linux/arch/arm/mach-shmobile/setup-r8a7779.c
Geert Uytterhoeven 408324a3c5 ARM: shmobile: Enable ARM_GLOBAL_TIMER on Cortex-A9 MPCore SoCs
SH-Mobile AG5 and R-Car H1 SoCs are based on the Cortex-A9 MPCore, which
includes a global timer.

Enable the ARM global timer on these SoCs, which will be used for:
  - the scheduler clock, improving scheduler accuracy from 10 ms to 3 or
    4 ns,
  - delay loops, allowing removal of calls to shmobile_init_delay() from
    the corresponding machine vectors.

Note that when using an old DTB lacking the global timer, the kernel
will still work.  However, loops-per-jiffies will no longer be preset,
and the delay loop will need to be calibrated during boot.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20191211135222.26770-5-geert+renesas@glider.be
2020-02-10 13:44:29 +01:00

79 lines
1.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* r8a7779 processor support
*
* Copyright (C) 2011, 2013 Renesas Solutions Corp.
* Copyright (C) 2011 Magnus Damm
* Copyright (C) 2013 Cogent Embedded, Inc.
*/
#include <linux/init.h>
#include <linux/irqchip.h>
#include <asm/mach/arch.h>
#include <asm/mach/map.h>
#include "common.h"
#include "r8a7779.h"
static struct map_desc r8a7779_io_desc[] __initdata = {
/* 2M identity mapping for 0xf0000000 (MPCORE) */
{
.virtual = 0xf0000000,
.pfn = __phys_to_pfn(0xf0000000),
.length = SZ_2M,
.type = MT_DEVICE_NONSHARED
},
/* 16M identity mapping for 0xfexxxxxx (DMAC-S/HPBREG/INTC2/LRAM/DBSC) */
{
.virtual = 0xfe000000,
.pfn = __phys_to_pfn(0xfe000000),
.length = SZ_16M,
.type = MT_DEVICE_NONSHARED
},
};
static void __init r8a7779_map_io(void)
{
debug_ll_io_init();
iotable_init(r8a7779_io_desc, ARRAY_SIZE(r8a7779_io_desc));
}
/* IRQ */
#define INT2SMSKCR0 IOMEM(0xfe7822a0)
#define INT2SMSKCR1 IOMEM(0xfe7822a4)
#define INT2SMSKCR2 IOMEM(0xfe7822a8)
#define INT2SMSKCR3 IOMEM(0xfe7822ac)
#define INT2SMSKCR4 IOMEM(0xfe7822b0)
#define INT2NTSR0 IOMEM(0xfe700060)
#define INT2NTSR1 IOMEM(0xfe700064)
static void __init r8a7779_init_irq_dt(void)
{
irqchip_init();
/* route all interrupts to ARM */
__raw_writel(0xffffffff, INT2NTSR0);
__raw_writel(0x3fffffff, INT2NTSR1);
/* unmask all known interrupts in INTCS2 */
__raw_writel(0xfffffff0, INT2SMSKCR0);
__raw_writel(0xfff7ffff, INT2SMSKCR1);
__raw_writel(0xfffbffdf, INT2SMSKCR2);
__raw_writel(0xbffffffc, INT2SMSKCR3);
__raw_writel(0x003fee3f, INT2SMSKCR4);
}
static const char *const r8a7779_compat_dt[] __initconst = {
"renesas,r8a7779",
NULL,
};
DT_MACHINE_START(R8A7779_DT, "Generic R8A7779 (Flattened Device Tree)")
.smp = smp_ops(r8a7779_smp_ops),
.map_io = r8a7779_map_io,
.init_irq = r8a7779_init_irq_dt,
.init_late = shmobile_init_late,
.dt_compat = r8a7779_compat_dt,
MACHINE_END