ath9k: Read and write the TSF via debugfs

This patch adds an ath9k specific entry to read, write and reset the TSF into the debugfs, like in ath5k. This makes debugging the IBSS handling of wifi drivers _much_ easier.

Signed-off-by: Alina Friedrichsen <x-alina@gmx.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath9k/ath9k.h

@@ -899,6 +899,7 @@ void ath9k_hw_getbssidmask(struct ath_hal *ah, u8 *mask);
 bool ath9k_hw_setbssidmask(struct ath_hal *ah, const u8 *mask);
 void ath9k_hw_write_associd(struct ath_hal *ah, const u8 *bssid, u16 assocId);
 u64 ath9k_hw_gettsf64(struct ath_hal *ah);
+void ath9k_hw_settsf64(struct ath_hal *ah, u64 tsf64);
 void ath9k_hw_reset_tsf(struct ath_hal *ah);
 bool ath9k_hw_set_tsfadjust(struct ath_hal *ah, u32 setting);
 bool ath9k_hw_setslottime(struct ath_hal *ah, u32 us);

drivers/net/wireless/ath9k/core.h

@@ -141,6 +141,7 @@ struct ath9k_debug {
 	struct dentry *debugfs_phy;
 	struct dentry *debugfs_dma;
 	struct dentry *debugfs_interrupt;
+	struct dentry *debugfs_tsf;
 	struct ath_stats stats;
 };
 

drivers/net/wireless/ath9k/debug.c

@@ -222,6 +222,49 @@ static const struct file_operations fops_interrupt = {
 	.owner = THIS_MODULE
 };
 
+
+static ssize_t read_file_tsf(struct file *file, char __user *user_buf,
+			     size_t count, loff_t *ppos)
+{
+	struct ath_softc *sc = file->private_data;
+	char buf[100];
+	snprintf(buf, sizeof(buf), "0x%016llx\n",
+		 (unsigned long long)ath9k_hw_gettsf64(sc->sc_ah));
+	return simple_read_from_buffer(user_buf, count, ppos, buf, 19);
+}
+
+static ssize_t write_file_tsf(struct file *file,
+                              const char __user *user_buf,
+                              size_t count, loff_t *ppos)
+{
+	struct ath_softc *sc = file->private_data;
+	char buf[21];
+	unsigned long long tsf;
+
+	if (copy_from_user(buf, user_buf, min(count, sizeof(buf) - 1)))
+		return -EFAULT;
+	buf[sizeof(buf) - 1] = '\0';
+
+	if (strncmp(buf, "reset", 5) == 0) {
+		ath9k_hw_reset_tsf(sc->sc_ah);
+		printk(KERN_INFO "debugfs reset TSF\n");
+	} else {
+		tsf = simple_strtoul(buf, NULL, 0);
+		ath9k_hw_settsf64(sc->sc_ah, tsf);
+		printk(KERN_INFO "debugfs set TSF to %#018llx\n", tsf);
+	}
+
+	return count;
+}
+
+static const struct file_operations fops_tsf = {
+	.read = read_file_tsf,
+	.write = write_file_tsf,
+	.open = ath9k_debugfs_open,
+	.owner = THIS_MODULE
+};
+
+
 int ath9k_init_debug(struct ath_softc *sc)
 {
 	sc->sc_debug.debug_mask = ath9k_debug;
@@ -247,6 +290,11 @@ int ath9k_init_debug(struct ath_softc *sc)
 	if (!sc->sc_debug.debugfs_interrupt)
 		goto err;
 
+	sc->sc_debug.debugfs_tsf = debugfs_create_file("tsf", S_IRUGO,
+				       sc->sc_debug.debugfs_phy, sc, &fops_tsf);
+	if (!sc->sc_debug.debugfs_tsf)
+		goto err;
+
 	return 0;
 err:
 	ath9k_exit_debug(sc);
@@ -255,6 +303,7 @@ err:
 
 void ath9k_exit_debug(struct ath_softc *sc)
 {
+	debugfs_remove(sc->sc_debug.debugfs_tsf);
 	debugfs_remove(sc->sc_debug.debugfs_interrupt);
 	debugfs_remove(sc->sc_debug.debugfs_dma);
 	debugfs_remove(sc->sc_debug.debugfs_phy);

drivers/net/wireless/ath9k/hw.c

@@ -3755,6 +3755,13 @@ u64 ath9k_hw_gettsf64(struct ath_hal *ah)
 	return tsf;
 }
 
+void ath9k_hw_settsf64(struct ath_hal *ah, u64 tsf64)
+{
+	REG_WRITE(ah, AR_TSF_L32, 0x00000000);
+	REG_WRITE(ah, AR_TSF_U32, (tsf64 >> 32) & 0xffffffff);
+	REG_WRITE(ah, AR_TSF_L32, tsf64 & 0xffffffff);
+}
+
 void ath9k_hw_reset_tsf(struct ath_hal *ah)
 {
 	int count;