ARC: [plat-arcfpga]: Enabling DeviceTree for Angel4 board

* arc-uart platform device now populated dynamically, using
  of_platform_populate() - applies to any other device whatsoever.

* uart in turn requires incore arc-intc to be also present in DT

* A irq-domain needs to be instantiated for IRQ requests by DT probed
  device (e.g. arc-uart)

TODO: switch over to linear irq domain once all devs have been
      transitioned to DT

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Arnd Bergmann <arnd@arndb.de>

diff --git a/Documentation/devicetree/bindings/arc/interrupts.txt b/Documentation/devicetree/bindings/arc/interrupts.txt
new file mode 100644 (file)
index 0000000..9a5d562
--- /dev/null
+++ b/Documentation/devicetree/bindings/arc/interrupts.txt
@@ -0,0 +1,24 @@
+* ARC700 incore Interrupt Controller
+
+  The core interrupt controller provides 32 prioritised interrupts (2 levels)
+  to ARC700 core.
+
+Properties:
+
+- compatible: "snps,arc700-intc"
+- interrupt-controller: This is an interrupt controller.
+- #interrupt-cells: Must be <1>.
+
+  Single Cell "interrupts" property of a device specifies the IRQ number
+  between 0 to 31
+
+  intc accessed via the special ARC AUX register interface, hence "reg" property
+  is not specified.
+
+Example:
+
+       intc: interrupt-controller {
+               compatible = "snps,arc700-intc";
+               interrupt-controller;
+               #interrupt-cells = <1>;
+       };

diff --git a/arch/arc/boot/dts/Makefile b/arch/arc/boot/dts/Makefile
index 17dc7b8b05fa5225c1058ba62cfebd7db6c84431..5776835d583f58a7e7776463a6ce552b503c9a17 100644 (file)
--- a/arch/arc/boot/dts/Makefile
+++ b/arch/arc/boot/dts/Makefile
@@ -1,5 +1,5 @@
 # Built-in dtb
-builtindtb-y           := skeleton
+builtindtb-y           := angel4
 
 ifneq ($(CONFIG_ARC_BUILTIN_DTB_NAME),"")
        builtindtb-y    := $(patsubst "%",%,$(CONFIG_ARC_BUILTIN_DTB_NAME))

diff --git a/arch/arc/boot/dts/angel4.dts b/arch/arc/boot/dts/angel4.dts
new file mode 100644 (file)
index 0000000..4c188d5
--- /dev/null
+++ b/arch/arc/boot/dts/angel4.dts
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+/dts-v1/;
+
+/include/ "skeleton.dtsi"
+
+/ {
+       compatible = "snps,arc-angel4";
+       clock-frequency = <80000000>;   /* 80 MHZ */
+       #address-cells = <1>;
+       #size-cells = <1>;
+       interrupt-parent = <&intc>;
+
+       chosen {
+               bootargs = "console=ttyARC0,115200n8";
+       };
+
+       aliases {
+               serial0 = &arcuart0;
+       };
+
+       memory {
+               device_type = "memory";
+               reg = <0x00000000 0x10000000>;  /* 256M */
+       };
+
+       fpga {
+               compatible = "simple-bus";
+               #address-cells = <1>;
+               #size-cells = <1>;
+
+               /* child and parent address space 1:1 mapped */
+               ranges;
+
+               intc: interrupt-controller {
+                       compatible = "snps,arc700-intc";
+                       interrupt-controller;
+                       #interrupt-cells = <1>;
+               };
+
+               arcuart0: serial@c0fc1000 {
+                       compatible = "snps,arc-uart";
+                       reg = <0xc0fc1000 0x100>;
+                       interrupts = <5>;
+                       clock-frequency = <80000000>;
+                       baud = <115200>;
+                       status = "okay";
+               };
+       };
+};

diff --git a/arch/arc/boot/dts/skeleton.dtsi b/arch/arc/boot/dts/skeleton.dtsi
index eb8b77367352628c126ac8410bb03b0985915f4b..a870bdd5e404ca386bb2d8d5efd6b454677f0eae 100644 (file)
--- a/arch/arc/boot/dts/skeleton.dtsi
+++ b/arch/arc/boot/dts/skeleton.dtsi
@@ -18,6 +18,18 @@
        #size-cells = <1>;
        chosen { };
        aliases { };
+
+       cpus {
+               #address-cells = <1>;
+               #size-cells = <0>;
+
+               cpu@0 {
+                       device_type = "cpu";
+                       compatible = "snps,arc770d";
+                       reg = <0>;
+               };
+       };
+
        memory {
                device_type = "memory";
                reg = <0x00000000 0x10000000>;  /* 256M */

