ath9k: allow to load EEPROM content via firmware API

The calibration data for devices w/o a separate
EEPROM chip can be specified via the 'eeprom_data'
field of 'ath9k_platform_data'. The 'eeprom_data'
is usually filled from board specific setup
functions. It is easy if the EEPROM data is mapped
to the memory, but it can be complicated if it is
stored elsewhere.

The patch adds support for loading of the EEPROM
data via the firmware API to avoid this limitation.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c
index 80cae53..27703a5 100644
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -23,6 +23,11 @@
 
 #include "ath9k.h"
 
+struct ath9k_eeprom_ctx {
+	struct completion complete;
+	struct ath_hw *ah;
+};
+
 static char *dev_info = "ath9k";
 
 MODULE_AUTHOR("Atheros Communications");
@@ -506,6 +511,51 @@
 		sc->ant_comb.count = ATH_ANT_DIV_COMB_INIT_COUNT;
 }
 
+static void ath9k_eeprom_request_cb(const struct firmware *eeprom_blob,
+				    void *ctx)
+{
+	struct ath9k_eeprom_ctx *ec = ctx;
+
+	if (eeprom_blob)
+		ec->ah->eeprom_blob = eeprom_blob;
+
+	complete(&ec->complete);
+}
+
+static int ath9k_eeprom_request(struct ath_softc *sc, const char *name)
+{
+	struct ath9k_eeprom_ctx ec;
+	struct ath_hw *ah = ah = sc->sc_ah;
+	int err;
+
+	/* try to load the EEPROM content asynchronously */
+	init_completion(&ec.complete);
+	ec.ah = sc->sc_ah;
+
+	err = request_firmware_nowait(THIS_MODULE, 1, name, sc->dev, GFP_KERNEL,
+				      &ec, ath9k_eeprom_request_cb);
+	if (err < 0) {
+		ath_err(ath9k_hw_common(ah),
+			"EEPROM request failed\n");
+		return err;
+	}
+
+	wait_for_completion(&ec.complete);
+
+	if (!ah->eeprom_blob) {
+		ath_err(ath9k_hw_common(ah),
+			"Unable to load EEPROM file %s\n", name);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void ath9k_eeprom_release(struct ath_softc *sc)
+{
+	release_firmware(sc->sc_ah->eeprom_blob);
+}
+
 static int ath9k_init_softc(u16 devid, struct ath_softc *sc,
 			    const struct ath_bus_ops *bus_ops)
 {
@@ -583,6 +633,12 @@
 	ath_read_cachesize(common, &csz);
 	common->cachelsz = csz << 2; /* convert to bytes */
 
+	if (pdata->eeprom_name) {
+		ret = ath9k_eeprom_request(sc, pdata->eeprom_name);
+		if (ret)
+			goto err_eeprom;
+	}
+
 	/* Initializes the hardware for all supported chipsets */
 	ret = ath9k_hw_init(ah);
 	if (ret)
@@ -619,7 +675,8 @@
 err_queues:
 	ath9k_hw_deinit(ah);
 err_hw:
-
+	ath9k_eeprom_release(sc);
+err_eeprom:
 	kfree(ah);
 	sc->sc_ah = NULL;
 
@@ -882,6 +939,7 @@
 	if (sc->dfs_detector != NULL)
 		sc->dfs_detector->exit(sc->dfs_detector);
 
+	ath9k_eeprom_release(sc);
 	kfree(sc->sc_ah);
 	sc->sc_ah = NULL;
 }