1 files changed, 374 insertions, 0 deletions
diff --git a/arch/arm/mach-rockchip/platsmp.c b/arch/arm/mach-rockchip/platsmp.c
new file mode 100644
index 000000000..51984a40b
--- /dev/null
+++ b/arch/arm/mach-rockchip/platsmp.c
@@ -0,0 +1,374 @@
+/*
+ * Copyright (c) 2013 MundoReader S.L.
+ * Author: Heiko Stuebner <heiko@sntech.de>
+ *
+ * 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/delay.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+#include <linux/reset.h>
+#include <linux/cpu.h>
+#include <asm/cacheflush.h>
+#include <asm/cp15.h>
+#include <asm/smp_scu.h>
+#include <asm/smp_plat.h>
+#include <asm/mach/map.h>
+
+#include "core.h"
+
+static void __iomem *scu_base_addr;
+static void __iomem *sram_base_addr;
+static int ncores;
+
+#define PMU_PWRDN_CON		0x08
+#define PMU_PWRDN_ST		0x0c
+
+#define PMU_PWRDN_SCU		4
+
+static struct regmap *pmu;
+static int has_pmu = true;
+
+static int pmu_power_domain_is_on(int pd)
+{
+	u32 val;
+	int ret;
+
+	ret = regmap_read(pmu, PMU_PWRDN_ST, &val);
+	if (ret < 0)
+		return ret;
+
+	return !(val & BIT(pd));
+}
+
+static struct reset_control *rockchip_get_core_reset(int cpu)
+{
+	struct device *dev = get_cpu_device(cpu);
+	struct device_node *np;
+
+	/* The cpu device is only available after the initial core bringup */
+	if (dev)
+		np = dev->of_node;
+	else
+		np = of_get_cpu_node(cpu, NULL);
+
+	return of_reset_control_get_exclusive(np, NULL);
+}
+
+static int pmu_set_power_domain(int pd, bool on)
+{
+	u32 val = (on) ? 0 : BIT(pd);
+	struct reset_control *rstc = rockchip_get_core_reset(pd);
+	int ret;
+
+	if (IS_ERR(rstc) && read_cpuid_part() != ARM_CPU_PART_CORTEX_A9) {
+		pr_err("%s: could not get reset control for core %d\n",
+		       __func__, pd);
+		return PTR_ERR(rstc);
+	}
+
+	/*
+	 * We need to soft reset the cpu when we turn off the cpu power domain,
+	 * or else the active processors might be stalled when the individual
+	 * processor is powered down.
+	 */
+	if (!IS_ERR(rstc) && !on)
+		reset_control_assert(rstc);
+
+	if (has_pmu) {
+		ret = regmap_update_bits(pmu, PMU_PWRDN_CON, BIT(pd), val);
+		if (ret < 0) {
+			pr_err("%s: could not update power domain\n",
+			       __func__);
+			return ret;
+		}
+
+		ret = -1;
+		while (ret != on) {
+			ret = pmu_power_domain_is_on(pd);
+			if (ret < 0) {
+				pr_err("%s: could not read power domain state\n",
+				       __func__);
+				return ret;
+			}
+		}
+	}
+
+	if (!IS_ERR(rstc)) {
+		if (on)
+			reset_control_deassert(rstc);
+		reset_control_put(rstc);
+	}
+
+	return 0;
+}
+
+/*
+ * Handling of CPU cores
+ */
+
+static int rockchip_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+	int ret;
+
+	if (!sram_base_addr || (has_pmu && !pmu)) {
+		pr_err("%s: sram or pmu missing for cpu boot\n", __func__);
+		return -ENXIO;
+	}
+
+	if (cpu >= ncores) {
+		pr_err("%s: cpu %d outside maximum number of cpus %d\n",
+		       __func__, cpu, ncores);
+		return -ENXIO;
+	}
+
+	/* start the core */
+	ret = pmu_set_power_domain(0 + cpu, true);
+	if (ret < 0)
+		return ret;
+
+	if (read_cpuid_part() != ARM_CPU_PART_CORTEX_A9) {
+		/*
+		 * We communicate with the bootrom to active the cpus other
+		 * than cpu0, after a blob of initialize code, they will
+		 * stay at wfe state, once they are actived, they will check
+		 * the mailbox:
+		 * sram_base_addr + 4: 0xdeadbeaf
+		 * sram_base_addr + 8: start address for pc
+		 * The cpu0 need to wait the other cpus other than cpu0 entering
+		 * the wfe state.The wait time is affected by many aspects.
