ath9k: add external_reset callback to ath9k_platfom_data for AR9330

The patch adds a callback to ath9k_platform_data. If the
callback is provided by the platform code, then it can be
used to hard reset the WMAC device.

The callback is required for doing a hard reset of the AR9330
chips to get them working again after a hang.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 38 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index 4da5284c7773..839ba64c9e49 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1161,6 +1161,41 @@ static bool ath9k_hw_set_reset(struct ath_hw *ah, int type)
                         rst_flags |= AR_RTC_RC_MAC_COLD;
         }
 
+        if (AR_SREV_9330(ah)) {
+                int npend = 0;
+                int i;
+
+                /* AR9330 WAR:
+                 * call external reset function to reset WMAC if:
+                 * - doing a cold reset
+                 * - we have pending frames in the TX queues
+                 */
+
+                for (i = 0; i < AR_NUM_QCU; i++) {
+                        npend = ath9k_hw_numtxpending(ah, i);
+                        if (npend)
+                                break;
+                }
+
+                if (ah->external_reset &&
+                    (npend || type == ATH9K_RESET_COLD)) {
+                        int reset_err = 0;
+
+                        ath_dbg(ath9k_hw_common(ah), ATH_DBG_RESET,
+                                "reset MAC via external reset\n");
+
+                        reset_err = ah->external_reset();
+                        if (reset_err) {
+                                ath_err(ath9k_hw_common(ah),
+                                        "External reset failed, err=%d\n",
+                                        reset_err);
+                                return false;
+                        }
+
+                        REG_WRITE(ah, AR_RTC_RESET, 1);
+                }
+        }
+
         REG_WRITE(ah, AR_RTC_RC, rst_flags);
 
         REGWRITE_BUFFER_FLUSH(ah);
diff --git a/drivers/net/wireless/ath/ath9k/hw.h b/drivers/net/wireless/ath/ath9k/hw.h
index 0749fa8c3a58..818acdd1ba90 100644
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -863,6 +863,7 @@ struct ath_hw {
 
         bool is_clk_25mhz;
         int (*get_mac_revision)(void);
+        int (*external_reset)(void);
 };
 
 struct ath_bus_ops {
diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c
index 1851c222fff0..50103b2792b5 100644
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -575,6 +575,7 @@ static int ath9k_init_softc(u16 devid, struct ath_softc *sc, u16 subsysid,
                 sc->sc_ah->led_pin = pdata->led_pin;
                 ah->is_clk_25mhz = pdata->is_clk_25mhz;
                 ah->get_mac_revision = pdata->get_mac_revision;
+                ah->external_reset = pdata->external_reset;
         }
 
         common = ath9k_hw_common(ah);
diff --git a/include/linux/ath9k_platform.h b/include/linux/ath9k_platform.h
index c207607acada..6e3f54f37844 100644
--- a/include/linux/ath9k_platform.h
+++ b/include/linux/ath9k_platform.h
@@ -31,6 +31,7 @@ struct ath9k_platform_data {
 
         bool is_clk_25mhz;
         int (*get_mac_revision)(void);
+        int (*external_reset)(void);
 };
 
 #endif /* _LINUX_ATH9K_PLATFORM_H */