mfd: syscon: Add hardware spinlock support
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>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
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;