1 files changed, 279 insertions, 0 deletions
diff --git a/arch/arm/mach-exynos/mcpm-exynos.c b/arch/arm/mach-exynos/mcpm-exynos.c
new file mode 100644
index 000000000..9bdf54795
--- /dev/null
+++ b/arch/arm/mach-exynos/mcpm-exynos.c
@@ -0,0 +1,279 @@
+/*
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * arch/arm/mach-exynos/mcpm-exynos.c
+ *
+ * Based on arch/arm/mach-vexpress/dcscb.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/arm-cci.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/syscore_ops.h>
+
+#include <asm/cputype.h>
+#include <asm/cp15.h>
+#include <asm/mcpm.h>
+
+#include "regs-pmu.h"
+#include "common.h"
+
+#define EXYNOS5420_CPUS_PER_CLUSTER	4
+#define EXYNOS5420_NR_CLUSTERS		2
+
+#define EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN	BIT(9)
+#define EXYNOS5420_USE_ARM_CORE_DOWN_STATE	BIT(29)
+#define EXYNOS5420_USE_L2_COMMON_UP_STATE	BIT(30)
+
+static void __iomem *ns_sram_base_addr;
+
+/*
+ * The common v7_exit_coherency_flush API could not be used because of the
+ * Erratum 799270 workaround. This macro is the same as the common one (in
+ * arch/arm/include/asm/cacheflush.h) except for the erratum handling.
+ */
+#define exynos_v7_exit_coherency_flush(level) \
+	asm volatile( \
+	"stmfd	sp!, {fp, ip}\n\t"\
+	"mrc	p15, 0, r0, c1, c0, 0	@ get SCTLR\n\t" \
+	"bic	r0, r0, #"__stringify(CR_C)"\n\t" \
+	"mcr	p15, 0, r0, c1, c0, 0	@ set SCTLR\n\t" \
+	"isb\n\t"\
+	"bl	v7_flush_dcache_"__stringify(level)"\n\t" \
+	"mrc	p15, 0, r0, c1, c0, 1	@ get ACTLR\n\t" \
+	"bic	r0, r0, #(1 << 6)	@ disable local coherency\n\t" \
+	/* Dummy Load of a device register to avoid Erratum 799270 */ \
+	"ldr	r4, [%0]\n\t" \
+	"and	r4, r4, #0\n\t" \
+	"orr	r0, r0, r4\n\t" \
+	"mcr	p15, 0, r0, c1, c0, 1	@ set ACTLR\n\t" \
+	"isb\n\t" \
+	"dsb\n\t" \
+	"ldmfd	sp!, {fp, ip}" \
+	: \
+	: "Ir" (pmu_base_addr + S5P_INFORM0) \
+	: "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", \
+	  "r9", "r10", "lr", "memory")
+
+static int exynos_cpu_powerup(unsigned int cpu, unsigned int cluster)
+{
+	unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER);
+
+	pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
+	if (cpu >= EXYNOS5420_CPUS_PER_CLUSTER ||
+		cluster >= EXYNOS5420_NR_CLUSTERS)
+		return -EINVAL;
+
+	exynos_cpu_power_up(cpunr);
+	return 0;
+}
+
+static int exynos_cluster_powerup(unsigned int cluster)
+{
+	pr_debug("%s: cluster %u\n", __func__, cluster);
+	if (cluster >= EXYNOS5420_NR_CLUSTERS)
+		return -EINVAL;
+
+	exynos_cluster_power_up(cluster);
+	return 0;
+}
+
+static void exynos_cpu_powerdown_prepare(unsigned int cpu, unsigned int cluster)
+{
+	unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER);
+
+	pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
+	BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER ||
+			cluster >= EXYNOS5420_NR_CLUSTERS);
+	exynos_cpu_power_down(cpunr);
+}
+
+static void exynos_cluster_powerdown_prepare(unsigned int cluster)
+{
+	pr_debug("%s: cluster %u\n", __func__, cluster);
+	BUG_ON(cluster >= EXYNOS5420_NR_CLUSTERS);
+	exynos_cluster_power_down(cluster);
+}
+
+static void exynos_cpu_cache_disable(void)
+{
+	/* Disable and flush the local CPU cache. */
+	exynos_v7_exit_coherency_flush(louis);
+}
+
+static void exynos_cluster_cache_disable(void)
+{
+	if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A15) {
+		/*
+		 * On the Cortex-A15 we need to disable
+		 * L2 prefetching before flushing the cache.
