From 39610b254efed98754efcc85a85c0f647c7d9bd0 Mon Sep 17 00:00:00 2001
From: rdon <you@example.com>
Date: Sat, 30 May 2026 18:54:25 +0900
Subject: [PATCH 1/2] rp2: allow SPI transmit-only without SDI

---
 src/machine/machine_rp2_2040.go  | 4 ++--
 src/machine/machine_rp2_2350a.go | 4 ++--
 src/machine/machine_rp2_2350b.go | 4 ++--
 src/machine/machine_rp2_spi.go   | 4 +++-
 4 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/src/machine/machine_rp2_2040.go b/src/machine/machine_rp2_2040.go
index 78336a3b76..12638a1052 100644
--- a/src/machine/machine_rp2_2040.go
+++ b/src/machine/machine_rp2_2040.go
@@ -130,11 +130,11 @@ func (spi *SPI) validPins(config SPIConfig) error {
 	var okSDI, okSDO, okSCK bool
 	switch spi.Bus {
 	case rp.SPI0:
-		okSDI = config.SDI == 0 || config.SDI == 4 || config.SDI == 16 || config.SDI == 20
+		okSDI = config.SDI == NoPin || config.SDI == 0 || config.SDI == 4 || config.SDI == 16 || config.SDI == 20
 		okSDO = config.SDO == 3 || config.SDO == 7 || config.SDO == 19 || config.SDO == 23
 		okSCK = config.SCK == 2 || config.SCK == 6 || config.SCK == 18 || config.SCK == 22
 	case rp.SPI1:
-		okSDI = config.SDI == 8 || config.SDI == 12 || config.SDI == 24 || config.SDI == 28
+		okSDI = config.SDI == NoPin || config.SDI == 8 || config.SDI == 12 || config.SDI == 24 || config.SDI == 28
 		okSDO = config.SDO == 11 || config.SDO == 15 || config.SDO == 27
 		okSCK = config.SCK == 10 || config.SCK == 14 || config.SCK == 26
 	}
diff --git a/src/machine/machine_rp2_2350a.go b/src/machine/machine_rp2_2350a.go
index 6918d22978..c92e7794f9 100644
--- a/src/machine/machine_rp2_2350a.go
+++ b/src/machine/machine_rp2_2350a.go
@@ -21,11 +21,11 @@ func (spi *SPI) validPins(config SPIConfig) error {
 	var okSDI, okSDO, okSCK bool
 	switch spi.Bus {
 	case rp.SPI0:
-		okSDI = config.SDI == 0 || config.SDI == 4 || config.SDI == 16 || config.SDI == 20
+		okSDI = config.SDI == NoPin || config.SDI == 0 || config.SDI == 4 || config.SDI == 16 || config.SDI == 20
 		okSDO = config.SDO == 3 || config.SDO == 7 || config.SDO == 19 || config.SDO == 23
 		okSCK = config.SCK == 2 || config.SCK == 6 || config.SCK == 18 || config.SCK == 22
 	case rp.SPI1:
-		okSDI = config.SDI == 8 || config.SDI == 12 || config.SDI == 24 || config.SDI == 28
+		okSDI = config.SDI == NoPin || config.SDI == 8 || config.SDI == 12 || config.SDI == 24 || config.SDI == 28
 		okSDO = config.SDO == 11 || config.SDO == 15 || config.SDO == 27
 		okSCK = config.SCK == 10 || config.SCK == 14 || config.SCK == 26
 	}
diff --git a/src/machine/machine_rp2_2350b.go b/src/machine/machine_rp2_2350b.go
index 5f5a76da67..4e7f8e6293 100644
--- a/src/machine/machine_rp2_2350b.go
+++ b/src/machine/machine_rp2_2350b.go
@@ -55,11 +55,11 @@ func (spi *SPI) validPins(config SPIConfig) error {
 	var okSDI, okSDO, okSCK bool
 	switch spi.Bus {
 	case rp.SPI0:
-		okSDI = config.SDI == 0 || config.SDI == 4 || config.SDI == 16 || config.SDI == 20 || config.SDI == 32 || config.SDI == 36
+		okSDI = config.SDI == NoPin || config.SDI == 0 || config.SDI == 4 || config.SDI == 16 || config.SDI == 20 || config.SDI == 32 || config.SDI == 36
 		okSDO = config.SDO == 3 || config.SDO == 7 || config.SDO == 19 || config.SDO == 23 || config.SDO == 35 || config.SDO == 39
 		okSCK = config.SCK == 2 || config.SCK == 6 || config.SCK == 18 || config.SCK == 22 || config.SCK == 34 || config.SCK == 38
 	case rp.SPI1:
-		okSDI = config.SDI == 8 || config.SDI == 12 || config.SDI == 24 || config.SDI == 28 || config.SDI == 40 || config.SDI == 44
+		okSDI = config.SDI == NoPin || config.SDI == 8 || config.SDI == 12 || config.SDI == 24 || config.SDI == 28 || config.SDI == 40 || config.SDI == 44
 		okSDO = config.SDO == 11 || config.SDO == 15 || config.SDO == 27 || config.SDO == 31 || config.SDO == 43 || config.SDO == 47
 		okSCK = config.SCK == 10 || config.SCK == 14 || config.SCK == 26 || config.SCK == 30 || config.SCK == 42 || config.SCK == 46
 	}
diff --git a/src/machine/machine_rp2_spi.go b/src/machine/machine_rp2_spi.go
index 785b8f831b..14ac5bae6a 100644
--- a/src/machine/machine_rp2_spi.go
+++ b/src/machine/machine_rp2_spi.go
@@ -174,7 +174,9 @@ func (spi *SPI) Configure(config SPIConfig) error {
 	// SPI pin configuration
 	config.SCK.setFunc(fnSPI)
 	config.SDO.setFunc(fnSPI)
-	config.SDI.setFunc(fnSPI)
+	if config.SDI != NoPin {
+		config.SDI.setFunc(fnSPI)
+	}
 
 	return spi.initSPI(config)
 }

From 106c55578e75d2d3f7c52c09bbd88714a4d3846e Mon Sep 17 00:00:00 2001
From: rdon <you@example.com>
Date: Sat, 30 May 2026 21:06:17 +0900
Subject: [PATCH 2/2] ci: rerun