@@ -16,6 +16,7 @@ Table of Contents
2) Entry point for arch/powerpc
3) Entry point for arch/x86
4) Entry point for arch/mips/bmips
+ 5) Entry point for arch/sh
II - The DT block format
1) Header
@@ -316,6 +317,18 @@ it with special cases.
This convention is defined for 32-bit systems only, as there are not
currently any 64-bit BMIPS implementations.
+5) Entry point for arch/sh
+--------------------------
+
+ Device-tree-compatible SH bootloaders are expected to provide the physical
+ address of the device tree blob in r4. Since legacy bootloaders did not
+ guarantee any particular initial register state, kernels built to
+ inter-operate with old bootloaders must either use a builtin DTB or
+ select a legacy board option (something other than CONFIG_SH_DEVICE_TREE)
+ that does not use device tree. Support for the latter is being phased out
+ in favor of device tree.
+
+
II - The DT block format
========================
@@ -6,6 +6,21 @@ config SOLUTION_ENGINE
config SH_ALPHA_BOARD
bool
+config SH_DEVICE_TREE
+ bool "Board Described by Device Tree"
+ select OF
+ select OF_EARLY_FLATTREE
+ select CLKSRC_OF
+ select GENERIC_CALIBRATE_DELAY
+ help
+ Select Board Described by Device Tree to build a kernel that
+ does not hard-code any board-specific knowledge but instead uses
+ a device tree blob provided by the boot-loader. You must enable
+ drivers for any hardware you want to use separately. At this
+ time, only boards based on the open-hardware J-Core processors
+ have sufficient driver coverage to use this option; do not
+ select it if you are using original SuperH hardware.
+
config SH_SOLUTION_ENGINE
bool "SolutionEngine"
select SOLUTION_ENGINE
@@ -15,3 +15,5 @@ obj-$(CONFIG_SH_TITAN) += board-titan.o
obj-$(CONFIG_SH_SH7757LCR) += board-sh7757lcr.o
obj-$(CONFIG_SH_APSH4A3A) += board-apsh4a3a.o
obj-$(CONFIG_SH_APSH4AD0A) += board-apsh4ad0a.o
+
+obj-$(CONFIG_SH_DEVICE_TREE) += of-generic.o
new file mode 100644
@@ -0,0 +1,113 @@
+/*
+ * SH generic board support, using device tree
+ *
+ * Copyright (C) 2015-2016 Smart Energy Instruments, Inc.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/of_fdt.h>
+#include <linux/of_iommu.h>
+#include <linux/clocksource.h>
+#include <linux/irqchip.h>
+#include <linux/clk-provider.h>
+#include <asm/machvec.h>
+#include <asm/rtc.h>
+
+static void noop(void)
+{
+}
+
+static int noopi(void)
+{
+ return 0;
+}
+
+static void __init sh_of_mem_reserve(void)
+{
+ early_init_fdt_reserve_self();
+ early_init_fdt_scan_reserved_mem();
+}
+
+static void __init sh_of_time_init(void)
+{
+ pr_info("SH generic board support: scanning for clocksource devices\n");
+ clocksource_probe();
+}
+
+static void __init sh_of_setup(char **cmdline_p)
+{
+ unflatten_device_tree();
+
+ board_time_init = sh_of_time_init;
+
+ sh_mv.mv_name = of_flat_dt_get_machine_name();
+ if (!sh_mv.mv_name)
+ sh_mv.mv_name = "Unknown SH model";
+
+ /* FIXME: register smp ops to use dt to find cpus, use
+ * cpu enable-method, and use irq controller's ipi
+ * functions. */
+}
+
+static int sh_of_irq_demux(int irq)
