58 lines
1.0 KiB
C
58 lines
1.0 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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* Reset a Jazz machine.
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*
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* We don't trust the firmware so we do it the classic way by poking and
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* stabbing at the keyboard controller ...
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*/
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#include <linux/jiffies.h>
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#include <asm/jazz.h>
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#define KBD_STAT_IBF 0x02 /* Keyboard input buffer full */
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static void jazz_write_output(unsigned char val)
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{
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int status;
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do {
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status = jazz_kh->command;
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} while (status & KBD_STAT_IBF);
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jazz_kh->data = val;
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}
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static void jazz_write_command(unsigned char val)
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{
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int status;
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do {
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status = jazz_kh->command;
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} while (status & KBD_STAT_IBF);
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jazz_kh->command = val;
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}
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static unsigned char jazz_read_status(void)
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{
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return jazz_kh->command;
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}
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static inline void kb_wait(void)
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{
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unsigned long start = jiffies;
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unsigned long timeout = start + HZ/2;
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do {
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if (! (jazz_read_status() & 0x02))
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return;
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} while (time_before_eq(jiffies, timeout));
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}
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void jazz_machine_restart(char *command)
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{
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while(1) {
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kb_wait();
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jazz_write_command(0xd1);
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kb_wait();
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jazz_write_output(0x00);
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}
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}
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