regmap: Add hardware spinlock support
On some platforms, when reading or writing some special registers through
regmap, we should acquire one hardware spinlock to synchronize between
the multiple subsystems. Thus this patch adds the hardware spinlock
support for regmap.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 2a4435d..8641183 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -157,6 +157,8 @@
struct rb_root range_tree;
void *selector_work_buf; /* Scratch buffer used for selector */
+
+ struct hwspinlock *hwlock;
};
struct regcache_ops {
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index b9a779a..999e981 100644
--- a/drivers/base/regmap/regmap.c
+++ b/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 +414,49 @@
}
#endif
+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);
+}
+
static void regmap_lock_mutex(void *__map)
{
struct regmap *map = __map;
@@ -627,6 +671,29 @@
map->lock = config->lock;
map->unlock = config->unlock;
map->lock_arg = config->lock_arg;
+ } else if (config->hwlock_id) {
+ 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 {
if ((bus && bus->fast_io) ||
config->fast_io) {
@@ -729,7 +796,7 @@
map->format.format_write = regmap_format_2_6_write;
break;
default:
- goto err_map;
+ goto err_hwlock;
}
break;
@@ -739,7 +806,7 @@
map->format.format_write = regmap_format_4_12_write;
break;
default:
- goto err_map;
+ goto err_hwlock;
}
break;
@@ -749,7 +816,7 @@
map->format.format_write = regmap_format_7_9_write;
break;
default:
- goto err_map;
+ goto err_hwlock;
}
break;
@@ -759,7 +826,7 @@
map->format.format_write = regmap_format_10_14_write;
break;
default:
- goto err_map;
+ goto err_hwlock;
}
break;
@@ -779,13 +846,13 @@
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 +868,7 @@
map->format.format_reg = regmap_format_32_native;
break;
default:
- goto err_map;
+ goto err_hwlock;
}
break;
@@ -818,13 +885,13 @@
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 +920,12 @@
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 +946,7 @@
map->format.parse_val = regmap_parse_32_native;
break;
default:
- goto err_map;
+ goto err_hwlock;
}
break;
#ifdef CONFIG_64BIT
@@ -900,7 +967,7 @@
map->format.parse_val = regmap_parse_64_native;
break;
default:
- goto err_map;
+ goto err_hwlock;
}
break;
#endif
@@ -909,18 +976,18 @@
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 +1108,8 @@
err_range:
regmap_range_exit(map);
kfree(map->work_buf);
+err_hwlock:
+ hwspin_lock_free(map->hwlock);
err_map:
kfree(map);
err:
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 978abfb..edc32aa 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -273,6 +273,9 @@
*
* @ranges: Array of configuration entries for virtual address ranges.
* @num_ranges: Number of range configuration entries.
+ * @hwlock_id: Specify the hardware spinlock id.
+ * @hwlock_mode: The hardware spinlock mode, should be HWLOCK_IRQSTATE,
+ * HWLOCK_IRQ or 0.
*/
struct regmap_config {
const char *name;
@@ -317,6 +320,9 @@
const struct regmap_range_cfg *ranges;
unsigned int num_ranges;
+
+ unsigned int hwlock_id;
+ unsigned int hwlock_mode;
};
/**
