ARM: vexpress: Add Device Tree support

This patch adds generic Versatile Express DT machine description,
Device Tree description for the motherboard and documentation for
the bindings.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>

4 files changed, 203 insertions, 5 deletions

diff --git a/arch/arm/mach-vexpress/Kconfig b/arch/arm/mach-vexpress/Kconfig
index 9b3d0fbaee7..cf8730d35e7 100644
--- a/arch/arm/mach-vexpress/Kconfig
+++ b/arch/arm/mach-vexpress/Kconfig
@@ -1,14 +1,55 @@
 menu "Versatile Express platform type"
 	depends on ARCH_VEXPRESS
 
+config ARCH_VEXPRESS_CORTEX_A5_A9_ERRATA
+	bool
+	select ARM_ERRATA_720789
+	select ARM_ERRATA_751472
+	select PL310_ERRATA_753970 if CACHE_PL310
+	help
+	  Provides common dependencies for Versatile Express platforms
+	  based on Cortex-A5 and Cortex-A9 processors. In order to
+	  build a working kernel, you must also enable relevant core
+	  tile support or Flattened Device Tree based support options.
+
 config ARCH_VEXPRESS_CA9X4
 	bool "Versatile Express Cortex-A9x4 tile"
+	select ARCH_VEXPRESS_CORTEX_A5_A9_ERRATA
+	select ARM_GIC
 	select CPU_V7
+	select HAVE_SMP
+	select MIGHT_HAVE_CACHE_L2X0
+
+config ARCH_VEXPRESS_DT
+	bool "Device Tree support for Versatile Express platforms"
+	select ARCH_VEXPRESS_CORTEX_A5_A9_ERRATA
 	select ARM_GIC
-	select ARM_ERRATA_720789
-	select ARM_ERRATA_751472
-	select ARM_ERRATA_753970
+	select ARM_PATCH_PHYS_VIRT
+	select AUTO_ZRELADDR
+	select CPU_V7
 	select HAVE_SMP
 	select MIGHT_HAVE_CACHE_L2X0
+	select USE_OF
+	help
+	  New Versatile Express platforms require Flattened Device Tree to
+	  be passed to the kernel.
+
+	  This option enables support for systems using Cortex processor based
+	  ARM core and logic (FPGA) tiles on the Versatile Express motherboard,
+	  for example:
+
+	  - CoreTile Express A5x2 (V2P-CA5s)
+	  - CoreTile Express A9x4 (V2P-CA9)
+	  - CoreTile Express A15x2 (V2P-CA15)
+	  - LogicTile Express 13MG (V2F-2XV6) with A5, A7, A9 or A15 SMMs
+	    (Soft Macrocell Models)
+	  - Versatile Express RTSMs (Models)
+
+	  You must boot using a Flattened Device Tree in order to use these
+	  platforms. The traditional (ATAGs) boot method is not usable on
+	  these boards with this option.
+
+	  If your bootloader supports Flattened Device Tree based booting,
+	  say Y here.
 
 endmenu
diff --git a/arch/arm/mach-vexpress/Makefile.boot b/arch/arm/mach-vexpress/Makefile.boot
index 8630b3d10a4..c6dd8918b9e 100644
--- a/arch/arm/mach-vexpress/Makefile.boot
+++ b/arch/arm/mach-vexpress/Makefile.boot
@@ -1,3 +1,5 @@
+# Those numbers are used only by the non-DT V2P-CA9 platform
+# The DT-enabled ones require CONFIG_AUTO_ZRELADDR=y
    zreladdr-y	+= 0x60008000
 params_phys-y	:= 0x60000100
 initrd_phys-y	:= 0x60800000
diff --git a/arch/arm/mach-vexpress/include/mach/motherboard.h b/arch/arm/mach-vexpress/include/mach/motherboard.h
index b4c498c1dbe..31a92890893 100644
--- a/arch/arm/mach-vexpress/include/mach/motherboard.h
+++ b/arch/arm/mach-vexpress/include/mach/motherboard.h
@@ -117,6 +117,12 @@ int v2m_cfg_read(u32 devfn, u32 *data);
 void v2m_flags_set(u32 data);
 
