firmware: cs_dsp: Factor out common debugfs string read

cs_dsp_debugfs_wmfw_read() and cs_dsp_debugfs_bin_read() were identical
except for which struct member they printed. Move all this duplicated
code into a common function cs_dsp_debugfs_string_read().

The check for dsp->booted has been removed because this is redundant.
The two strings are set when the DSP is booted and cleared when the
DSP is powered-down.

Access to the string char * must be protected by the pwr_lock mutex. The
string is passed into cs_dsp_debugfs_string_read() as a pointer to the
char * so that the mutex lock can also be factored out into
cs_dsp_debugfs_string_read().

wmfw_file_name and bin_file_name members of struct cs_dsp have been
changed to const char *. It makes for a better API to pass a const
pointer into cs_dsp_debugfs_string_read().

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://patch.msgid.link/20251120130640.1169780-2-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/firmware/cirrus/cs_dsp.c b/drivers/firmware/cirrus/cs_dsp.c
index f51047d8ea64f571bbf55f6317460287200bc5ce..58e41751dbc19b0020e7acaaaedfc63ecfb6b2b6 100644 (file)
--- a/drivers/firmware/cirrus/cs_dsp.c
+++ b/drivers/firmware/cirrus/cs_dsp.c
@@ -9,6 +9,7 @@
  *                         Cirrus Logic International Semiconductor Ltd.
  */
 
+#include <linux/cleanup.h>
 #include <linux/ctype.h>
 #include <linux/debugfs.h>
 #include <linux/delay.h>
@@ -410,24 +411,30 @@ static void cs_dsp_debugfs_clear(struct cs_dsp *dsp)
        dsp->bin_file_name = NULL;
 }
 
+static ssize_t cs_dsp_debugfs_string_read(struct cs_dsp *dsp,
+                                         char __user *user_buf,
+                                         size_t count, loff_t *ppos,
+                                         const char **pstr)
+{
+       const char *str;
+
+       scoped_guard(mutex, &dsp->pwr_lock) {
+               str = *pstr;
+               if (!str)
+                       return 0;
+
+               return simple_read_from_buffer(user_buf, count, ppos, str, strlen(str));
+       }
+}
+
 static ssize_t cs_dsp_debugfs_wmfw_read(struct file *file,
                                        char __user *user_buf,
                                        size_t count, loff_t *ppos)
 {
        struct cs_dsp *dsp = file->private_data;
-       ssize_t ret;
 
-       mutex_lock(&dsp->pwr_lock);
-
-       if (!dsp->wmfw_file_name || !dsp->booted)
-               ret = 0;
-       else
-               ret = simple_read_from_buffer(user_buf, count, ppos,
-                                             dsp->wmfw_file_name,
-                                             strlen(dsp->wmfw_file_name));
-
-       mutex_unlock(&dsp->pwr_lock);
-       return ret;
+       return cs_dsp_debugfs_string_read(dsp, user_buf, count, ppos,
+                                         &dsp->wmfw_file_name);
 }
 
 static ssize_t cs_dsp_debugfs_bin_read(struct file *file,
@@ -435,19 +442,9 @@ static ssize_t cs_dsp_debugfs_bin_read(struct file *file,
                                       size_t count, loff_t *ppos)
 {
        struct cs_dsp *dsp = file->private_data;
-       ssize_t ret;
-
-       mutex_lock(&dsp->pwr_lock);
 
-       if (!dsp->bin_file_name || !dsp->booted)
-               ret = 0;
-       else
-               ret = simple_read_from_buffer(user_buf, count, ppos,
-                                             dsp->bin_file_name,
-                                             strlen(dsp->bin_file_name));
-
-       mutex_unlock(&dsp->pwr_lock);
-       return ret;
+       return cs_dsp_debugfs_string_read(dsp, user_buf, count, ppos,
+                                         &dsp->bin_file_name);
 }
 
 static const struct {

diff --git a/include/linux/firmware/cirrus/cs_dsp.h b/include/linux/firmware/cirrus/cs_dsp.h
index a66eb7624730c43e116ceaaba0bf18f011aec3e1..69959032f8f51e375e87471720d10232b824d187 100644 (file)
--- a/include/linux/firmware/cirrus/cs_dsp.h
+++ b/include/linux/firmware/cirrus/cs_dsp.h
@@ -188,8 +188,8 @@ struct cs_dsp {
 
 #ifdef CONFIG_DEBUG_FS
        struct dentry *debugfs_root;
-       char *wmfw_file_name;
-       char *bin_file_name;
+       const char *wmfw_file_name;
+       const char *bin_file_name;
 #endif
 };