diff --git a/arch/arc/kernel/irq.c b/arch/arc/kernel/irq.c
index 2f399eb88f9d973653f692030fd38ee32615aa19..3c18e66386c78a4e8e494209b79e2fe279f47a1b 100644 (file)
--- a/arch/arc/kernel/irq.c
+++ b/arch/arc/kernel/irq.c
@@ -9,6 +9,8 @@
 
 #include <linux/interrupt.h>
 #include <linux/module.h>
+#include <linux/of.h>
+#include <linux/irqdomain.h>
 #include <asm/sections.h>
 #include <asm/irq.h>
 
@@ -59,16 +61,40 @@ static struct irq_chip onchip_intc = {
        .irq_unmask     = arc_unmask_irq,
 };
 
+static int arc_intc_domain_map(struct irq_domain *d, unsigned int irq,
+                               irq_hw_number_t hw)
+{
+       if (irq == TIMER0_IRQ)
+               irq_set_chip_and_handler(irq, &onchip_intc, handle_percpu_irq);
+       else
+               irq_set_chip_and_handler(irq, &onchip_intc, handle_level_irq);
+
+       return 0;
+}
+
+static const struct irq_domain_ops arc_intc_domain_ops = {
+       .xlate = irq_domain_xlate_onecell,
+       .map = arc_intc_domain_map,
+};
+
+static struct irq_domain *root_domain;
+
 void __init init_onchip_IRQ(void)
 {
-       int i;
+       struct device_node *intc = NULL;
+
+       intc = of_find_compatible_node(NULL, NULL, "snps,arc700-intc");
+       if(!intc)
+               panic("DeviceTree Missing incore intc\n");
+
+       root_domain = irq_domain_add_legacy(intc, NR_IRQS, 0, 0,
+                                           &arc_intc_domain_ops, NULL);
 
-       for (i = 0; i < NR_IRQS; i++)
-               irq_set_chip_and_handler(i, &onchip_intc, handle_level_irq);
+       if (!root_domain)
+               panic("root irq domain not avail\n");
 
-#ifdef CONFIG_SMP
-       irq_set_chip_and_handler(TIMER0_IRQ, &onchip_intc, handle_percpu_irq);
-#endif
+       /* with this we don't need to export root_domain */
+       irq_set_default_host(root_domain);
 }
 
 /*

diff --git a/arch/arc/plat-arcfpga/platform.c b/arch/arc/plat-arcfpga/platform.c
index 5388b31e2eadc7508445bfe8416759a2eab43fdd..33bcac8bd6b81333eb55eea394ab52f7a66762bb 100644 (file)
--- a/arch/arc/plat-arcfpga/platform.c
+++ b/arch/arc/plat-arcfpga/platform.c
@@ -13,6 +13,7 @@
 #include <linux/device.h>
 #include <linux/platform_device.h>
 #include <linux/console.h>
+#include <linux/of_platform.h>
 #include <asm/setup.h>
 #include <asm/irq.h>
 #include <asm/clk.h>
@@ -20,58 +21,56 @@
 
 /*----------------------- Platform Devices -----------------------------*/
 
-#if defined(CONFIG_SERIAL_ARC) || defined(CONFIG_SERIAL_ARC_MODULE)
-
 static unsigned long arc_uart_info[] = {
-       CONFIG_ARC_SERIAL_BAUD, /* uart->baud */
-       -1,                     /* uart->port.uartclk */
-       -1,                     /* uart->is_emulated (runtime @running_on_hw) */
+       0,      /* uart->is_emulated (runtime @running_on_hw) */
+       0,      /* uart->port.uartclk */
+       0,      /* uart->baud */
        0
 };
 
