---

> 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 |    1 +

>  drivers/mfd/syscon.c                             |   21 +++++++++++++++++++++

>  2 files changed, 22 insertions(+)

> 

> diff --git a/Documentation/devicetree/bindings/mfd/syscon.txt b/Documentation/devicetree/bindings/mfd/syscon.txt

> index 8b92d45..f464cc8 100644

> --- a/Documentation/devicetree/bindings/mfd/syscon.txt

> +++ b/Documentation/devicetree/bindings/mfd/syscon.txt

> @@ -16,6 +16,7 @@ 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.


Example?

Perhaps even include the hwlock node (I'm not sure what that would
look like).

>  Examples:

>  gpr: iomuxc-gpr@20e0000 {

> diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c

> index b93fe4c..caf6a25 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 */


Is your shift key broken? ;)

Please use proper grammar.  Sentences start with capital letters.

> +			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;


-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/mfd/syscon.txt b/Documentation/devicetree/bindings/mfd/syscon.txt
index 8b92d45..f464cc8 100644
--- a/Documentation/devicetree/bindings/mfd/syscon.txt
+++ b/Documentation/devicetree/bindings/mfd/syscon.txt
@@ -16,6 +16,7 @@  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 {
diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
index b93fe4c..caf6a25 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;