ASoC: fsl-ssi: Move sysfs stats to debugfs

Interrupt statistics of fsl_ssi are mainly for debugging purpose. Most
of those interrupts show error states, e.g. under/overflow.
The stats should be exposed via debugfs instead of sysfs.

This patch moves the statistics file to debugfs.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 117 insertions, 67 deletions

diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c
index 19891f2a5de4..e483e9d84f8b 100644
--- a/sound/soc/fsl/fsl_ssi.c
+++ b/sound/soc/fsl/fsl_ssi.c
@@ -35,6 +35,7 @@
 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/clk.h>
+#include <linux/debugfs.h>
 #include <linux/device.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
@@ -114,6 +115,14 @@ static inline void write_ssi_mask(u32 __iomem *addr, u32 clear, u32 set)
                     CCSR_SSI_SIER_RDMAE | CCSR_SSI_SIER_RIE | \
                     CCSR_SSI_SIER_ROE0_EN | CCSR_SSI_SIER_ROE1_EN)
 
+#define FSLSSI_SIER_DBG_RX_FLAGS (CCSR_SSI_SIER_RFF0_EN | \
+                CCSR_SSI_SIER_RLS_EN | CCSR_SSI_SIER_RFS_EN | \
+                CCSR_SSI_SIER_ROE0_EN | CCSR_SSI_SIER_RFRC_EN)
+#define FSLSSI_SIER_DBG_TX_FLAGS (CCSR_SSI_SIER_TFE0_EN | \
+                CCSR_SSI_SIER_TLS_EN | CCSR_SSI_SIER_TFS_EN | \
+                CCSR_SSI_SIER_TUE0_EN | CCSR_SSI_SIER_TFRC_EN)
+#define FSLSSI_SISR_MASK (FSLSSI_SIER_DBG_RX_FLAGS | FSLSSI_SIER_DBG_TX_FLAGS)
+
 /**
  * fsl_ssi_private: per-SSI private data
  *
@@ -133,7 +142,6 @@ struct fsl_ssi_private {
         unsigned int irq;
         unsigned int fifo_depth;
         struct snd_soc_dai_driver cpu_dai_drv;
-        struct device_attribute dev_attr;
         struct platform_device *pdev;
 
         bool new_binding;
@@ -175,6 +183,8 @@ struct fsl_ssi_private {
                 unsigned int tfe1;
                 unsigned int tfe0;
         } stats;
+        struct dentry *dbg_dir;
+        struct dentry *dbg_stats;
 
         char name[1];
 };
@@ -203,7 +213,7 @@ static irqreturn_t fsl_ssi_isr(int irq, void *dev_id)
            were interrupted for.  We mask it with the Interrupt Enable register
            so that we only check for events that we're interested in.
          */
-        sisr = read_ssi(&ssi->sisr) & SIER_FLAGS;
+        sisr = read_ssi(&ssi->sisr) & FSLSSI_SISR_MASK;
 
         if (sisr & CCSR_SSI_SISR_RFRC) {
                 ssi_private->stats.rfrc++;
@@ -323,6 +333,102 @@ static irqreturn_t fsl_ssi_isr(int irq, void *dev_id)
         return ret;
 }
 