-#define ARC_UART_DEV(n)                                        \
-                                                       \
-static struct resource arc_uart##n##_res[] = {         \
-       {                                               \
-               .start = UART##n##_BASE,                        \
-               .end   = UART##n##_BASE + 0xFF,         \
-               .flags = IORESOURCE_MEM,                \
-       },                                              \
-       {                                               \
-               .start = UART##n##_IRQ,                 \
-               .end   = UART##n##_IRQ,                 \
-               .flags = IORESOURCE_IRQ,                \
-       },                                              \
-};                                                     \
-                                                       \
-static struct platform_device arc_uart##n##_dev = {    \
-       .name = "arc-uart",                             \
-       .id = n,                                        \
-       .num_resources = ARRAY_SIZE(arc_uart##n##_res), \
-       .resource = arc_uart##n##_res,                  \
-       .dev = {                                        \
-               .platform_data = &arc_uart_info,        \
-       },                                              \
-}
+#if defined(CONFIG_SERIAL_ARC_CONSOLE)
+/*
+ * static platform data - but only for early serial
+ * TBD: derive this from a special DT node
+ */
+static struct resource arc_uart0_res[] = {
+       {
+               .start = UART0_BASE,
+               .end   = UART0_BASE + 0xFF,
+               .flags = IORESOURCE_MEM,
+       },
+       {
+               .start = UART0_IRQ,
+               .end   = UART0_IRQ,
+               .flags = IORESOURCE_IRQ,
+       },
+};
 
-ARC_UART_DEV(0);
-#if CONFIG_SERIAL_ARC_NR_PORTS > 1
-ARC_UART_DEV(1);
-#endif
+static struct platform_device arc_uart0_dev = {
+       .name = "arc-uart",
+       .id = 0,
+       .num_resources = ARRAY_SIZE(arc_uart0_res),
+       .resource = arc_uart0_res,
+       .dev = {
+               .platform_data = &arc_uart_info,
+       },
+};
 
 static struct platform_device *fpga_early_devs[] __initdata = {
-#if defined(CONFIG_SERIAL_ARC_CONSOLE)
        &arc_uart0_dev,
-#endif
 };
+#endif
 
 static void arc_fpga_serial_init(void)
 {
+       /* To let driver workaround ISS bug: baudh Reg can't be set to 0 */
+       arc_uart_info[0] = !running_on_hw;
+
        arc_uart_info[1] = arc_get_core_freq();
 
-       /* To let driver workaround ISS bug: baudh Reg can't be set to 0 */
-       arc_uart_info[2] = !running_on_hw;
+       arc_uart_info[2] = CONFIG_ARC_SERIAL_BAUD;
 
+#if defined(CONFIG_SERIAL_ARC_CONSOLE)
        early_platform_add_devices(fpga_early_devs,
                                   ARRAY_SIZE(fpga_early_devs));
 
@@ -97,16 +96,9 @@ static void arc_fpga_serial_init(void)
         * otherwise the early console never gets a chance to run.
         */
        add_preferred_console("ttyARC", 0, "115200");
+#endif
 }
 
-#else
-
-static void arc_fpga_serial_init(void)
-{
-}
-
-#endif /* CONFIG_SERIAL_ARC */
-
 /*
  * Early Platform Initialization called from setup_arch()
  */
@@ -117,20 +109,23 @@ void __init arc_platform_early_init(void)
        arc_fpga_serial_init();
 }
 
-static struct platform_device *fpga_devs[] __initdata = {
+static struct of_dev_auxdata plat_auxdata_lookup[] __initdata = {
 #if defined(CONFIG_SERIAL_ARC) || defined(CONFIG_SERIAL_ARC_MODULE)
-       &arc_uart0_dev,
-#if CONFIG_SERIAL_ARC_NR_PORTS > 1
-       &arc_uart1_dev,
-#endif
+       OF_DEV_AUXDATA("snps,arc-uart", UART0_BASE, "arc-uart", arc_uart_info),
 #endif
+       {}
 };
 
 int __init fpga_plat_init(void)
 {
        pr_info("[plat-arcfpga]: registering device resources\n");
 
-       platform_add_devices(fpga_devs, ARRAY_SIZE(fpga_devs));
+       /*
+        * Traverses flattened DeviceTree - registering platform devices
+        * complete with their resources
+        */
+       of_platform_populate(NULL, of_default_bus_match_table,
+                            plat_auxdata_lookup, NULL);
 
        return 0;
 }