ARM: realview: basic device tree implementation

This implements basic device tree boot support for the RealView platforms, with a basic device tree for ARM PB1176 as an example.

The implementation is done with a new DT-specific board file using only pre-existing bindings for the basic IRQ, timer and serial port drivers. A new compatible type is added to the GIC for the ARM1176.

This implementation uses the MFD syscon handle from day one to access the system controller registers, and register the devices using the SoC bus.

Signed-off-by Linus Walleij <[email protected]>

Documentation/devicetree/bindings/arm/arm-boards +11 -0

+
+ARM RealView Boards
+-------------------
+The RealView boards cover tailored evaluation boards that are used to explore
+the ARM11 and Cortex A-8 and Cortex A-9 processors.
+
+Required properties (in root node):
+	/* RealView Emulation Baseboard */
+	compatible = "arm,realview-eb";
+	 /* RealView Platform Baseboard for ARM1176JZF-S */
+	compatible = "arm,realview-pb1176";

arch/arm/mach-realview/realview-dt.c new file +28 -0

+static void __init realview_dt_init_machine(void)
+{
+	struct device_node *root;
+	struct device_node *syscon;
+	struct soc_device *soc_dev;
+	struct soc_device_attribute *soc_dev_attr;
+	struct device *parent;
+	u32 coreid;
+	int ret;
+
+#ifdef CONFIG_CACHE_L2X0
+	if (of_machine_is_compatible("arm,realview-eb"))
+		/*
+		 * 1MB (128KB/way), 8-way associativity,
+		 * evmon/parity/share enabled
+		 * Bits:  .... ...0 0111 1001 0000 .... .... ....
+		 */
+		l2x0_of_init(0x00790000, 0xfe000fff);
+	else if (of_machine_is_compatible("arm,realview-pb1176"))
+		/*
+		 * 128Kb (16Kb/way) 8-way associativity.
+		 * evmon/parity/share enabled.
+		 */
+		l2x0_of_init(0x00730000, 0xfe000fff);
+	else if (of_machine_is_compatible("arm,realview-pb11mp"))
+		/*
+		 * 1MB (128KB/way), 8-way associativity,
+		 * evmon/parity/share enabled

arch/arm/mach-realview/realview-dt.c new file +33 -0

+        /* Here we create an SoC device for the root node */
+	root = of_find_node_by_path("/");
+	if (!root)
+		return;
+	syscon = of_find_matching_node(root, realview_syscon_match);
+	if (!syscon)
+		return;
+
+	soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+	if (!soc_dev_attr)
+		return;
+	ret = of_property_read_string(root, "compatible",
+				      &soc_dev_attr->soc_id);
+	if (ret)
+		return;
+	ret = of_property_read_string(root, "model", &soc_dev_attr->machine);
+        if (ret)
+		return;
+	soc_dev_attr->family = "RealView";
+	soc_dev = soc_device_register(soc_dev_attr);
+	if (IS_ERR(soc_dev)) {
+		kfree(soc_dev_attr);
+		return;
+	}
+	parent = soc_device_to_device(soc_dev);
+	ret = of_platform_populate(root, of_default_bus_match_table,
+				   NULL, parent);
+	if (ret) {
+		pr_crit("could not populate device tree\n");
+		return;
+	}
+
+	syscon_regmap = syscon_node_to_regmap(syscon);

arch/arm/mach-realview/realview-dt.c new file +5 -0

+#ifdef CONFIG_SPARSEMEM
+	/*
+	 * Memory configuration with SPARSEMEM enabled on RealView PBX (see
+	 * asm/mach/memory.h for more information).
+	 */

arch/arm/mach-realview/realview-dt.c new file +7 -0

+	/*
+	 * Generic RealView fixup
+	 * Most RealView platforms have 512MB contiguous RAM at 0x70000000.
+	 * Half of this is mirrored at 0.
+	 */
+	else {
+#ifdef CONFIG_REALVIEW_HIGH_PHYS_OFFSET

