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, 414 insertions, 0 deletions

diff --git a/drivers/net/wireless/mediatek/mt7601u/eeprom.c b/drivers/net/wireless/mediatek/mt7601u/eeprom.c
new file mode 100644
index 000000000000..ce3837f270f0
--- /dev/null
+++ b/drivers/net/wireless/mediatek/mt7601u/eeprom.c
@@ -0,0 +1,414 @@
+/*
+ * 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.
+ */
+
+#include <linux/of.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/etherdevice.h>
+#include <asm/unaligned.h>
+#include "mt7601u.h"
+#include "eeprom.h"
+
+static bool
+field_valid(u8 val)
+{
+	return val != 0xff;
+}
+
+static s8
+field_validate(u8 val)
+{
+	if (!field_valid(val))
+		return 0;
+
+	return val;
+}
+
+static int
+mt7601u_efuse_read(struct mt7601u_dev *dev, u16 addr, u8 *data,
+		   enum mt7601u_eeprom_access_modes mode)
+{
+	u32 val;
+	int i;
+
+	val = mt76_rr(dev, MT_EFUSE_CTRL);
+	val &= ~(MT_EFUSE_CTRL_AIN |
+		 MT_EFUSE_CTRL_MODE);
+	val |= MT76_SET(MT_EFUSE_CTRL_AIN, addr & ~0xf) |
+	       MT76_SET(MT_EFUSE_CTRL_MODE, mode) |
+	       MT_EFUSE_CTRL_KICK;
+	mt76_wr(dev, MT_EFUSE_CTRL, val);
+
+	if (!mt76_poll(dev, MT_EFUSE_CTRL, MT_EFUSE_CTRL_KICK, 0, 1000))
+		return -ETIMEDOUT;
+
+	val = mt76_rr(dev, MT_EFUSE_CTRL);
+	if ((val & MT_EFUSE_CTRL_AOUT) == MT_EFUSE_CTRL_AOUT) {
+		/* Parts of eeprom not in the usage map (0x80-0xc0,0xf0)
+		 * will not return valid data but it's ok.
+		 */
+		memset(data, 0xff, 16);
+		return 0;
+	}
+
+	for (i = 0; i < 4; i++) {
+		val = mt76_rr(dev, MT_EFUSE_DATA(i));
+		put_unaligned_le32(val, data + 4 * i);
+	}
+
+	return 0;
+}
+
+static int
+mt7601u_efuse_physical_size_check(struct mt7601u_dev *dev)
+{
+	const int map_reads = DIV_ROUND_UP(MT_EFUSE_USAGE_MAP_SIZE, 16);
+	u8 data[map_reads * 16];
+	int ret, i;
+	u32 start = 0, end = 0, cnt_free;
+
+	for (i = 0; i < map_reads; i++) {
+		ret = mt7601u_efuse_read(dev, MT_EE_USAGE_MAP_START + i * 16,
+					 data + i * 16, MT_EE_PHYSICAL_READ);
+		if (ret)
+			return ret;
+	}
+
+	for (i = 0; i < MT_EFUSE_USAGE_MAP_SIZE; i++)
+		if (!data[i]) {
+			if (!start)
+				start = MT_EE_USAGE_MAP_START + i;
+			end = MT_EE_USAGE_MAP_START + i;
+		}
+	cnt_free = end - start + 1;
+
+	if (MT_EFUSE_USAGE_MAP_SIZE - cnt_free < 5) {
+		dev_err(dev->dev, "Error: your device needs default EEPROM file and this driver doesn't support it!\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static bool
+mt7601u_has_tssi(struct mt7601u_dev *dev, u8 *eeprom)
+{
+	u16 nic_conf1 = get_unaligned_le16(eeprom + MT_EE_NIC_CONF_1);
+
+	return ~nic_conf1 && (nic_conf1 & MT_EE_NIC_CONF_1_TX_ALC_EN);
+}
+
+static void
