Commit eb3a97a6 authored by Christian Lamparter's avatar Christian Lamparter Committed by Kalle Valo
Browse files

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 4b361cfa ("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: default avatarChristian Lamparter <chunkeey@gmail.com>
Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/f9b732b50a3453fadf3923cc75d365bae3505fe7.1630157099.git.chunkeey@gmail.com
parent 6880fa6c

drivers/net/wireless/ath/ath9k/eeprom.c

+11 −1
Original line number Diff line number Diff line
@@ -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);

drivers/net/wireless/ath/ath9k/hw.h

+2 −0
Original line number Diff line number Diff line
@@ -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;

drivers/net/wireless/ath/ath9k/init.c

+56 −0
Original line number Diff line number Diff line
@@ -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;