arch/arm/mach-realview/realview-dt.c new file +19 -0

+static void realview_dt_restart(enum reboot_mode mode, const char *cmd)
+{
+	if (IS_ERR(syscon_regmap))
+		return;
+
+	/* Unlock the reset register */
+	regmap_write(syscon_regmap, REALVIEW_SYS_LOCK_OFFSET,
+		     REALVIEW_SYS_LOCK_VAL);
+	/* Then hit reset on the different machines */
+	if (of_machine_is_compatible("arm,realview-eb")) {
+		regmap_write(syscon_regmap,
+			     REALVIEW_SYS_RESETCTL_OFFSET, 0x0008);
+	} else if (of_machine_is_compatible("arm,realview-pb1176")) {
+		regmap_write(syscon_regmap,
+			     REALVIEW_SYS_RESETCTL_OFFSET, 0x0100);
+	} else if (of_machine_is_compatible("arm,realview-pb11mp") ||
+		   of_machine_is_compatible("arm,realview-pba8")) {
+		regmap_write(syscon_regmap, REALVIEW_SYS_RESETCTL_OFFSET,
+			     0x0000);

Quoted 15 lines

(quoted diff) +15 -0

+     /*
+      * Generic RealView fixup
+      * Most RealView platforms have 512MB contiguous RAM at 0x70000000.
+      * Half of this is mirrored at 0.
+      */
+     else {
+#ifdef CONFIG_REALVIEW_HIGH_PHYS_OFFSET
+             meminfo->bank[0].start = 0x70000000;
+             meminfo->bank[0].size = SZ_512M;
+             meminfo->nr_banks = 1;
+#else
+             meminfo->bank[0].start = 0;
+             meminfo->bank[0].size = SZ_256M;
+             meminfo->nr_banks = 1;
+#endif

Review

Quoted 2 lines

(quoted diff) +2 -0

+     }
+}

And this one is where it gets tricky. We don't have a good way to describe memory aliases in DT, but we need the start of memory to match PHYS_OFFSET if CONFIG_SPARSEMEM is set (which implies !CONFIG_REALVIEW_HIGH_PHYS_OFFSET), or if we are running a no-MMU kernel. I have to think about this some more.

I don't know if the ATAGS are actually correct in common boot loaders, since the kernel has been overriding them for ages.

Catalin originally added the sparsemem hack. I asked him today about it, and he also thinks that sparsemem without the hack should work, as long as there is highmem support. I think we can either do away with it entirely, or use the patch below to keep it alive.

Quoted 4 lines · Arnd Bergmann

Catalin originally added the sparsemem hack. I asked him today about it, and he also thinks that sparsemem without the hack should work, as long as there is highmem support. I think we can either do away with it entirely, or use the patch below to keep it alive.

IMO the patch make things worse. I'd just say we switch it to use highmem and get rid of the madness.

Anyone claiming to be running performance-critical loads on the PBX is either insane or a liar.

arch/arm/boot/dts/arm-realview-pb1176.dts line 117

Quoted 8 lines

arch/arm/boot/dts/arm-realview-pb1176.dts new file +8 -0

+             timer01: timer at 10104000 {
+                     compatible = "arm,sp804", "arm,primecell";
+                     reg = <0x10104000 0x1000>;
+                     interrupt-parent = <&intc_dc1176>;
+                     interrupts = <0 8 IRQ_TYPE_LEVEL_HIGH>, <0 9 IRQ_TYPE_LEVEL_HIGH>;
+                     clocks = <&timclk>, <&timclk>, <&pclk>;
+                     clock-names = "timclk1", "timclk2", "apb_pclk";
+             };

In the binding, the clock names are "timer1", "timer2", "apb_pclk". What is going on here?

arch/arm/boot/dts/arm-realview-pb1176.dts line 163

Quoted 9 lines

arch/arm/boot/dts/arm-realview-pb1176.dts new file +9 -0

+
+             pb1176_serial3: uart at 1010f000 {
+                     compatible = "arm,pl011", "arm,primecell";
+                     reg = <0x1010f000 0x1000>;
+                     interrupt-parent = <&intc_dc1176>;
+                     interrupts = <0 21 IRQ_TYPE_LEVEL_HIGH>;
+                     clocks = <&uartclk>, <&pclk>;
+                     clock-names = "uartclk", "apb_pclk";
+             };

Here, the binding says:

- clocks: When present, must refer to exactly one clock named

           "apb_pclk"

