mirror of
https://github.com/AsahiLinux/u-boot
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d6ba787e32
Quite a few RISC-V emulators and ISS (including Spike) have host transfer interface (HTIF) based console. This patch adds HTIF based console driver for RISC-V platforms which depends totally on DT node for HTIF register base address. Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Philipp Tomsich <philipp.tomsich@vrull.eu> Reviewed-by: Rick Chen <rick@andestech.com> Tested-by: Bin Meng <bmeng.cn@gmail.com>
178 lines
3.9 KiB
C
178 lines
3.9 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Copyright (C) 2022 Ventana Micro Systems Inc.
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*/
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#include <common.h>
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#include <dm.h>
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#include <errno.h>
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#include <fdtdec.h>
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#include <log.h>
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#include <watchdog.h>
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#include <asm/global_data.h>
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#include <asm/io.h>
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#include <linux/compiler.h>
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#include <serial.h>
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#include <linux/err.h>
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DECLARE_GLOBAL_DATA_PTR;
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#define HTIF_DATA_BITS 48
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#define HTIF_DATA_MASK ((1ULL << HTIF_DATA_BITS) - 1)
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#define HTIF_DATA_SHIFT 0
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#define HTIF_CMD_BITS 8
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#define HTIF_CMD_MASK ((1ULL << HTIF_CMD_BITS) - 1)
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#define HTIF_CMD_SHIFT 48
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#define HTIF_DEV_BITS 8
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#define HTIF_DEV_MASK ((1ULL << HTIF_DEV_BITS) - 1)
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#define HTIF_DEV_SHIFT 56
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#define HTIF_DEV_SYSTEM 0
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#define HTIF_DEV_CONSOLE 1
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#define HTIF_CONSOLE_CMD_GETC 0
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#define HTIF_CONSOLE_CMD_PUTC 1
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#if __riscv_xlen == 64
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# define TOHOST_CMD(dev, cmd, payload) \
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(((u64)(dev) << HTIF_DEV_SHIFT) | \
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((u64)(cmd) << HTIF_CMD_SHIFT) | \
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(u64)(payload))
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#else
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# define TOHOST_CMD(dev, cmd, payload) ({ \
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if ((dev) || (cmd)) \
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__builtin_trap(); \
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(payload); })
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#endif
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#define FROMHOST_DEV(fromhost_value) \
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((u64)((fromhost_value) >> HTIF_DEV_SHIFT) & HTIF_DEV_MASK)
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#define FROMHOST_CMD(fromhost_value) \
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((u64)((fromhost_value) >> HTIF_CMD_SHIFT) & HTIF_CMD_MASK)
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#define FROMHOST_DATA(fromhost_value) \
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((u64)((fromhost_value) >> HTIF_DATA_SHIFT) & HTIF_DATA_MASK)
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struct htif_plat {
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void *fromhost;
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void *tohost;
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int console_char;
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};
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static void __check_fromhost(struct htif_plat *plat)
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{
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u64 fh = readq(plat->fromhost);
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if (!fh)
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return;
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writeq(0, plat->fromhost);
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/* this should be from the console */
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if (FROMHOST_DEV(fh) != HTIF_DEV_CONSOLE)
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__builtin_trap();
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switch (FROMHOST_CMD(fh)) {
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case HTIF_CONSOLE_CMD_GETC:
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plat->console_char = 1 + (u8)FROMHOST_DATA(fh);
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break;
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case HTIF_CONSOLE_CMD_PUTC:
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break;
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default:
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__builtin_trap();
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}
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}
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static void __set_tohost(struct htif_plat *plat,
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u64 dev, u64 cmd, u64 data)
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{
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while (readq(plat->tohost))
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__check_fromhost(plat);
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writeq(TOHOST_CMD(dev, cmd, data), plat->tohost);
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}
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static int htif_serial_putc(struct udevice *dev, const char ch)
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{
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struct htif_plat *plat = dev_get_plat(dev);
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__set_tohost(plat, HTIF_DEV_CONSOLE, HTIF_CONSOLE_CMD_PUTC, ch);
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return 0;
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}
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static int htif_serial_getc(struct udevice *dev)
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{
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int ch;
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struct htif_plat *plat = dev_get_plat(dev);
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if (plat->console_char < 0)
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__check_fromhost(plat);
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if (plat->console_char >= 0) {
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ch = plat->console_char;
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plat->console_char = -1;
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__set_tohost(plat, HTIF_DEV_CONSOLE, HTIF_CONSOLE_CMD_GETC, 0);
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return (ch) ? ch - 1 : -EAGAIN;
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}
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return -EAGAIN;
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}
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static int htif_serial_pending(struct udevice *dev, bool input)
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{
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struct htif_plat *plat = dev_get_plat(dev);
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if (!input)
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return 0;
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if (plat->console_char < 0)
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__check_fromhost(plat);
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return (plat->console_char >= 0) ? 1 : 0;
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}
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static int htif_serial_probe(struct udevice *dev)
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{
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struct htif_plat *plat = dev_get_plat(dev);
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/* Queue first getc request */
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__set_tohost(plat, HTIF_DEV_CONSOLE, HTIF_CONSOLE_CMD_GETC, 0);
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return 0;
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}
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static int htif_serial_of_to_plat(struct udevice *dev)
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{
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fdt_addr_t addr;
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struct htif_plat *plat = dev_get_plat(dev);
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addr = dev_read_addr_index(dev, 0);
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if (addr == FDT_ADDR_T_NONE)
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return -ENODEV;
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plat->fromhost = (void *)(uintptr_t)addr;
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plat->tohost = plat->fromhost + sizeof(u64);
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addr = dev_read_addr_index(dev, 1);
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if (addr != FDT_ADDR_T_NONE)
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plat->tohost = (void *)(uintptr_t)addr;
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plat->console_char = -1;
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return 0;
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}
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static const struct dm_serial_ops htif_serial_ops = {
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.putc = htif_serial_putc,
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.getc = htif_serial_getc,
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.pending = htif_serial_pending,
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};
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static const struct udevice_id htif_serial_ids[] = {
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{ .compatible = "ucb,htif0" },
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{ }
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};
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U_BOOT_DRIVER(serial_htif) = {
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.name = "serial_htif",
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.id = UCLASS_SERIAL,
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.of_match = htif_serial_ids,
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.of_to_plat = htif_serial_of_to_plat,
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.plat_auto = sizeof(struct htif_plat),
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.probe = htif_serial_probe,
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.ops = &htif_serial_ops,
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};
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