/*
* 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 <asm/cacheflush.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 void __iomem *pmu_base_addr;
static inline bool pmu_power_domain_is_on(int pd)
{
return !(readl_relaxed(pmu_base_addr + PMU_PWRDN_ST) & BIT(pd));
}
static void pmu_set_power_domain(int pd, bool on)
{
u32 val = readl_relaxed(pmu_base_addr + PMU_PWRDN_CON);
if (on)
val &= ~BIT(pd);
else
val |= BIT(pd);
writel(val, pmu_base_addr + PMU_PWRDN_CON);
while (pmu_power_domain_is_on(pd) != on) { }
}
/*
* Handling of CPU cores
*/
static int __cpuinit rockchip_boot_secondary(unsigned int cpu,
struct task_struct *idle)
{
if (!sram_base_addr || !pmu_base_addr) {
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 */
pmu_set_power_domain(0 + cpu, true);
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 %s\n",
__func__, node->full_name);
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;
}
sram_base_addr = of_iomap(node, 0);
/* set the boot function for the sram code */
rockchip_boot_fn = virt_to_phys(rockchip_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 void __init rockchip_smp_prepare_cpus(unsigned int max_cpus)
{
struct device_node *node;
unsigned int i;
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;
}
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;
}
if (rockchip_smp_prepare_sram(node))
return;
node = of_find_compatible_node(NULL, NULL, "rockchip,rk3066-pmu");
if (!node) {
pr_err("%s: could not find sram dt node\n", __func__);
return;
}
pmu_base_addr = of_iomap(node, 0);
if (!pmu_base_addr) {
pr_err("%s: could not map pmu registers\n", __func__);
return;
}
/* enable the SCU power domain */
pmu_set_power_domain(PMU_PWRDN_SCU, true);
/*
* 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);
scu_enable(scu_base_addr);
/* Make sure that all cores except the first are really off */
for (i = 1; i < ncores; i++)
pmu_set_power_domain(0 + i, false);
}
struct smp_operations rockchip_smp_ops __initdata = {
.smp_prepare_cpus = rockchip_smp_prepare_cpus,
.smp_boot_secondary = rockchip_boot_secondary,
};