Quoted 34 lines

arch/arm/mach-realview/realview-dt.c new file +34 -0

+static void __init realview_dt_init_machine(void)
+{
+     struct device_node *root;
+     struct device_node *syscon;
+     struct soc_device *soc_dev;
+     struct soc_device_attribute *soc_dev_attr;
+     struct device *parent;
+     u32 coreid;
+     int ret;
+
+#ifdef CONFIG_CACHE_L2X0
+     if (of_machine_is_compatible("arm,realview-eb"))
+             /*
+              * 1MB (128KB/way), 8-way associativity,
+              * evmon/parity/share enabled
+              * Bits:  .... ...0 0111 1001 0000 .... .... ....
+              */
+             l2x0_of_init(0x00790000, 0xfe000fff);
+     else if (of_machine_is_compatible("arm,realview-pb1176"))
+             /*
+              * 128Kb (16Kb/way) 8-way associativity.
+              * evmon/parity/share enabled.
+              */
+             l2x0_of_init(0x00730000, 0xfe000fff);
+     else if (of_machine_is_compatible("arm,realview-pb11mp"))
+             /*
+              * 1MB (128KB/way), 8-way associativity,
+              * evmon/parity/share enabled
+              * Bits:  .... ...0 0111 1001 0000 .... .... ....
+              */
+             l2x0_of_init(0x00730000, 0xfe000fff);
+     else if (of_machine_is_compatible("arm,realview-pbx"))
+             /*
+              * 16KB way size, 8-way associativity, parity disabled

arch/arm/mach-realview/realview-dt.c line 93

Quoted 4 lines

arch/arm/mach-realview/realview-dt.c new file +4 -0

+              * Bits:  .. 0 0 0 0 1 00 1 0 1 001 0 000 0 .... .... ....
+              */
+             l2x0_of_init(0x02520000, 0xc0000fff);
+#endif

Russell just posted a long series of l2x0 cleanup patches. One of the things coming out of that was that we should never need to pass values like this here.

The registers are typically initialized
to a hardwired default that should be ok, and if not, the boot loader should set them up correctly. Can you print out the boot-time values to see if realview gets this wrong?

Quoted 40 lines

arch/arm/mach-realview/realview-dt.c new file +40 -0

+        /* Here we create an SoC device for the root node */
+     root = of_find_node_by_path("/");
+     if (!root)
+             return;
+     syscon = of_find_matching_node(root, realview_syscon_match);
+     if (!syscon)
+             return;
+
+     soc_dev_attr = kzalloc(sizeof(*soc_dev_attr), GFP_KERNEL);
+     if (!soc_dev_attr)
+             return;
+     ret = of_property_read_string(root, "compatible",
+                                   &soc_dev_attr->soc_id);
+     if (ret)
+             return;
+     ret = of_property_read_string(root, "model", &soc_dev_attr->machine);
+        if (ret)
+             return;
+     soc_dev_attr->family = "RealView";
+     soc_dev = soc_device_register(soc_dev_attr);
+     if (IS_ERR(soc_dev)) {
+             kfree(soc_dev_attr);
+             return;
+     }
+     parent = soc_device_to_device(soc_dev);
+     ret = of_platform_populate(root, of_default_bus_match_table,
+                                NULL, parent);
+     if (ret) {
+             pr_crit("could not populate device tree\n");
+             return;
+     }
+
+     syscon_regmap = syscon_node_to_regmap(syscon);
+     if (IS_ERR(syscon_regmap)) {
+             pr_crit("could not locate syscon regmap\n");
+             return;
+     }
+     ret = regmap_read(syscon_regmap, REALVIEW_SYS_ID_OFFSET, &coreid);
+     if (ret)
+             return;

arch/arm/mach-realview/realview-dt.c line 137

Quoted 3 lines

arch/arm/mach-realview/realview-dt.c new file +3 -0

+     pr_info("RealView Syscon Core ID: 0x%08x\n", coreid);
+     /* FIXME: add attributes for SoC to sysfs */
+}

I would not register a "soc" device for the root node, but rather reorganize the DT to put all soc specific nodes under a combined soc node. I suppose that could actually be the syscon node itself.

