Hi Arnd,
On 2 January 2018 at 23:36, Lee Jones <lee.jones@xxxxxxxxxx> wrote:
> Arnd,
>
>> 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@xxxxxxxxxx>
>> Acked-by: Rob Herring <robh@xxxxxxxxxx>
>
> ... did you sign off on this in the end?
>
Could you apply this patch if there are no other issue? Thanks.
>> ---
>> Changes since v6:
>> - Treat hwlock id 0 as valid for regmap.
>>
>> Changes since v5:
>> - Fix the case that hwspinlock is not enabled.
>>
>> 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 | 19 +++++++++++++++++++
>> 2 files changed, 27 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..7eaa40b 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 +88,24 @@ 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 || (IS_ENABLED(CONFIG_HWSPINLOCK) && ret == 0)) {
>> + syscon_config.use_hwlock = true;
>> + syscon_config.hwlock_id = ret;
>> + syscon_config.hwlock_mode = HWLOCK_IRQSTATE;
>> + } else if (ret < 0) {
>> + switch (ret) {
>> + case -ENOENT:
>> + /* Ignore missing hwlock, it's optional. */
>> + break;
>> + 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 Services Technical Lead
> Linaro.org │ Open source software for ARM SoCs
> Follow Linaro: Facebook | Twitter | Blog
--
Baolin.wang
Best Regards
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