2 * Copyright 2008-2011, IBM Corporation
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
10 #include <linux/kernel.h>
13 #include <linux/of_address.h>
18 * The UART connection to the H8 is over ttyS1 which is just a 16550.
19 * We assume that FW has it setup right and no one messes with it.
23 static u8 __iomem *h8;
25 #define RBR 0 /* Receiver Buffer Register */
26 #define THR 0 /* Transmitter Holding Register */
27 #define LSR 5 /* Line Status Register */
28 #define LSR_DR 0x01 /* LSR value for Data-Ready */
29 #define LSR_THRE 0x20 /* LSR value for Transmitter-Holding-Register-Empty */
30 static void wsp_h8_putc(int c)
35 lsr = readb(h8 + LSR);
36 } while ((lsr & LSR_THRE) != LSR_THRE);
40 static int wsp_h8_getc(void)
45 lsr = readb(h8 + LSR);
46 } while ((lsr & LSR_DR) != LSR_DR);
48 return readb(h8 + RBR);
51 static void wsp_h8_puts(const char *s, int sz)
55 for (i = 0; i < sz; i++) {
58 /* no flow control so wait for echo */
65 static void wsp_h8_terminal_cmd(const char *cmd, int sz)
69 /* should never return, but just in case */
75 void wsp_h8_restart(char *cmd)
77 static const char restart[] = "warm-reset";
80 wsp_h8_terminal_cmd(restart, sizeof(restart) - 1);
83 void wsp_h8_power_off(void)
85 static const char off[] = "power-off";
87 wsp_h8_terminal_cmd(off, sizeof(off) - 1);
90 static void __iomem *wsp_h8_getaddr(void)
92 struct device_node *aliases;
93 struct device_node *uart;
94 struct property *path;
95 void __iomem *va = NULL;
98 * there is nothing in the devtree to tell us which is mapped
99 * to the H8, but se know it is the second serial port.
102 aliases = of_find_node_by_path("/aliases");
106 path = of_find_property(aliases, "serial1", NULL);
110 uart = of_find_node_by_path(path->value);
114 va = of_iomap(uart, 0);
116 /* remove it so no one messes with it */
117 of_detach_node(uart);
121 of_node_put(aliases);
126 void __init wsp_setup_h8(void)
128 h8 = wsp_h8_getaddr();
130 /* Devtree change? lets hard map it anyway */
132 pr_warn("UART to H8 could not be found");
133 h8 = ioremap(0xffc0008000ULL, 0x100);