regmap: Updates for v4.15

After several quiet kernel releases we've got a couple of new features
 in regmap, support for using hwspinlocks as the lock for the internal
 data structures and a helper for polling on regmap_fields.  The Kconfig
 dependencies on hwspinlocks were annoyingly difficult to squash between
 things behaving surprisingly and randconfig, I could've squashed those
 commits down but might've have caused hassle with other trees trying to
 use the new support.
 
  - Support for using a hwspinlock to protect the regmap.
  - An iopoll style helper for regmap_field.
 -----BEGIN PGP SIGNATURE-----
 
 iQFHBAABCgAxFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAloJkKUTHGJyb29uaWVA
 a2VybmVsLm9yZwAKCRAk1otyXVSH0Nr7B/9XaAdcoGg1FbcNeKrQN88VqGX8pU4W
 hcVMP4XdMxuBPmp/Rbkdkogvl8//MBGzn7jWnZBU59xkLnB0PfNB/JB5VdOrqT6w
 k+TdPNbs7s7cxTYubRBguhhEmC85gu2hiNCl+zlurPNBqHIhXXSVq+dNqlw4g4zI
 0cm0bTxSCLOppoBPXQXFxa4fAXopNPWeAF7Cg8+oMl6er8p7iILkxFK31JuafKjZ
 95RU0ikdmPHhV3OXrcE914hXnhFBM2VQ56z9BI84pwNONdRwWd10wRkoQ7zj4WDN
 qvNFY8mU/Bg6rHLI4Z2Ksj3zkLQs7VKBgdUL2dGPC/l3WElfFtF0sVkk
 =FBMj
 -----END PGP SIGNATURE-----

Merge tag 'regmap-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

Pull regmap updates from Mark Brown:
 "After several quiet kernel releases we've got a couple of new features
  in regmap, support for using hwspinlocks as the lock for the internal
  data structures and a helper for polling on regmap_fields. The Kconfig
  dependencies on hwspinlocks were annoyingly difficult to squash
  between things behaving surprisingly and randconfig, I could've
  squashed those commits down but might've have caused hassle with other
  trees trying to use the new support.

   - support for using a hwspinlock to protect the regmap

   - an iopoll style helper for regmap_field"

* tag 'regmap-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: Fix unused warning
  regmap: Try to work around Kconfig exploding on HWSPINLOCK
  regmap: Clean up hwspinlock on regmap exit
  regmap: Also protect hwspinlock in error handling path
  regmap: Add a config option for hwspinlock
  regmap: Add hardware spinlock support
  regmap: avoid -Wint-in-bool-context warning
  regmap: add iopoll-like polling macro for regmap_field
  regmap: constify regmap_bus structures
  regmap: Avoid namespace collision within macro & tidy up

drivers/base/regmap/Kconfig

@@ -6,6 +6,7 @@
 config REGMAP
 	default y if (REGMAP_I2C || REGMAP_SPI || REGMAP_SPMI || REGMAP_W1 || REGMAP_AC97 || REGMAP_MMIO || REGMAP_IRQ)
 	select IRQ_DOMAIN if REGMAP_IRQ
+	select REGMAP_HWSPINLOCK if HWSPINLOCK=y
 	bool
 
 config REGCACHE_COMPRESSED
@@ -37,3 +38,6 @@ config REGMAP_MMIO
 
 config REGMAP_IRQ
 	bool
+
+config REGMAP_HWSPINLOCK
+	bool

drivers/base/regmap/internal.h

@@ -157,6 +157,8 @@ struct regmap {
 
 	struct rb_root range_tree;
 	void *selector_work_buf;	/* Scratch buffer used for selector */
+
+	struct hwspinlock *hwlock;
 };
 
 struct regcache_ops {

drivers/base/regmap/regmap-spi.c

@@ -102,7 +102,7 @@ static int regmap_spi_read(void *context,
 	return spi_write_then_read(spi, reg, reg_size, val, val_size);
 }
 
-static struct regmap_bus regmap_spi = {
+static const struct regmap_bus regmap_spi = {
 	.write = regmap_spi_write,
 	.gather_write = regmap_spi_gather_write,
 	.async_write = regmap_spi_async_write,

drivers/base/regmap/regmap-spmi.c

@@ -83,7 +83,7 @@ static int regmap_spmi_base_write(void *context, const void *data,
 					     count - 1);
 }
 
-static struct regmap_bus regmap_spmi_base = {
+static const struct regmap_bus regmap_spmi_base = {
 	.read				= regmap_spmi_base_read,
 	.write				= regmap_spmi_base_write,
 	.gather_write			= regmap_spmi_base_gather_write,
@@ -203,7 +203,7 @@ static int regmap_spmi_ext_write(void *context, const void *data,
 					    count - 2);
 }
 
-static struct regmap_bus regmap_spmi_ext = {
+static const struct regmap_bus regmap_spmi_ext = {
 	.read				= regmap_spmi_ext_read,
 	.write				= regmap_spmi_ext_write,
 	.gather_write			= regmap_spmi_ext_gather_write,

drivers/base/regmap/regmap.c

@@ -20,6 +20,7 @@
 #include <linux/sched.h>
 #include <linux/delay.h>
 #include <linux/log2.h>
+#include <linux/hwspinlock.h>
 
 #define CREATE_TRACE_POINTS
 #include "trace.h"
@@ -413,6 +414,51 @@ static unsigned int regmap_parse_64_native(const void *buf)
 }
 #endif
 