+mt7601u_set_chip_cap(struct mt7601u_dev *dev, u8 *eeprom)
+{
+	u16 nic_conf0 = get_unaligned_le16(eeprom + MT_EE_NIC_CONF_0);
+	u16 nic_conf1 = get_unaligned_le16(eeprom + MT_EE_NIC_CONF_1);
+
+	if (!field_valid(nic_conf1 & 0xff))
+		nic_conf1 &= 0xff00;
+
+	dev->ee->tssi_enabled = mt7601u_has_tssi(dev, eeprom) &&
+				!(nic_conf1 & MT_EE_NIC_CONF_1_TEMP_TX_ALC);
+
+	if (nic_conf1 & MT_EE_NIC_CONF_1_HW_RF_CTRL)
+		dev_err(dev->dev,
+			"Error: this driver does not support HW RF ctrl\n");
+
+	if (!field_valid(nic_conf0 >> 8))
+		return;
+
+	if (MT76_GET(MT_EE_NIC_CONF_0_RX_PATH, nic_conf0) > 1 ||
+	    MT76_GET(MT_EE_NIC_CONF_0_TX_PATH, nic_conf0) > 1)
+		dev_err(dev->dev,
+			"Error: device has more than 1 RX/TX stream!\n");
+}
+
+static int
+mt7601u_set_macaddr(struct mt7601u_dev *dev, const u8 *eeprom)
+{
+	const void *src = eeprom + MT_EE_MAC_ADDR;
+
+	ether_addr_copy(dev->macaddr, src);
+
+	if (!is_valid_ether_addr(dev->macaddr)) {
+		eth_random_addr(dev->macaddr);
+		dev_info(dev->dev,
+			 "Invalid MAC address, using random address %pM\n",
+			 dev->macaddr);
+	}
+
+	mt76_wr(dev, MT_MAC_ADDR_DW0, get_unaligned_le32(dev->macaddr));
+	mt76_wr(dev, MT_MAC_ADDR_DW1, get_unaligned_le16(dev->macaddr + 4) |
+		MT76_SET(MT_MAC_ADDR_DW1_U2ME_MASK, 0xff));
+
+	return 0;
+}
+
+static void mt7601u_set_channel_target_power(struct mt7601u_dev *dev,
+					     u8 *eeprom, u8 max_pwr)
+{
+	u8 trgt_pwr = eeprom[MT_EE_TX_TSSI_TARGET_POWER];
+
+	if (trgt_pwr > max_pwr || !trgt_pwr) {
+		dev_warn(dev->dev, "Error: EEPROM trgt power invalid %hhx!\n",
+			 trgt_pwr);
+		trgt_pwr = 0x20;
+	}
+
+	memset(dev->ee->chan_pwr, trgt_pwr, sizeof(dev->ee->chan_pwr));
+}
+
+static void
+mt7601u_set_channel_power(struct mt7601u_dev *dev, u8 *eeprom)
+{
+	u32 i, val;
+	u8 max_pwr;
+
+	val = mt7601u_rr(dev, MT_TX_ALC_CFG_0);
+	max_pwr = MT76_GET(MT_TX_ALC_CFG_0_LIMIT_0, val);
+
+	if (mt7601u_has_tssi(dev, eeprom)) {
+		mt7601u_set_channel_target_power(dev, eeprom, max_pwr);
+		return;
+	}
+
+	for (i = 0; i < 14; i++) {
+		s8 power = field_validate(eeprom[MT_EE_TX_POWER_OFFSET + i]);
+
+		if (power > max_pwr || power < 0)
+			power = MT7601U_DEFAULT_TX_POWER;
+
+		dev->ee->chan_pwr[i] = power;
+	}
+}
+
+static void
+mt7601u_set_country_reg(struct mt7601u_dev *dev, u8 *eeprom)
+{
+	/* Note: - region 31 is not valid for mt7601u (see rtmp_init.c)
+	 *	 - comments in rtmp_def.h are incorrect (see rt_channel.c)
+	 */
+	static const struct reg_channel_bounds chan_bounds[] = {
+		/* EEPROM country regions 0 - 7 */
+		{  1, 11 },	{  1, 13 },	{ 10,  2 },	{ 10,  4 },
+		{ 14,  1 },	{  1, 14 },	{  3,  7 },	{  5,  9 },
+		/* EEPROM country regions 32 - 33 */
