diff mbox series

[v1,1/2] ath9k: fetch calibration data via nvmem subsystem

Message ID f9b732b50a3453fadf3923cc75d365bae3505fe7.1630157099.git.chunkeey@gmail.com
State New
Headers show
Series [v1,1/2] ath9k: fetch calibration data via nvmem subsystem | expand

Commit Message

Christian Lamparter Aug. 28, 2021, 1:27 p.m. UTC
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>
---
 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(-)

Comments

Kalle Valo Sept. 16, 2021, 8:08 a.m. UTC | #1
Christian Lamparter <chunkeey@gmail.com> wrote:

> 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>


2 patches applied to ath-next branch of ath.git, thanks.

eb3a97a69be8 ath9k: fetch calibration data via nvmem subsystem
ef7bc2a76342 ath9k: owl-loader: fetch pci init values through nvmem

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/f9b732b50a3453fadf3923cc75d365bae3505fe7.1630157099.git.chunkeey@gmail.com/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
diff mbox series

Patch

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;