+#ifdef REGMAP_HWSPINLOCK
+static void regmap_lock_hwlock(void *__map)
+{
+	struct regmap *map = __map;
+
+	hwspin_lock_timeout(map->hwlock, UINT_MAX);
+}
+
+static void regmap_lock_hwlock_irq(void *__map)
+{
+	struct regmap *map = __map;
+
+	hwspin_lock_timeout_irq(map->hwlock, UINT_MAX);
+}
+
+static void regmap_lock_hwlock_irqsave(void *__map)
+{
+	struct regmap *map = __map;
+
+	hwspin_lock_timeout_irqsave(map->hwlock, UINT_MAX,
+				    &map->spinlock_flags);
+}
+
+static void regmap_unlock_hwlock(void *__map)
+{
+	struct regmap *map = __map;
+
+	hwspin_unlock(map->hwlock);
+}
+
+static void regmap_unlock_hwlock_irq(void *__map)
+{
+	struct regmap *map = __map;
+
+	hwspin_unlock_irq(map->hwlock);
+}
+
+static void regmap_unlock_hwlock_irqrestore(void *__map)
+{
+	struct regmap *map = __map;
+
+	hwspin_unlock_irqrestore(map->hwlock, &map->spinlock_flags);
+}
+#endif
+
 static void regmap_lock_mutex(void *__map)
 {
 	struct regmap *map = __map;
@@ -627,6 +673,34 @@ struct regmap *__regmap_init(struct device *dev,
 		map->lock = config->lock;
 		map->unlock = config->unlock;
 		map->lock_arg = config->lock_arg;
+	} else if (config->hwlock_id) {
+#ifdef REGMAP_HWSPINLOCK
+		map->hwlock = hwspin_lock_request_specific(config->hwlock_id);
+		if (!map->hwlock) {
+			ret = -ENXIO;
+			goto err_map;
+		}
+
+		switch (config->hwlock_mode) {
+		case HWLOCK_IRQSTATE:
+			map->lock = regmap_lock_hwlock_irqsave;
+			map->unlock = regmap_unlock_hwlock_irqrestore;
+			break;
+		case HWLOCK_IRQ:
+			map->lock = regmap_lock_hwlock_irq;
+			map->unlock = regmap_unlock_hwlock_irq;
+			break;
+		default:
+			map->lock = regmap_lock_hwlock;
+			map->unlock = regmap_unlock_hwlock;
+			break;
+		}
+
+		map->lock_arg = map;
+#else
+		ret = -EINVAL;
+		goto err_map;
+#endif
 	} else {
 		if ((bus && bus->fast_io) ||
 		    config->fast_io) {
@@ -729,7 +803,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_write = regmap_format_2_6_write;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 
@@ -739,7 +813,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_write = regmap_format_4_12_write;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 
@@ -749,7 +823,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_write = regmap_format_7_9_write;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 
@@ -759,7 +833,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_write = regmap_format_10_14_write;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 
@@ -779,13 +853,13 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_reg = regmap_format_16_native;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 
 	case 24:
 		if (reg_endian != REGMAP_ENDIAN_BIG)
-			goto err_map;
+			goto err_hwlock;
 		map->format.format_reg = regmap_format_24;
 		break;
 
@@ -801,7 +875,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_reg = regmap_format_32_native;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 
@@ -818,13 +892,13 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.format_reg = regmap_format_64_native;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 #endif
 
 	default:
-		goto err_map;
+		goto err_hwlock;
 	}
 
 	if (val_endian == REGMAP_ENDIAN_NATIVE)
@@ -853,12 +927,12 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.parse_val = regmap_parse_16_native;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 	case 24:
 		if (val_endian != REGMAP_ENDIAN_BIG)
-			goto err_map;
+			goto err_hwlock;
 		map->format.format_val = regmap_format_24;
 		map->format.parse_val = regmap_parse_24;
 		break;
@@ -879,7 +953,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.parse_val = regmap_parse_32_native;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 #ifdef CONFIG_64BIT
@@ -900,7 +974,7 @@ struct regmap *__regmap_init(struct device *dev,
 			map->format.parse_val = regmap_parse_64_native;
 			break;
 		default:
-			goto err_map;
+			goto err_hwlock;
 		}
 		break;
 #endif
@@ -909,18 +983,18 @@ struct regmap *__regmap_init(struct device *dev,
 	if (map->format.format_write) {
 		if ((reg_endian != REGMAP_ENDIAN_BIG) ||
 		    (val_endian != REGMAP_ENDIAN_BIG))
-			goto err_map;
+			goto err_hwlock;
 		map->use_single_write = true;
 	}
 
 	if (!map->format.format_write &&
 	    !(map->format.format_reg && map->format.format_val))
-		goto err_map;
+		goto err_hwlock;
 
 	map->work_buf = kzalloc(map->format.buf_size, GFP_KERNEL);
 	if (map->work_buf == NULL) {
 		ret = -ENOMEM;
-		goto err_map;
+		goto err_hwlock;
 	}
 
 	if (map->format.format_write) {
@@ -1041,6 +1115,9 @@ err_regcache:
 err_range:
 	regmap_range_exit(map);
 	kfree(map->work_buf);
+err_hwlock:
+	if (IS_ENABLED(REGMAP_HWSPINLOCK) && map->hwlock)
+		hwspin_lock_free(map->hwlock);
 err_map:
 	kfree(map);
 err:
@@ -1228,6 +1305,8 @@ void regmap_exit(struct regmap *map)
 		kfree(async->work_buf);
 		kfree(async);
 	}
+	if (IS_ENABLED(REGMAP_HWSPINLOCK) && map->hwlock)
+		hwspin_lock_free(map->hwlock);
 	kfree(map);
 }
 EXPORT_SYMBOL_GPL(regmap_exit);