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linux/arch/mips/n64/init.c
Lauri Kasanen baec970aa5 mips: Add N64 machine type
Add support for the Nintendo 64.

Signed-off-by: Lauri Kasanen <cand@gmx.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2021-01-22 11:40:00 +01:00

165 lines
3.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Nintendo 64 init.
*
* Copyright (C) 2021 Lauri Kasanen
*/
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/irq.h>
#include <linux/memblock.h>
#include <linux/platform_device.h>
#include <linux/platform_data/simplefb.h>
#include <linux/string.h>
#include <asm/bootinfo.h>
#include <asm/fw/fw.h>
#include <asm/time.h>
#define IO_MEM_RESOURCE_START 0UL
#define IO_MEM_RESOURCE_END 0x1fffffffUL
/*
* System-specifc irq names for clarity
*/
#define MIPS_CPU_IRQ(x) (MIPS_CPU_IRQ_BASE + (x))
#define MIPS_SOFTINT0_IRQ MIPS_CPU_IRQ(0)
#define MIPS_SOFTINT1_IRQ MIPS_CPU_IRQ(1)
#define RCP_IRQ MIPS_CPU_IRQ(2)
#define CART_IRQ MIPS_CPU_IRQ(3)
#define PRENMI_IRQ MIPS_CPU_IRQ(4)
#define RDBR_IRQ MIPS_CPU_IRQ(5)
#define RDBW_IRQ MIPS_CPU_IRQ(6)
#define TIMER_IRQ MIPS_CPU_IRQ(7)
static void __init iomem_resource_init(void)
{
iomem_resource.start = IO_MEM_RESOURCE_START;
iomem_resource.end = IO_MEM_RESOURCE_END;
}
const char *get_system_type(void)
{
return "Nintendo 64";
}
void __init prom_init(void)
{
fw_init_cmdline();
}
#define W 320
#define H 240
#define REG_BASE ((u32 *) CKSEG1ADDR(0x4400000))
static void __init n64rdp_write_reg(const u8 reg, const u32 value)
{
__raw_writel(value, REG_BASE + reg);
}
#undef REG_BASE
static const u32 ntsc_320[] __initconst = {
0x00013212, 0x00000000, 0x00000140, 0x00000200,
0x00000000, 0x03e52239, 0x0000020d, 0x00000c15,
0x0c150c15, 0x006c02ec, 0x002501ff, 0x000e0204,
0x00000200, 0x00000400
};
#define MI_REG_BASE 0x4300000
#define NUM_MI_REGS 4
#define AI_REG_BASE 0x4500000
#define NUM_AI_REGS 6
#define PI_REG_BASE 0x4600000
#define NUM_PI_REGS 5
#define SI_REG_BASE 0x4800000
#define NUM_SI_REGS 7
static int __init n64_platform_init(void)
{
static const char simplefb_resname[] = "FB";
static const struct simplefb_platform_data mode = {
.width = W,
.height = H,
.stride = W * 2,
.format = "r5g5b5a1"
};
struct resource res[3];
void *orig;
unsigned long phys;
unsigned i;
memset(res, 0, sizeof(struct resource) * 3);
res[0].flags = IORESOURCE_MEM;
res[0].start = MI_REG_BASE;
res[0].end = MI_REG_BASE + NUM_MI_REGS * 4 - 1;
res[1].flags = IORESOURCE_MEM;
res[1].start = AI_REG_BASE;
res[1].end = AI_REG_BASE + NUM_AI_REGS * 4 - 1;
res[2].flags = IORESOURCE_IRQ;
res[2].start = RCP_IRQ;
res[2].end = RCP_IRQ;
platform_device_register_simple("n64audio", -1, res, 3);
memset(&res[0], 0, sizeof(res[0]));
res[0].flags = IORESOURCE_MEM;
res[0].start = PI_REG_BASE;
res[0].end = PI_REG_BASE + NUM_PI_REGS * 4 - 1;
platform_device_register_simple("n64cart", -1, res, 1);
memset(&res[0], 0, sizeof(res[0]));
res[0].flags = IORESOURCE_MEM;
res[0].start = SI_REG_BASE;
res[0].end = SI_REG_BASE + NUM_SI_REGS * 4 - 1;
platform_device_register_simple("n64joy", -1, res, 1);
/* The framebuffer needs 64-byte alignment */
orig = kzalloc(W * H * 2 + 63, GFP_DMA | GFP_KERNEL);
if (!orig)
return -ENOMEM;
phys = virt_to_phys(orig);
phys += 63;
phys &= ~63;
for (i = 0; i < ARRAY_SIZE(ntsc_320); i++) {
if (i == 1)
n64rdp_write_reg(i, phys);
else
n64rdp_write_reg(i, ntsc_320[i]);
}
/* setup IORESOURCE_MEM as framebuffer memory */
memset(&res[0], 0, sizeof(res[0]));
res[0].flags = IORESOURCE_MEM;
res[0].name = simplefb_resname;
res[0].start = phys;
res[0].end = phys + W * H * 2 - 1;
platform_device_register_resndata(NULL, "simple-framebuffer", 0,
&res[0], 1, &mode, sizeof(mode));
return 0;
}
#undef W
#undef H
arch_initcall(n64_platform_init);
void __init plat_mem_setup(void)
{
iomem_resource_init();
memblock_add(0x0, 8 * 1024 * 1024); /* Bootloader blocks the 4mb config */
}
void __init plat_time_init(void)
{
/* 93.75 MHz cpu, count register runs at half rate */
mips_hpt_frequency = 93750000 / 2;
}