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authorPaul Burton <paul.burton@imgtec.com>2016-10-05 20:18:20 +0300
committerRalf Baechle <ralf@linux-mips.org>2016-10-06 19:04:04 +0300
commiteed0eabd12ef061821cbfa20d903476e07645320 (patch)
treedabf064a54995ba234fba3bd03d19f5dd07058c4 /arch/mips/generic
parentcf2a5e0bb4c66e8c43caf9f1be93a1bd7fd07b17 (diff)
downloadlinux-eed0eabd12ef061821cbfa20d903476e07645320.tar.xz
MIPS: generic: Introduce generic DT-based board support
Introduce a "generic" platform, which aims to be board-agnostic by making use of device trees passed by the boot protocol defined in the MIPS UHI (Universal Hosting Interface) specification. Provision is made for supporting boards which use a legacy boot protocol that can't be changed, but adding support for such boards or any others is left to followon patches. Right now the built kernels expect to be loaded to 0x80100000, ie. in kseg0. This is fine for the vast majority of MIPS platforms, but nevertheless it would be good to remove this limitation in the future by mapping the kernel via the TLB such that it can be loaded anywhere & map itself appropriately. Configuration is handled by dynamically generating configs using scripts/kconfig/merge_config.sh, somewhat similar to the way powerpc makes use of it. This allows for variations upon the configuration, eg. differing architecture revisions or subsets of driver support for differing boards, to be handled without having a large number of defconfig files. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14353/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/generic')
-rw-r--r--arch/mips/generic/Kconfig12
-rw-r--r--arch/mips/generic/Makefile13
-rw-r--r--arch/mips/generic/Platform14
-rw-r--r--arch/mips/generic/init.c176
-rw-r--r--arch/mips/generic/irq.c64
-rw-r--r--arch/mips/generic/proc.c29
-rw-r--r--arch/mips/generic/vmlinux.its.S31
7 files changed, 339 insertions, 0 deletions
diff --git a/arch/mips/generic/Kconfig b/arch/mips/generic/Kconfig
new file mode 100644
index 000000000000..baddb0646b23
--- /dev/null
+++ b/arch/mips/generic/Kconfig
@@ -0,0 +1,12 @@
+if MIPS_GENERIC
+
+config LEGACY_BOARDS
+ bool
+ help
+ Select this from your board if the board must use a legacy, non-UHI,
+ boot protocol. This will cause the kernel to scan through the list of
+ supported machines calling their detect functions in turn if the
+ kernel is booted without being provided with an FDT via the UHI
+ boot protocol.
+
+endif
diff --git a/arch/mips/generic/Makefile b/arch/mips/generic/Makefile
new file mode 100644
index 000000000000..26e64207f7ad
--- /dev/null
+++ b/arch/mips/generic/Makefile
@@ -0,0 +1,13 @@
+#
+# Copyright (C) 2016 Imagination Technologies
+# Author: Paul Burton <paul.burton@imgtec.com>
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation; either version 2 of the License, or (at your
+# option) any later version.
+#
+
+obj-y += init.o
+obj-y += irq.o
+obj-y += proc.o
diff --git a/arch/mips/generic/Platform b/arch/mips/generic/Platform
new file mode 100644
index 000000000000..9a30d69e2281
--- /dev/null
+++ b/arch/mips/generic/Platform
@@ -0,0 +1,14 @@
+#
+# Copyright (C) 2016 Imagination Technologies
+# Author: Paul Burton <paul.burton@imgtec.com>
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation; either version 2 of the License, or (at your
+# option) any later version.
