[PATCH 2/2] mfd: syscon: Add hardware spinlock support

[Baolin Wang]

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.w...@linaro.org>
---
 drivers/mfd/syscon.c |    9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
index b93fe4c..adc1c9c 100644
--- a/drivers/mfd/syscon.c
+++ b/drivers/mfd/syscon.c
@@ -25,6 +25,8 @@
 #include <linux/mfd/syscon.h>
 #include <linux/slab.h>
 
+#define SYSCON_HWSPINLOCK_TIMEOUT      (~0U)
+
 static struct platform_driver syscon_driver;
 
 static DEFINE_SPINLOCK(syscon_list_slock);
@@ -87,6 +89,13 @@ 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;
+               syscon_config.hwlock_timeout = SYSCON_HWSPINLOCK_TIMEOUT;
+       }
+
        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