ARM: milbeaut: Add basic support for Milbeaut m10v SoC

This adds the basic M10V SoC support under arch/arm.
Since all cores are activated in the custom bootloader before booting
linux, it is necessary to wait for the secondary-cores using cpu-enable-
method and special sram.

Signed-off-by: Sugaya Taichi <sugaya.taichi@socionext.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 143 insertions, 0 deletions

diff --git a/arch/arm/mach-milbeaut/platsmp.c b/arch/arm/mach-milbeaut/platsmp.c
new file mode 100644
index 000000000000..591543c81399
--- /dev/null
+++ b/arch/arm/mach-milbeaut/platsmp.c
@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright:	(C) 2018 Socionext Inc.
+ * Copyright:	(C) 2015 Linaro Ltd.
+ */
+
+#include <linux/cpu_pm.h>
+#include <linux/irqchip/arm-gic.h>
+#include <linux/of_address.h>
+#include <linux/suspend.h>
+
+#include <asm/cacheflush.h>
+#include <asm/cp15.h>
+#include <asm/idmap.h>
+#include <asm/smp_plat.h>
+#include <asm/suspend.h>
+
+#define M10V_MAX_CPU	4
+#define KERNEL_UNBOOT_FLAG	0x12345678
+
+static void __iomem *m10v_smp_base;
+
+static int m10v_boot_secondary(unsigned int l_cpu, struct task_struct *idle)
+{
+	unsigned int mpidr, cpu, cluster;
+
+	if (!m10v_smp_base)
+		return -ENXIO;
+
+	mpidr = cpu_logical_map(l_cpu);
+	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+
+	if (cpu >= M10V_MAX_CPU)
+		return -EINVAL;
+
+	pr_info("%s: cpu %u l_cpu %u cluster %u\n",
+			__func__, cpu, l_cpu, cluster);
+
+	writel(__pa_symbol(secondary_startup), m10v_smp_base + cpu * 4);
+	arch_send_wakeup_ipi_mask(cpumask_of(l_cpu));
+
+	return 0;
+}
+
+static void m10v_smp_init(unsigned int max_cpus)
+{
+	unsigned int mpidr, cpu, cluster;
+	struct device_node *np;
+
+	np = of_find_compatible_node(NULL, NULL, "socionext,milbeaut-smp-sram");
+	if (!np)
+		return;
+
+	m10v_smp_base = of_iomap(np, 0);
+	if (!m10v_smp_base)
+		return;
+
+	mpidr = read_cpuid_mpidr();
+	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+	pr_info("MCPM boot on cpu_%u cluster_%u\n", cpu, cluster);
+
+	for (cpu = 0; cpu < M10V_MAX_CPU; cpu++)
+		writel(KERNEL_UNBOOT_FLAG, m10v_smp_base + cpu * 4);
+}
+
+static void m10v_cpu_die(unsigned int l_cpu)
+{
+	gic_cpu_if_down(0);
+	v7_exit_coherency_flush(louis);
+	wfi();
+}
+
+static int m10v_cpu_kill(unsigned int l_cpu)
+{
+	unsigned int mpidr, cpu;
+
+	mpidr = cpu_logical_map(l_cpu);
+	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+
+	writel(KERNEL_UNBOOT_FLAG, m10v_smp_base + cpu * 4);
+
+	return 1;
+}
+
+static struct smp_operations m10v_smp_ops __initdata = {
+	.smp_prepare_cpus	= m10v_smp_init,
+	.smp_boot_secondary	= m10v_boot_secondary,
+	.cpu_die		= m10v_cpu_die,
+	.cpu_kill		= m10v_cpu_kill,
+};
+CPU_METHOD_OF_DECLARE(m10v_smp, "socionext,milbeaut-m10v-smp", &m10v_smp_ops);
+
+static int m10v_pm_valid(suspend_state_t state)
+{
+	return (state == PM_SUSPEND_STANDBY) || (state == PM_SUSPEND_MEM);
+}
+
+typedef void (*phys_reset_t)(unsigned long);
+static phys_reset_t phys_reset;
+
+static int m10v_die(unsigned long arg)
+{
+	setup_mm_for_reboot();
+	asm("wfi");
+	/* Boot just like a secondary */
+	phys_reset = (phys_reset_t)(unsigned long)virt_to_phys(cpu_reset);
+	phys_reset(virt_to_phys(cpu_resume));
+
+	return 0;
+}
+
+static int m10v_pm_enter(suspend_state_t state)
+{
+	switch (state) {
+	case PM_SUSPEND_STANDBY:
+		asm("wfi");
+		break;
+	case PM_SUSPEND_MEM:
+		cpu_pm_enter();
+		cpu_suspend(0, m10v_die);
+		cpu_pm_exit();
+		break;
+	}
+	return 0;
+}
+
+static const struct platform_suspend_ops m10v_pm_ops = {
+	.valid		= m10v_pm_valid,
+	.enter		= m10v_pm_enter,
+};
+
+struct clk *m10v_clclk_register(struct device *cpu_dev);
+
+static int __init m10v_pm_init(void)
+{
+	if (of_machine_is_compatible("socionext,milbeaut-evb"))
+		suspend_set_ops(&m10v_pm_ops);
+
+	return 0;
+}
+late_initcall(m10v_pm_init);