+#
+
+platform-$(CONFIG_MIPS_GENERIC) += generic/
+cflags-$(CONFIG_MIPS_GENERIC) += -I$(srctree)/arch/mips/include/asm/mach-generic
+load-$(CONFIG_MIPS_GENERIC) += 0xffffffff80100000
+all-$(CONFIG_MIPS_GENERIC) := vmlinux.gz.itb
diff --git a/arch/mips/generic/init.c b/arch/mips/generic/init.c
new file mode 100644
index 000000000000..0ea73e845440
--- /dev/null
+++ b/arch/mips/generic/init.c
@@ -0,0 +1,176 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ * Author: Paul Burton <paul.burton@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/clocksource.h>
+#include <linux/init.h>
+#include <linux/irqchip.h>
+#include <linux/of_fdt.h>
+#include <linux/of_platform.h>
+
+#include <asm/fw/fw.h>
+#include <asm/irq_cpu.h>
+#include <asm/machine.h>
+#include <asm/mips-cpc.h>
+#include <asm/prom.h>
+#include <asm/smp-ops.h>
+#include <asm/time.h>
+
+static __initdata const void *fdt;
+static __initdata const struct mips_machine *mach;
+static __initdata const void *mach_match_data;
+
+void __init prom_init(void)
+{
+ const struct mips_machine *check_mach;
+ const struct of_device_id *match;
+
+ if ((fw_arg0 == -2) && !fdt_check_header((void *)fw_arg1)) {
+ /*
+ * We booted using the UHI boot protocol, so we have been
+ * provided with the appropriate device tree for the board.
+ * Make use of it & search for any machine struct based upon
+ * the root compatible string.
+ */
+ fdt = (void *)fw_arg1;
+
+ for_each_mips_machine(check_mach) {
+ match = mips_machine_is_compatible(check_mach, fdt);
+ if (match) {
+ mach = check_mach;
+ mach_match_data = match->data;
+ break;
+ }
+ }
+ } else if (IS_ENABLED(CONFIG_LEGACY_BOARDS)) {
+ /*
+ * We weren't booted using the UHI boot protocol, but do
+ * support some number of boards with legacy boot protocols.
+ * Attempt to find the right one.
+ */
+ for_each_mips_machine(check_mach) {
+ if (!check_mach->detect)
+ continue;
+
+ if (!check_mach->detect())
+ continue;
+
+ mach = check_mach;
+ }
+
+ /*
+ * If we don't recognise the machine then we can't continue, so
+ * die here.
+ */
+ BUG_ON(!mach);
+
+ /* Retrieve the machine's FDT */
+ fdt = mach->fdt;
+ }
+
+ BUG_ON(!fdt);
+}
+
+void __init *plat_get_fdt(void)
+{
+ return (void *)fdt;
+}
+
+void __init plat_mem_setup(void)
+{
+ if (mach && mach->fixup_fdt)
+ fdt = mach->fixup_fdt(fdt, mach_match_data);
+
+ strlcpy(arcs_cmdline, boot_command_line, COMMAND_LINE_SIZE);
+ __dt_setup_arch((void *)fdt);
+}
+
+void __init device_tree_init(void)
+{
+ int err;
+
+ unflatten_and_copy_device_tree();
+ mips_cpc_probe();
+
+ err = register_cps_smp_ops();
+ if (err)
+ err = register_up_smp_ops();
+}
+
+void __init plat_time_init(void)
+{
+ struct device_node *np;
+ struct clk *clk;
+
+ of_clk_init(NULL);
+
+ if (!cpu_has_counter) {
+ mips_hpt_frequency = 0;
+ } else if (mach && mach->measure_hpt_freq) {
+ mips_hpt_frequency = mach->measure_hpt_freq();
+ } else {
+ np = of_get_cpu_node(0, NULL);
+ if (!np) {
+ pr_err("Failed to get CPU node\n");
+ return;
+ }
+
+ clk = of_clk_get(np, 0);
+ if (IS_ERR(clk)) {
+ pr_err("Failed to get CPU clock: %ld\n", PTR_ERR(clk));
+ return;
+ }
+
+ mips_hpt_frequency = clk_get_rate(clk);
+ clk_put(clk);
+
+ switch (boot_cpu_type()) {
+ case CPU_20KC:
+ case CPU_25KF:
+ /* The counter runs at the CPU clock rate */
+ break;
+ default:
+ /* The counter runs at half the CPU clock rate */
+ mips_hpt_frequency /= 2;
