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d3b41b6bb4
A multi-platform kernel binary has to decide at run-time how to dispatch the arch_nvram_ops calls. Add a platform-independent arch_nvram_ops struct for this, to replace the atari-specific one. Enable CONFIG_HAVE_ARCH_NVRAM_OPS for Macs. Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
272 lines
6.6 KiB
C
272 lines
6.6 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* CMOS/NV-RAM driver for Atari. Adapted from drivers/char/nvram.c.
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* Copyright (C) 1997 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
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* idea by and with help from Richard Jelinek <rj@suse.de>
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* Portions copyright (c) 2001,2002 Sun Microsystems (thockin@sun.com)
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* Further contributions from Cesar Barros, Erik Gilling, Tim Hockin and
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* Wim Van Sebroeck.
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*/
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/mc146818rtc.h>
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#include <linux/module.h>
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#include <linux/nvram.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/spinlock.h>
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#include <linux/types.h>
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#include <asm/atarihw.h>
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#include <asm/atariints.h>
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#define NVRAM_BYTES 50
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/* It is worth noting that these functions all access bytes of general
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* purpose memory in the NVRAM - that is to say, they all add the
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* NVRAM_FIRST_BYTE offset. Pass them offsets into NVRAM as if you did not
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* know about the RTC cruft.
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*/
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/* Note that *all* calls to CMOS_READ and CMOS_WRITE must be done with
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* rtc_lock held. Due to the index-port/data-port design of the RTC, we
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* don't want two different things trying to get to it at once. (e.g. the
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* periodic 11 min sync from kernel/time/ntp.c vs. this driver.)
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*/
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static unsigned char __nvram_read_byte(int i)
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{
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return CMOS_READ(NVRAM_FIRST_BYTE + i);
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}
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/* This races nicely with trying to read with checksum checking */
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static void __nvram_write_byte(unsigned char c, int i)
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{
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CMOS_WRITE(c, NVRAM_FIRST_BYTE + i);
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}
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/* On Ataris, the checksum is over all bytes except the checksum bytes
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* themselves; these are at the very end.
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*/
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#define ATARI_CKS_RANGE_START 0
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#define ATARI_CKS_RANGE_END 47
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#define ATARI_CKS_LOC 48
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static int __nvram_check_checksum(void)
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{
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int i;
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unsigned char sum = 0;
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for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
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sum += __nvram_read_byte(i);
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return (__nvram_read_byte(ATARI_CKS_LOC) == (~sum & 0xff)) &&
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(__nvram_read_byte(ATARI_CKS_LOC + 1) == (sum & 0xff));
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}
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static void __nvram_set_checksum(void)
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{
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int i;
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unsigned char sum = 0;
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for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
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sum += __nvram_read_byte(i);
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__nvram_write_byte(~sum, ATARI_CKS_LOC);
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__nvram_write_byte(sum, ATARI_CKS_LOC + 1);
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}
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long atari_nvram_set_checksum(void)
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{
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spin_lock_irq(&rtc_lock);
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__nvram_set_checksum();
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spin_unlock_irq(&rtc_lock);
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return 0;
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}
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long atari_nvram_initialize(void)
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{
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loff_t i;
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spin_lock_irq(&rtc_lock);
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for (i = 0; i < NVRAM_BYTES; ++i)
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__nvram_write_byte(0, i);
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__nvram_set_checksum();
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spin_unlock_irq(&rtc_lock);
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return 0;
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}
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ssize_t atari_nvram_read(char *buf, size_t count, loff_t *ppos)
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{
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char *p = buf;
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loff_t i;
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spin_lock_irq(&rtc_lock);
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if (!__nvram_check_checksum()) {
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spin_unlock_irq(&rtc_lock);
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return -EIO;
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}
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for (i = *ppos; count > 0 && i < NVRAM_BYTES; --count, ++i, ++p)
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*p = __nvram_read_byte(i);
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spin_unlock_irq(&rtc_lock);
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*ppos = i;
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return p - buf;
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}
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ssize_t atari_nvram_write(char *buf, size_t count, loff_t *ppos)
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{
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char *p = buf;
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loff_t i;
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spin_lock_irq(&rtc_lock);
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if (!__nvram_check_checksum()) {
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spin_unlock_irq(&rtc_lock);
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return -EIO;
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}
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for (i = *ppos; count > 0 && i < NVRAM_BYTES; --count, ++i, ++p)
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__nvram_write_byte(*p, i);
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__nvram_set_checksum();
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spin_unlock_irq(&rtc_lock);
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*ppos = i;
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return p - buf;
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}
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ssize_t atari_nvram_get_size(void)
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{
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return NVRAM_BYTES;
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}
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#ifdef CONFIG_PROC_FS
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static struct {
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unsigned char val;
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const char *name;
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} boot_prefs[] = {
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{ 0x80, "TOS" },
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{ 0x40, "ASV" },
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{ 0x20, "NetBSD (?)" },
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{ 0x10, "Linux" },
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{ 0x00, "unspecified" },
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};
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static const char * const languages[] = {
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"English (US)",
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"German",
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"French",
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"English (UK)",
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"Spanish",
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"Italian",
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"6 (undefined)",
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"Swiss (French)",
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"Swiss (German)",
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};
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static const char * const dateformat[] = {
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"MM%cDD%cYY",
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"DD%cMM%cYY",
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"YY%cMM%cDD",
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"YY%cDD%cMM",
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"4 (undefined)",
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"5 (undefined)",
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"6 (undefined)",
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"7 (undefined)",
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};
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static const char * const colors[] = {
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"2", "4", "16", "256", "65536", "??", "??", "??"