 /*
+ * Miscellaneous
+ */
+#define SYS_MISC_MASTERSITE	(1 << 14)
+#define SYS_PROCIDx_HBI_MASK	0xfff
+
+/*
  * Core tile IDs
  */
 #define V2M_CT_ID_CA9		0x0c000191
diff --git a/arch/arm/mach-vexpress/v2m.c b/arch/arm/mach-vexpress/v2m.c
index c76f9144898..dbf05510300 100644
--- a/arch/arm/mach-vexpress/v2m.c
+++ b/arch/arm/mach-vexpress/v2m.c
@@ -6,6 +6,10 @@
 #include <linux/amba/mmci.h>
 #include <linux/io.h>
 #include <linux/init.h>
+#include <linux/of_address.h>
+#include <linux/of_fdt.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/ata_platform.h>
 #include <linux/smsc911x.h>
@@ -21,6 +25,8 @@
 #include <asm/mach/map.h>
 #include <asm/mach/time.h>
 #include <asm/hardware/arm_timer.h>
+#include <asm/hardware/cache-l2x0.h>
+#include <asm/hardware/gic.h>
 #include <asm/hardware/timer-sp.h>
 #include <asm/hardware/sp810.h>
 #include <asm/hardware/gic.h>
@@ -430,8 +436,9 @@ static void __init v2m_populate_ct_desc(void)
 			ct_desc = ct_descs[i];
 
 	if (!ct_desc)
-		panic("vexpress: failed to populate core tile description "
-		      "for tile ID 0x%8x\n", current_tile_id);
+		panic("vexpress: this kernel does not support core tile ID 0x%08x when booting via ATAGs.\n"
+		      "You may need a device tree blob or a different kernel to boot on this board.\n",
+		      current_tile_id);
 }
 