Quoted 5 lines

arch/arm/mach-realview/realview-dt.c new file +5 -0

+static void realview_dt_fixup(struct tag *tags, char **from,
+                             struct meminfo *meminfo)
+{
+     /*
+      * RealView PB1176 only has 128MB of RAM mapped at 0.

arch/arm/mach-realview/realview-dt.c line 149

Quoted 6 lines

arch/arm/mach-realview/realview-dt.c new file +6 -0

+      */
+     if (of_machine_is_compatible("arm,realview-pb1176")) {
+             meminfo->bank[0].start = 0;
+             meminfo->bank[0].size = SZ_128M;
+             meminfo->nr_banks = 1;
+     }

This one should come right from DT I think.

Quoted 10 lines

arch/arm/mach-realview/realview-dt.c new file +10 -0

+#ifdef CONFIG_SPARSEMEM
+     /*
+      * Memory configuration with SPARSEMEM enabled on RealView PBX (see
+      * asm/mach/memory.h for more information).
+      */
+     else if (of_machine_is_compatible("arm,realview-pbx")) {
+             meminfo->bank[0].start = 0;
+             meminfo->bank[0].size = SZ_256M;
+             meminfo->bank[1].start = 0x20000000;
+             meminfo->bank[1].size = SZ_512M;

arch/arm/mach-realview/realview-dt.c line 164

Quoted 5 lines

arch/arm/mach-realview/realview-dt.c new file +5 -0

+             meminfo->bank[2].start = 0x80000000;
+             meminfo->bank[2].size = SZ_256M;
+             meminfo->nr_banks = 3;
+     }
+#endif

This one too, but I'm not completely sure about it. Do you see a reason for the kernel to override the memory location on PBX?

Quoted 15 lines

arch/arm/mach-realview/realview-dt.c new file +15 -0

+     /*
+      * Generic RealView fixup
+      * Most RealView platforms have 512MB contiguous RAM at 0x70000000.
+      * Half of this is mirrored at 0.
+      */
+     else {
+#ifdef CONFIG_REALVIEW_HIGH_PHYS_OFFSET
+             meminfo->bank[0].start = 0x70000000;
+             meminfo->bank[0].size = SZ_512M;
+             meminfo->nr_banks = 1;
+#else
+             meminfo->bank[0].start = 0;
+             meminfo->bank[0].size = SZ_256M;
+             meminfo->nr_banks = 1;
+#endif

Review

Quoted 2 lines

(quoted diff) +2 -0

+     }
+}

And this one is where it gets tricky. We don't have a good way to describe memory aliases in DT, but we need the start of memory to match PHYS_OFFSET if CONFIG_SPARSEMEM is set (which implies !CONFIG_REALVIEW_HIGH_PHYS_OFFSET), or if we are running a no-MMU kernel. I have to think about this some more.

Quoted 27 lines

arch/arm/mach-realview/realview-dt.c new file +27 -0

+static void realview_dt_restart(enum reboot_mode mode, const char *cmd)
+{
+     if (IS_ERR(syscon_regmap))
+             return;
+
+     /* Unlock the reset register */
+     regmap_write(syscon_regmap, REALVIEW_SYS_LOCK_OFFSET,
+                  REALVIEW_SYS_LOCK_VAL);
+     /* Then hit reset on the different machines */
+     if (of_machine_is_compatible("arm,realview-eb")) {
+             regmap_write(syscon_regmap,
+                          REALVIEW_SYS_RESETCTL_OFFSET, 0x0008);
+     } else if (of_machine_is_compatible("arm,realview-pb1176")) {
+             regmap_write(syscon_regmap,
+                          REALVIEW_SYS_RESETCTL_OFFSET, 0x0100);
+     } else if (of_machine_is_compatible("arm,realview-pb11mp") ||
+                of_machine_is_compatible("arm,realview-pba8")) {
+             regmap_write(syscon_regmap, REALVIEW_SYS_RESETCTL_OFFSET,
+                          0x0000);
+             regmap_write(syscon_regmap, REALVIEW_SYS_RESETCTL_OFFSET,
+                          0x0004);
+     } else if (of_machine_is_compatible("arm,realview-pbx")) {
+             regmap_write(syscon_regmap, REALVIEW_SYS_RESETCTL_OFFSET,
+                          0x00f0);
+             regmap_write(syscon_regmap, REALVIEW_SYS_RESETCTL_OFFSET,
+                          0x00f4);
+     }

