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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /arch/m68k/atari/nvram.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/m68k/atari/nvram.c')
-rw-r--r-- | arch/m68k/atari/nvram.c | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/arch/m68k/atari/nvram.c b/arch/m68k/atari/nvram.c new file mode 100644 index 0000000000..7000d2443a --- /dev/null +++ b/arch/m68k/atari/nvram.c @@ -0,0 +1,272 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * CMOS/NV-RAM driver for Atari. Adapted from drivers/char/nvram.c. + * Copyright (C) 1997 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de> + * idea by and with help from Richard Jelinek <rj@suse.de> + * Portions copyright (c) 2001,2002 Sun Microsystems (thockin@sun.com) + * Further contributions from Cesar Barros, Erik Gilling, Tim Hockin and + * Wim Van Sebroeck. + */ + +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/mc146818rtc.h> +#include <linux/module.h> +#include <linux/nvram.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/spinlock.h> +#include <linux/types.h> +#include <asm/atarihw.h> +#include <asm/atariints.h> + +#define NVRAM_BYTES 50 + +/* It is worth noting that these functions all access bytes of general + * purpose memory in the NVRAM - that is to say, they all add the + * NVRAM_FIRST_BYTE offset. Pass them offsets into NVRAM as if you did not + * know about the RTC cruft. + */ + +/* Note that *all* calls to CMOS_READ and CMOS_WRITE must be done with + * rtc_lock held. Due to the index-port/data-port design of the RTC, we + * don't want two different things trying to get to it at once. (e.g. the + * periodic 11 min sync from kernel/time/ntp.c vs. this driver.) + */ + +static unsigned char __nvram_read_byte(int i) +{ + return CMOS_READ(NVRAM_FIRST_BYTE + i); +} + +/* This races nicely with trying to read with checksum checking */ +static void __nvram_write_byte(unsigned char c, int i) +{ + CMOS_WRITE(c, NVRAM_FIRST_BYTE + i); +} + +/* On Ataris, the checksum is over all bytes except the checksum bytes + * themselves; these are at the very end. + */ +#define ATARI_CKS_RANGE_START 0 +#define ATARI_CKS_RANGE_END 47 +#define ATARI_CKS_LOC 48 + +static int __nvram_check_checksum(void) +{ + int i; + unsigned char sum = 0; + + for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i) + sum += __nvram_read_byte(i); + return (__nvram_read_byte(ATARI_CKS_LOC) == (~sum & 0xff)) && + (__nvram_read_byte(ATARI_CKS_LOC + 1) == (sum & 0xff)); +} + +static void __nvram_set_checksum(void) +{ + int i; + unsigned char sum = 0; + + for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i) + sum += __nvram_read_byte(i); + __nvram_write_byte(~sum, ATARI_CKS_LOC); + __nvram_write_byte(sum, ATARI_CKS_LOC + 1); +} + +long atari_nvram_set_checksum(void) +{ + spin_lock_irq(&rtc_lock); + __nvram_set_checksum(); + spin_unlock_irq(&rtc_lock); + return 0; +} + +long atari_nvram_initialize(void) +{ + loff_t i; + + spin_lock_irq(&rtc_lock); + for (i = 0; i < NVRAM_BYTES; ++i) + __nvram_write_byte(0, i); + __nvram_set_checksum(); + spin_unlock_irq(&rtc_lock); + return 0; +} + +ssize_t atari_nvram_read(char *buf, size_t count, loff_t *ppos) +{ + char *p = buf; + loff_t i; + + spin_lock_irq(&rtc_lock); + if (!__nvram_check_checksum()) { + spin_unlock_irq(&rtc_lock); + return -EIO; + } + for (i = *ppos; count > 0 && i < NVRAM_BYTES; --count, ++i, ++p) + *p = __nvram_read_byte(i); + spin_unlock_irq(&rtc_lock); + + *ppos = i; + return p - buf; +} + +ssize_t atari_nvram_write(char *buf, size_t count, loff_t *ppos) +{ + char *p = buf; + loff_t i; + + spin_lock_irq(&rtc_lock); + if (!