 static void __init v2m_map_io(void)
@@ -476,3 +483,145 @@ MACHINE_START(VEXPRESS, "ARM-Versatile Express")
 	.init_machine	= v2m_init,
 	.restart	= v2m_restart,
 MACHINE_END
+
+#if defined(CONFIG_ARCH_VEXPRESS_DT)
+
+void __init v2m_dt_map_io(void)
+{
+	iotable_init(v2m_io_desc, ARRAY_SIZE(v2m_io_desc));
+
+#if defined(CONFIG_SMP)
+	vexpress_dt_smp_map_io();
+#endif
+}
+
+static struct clk_lookup v2m_dt_lookups[] = {
+	{	/* AMBA bus clock */
+		.con_id		= "apb_pclk",
+		.clk		= &dummy_apb_pclk,
+	}, {	/* SP804 timers */
+		.dev_id		= "sp804",
+		.con_id		= "v2m-timer0",
+		.clk		= &v2m_sp804_clk,
+	}, {	/* SP804 timers */
+		.dev_id		= "sp804",
+		.con_id		= "v2m-timer1",
+		.clk		= &v2m_sp804_clk,
+	}, {	/* PL180 MMCI */
+		.dev_id		= "mb:mmci", /* 10005000.mmci */
+		.clk		= &osc2_clk,
+	}, {	/* PL050 KMI0 */
+		.dev_id		= "10006000.kmi",
+		.clk		= &osc2_clk,
+	}, {	/* PL050 KMI1 */
+		.dev_id		= "10007000.kmi",
+		.clk		= &osc2_clk,
+	}, {	/* PL011 UART0 */
+		.dev_id		= "10009000.uart",
+		.clk		= &osc2_clk,
+	}, {	/* PL011 UART1 */
+		.dev_id		= "1000a000.uart",
+		.clk		= &osc2_clk,
+	}, {	/* PL011 UART2 */
+		.dev_id		= "1000b000.uart",
+		.clk		= &osc2_clk,
+	}, {	/* PL011 UART3 */
+		.dev_id		= "1000c000.uart",
+		.clk		= &osc2_clk,
+	}, {	/* SP805 WDT */
+		.dev_id		= "1000f000.wdt",
+		.clk		= &v2m_ref_clk,
+	}, {	/* PL111 CLCD */
+		.dev_id		= "1001f000.clcd",
+		.clk		= &osc1_clk,
+	},
+};
+
+void __init v2m_dt_init_early(void)
+{
+	struct device_node *node;
+	u32 dt_hbi;
+
+	node = of_find_compatible_node(NULL, NULL, "arm,vexpress-sysreg");
+	v2m_sysreg_base = of_iomap(node, 0);
+	if (WARN_ON(!v2m_sysreg_base))
+		return;
+
+	/* Confirm board type against DT property, if available */
+	if (of_property_read_u32(allnodes, "arm,hbi", &dt_hbi) == 0) {
+		u32 misc = readl(v2m_sysreg_base + V2M_SYS_MISC);
+		u32 id = readl(v2m_sysreg_base + (misc & SYS_MISC_MASTERSITE ?
+				V2M_SYS_PROCID1 : V2M_SYS_PROCID0));
+		u32 hbi = id & SYS_PROCIDx_HBI_MASK;
+
+		if (WARN_ON(dt_hbi != hbi))
+			pr_warning("vexpress: DT HBI (%x) is not matching "
+					"hardware (%x)!\n", dt_hbi, hbi);
+	}
+
+	clkdev_add_table(v2m_dt_lookups, ARRAY_SIZE(v2m_dt_lookups));
+	versatile_sched_clock_init(v2m_sysreg_base + V2M_SYS_24MHZ, 24000000);
+}
+
+static  struct of_device_id vexpress_irq_match[] __initdata = {
+	{ .compatible = "arm,cortex-a9-gic", .data = gic_of_init, },
+	{}
+};
+
+static void __init v2m_dt_init_irq(void)
+{
+	of_irq_init(vexpress_irq_match);
+}
+
+static void __init v2m_dt_timer_init(void)
+{
+	struct device_node *node;
+	const char *path;
+	int err;
+
+	node = of_find_compatible_node(NULL, NULL, "arm,sp810");
+	v2m_sysctl_init(of_iomap(node, 0));
+
+	err = of_property_read_string(of_aliases, "arm,v2m_timer", &path);
+	if (WARN_ON(err))
+		return;
+	node = of_find_node_by_path(path);
+	v2m_sp804_init(of_iomap(node, 0), irq_of_parse_and_map(node, 0));
+}
+
+static struct sys_timer v2m_dt_timer = {
+	.init = v2m_dt_timer_init,
+};
+
+static struct of_dev_auxdata v2m_dt_auxdata_lookup[] __initdata = {
+	OF_DEV_AUXDATA("arm,vexpress-flash", V2M_NOR0, "physmap-flash",
+			&v2m_flash_data),
+	OF_DEV_AUXDATA("arm,primecell", V2M_MMCI, "mb:mmci", &v2m_mmci_data),
+	{}
+};
+
+static void __init v2m_dt_init(void)
+{
+	l2x0_of_init(0x00400000, 0xfe0fffff);
+	of_platform_populate(NULL, of_default_bus_match_table,
+			v2m_dt_auxdata_lookup, NULL);
+	pm_power_off = v2m_power_off;
+}
+
+const static char *v2m_dt_match[] __initconst = {
+	"arm,vexpress",
+	NULL,
+};
+
+DT_MACHINE_START(VEXPRESS_DT, "ARM-Versatile Express")
+	.dt_compat	= v2m_dt_match,
+	.map_io		= v2m_dt_map_io,
+	.init_early	= v2m_dt_init_early,
+	.init_irq	= v2m_dt_init_irq,
+	.timer		= &v2m_dt_timer,
+	.init_machine	= v2m_dt_init,
+	.handle_irq	= gic_handle_irq,
+	.restart	= v2m_restart,
+MACHINE_END
+
+#endif