Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * Reset a Jazz machine.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  * We don't trust the firmware so we do it the classic way by poking and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  * stabbing at the keyboard controller ...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) #include <linux/jiffies.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) #include <asm/jazz.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #define KBD_STAT_IBF		0x02	/* Keyboard input buffer full */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) static void jazz_write_output(unsigned char val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 	int status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 	do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 		status = jazz_kh->command;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 	} while (status & KBD_STAT_IBF);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 	jazz_kh->data = val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) static void jazz_write_command(unsigned char val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 	int status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 	do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 		status = jazz_kh->command;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 	} while (status & KBD_STAT_IBF);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 	jazz_kh->command = val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) static unsigned char jazz_read_status(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 	return jazz_kh->command;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) static inline void kb_wait(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 	unsigned long start = jiffies;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 	unsigned long timeout = start + HZ/2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 	do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 		if (! (jazz_read_status() & 0x02))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 			return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 	} while (time_before_eq(jiffies, timeout));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) void jazz_machine_restart(char *command)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 	while(1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 		kb_wait();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 		jazz_write_command(0xd1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 		kb_wait();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 		jazz_write_output(0x00);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) }