Paul Burton | b6d5e47 | 2016-08-26 15:17:34 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2016 Imagination Technologies |
| 3 | * Author: Paul Burton <paul.burton@imgtec.com> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License as published by the |
| 7 | * Free Software Foundation; either version 2 of the License, or (at your |
| 8 | * option) any later version. |
| 9 | */ |
| 10 | |
| 11 | #define pr_fmt(fmt) "sead3-dtshim: " fmt |
| 12 | |
| 13 | #include <linux/errno.h> |
| 14 | #include <linux/libfdt.h> |
| 15 | #include <linux/printk.h> |
| 16 | |
Paul Burton | c11e3b4 | 2016-08-26 15:17:35 +0100 | [diff] [blame^] | 17 | #include <asm/fw/fw.h> |
Paul Burton | b6d5e47 | 2016-08-26 15:17:34 +0100 | [diff] [blame] | 18 | #include <asm/io.h> |
| 19 | |
| 20 | #define SEAD_CONFIG CKSEG1ADDR(0x1b100110) |
| 21 | #define SEAD_CONFIG_GIC_PRESENT BIT(1) |
| 22 | |
| 23 | static unsigned char fdt_buf[16 << 10] __initdata; |
| 24 | |
| 25 | static int remove_gic(void *fdt) |
| 26 | { |
Paul Burton | c11e3b4 | 2016-08-26 15:17:35 +0100 | [diff] [blame^] | 27 | const unsigned int cpu_uart_int = 4; |
| 28 | int gic_off, cpu_off, uart_off, err; |
Paul Burton | b6d5e47 | 2016-08-26 15:17:34 +0100 | [diff] [blame] | 29 | uint32_t cfg, cpu_phandle; |
| 30 | |
| 31 | /* leave the GIC node intact if a GIC is present */ |
| 32 | cfg = __raw_readl((uint32_t *)SEAD_CONFIG); |
| 33 | if (cfg & SEAD_CONFIG_GIC_PRESENT) |
| 34 | return 0; |
| 35 | |
| 36 | gic_off = fdt_node_offset_by_compatible(fdt, -1, "mti,gic"); |
| 37 | if (gic_off < 0) { |
| 38 | pr_err("unable to find DT GIC node: %d\n", gic_off); |
| 39 | return gic_off; |
| 40 | } |
| 41 | |
| 42 | err = fdt_nop_node(fdt, gic_off); |
| 43 | if (err) { |
| 44 | pr_err("unable to nop GIC node\n"); |
| 45 | return err; |
| 46 | } |
| 47 | |
| 48 | cpu_off = fdt_node_offset_by_compatible(fdt, -1, |
| 49 | "mti,cpu-interrupt-controller"); |
| 50 | if (cpu_off < 0) { |
| 51 | pr_err("unable to find CPU intc node: %d\n", cpu_off); |
| 52 | return cpu_off; |
| 53 | } |
| 54 | |
| 55 | cpu_phandle = fdt_get_phandle(fdt, cpu_off); |
| 56 | if (!cpu_phandle) { |
| 57 | pr_err("unable to get CPU intc phandle\n"); |
| 58 | return -EINVAL; |
| 59 | } |
| 60 | |
| 61 | err = fdt_setprop_u32(fdt, 0, "interrupt-parent", cpu_phandle); |
| 62 | if (err) { |
| 63 | pr_err("unable to set root interrupt-parent: %d\n", err); |
| 64 | return err; |
| 65 | } |
| 66 | |
Paul Burton | c11e3b4 | 2016-08-26 15:17:35 +0100 | [diff] [blame^] | 67 | uart_off = fdt_node_offset_by_compatible(fdt, -1, "ns16550a"); |
| 68 | while (uart_off >= 0) { |
| 69 | err = fdt_setprop_u32(fdt, uart_off, "interrupts", |
| 70 | cpu_uart_int); |
| 71 | if (err) { |
| 72 | pr_err("unable to set UART interrupts property: %d\n", |
| 73 | err); |
| 74 | return err; |
| 75 | } |
| 76 | |
| 77 | uart_off = fdt_node_offset_by_compatible(fdt, uart_off, |
| 78 | "ns16550a"); |
| 79 | } |
| 80 | if (uart_off != -FDT_ERR_NOTFOUND) { |
| 81 | pr_err("error searching for UART DT node: %d\n", uart_off); |
| 82 | return uart_off; |
| 83 | } |
| 84 | |
| 85 | return 0; |
| 86 | } |
| 87 | |
| 88 | static int serial_config(void *fdt) |
| 89 | { |
| 90 | const char *yamontty, *mode_var; |
| 91 | char mode_var_name[9], path[18], parity; |
| 92 | unsigned int uart, baud, stop_bits; |