arch/arm/mach-realview/realview-dt.c line 211

Quoted 2 lines

arch/arm/mach-realview/realview-dt.c new file +2 -0

+     dsb();
+}

I'd be much happier if we had a separate device node to match against, rather than using of_machine_is_compatible(). That would allow us to later move this code out into a separate driver. Note that I'd still hope to one day have an empty directory for all the ARM reference platforms.

Quoted 4 lines

arch/arm/mach-realview/realview-dt.c new file +4 -0

+DT_MACHINE_START(REALVIEW_DT, "ARM RealView Machine (Device Tree Support)")
+     .fixup          = realview_dt_fixup,
+     .map_io         = realview_dt_map_io,
+     .init_machine   = realview_dt_init_machine,

arch/arm/mach-realview/realview-dt.c line 230

Quoted 5 lines

arch/arm/mach-realview/realview-dt.c new file +5 -0

+#ifdef CONFIG_ZONE_DMA
+     .dma_zone_size  = SZ_256M,
+#endif
+     .dt_compat      = realview_dt_platform_compat,
+     .restart        = realview_dt_restart,

This isn't specific to the DT version of realview, but what happens if CONFIG_ZONE_DMA is disabled?

This implements basic device tree boot support for the RealView platforms, with a basic device tree for ARM PB1176 as an example.

The implementation is done with a new DT-specific board file using only pre-existing bindings for the basic IRQ, timer and serial port drivers. A new compatible type is added to the GIC for the ARM1176.

This implementation uses the MFD syscon handle from day one to access the system controller registers, and register the devices using the SoC bus.

Signed-off-by Linus Walleij <[email protected]>

---
 Documentation/devicetree/bindings/arm/arm-boards |  53 ++++++
 arch/arm/boot/dts/Makefile                       |   1 +
 arch/arm/boot/dts/arm-realview-pb1176.dts        | 165 ++++++++++++++++
 arch/arm/mach-realview/Kconfig                   |  10 +
 arch/arm/mach-realview/Makefile                  |   1 +
 arch/arm/mach-realview/realview-dt.c             | 231 +++++++++++++++++++++++
 arch/arm/mm/Kconfig                              |   2 +-
 drivers/irqchip/irq-gic.c                        |   1 +
 8 files changed, 463 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm/boot/dts/arm-realview-pb1176.dts
 create mode 100644 arch/arm/mach-realview/realview-dt.c

Documentation/devicetree/bindings/arm/arm-boards +12 -0

index 3509707f9320..22af7ccacb52 100644
@@ -86,3 +86,56 @@ Interrupt controllers:
        compatible = "arm,versatile-sic";
        interrupt-controller;
        #interrupt-cells = <1>;
+
+
+ARM RealView Boards
+-------------------
+The RealView boards cover tailored evaluation boards that are used to explore
+the ARM11 and Cortex A-8 and Cortex A-9 processors.
+
+Required properties (in root node):
+       /* RealView Emulation Baseboard */
+       compatible = "arm,realview-eb";
+        /* RealView Platform Baseboard for ARM1176JZF-S */
+       compatible = "arm,realview-pb1176";

Documentation/devicetree/bindings/arm/arm-boards +28 -0

+
+  Required properties for the system controller:
+  - regs: the location and size of the system controller registers,
+    one range of 0x1000 bytes.
+
+Example:
+
+/dts-v1/;
+#include <dt-bindings/interrupt-controller/irq.h>
+#include "skeleton.dtsi"
+
+/ {
+       model = "ARM RealView PB1176 with device tree";
+       compatible = "arm,realview-pb1176";
+
+       soc {
+               #address-cells = <1>;
+               #size-cells = <1>;
+               compatible = "simple-bus";
+               ranges;
+
+               syscon: syscon at 10000000 {
+                       compatible = "arm,realview-syscon", "syscon";
+                       reg = <0x10000000 0x1000>;
+               };
+
+       };
+};

