/* * Copyright 2008-2011, IBM Corporation * * 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. */ #include <linux/kernel.h> #include <linux/of.h> #include <linux/io.h> #include <linux/of_address.h> #include "wsp.h" /* * The UART connection to the H8 is over ttyS1 which is just a 16550. * We assume that FW has it setup right and no one messes with it. */ static u8 __iomem *h8; #define RBR 0 /* Receiver Buffer Register */ #define THR 0 /* Transmitter Holding Register */ #define LSR 5 /* Line Status Register */ #define LSR_DR 0x01 /* LSR value for Data-Ready */ #define LSR_THRE 0x20 /* LSR value for Transmitter-Holding-Register-Empty */ static void wsp_h8_putc(int c) { u8 lsr; do { lsr = readb(h8 + LSR); } while ((lsr & LSR_THRE) != LSR_THRE); writeb(c, h8 + THR); } static int wsp_h8_getc(void) { u8 lsr; do { lsr = readb(h8 + LSR); } while ((lsr & LSR_DR) != LSR_DR); return readb(h8 + RBR); } static void wsp_h8_puts(const char *s, int sz) { int i; for (i = 0; i < sz; i++) { wsp_h8_putc(s[i]); /* no flow control so wait for echo */ wsp_h8_getc(); } wsp_h8_putc('\r'); wsp_h8_putc('\n'); } static void wsp_h8_terminal_cmd(const char *cmd, int sz) { hard_irq_disable(); wsp_h8_puts(cmd, sz); /* should never return, but just in case */ for (;;) continue; } void wsp_h8_restart(char *cmd) { static const char restart[] = "warm-reset"; (void)cmd; wsp_h8_terminal_cmd(restart, sizeof(restart) - 1); } void wsp_h8_power_off(void) { static const char off[] = "power-off"; wsp_h8_terminal_cmd(off, sizeof(off) - 1); } static void __iomem *wsp_h8_getaddr(void) { struct device_node *aliases; struct device_node *uart; struct property *path; void __iomem *va = NULL; /* * there is nothing in the devtree to tell us which is mapped * to the H8, but se know it is the second serial port. */ aliases = of_find_node_by_path("/aliases"); if (aliases == NULL) return NULL; path = of_find_property(aliases, "serial1", NULL); if (path == NULL) goto out; uart = of_find_node_by_path(path->value); if (uart == NULL) goto out; va = of_iomap(uart, 0); /* remove it so no one messes with it */ of_detach_node(uart); of_node_put(uart); out: of_node_put(aliases); return va; } void __init wsp_setup_h8(void) { h8 = wsp_h8_getaddr(); /* Devtree change? lets hard map it anyway */ if (h8 == NULL) { pr_warn("UART to H8 could not be found"); h8 = ioremap(0xffc0008000ULL, 0x100); } }