+		 * (e.g: cpu frequency, bootrom frequency, sram frequency, ...)
+		 */
+		mdelay(1); /* ensure the cpus other than cpu0 to startup */
+
+		writel(__pa_symbol(secondary_startup), sram_base_addr + 8);
+		writel(0xDEADBEAF, sram_base_addr + 4);
+		dsb_sev();
+	}
+
+	return 0;
+}
+
+/**
+ * rockchip_smp_prepare_sram - populate necessary sram block
+ * Starting cores execute the code residing at the start of the on-chip sram
+ * after power-on. Therefore make sure, this sram region is reserved and
+ * big enough. After this check, copy the trampoline code that directs the
+ * core to the real startup code in ram into the sram-region.
+ * @node: mmio-sram device node
+ */
+static int __init rockchip_smp_prepare_sram(struct device_node *node)
+{
+	unsigned int trampoline_sz = &rockchip_secondary_trampoline_end -
+					    &rockchip_secondary_trampoline;
+	struct resource res;
+	unsigned int rsize;
+	int ret;
+
+	ret = of_address_to_resource(node, 0, &res);
+	if (ret < 0) {
+		pr_err("%s: could not get address for node %pOF\n",
+		       __func__, node);
+		return ret;
+	}
+
+	rsize = resource_size(&res);
+	if (rsize < trampoline_sz) {
+		pr_err("%s: reserved block with size 0x%x is to small for trampoline size 0x%x\n",
+		       __func__, rsize, trampoline_sz);
+		return -EINVAL;
+	}
+
+	/* set the boot function for the sram code */
+	rockchip_boot_fn = __pa_symbol(secondary_startup);
+
+	/* copy the trampoline to sram, that runs during startup of the core */
+	memcpy(sram_base_addr, &rockchip_secondary_trampoline, trampoline_sz);
+	flush_cache_all();
+	outer_clean_range(0, trampoline_sz);
+
+	dsb_sev();
+
+	return 0;
+}
+
+static const struct regmap_config rockchip_pmu_regmap_config = {
+	.name = "rockchip-pmu",
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+};
+
+static int __init rockchip_smp_prepare_pmu(void)
+{
+	struct device_node *node;
+	void __iomem *pmu_base;
+
+	/*
+	 * This function is only called via smp_ops->smp_prepare_cpu().
+	 * That only happens if a "/cpus" device tree node exists
+	 * and has an "enable-method" property that selects the SMP
+	 * operations defined herein.
