// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2016 Imagination Technologies
* Author: Paul Burton <[email protected]>
*/
#define pr_fmt(fmt) "yamon-dt: " fmt
#include <linux/bug.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/libfdt.h>
#include <linux/printk.h>
#include <asm/fw/fw.h>
#include <asm/yamon-dt.h>
#define MAX_MEM_ARRAY_ENTRIES 2
__init int yamon_dt_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_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 unsigned int __init gen_fdt_mem_array(
const struct yamon_mem_region *regions,
__be32 *mem_array,
unsigned int max_entries,
unsigned long memsize)
{
const struct yamon_mem_region *mr;
unsigned long size;
unsigned int entries = 0;
for (mr = regions; mr->size && memsize; ++mr) {
if (entries >= max_entries) {
pr_warn("Number of regions exceeds max %u\n",
max_entries);
break;
}
/* How much of the remaining RAM fits in the next region? */
size = min_t(unsigned long, memsize, mr->size);
memsize -= size;
/* Emit a memory region */
*(mem_array++) = cpu_to_be32(mr->start);
*(mem_array++) = cpu_to_be32(size);
++entries;
/* Discard the next mr->discard bytes */
memsize -= min_t(unsigned long, memsize, mr->discard);
}
return entries;
}
__init int yamon_dt_append_memory(void *fdt,
const struct yamon_mem_region *regions)
{
unsigned long phys_memsize = 0, memsize;
__be32 mem_array[2 * MAX_MEM_ARRAY_ENTRIES];
unsigned int mem_entries;
int i, err, mem_off;
char *var, param_name[10], *var_names[] = {
"ememsize", "memsize",
};
/* find memory size from the bootloader environment */
for (i = 0; i < ARRAY_SIZE(var_names); i++) {
var = fw_getenv(var_names[i]);
if (!var)
continue;
err = kstrtoul(var, 0, &phys_memsize);
if (!err)
break;
pr_warn("Failed to read the '%s' env variable '%s'\n",
var_names[i], var);
}
if (!phys_memsize) {
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 */
for (i = 0; i < ARRAY_SIZE(var_names); i++) {
snprintf(param_name, sizeof(param_name), "%s=", var_names[i]);
var = strstr(arcs_cmdline, param_name);
if (!var)
continue;
memsize = memparse(var + strlen(param_name), 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_entries = gen_fdt_mem_array(regions, mem_array,
MAX_MEM_ARRAY_ENTRIES, phys_memsize);
err = fdt_setprop(fdt, mem_off, "reg",
mem_array, mem_entries * 2 * sizeof(mem_array[0]));
if (err) {
pr_err("Unable to set memory regs property: %d\n", err);
return err;
}
mem_entries = gen_fdt_mem_array(regions, mem_array,
MAX_MEM_ARRAY_ENTRIES, memsize);
err = fdt_setprop(fdt, mem_off, "linux,usable-memory",
mem_array, mem_entries * 2 * sizeof(mem_array[0]));
if (err) {
pr_err("Unable to set linux,usable-memory property: %d\n", err);
return err;
}
return 0;
}
__init int yamon_dt_serial_config(void *fdt)
{
const char *yamontty, *mode_var;
char mode_var_name[9], path[20], 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), "serial%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_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;
}
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