From c8ba8b60275ff99f5103142db5b167354c5b94c0 Mon Sep 17 00:00:00 2001
From: Yingyuan Zhu <yingyuan.zhu@amlogic.com>
Date: Wed, 24 Apr 2019 17:50:29 +0800
Subject: [PATCH] tm2: add SWD interface [3/3]

PD#SWPL-5647

Problem:
tm2 does not support SWD mode.

Solution:
add code to support SWD mode.

Verify:
test pass on ab311

Change-Id: If85a050b5033242200dd7163a8391e71960621f0
Signed-off-by: Yingyuan Zhu <yingyuan.zhu@amlogic.com>
---
 arch/arm/boot/dts/amlogic/mesontm2.dtsi   | 13 +++++++++++--
 arch/arm64/boot/dts/amlogic/mesontm2.dtsi | 13 +++++++++++--
 drivers/amlogic/jtag/meson_jtag.c         | 22 ++++++++++++++++++++--
 include/linux/amlogic/jtag.h              |  1 +
 4 files changed, 43 insertions(+), 6 deletions(-)

diff --git a/arch/arm/boot/dts/amlogic/mesontm2.dtsi b/arch/arm/boot/dts/amlogic/mesontm2.dtsi
index 6d195d2..c15290f 100644
--- a/arch/arm/boot/dts/amlogic/mesontm2.dtsi
+++ b/arch/arm/boot/dts/amlogic/mesontm2.dtsi
@@ -523,9 +523,10 @@
 	jtag {
 		compatible = "amlogic, jtag";
 		status = "okay";
-		select = "disable"; /* disable/apao */
-		pinctrl-names="jtag_apao_pins";
+		select = "disable"; /* disable/apao/swd_apao */
+		pinctrl-names="jtag_apao_pins", "jtag_swd_apao_pins";
 		pinctrl-0=<&jtag_apao_pins>;
+		pinctrl-1=<&jtag_swd_apao_pins>;
 	};
 
 	saradc:saradc {
@@ -1814,6 +1815,14 @@
 			function = "jtag_a";
 		};
 	};
+
+	jtag_swd_apao_pins:swd_apao_pin {
+		mux {
+			groups = "swclk",
+			"swdio";
+			function = "sw";
+		};
+	};
 };
 
 &pinctrl_periphs {
diff --git a/arch/arm64/boot/dts/amlogic/mesontm2.dtsi b/arch/arm64/boot/dts/amlogic/mesontm2.dtsi
index 5690f3d..bcbb4356 100644
--- a/arch/arm64/boot/dts/amlogic/mesontm2.dtsi
+++ b/arch/arm64/boot/dts/amlogic/mesontm2.dtsi
@@ -512,9 +512,10 @@
 	jtag {
 		compatible = "amlogic, jtag";
 		status = "okay";
-		select = "disable"; /* disable/apao */
-		pinctrl-names="jtag_apao_pins";
+		select = "disable"; /* disable/apao/swd_apao */
+		pinctrl-names="jtag_apao_pins", "jtag_swd_apao_pins";
 		pinctrl-0=<&jtag_apao_pins>;
+		pinctrl-1=<&jtag_swd_apao_pins>;
 	};
 
 	saradc:saradc {
@@ -1803,6 +1804,14 @@
 			function = "jtag_a";
 		};
 	};
+
+	jtag_swd_apao_pins:swd_apao_pin {
+		mux {
+			groups = "swclk",
+			"swdio";
+			function = "sw";
+		};
+	};
 };
 
 &pinctrl_periphs {
diff --git a/drivers/amlogic/jtag/meson_jtag.c b/drivers/amlogic/jtag/meson_jtag.c
index a080ef5..be0f0ce 100644
--- a/drivers/amlogic/jtag/meson_jtag.c
+++ b/drivers/amlogic/jtag/meson_jtag.c
@@ -96,6 +96,8 @@ static inline char *select_to_name(int select)
 		return "apao";
 	case AMLOGIC_JTAG_APEE:
 		return "apee";
+	case AMLOGIC_SWD_APAO:
+		return "swd_apao";
 	default:
 		return "disable";
 	}
@@ -111,6 +113,8 @@ static inline int name_to_select(const char *s)
 		select = AMLOGIC_JTAG_APAO;
 	else if (!strncmp(s, "apee", 4))
 		select = AMLOGIC_JTAG_APEE;
+	else if (!strncmp(s, "swd_apao", 8))
+		select = AMLOGIC_SWD_APAO;
 	else {
 		pr_err("unknown select: %s\n", s);
 		select = AMLOGIC_JTAG_DISABLE;
@@ -168,7 +172,7 @@ static int __init setup_jtag(char *p)
 }
 
 /*
- * jtag=[apao|apee]
+ * jtag=[apao|apee|swd_apao]
  * jtag=[apao|apee]{,[0|1]}
  *
  * [apao|apee]: jtag domain
@@ -356,6 +360,20 @@ static int aml_jtag_setup(struct aml_jtag_dev *jdev)
 			return -EINVAL;
 		}
 		break;
+	case AMLOGIC_SWD_APAO:
+		s = pinctrl_lookup_state(jdev->jtag_pinctrl,
+					 "jtag_swd_apao_pins");
+		if (IS_ERR_OR_NULL(s)) {
+			dev_err(&jdev->pdev->dev,
+					"could not get swd_apao_pins state\n");
+			return -EINVAL;
+		}
+		ret = pinctrl_select_state(jdev->jtag_pinctrl, s);
+		if (ret) {
+			dev_err(&jdev->pdev->dev, "failed to set pinctrl\n");
+			return -EINVAL;
+		}
+		break;
 	default:
 		if (old_select != AMLOGIC_JTAG_DISABLE) {
 			devm_pinctrl_put(jdev->jtag_pinctrl);
@@ -380,7 +398,7 @@ static ssize_t jtag_select_show(struct class *cls,
 	len += sprintf(buf + len, "current select: %s\n\n",
 			select_to_name(global_select));
 	len += sprintf(buf + len, "usage:\n");
-	len += sprintf(buf + len, "    echo [apao|apee] > select\n");
+	len += sprintf(buf + len, "    echo [apao|apee|swd_apao] > select\n");
 	len += sprintf(buf + len, "    echo [apao|apee]{,[0|1]} > select\n");
 
 	return len;
diff --git a/include/linux/amlogic/jtag.h b/include/linux/amlogic/jtag.h
index 8497f5c..6db6e26 100644
--- a/include/linux/amlogic/jtag.h
+++ b/include/linux/amlogic/jtag.h
@@ -26,6 +26,7 @@
 #define AMLOGIC_JTAG_DISABLE		(-1)
 #define AMLOGIC_JTAG_APAO			2
 #define AMLOGIC_JTAG_APEE			3
+#define AMLOGIC_SWD_APAO			10
 
 #define AMLOGIC_JTAG_ON			0x82000040
 #define AMLOGIC_JTAG_OFF		0x82000041
-- 
2.7.4