+	 */
+	node = of_find_node_by_path("/cpus");
+
+	pmu = syscon_regmap_lookup_by_phandle(node, "rockchip,pmu");
+	of_node_put(node);
+	if (!IS_ERR(pmu))
+		return 0;
+
+	pmu = syscon_regmap_lookup_by_compatible("rockchip,rk3066-pmu");
+	if (!IS_ERR(pmu))
+		return 0;
+
+	/* fallback, create our own regmap for the pmu area */
+	pmu = NULL;
+	node = of_find_compatible_node(NULL, NULL, "rockchip,rk3066-pmu");
+	if (!node) {
+		pr_err("%s: could not find pmu dt node\n", __func__);
+		return -ENODEV;
+	}
+
+	pmu_base = of_iomap(node, 0);
+	if (!pmu_base) {
+		pr_err("%s: could not map pmu registers\n", __func__);
+		return -ENOMEM;
+	}
+
+	pmu = regmap_init_mmio(NULL, pmu_base, &rockchip_pmu_regmap_config);
+	if (IS_ERR(pmu)) {
+		int ret = PTR_ERR(pmu);
+
+		iounmap(pmu_base);
+		pmu = NULL;
+		pr_err("%s: regmap init failed\n", __func__);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void __init rockchip_smp_prepare_cpus(unsigned int max_cpus)
+{
+	struct device_node *node;
+	unsigned int i;
+
+	node = of_find_compatible_node(NULL, NULL, "rockchip,rk3066-smp-sram");
+	if (!node) {
+		pr_err("%s: could not find sram dt node\n", __func__);
+		return;
+	}
+
+	sram_base_addr = of_iomap(node, 0);
+	if (!sram_base_addr) {
+		pr_err("%s: could not map sram registers\n", __func__);
+		return;
+	}
+
+	if (has_pmu && rockchip_smp_prepare_pmu())
+		return;
+
+	if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) {
+		if (rockchip_smp_prepare_sram(node))
+			return;
+
+		/* enable the SCU power domain */
+		pmu_set_power_domain(PMU_PWRDN_SCU, true);
+
+		node = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
+		if (!node) {
+			pr_err("%s: missing scu\n", __func__);
+			return;
+		}
+
+		scu_base_addr = of_iomap(node, 0);
+		if (!scu_base_addr) {
+			pr_err("%s: could not map scu registers\n", __func__);
+			return;
+		}
+
+		/*
+		 * While the number of cpus is gathered from dt, also get the
+		 * number of cores from the scu to verify this value when
+		 * booting the cores.
+		 */
+		ncores = scu_get_core_count(scu_base_addr);
+		pr_err("%s: ncores %d\n", __func__, ncores);
+
+		scu_enable(scu_base_addr);
+	} else {
+		unsigned int l2ctlr;
+
+		asm ("mrc p15, 1, %0, c9, c0, 2\n" : "=r" (l2ctlr));
+		ncores = ((l2ctlr >> 24) & 0x3) + 1;
+	}
+
+	/* Make sure that all cores except the first are really off */
+	for (i = 1; i < ncores; i++)
+		pmu_set_power_domain(0 + i, false);
+}
+
+static void __init rk3036_smp_prepare_cpus(unsigned int max_cpus)
+{
+	has_pmu = false;
+
+	rockchip_smp_prepare_cpus(max_cpus);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static int rockchip_cpu_kill(unsigned int cpu)
+{
+	/*
+	 * We need a delay here to ensure that the dying CPU can finish
+	 * executing v7_coherency_exit() and reach the WFI/WFE state
+	 * prior to having the power domain disabled.
+	 */
+	mdelay(1);
+
+	pmu_set_power_domain(0 + cpu, false);
+	return 1;
+}
+
+static void rockchip_cpu_die(unsigned int cpu)
+{
+	v7_exit_coherency_flush(louis);
+	while (1)
+		cpu_do_idle();
+}
+#endif
+
+static const struct smp_operations rk3036_smp_ops __initconst = {
+	.smp_prepare_cpus	= rk3036_smp_prepare_cpus,
+	.smp_boot_secondary	= rockchip_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+	.cpu_kill		= rockchip_cpu_kill,
+	.cpu_die		= rockchip_cpu_die,
+#endif
+};
+
+static const struct smp_operations rockchip_smp_ops __initconst = {
+	.smp_prepare_cpus	= rockchip_smp_prepare_cpus,
+	.smp_boot_secondary	= rockchip_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+	.cpu_kill		= rockchip_cpu_kill,
+	.cpu_die		= rockchip_cpu_die,
+#endif
+};
+
+CPU_METHOD_OF_DECLARE(rk3036_smp, "rockchip,rk3036-smp", &rk3036_smp_ops);
+CPU_METHOD_OF_DECLARE(rk3066_smp, "rockchip,rk3066-smp", &rockchip_smp_ops);