+		{  1, 11 },	{  1, 14 }
+	};
+	u8 val = eeprom[MT_EE_COUNTRY_REGION];
+	int idx = -1;
+
+	if (val < 8)
+		idx = val;
+	if (val > 31 && val < 33)
+		idx = val - 32 + 8;
+
+	if (idx != -1)
+		dev_info(dev->dev,
+			 "EEPROM country region %02hhx (channels %hhd-%hhd)\n",
+			 val, chan_bounds[idx].start,
+			 chan_bounds[idx].start + chan_bounds[idx].num - 1);
+	else
+		idx = 5; /* channels 1 - 14 */
+
+	dev->ee->reg = chan_bounds[idx];
+
+	/* TODO: country region 33 is special - phy should be set to B-mode
+	 *	 before entering channel 14 (see sta/connect.c)
+	 */
+}
+
+static void
+mt7601u_set_rf_freq_off(struct mt7601u_dev *dev, u8 *eeprom)
+{
+	u8 comp;
+
+	dev->ee->rf_freq_off = field_validate(eeprom[MT_EE_FREQ_OFFSET]);
+	comp = field_validate(eeprom[MT_EE_FREQ_OFFSET_COMPENSATION]);
+
+	if (comp & BIT(7))
+		dev->ee->rf_freq_off -= comp & 0x7f;
+	else
+		dev->ee->rf_freq_off += comp;
+}
+
+static void
+mt7601u_set_rssi_offset(struct mt7601u_dev *dev, u8 *eeprom)
+{
+	int i;
+	s8 *rssi_offset = dev->ee->rssi_offset;
+
+	for (i = 0; i < 2; i++) {
+		rssi_offset[i] = eeprom[MT_EE_RSSI_OFFSET + i];
+
+		if (rssi_offset[i] < -10 || rssi_offset[i] > 10) {
+			dev_warn(dev->dev,
+				 "Warning: EEPROM RSSI is invalid %02hhx\n",
+				 rssi_offset[i]);
+			rssi_offset[i] = 0;
+		}
+	}
+}
+
+static void
+mt7601u_extra_power_over_mac(struct mt7601u_dev *dev)
+{
+	u32 val;
+
+	val = ((mt7601u_rr(dev, MT_TX_PWR_CFG_1) & 0x0000ff00) >> 8);
+	val |= ((mt7601u_rr(dev, MT_TX_PWR_CFG_2) & 0x0000ff00) << 8);
+	mt7601u_wr(dev, MT_TX_PWR_CFG_7, val);
+
+	val = ((mt7601u_rr(dev, MT_TX_PWR_CFG_4) & 0x0000ff00) >> 8);
+	mt7601u_wr(dev, MT_TX_PWR_CFG_9, val);
+}
+
+static void
+mt7601u_set_power_rate(struct power_per_rate *rate, s8 delta, u8 value)
+{
+	rate->raw = s6_validate(value);
+	rate->bw20 = s6_to_int(value);
+	/* Note: vendor driver does cap the value to s6 right away */
+	rate->bw40 = rate->bw20 + delta;
+}
+
+static void
+mt7601u_save_power_rate(struct mt7601u_dev *dev, s8 delta, u32 val, int i)
+{
+	struct mt7601u_rate_power *t = &dev->ee->power_rate_table;
+
+	switch (i) {
+	case 0:
+		mt7601u_set_power_rate(&t->cck[0], delta, (val >> 0) & 0xff);
+		mt7601u_set_power_rate(&t->cck[1], delta, (val >> 8) & 0xff);
+		/* Save cck bw20 for fixups of channel 14 */
+		dev->ee->real_cck_bw20[0] = t->cck[0].bw20;
+		dev->ee->real_cck_bw20[1] = t->cck[1].bw20;
+
+		mt7601u_set_power_rate(&t->ofdm[0], delta, (val >> 16) & 0xff);
+		mt7601u_set_power_rate(&t->ofdm[1], delta, (val >> 24) & 0xff);
+		break;
+	case 1:
+		mt7601u_set_power_rate(&t->ofdm[2], delta, (val >> 0) & 0xff);
+		mt7601u_set_power_rate(&t->ofdm[3], delta, (val >> 8) & 0xff);