+		 */
+		asm volatile(
+		"mcr	p15, 1, %0, c15, c0, 3\n\t"
+		"isb\n\t"
+		"dsb"
+		: : "r" (0x400));
+	}
+
+	/* Flush all cache levels for this cluster. */
+	exynos_v7_exit_coherency_flush(all);
+
+	/*
+	 * Disable cluster-level coherency by masking
+	 * incoming snoops and DVM messages:
+	 */
+	cci_disable_port_by_cpu(read_cpuid_mpidr());
+}
+
+static int exynos_wait_for_powerdown(unsigned int cpu, unsigned int cluster)
+{
+	unsigned int tries = 100;
+	unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER);
+
+	pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
+	BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER ||
+			cluster >= EXYNOS5420_NR_CLUSTERS);
+
+	/* Wait for the core state to be OFF */
+	while (tries--) {
+		if ((exynos_cpu_power_state(cpunr) == 0))
+			return 0; /* success: the CPU is halted */
+
+		/* Otherwise, wait and retry: */
+		msleep(1);
+	}
+
+	return -ETIMEDOUT; /* timeout */
+}
+
+static void exynos_cpu_is_up(unsigned int cpu, unsigned int cluster)
+{
+	/* especially when resuming: make sure power control is set */
+	exynos_cpu_powerup(cpu, cluster);
+}
+
+static const struct mcpm_platform_ops exynos_power_ops = {
+	.cpu_powerup		= exynos_cpu_powerup,
+	.cluster_powerup	= exynos_cluster_powerup,
+	.cpu_powerdown_prepare	= exynos_cpu_powerdown_prepare,
+	.cluster_powerdown_prepare = exynos_cluster_powerdown_prepare,
+	.cpu_cache_disable	= exynos_cpu_cache_disable,
+	.cluster_cache_disable	= exynos_cluster_cache_disable,
+	.wait_for_powerdown	= exynos_wait_for_powerdown,
+	.cpu_is_up		= exynos_cpu_is_up,
+};
+
+/*
+ * Enable cluster-level coherency, in preparation for turning on the MMU.
+ */
+static void __naked exynos_pm_power_up_setup(unsigned int affinity_level)
+{
+	asm volatile ("\n"
+	"cmp	r0, #1\n"
+	"bxne	lr\n"
+	"b	cci_enable_port_for_self");
+}
+
+static const struct of_device_id exynos_dt_mcpm_match[] = {
+	{ .compatible = "samsung,exynos5420" },
+	{ .compatible = "samsung,exynos5800" },
+	{},
+};
+
+static void exynos_mcpm_setup_entry_point(void)
+{
+	/*
+	 * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
+	 * as part of secondary_cpu_start().  Let's redirect it to the
+	 * mcpm_entry_point(). This is done during both secondary boot-up as
+	 * well as system resume.
+	 */
+	__raw_writel(0xe59f0000, ns_sram_base_addr);     /* ldr r0, [pc, #0] */
+	__raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx  r0 */
+	__raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
+}
+
+static struct syscore_ops exynos_mcpm_syscore_ops = {
+	.resume	= exynos_mcpm_setup_entry_point,
+};
+
+static int __init exynos_mcpm_init(void)
+{
+	struct device_node *node;
+	unsigned int value, i;
+	int ret;
+
+	node = of_find_matching_node(NULL, exynos_dt_mcpm_match);
+	if (!node)
+		return -ENODEV;
+	of_node_put(node);
+
+	if (!cci_probed())
+		return -ENODEV;
+
+	node = of_find_compatible_node(NULL, NULL,
+			"samsung,exynos4210-sysram-ns");
+	if (!node)
+		return -ENODEV;
+
+	ns_sram_base_addr = of_iomap(node, 0);
+	of_node_put(node);
+	if (!ns_sram_base_addr) {
+		pr_err("failed to map non-secure iRAM base address\n");
+		return -ENOMEM;
+	}
+
+	/*
+	 * To increase the stability of KFC reset we need to program
+	 * the PMU SPARE3 register
+	 */
+	pmu_raw_writel(EXYNOS5420_SWRESET_KFC_SEL, S5P_PMU_SPARE3);
+
+	ret = mcpm_platform_register(&exynos_power_ops);
+	if (!ret)
+		ret = mcpm_sync_init(exynos_pm_power_up_setup);
+	if (!ret)
+		ret = mcpm_loopback(exynos_cluster_cache_disable); /* turn on the CCI */
+	if (ret) {
+		iounmap(ns_sram_base_addr);
+		return ret;
+	}
+
+	mcpm_smp_set_ops();
+
+	pr_info("Exynos MCPM support installed\n");
+
+	/*
+	 * On Exynos5420/5800 for the A15 and A7 clusters:
+	 *
+	 * EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN ensures that all the cores
+	 * in a cluster are turned off before turning off the cluster L2.
+	 *
+	 * EXYNOS5420_USE_ARM_CORE_DOWN_STATE ensures that a cores is powered
+	 * off before waking it up.
+	 *
+	 * EXYNOS5420_USE_L2_COMMON_UP_STATE ensures that cluster L2 will be
+	 * turned on before the first man is powered up.
+	 */
+	for (i = 0; i < EXYNOS5420_NR_CLUSTERS; i++) {
+		value = pmu_raw_readl(EXYNOS_COMMON_OPTION(i));
+		value |= EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN |
+			 EXYNOS5420_USE_ARM_CORE_DOWN_STATE    |
+			 EXYNOS5420_USE_L2_COMMON_UP_STATE;
+		pmu_raw_writel(value, EXYNOS_COMMON_OPTION(i));
+	}
+
+	exynos_mcpm_setup_entry_point();
+
+	register_syscore_ops(&exynos_mcpm_syscore_ops);
+
+	return ret;
+}
+
+early_initcall(exynos_mcpm_init);