arch/arm/boot/dts/Makefile +1 -0

index 032030361bef..f568746abf91 100644
@@ -234,6 +234,7 @@ dtb-$(CONFIG_ARCH_OMAP2PLUS) += omap2420-h4.dtb \
        dra7-evm.dtb
 dtb-$(CONFIG_ARCH_ORION5X) += orion5x-lacie-ethernet-disk-mini-v2.dtb
 dtb-$(CONFIG_ARCH_PRIMA2) += prima2-evb.dtb
+dtb-$(CONFIG_ARCH_REALVIEW) += arm-realview-pb1176.dtb
 dtb-$(CONFIG_ARCH_U8500) += ste-snowball.dtb \
        ste-hrefprev60-stuib.dtb \
        ste-hrefprev60-tvk.dtb \

arch/arm/boot/dts/arm-realview-pb1176.dts new file +0 -0

new file mode 100644
index 000000000000..3703fca68513

arch/arm/boot/dts/arm-realview-pb1176.dts new file +55 -0

+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+/dts-v1/;
+#include <dt-bindings/interrupt-controller/irq.h>
+#include "skeleton.dtsi"
+
+/ {
+       model = "ARM RealView PB1176 with device tree";
+       compatible = "arm,realview-pb1176";
+
+       chosen { };
+
+       aliases {
+               serial0 = &pb1176_serial0;
+               serial1 = &pb1176_serial1;
+               serial2 = &pb1176_serial2;
+               serial3 = &pb1176_serial3;
+       };
+
+       memory {
+               reg = <0x00000000 0x08000000>;
+       };
+
+       soc {
+               #address-cells = <1>;
+               #size-cells = <1>;
+               compatible = "simple-bus";
+               ranges;
+
+               syscon: syscon at 10000000 {
+                       compatible = "arm,realview-syscon", "syscon";
+                       reg = <0x10000000 0x1000>;
+               };
+
+               xtal24mhz: xtal24mhz at 24M {
+                       #clock-cells = <0>;
+                       compatible = "fixed-clock";
+                       clock-frequency = <24000000>;
+               };
+
+               timclk: timclk at 1M {
+                       #clock-cells = <0>;
+                       compatible = "fixed-factor-clock";
+                       clock-div = <24>;
+                       clock-mult = <1>;
+                       clocks = <&xtal24mhz>;
+               };
+
+               uartclk: uartclk at 24M {
+                       #clock-cells = <0>;
+                       compatible = "fixed-factor-clock";
+                       clock-div = <1>;