+{
+ /* FIXME: eventually this should not be used at all;
+ * the interrupt controller should set_handle_irq(). */
+ return irq;
+}
+
+static void __init sh_of_init_irq(void)
+{
+ pr_info("SH generic board support: scanning for interrupt controllers\n");
+ irqchip_init();
+}
+
+static int __init sh_of_clk_init(void)
+{
+#ifdef CONFIG_COMMON_CLK
+ /* Disabled pending move to COMMON_CLK framework. */
+ pr_info("SH generic board support: scanning for clk providers\n");
+ of_clk_init(NULL);
+#endif
+ return 0;
+}
+
+static struct sh_machine_vector __initmv sh_of_generic_mv = {
+ .mv_setup = sh_of_setup,
+ .mv_name = "devicetree", /* replaced by DT root's model */
+ .mv_irq_demux = sh_of_irq_demux,
+ .mv_init_irq = sh_of_init_irq,
+ .mv_clk_init = sh_of_clk_init,
+ .mv_mode_pins = noopi,
+ .mv_mem_init = noop,
+ .mv_mem_reserve = sh_of_mem_reserve,
+};
+
+struct sh_clk_ops;
+
+void __init arch_init_clk_ops(struct sh_clk_ops **ops, int idx)
+{
+}
+
+void __init plat_irq_setup(void)
+{
+}
+
+static int __init sh_of_device_init(void)
+{
+ pr_info("SH generic board support: populating platform devices\n");
+ if (of_have_populated_dt()) {
+ of_iommu_init();
+ of_platform_populate(NULL, of_default_bus_match_table,
+ NULL, NULL);
+ } else {
+ pr_crit("Device tree not populated\n");
+ }
+ return 0;
+}
+arch_initcall_sync(sh_of_device_init);
@@ -66,6 +66,10 @@ ENTRY(_stext)
mov #0, r0
ldc r0, r6_bank
#endif
+
+#ifdef CONFIG_OF
+ mov r4, r12 ! Store device tree blob pointer in r12
+#endif
/*
* Prefetch if possible to reduce cache miss penalty.
@@ -314,6 +318,12 @@ ENTRY(_stext)
10:
#endif
+#ifdef CONFIG_OF
+ mov.l 8f, r0 ! Make flat device tree available early.
+ jsr @r0
+ mov r12, r4
+#endif
+
! Additional CPU initialization
mov.l 6f, r0
jsr @r0
@@ -339,6 +349,9 @@ ENTRY(stack_start)
5: .long start_kernel
6: .long cpu_init
7: .long init_thread_union
+#if defined(CONFIG_OF)
+8: .long sh_fdt_init
+#endif
#ifdef CONFIG_PMB
.LPMB_ADDR: .long PMB_ADDR
@@ -29,6 +29,8 @@
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/memblock.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/page.h>
@@ -172,6 +174,7 @@ disable:
#endif
}
+#ifndef CONFIG_GENERIC_CALIBRATE_DELAY
void calibrate_delay(void)
{
struct clk *clk = clk_get(NULL, "cpu_clk");
@@ -187,6 +190,7 @@ void calibrate_delay(void)
(loops_per_jiffy/(5000/HZ)) % 100,
loops_per_jiffy);
}
+#endif
void __init __add_active_range(unsigned int nid, unsigned long start_pfn,
unsigned long end_pfn)
@@ -238,6 +242,29 @@ void __init __weak plat_early_device_setup(void)
{
}
+#ifdef CONFIG_OF
+void __ref sh_fdt_init(phys_addr_t dt_phys)
+{
+ static int done = 0;
+ void *dt_virt;
+
+ /* Avoid calling an __init function on secondary cpus. */
+ if (done) return;
+
+ dt_virt = phys_to_virt(dt_phys);
+
+ if (!dt_virt || !early_init_dt_scan(dt_virt)) {
+ pr_crit("Error: invalid device tree blob"
+ " at physical address %p\n", (void *)dt_phys);
+
+ while (true)
+ cpu_relax();
+ }
+
+ done = 1;
+}
+#endif
+
void __init setup_arch(char **cmdline_p)
{
enable_mmu();