/*
* Copyright (C) 2016 Imagination Technologies
* Author: Paul Burton <paul.burton@imgtec.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#define pr_fmt(fmt) "sead3: " fmt
#include <linux/errno.h>
#include <linux/libfdt.h>
#include <linux/printk.h>
#include <asm/fw/fw.h>
#include <asm/io.h>
#include <asm/machine.h>
#define SEAD_CONFIG CKSEG1ADDR(0x1b100110)
#define SEAD_CONFIG_GIC_PRESENT BIT(1)
#define MIPS_REVISION CKSEG1ADDR(0x1fc00010)
#define MIPS_REVISION_MACHINE (0xf << 4)
#define MIPS_REVISION_MACHINE_SEAD3 (0x4 << 4)
static __init bool sead3_detect(void)
{
uint32_t rev;
rev = __raw_readl((void *)MIPS_REVISION);
return (rev & MIPS_REVISION_MACHINE) == MIPS_REVISION_MACHINE_SEAD3;
}
static __init int append_cmdline(void *fdt)
{
int err, chosen_off;
/* find or add chosen node */
chosen_off = fdt_path_offset(fdt, "/chosen");
if (chosen_off == -FDT_ERR_NOTFOUND)
chosen_off = fdt_path_offset(fdt, "/chosen@0");
if (chosen_off == -FDT_ERR_NOTFOUND)
chosen_off = fdt_add_subnode(fdt, 0, "chosen");
if (chosen_off < 0) {
pr_err("Unable to find or add DT chosen node: %d\n",
chosen_off);
return chosen_off;
}
err = fdt_setprop_string(fdt, chosen_off, "bootargs", fw_getcmdline());
if (err) {
pr_err("Unable to set bootargs property: %d\n", err);
return err;
}
return 0;
}
static __init int append_memory(void *fdt)
{
unsigned long phys_memsize, memsize;
__be32 mem_array[2];
int err, mem_off;
char *var;
/* find memory size from the bootloader environment */
var = fw_getenv("memsize");
if (var) {
err = kstrtoul(var, 0, &phys_memsize);
if (err) {
pr_err("Failed to read memsize env variable '%s'\n",
var);
return -EINVAL;
}
} else {
pr_warn("The bootloader didn't provide memsize: defaulting to 32MB\n");
phys_memsize = 32 << 20;
}
/* default to using all available RAM */
memsize = phys_memsize;
/* allow the user to override the usable memory */
var = strstr(arcs_cmdline, "memsize=");
if (var)
memsize = memparse(var + strlen("memsize="), NULL);
/* if the user says there's more RAM than we thought, believe them */
phys_memsize = max_t(unsigned long, phys_memsize, memsize);
/* find or add a memory node */
mem_off = fdt_path_offset(fdt, "/memory");
if (mem_off == -FDT_ERR_NOTFOUND)
mem_off = fdt_add_subnode(fdt, 0, "memory");
if (mem_off < 0) {
pr_err("Unable to find or add memory DT node: %d\n", mem_off);
return mem_off;
}
err = fdt_setprop_string(fdt, mem_off, "device_type", "memory");
if (err) {
pr_err("Unable to set memory node device_type: %d\n", err);
return err;
}
mem_array[0] = 0;
mem_array[1] = cpu_to_be32(phys_memsize);
err = fdt_setprop(fdt, mem_off, "reg", mem_array, sizeof(mem_array));
if (err) {
pr_err("Unable to set memory regs property: %d\n", err);
return err;
}
mem_array[0] = 0;
mem_array[1] = cpu_to_be32(memsize);
err = fdt_setprop(fdt, mem_off, "linux,usable-memory",
mem_array, sizeof(mem_array));
if (err) {
pr_err("Unable to set linux,usable-memory property: %d\n", err);
return err;
}
return 0;
}
static __init int remove_gic(void *fdt)
{
const unsigned int cpu_ehci_int = 2;
const unsigned int cpu_uart_int = 4;
const unsigned int cpu_eth_int = 6;
int gic_off, cpu_off, uart_off, eth_off, ehci_off, err;
uint32_t cfg, cpu_phandle;
/* leave the GIC node intact if a GIC is present */
cfg = __raw_readl((uint32_t *)SEAD_CONFIG);
if (cfg & SEAD_CONFIG_GIC_PRESENT)
return 0;
gic_off = fdt_node_offset_by_compatible(fdt, -1, "mti,gic");
if (gic_off < 0) {
pr_err("unable to find DT GIC node: %d\n", gic_off);
return gic_off;
}
err = fdt_nop_node(fdt, gic_off);
if (err) {
pr_err("unable to nop GIC node\n");
return err;
}
cpu_off = fdt_node_offset_by_compatible(fdt, -1,
"mti,cpu-interrupt-controller");
if (cpu_off < 0) {
pr_err("unable to find CPU intc node: %d\n", cpu_off);
return cpu_off;
}
cpu_phandle = fdt_get_phandle(fdt, cpu_off);
if (!cpu_phandle) {
pr_err("unable to get CPU intc phandle\n");
return -EINVAL;
}
err = fdt_setprop_u32(fdt, 0, "interrupt-parent", cpu_phandle);
if (err) {
pr_err("unable to set root interrupt-parent: %d\n", err);
return err;
}
uart_off = fdt_node_offset_by_compatible(fdt, -1, "ns16550a");
while (uart_off >= 0) {
err = fdt_setprop_u32(fdt, uart_off, "interrupts",
cpu_uart_int);
if (err) {
pr_err("unable to set UART interrupts property: %d\n",