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};
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static void atari_nvram_proc_read(unsigned char *nvram, struct seq_file *seq,
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void *offset)
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{
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int checksum;
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int i;
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unsigned int vmode;
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spin_lock_irq(&rtc_lock);
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checksum = __nvram_check_checksum();
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spin_unlock_irq(&rtc_lock);
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seq_printf(seq, "Checksum status : %svalid\n", checksum ? "" : "not ");
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seq_puts(seq, "Boot preference : ");
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for (i = ARRAY_SIZE(boot_prefs) - 1; i >= 0; --i)
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if (nvram[1] == boot_prefs[i].val) {
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seq_printf(seq, "%s\n", boot_prefs[i].name);
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break;
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}
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if (i < 0)
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seq_printf(seq, "0x%02x (undefined)\n", nvram[1]);
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seq_printf(seq, "SCSI arbitration : %s\n",
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(nvram[16] & 0x80) ? "on" : "off");
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seq_puts(seq, "SCSI host ID : ");
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if (nvram[16] & 0x80)
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seq_printf(seq, "%d\n", nvram[16] & 7);
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else
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seq_puts(seq, "n/a\n");
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if (!MACH_IS_FALCON)
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return;
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seq_puts(seq, "OS language : ");
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if (nvram[6] < ARRAY_SIZE(languages))
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seq_printf(seq, "%s\n", languages[nvram[6]]);
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else
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seq_printf(seq, "%u (undefined)\n", nvram[6]);
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seq_puts(seq, "Keyboard language: ");
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if (nvram[7] < ARRAY_SIZE(languages))
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seq_printf(seq, "%s\n", languages[nvram[7]]);
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else
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seq_printf(seq, "%u (undefined)\n", nvram[7]);
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seq_puts(seq, "Date format : ");
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seq_printf(seq, dateformat[nvram[8] & 7],
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nvram[9] ? nvram[9] : '/', nvram[9] ? nvram[9] : '/');
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seq_printf(seq, ", %dh clock\n", nvram[8] & 16 ? 24 : 12);
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seq_puts(seq, "Boot delay : ");
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if (nvram[10] == 0)
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seq_puts(seq, "default\n");
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else
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seq_printf(seq, "%ds%s\n", nvram[10],
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nvram[10] < 8 ? ", no memory test" : "");
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vmode = (nvram[14] << 8) | nvram[15];
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seq_printf(seq,
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"Video mode : %s colors, %d columns, %s %s monitor\n",
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colors[vmode & 7], vmode & 8 ? 80 : 40,
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vmode & 16 ? "VGA" : "TV", vmode & 32 ? "PAL" : "NTSC");
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seq_printf(seq,
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" %soverscan, compat. mode %s%s\n",
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vmode & 64 ? "" : "no ", vmode & 128 ? "on" : "off",
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vmode & 256 ?
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(vmode & 16 ? ", line doubling" : ", half screen") : "");
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}
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static int nvram_proc_read(struct seq_file *seq, void *offset)
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{
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unsigned char contents[NVRAM_BYTES];
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int i;
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spin_lock_irq(&rtc_lock);
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for (i = 0; i < NVRAM_BYTES; ++i)
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contents[i] = __nvram_read_byte(i);
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spin_unlock_irq(&rtc_lock);
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atari_nvram_proc_read(contents, seq, offset);
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return 0;
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}
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static int __init atari_nvram_init(void)
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{
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if (!(MACH_IS_ATARI && ATARIHW_PRESENT(TT_CLK)))
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return -ENODEV;
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if (!proc_create_single("driver/nvram", 0, NULL, nvram_proc_read)) {
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pr_err("nvram: can't create /proc/driver/nvram\n");
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return -ENOMEM;
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}
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return 0;
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}
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device_initcall(atari_nvram_init);
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#endif /* CONFIG_PROC_FS */
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