u-boot/arch/riscv/lib/andes_plic.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2019, Rick Chen <rick@andestech.com>
*
* U-Boot syscon driver for Andes's Platform Level Interrupt Controller (PLIC).
* The PLIC block holds memory-mapped claim and pending registers
* associated with software interrupt.
*/
#include <common.h>
#include <dm.h>
#include <dm/device-internal.h>
#include <dm/lists.h>
#include <dm/uclass-internal.h>
#include <regmap.h>
#include <syscon.h>
#include <asm/io.h>
#include <asm/syscon.h>
#include <cpu.h>
/* pending register */
#define PENDING_REG(base, hart) ((ulong)(base) + 0x1000 + ((hart) / 4) * 4)
/* enable register */
#define ENABLE_REG(base, hart) ((ulong)(base) + 0x2000 + (hart) * 0x80)
/* claim register */
#define CLAIM_REG(base, hart) ((ulong)(base) + 0x200004 + (hart) * 0x1000)
#define ENABLE_HART_IPI (0x80808080)
#define SEND_IPI_TO_HART(hart) (0x80 >> (hart))
DECLARE_GLOBAL_DATA_PTR;
static int init_plic(void);
#define PLIC_BASE_GET(void) \
do { \
long *ret; \
\
if (!gd->arch.plic) { \
ret = syscon_get_first_range(RISCV_SYSCON_PLIC); \
if (IS_ERR(ret)) \
return PTR_ERR(ret); \
gd->arch.plic = ret; \
init_plic(); \
} \
} while (0)
static int enable_ipi(int hart)
{
unsigned int en;
en = ENABLE_HART_IPI >> hart;
writel(en, (void __iomem *)ENABLE_REG(gd->arch.plic, hart));
return 0;
}
static int init_plic(void)
{
struct udevice *dev;
ofnode node;
int ret;
u32 reg;
ret = uclass_find_first_device(UCLASS_CPU, &dev);
if (ret)
return ret;
if (ret == 0 && dev) {
ofnode_for_each_subnode(node, dev_ofnode(dev->parent)) {
const char *device_type;
device_type = ofnode_read_string(node, "device_type");
if (!device_type)
continue;
if (strcmp(device_type, "cpu"))
continue;
/* skip if hart is marked as not available */
if (!ofnode_is_available(node))
continue;
/* read hart ID of CPU */
ret = ofnode_read_u32(node, "reg", &reg);
if (ret == 0)
enable_ipi(reg);
}
return 0;
}
return -ENODEV;
}
int riscv_send_ipi(int hart)
{
unsigned int ipi;
PLIC_BASE_GET();
ipi = (SEND_IPI_TO_HART(hart) << (8 * gd->arch.boot_hart));
writel(ipi, (void __iomem *)PENDING_REG(gd->arch.plic,
gd->arch.boot_hart));
return 0;
}
int riscv_clear_ipi(int hart)
{
u32 source_id;
PLIC_BASE_GET();
source_id = readl((void __iomem *)CLAIM_REG(gd->arch.plic, hart));
writel(source_id, (void __iomem *)CLAIM_REG(gd->arch.plic, hart));
return 0;
}
int riscv_get_ipi(int hart, int *pending)
{
PLIC_BASE_GET();
*pending = readl((void __iomem *)PENDING_REG(gd->arch.plic,
gd->arch.boot_hart));
*pending = !!(*pending & SEND_IPI_TO_HART(hart));
return 0;
}
static const struct udevice_id andes_plic_ids[] = {
{ .compatible = "riscv,plic1", .data = RISCV_SYSCON_PLIC },
{ }
};
U_BOOT_DRIVER(andes_plic) = {
.name = "andes_plic",
.id = UCLASS_SYSCON,
.of_match = andes_plic_ids,
.flags = DM_FLAG_PRE_RELOC,
};