at86rf230: add debugfs support

This patch introduce debugfs support for collect trac status stats. To
clear the stats ifdown the interface of at86rf230 and start the
interface again.

Signed-off-by: Alexander Aring <[e-mail]>
Reviewed-by: Stefan Schmidt <[e-mail]>
Signed-off-by: Marcel Holtmann <[e-mail]>

drivers/net/ieee802154/Kconfig

···
 	  This driver can also be built as a module. To do so, say M here.
 	  the module will be called 'at86rf230'.
 
+config IEEE802154_AT86RF230_DEBUGFS
+	depends on IEEE802154_AT86RF230
+	bool "AT86RF230 debugfs interface"
+	depends on DEBUG_FS
+	---help---
+	  This option compiles debugfs code for the at86rf230 driver.
+
 config IEEE802154_MRF24J40
 	tristate "Microchip MRF24J40 transceiver driver"
 	depends on IEEE802154_DRIVERS && MAC802154

drivers/net/ieee802154/at86rf230.c

···
 #include <linux/skbuff.h>
 #include <linux/of_gpio.h>
 #include <linux/ieee802154.h>
+#include <linux/debugfs.h>
 
 #include <net/mac802154.h>
 #include <net/cfg802154.h>
···
 	bool irq_enable;
 };
 
+struct at86rf230_trac {
+	u64 success;
+	u64 success_data_pending;
+	u64 success_wait_for_ack;
+	u64 channel_access_failure;
+	u64 no_ack;
+	u64 invalid;
+};
+
 struct at86rf230_local {
 	struct spi_device *spi;
 
···
 	u8 tx_retry;
 	struct sk_buff *tx_skb;
 	struct at86rf230_state_change tx;
+
+	struct at86rf230_trac trac;
 };
 
 #define AT86RF2XX_NUMREGS 0x3F
···
 	struct at86rf230_state_change *ctx = context;
 	struct at86rf230_local *lp = ctx->lp;
 
+	if (IS_ENABLED(CONFIG_IEEE802154_AT86RF230_DEBUGFS)) {
+		u8 trac = TRAC_MASK(ctx->buf[1]);
+
+		switch (trac) {
+		case TRAC_SUCCESS:
+			lp->trac.success++;
+			break;
+		case TRAC_SUCCESS_DATA_PENDING:
+			lp->trac.success_data_pending++;
+			break;
+		case TRAC_CHANNEL_ACCESS_FAILURE:
+			lp->trac.channel_access_failure++;
+			break;
+		case TRAC_NO_ACK:
+			lp->trac.no_ack++;
+			break;
+		case TRAC_INVALID:
+			lp->trac.invalid++;
+			break;
+		default:
+			WARN_ONCE(1, "received tx trac status %d\n", trac);
+			break;
+		}
+	}
+
 	at86rf230_async_state_change(lp, &lp->irq, STATE_TX_ON,
 				     at86rf230_tx_on, true);
 }
···
 }
 
 static void
-at86rf230_rx_read_frame(void *context)
+at86rf230_rx_trac_check(void *context)
 {
 	struct at86rf230_state_change *ctx = context;
 	struct at86rf230_local *lp = ctx->lp;
 	u8 *buf = ctx->buf;
 	int rc;
+
+	if (IS_ENABLED(CONFIG_IEEE802154_AT86RF230_DEBUGFS)) {
+		u8 trac = TRAC_MASK(buf[1]);
+
+		switch (trac) {
+		case TRAC_SUCCESS:
+			lp->trac.success++;
+			break;
+		case TRAC_SUCCESS_WAIT_FOR_ACK:
+			lp->trac.success_wait_for_ack++;
+			break;
+		case TRAC_INVALID:
+			lp->trac.invalid++;
+			break;
+		default:
+			WARN_ONCE(1, "received rx trac status %d\n", trac);
+			break;
+		}
+	}
 
 	buf[0] = CMD_FB;
 	ctx->trx.len = AT86RF2XX_MAX_BUF;
···
 		enable_irq(ctx->irq);
 		at86rf230_async_error(lp, ctx, rc);
 	}
-}
-
-static void
-at86rf230_rx_trac_check(void *context)
-{
-	/* Possible check on trac status here. This could be useful to make
-	 * some stats why receive is failed. Not used at the moment, but it's
-	 * maybe timing relevant. Datasheet doesn't say anything about this.
-	 * The programming guide say do it so.
-	 */
-
-	at86rf230_rx_read_frame(context);
 }
 
 static void
···
 at86rf230_start(struct ieee802154_hw *hw)
 {
 	struct at86rf230_local *lp = hw->priv;
+
+	/* reset trac stats on start */
+	if (IS_ENABLED(CONFIG_IEEE802154_AT86RF230_DEBUGFS))
+		memset(&lp->trac, 0, sizeof(struct at86rf230_trac));
 
 	at86rf230_awake(lp);
 	enable_irq(lp->spi->irq);
···
 	lp->tx.timer.function = at86rf230_async_state_timer;
 }
 
