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-rw-r--r--Documentation/devicetree/bindings/mfd/syscon.txt8
-rw-r--r--drivers/base/regmap/Kconfig4
-rw-r--r--drivers/base/regmap/internal.h8
-rw-r--r--drivers/base/regmap/regcache-flat.c15
-rw-r--r--drivers/base/regmap/regmap-debugfs.c12
-rw-r--r--drivers/base/regmap/regmap.c37
-rw-r--r--drivers/mfd/syscon.c19
-rw-r--r--include/linux/regmap.h7
8 files changed, 88 insertions, 22 deletions
diff --git a/Documentation/devicetree/bindings/mfd/syscon.txt b/Documentation/devicetree/bindings/mfd/syscon.txt
index 8b92d4576c42..25d9e9c2fd53 100644
--- a/Documentation/devicetree/bindings/mfd/syscon.txt
+++ b/Documentation/devicetree/bindings/mfd/syscon.txt
@@ -16,9 +16,17 @@ Required properties:
Optional property:
- reg-io-width: the size (in bytes) of the IO accesses that should be
performed on the device.
+- hwlocks: reference to a phandle of a hardware spinlock provider node.
Examples:
gpr: iomuxc-gpr@20e0000 {
compatible = "fsl,imx6q-iomuxc-gpr", "syscon";
reg = <0x020e0000 0x38>;
+ hwlocks = <&hwlock1 1>;
+};
+
+hwlock1: hwspinlock@40500000 {
+ ...
+ reg = <0x40500000 0x1000>;
+ #hwlock-cells = <1>;
};
diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig
index 3a1535d812d8..0368fd7b3a41 100644
--- a/drivers/base/regmap/Kconfig
+++ b/drivers/base/regmap/Kconfig
@@ -6,7 +6,6 @@
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
@@ -38,6 +37,3 @@ config REGMAP_MMIO
config REGMAP_IRQ
bool
-
-config REGMAP_HWSPINLOCK
- bool
diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 8641183cac2f..53785e0e297a 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -77,6 +77,7 @@ struct regmap {
int async_ret;
#ifdef CONFIG_DEBUG_FS
+ bool debugfs_disable;
struct dentry *debugfs;
const char *debugfs_name;
@@ -215,10 +216,17 @@ struct regmap_field {
extern void regmap_debugfs_initcall(void);
extern void regmap_debugfs_init(struct regmap *map, const char *name);
extern void regmap_debugfs_exit(struct regmap *map);
+
+static inline void regmap_debugfs_disable(struct regmap *map)
+{
+ map->debugfs_disable = true;
+}
+
#else
static inline void regmap_debugfs_initcall(void) { }
static inline void regmap_debugfs_init(struct regmap *map, const char *name) { }
static inline void regmap_debugfs_exit(struct regmap *map) { }
+static inline void regmap_debugfs_disable(struct regmap *map) { }
#endif
/* regcache core declarations */
diff --git a/drivers/base/regmap/regcache-flat.c b/drivers/base/regmap/regcache-flat.c
index 4d2e50bfc726..bc6cd88b8cc6 100644
--- a/drivers/base/regmap/regcache-flat.c
+++ b/drivers/base/regmap/regcache-flat.c
@@ -37,9 +37,12 @@ static int regcache_flat_init(struct regmap *map)
cache = map->cache;
- for (i = 0; i < map->num_reg_defaults; i++)
- cache[regcache_flat_get_index(map, map->reg_defaults[i].reg)] =
- map->reg_defaults[i].def;
+ for (i = 0; i < map->num_reg_defaults; i++) {
+ unsigned int reg = map->reg_defaults[i].reg;
+ unsigned int index = regcache_flat_get_index(map, reg);
+
+ cache[index] = map->reg_defaults[i].def;
+ }
return 0;
}
@@ -56,8 +59,9 @@ static int regcache_flat_read(struct regmap *map,
unsigned int reg, unsigned int *value)
{
unsigned int *cache = map->cache;
+ unsigned int index = regcache_flat_get_index(map, reg);
- *value = cache[regcache_flat_get_index(map, reg)];
+ *value = cache[index];
return 0;
}
@@ -66,8 +70,9 @@ static int regcache_flat_write(struct regmap *map, unsigned int reg,
unsigned int value)
{
unsigned int *cache = map->cache;
+ unsigned int index = regcache_flat_get_index(map, reg);
- cache[regcache_flat_get_index(map, reg)] = value;
+ cache[index] = value;
return 0;
}
diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c
index 36ce3511c733..f3266334063e 100644
--- a/drivers/base/regmap/regmap-debugfs.c
+++ b/drivers/base/regmap/regmap-debugfs.c
@@ -529,6 +529,18 @@ void regmap_debugfs_init(struct regmap *map, const char *name)
struct regmap_range_node *range_node;
const char *devname = "dummy";
+ /*
+ * Userspace can initiate reads from the hardware over debugfs.
