linux/arch/arm/mach-mvebu/board-v7.c
Thomas Petazzoni 8da2b2f7ce ARM: mvebu: reserve the first 10 KB of each memory bank for suspend/resume
When going out of suspend to RAM, the Marvell EBU platforms go through
the bootloader, which re-configures the DRAM controller. To achieve
this, the bootloader executes a piece of code called the "DDR3
training code". It does some reads/writes to the memory to find out
the optimal timings for the memory chip being used.

This has the nasty side effect that the first 10 KB of each DRAM
chip-select are overwritten by the bootloader when exiting the suspend
to RAM state.

Therefore, this commit implements the ->reserve() hook for the 'struct
machine_desc' used on Armada XP, to reserve the 10 KB of each DRAM
chip-select using the memblock API.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1416585613-2113-11-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-11-30 16:40:13 +00:00

294 lines
7.6 KiB
C

/*
* Device Tree support for Armada 370 and XP platforms.
*
* Copyright (C) 2012 Marvell
*
* Lior Amsalem <alior@marvell.com>
* Gregory CLEMENT <gregory.clement@free-electrons.com>
* Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/clk-provider.h>
#include <linux/of_address.h>
#include <linux/of_fdt.h>
#include <linux/of_platform.h>
#include <linux/io.h>
#include <linux/clocksource.h>
#include <linux/dma-mapping.h>
#include <linux/memblock.h>
#include <linux/mbus.h>
#include <linux/signal.h>
#include <linux/slab.h>
#include <linux/irqchip.h>
#include <asm/hardware/cache-l2x0.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>
#include <asm/mach/time.h>
#include <asm/smp_scu.h>
#include "armada-370-xp.h"
#include "common.h"
#include "coherency.h"
#include "mvebu-soc-id.h"
static void __iomem *scu_base;
/*
* Enables the SCU when available. Obviously, this is only useful on
* Cortex-A based SOCs, not on PJ4B based ones.
*/
static void __init mvebu_scu_enable(void)
{
struct device_node *np =
of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
if (np) {
scu_base = of_iomap(np, 0);
scu_enable(scu_base);
of_node_put(np);
}
}
void __iomem *mvebu_get_scu_base(void)
{
return scu_base;
}
/*
* When returning from suspend, the platform goes through the
* bootloader, which executes its DDR3 training code. This code has
* the unfortunate idea of using the first 10 KB of each DRAM bank to
* exercise the RAM and calculate the optimal timings. Therefore, this
* area of RAM is overwritten, and shouldn't be used by the kernel if
* suspend/resume is supported.
*/
#ifdef CONFIG_SUSPEND
#define MVEBU_DDR_TRAINING_AREA_SZ (10 * SZ_1K)
static int __init mvebu_scan_mem(unsigned long node, const char *uname,
int depth, void *data)
{
const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
const __be32 *reg, *endp;
int l;
if (type == NULL || strcmp(type, "memory"))
return 0;
reg = of_get_flat_dt_prop(node, "linux,usable-memory", &l);
if (reg == NULL)
reg = of_get_flat_dt_prop(node, "reg", &l);
if (reg == NULL)
return 0;
endp = reg + (l / sizeof(__be32));
while ((endp - reg) >= (dt_root_addr_cells + dt_root_size_cells)) {
u64 base, size;
base = dt_mem_next_cell(dt_root_addr_cells, &reg);
size = dt_mem_next_cell(dt_root_size_cells, &reg);
memblock_reserve(base, MVEBU_DDR_TRAINING_AREA_SZ);
}
return 0;
}
static void __init mvebu_memblock_reserve(void)
{
of_scan_flat_dt(mvebu_scan_mem, NULL);
}
#else
static void __init mvebu_memblock_reserve(void) {}
#endif
/*
* Early versions of Armada 375 SoC have a bug where the BootROM
* leaves an external data abort pending. The kernel is hit by this
* data abort as soon as it enters userspace, because it unmasks the
* data aborts at this moment. We register a custom abort handler
* below to ignore the first data abort to work around this
* problem.
*/
static int armada_375_external_abort_wa(unsigned long addr, unsigned int fsr,
struct pt_regs *regs)
{
static int ignore_first;
if (!ignore_first && fsr == 0x1406) {
ignore_first = 1;
return 0;
}
return 1;
}
static void __init mvebu_init_irq(void)
{