arch/arm/boot/dts/arm-realview-pb1176.dts new file +90 -0

+                       #interrupt-cells = <3>;
+                       #address-cells = <1>;
+                       interrupt-controller;
+                       reg = <0x10121000 0x1000>,
+                             <0x10120000 0x100>;
+               };
+
+               /* This GIC on the board is cascaded off the DevChip GIC */
+               intc_pb1176: interrupt-controller at 10040000 {
+                       compatible = "arm,arm1176jzf-gic";
+                       #interrupt-cells = <3>;
+                       #address-cells = <1>;
+                       interrupt-controller;
+                       reg = <0x10041000 0x1000>,
+                             <0x10040000 0x100>;
+                       interrupt-parent = <&intc_dc1176>;
+                       interrupts = <0 31 IRQ_TYPE_LEVEL_HIGH>;
+               };
+
+               L2: l2-cache {
+                       compatible = "arm,l220-cache";
+                       reg = <0x10110000 0x1000>;
+                       interrupt-parent = <&intc_dc1176>;
+                       interrupts = <0 13 IRQ_TYPE_LEVEL_HIGH>;
+                       cache-unified;
+                       cache-level = <2>;
+               };
+
+               pmu {
+                       compatible = "arm,arm1176-pmu";
+                       interrupt-parent = <&intc_dc1176>;
+                       interrupts = <0 7 IRQ_TYPE_LEVEL_HIGH>;
+               };
+
+               timer01: timer at 10104000 {
+                       compatible = "arm,sp804", "arm,primecell";
+                       reg = <0x10104000 0x1000>;
+                       interrupt-parent = <&intc_dc1176>;
+                       interrupts = <0 8 IRQ_TYPE_LEVEL_HIGH>, <0 9 IRQ_TYPE_LEVEL_HIGH>;
+                       clocks = <&timclk>, <&timclk>, <&pclk>;
+                       clock-names = "timclk1", "timclk2", "apb_pclk";
+               };
+
+               timer23: timer at 10105000 {
+                       compatible = "arm,sp804", "arm,primecell";
+                       reg = <0x10105000 0x1000>;
+                       interrupt-parent = <&intc_dc1176>;
+                       interrupts = <0 10 IRQ_TYPE_LEVEL_HIGH>;
+                       arm,sp804-has-irq = <1>;
+                       clocks = <&timclk>, <&timclk>, <&pclk>;
+                       clock-names = "timclk1", "timclk2", "apb_pclk";
+               };
+
+               pb1176_serial0: uart at 1010c000 {
+                       compatible = "arm,pl011", "arm,primecell";
+                       reg = <0x1010c000 0x1000>;
+                       interrupt-parent = <&intc_dc1176>;
+                       interrupts = <0 18 IRQ_TYPE_LEVEL_HIGH>;
+                       clocks = <&uartclk>, <&pclk>;
+                       clock-names = "uartclk", "apb_pclk";
+               };
+
+               pb1176_serial1: uart at 1010d000 {
+                       compatible = "arm,pl011", "arm,primecell";
+                       reg = <0x1010d000 0x1000>;
+                       interrupt-parent = <&intc_dc1176>;
+                       interrupts = <0 19 IRQ_TYPE_LEVEL_HIGH>;
+                       clocks = <&uartclk>, <&pclk>;
+                       clock-names = "uartclk", "apb_pclk";
+               };
+
+               pb1176_serial2: uart at 1010e000 {
+                       compatible = "arm,pl011", "arm,primecell";
+                       reg = <0x1010e000 0x1000>;
+                       interrupt-parent = <&intc_dc1176>;
+                       interrupts = <0 20 IRQ_TYPE_LEVEL_HIGH>;
+                       clocks = <&uartclk>, <&pclk>;
+                       clock-names = "uartclk", "apb_pclk";
+               };
+
+               pb1176_serial3: uart at 1010f000 {
+                       compatible = "arm,pl011", "arm,primecell";
+                       reg = <0x1010f000 0x1000>;
+                       interrupt-parent = <&intc_dc1176>;
+                       interrupts = <0 21 IRQ_TYPE_LEVEL_HIGH>;
+                       clocks = <&uartclk>, <&pclk>;
+                       clock-names = "uartclk", "apb_pclk";
+               };
+       };
+};

arch/arm/mach-realview/Kconfig +0 -0

index 9db2029aa632..2d29649615c7 100644

arch/arm/mach-realview/Kconfig +4 -0

+       help
+         Include support for booting the ARM(R) RealView(R) evaluation
+         boards using a device tree machine description.
+
 config MACH_REALVIEW_EB
        bool "Support RealView(R) Emulation Baseboard"
        select ARM_GIC

arch/arm/mach-realview/Makefile +1 -0

index 541fa4c109ef..e07fdf7ae8a7 100644
@@ -3,6 +3,7 @@
 #
 
 obj-y                                  := core.o
+obj-$(CONFIG_REALVIEW_DT)              += realview-dt.o
 obj-$(CONFIG_MACH_REALVIEW_EB)         += realview_eb.o
 obj-$(CONFIG_MACH_REALVIEW_PB11MP)     += realview_pb11mp.o
 obj-$(CONFIG_MACH_REALVIEW_PB1176)     += realview_pb1176.o

