ath9k_hw: add support for reading EEPROM data from the internal OTP ROM

Some of the new AR9003 cards do not come with an external EEPROM chip
anymore. Calibration data on these cards is stored in the OTP ROM on
the chip.
This patch adds support for reading this data, and also adds support
for different EEPROM chip sizes (512 bytes instead of 1K).

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 84 insertions, 6 deletions

diff --git a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
index 1b4e99167b6c..230a1228de8e 100644
--- a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
+++ b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c
@@ -3104,6 +3104,36 @@ error:
 	return false;
 }
 
+static bool ar9300_otp_read_word(struct ath_hw *ah, int addr, u32 *data)
+{
+	REG_READ(ah, AR9300_OTP_BASE + (4 * addr));
+
+	if (!ath9k_hw_wait(ah, AR9300_OTP_STATUS, AR9300_OTP_STATUS_TYPE,
+			   AR9300_OTP_STATUS_VALID, 1000))
+		return false;
+
+	*data = REG_READ(ah, AR9300_OTP_READ_DATA);
+	return true;
+}
+
+static bool ar9300_read_otp(struct ath_hw *ah, int address, u8 *buffer,
+			    int count)
+{
+	u32 data;
+	int i;
+
+	for (i = 0; i < count; i++) {
+		int offset = 8 * ((address - i) % 4);
+		if (!ar9300_otp_read_word(ah, (address - i) / 4, &data))
+			return false;
+
+		buffer[i] = (data >> offset) & 0xff;
+	}
+
+	return true;
+}
+
+
 static void ar9300_comp_hdr_unpack(u8 *best, int *code, int *reference,
 				   int *length, int *major, int *minor)
 {
@@ -3221,6 +3251,26 @@ static int ar9300_compress_decision(struct ath_hw *ah,
 	return 0;
 }
 
+typedef bool (*eeprom_read_op)(struct ath_hw *ah, int address, u8 *buffer,
+			       int count);
+
+static bool ar9300_check_header(void *data)
+{
+	u32 *word = data;
+	return !(*word == 0 || *word == ~0);
+}
+
+static bool ar9300_check_eeprom_header(struct ath_hw *ah, eeprom_read_op read,
+				       int base_addr)
+{
+	u8 header[4];
+
+	if (!read(ah, base_addr, header, 4))
+		return false;
+
+	return ar9300_check_header(header);
+}
+
 /*
  * Read the configuration data from the eeprom.
  * The data can be put in any specified memory buffer.
@@ -3241,6 +3291,7 @@ static int ar9300_eeprom_restore_internal(struct ath_hw *ah,
 	int it;
 	u16 checksum, mchecksum;
 	struct ath_common *common = ath9k_hw_common(ah);
+	eeprom_read_op read;
 
 	word = kzalloc(2048, GFP_KERNEL);
 	if (!word)
@@ -3248,14 +3299,42 @@ static int ar9300_eeprom_restore_internal(struct ath_hw *ah,
 
 	memcpy(mptr, &ar9300_default, mdata_size);
 
+	read = ar9300_read_eeprom;
 	cptr = AR9300_BASE_ADDR;
+	ath_print(common, ATH_DBG_EEPROM,
+		"Trying EEPROM accesss at Address 0x%04x\n", cptr);
+	if (ar9300_check_eeprom_header(ah, read, cptr))
+		goto found;
+
+	cptr = AR9300_BASE_ADDR_512;
+	ath_print(common, ATH_DBG_EEPROM,
+		"Trying EEPROM accesss at Address 0x%04x\n", cptr);
+	if (ar9300_check_eeprom_header(ah, read, cptr))
+		goto found;
+
+	read = ar9300_read_otp;
+	cptr = AR9300_BASE_ADDR;
+	ath_print(common, ATH_DBG_EEPROM,
+		"Trying OTP accesss at Address 0x%04x\n", cptr);
+	if (ar9300_check_eeprom_header(ah, read, cptr))
+		goto found;
+
+	cptr = AR9300_BASE_ADDR_512;
+	ath_print(common, ATH_DBG_EEPROM,
+		"Trying OTP accesss at Address 0x%04x\n", cptr);
+	if (ar9300_check_eeprom_header(ah, read, cptr))
+		goto found;
+
+	goto fail;
+
+found:
+	ath_print(common, ATH_DBG_EEPROM, "Found valid EEPROM data");
+
 	for (it = 0; it < MSTATE; it++) {
-		if (!ar9300_read_eeprom(ah, cptr, word, COMP_HDR_LEN))
+		if (!read(ah, cptr, word, COMP_HDR_LEN))
 			goto fail;
 
-		if ((word[0] == 0 && word[1] == 0 && word[2] == 0 &&
-		     word[3] == 0) || (word[0] == 0xff && word[1] == 0xff
-				       && word[2] == 0xff && word[3] == 0xff))
+		if (!ar9300_check_header(word))
 			break;
 
 		ar9300_comp_hdr_unpack(word, &code, &reference,
@@ -3272,8 +3351,7 @@ static int ar9300_eeprom_restore_internal(struct ath_hw *ah,
 		}
 
 		osize = length;
-		ar9300_read_eeprom(ah, cptr, word,
-				   COMP_HDR_LEN + osize + COMP_CKSUM_LEN);
+		read(ah, cptr, word, COMP_HDR_LEN + osize + COMP_CKSUM_LEN);
 		checksum = ar9300_comp_cksum(&word[COMP_HDR_LEN], length);
 		mchecksum = word[COMP_HDR_LEN + osize] |
 		    (word[COMP_HDR_LEN + osize + 1] << 8);