ARM: Alpine: smp support

This patch introduces support for waking up secondary CPU cores on
Alpine platform.

Signed-off-by: Barak Wasserstrom <barak@annapurnalabs.com>
Signed-off-by: Tsahee Zidenberg <tsahee@annapurnalabs.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 70 insertions, 0 deletions

diff --git a/arch/arm/mach-alpine/alpine_cpu_pm.c b/arch/arm/mach-alpine/alpine_cpu_pm.c
new file mode 100644
index 000000000000..121c77c4b53c
--- /dev/null
+++ b/arch/arm/mach-alpine/alpine_cpu_pm.c
@@ -0,0 +1,70 @@
+/*
+ * Low-level power-management support for Alpine platform.
+ *
+ * Copyright (C) 2015 Annapurna Labs Ltd.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+#include "alpine_cpu_pm.h"
+#include "alpine_cpu_resume.h"
+
+/* NB registers */
+#define AL_SYSFAB_POWER_CONTROL(cpu)	(0x2000 + (cpu)*0x100 + 0x20)
+
+static struct regmap *al_sysfabric;
+static struct al_cpu_resume_regs __iomem *al_cpu_resume_regs;
+static int wakeup_supported;
+
+int alpine_cpu_wakeup(unsigned int phys_cpu, uint32_t phys_resume_addr)
+{
+	if (!wakeup_supported)
+		return -ENOSYS;
+
+	/*
+	 * Set CPU resume address -
+	 * secure firmware running on boot will jump to this address
+	 * after setting proper CPU mode, and initialiing e.g. secure
+	 * regs (the same mode all CPUs are booted to - usually HYP)
+	 */
+	writel(phys_resume_addr,
+	       &al_cpu_resume_regs->per_cpu[phys_cpu].resume_addr);
+
+	/* Power-up the CPU */
+	regmap_write(al_sysfabric, AL_SYSFAB_POWER_CONTROL(phys_cpu), 0);
+
+	return 0;
+}
+
+void __init alpine_cpu_pm_init(void)
+{
+	struct device_node *np;
+	uint32_t watermark;
+
+	al_sysfabric = syscon_regmap_lookup_by_compatible("al,alpine-sysfabric-service");
+
+	np = of_find_compatible_node(NULL, NULL, "al,alpine-cpu-resume");
+	al_cpu_resume_regs = of_iomap(np, 0);
+
+	wakeup_supported = !IS_ERR(al_sysfabric) && al_cpu_resume_regs;
+
+	if (wakeup_supported) {
+		watermark = readl(&al_cpu_resume_regs->watermark);
+		wakeup_supported = (watermark & AL_CPU_RESUME_MAGIC_NUM_MASK)
+				    == AL_CPU_RESUME_MAGIC_NUM;
+	}
+}