On most embedded ath9k devices (like range extenders,
routers, accesspoints, ...) the calibration data is
stored in a MTD partitions named "ART", or "caldata"/
"calibration".
Since commit 4b361cfa8624 ("mtd: core: add OTP nvmem provider support"):
All MTD partitions are all automatically available through
the nvmem subsystem. This feature - together with an nvmem cell definition
in the device-tree - allows drivers like ath9k to get the data necessary
for starting the WIFI, without having to wait around for the filesystem
and userspace to do the extractions.
Signed-off-by: Christian Lamparter <chunkeey@xxxxxxxxx>
---
drivers/net/wireless/ath/ath9k/eeprom.c | 12 +++++-
drivers/net/wireless/ath/ath9k/hw.h | 2 +
drivers/net/wireless/ath/ath9k/init.c | 56 +++++++++++++++++++++++++
3 files changed, 69 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wireless/ath/ath9k/eeprom.c b/drivers/net/wireless/ath/ath9k/eeprom.c
index c22d457dbc54..e6b3cd49ea18 100644
--- a/drivers/net/wireless/ath/ath9k/eeprom.c
+++ b/drivers/net/wireless/ath/ath9k/eeprom.c
@@ -135,13 +135,23 @@ static bool ath9k_hw_nvram_read_firmware(const struct firmware *eeprom_blob,
offset, data);
}
+static bool ath9k_hw_nvram_read_nvmem(struct ath_hw *ah, off_t offset,
+ u16 *data)
+{
+ return ath9k_hw_nvram_read_array(ah->nvmem_blob,
+ ah->nvmem_blob_len / sizeof(u16),
+ offset, data);
+}
+
bool ath9k_hw_nvram_read(struct ath_hw *ah, u32 off, u16 *data)
{
struct ath_common *common = ath9k_hw_common(ah);
struct ath9k_platform_data *pdata = ah->dev->platform_data;
bool ret;
- if (ah->eeprom_blob)
+ if (ah->nvmem_blob)
+ ret = ath9k_hw_nvram_read_nvmem(ah, off, data);
+ else if (ah->eeprom_blob)
ret = ath9k_hw_nvram_read_firmware(ah->eeprom_blob, off, data);
else if (pdata && !pdata->use_eeprom)
ret = ath9k_hw_nvram_read_pdata(pdata, off, data);
diff --git a/drivers/net/wireless/ath/ath9k/hw.h b/drivers/net/wireless/ath/ath9k/hw.h
index b7b65b1c90e8..096a206f49ed 100644
--- a/drivers/net/wireless/ath/ath9k/hw.h
+++ b/drivers/net/wireless/ath/ath9k/hw.h
@@ -977,6 +977,8 @@ struct ath_hw {
bool disable_5ghz;
const struct firmware *eeprom_blob;
+ u16 *nvmem_blob; /* devres managed */
+ size_t nvmem_blob_len;
struct ath_dynack dynack;
diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c
index e9a36dd7144f..1568730fc01e 100644
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -22,6 +22,7 @@
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_net.h>
+#include <linux/nvmem-consumer.h>
#include <linux/relay.h>
#include <linux/dmi.h>
#include <net/ieee80211_radiotap.h>
@@ -568,6 +569,57 @@ static void ath9k_eeprom_release(struct ath_softc *sc)
release_firmware(sc->sc_ah->eeprom_blob);
}
+static int ath9k_nvmem_request_eeprom(struct ath_softc *sc)
+{
+ struct ath_hw *ah = sc->sc_ah;
+ struct nvmem_cell *cell;
+ void *buf;
+ size_t len;
+ int err;
+
+ cell = devm_nvmem_cell_get(sc->dev, "calibration");
+ if (IS_ERR(cell)) {
+ err = PTR_ERR(cell);
+
+ /* nvmem cell might not be defined, or the nvmem
+ * subsystem isn't included. In this case, follow
+ * the established "just return 0;" convention of
+ * ath9k_init_platform to say:
+ * "All good. Nothing to see here. Please go on."
+ */
+ if (err == -ENOENT || err == -EOPNOTSUPP)
+ return 0;
+
+ return err;
+ }
+
+ buf = nvmem_cell_read(cell, &len);
+ if (IS_ERR(buf))
+ return PTR_ERR(buf);
+
+ /* run basic sanity checks on the returned nvram cell length.
+ * That length has to be a multiple of a "u16" (i.e.: & 1).
+ * Furthermore, it has to be more than "let's say" 512 bytes
+ * but less than the maximum of AR9300_EEPROM_SIZE (16kb).
+ */
+ if ((len & 1) == 1 || len < 512 || len >= AR9300_EEPROM_SIZE) {
+ kfree(buf);
+ return -EINVAL;
+ }
+
+ /* devres manages the calibration values release on shutdown */
+ ah->nvmem_blob = (u16 *)devm_kmemdup(sc->dev, buf, len, GFP_KERNEL);
+ kfree(buf);
+ if (IS_ERR(ah->nvmem_blob))
+ return PTR_ERR(ah->nvmem_blob);
+
+ ah->nvmem_blob_len = len;
+ ah->ah_flags &= ~AH_USE_EEPROM;
+ ah->ah_flags |= AH_NO_EEP_SWAP;
+
+ return 0;
+}
+
static int ath9k_init_platform(struct ath_softc *sc)
{
struct ath9k_platform_data *pdata = sc->dev->platform_data;
@@ -704,6 +756,10 @@ static int ath9k_init_softc(u16 devid, struct ath_softc *sc,
if (ret)
return ret;
+ ret = ath9k_nvmem_request_eeprom(sc);
+ if (ret)
+ return ret;
+
if (ath9k_led_active_high != -1)
ah->config.led_active_high = ath9k_led_active_high == 1;
--
2.33.0
