[PATCH 1/5] firmware: cs_dsp: Add locked wrappers for coeff read and write

[Richard Fitzgerald <rf@xxxxxxxxxxxxxxxxxxxxx>]

From: Simon Trimmer <simont@xxxxxxxxxxxxxxxxxxxxx>

It is a common pattern for functions to take and release the DSP
pwr_lock over the cs_dsp calls to read and write firmware controls.
Add wrapper functions to do this sequence so that the calling code can
be simplified to a single function call..

Signed-off-by: Simon Trimmer <simont@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Richard Fitzgerald <rf@xxxxxxxxxxxxxxxxxxxxx>
---
 drivers/firmware/cirrus/cs_dsp.c       | 54 ++++++++++++++++++++++++++
 include/linux/firmware/cirrus/cs_dsp.h |  4 ++
 2 files changed, 58 insertions(+)

diff --git a/drivers/firmware/cirrus/cs_dsp.c b/drivers/firmware/cirrus/cs_dsp.c
index 9f3d665cfdcf..0d139e4de37c 100644
--- a/drivers/firmware/cirrus/cs_dsp.c
+++ b/drivers/firmware/cirrus/cs_dsp.c
@@ -819,6 +819,33 @@ int cs_dsp_coeff_write_ctrl(struct cs_dsp_coeff_ctl *ctl,
 }
 EXPORT_SYMBOL_NS_GPL(cs_dsp_coeff_write_ctrl, FW_CS_DSP);
 
+/**
+ * cs_dsp_coeff_lock_and_write_ctrl() - Writes the given buffer to the given coefficient control
+ * @ctl: pointer to coefficient control
+ * @off: word offset at which data should be written
+ * @buf: the buffer to write to the given control
+ * @len: the length of the buffer in bytes
+ *
+ * Same as cs_dsp_coeff_write_ctrl() but takes pwr_lock.
+ *
+ * Return: A negative number on error, 1 when the control value changed and 0 when it has not.
+ */
+int cs_dsp_coeff_lock_and_write_ctrl(struct cs_dsp_coeff_ctl *ctl,
+				     unsigned int off, const void *buf, size_t len)
+{
+	struct cs_dsp *dsp = ctl->dsp;
+	int ret;
+
+	lockdep_assert_not_held(&dsp->pwr_lock);
+
+	mutex_lock(&dsp->pwr_lock);
+	ret = cs_dsp_coeff_write_ctrl(ctl, off, buf, len);
+	mutex_unlock(&dsp->pwr_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cs_dsp_coeff_lock_and_write_ctrl);
+
 static int cs_dsp_coeff_read_ctrl_raw(struct cs_dsp_coeff_ctl *ctl,
 				      unsigned int off, void *buf, size_t len)
 {
@@ -891,6 +918,33 @@ int cs_dsp_coeff_read_ctrl(struct cs_dsp_coeff_ctl *ctl,
 }
 EXPORT_SYMBOL_NS_GPL(cs_dsp_coeff_read_ctrl, FW_CS_DSP);
 
+/**
+ * cs_dsp_coeff_lock_and_read_ctrl() - Reads the given coefficient control into the given buffer
+ * @ctl: pointer to coefficient control
+ * @off: word offset at which data should be read
+ * @buf: the buffer to store to the given control
+ * @len: the length of the buffer in bytes
+ *
+ * Same as cs_dsp_coeff_read_ctrl() but takes pwr_lock.
+ *
+ * Return: Zero for success, a negative number on error.
+ */
+int cs_dsp_coeff_lock_and_read_ctrl(struct cs_dsp_coeff_ctl *ctl,
+				    unsigned int off, void *buf, size_t len)
+{
+	struct cs_dsp *dsp = ctl->dsp;
+	int ret;
+
+	lockdep_assert_not_held(&dsp->pwr_lock);
+
+	mutex_lock(&dsp->pwr_lock);
+	ret = cs_dsp_coeff_read_ctrl(ctl, off, buf, len);
+	mutex_unlock(&dsp->pwr_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(cs_dsp_coeff_lock_and_read_ctrl);
+
 static int cs_dsp_coeff_init_control_caches(struct cs_dsp *dsp)
 {
 	struct cs_dsp_coeff_ctl *ctl;
diff --git a/include/linux/firmware/cirrus/cs_dsp.h b/include/linux/firmware/cirrus/cs_dsp.h
index 23384a54d575..82687e07a7c2 100644
--- a/include/linux/firmware/cirrus/cs_dsp.h
+++ b/include/linux/firmware/cirrus/cs_dsp.h
@@ -238,8 +238,12 @@ void cs_dsp_cleanup_debugfs(struct cs_dsp *dsp);
 int cs_dsp_coeff_write_acked_control(struct cs_dsp_coeff_ctl *ctl, unsigned int event_id);
 int cs_dsp_coeff_write_ctrl(struct cs_dsp_coeff_ctl *ctl, unsigned int off,
 			    const void *buf, size_t len);
+int cs_dsp_coeff_lock_and_write_ctrl(struct cs_dsp_coeff_ctl *ctl, unsigned int off,
+				     const void *buf, size_t len);
 int cs_dsp_coeff_read_ctrl(struct cs_dsp_coeff_ctl *ctl, unsigned int off,
 			   void *buf, size_t len);
+int cs_dsp_coeff_lock_and_read_ctrl(struct cs_dsp_coeff_ctl *ctl, unsigned int off,
+				    void *buf, size_t len);
 struct cs_dsp_coeff_ctl *cs_dsp_get_ctl(struct cs_dsp *dsp, const char *name, int type,
 					unsigned int alg);
 
-- 
2.39.2