From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- arch/mips/jazz/reset.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 arch/mips/jazz/reset.c (limited to 'arch/mips/jazz/reset.c') 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 +#include + +#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); + } +} -- cgit v1.2.3