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+/* Show the statistics of a flag only if its interrupt is enabled.  The
+ * compiler will optimze this code to a no-op if the interrupt is not
+ * enabled.
+ */
+#define SIER_SHOW(flag, name) \
+        do { \
+                if (FSLSSI_SISR_MASK & CCSR_SSI_SIER_##flag) \
+                        seq_printf(s, #name "=%u\n", ssi_private->stats.name); \
+        } while (0)
+
+
+/**
+ * fsl_sysfs_ssi_show: display SSI statistics
+ *
+ * Display the statistics for the current SSI device.  To avoid confusion,
+ * we only show those counts that are enabled.
+ */
+static ssize_t fsl_ssi_stats_show(struct seq_file *s, void *unused)
+{
+        struct fsl_ssi_private *ssi_private = s->private;
+
+        SIER_SHOW(RFRC_EN, rfrc);
+        SIER_SHOW(TFRC_EN, tfrc);
+        SIER_SHOW(CMDAU_EN, cmdau);
+        SIER_SHOW(CMDDU_EN, cmddu);
+        SIER_SHOW(RXT_EN, rxt);
+        SIER_SHOW(RDR1_EN, rdr1);
+        SIER_SHOW(RDR0_EN, rdr0);
+        SIER_SHOW(TDE1_EN, tde1);
+        SIER_SHOW(TDE0_EN, tde0);
+        SIER_SHOW(ROE1_EN, roe1);
+        SIER_SHOW(ROE0_EN, roe0);
+        SIER_SHOW(TUE1_EN, tue1);
+        SIER_SHOW(TUE0_EN, tue0);
+        SIER_SHOW(TFS_EN, tfs);
+        SIER_SHOW(RFS_EN, rfs);
+        SIER_SHOW(TLS_EN, tls);
+        SIER_SHOW(RLS_EN, rls);
+        SIER_SHOW(RFF1_EN, rff1);
+        SIER_SHOW(RFF0_EN, rff0);
+        SIER_SHOW(TFE1_EN, tfe1);
+        SIER_SHOW(TFE0_EN, tfe0);
+
+        return 0;
+}
+
+static int fsl_ssi_stats_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, fsl_ssi_stats_show, inode->i_private);
+}
+
+static const struct file_operations fsl_ssi_stats_ops = {
+        .open = fsl_ssi_stats_open,
+        .read = seq_read,
+        .llseek = seq_lseek,
+        .release = single_release,
+};
+
+static int fsl_ssi_debugfs_create(struct fsl_ssi_private *ssi_private,
+                struct device *dev)
+{
+        ssi_private->dbg_dir = debugfs_create_dir(dev_name(dev), NULL);
+        if (!ssi_private->dbg_dir)
+                return -ENOMEM;
+
+        ssi_private->dbg_stats = debugfs_create_file("stats", S_IRUGO,
+                        ssi_private->dbg_dir, ssi_private, &fsl_ssi_stats_ops);
+        if (!ssi_private->dbg_stats) {
+                debugfs_remove(ssi_private->dbg_dir);
+                return -ENOMEM;
+        }
+
+        return 0;
+}
+
+static void fsl_ssi_debugfs_remove(struct fsl_ssi_private *ssi_private)
+{
+        debugfs_remove(ssi_private->dbg_stats);
+        debugfs_remove(ssi_private->dbg_dir);
+}
+
+#else
+
+static int fsl_ssi_debugfs_create(struct fsl_ssi_private *ssi_private,
+                struct device *dev)
+{
+        return 0;
+}
+
+static void fsl_ssi_debugfs_remove(struct fsl_ssi_private *ssi_private)
+{
+}
+
+#endif /* IS_ENABLED(CONFIG_DEBUG_FS) */
+
 static void fsl_ssi_setup_ac97(struct fsl_ssi_private *ssi_private)
 {
         struct ccsr_ssi __iomem *ssi = ssi_private->ssi;
@@ -991,56 +1097,6 @@ static struct snd_ac97_bus_ops fsl_ssi_ac97_ops = {
         .write          = fsl_ssi_ac97_write,
 };
 
