v4.19.13 snapshot.
diff --git a/sound/soc/soc-io.c b/sound/soc/soc-io.c
new file mode 100644
index 0000000..1ff9175
--- /dev/null
+++ b/sound/soc/soc-io.c
@@ -0,0 +1,202 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// soc-io.c -- ASoC register I/O helpers
+//
+// Copyright 2009-2011 Wolfson Microelectronics PLC.
+//
+// Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+
+#include <linux/i2c.h>
+#include <linux/spi/spi.h>
+#include <linux/regmap.h>
+#include <linux/export.h>
+#include <sound/soc.h>
+
+/**
+ * snd_soc_component_read() - Read register value
+ * @component: Component to read from
+ * @reg: Register to read
+ * @val: Pointer to where the read value is stored
+ *
+ * Return: 0 on success, a negative error code otherwise.
+ */
+int snd_soc_component_read(struct snd_soc_component *component,
+ unsigned int reg, unsigned int *val)
+{
+ int ret;
+
+ if (component->regmap)
+ ret = regmap_read(component->regmap, reg, val);
+ else if (component->driver->read) {
+ *val = component->driver->read(component, reg);
+ ret = 0;
+ }
+ else
+ ret = -EIO;
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(snd_soc_component_read);
+
+unsigned int snd_soc_component_read32(struct snd_soc_component *component,
+ unsigned int reg)
+{
+ unsigned int val;
+ int ret;
+
+ ret = snd_soc_component_read(component, reg, &val);
+ if (ret < 0)
+ return -1;
+
+ return val;
+}
+EXPORT_SYMBOL_GPL(snd_soc_component_read32);
+
+/**
+ * snd_soc_component_write() - Write register value
+ * @component: Component to write to
+ * @reg: Register to write
+ * @val: Value to write to the register
+ *
+ * Return: 0 on success, a negative error code otherwise.
+ */
+int snd_soc_component_write(struct snd_soc_component *component,
+ unsigned int reg, unsigned int val)
+{
+ if (component->regmap)
+ return regmap_write(component->regmap, reg, val);
+ else if (component->driver->write)
+ return component->driver->write(component, reg, val);
+ else
+ return -EIO;
+}
+EXPORT_SYMBOL_GPL(snd_soc_component_write);
+
+static int snd_soc_component_update_bits_legacy(
+ struct snd_soc_component *component, unsigned int reg,
+ unsigned int mask, unsigned int val, bool *change)
+{
+ unsigned int old, new;
+ int ret;
+
+ mutex_lock(&component->io_mutex);
+
+ ret = snd_soc_component_read(component, reg, &old);
+ if (ret < 0)
+ goto out_unlock;
+
+ new = (old & ~mask) | (val & mask);
+ *change = old != new;
+ if (*change)
+ ret = snd_soc_component_write(component, reg, new);
+out_unlock:
+ mutex_unlock(&component->io_mutex);
+
+ return ret;
+}
+
+/**
+ * snd_soc_component_update_bits() - Perform read/modify/write cycle
+ * @component: Component to update
+ * @reg: Register to update
+ * @mask: Mask that specifies which bits to update
+ * @val: New value for the bits specified by mask
+ *
+ * Return: 1 if the operation was successful and the value of the register
+ * changed, 0 if the operation was successful, but the value did not change.
+ * Returns a negative error code otherwise.
+ */
+int snd_soc_component_update_bits(struct snd_soc_component *component,
+ unsigned int reg, unsigned int mask, unsigned int val)
+{
+ bool change;
+ int ret;
+
+ if (component->regmap)
+ ret = regmap_update_bits_check(component->regmap, reg, mask,
+ val, &change);
+ else
+ ret = snd_soc_component_update_bits_legacy(component, reg,
+ mask, val, &change);
+
+ if (ret < 0)
+ return ret;
+ return change;
+}
+EXPORT_SYMBOL_GPL(snd_soc_component_update_bits);
+
+/**
+ * snd_soc_component_update_bits_async() - Perform asynchronous
+ * read/modify/write cycle
+ * @component: Component to update
+ * @reg: Register to update
+ * @mask: Mask that specifies which bits to update
+ * @val: New value for the bits specified by mask
+ *
+ * This function is similar to snd_soc_component_update_bits(), but the update
+ * operation is scheduled asynchronously. This means it may not be completed
+ * when the function returns. To make sure that all scheduled updates have been
+ * completed snd_soc_component_async_complete() must be called.
+ *
+ * Return: 1 if the operation was successful and the value of the register
+ * changed, 0 if the operation was successful, but the value did not change.
+ * Returns a negative error code otherwise.
+ */
+int snd_soc_component_update_bits_async(struct snd_soc_component *component,
+ unsigned int reg, unsigned int mask, unsigned int val)
+{
+ bool change;
+ int ret;
+
+ if (component->regmap)
+ ret = regmap_update_bits_check_async(component->regmap, reg,
+ mask, val, &change);
+ else
+ ret = snd_soc_component_update_bits_legacy(component, reg,
+ mask, val, &change);
+
+ if (ret < 0)
+ return ret;
+ return change;
+}
+EXPORT_SYMBOL_GPL(snd_soc_component_update_bits_async);
+
+/**
+ * snd_soc_component_async_complete() - Ensure asynchronous I/O has completed
+ * @component: Component for which to wait
+ *
+ * This function blocks until all asynchronous I/O which has previously been
+ * scheduled using snd_soc_component_update_bits_async() has completed.
+ */
+void snd_soc_component_async_complete(struct snd_soc_component *component)
+{
+ if (component->regmap)
+ regmap_async_complete(component->regmap);
+}
+EXPORT_SYMBOL_GPL(snd_soc_component_async_complete);
+
+/**
+ * snd_soc_component_test_bits - Test register for change
+ * @component: component
+ * @reg: Register to test
+ * @mask: Mask that specifies which bits to test
+ * @value: Value to test against
+ *
+ * Tests a register with a new value and checks if the new value is
+ * different from the old value.
+ *
+ * Return: 1 for change, otherwise 0.
+ */
+int snd_soc_component_test_bits(struct snd_soc_component *component,
+ unsigned int reg, unsigned int mask, unsigned int value)
+{
+ unsigned int old, new;
+ int ret;
+
+ ret = snd_soc_component_read(component, reg, &old);
+ if (ret < 0)
+ return ret;
+ new = (old & ~mask) | value;
+ return old != new;
+}
+EXPORT_SYMBOL_GPL(snd_soc_component_test_bits);