overlays: sc16is75x: Add generic SPI overlay

Currently four nearly identical overlays (sc16is750-spi0 / -spi1
and sc16is752-spi0 / -spi1) are provided. Besides the redundant
configuration all of them lack support for other SPI interfaces
than spi0 and spi1.

Thus refactor the common definitions into a generic sc16is75x-spi
overlay which provides support for all known spi / cs combinations.
Also choose the chip type via dtparam rather than different overlay.

Remove the existing overlays, replacing them with rename rules in the
overlay map.

Signed-off-by: Nicolai Buchwitz <n.buchwitz@kunbus.com>
Signed-off-by: Phil Elwell <phil@raspberrypi.com>

Author: nbuchwitz

arch/arm/boot/dts/overlays/Makefile

@@ -250,10 +250,8 @@ dtbo-$(CONFIG_ARCH_BCM2835) += \
 	rra-digidac1-wm8741-audio.dtbo \
 	sainsmart18.dtbo \
 	sc16is750-i2c.dtbo \
-	sc16is750-spi0.dtbo \
 	sc16is752-i2c.dtbo \
-	sc16is752-spi0.dtbo \
-	sc16is752-spi1.dtbo \
+	sc16is75x-spi.dtbo \
 	sdhost.dtbo \
 	sdio.dtbo \
 	sdio-pi5.dtbo \

arch/arm/boot/dts/overlays/README

@@ -4463,11 +4463,9 @@ Params: int_pin                 GPIO used for IRQ (default 24)
 
 
 Name:   sc16is750-spi0
-Info:   Overlay for the NXP SC16IS750 UART with SPI Interface
-        Enables the chip on SPI0.
-Load:   dtoverlay=sc16is750-spi0,<param>=<val>
-Params: int_pin                 GPIO used for IRQ (default 24)
-        xtal                    On-board crystal frequency (default 14745600)
+Info:   This overlay is now deprecated. Use
+        "dtoverlay=sc16is75x-spi,sc16is750,spi0-0,..." instead.
+Load:   <Deprecated>
 
 
 Name:   sc16is752-i2c
@@ -4483,21 +4481,27 @@ Params: int_pin                 GPIO used for IRQ (default 24)
 
 
 Name:   sc16is752-spi0
-Info:   Overlay for the NXP SC16IS752 Dual UART with SPI Interface
-        Enables the chip on SPI0.
-Load:   dtoverlay=sc16is752-spi0,<param>=<val>
-Params: int_pin                 GPIO used for IRQ (default 24)
-        xtal                    On-board crystal frequency (default 14745600)
+Info:   This overlay is now deprecated. Use
+        "dtoverlay=sc16is75x-spi,sc16is752,spi0-0,..." instead.
+Load:   <Deprecated>
 
 
 Name:   sc16is752-spi1
-Info:   Overlay for the NXP SC16IS752 Dual UART with SPI Interface
-        Enables the chip on SPI1.
-        N.B.: spi1 is only accessible on devices with a 40pin header, eg:
-              A+, B+, Zero and PI2 B; as well as the Compute Module.
+Info:   This overlay is now deprecated. Use
+        "dtoverlay=sc16is75x-spi,sc16is752,spi1-0,..." instead.
+Load:   <Deprecated>
 
-Load:   dtoverlay=sc16is752-spi1,<param>=<val>
-Params: int_pin                 GPIO used for IRQ (default 24)
+
+Name:   sc16is75x-spi
+Info:   Overlay for the NXP SC16IS750/2 (Dual) UART with SPI Interface
+        Enables the chip on SPI.
+
+Load:   dtoverlay=sc16is75x-spi,<param>=<val>
+Params: sc16is750               Device is a SC16IS750 UART (default on)
+        sc16is752               Device is a SC16IS752 Dual UART
+        spi<n>-<m>              Configure device at spi<n>, cs<m>
+                                (boolean, required)
+        int_pin                 GPIO used for IRQ (default 24)
         xtal                    On-board crystal frequency (default 14745600)
 
 

arch/arm/boot/dts/overlays/overlay_map.dts

@@ -284,6 +284,22 @@
 		deprecated = "no longer necessary";
 	};
 
+	sc16is750-spi0 {
+		renamed = "sc16is75x-spi,sc16is750,spi0-0";
+	};
+
+	sc16is750-spi1 {
+		renamed = "sc16is75x-spi,sc16is750,spi1-0";
+	};
+
+	sc16is752-spi0 {
+		renamed = "sc16is75x-spi,sc16is752,spi0-0";
+	};
+
+	sc16is752-spi1 {
+		renamed = "sc16is75x-spi,sc16is752,spi1-0";
+	};
+
 	sdhost {
 		bcm2835;
 		bcm2711;