From eb3a97a69be83ea961bf4a164c54e1c989a57850 Mon Sep 17 00:00:00 2001 From: Christian Lamparter Date: Mon, 13 Sep 2021 15:40:35 +0300 Subject: [PATCH] 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 Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/f9b732b50a3453fadf3923cc75d365bae3505fe7.1630157099.git.chunkeey@gmail.com --- 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 c22d457..e6b3cd4 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 b7b65b1..096a206 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 e9a36dd..1568730 100644 --- a/drivers/net/wireless/ath/ath9k/init.c +++ b/drivers/net/wireless/ath/ath9k/init.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include #include @@ -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; -- 2.7.4