+ * Normally internal regmap structures and buffers are protected with
+ * a mutex or a spinlock, but if the regmap owner decided to disable
+ * all locking mechanisms, this is no longer the case. For safety:
+ * don't create the debugfs entries if locking is disabled.
+ */
+ if (map->debugfs_disable) {
+ dev_dbg(map->dev, "regmap locking disabled - not creating debugfs entries\n");
+ return;
+ }
+
/* If we don't have the debugfs root yet, postpone init */
if (!regmap_debugfs_root) {
struct regmap_debugfs_node *node;
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 9fb3a792642b..be55e5a0e38c 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -414,7 +414,6 @@ 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;
@@ -457,7 +456,11 @@ static void regmap_unlock_hwlock_irqrestore(void *__map)
hwspin_unlock_irqrestore(map->hwlock, &map->spinlock_flags);
}
-#endif
+
+static void regmap_lock_unlock_none(void *__map)
+{
+
+}
static void regmap_lock_mutex(void *__map)
{
@@ -669,16 +672,26 @@ struct regmap *__regmap_init(struct device *dev,
goto err;
}
- if (config->lock && config->unlock) {
+ if (config->name) {
+ map->name = kstrdup_const(config->name, GFP_KERNEL);
+ if (!map->name) {
+ ret = -ENOMEM;
+ goto err_map;
+ }
+ }
+
+ if (config->disable_locking) {
+ map->lock = map->unlock = regmap_lock_unlock_none;
+ regmap_debugfs_disable(map);
+ } else if (config->lock && config->unlock) {
map->lock = config->lock;
map->unlock = config->unlock;
map->lock_arg = config->lock_arg;
- } else if (config->hwlock_id) {
-#ifdef REGMAP_HWSPINLOCK
+ } else if (config->use_hwlock) {
map->hwlock = hwspin_lock_request_specific(config->hwlock_id);
if (!map->hwlock) {
ret = -ENXIO;
- goto err_map;
+ goto err_name;
}
switch (config->hwlock_mode) {
@@ -697,10 +710,6 @@ struct regmap *__regmap_init(struct device *dev,
}
map->lock_arg = map;
-#else
- ret = -EINVAL;
- goto err_map;
-#endif
} else {
if ((bus && bus->fast_io) ||
config->fast_io) {
@@ -762,7 +771,6 @@ struct regmap *__regmap_init(struct device *dev,
map->volatile_reg = config->volatile_reg;
map->precious_reg = config->precious_reg;
map->cache_type = config->cache_type;
- map->name = config->name;
spin_lock_init(&map->async_lock);
INIT_LIST_HEAD(&map->async_list);
@@ -1116,8 +1124,10 @@ err_range:
regmap_range_exit(map);
kfree(map->work_buf);
err_hwlock:
- if (IS_ENABLED(REGMAP_HWSPINLOCK) && map->hwlock)
+ if (map->hwlock)
hwspin_lock_free(map->hwlock);
+err_name:
+ kfree_const(map->name);
err_map:
kfree(map);
err:
@@ -1305,8 +1315,9 @@ void regmap_exit(struct regmap *map)
kfree(async->work_buf);
kfree(async);
}
- if (IS_ENABLED(REGMAP_HWSPINLOCK) && map->hwlock)
+ if (map->hwlock)
hwspin_lock_free(map->hwlock);
+ kfree_const(map->name);
kfree(map);
}
EXPORT_SYMBOL_GPL(regmap_exit);
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;
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 15eddc1353ba..671515911b03 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -264,6 +264,9 @@ typedef void (*regmap_unlock)(void *);
* field is NULL but precious_table (see below) is not, the
* check is performed on such table (a register is precious if
* it belongs to one of the ranges specified by precious_table).
+ * @disable_locking: This regmap is either protected by external means or
+ * is guaranteed not be be accessed from multiple threads.
+ * Don't use any locking mechanisms.
* @lock: Optional lock callback (overrides regmap's default lock
* function, based on spinlock or mutex).
* @unlock: As above for unlocking.
@@ -317,6 +320,7 @@ typedef void (*regmap_unlock)(void *);
*
* @ranges: Array of configuration entries for virtual address ranges.
* @num_ranges: Number of range configuration entries.
+ * @use_hwlock: Indicate if a hardware spinlock should be used.
* @hwlock_id: Specify the hardware spinlock id.
* @hwlock_mode: The hardware spinlock mode, should be HWLOCK_IRQSTATE,
* HWLOCK_IRQ or 0.
@@ -333,6 +337,8 @@ struct regmap_config {
bool (*readable_reg)(struct device *dev, unsigned int reg);
bool (*volatile_reg)(struct device *dev, unsigned int reg);
bool (*precious_reg)(struct device *dev, unsigned int reg);
+
+ bool disable_locking;
regmap_lock lock;
regmap_unlock unlock;
void *lock_arg;
@@ -365,6 +371,7 @@ struct regmap_config {
const struct regmap_range_cfg *ranges;
unsigned int num_ranges;
+ bool use_hwlock;
unsigned int hwlock_id;
unsigned int hwlock_mode;
};
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-14 01:55:57 +0100