+#ifdef CONFIG_IEEE802154_AT86RF230_DEBUGFS
+static struct dentry *at86rf230_debugfs_root;
+
+static int at86rf230_stats_show(struct seq_file *file, void *offset)
+{
+	struct at86rf230_local *lp = file->private;
+	int ret;
+
+	ret = seq_printf(file, "SUCCESS:\t\t%8llu\n", lp->trac.success);
+	if (ret < 0)
+		return ret;
+
+	ret = seq_printf(file, "SUCCESS_DATA_PENDING:\t%8llu\n",
+			 lp->trac.success_data_pending);
+	if (ret < 0)
+		return ret;
+
+	ret = seq_printf(file, "SUCCESS_WAIT_FOR_ACK:\t%8llu\n",
+			 lp->trac.success_wait_for_ack);
+	if (ret < 0)
+		return ret;
+
+	ret = seq_printf(file, "CHANNEL_ACCESS_FAILURE:\t%8llu\n",
+			 lp->trac.channel_access_failure);
+	if (ret < 0)
+		return ret;
+
+	ret = seq_printf(file, "NO_ACK:\t\t\t%8llu\n", lp->trac.no_ack);
+	if (ret < 0)
+		return ret;
+
+	return seq_printf(file, "INVALID:\t\t%8llu\n", lp->trac.invalid);
+}
+
+static int at86rf230_stats_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, at86rf230_stats_show, inode->i_private);
+}
+
+static const struct file_operations at86rf230_stats_fops = {
+	.open		= at86rf230_stats_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int at86rf230_debugfs_init(struct at86rf230_local *lp)
+{
+	char debugfs_dir_name[DNAME_INLINE_LEN + 1] = "at86rf230-";
+	struct dentry *stats;
+
+	strncat(debugfs_dir_name, dev_name(&lp->spi->dev), DNAME_INLINE_LEN);
+
+	at86rf230_debugfs_root = debugfs_create_dir(debugfs_dir_name, NULL);
+	if (!at86rf230_debugfs_root)
+		return -ENOMEM;
+
+	stats = debugfs_create_file("trac_stats", S_IRUGO,
+				    at86rf230_debugfs_root, lp,
+				    &at86rf230_stats_fops);
+	if (!stats)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void at86rf230_debugfs_remove(void)
+{
+	debugfs_remove_recursive(at86rf230_debugfs_root);
+}
+#else
+static int at86rf230_debugfs_init(struct at86rf230_local *lp) { return 0; }
+static void at86rf230_debugfs_remove(void) { }
+#endif
+
 static int at86rf230_probe(struct spi_device *spi)
 {
 	struct ieee802154_hw *hw;
···
 	/* going into sleep by default */
 	at86rf230_sleep(lp);
 
-	rc = ieee802154_register_hw(lp->hw);
+	rc = at86rf230_debugfs_init(lp);
 	if (rc)
 		goto free_dev;
 
+	rc = ieee802154_register_hw(lp->hw);
+	if (rc)
+		goto free_debugfs;
+
 	return rc;
 
+free_debugfs:
+	at86rf230_debugfs_remove();
 free_dev:
 	ieee802154_free_hw(lp->hw);
 
···
 	at86rf230_write_subreg(lp, SR_IRQ_MASK, 0);
 	ieee802154_unregister_hw(lp->hw);
 	ieee802154_free_hw(lp->hw);
+	at86rf230_debugfs_remove();
 	dev_dbg(&spi->dev, "unregistered at86rf230\n");
 
 	return 0;

drivers/net/ieee802154/at86rf230.h

···
 #define STATE_TRANSITION_IN_PROGRESS 0x1F
 
 #define TRX_STATE_MASK		(0x1F)
+#define TRAC_MASK(x)		((x & 0xe0) >> 5)
+
+#define TRAC_SUCCESS			0
+#define TRAC_SUCCESS_DATA_PENDING	1
+#define TRAC_SUCCESS_WAIT_FOR_ACK	2
+#define TRAC_CHANNEL_ACCESS_FAILURE	3
+#define TRAC_NO_ACK			5
+#define TRAC_INVALID			7
 
 #endif /* !_AT86RF230_H */