Merge tag 'regmap-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

Pull regmap updates from Mark Brown:
 "A very busy release for regmap, all fairly specialist stuff but
  useful:

   - Support for disabling locking from Bartosz Golaszewski, allowing
     users that handle their own locking to save some overhead.

   - Support for hwspinlocks in syscons in MFD from Baolin Wang, this is
     going through the regmap tree since the first users turned up some
     some cases that needed interface tweaks with 0 being used as a
     syscon identifier.

   - Support for devices with no read or write flag from Andrew F.
     Davis.

   - Basic support for devices on SoundWire buses from Vinod Koul"

* tag 'regmap-v4.16' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  mfd: syscon: Add hardware spinlock support
  regmap: Allow empty read/write_flag_mask
  regcache: flat: Un-inline index lookup from cache access
  regmap: Add SoundWire bus support
  regmap: Add one flag to indicate if a hwlock should be used
  regmap: debugfs: document why we don't create the debugfs entries
  regmap: debugfs: emit a debug message when locking is disabled
  regmap: use proper part of work_buf for storing val
  regmap: potentially duplicate the name string stored in regmap
  regmap: Disable debugfs when locking is disabled
  regmap: rename regmap_lock_unlock_empty() to regmap_lock_unlock_none()
  regmap: allow to disable all locking mechanisms
  regmap: Remove the redundant config to select hwspinlock

1 files changed, 19 insertions, 0 deletions

diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
index b93fe4c4957a..7eaa40bc703f 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;