-/* Show the statistics of a flag only if its interrupt is enabled.  The
- * compiler will optimze this code to a no-op if the interrupt is not
- * enabled.
- */
-#define SIER_SHOW(flag, name) \
-        do { \
-                if (SIER_FLAGS & CCSR_SSI_SIER_##flag) \
-                        length += sprintf(buf + length, #name "=%u\n", \
-                                ssi_private->stats.name); \
-        } while (0)
-
-
-/**
- * fsl_sysfs_ssi_show: display SSI statistics
- *
- * Display the statistics for the current SSI device.  To avoid confusion,
- * we only show those counts that are enabled.
- */
-static ssize_t fsl_sysfs_ssi_show(struct device *dev,
-        struct device_attribute *attr, char *buf)
-{
-        struct fsl_ssi_private *ssi_private =
-                container_of(attr, struct fsl_ssi_private, dev_attr);
-        ssize_t length = 0;
-
-        SIER_SHOW(RFRC_EN, rfrc);
-        SIER_SHOW(TFRC_EN, tfrc);
-        SIER_SHOW(CMDAU_EN, cmdau);
-        SIER_SHOW(CMDDU_EN, cmddu);
-        SIER_SHOW(RXT_EN, rxt);
-        SIER_SHOW(RDR1_EN, rdr1);
-        SIER_SHOW(RDR0_EN, rdr0);
-        SIER_SHOW(TDE1_EN, tde1);
-        SIER_SHOW(TDE0_EN, tde0);
-        SIER_SHOW(ROE1_EN, roe1);
-        SIER_SHOW(ROE0_EN, roe0);
-        SIER_SHOW(TUE1_EN, tue1);
-        SIER_SHOW(TUE0_EN, tue0);
-        SIER_SHOW(TFS_EN, tfs);
-        SIER_SHOW(RFS_EN, rfs);
-        SIER_SHOW(TLS_EN, tls);
-        SIER_SHOW(RLS_EN, rls);
-        SIER_SHOW(RFF1_EN, rff1);
-        SIER_SHOW(RFF0_EN, rff0);
-        SIER_SHOW(TFE1_EN, tfe1);
-        SIER_SHOW(TFE0_EN, tfe0);
-
-        return length;
-}
-
 /**
  * Make every character in a string lower-case
  */
@@ -1233,20 +1289,6 @@ static int fsl_ssi_probe(struct platform_device *pdev)
                 }
         }
 
-        /* Initialize the the device_attribute structure */
-        dev_attr = &ssi_private->dev_attr;
-        sysfs_attr_init(&dev_attr->attr);
-        dev_attr->attr.name = "statistics";
-        dev_attr->attr.mode = S_IRUGO;
-        dev_attr->show = fsl_sysfs_ssi_show;
-
-        ret = device_create_file(&pdev->dev, dev_attr);
-        if (ret) {
-                dev_err(&pdev->dev, "could not create sysfs %s file\n",
-                        ssi_private->dev_attr.attr.name);
-                goto error_clk;
-        }
-
         /* Register with ASoC */
         dev_set_drvdata(&pdev->dev, ssi_private);
 
@@ -1257,6 +1299,10 @@ static int fsl_ssi_probe(struct platform_device *pdev)
                 goto error_dev;
         }
 
+        ret = fsl_ssi_debugfs_create(ssi_private, &pdev->dev);
+        if (ret)
+                goto error_dbgfs;
+
         if (ssi_private->ssi_on_imx) {
                 if (!ssi_private->use_dma) {
 
@@ -1326,6 +1372,9 @@ error_dai:
                 imx_pcm_fiq_exit(pdev);
 
 error_pcm:
+        fsl_ssi_debugfs_remove(ssi_private);
+
+error_dbgfs:
         snd_soc_unregister_component(&pdev->dev);
 
 error_dev:
@@ -1349,10 +1398,11 @@ static int fsl_ssi_remove(struct platform_device *pdev)
 {
         struct fsl_ssi_private *ssi_private = dev_get_drvdata(&pdev->dev);
 
+        fsl_ssi_debugfs_remove(ssi_private);
+
         if (!ssi_private->new_binding)
                 platform_device_unregister(ssi_private->pdev);
         snd_soc_unregister_component(&pdev->dev);
-        device_remove_file(&pdev->dev, &ssi_private->dev_attr);
         if (ssi_private->ssi_on_imx) {
                 if (!IS_ERR(ssi_private->baudclk))
                         clk_disable_unprepare(ssi_private->baudclk);