irqchip_init();
mvebu_scu_enable();
coherency_init();
BUG_ON(mvebu_mbus_dt_init(coherency_available()));
}
static void __init external_abort_quirk(void)
{
u32 dev, rev;
if (mvebu_get_soc_id(&dev, &rev) == 0 && rev > ARMADA_375_Z1_REV)
return;
hook_fault_code(16 + 6, armada_375_external_abort_wa, SIGBUS, 0,
"imprecise external abort");
}
static void __init i2c_quirk(void)
{
struct device_node *np;
u32 dev, rev;
/*
* Only revisons more recent than A0 support the offload
* mechanism. We can exit only if we are sure that we can
* get the SoC revision and it is more recent than A0.
*/
if (mvebu_get_soc_id(&dev, &rev) == 0 && rev > MV78XX0_A0_REV)
return;
for_each_compatible_node(np, NULL, "marvell,mv78230-i2c") {
struct property *new_compat;
new_compat = kzalloc(sizeof(*new_compat), GFP_KERNEL);
new_compat->name = kstrdup("compatible", GFP_KERNEL);
new_compat->length = sizeof("marvell,mv78230-a0-i2c");
new_compat->value = kstrdup("marvell,mv78230-a0-i2c",
GFP_KERNEL);
of_update_property(np, new_compat);
}
return;
}
#define A375_Z1_THERMAL_FIXUP_OFFSET 0xc
static void __init thermal_quirk(void)
{
struct device_node *np;
u32 dev, rev;
int res;
/*
* The early SoC Z1 revision needs a quirk to be applied in order
* for the thermal controller to work properly. This quirk breaks
* the thermal support if applied on a SoC that doesn't need it,
* so we enforce the SoC revision to be known.
*/
res = mvebu_get_soc_id(&dev, &rev);
if (res < 0 || (res == 0 && rev > ARMADA_375_Z1_REV))
return;
for_each_compatible_node(np, NULL, "marvell,armada375-thermal") {
struct property *prop;
__be32 newval, *newprop, *oldprop;
int len;
/*
* The register offset is at a wrong location. This quirk
* creates a new reg property as a clone of the previous
* one and corrects the offset.
*/
oldprop = (__be32 *)of_get_property(np, "reg", &len);
if (!oldprop)
continue;
/* Create a duplicate of the 'reg' property */
prop = kzalloc(sizeof(*prop), GFP_KERNEL);
prop->length = len;
prop->name = kstrdup("reg", GFP_KERNEL);
prop->value = kzalloc(len, GFP_KERNEL);
memcpy(prop->value, oldprop, len);
/* Fixup the register offset of the second entry */
oldprop += 2;
newprop = (__be32 *)prop->value + 2;
newval = cpu_to_be32(be32_to_cpu(*oldprop) -
A375_Z1_THERMAL_FIXUP_OFFSET);
*newprop = newval;
of_update_property(np, prop);
/*
* The thermal controller needs some quirk too, so let's change
* the compatible string to reflect this and allow the driver
* the take the necessary action.
*/
prop = kzalloc(sizeof(*prop), GFP_KERNEL);
prop->name = kstrdup("compatible", GFP_KERNEL);
prop->length = sizeof("marvell,armada375-z1-thermal");
prop->value = kstrdup("marvell,armada375-z1-thermal",
GFP_KERNEL);
of_update_property(np, prop);
}
return;
}
static void __init mvebu_dt_init(void)
{
if (of_machine_is_compatible("plathome,openblocks-ax3-4"))
i2c_quirk();
if (of_machine_is_compatible("marvell,a375-db")) {
external_abort_quirk();
thermal_quirk();
}
of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
}
static const char * const armada_370_xp_dt_compat[] = {
"marvell,armada-370-xp",
NULL,
};
DT_MACHINE_START(ARMADA_370_XP_DT, "Marvell Armada 370/XP (Device Tree)")
.l2c_aux_val = 0,
.l2c_aux_mask = ~0,
.smp = smp_ops(armada_xp_smp_ops),
.init_machine = mvebu_dt_init,
.init_irq = mvebu_init_irq,
.restart = mvebu_restart,
.reserve = mvebu_memblock_reserve,
.dt_compat = armada_370_xp_dt_compat,
MACHINE_END
static const char * const armada_375_dt_compat[] = {
"marvell,armada375",
NULL,
};
DT_MACHINE_START(ARMADA_375_DT, "Marvell Armada 375 (Device Tree)")
.l2c_aux_val = 0,
.l2c_aux_mask = ~0,
.init_irq = mvebu_init_irq,
.init_machine = mvebu_dt_init,
.restart = mvebu_restart,
.dt_compat = armada_375_dt_compat,
MACHINE_END
static const char * const armada_38x_dt_compat[] = {
"marvell,armada380",
"marvell,armada385",
NULL,
};
DT_MACHINE_START(ARMADA_38X_DT, "Marvell Armada 380/385 (Device Tree)")
.l2c_aux_val = 0,
.l2c_aux_mask = ~0,
.init_irq = mvebu_init_irq,
.restart = mvebu_restart,
.dt_compat = armada_38x_dt_compat,
MACHINE_END