bcm53xx: enable PWM for bcm53xx

The Meraki MR32 (BCM53016A1) uses the pwm to drive the
tricolor LED. The driver has been available in upstream
for a long time. Only the Device-Tree definition was
missing, but it has been queued recently.

Signed-off-by: Christian Lamparter <[email protected]>

target/linux/bcm53xx/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 ARCH:=arm
 BOARD:=bcm53xx
 BOARDNAME:=Broadcom BCM47xx/53xx (ARM)
-FEATURES:=squashfs nand usb pci pcie gpio
+FEATURES:=squashfs nand usb pci pcie gpio pwm
 CPU_TYPE:=cortex-a9
 SUBTARGETS:=generic
 

target/linux/bcm53xx/config-5.4

@@ -308,6 +308,9 @@ CONFIG_PINCTRL=y
 # CONFIG_PINCTRL_IPROC_GPIO is not set
 CONFIG_PINCTRL_NS=y
 # CONFIG_PINCTRL_NS2_MUX is not set
+CONFIG_PWM=y
+CONFIG_PWM_BCM_IPROC=y
+CONFIG_PWM_SYSFS=y
 CONFIG_RATIONAL=y
 CONFIG_RCU_NEED_SEGCBLIST=y
 CONFIG_RCU_STALL_COMMON=y

target/linux/bcm53xx/patches-5.4/033-v5.10-ARM-dts-BCM5301X-Specify-PWM-in-the-DT.patch

@@ -0,0 +1,48 @@
+From 0ea4b29d149586667d96767f1fc8e57ee942c1b0 Mon Sep 17 00:00:00 2001
+From: Christian Lamparter <[email protected]>
+Date: Sat, 22 Aug 2020 18:19:19 +0200
+Subject: [PATCH] ARM: dts: BCM5301X: Specify PWM in the DT
+
+The BCM53016 in the Meraki MR32 uses the on-chip PWM
+controller to drive a tri-color RGB LED. Since I plan
+to use the PWM, I made a label for the pwm's pinmux
+node. This way, it can be easily referenced.... And
+Also included a label for the i2c since I'm going to
+need it in the future too.
+
+Signed-off-by: Christian Lamparter <[email protected]>
+Acked-by: Scott Branden <[email protected]>
+Signed-off-by: Florian Fainelli <[email protected]>
+
+--- a/arch/arm/boot/dts/bcm5301x.dtsi
++++ b/arch/arm/boot/dts/bcm5301x.dtsi
+@@ -350,6 +350,14 @@
+ 		};
+ 	};
+ 
++	pwm: pwm@18002000 {
++		compatible = "brcm,iproc-pwm";
++		reg = <0x18002000 0x28>;
++		clocks = <&osc>;
++		#pwm-cells = <3>;
++		status = "disabled";
++	};
++
+ 	mdio: mdio@18003000 {
+ 		compatible = "brcm,iproc-mdio";
+ 		reg = <0x18003000 0x8>;
+@@ -417,12 +425,12 @@
+ 					function = "spi";
+ 				};
+ 
+-				i2c {
++				pinmux_i2c: i2c {
+ 					groups = "i2c_grp";
+ 					function = "i2c";
+ 				};
+ 
+-				pwm {
++				pinmux_pwm: pwm {
+ 					groups = "pwm0_grp", "pwm1_grp",
+ 						 "pwm2_grp", "pwm3_grp";
+ 					function = "pwm";