linux/linux-5.4.31/arch/mips/generic/board-ocelot.c

79 lines
1.8 KiB
C

// SPDX-License-Identifier: (GPL-2.0 OR MIT)
/*
* Microsemi MIPS SoC support
*
* Copyright (c) 2017 Microsemi Corporation
*/
#include <asm/machine.h>
#include <asm/prom.h>
#define DEVCPU_GCB_CHIP_REGS_CHIP_ID 0x71070000
#define CHIP_ID_PART_ID GENMASK(27, 12)
#define OCELOT_PART_ID (0x7514 << 12)
#define UART_UART 0x70100000
static __init bool ocelot_detect(void)
{
u32 rev;
int idx;
/* Look for the TLB entry set up by redboot before trying to use it */
write_c0_entryhi(DEVCPU_GCB_CHIP_REGS_CHIP_ID);
mtc0_tlbw_hazard();
tlb_probe();
tlb_probe_hazard();
idx = read_c0_index();
if (idx < 0)
return 0;
/* A TLB entry exists, lets assume its usable and check the CHIP ID */
rev = __raw_readl((void __iomem *)DEVCPU_GCB_CHIP_REGS_CHIP_ID);
if ((rev & CHIP_ID_PART_ID) != OCELOT_PART_ID)
return 0;
/* Copy command line from bootloader early for Initrd detection */
if (fw_arg0 < 10 && (fw_arg1 & 0xFFF00000) == 0x80000000) {
unsigned int prom_argc = fw_arg0;
const char **prom_argv = (const char **)fw_arg1;
if (prom_argc > 1 && strlen(prom_argv[1]) > 0)
/* ignore all built-in args if any f/w args given */
strcpy(arcs_cmdline, prom_argv[1]);
}
return 1;
}
static void __init ocelot_earlyprintk_init(void)
{
void __iomem *uart_base;
uart_base = ioremap_nocache(UART_UART, 0x20);
setup_8250_early_printk_port((unsigned long)uart_base, 2, 50000);
}
static void __init ocelot_late_init(void)
{
ocelot_earlyprintk_init();
}
static __init const void *ocelot_fixup_fdt(const void *fdt,
const void *match_data)
{
/* This has to be done so late because ioremap needs to work */
late_time_init = ocelot_late_init;
return fdt;
}
extern char __dtb_ocelot_pcb123_begin[];
MIPS_MACHINE(ocelot) = {
.fdt = __dtb_ocelot_pcb123_begin,
.fixup_fdt = ocelot_fixup_fdt,
.detect = ocelot_detect,
};