iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

ath9k: fetch calibration data via nvmem subsystem

Browse Source 
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
This commit is contained in:
Christian Lamparter 2021-09-13 15:40:35 +03:00 committed by Kalle Valo
parent 6880fa6c56
commit eb3a97a69b
3 changed files with 69 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
drivers/net/wireless/ath/ath9k/eeprom.c
View File

@ -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);

2
drivers/net/wireless/ath/ath9k/hw.h
View File

@ -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;

56
drivers/net/wireless/ath/ath9k/init.c
View File

@ -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;