+		mt7601u_set_power_rate(&t->ht[0], delta, (val >> 16) & 0xff);
+		mt7601u_set_power_rate(&t->ht[1], delta, (val >> 24) & 0xff);
+		break;
+	case 2:
+		mt7601u_set_power_rate(&t->ht[2], delta, (val >> 0) & 0xff);
+		mt7601u_set_power_rate(&t->ht[3], delta, (val >> 8) & 0xff);
+		break;
+	}
+}
+
+static s8
+get_delta(u8 val)
+{
+	s8 ret;
+
+	if (!field_valid(val) || !(val & BIT(7)))
+		return 0;
+
+	ret = val & 0x1f;
+	if (ret > 8)
+		ret = 8;
+	if (val & BIT(6))
+		ret = -ret;
+
+	return ret;
+}
+
+static void
+mt7601u_config_tx_power_per_rate(struct mt7601u_dev *dev, u8 *eeprom)
+{
+	u32 val;
+	s8 bw40_delta;
+	int i;
+
+	bw40_delta = get_delta(eeprom[MT_EE_TX_POWER_DELTA_BW40]);
+
+	for (i = 0; i < 5; i++) {
+		val = get_unaligned_le32(eeprom + MT_EE_TX_POWER_BYRATE(i));
+
+		mt7601u_save_power_rate(dev, bw40_delta, val, i);
+
+		if (~val)
+			mt7601u_wr(dev, MT_TX_PWR_CFG_0 + i * 4, val);
+	}
+
+	mt7601u_extra_power_over_mac(dev);
+}
+
+static void
+mt7601u_init_tssi_params(struct mt7601u_dev *dev, u8 *eeprom)
+{
+	struct tssi_data *d = &dev->ee->tssi_data;
+
+	if (!dev->ee->tssi_enabled)
+		return;
+
+	d->slope = eeprom[MT_EE_TX_TSSI_SLOPE];
+	d->tx0_delta_offset = eeprom[MT_EE_TX_TSSI_OFFSET] * 1024;
+	d->offset[0] = eeprom[MT_EE_TX_TSSI_OFFSET_GROUP];
+	d->offset[1] = eeprom[MT_EE_TX_TSSI_OFFSET_GROUP + 1];
+	d->offset[2] = eeprom[MT_EE_TX_TSSI_OFFSET_GROUP + 2];
+}
+
+int
+mt7601u_eeprom_init(struct mt7601u_dev *dev)
+{
+	u8 *eeprom;
+	int i, ret;
+
+	ret = mt7601u_efuse_physical_size_check(dev);
+	if (ret)
+		return ret;
+
+	dev->ee = devm_kzalloc(dev->dev, sizeof(*dev->ee), GFP_KERNEL);
+	if (!dev->ee)
+		return -ENOMEM;
+
+	eeprom = kmalloc(MT7601U_EEPROM_SIZE, GFP_KERNEL);
+	if (!eeprom)
+		return -ENOMEM;
+
+	for (i = 0; i + 16 <= MT7601U_EEPROM_SIZE; i += 16) {
+		ret = mt7601u_efuse_read(dev, i, eeprom + i, MT_EE_READ);
+		if (ret)
+			goto out;
+	}
+
+	if (eeprom[MT_EE_VERSION_EE] > MT7601U_EE_MAX_VER)
+		dev_warn(dev->dev,
+			 "Warning: unsupported EEPROM version %02hhx\n",
+			 eeprom[MT_EE_VERSION_EE]);
+	dev_info(dev->dev, "EEPROM ver:%02hhx fae:%02hhx\n",
+		 eeprom[MT_EE_VERSION_EE], eeprom[MT_EE_VERSION_FAE]);
+
+	mt7601u_set_macaddr(dev, eeprom);
+	mt7601u_set_chip_cap(dev, eeprom);
+	mt7601u_set_channel_power(dev, eeprom);
+	mt7601u_set_country_reg(dev, eeprom);
+	mt7601u_set_rf_freq_off(dev, eeprom);
+	mt7601u_set_rssi_offset(dev, eeprom);
+	dev->ee->ref_temp = eeprom[MT_EE_REF_TEMP];
+	dev->ee->lna_gain = eeprom[MT_EE_LNA_GAIN];
+
+	mt7601u_config_tx_power_per_rate(dev, eeprom);
+
+	mt7601u_init_tssi_params(dev, eeprom);
+out:
+	kfree(eeprom);
+	return ret;
+}