err);
return err;
}
uart_off = fdt_node_offset_by_compatible(fdt, uart_off,
"ns16550a");
}
if (uart_off != -FDT_ERR_NOTFOUND) {
pr_err("error searching for UART DT node: %d\n", uart_off);
return uart_off;
}
eth_off = fdt_node_offset_by_compatible(fdt, -1, "smsc,lan9115");
if (eth_off < 0) {
pr_err("unable to find ethernet DT node: %d\n", eth_off);
return eth_off;
}
err = fdt_setprop_u32(fdt, eth_off, "interrupts", cpu_eth_int);
if (err) {
pr_err("unable to set ethernet interrupts property: %d\n", err);
return err;
}
ehci_off = fdt_node_offset_by_compatible(fdt, -1, "generic-ehci");
if (ehci_off < 0) {
pr_err("unable to find EHCI DT node: %d\n", ehci_off);
return ehci_off;
}
err = fdt_setprop_u32(fdt, ehci_off, "interrupts", cpu_ehci_int);
if (err) {
pr_err("unable to set EHCI interrupts property: %d\n", err);
return err;
}
return 0;
}
static __init int serial_config(void *fdt)
{
const char *yamontty, *mode_var;
char mode_var_name[9], path[18], parity;
unsigned int uart, baud, stop_bits;
bool hw_flow;
int chosen_off, err;
yamontty = fw_getenv("yamontty");
if (!yamontty || !strcmp(yamontty, "tty0")) {
uart = 0;
} else if (!strcmp(yamontty, "tty1")) {
uart = 1;
} else {
pr_warn("yamontty environment variable '%s' invalid\n",
yamontty);
uart = 0;
}
baud = stop_bits = 0;
parity = 0;
hw_flow = false;
snprintf(mode_var_name, sizeof(mode_var_name), "modetty%u", uart);
mode_var = fw_getenv(mode_var_name);
if (mode_var) {
while (mode_var[0] >= '0' && mode_var[0] <= '9') {
baud *= 10;
baud += mode_var[0] - '0';
mode_var++;
}
if (mode_var[0] == ',')
mode_var++;
if (mode_var[0])
parity = mode_var[0];
if (mode_var[0] == ',')
mode_var++;
if (mode_var[0])
stop_bits = mode_var[0] - '0';
if (mode_var[0] == ',')
mode_var++;
if (!strcmp(mode_var, "hw"))
hw_flow = true;
}
if (!baud)
baud = 38400;
if (parity != 'e' && parity != 'n' && parity != 'o')
parity = 'n';
if (stop_bits != 7 && stop_bits != 8)
stop_bits = 8;
WARN_ON(snprintf(path, sizeof(path), "uart%u:%u%c%u%s",
uart, baud, parity, stop_bits,
hw_flow ? "r" : "") >= sizeof(path));
/* find or add chosen node */
chosen_off = fdt_path_offset(fdt, "/chosen");
if (chosen_off == -FDT_ERR_NOTFOUND)
chosen_off = fdt_path_offset(fdt, "/chosen@0");
if (chosen_off == -FDT_ERR_NOTFOUND)
chosen_off = fdt_add_subnode(fdt, 0, "chosen");
if (chosen_off < 0) {
pr_err("Unable to find or add DT chosen node: %d\n",
chosen_off);
return chosen_off;
}
err = fdt_setprop_string(fdt, chosen_off, "stdout-path", path);
if (err) {
pr_err("Unable to set stdout-path property: %d\n", err);
return err;
}
return 0;
}
static __init const void *sead3_fixup_fdt(const void *fdt,
const void *match_data)
{
static unsigned char fdt_buf[16 << 10] __initdata;
int err;
if (fdt_check_header(fdt))
panic("Corrupt DT");
/* if this isn't SEAD3, something went wrong */
BUG_ON(fdt_node_check_compatible(fdt, 0, "mti,sead-3"));
fw_init_cmdline();
err = fdt_open_into(fdt, fdt_buf, sizeof(fdt_buf));
if (err)
panic("Unable to open FDT: %d", err);
err = append_cmdline(fdt_buf);
if (err)
panic("Unable to patch FDT: %d", err);
err = append_memory(fdt_buf);
if (err)
panic("Unable to patch FDT: %d", err);
err = remove_gic(fdt_buf);
if (err)
panic("Unable to patch FDT: %d", err);
err = serial_config(fdt_buf);
if (err)
panic("Unable to patch FDT: %d", err);
err = fdt_pack(fdt_buf);
if (err)
panic("Unable to pack FDT: %d\n", err);
return fdt_buf;
}
static __init unsigned int sead3_measure_hpt_freq(void)
{
void __iomem *status_reg = (void __iomem *)0xbf000410;
unsigned int freq, orig, tick = 0;
unsigned long flags;
local_irq_save(flags);
orig = readl(status_reg) & 0x2; /* get original sample */
/* wait for transition */
while ((readl(status_reg) & 0x2) == orig)
;
orig = orig ^ 0x2; /* flip the bit */
write_c0_count(0);
/* wait 1 second (the sampling clock transitions every 10ms) */
while (tick < 100) {
/* wait for transition */
while ((readl(status_reg) & 0x2) == orig)
;
orig = orig ^ 0x2; /* flip the bit */
tick++;
}
freq = read_c0_count();
local_irq_restore(flags);
return freq;
}
extern char __dtb_sead3_begin[];
MIPS_MACHINE(sead3) = {
.fdt = __dtb_sead3_begin,
.detect = sead3_detect,
.fixup_fdt = sead3_fixup_fdt,
.measure_hpt_freq = sead3_measure_hpt_freq,
};