| 93 | bool hw_flow; |
| 94 | int chosen_off, err; |
| 95 | |
| 96 | yamontty = fw_getenv("yamontty"); |
| 97 | if (!yamontty || !strcmp(yamontty, "tty0")) { |
| 98 | uart = 0; |
| 99 | } else if (!strcmp(yamontty, "tty1")) { |
| 100 | uart = 1; |
| 101 | } else { |
| 102 | pr_warn("yamontty environment variable '%s' invalid\n", |
| 103 | yamontty); |
| 104 | uart = 0; |
| 105 | } |
| 106 | |
| 107 | baud = stop_bits = 0; |
| 108 | parity = 0; |
| 109 | hw_flow = false; |
| 110 | |
| 111 | snprintf(mode_var_name, sizeof(mode_var_name), "modetty%u", uart); |
| 112 | mode_var = fw_getenv(mode_var_name); |
| 113 | if (mode_var) { |
| 114 | while (mode_var[0] >= '0' && mode_var[0] <= '9') { |
| 115 | baud *= 10; |
| 116 | baud += mode_var[0] - '0'; |
| 117 | mode_var++; |
| 118 | } |
| 119 | if (mode_var[0] == ',') |
| 120 | mode_var++; |
| 121 | if (mode_var[0]) |
| 122 | parity = mode_var[0]; |
| 123 | if (mode_var[0] == ',') |
| 124 | mode_var++; |
| 125 | if (mode_var[0]) |
| 126 | stop_bits = mode_var[0] - '0'; |
| 127 | if (mode_var[0] == ',') |
| 128 | mode_var++; |
| 129 | if (!strcmp(mode_var, "hw")) |
| 130 | hw_flow = true; |
| 131 | } |
| 132 | |
| 133 | if (!baud) |
| 134 | baud = 38400; |
| 135 | |
| 136 | if (parity != 'e' && parity != 'n' && parity != 'o') |
| 137 | parity = 'n'; |
| 138 | |
| 139 | if (stop_bits != 7 && stop_bits != 8) |
| 140 | stop_bits = 8; |
| 141 | |
| 142 | WARN_ON(snprintf(path, sizeof(path), "uart%u:%u%c%u%s", |
| 143 | uart, baud, parity, stop_bits, |
| 144 | hw_flow ? "r" : "") >= sizeof(path)); |
| 145 | |
| 146 | /* find or add chosen node */ |
| 147 | chosen_off = fdt_path_offset(fdt, "/chosen"); |
| 148 | if (chosen_off == -FDT_ERR_NOTFOUND) |
| 149 | chosen_off = fdt_path_offset(fdt, "/chosen@0"); |
| 150 | if (chosen_off == -FDT_ERR_NOTFOUND) |
| 151 | chosen_off = fdt_add_subnode(fdt, 0, "chosen"); |
| 152 | if (chosen_off < 0) { |
| 153 | pr_err("Unable to find or add DT chosen node: %d\n", |
| 154 | chosen_off); |
| 155 | return chosen_off; |
| 156 | } |
| 157 | |
| 158 | err = fdt_setprop_string(fdt, chosen_off, "stdout-path", path); |
| 159 | if (err) { |
| 160 | pr_err("Unable to set stdout-path property: %d\n", err); |
| 161 | return err; |
| 162 | } |
| 163 | |
Paul Burton | b6d5e47 | 2016-08-26 15:17:34 +0100 | [diff] [blame] | 164 | return 0; |
| 165 | } |
| 166 | |
| 167 | void __init *sead3_dt_shim(void *fdt) |
| 168 | { |
| 169 | int err; |
| 170 | |
| 171 | if (fdt_check_header(fdt)) |
| 172 | panic("Corrupt DT"); |
| 173 | |
| 174 | /* if this isn't SEAD3, leave the DT alone */ |
| 175 | if (fdt_node_check_compatible(fdt, 0, "mti,sead-3")) |
| 176 | return fdt; |
| 177 | |
| 178 | err = fdt_open_into(fdt, fdt_buf, sizeof(fdt_buf)); |
| 179 | if (err) |
| 180 | panic("Unable to open FDT: %d", err); |
| 181 | |
| 182 | err = remove_gic(fdt_buf); |
| 183 | if (err) |
| 184 | panic("Unable to patch FDT: %d", err); |
| 185 | |
Paul Burton | c11e3b4 | 2016-08-26 15:17:35 +0100 | [diff] [blame^] | 186 | err = serial_config(fdt_buf); |
| 187 | if (err) |
| 188 | panic("Unable to patch FDT: %d", err); |
| 189 | |
Paul Burton | b6d5e47 | 2016-08-26 15:17:34 +0100 | [diff] [blame] | 190 | err = fdt_pack(fdt_buf); |
| 191 | if (err) |
| 192 | panic("Unable to pack FDT: %d\n", err); |
| 193 | |
| 194 | return fdt_buf; |
| 195 | } |