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57 lines
1.0 KiB
57 lines
1.0 KiB
// 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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