__nvram_check_checksum()) { + spin_unlock_irq(&rtc_lock); + return -EIO; + } + for (i = *ppos; count > 0 && i < NVRAM_BYTES; --count, ++i, ++p) + __nvram_write_byte(*p, i); + __nvram_set_checksum(); + spin_unlock_irq(&rtc_lock); + + *ppos = i; + return p - buf; +} + +ssize_t atari_nvram_get_size(void) +{ + return NVRAM_BYTES; +} + +#ifdef CONFIG_PROC_FS +static struct { + unsigned char val; + const char *name; +} boot_prefs[] = { + { 0x80, "TOS" }, + { 0x40, "ASV" }, + { 0x20, "NetBSD (?)" }, + { 0x10, "Linux" }, + { 0x00, "unspecified" }, +}; + +static const char * const languages[] = { + "English (US)", + "German", + "French", + "English (UK)", + "Spanish", + "Italian", + "6 (undefined)", + "Swiss (French)", + "Swiss (German)", +}; + +static const char * const dateformat[] = { + "MM%cDD%cYY", + "DD%cMM%cYY", + "YY%cMM%cDD", + "YY%cDD%cMM", + "4 (undefined)", + "5 (undefined)", + "6 (undefined)", + "7 (undefined)", +}; + +static const char * const colors[] = { + "2", "4", "16", "256", "65536", "??", "??", "??" +}; + +static void atari_nvram_proc_read(unsigned char *nvram, struct seq_file *seq, + void *offset) +{ + int checksum; + int i; + unsigned int vmode; + + spin_lock_irq(&rtc_lock); + checksum = __nvram_check_checksum(); + spin_unlock_irq(&rtc_lock); + + seq_printf(seq, "Checksum status : %svalid\n", checksum ? "" : "not "); + + seq_puts(seq, "Boot preference : "); + for (i = ARRAY_SIZE(boot_prefs) - 1; i >= 0; --i) + if (nvram[1] == boot_prefs[i].val) { + seq_printf(seq, "%s\n", boot_prefs[i].name); + break; + } + if (i < 0) + seq_printf(seq, "0x%02x (undefined)\n", nvram[1]); + + seq_printf(seq, "SCSI arbitration : %s\n", + (nvram[16] & 0x80) ? "on" : "off"); + seq_puts(seq, "SCSI host ID : "); + if (nvram[16] & 0x80) + seq_printf(seq, "%d\n", nvram[16] & 7); + else + seq_puts(seq, "n/a\n"); + + if (!MACH_IS_FALCON) + return; + + seq_puts(seq, "OS language : "); + if (nvram[6] < ARRAY_SIZE(languages)) + seq_printf(seq, "%s\n", languages[nvram[6]]); + else + seq_printf(seq, "%u (undefined)\n", nvram[6]); + seq_puts(seq, "Keyboard language: "); + if (nvram[7] < ARRAY_SIZE(languages)) + seq_printf(seq, "%s\n", languages[nvram[7]]); + else + seq_printf(seq, "%u (undefined)\n", nvram[7]); + seq_puts(seq, "Date format : "); + seq_printf(seq, dateformat[nvram[8] & 7], + nvram[9] ? nvram[9] : '/', nvram[9] ? nvram[9] : '/'); + seq_printf(seq, ", %dh clock\n", nvram[8] & 16 ? 24 : 12); + seq_puts(seq, "Boot delay : "); + if (nvram[10] == 0) + seq_puts(seq, "default\n"); + else + seq_printf(seq, "%ds%s\n", nvram[10], + nvram[10] < 8 ? ", no memory test" : ""); + + vmode = (nvram[14] << 8) | nvram[15]; + seq_printf(seq, + "Video mode : %s colors, %d columns, %s %s monitor\n", + colors[vmode & 7], vmode & 8 ? 80 : 40, + vmode & 16 ? "VGA" : "TV", vmode & 32 ? "PAL" : "NTSC"); + seq_printf(seq, + " %soverscan, compat. mode %s%s\n", + vmode & 64 ? "" : "no ", vmode & 128 ? "on" : "off", + vmode & 256 ? + (vmode & 16 ? ", line doubling" : ", half screen") : ""); +} + +static int nvram_proc_read(struct seq_file *seq, void *offset) +{ + unsigned char contents[NVRAM_BYTES]; + int i; + + spin_lock_irq(&rtc_lock); + for (i = 0; i < NVRAM_BYTES; ++i) + contents[i] = __nvram_read_byte(i); + spin_unlock_irq(&rtc_lock); + + atari_nvram_proc_read(contents, seq, offset); + + return 0; +} + +static int __init atari_nvram_init(void) +{ + if (!(MACH_IS_ATARI && ATARIHW_PRESENT(TT_CLK))) + return -ENODEV; + + if (!proc_create_single("driver/nvram", 0, NULL, nvram_proc_read)) { + pr_err("nvram: can't create /proc/driver/nvram\n"); + return -ENOMEM; + } + + return 0; +} +device_initcall(atari_nvram_init); +#endif /* CONFIG_PROC_FS */ |