arch/arm/mach-realview/realview-dt.c new file +56 -0

new file mode 100644
index 000000000000..1b6f4703922c
@@ -0,0 +1,231 @@
+/*
+ * Copyright (C) 2014 Linaro Ltd.
+ *
+ * Author: Linus Walleij <[email protected]>
+ *
+ * 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.
+ *
+ */
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/arm-gic.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/sys_soc.h>
+#include <linux/slab.h>
+#include <asm/mach/map.h>
+#include <asm/mach/arch.h>
+#include <asm/hardware/cache-l2x0.h>
+#include <mach/hardware.h>
+#include <mach/platform.h>
+#include <mach/board-eb.h>
+#include <mach/board-pb1176.h>
+#include <mach/board-pb11mp.h>
+#include <mach/board-pbx.h>
+#include "core.h"
+
+/* Pointer to the system controller */
+struct regmap *syscon_regmap;
+
+static struct map_desc realview_dt_io_desc[] __initdata = {
+       {
+               /* FIXME: static map needed for LED driver */
+               .virtual        = IO_ADDRESS(REALVIEW_SYS_BASE),
+               .pfn            = __phys_to_pfn(REALVIEW_SYS_BASE),
+               .length         = SZ_4K,
+               .type           = MT_DEVICE,
+       },
+};
+
+static void __init realview_dt_map_io(void)
+{
+       iotable_init(realview_dt_io_desc, ARRAY_SIZE(realview_dt_io_desc));
+}
+
+static const struct of_device_id realview_syscon_match[] = {
+       { .compatible = "arm,realview-syscon"},
+       { },
+};
+
+static void __init realview_dt_init_machine(void)

arch/arm/mach-realview/realview-dt.c new file +17 -0

+       if (of_machine_is_compatible("arm,realview-eb"))
+               /*
+                * 1MB (128KB/way), 8-way associativity,
+                * evmon/parity/share enabled
+                * Bits:  .... ...0 0111 1001 0000 .... .... ....
+                */
+               l2x0_of_init(0x00790000, 0xfe000fff);
+       else if (of_machine_is_compatible("arm,realview-pb1176"))
+               /*
+                * 128Kb (16Kb/way) 8-way associativity.
+                * evmon/parity/share enabled.
+                */
+               l2x0_of_init(0x00730000, 0xfe000fff);
+       else if (of_machine_is_compatible("arm,realview-pb11mp"))
+               /*
+                * 1MB (128KB/way), 8-way associativity,
+                * evmon/parity/share enabled

arch/arm/mach-realview/Kconfig line 9

Quoted 9 lines · Linus Walleij

menu "RealView platform type"
depends on ARCH_REALVIEW

arch/arm/mach-realview/Kconfig +6 -0

+config REALVIEW_DT
+       bool "Support RealView(R) Device Tree based boot"
+       select ARM_GIC
+       select USE_OF
+       select SOC_BUS
+       select MFD_SYSCON

Sort.

This will probably need to be coordinated with Arnd's cpu selection rework.

Quoted 17 lines · Linus Walleij

arch/arm/mach-realview/realview-dt.c new file +17 -0

+       if (of_machine_is_compatible("arm,realview-eb"))
+               /*
+                * 1MB (128KB/way), 8-way associativity,
+                * evmon/parity/share enabled
+                * Bits:  .... ...0 0111 1001 0000 .... .... ....
+                */
+               l2x0_of_init(0x00790000, 0xfe000fff);
+       else if (of_machine_is_compatible("arm,realview-pb1176"))
+               /*
+                * 128Kb (16Kb/way) 8-way associativity.
+                * evmon/parity/share enabled.
+                */
+               l2x0_of_init(0x00730000, 0xfe000fff);
+       else if (of_machine_is_compatible("arm,realview-pb11mp"))
+               /*
+                * 1MB (128KB/way), 8-way associativity,
+                * evmon/parity/share enabled

arch/arm/mach-realview/realview-dt.c line 93

Quoted 10 lines

arch/arm/mach-realview/realview-dt.c new file +10 -0

+                * Bits:  .... ...0 0111 1001 0000 .... .... ....
+                */
+               l2x0_of_init(0x00730000, 0xfe000fff);
+       else if (of_machine_is_compatible("arm,realview-pbx"))
+               /*
+                * 16KB way size, 8-way associativity, parity disabled
+                * Bits:  .. 0 0 0 0 1 00 1 0 1 001 0 000 0 .... .... ....
+                */
+               l2x0_of_init(0x02520000, 0xc0000fff);
+#endif

As Arnd pointed out, see Russell's recent L2x0 emails. Since these are L220s, you do need the way size and associativity to be initialized at least. There are standard ePAPR definitions for these which should be used.

Documenting the initial and final aux ctrl values on these platforms would be helpful for Russell's clean-up.