add mt7601u driver

Add support for the simplest of MediaTek Wi-Fi devices - MT7601U.
It is a single stream bgn chip with no bells or whistles.
This driver is partially based on Felix's mt76 but IMHO it doesn't
make sense to merge the two right now because MT7601U is a design
somewhere between old Ralink devices and new Mediatek chips.  There
wouldn't be all that much code sharing with the devices mt76 supports.
Situation may obviously change when someone decides to extend m76 with
support for the more recent USB dongles.

The driver supports only station mode.  I'm hoping to add AP support
when time allows.

This driver sat on GitHub for quite a while and got some testing there:
http://github.com/kuba-moo/mt7601u

Signed-off-by: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

1 files changed, 151 insertions, 0 deletions

diff --git a/drivers/net/wireless/mediatek/mt7601u/eeprom.h b/drivers/net/wireless/mediatek/mt7601u/eeprom.h
new file mode 100644
index 000000000000..662d12703b69
--- /dev/null
+++ b/drivers/net/wireless/mediatek/mt7601u/eeprom.h
@@ -0,0 +1,151 @@
+/*
+ * Copyright (C) 2014 Felix Fietkau <nbd@openwrt.org>
+ * Copyright (C) 2015 Jakub Kicinski <kubakici@wp.pl>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __MT7601U_EEPROM_H
+#define __MT7601U_EEPROM_H
+
+struct mt7601u_dev;
+
+#define MT7601U_EE_MAX_VER			0x0c
+#define MT7601U_EEPROM_SIZE			256
+
+#define MT7601U_DEFAULT_TX_POWER		6
+
+enum mt76_eeprom_field {
+	MT_EE_CHIP_ID =				0x00,
+	MT_EE_VERSION_FAE =			0x02,
+	MT_EE_VERSION_EE =			0x03,
+	MT_EE_MAC_ADDR =			0x04,
+	MT_EE_NIC_CONF_0 =			0x34,
+	MT_EE_NIC_CONF_1 =			0x36,
+	MT_EE_COUNTRY_REGION =			0x39,
+	MT_EE_FREQ_OFFSET =			0x3a,
+	MT_EE_NIC_CONF_2 =			0x42,
+
+	MT_EE_LNA_GAIN =			0x44,
+	MT_EE_RSSI_OFFSET =			0x46,
+
+	MT_EE_TX_POWER_DELTA_BW40 =		0x50,
+	MT_EE_TX_POWER_OFFSET =			0x52,
+
+	MT_EE_TX_TSSI_SLOPE =			0x6e,
+	MT_EE_TX_TSSI_OFFSET_GROUP =		0x6f,
+	MT_EE_TX_TSSI_OFFSET =			0x76,
+
+	MT_EE_TX_TSSI_TARGET_POWER =		0xd0,
+	MT_EE_REF_TEMP =			0xd1,
+	MT_EE_FREQ_OFFSET_COMPENSATION =	0xdb,
+	MT_EE_TX_POWER_BYRATE_BASE =		0xde,
+
+	MT_EE_USAGE_MAP_START =			0x1e0,
+	MT_EE_USAGE_MAP_END =			0x1fc,
+};
+
+#define MT_EE_NIC_CONF_0_RX_PATH		GENMASK(3, 0)
+#define MT_EE_NIC_CONF_0_TX_PATH		GENMASK(7, 4)
+#define MT_EE_NIC_CONF_0_BOARD_TYPE		GENMASK(13, 12)
+
+#define MT_EE_NIC_CONF_1_HW_RF_CTRL		BIT(0)
+#define MT_EE_NIC_CONF_1_TEMP_TX_ALC		BIT(1)
+#define MT_EE_NIC_CONF_1_LNA_EXT_2G		BIT(2)
+#define MT_EE_NIC_CONF_1_LNA_EXT_5G		BIT(3)
+#define MT_EE_NIC_CONF_1_TX_ALC_EN		BIT(13)
+
+#define MT_EE_NIC_CONF_2_RX_STREAM		GENMASK(3, 0)
+#define MT_EE_NIC_CONF_2_TX_STREAM		GENMASK(7, 4)
+#define MT_EE_NIC_CONF_2_HW_ANTDIV		BIT(8)
+#define MT_EE_NIC_CONF_2_XTAL_OPTION		GENMASK(10, 9)
+#define MT_EE_NIC_CONF_2_TEMP_DISABLE		BIT(11)
+#define MT_EE_NIC_CONF_2_COEX_METHOD		GENMASK(15, 13)
+
+#define MT_EE_TX_POWER_BYRATE(i)		(MT_EE_TX_POWER_BYRATE_BASE + \
+						 (i) * 4)
+
+#define MT_EFUSE_USAGE_MAP_SIZE			(MT_EE_USAGE_MAP_END -	\
+						 MT_EE_USAGE_MAP_START + 1)
+
+enum mt7601u_eeprom_access_modes {
+	MT_EE_READ = 0,
+	MT_EE_PHYSICAL_READ = 1,
+};
+
+struct power_per_rate  {
+	u8 raw;  /* validated s6 value */
+	s8 bw20; /* sign-extended int */
+	s8 bw40; /* sign-extended int */
+};
+
+/* Power per rate - one value per two rates */
+struct mt7601u_rate_power {
+	struct power_per_rate cck[2];
+	struct power_per_rate ofdm[4];
+	struct power_per_rate ht[4];
+};
+
+struct reg_channel_bounds {
+	u8 start;
+	u8 num;
+};
+
+struct mt7601u_eeprom_params {
+	bool tssi_enabled;
+	u8 rf_freq_off;
+	s8 rssi_offset[2];
+	s8 ref_temp;
+	s8 lna_gain;
+
+	u8 chan_pwr[14];
+	struct mt7601u_rate_power power_rate_table;
+	s8 real_cck_bw20[2];
+
+	/* TSSI stuff - only with internal TX ALC */
+	struct tssi_data {
+		int tx0_delta_offset;
+		u8 slope;
+		u8 offset[3];
+	} tssi_data;
+
+	struct reg_channel_bounds reg;
+};
+
+int mt7601u_eeprom_init(struct mt7601u_dev *dev);
+
+static inline u32 s6_validate(u32 reg)
+{
+	WARN_ON(reg & ~GENMASK(5, 0));
+	return reg & GENMASK(5, 0);
+}
+
+static inline int s6_to_int(u32 reg)
+{
+	int s6;
+
+	s6 = s6_validate(reg);
+	if (s6 & BIT(5))
+		s6 -= BIT(6);
+
+	return s6;
+}
+
+static inline u32 int_to_s6(int val)
+{
+	if (val < -0x20)
+		return 0x20;
+	if (val > 0x1f)
+		return 0x1f;
+
+	return val & 0x3f;
+}
+
+#endif