+ break;
+ }
+ }
+
+ clocksource_probe();
+}
+
+void __init arch_init_irq(void)
+{
+ struct device_node *intc_node;
+
+ intc_node = of_find_compatible_node(NULL, NULL,
+ "mti,cpu-interrupt-controller");
+ if (!cpu_has_veic && !intc_node)
+ mips_cpu_irq_init();
+
+ irqchip_init();
+}
+
+static int __init publish_devices(void)
+{
+ if (!of_have_populated_dt())
+ panic("Device-tree not present");
+
+ if (of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL))
+ panic("Failed to populate DT");
+
+ return 0;
+}
+arch_initcall(publish_devices);
+
+void __init prom_free_prom_memory(void)
+{
+}
diff --git a/arch/mips/generic/irq.c b/arch/mips/generic/irq.c
new file mode 100644
index 000000000000..14064bdd91dd
--- /dev/null
+++ b/arch/mips/generic/irq.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ * Author: Paul Burton <paul.burton@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/clocksource.h>
+#include <linux/init.h>
+#include <linux/irqchip/mips-gic.h>
+#include <linux/types.h>
+
+#include <asm/irq.h>
+
+int get_c0_fdc_int(void)
+{
+ int mips_cpu_fdc_irq;
+
+ if (cpu_has_veic)
+ panic("Unimplemented!");
+ else if (gic_present)
+ mips_cpu_fdc_irq = gic_get_c0_fdc_int();
+ else if (cp0_fdc_irq >= 0)
+ mips_cpu_fdc_irq = MIPS_CPU_IRQ_BASE + cp0_fdc_irq;
+ else
+ mips_cpu_fdc_irq = -1;
+
+ return mips_cpu_fdc_irq;
+}
+
+int get_c0_perfcount_int(void)
+{
+ int mips_cpu_perf_irq;
+
+ if (cpu_has_veic)
+ panic("Unimplemented!");
+ else if (gic_present)
+ mips_cpu_perf_irq = gic_get_c0_perfcount_int();
+ else if (cp0_perfcount_irq >= 0)
+ mips_cpu_perf_irq = MIPS_CPU_IRQ_BASE + cp0_perfcount_irq;
+ else
+ mips_cpu_perf_irq = -1;
+
+ return mips_cpu_perf_irq;
+}
+
+unsigned int get_c0_compare_int(void)
+{
+ int mips_cpu_timer_irq;
+
+ if (cpu_has_veic)
+ panic("Unimplemented!");
+ else if (gic_present)
+ mips_cpu_timer_irq = gic_get_c0_compare_int();
+ else
+ mips_cpu_timer_irq = MIPS_CPU_IRQ_BASE + cp0_compare_irq;
+
+ return mips_cpu_timer_irq;
+}
diff --git a/arch/mips/generic/proc.c b/arch/mips/generic/proc.c
new file mode 100644
index 000000000000..42b33250a4a2
--- /dev/null
+++ b/arch/mips/generic/proc.c
@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ * Author: Paul Burton <paul.burton@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/of.h>
+
+#include <asm/bootinfo.h>
+
+const char *get_system_type(void)
+{
+ const char *str;
+ int err;
+
+ err = of_property_read_string(of_root, "model", &str);
+ if (!err)
+ return str;
+
+ err = of_property_read_string_index(of_root, "compatible", 0, &str);
+ if (!err)
+ return str;
+
+ return "Unknown";
+}
diff --git a/arch/mips/generic/vmlinux.its.S b/arch/mips/generic/vmlinux.its.S
new file mode 100644
index 000000000000..f67fbf1c8541
--- /dev/null
+++ b/arch/mips/generic/vmlinux.its.S
@@ -0,0 +1,31 @@
+/dts-v1/;
+
+/ {
+ description = KERNEL_NAME;
+ #address-cells = <ADDR_CELLS>;
+
+ images {
+ kernel@0 {
+ description = KERNEL_NAME;
+ data = /incbin/(VMLINUX_BINARY);
+ type = "kernel";
+ arch = "mips";
+ os = "linux";
+ compression = VMLINUX_COMPRESSION;
+ load = /bits/ ADDR_BITS <VMLINUX_LOAD_ADDRESS>;
+ entry = /bits/ ADDR_BITS <VMLINUX_ENTRY_ADDRESS>;
+ hash@0 {
+ algo = "sha1";
+ };
+ };
+ };
+
+ configurations {
+ default = "conf@default";
+
+ conf@default {
+ description = "Generic Linux kernel";
+ kernel = "kernel@0";
+ };
+ };
+};