From 3f5f0a4475e13345326061f00c68f428232ba2bc Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Wed, 5 Oct 2016 18:18:21 +0100 Subject: MIPS: generic: Convert SEAD-3 to a generic board Convert the MIPS SEAD-3 board support to be a generic board, supported by generic kernels. Because the SEAD-3 boot protocol was defined long ago and we don't want to force a switch to the UHI protocol, SEAD-3 is added as a legacy board which is detected by reading the REVISION register. This may technically not be a valid memory read & future work will include attempting to handle that gracefully. In practice since SEAD-3 is the only legacy board supported by the generic kernel so far the read will only happen on SEAD-3 boards, and even once Malta is converted the same REVISION register exists there too. Other boards such as Boston, Ci20 & Ci40 will use the UHI boot protocol & thus not run any of the legacy board detect functions. Signed-off-by: Paul Burton Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/14354/ Signed-off-by: Ralf Baechle --- arch/mips/generic/Kconfig | 7 + arch/mips/generic/Makefile | 2 + arch/mips/generic/board-sead3.c | 376 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 385 insertions(+) create mode 100644 arch/mips/generic/board-sead3.c (limited to 'arch/mips/generic') diff --git a/arch/mips/generic/Kconfig b/arch/mips/generic/Kconfig index baddb0646b23..a606b3f9196c 100644 --- a/arch/mips/generic/Kconfig +++ b/arch/mips/generic/Kconfig @@ -9,4 +9,11 @@ config LEGACY_BOARDS kernel is booted without being provided with an FDT via the UHI boot protocol. +config LEGACY_BOARD_SEAD3 + bool "Support MIPS SEAD-3 boards" + select LEGACY_BOARDS + help + Enable this to include support for booting on MIPS SEAD-3 FPGA-based + development boards, which boot using a legacy boot protocol. + endif diff --git a/arch/mips/generic/Makefile b/arch/mips/generic/Makefile index 26e64207f7ad..7c66494151db 100644 --- a/arch/mips/generic/Makefile +++ b/arch/mips/generic/Makefile @@ -11,3 +11,5 @@ obj-y += init.o obj-y += irq.o obj-y += proc.o + +obj-$(CONFIG_LEGACY_BOARD_SEAD3) += board-sead3.o diff --git a/arch/mips/generic/board-sead3.c b/arch/mips/generic/board-sead3.c new file mode 100644 index 000000000000..f4ae0584a33b --- /dev/null +++ b/arch/mips/generic/board-sead3.c @@ -0,0 +1,376 @@ +/* + * Copyright (C) 2016 Imagination Technologies + * Author: Paul Burton + * + * 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 +#include +#include + +#include +#include +#include + +#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, +}; -- cgit