From 0fce1109f894ec7fcd72cb098843a1eff786716a Mon Sep 17 00:00:00 2001
From: Daniel Golle <daniel@makrotopia.org>
Date: Fri, 16 Sep 2022 20:49:42 +0100
Subject: [PATCH 16/16] rt2x00: import support for external LNA on MT7620
To: linux-wireless@vger.kernel.org,
    Stanislaw Gruszka <stf_xl@wp.pl>,
    Helmut Schaa <helmut.schaa@googlemail.com>
Cc: Kalle Valo <kvalo@kernel.org>,
    David S. Miller <davem@davemloft.net>,
    Eric Dumazet <edumazet@google.com>,
    Jakub Kicinski <kuba@kernel.org>,
    Paolo Abeni <pabeni@redhat.com>,
    Johannes Berg <johannes.berg@intel.com>

In order to carry out calibration on boards with ePA or eLNA the PA pin
needs to be switch to GPIO mode on MT7620. Implement that by selecting
pinctrl state "pa_gpio" which should be defined for MT7620 boards with
eLNA or ePA beside the "default" state.

Reported-by: Serge Vasilugin <vasilugin@yandex.ru>
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
 .../net/wireless/ralink/rt2x00/rt2800lib.c    | 58 +++++++++++++++++++
 drivers/net/wireless/ralink/rt2x00/rt2x00.h   |  5 ++
 .../net/wireless/ralink/rt2x00/rt2x00soc.c    | 15 +++++
 3 files changed, 78 insertions(+)

--- a/drivers/net/wireless/ralink/rt2x00/rt2800lib.c
+++ b/drivers/net/wireless/ralink/rt2x00/rt2800lib.c
@@ -305,6 +305,24 @@ static void rt2800_rf_write(struct rt2x0
 	mutex_unlock(&rt2x00dev->csr_mutex);
 }
 
+void rt6352_enable_pa_pin(struct rt2x00_dev *rt2x00dev, int enable)
+{
+	if (!rt2x00dev->pinctrl)
+		return;
+
+	if (enable) {
+		if (!rt2x00dev->pins_default)
+			return;
+
+		pinctrl_select_state(rt2x00dev->pinctrl, rt2x00dev->pins_default);
+	} else {
+		if (!rt2x00dev->pins_pa_gpio)
+			return;
+
+		pinctrl_select_state(rt2x00dev->pinctrl, rt2x00dev->pins_pa_gpio);
+	}
+}
+
 static const unsigned int rt2800_eeprom_map[EEPROM_WORD_COUNT] = {
 	[EEPROM_CHIP_ID]		= 0x0000,
 	[EEPROM_VERSION]		= 0x0001,
@@ -10407,8 +10425,10 @@ static void rt2800_calibration_rt6352(st
 	u32 reg;
 
 	if (rt2x00_has_cap_external_pa(rt2x00dev) ||
-	    rt2x00_has_cap_external_lna_bg(rt2x00dev))
+	    rt2x00_has_cap_external_lna_bg(rt2x00dev)) {
+		rt6352_enable_pa_pin(rt2x00dev, 0);
 		rt2800_restore_rf_bbp_rt6352(rt2x00dev);
+	}
 
 	rt2800_r_calibration(rt2x00dev);
 	rt2800_rf_self_txdc_cal(rt2x00dev);
@@ -10426,6 +10446,8 @@ static void rt2800_calibration_rt6352(st
 	    !rt2x00_has_cap_external_lna_bg(rt2x00dev))
 		return;
 
+	rt6352_enable_pa_pin(rt2x00dev, 1);
+
 	if (rt2x00_has_cap_external_pa(rt2x00dev)) {
 		reg = rt2800_register_read(rt2x00dev, RF_CONTROL3);
 		reg |= 0x00000101;
--- a/drivers/net/wireless/ralink/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/ralink/rt2x00/rt2x00.h
@@ -28,6 +28,7 @@
 #include <linux/average.h>
 #include <linux/usb.h>
 #include <linux/clk.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/rt2x00_platform.h>
 
 #include <net/mac80211.h>
@@ -1027,6 +1028,11 @@ struct rt2x00_dev {
 
 	/* Clock for System On Chip devices. */
 	struct clk *clk;
+
+	/* pinctrl and states for System On Chip devices with PA/LNA. */
+	struct pinctrl *pinctrl;
+	struct pinctrl_state *pins_default;
+	struct pinctrl_state *pins_pa_gpio;
 };
 
 struct rt2x00_bar_list_entry {
--- a/drivers/net/wireless/ralink/rt2x00/rt2x00soc.c
+++ b/drivers/net/wireless/ralink/rt2x00/rt2x00soc.c
@@ -97,6 +97,21 @@ int rt2x00soc_probe(struct platform_devi
 	if (retval)
 		goto exit_free_reg;
 
+	rt2x00dev->pinctrl = devm_pinctrl_get(&pdev->dev);
+	if (IS_ERR(rt2x00dev->pinctrl)) {
+		rt2x00dev->pinctrl = NULL;
+		rt2x00dev->pins_default = NULL;
+		rt2x00dev->pins_pa_gpio = NULL;
+	} else {
+		rt2x00dev->pins_default = pinctrl_lookup_state(rt2x00dev->pinctrl, "default");
+		if (IS_ERR(rt2x00dev->pins_default))
+			rt2x00dev->pins_default = NULL;
+
+		rt2x00dev->pins_pa_gpio = pinctrl_lookup_state(rt2x00dev->pinctrl, "pa_gpio");
+		if (IS_ERR(rt2x00dev->pins_pa_gpio))
+			rt2x00dev->pins_pa_gpio = NULL;
+	}
+
 	return 0;
 
 exit_free_reg: