mvl8787: add debugfs for reading from scratch register

drivers/net/wireless/mwl8787/Makefile

@@ -1,4 +1,4 @@
-mwl8787_sdio-objs := main.o tx.o rx.o cmd.o sdio.o scan.o event.o
+mwl8787_sdio-objs := main.o tx.o rx.o cmd.o sdio.o scan.o event.o debugfs.o
 mwl8787_sdio-$(CONFIG_NL80211_TESTMODE) += testmode.o
 
 obj-$(CONFIG_MWL8787) += mwl8787_sdio.o

drivers/net/wireless/mwl8787/debugfs.c

@@ -0,0 +1,69 @@
+#include <linux/debugfs.h>
+#include "mwl8787.h"
+#include "sdio.h"
+
+static ssize_t
+mwl8787_scratch_read(struct file *file, char __user *ubuf,
+		     size_t count, loff_t *ppos)
+{
+	struct mwl8787_priv *priv =
+		(struct mwl8787_priv *) file->private_data;
+
+	char buf[17] = {};
+	int pos = 0, ret = 0;
+	u64 reg_value;
+
+	/* read scratch reg */
+	ret = mwl8787_read_scratch_area(priv, &reg_value);
+
+	if (ret) {
+		ret = -EINVAL;
+		goto done;
+	}
+
+	pos += snprintf(buf, sizeof(buf), "%016llx\n", reg_value);
+
+	ret = simple_read_from_buffer(ubuf, count, ppos, buf, pos);
+done:
+	return ret;
+}
+
+#define MWL8787_DFS_ADD_FILE(name) \
+	debugfs_create_file(#name, 0644, priv->dfs_dev_dir,		\
+			priv, &mwl8787_dfs_##name##_fops);		\
+
+
+#define MWL8787_DFS_FILE_READ_OPS(name)                                 \
+static const struct file_operations mwl8787_dfs_##name##_fops = {       \
+	.read = mwl8787_##name##_read,                                  \
+	.open = simple_open,                                            \
+};
+
+MWL8787_DFS_FILE_READ_OPS(scratch);
+
+/*
+ * This function creates the debugfs directory and files.
+ */
+void
+mwl8787_dev_debugfs_init(struct mwl8787_priv *priv)
+{
+	if (!priv)
+		return;
+
+	priv->dfs_dev_dir = debugfs_create_dir("mwl8787",
+		priv->hw->wiphy->debugfsdir);
+
+	MWL8787_DFS_ADD_FILE(scratch);
+}
+
+/*
+ * This function removes the debugfs directory and files
+ */
+void
+mwl8787_dev_debugfs_remove(struct mwl8787_priv *priv)
+{
+	if (!priv)
+		return;
+
+	debugfs_remove_recursive(priv->dfs_dev_dir);
+}

drivers/net/wireless/mwl8787/main.c

@@ -4,6 +4,7 @@
 
 #include "mwl8787.h"
 #include "fw.h"
+#include "sdio.h"
 
 #define CREATE_TRACE_POINTS
 #include "trace.h"

drivers/net/wireless/mwl8787/mwl8787.h

@@ -67,6 +67,7 @@ struct mwl8787_priv
 	struct sk_buff_head tx_queue;
 
 	struct ieee80211_channel *channel;
+	struct dentry *dfs_dev_dir;
 
 	/* sdio */
 	u32 ioport;

drivers/net/wireless/mwl8787/sdio.c

@@ -135,6 +135,23 @@ mwl8787_sdio_poll_card_status(struct mwl8787_priv *priv, u8 bits)
 	return -1;
 }
 
+/*
+ * This function reads the scratch area used by firmware to report error codes.
+ */
+int mwl8787_read_scratch_area(struct mwl8787_priv *priv, u64 *dat)
+{
+	u32 i;
+	u8 scrch;
+
+	for (i = 0; i < MWL8787_REG_SCRATCH_LEN; i++) {
+		if (mwl8787_read_reg(priv, MWL8787_REG_SCRATCH_START + i, &scrch))
+			return -1;
+		*dat = ((*dat << 8) | scrch);
+	}
+
+	return 0;
+}
+
 /*
  * This function reads the firmware status.
  */
@@ -930,6 +947,9 @@ static void mwl8787_fw_cb(const struct firmware *fw, void *context)
 
 	/* FW loaded, so register with mac80211 */
 	ret = mwl8787_register(priv);
+
+	/* create debugfs */
+	mwl8787_dev_debugfs_init(priv);
 	if (ret)
 		goto disable;
 
@@ -1012,6 +1032,7 @@ static void mwl8787_sdio_remove(struct sdio_func *func)
 	sdio_release_host(func);
 
 	kfree(priv->mp_regs);
+	mwl8787_dev_debugfs_remove(priv);
 	mwl8787_free(priv);
 }
 

drivers/net/wireless/mwl8787/sdio.h

@@ -116,10 +116,15 @@
 #define MWL8787_REG_POLL		0x30
 #define MWL8787_REG_STATUS_0		0x60
 #define MWL8787_REG_STATUS_1		0x61
+#define MWL8787_REG_SCRATCH_START	0x62
+#define MWL8787_REG_SCRATCH_LEN		0x8
 #define MWL8787_REG_CARD_MISC_CFG	0x6c
 
 #define MWL8787_SDIO_BLOCK_SIZE            256
 
+int mwl8787_read_scratch_area(struct mwl8787_priv *priv, u64 *dat);
+void mwl8787_dev_debugfs_init(struct mwl8787_priv *priv);
+void mwl8787_dev_debugfs_remove(struct mwl8787_priv *priv);
 
 enum mwl8787_sdio_type {
 	MWL8787_TYPE_DATA = 0,