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author | Christian Lamparter <chunkeey@gmail.com> | 2021-09-13 15:40:35 +0300 |
---|---|---|
committer | Kalle Valo <kvalo@codeaurora.org> | 2021-09-16 11:07:41 +0300 |
commit | eb3a97a69be83ea961bf4a164c54e1c989a57850 (patch) | |
tree | 131094e75bd6c6091a312ff1754c2bfd2945a681 /drivers/net/wireless/ath/ath9k/init.c | |
parent | 6880fa6c56601bb8ed59df6c30fd390cc5f6dd8f (diff) | |
download | linux-next-eb3a97a69be83ea961bf4a164c54e1c989a57850.tar.gz |
ath9k: fetch calibration data via nvmem subsystem
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 either
in the platform data or via device-tree allows drivers to get
the data necessary for initializing the WIFI, without having
to wait around for the filesystem and userspace to do
the extractions.
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/f9b732b50a3453fadf3923cc75d365bae3505fe7.1630157099.git.chunkeey@gmail.com
Diffstat (limited to 'drivers/net/wireless/ath/ath9k/init.c')
-rw-r--r-- | drivers/net/wireless/ath/ath9k/init.c | 56 |
1 files changed, 56 insertions, 0 deletions
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; |