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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/mips/jazz/reset.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/mips/jazz/reset.c')
-rw-r--r-- | arch/mips/jazz/reset.c | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/arch/mips/jazz/reset.c b/arch/mips/jazz/reset.c new file mode 100644 index 000000000..052b01f5d --- /dev/null +++ b/arch/mips/jazz/reset.c @@ -0,0 +1,57 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Reset a Jazz machine. + * + * We don't trust the firmware so we do it the classic way by poking and + * stabbing at the keyboard controller ... + */ +#include <linux/jiffies.h> +#include <asm/jazz.h> + +#define KBD_STAT_IBF 0x02 /* Keyboard input buffer full */ + +static void jazz_write_output(unsigned char val) +{ + int status; + + do { + status = jazz_kh->command; + } while (status & KBD_STAT_IBF); + jazz_kh->data = val; +} + +static void jazz_write_command(unsigned char val) +{ + int status; + + do { + status = jazz_kh->command; + } while (status & KBD_STAT_IBF); + jazz_kh->command = val; +} + +static unsigned char jazz_read_status(void) +{ + return jazz_kh->command; +} + +static inline void kb_wait(void) +{ + unsigned long start = jiffies; + unsigned long timeout = start + HZ/2; + + do { + if (! (jazz_read_status() & 0x02)) + return; + } while (time_before_eq(jiffies, timeout)); +} + +void jazz_machine_restart(char *command) +{ + while(1) { + kb_wait(); + jazz_write_command(0xd1); + kb_wait(); + jazz_write_output(0x00); + } +} |