arch/arm/mach-rockchip/platsmp.c - linux - Git at Google

 /*
  * 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);
	/*
	* 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);